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FIELD OF THE INVENTION The present invention relates to systems and methods for monitoring service on communications networks, and particularly to systems and methods that cause minimal disruption to the communications network traffic by using passive monitoring of network traffic data packets. BACKGROUND OF THE INVENTION Internet Service Providers (ISPs) are highly desirous of providing Internet Protocol (IP) services, such as Voice over IP (VoIP) and IPTV, to their customers. In order to provide these high value services, the ISP networks need to provide a high Quality of Service (QoS) even as their networks become more complex. There is, therefore, an increased demand for sophisticated monitoring tools that allow the ISPs to rapidly identify degradation in their networks performance and quickly isolate the root cause of any problems. Such tools are critical for ensuring QoS guarantees and for reducing service downtimes through timely resolution of network problems. These monitoring tools typically monitor network traffic parameters such as delay and packet loss using either active or passive measurements. Active monitoring tools typically inject data packets into the network, or send data packets to applications, in order to obtain measurements of delays or losses. Passive monitoring devices, in contrast, snoop on existing data-packets as they traverse the network lines as normal network traffic. Passive monitoring has the advantage that it does not increase the traffic in the network. This can be critical when a network interface or link becomes congested. During such times, injecting additional traffic into the network for active measurements may exacerbate the very problem that is being diagnosed. The disadvantages of passive measurements, however, include having less control over the measurement process as only existing network traffic is used and that the amount of data that needs to be collected can be enormous. In order to control the costs of a passive monitoring infrastructure and the communication overhead between the monitors and the Network Operations Center (NOC), it is important to carefully select the locations at which passive monitoring probes are placed and the paths they are used to monitor. At the same time, it is important to ensure that the data collected by the monitoring probes is sufficient to provide a comprehensive and timely overview of the network's performance. In particular, it is important to provide enough passive monitoring locations that both a detection set of paths and a diagnostic set of paths can be monitored. A detection set of paths for passive monitoring of a communications network is the minimum set of paths that need to be monitored in order to detect that there is an anomaly somewhere in the network. A diagnostic set of paths is the minimum set of paths that need to be monitored in order to accurately locate and diagnose any anomaly that occurs anywhere in the network. SUMMARY OF THE INVENTION Briefly described, the invention provides a system and method for determining the optimal selection of paths for passively monitoring a communications network in order to detect and diagnose faults, and the optimal location for placing monitoring probes on the network to be able to monitor those paths. In a preferred embodiment of the invention, a diagnostic set of paths, or a close approximation to it, is determined by ensuring that, for all pairs of links in the network, the diagnostic set of paths contains at least one path having only one member of that pair of links. In a preferred embodiment of the invention, a detection set of paths that is a subset of the diagnostic set of paths is determined by ensuring that, for all the links in the communications network, there is at least one member of the detection subset of paths that contains that link. During normal operation of the network, only the detection subset of paths needs to be monitored, reducing the amount of data that needs to be collected and reported to a network central control. Once an anomaly is detected, the system may switch to monitoring the full diagnostic set of paths so that the anomaly can be fully diagnosed. The cost of deploying and operating the passive monitoring equipment is minimized by determining a probe location set of links in the communications network. This is the minimum set of links on which a probe needs to be placed in order to monitor the diagnostic set of paths. As the detection set of paths is a subset of the diagnostic set of paths, they will also be monitored by the probe place on the probe location set of links. These and other features of the invention will be more fully understood by references to the following drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of a simple service provider network. FIG. 2A is a schematic representation of a first case of a node in a tree topology having an edge on which a probe can be placed to distinguish an undistinguished edge pair. FIG. 2B is a schematic representation of a second case of a node in a tree topology having an edge on which a probe can be placed to distinguish an undistinguished edge pair. FIG. 2C is a schematic representation of a third case of a node in a tree topology having an edge on which a probe can be placed to distinguish an undistinguished edge pair. FIG. 2D is a schematic representation of a fourth case of a node in a tree topology having an edge on which a probe can be placed to distinguish an undistinguished edge pair. DETAILED DESCRIPTION The present invention provides low-cost, low impact solutions for communications network monitoring infrastructures. In such systems, link level anomalies, such as excessive loss or delay of data packets traversing the network, are inferred from path-level passive measurements, i.e., network faults are monitored by observing the normal traffic flowing across the network. Such monitoring may be performed by placing and operating sophisticated monitoring tools at all nodes in the networks. This simple approach, however, is very costly. In order to reduce the cost, the method of this invention determines the optimum location of data monitoring probes on the network in order to minimize the number of data monitoring probes needed while ensuring that any anomaly that occurs anywhere in the network can be fully diagnosed. Communications networks may be modeled as directed graphs G (V, E) having vertices V and edges E. In such a model, a node v that is an element of V may represent a network router, a switch or a gateway, while the edges of the graph may represent communications links connecting the nodes. A directed communication from a node u to a node v may then be represented by <u, v> and the corresponding undirected physical link by {u, v}. As most modern networks are full-duplex networks, for every directed edge <u i , v i >εE, there is a directed edge <v i , u i >εE. Many Wide Area Networks (WAN) provided by, for instance, Service Providers have a general mesh topology with multiple paths between nodes in order to provide redundant paths. In enterprise environments, however, networks such as Ethernet frames are generally deployed using tree topologies, as they are simpler to implement and are more cost effective. All Internet Protocol (IP) packets in a typical Service Provider communications network originate and terminate at edge routers that interface with customer networks or other service provider networks, and are represented in a graph model of the network by edge nodes that are a subset of nodes from the set V. In an enterprise network, edge nodes may be client hosts or application servers such as web servers or mail servers. The IP traffic between a pair of nodes traverses the network through a sequence of nodes and links dictated by the network topology and routing protocol. For instance, in a Service Provider network, the communication path between a pair of edge nodes may either be a pre-configured Multiprotocol Label Switching (MPLS) or the shortest path between nodes computed used the Open Shortest Path First (OSPF). In a tree topology network the communication path between an edge node pair is unique and traces the edges of the spanning tree. In the graph model of the network, the set of paths between edge nodes are denoted by the set P that has members p, and where each p that is an element of P is a sequence of directed links that the path traverses. For simplicity, we assume that routing is symmetric, i.e., for every path p, there is a path {tilde over (p)} that is an element of P in the opposite direction. However, the schemes discussed in this paper are applicable even if the routing paths are asymmetric. Because passive monitoring relies on observing IP packets traversing the network to detect anomalies, paths with no traffic are not typically included in the set P. In most commercially available routers, data packets get delayed or lost primarily due to queuing at the transmitting or outbound interfaces. Thus, a loss or delay on a directed communication link <v i , v j > can usually be traced back to the outbound interface v i . Hence, a one-to-one correspondence between the link <v i , v j > and the outbound interface v i may be assumed for the purpose of anomaly detection. A passive monitoring infrastructure consists of a set of passive monitoring devices placed at various points in the network where they passively analyze the traffic that passes by. Various devices are available to do the observing. Most commercial routers or switches, for instance, support port mirroring in which each incoming and outgoing packet from one port of the network switch can be copied to another port where the copy of the packet can be studied. There are also hardware devices known as network taps that hook directly into a network cable and send a copy of the traffic that passes through it to one or more other networked devices. A network tap placed on a link between two nodes can measure both forward and reverse traffic on the link and is effectively measuring the incoming and outgoing traffic on the ports at the endpoints of the link. The measurements made by port mirroring and network taps are, therefore, logically equivalent. Passive monitoring devices may include the port mirrors or network taps and any associated local processing device for storing and/or forwarding the information gathered. FIG. 1 is a schematic representation of a simple service provider network 10 , having four passive monitoring devices 12 , five links 14 and twelve possible paths 16 that can be passively monitored if they contain data. For simplicity, FIG. 1 shows only two of the paths 16 . The paths 16 may be represented as <a, v 1 , v 2 , b>, <a, v 1 , v 2 , c>. <a, v 1 , v 2 , d>, <b, v 2 , v 1 , c>, <b, v 2 , d>, <a, v 1 , c> and their inverses. In providing a passive monitoring infrastructure for the service provider network 10 , an objective is to minimize costs by deploying as few passive monitoring devices 12 as possible that will allow the accurate detection and diagnosis of all single link anomalies. In doing this placement, the assumption is that a path reports an anomaly if and only if it contains a link with an anomaly, and that each network anomaly is caused by a single link. The anomalies to be monitored include data packet losses and data packet delays. Excessive data packet losses may be detected by, for instance, using passive monitoring devices tap 1 and tap 2 to monitor the data packets traversing the network via the path p 1 represented by <a, v1, v2, b>. At regular intervals, e.g., 1, 10 or 30 seconds, both tap 1 and tap 2 send to a central Network Operations Center (NOC) the number of packets seen on path p 1 in the most recent time interval. If the difference between the packet counts by tap 1 and tap 2 exceeds a certain pre-specified threshold even after accounting for packets still in transit along the path, then the NOC may conclude that an excessive amount of packets are being lost along some links of the path p. Alternately, the passive monitoring devices tap 1 and tap 2 may send samples of the observed packets on path p 1 to the NOC, and an inference of excessive losses on path p can be made if there is a large discrepancy in the samples from the two passive monitoring devices (also known as probes). Similarly, by associating timestamps with the data packets, it is possible to detect excessive delays along path p by keeping track at the NOC of the difference between packet timestamps averaged over an interval or for sample packets. If an anomaly is reported on path p 1 , additional paths may be monitored in order to determine in which of the links <a, v1>,<v1, v2> or <v2, b> the anomaly has occurred. Assuming that a path reports an anomaly if and only if it contains a link with an anomaly and that the network anomaly is caused by a single link (representing an interface), it is possible to show that a set of monitored paths Q is sufficient to diagnose which is the anomalous link if, for every pair of links (e1, e2) in the set E of the graph G(V, E) representing the network, there is at least one monitored path in Q that contains exactly one of the two links. Probe Placement The probe placement problem solved by the method of this invention may be stated formally along the following lines. Given a directed graph, G=(V, E) and a set of paths P between edge nodes in V, let L represent the set of directed edge-pairs which cannot be distinguished by paths in P. Select the smallest number of undirected edges F on which to place probes so that every link pair in L is distinguished by some edge in F. If each potential probe location edge F is represented by the subset LF of link pairs L that a probe on F will distinguish, then the problem becomes selecting the smallest number of subsets LF that contain all of L, i.e., the union of all selected subsets LF is L. The probe placement problem is, therefore, reduced to a classic Set Cover optimization problem. Given a universe U and a collection of subsets S of U, a set cover is the sub-collection C of the subsets S whose union is U, i.e., a set cover is the sub-collection C that contains all the elements of U. Set Cover optimization comprises finding the smallest sub-collection C that is a set cover. It is well-known that the Set Cover problem is Non-deterministic Polynomial-time (NP) complete, and the optimization version of set cover is NP hard. It is also well-known that that the greedy algorithm is the best-possible polynomial time approximation algorithm for set cover under plausible complexity assumptions. The greedy algorithm for set cover chooses sets according to one rule: at each stage, choose the set which contains the largest number of uncovered elements. For a mesh topology network, the minimum number of probe locations needed for passive monitoring of the network can, therefore, be found by the following greedy algorithm for optimal probe placement: 1. Represent the network as a directed graph G=(V, E); 2. Determine P, the set of paths between edge nodes in V; 3. Determine L, the set of directed edge-pairs which cannot be distinguished by paths in P; 4. Determine F, the set of undirected edges available to have probes placed on them; 5. Represent each member of F by the subset LF of link pairs L that a probe on F will distinguish; 6. Select F corresponding to the largest subset L F ; and 7. Repeat 2 to 6 with P now including all new paths made possible by selecting F until L=0. For tree topology networks, an alternate algorithm can be used to find near optimal probe location. This more restricted problem can be shown to correspond to finding an optimal vertex cover. As vertex cover is known to be NP complete and, therefore, there is unlikely to be an efficient algorithm to solve it. A lazy placement algorithm embodiment of this invention can, however, be shown to be a 3-approximation of the optimal solution, i.e., if the algorithm of this invention produces placement of F probes, and the optimal solution is O probes, |F|≦3|O|. The lazy placement algorithm proceeds bottom up in a tree topology and uses a lazy probe placement strategy, i.e., a link is only selected for placement if it distinguishes a link that cannot be distinguished further up in the tree. TABLE 1 Lazy placement algorithm for solving the probe placement problem in a tree topology network Initially set the solution F(O) = { }, and the set of undistinguished link pairs L(0) = L; for i = 1 to |V| do  Given the set L(i − 1), make local decision for child  edges of n i ;  Add the selected edges to the solution F(i);  Remove the link pairs distinguished by F(i) from  L(i − 1) to get L(i); end In a preferred embodiment of the invention, the algorithm proceeds as follows: Chose a root node; Then proceed bottom up the tree, i.e., before processing any node, process all the node's children; For each node, decide whether to select the child nodes for probe placement, where a child node for node n denotes the edges connecting a node n to its direct children, child(n)={c 1 , c 2 , . . . c m ). A probe on any edge in a tree topology can distinguish a directed link pair if and only if the two links are on either side of it. A child edge {n, c j } of n, therefore, can only distinguish an undistinguished link pair if one of the two directed links in the pair is in the subtree rooted at c j or on {n, c j } and the other is outside the subtree or on {n, c j }. Furthermore, such a link pair is characterized as being a “ripe link”, i.e., a link pair that cannot be distinguished further up the tree if it satisfies one of the four cases illustrated in FIG. 2A , 2 B, 2 C or 2 D. FIG. 2A shows the case in which one, upwardly directed link e 2 is either in the subtree rooted at the child node c j or is <c j n,> and the other upwardly directed link e 1 is on the edge connecting n to its parent. FIG. 2B shows the case in which one, downwardly directed link e 2 is in the subtree rooted at the child node c j o and the other downwardly directed link e 1 is on the link <n, c j >. FIG. 2C shows the case in which one, upwardly directed link e 2 is either in the subtree rooted at the child node c j or is <c j n,> and the other downwardly directed link e 1 is on the edge connecting n to another child. FIG. 2D shows the case in which one, upwardly directed link e 1 is either in the subtree rooted at the child node c j or is <c j n,> and the other downwardly directed link e 2 is in a subtree of another child of n In the cases represented by FIGS. 2A , 2 B and 2 C, the probe is placed on the child edge {n, c j }. In the case represented by 2 D the probe may be placed on either of the two child edges involved, {n, c j } or {n, c k }. The lazy placement algorithm of table 1 ensures that at each step all the ripe pairs in L are distinguished. Each time an edge is added to F, the probe placement solution set, all the link pairs distinguished by it are removed from L. If, from the remaining child edges of n, the subset of child edges which distinguish one or more undistinguished link pairs from L under the case of FIG. 2D can be represented by a set C and the set of those case of FIG. 2D link pairs from L can be represented by a set S. As each pair in S can be distinguished by two child edges, {n, c j } or {n, c k }, the problem of selecting the minimum subset of C such that all the link pairs in S are distinguished can be reduced to the Set Cover problem instance (S, C) with each element belonging to exactly two sets, which is the definition of a Vertex Cover. A Vertex Cover of an undirected graph G=(V,E) is a subset V′ of the vertices of the graph which contains at least one of the two endpoints of each edge. The well known 2-approximation algorithm for Vertex Cover can be used to find a subset of C which distinguishes all the link pairs in S and add the subset to the solution F. The factor-2 approximation algorithm is to repeatedly take both endpoints of an edge into the vertex cover, then remove them from the graph. No better constant-factor approximation is known. Path Selection for Anomaly Detection The problem of path detection for anomaly detection can be stated formally as follows. Given a directed graph G=(V, E) and a set of paths P′ that can be monitored by passive probes, select the minimum subset of paths Q det such that every directed link in E belongs to at least one path in Q det . This may be termed the path cover problem. In a mesh topology, a the path cover problem can be shown to be equivalent to the set cover problem. The greedy algorithm for set cover can, therefore, be used as a logarithmic approximation algorithm for selecting a minimum subset of paths to cover all the directed links. As described above, the greedy algorithm chooses sets according to one rule: at each stage, choose the set which contains the largest number of uncovered elements. In a tree-topology network, a 2-approximation to the optimal path cover in the network is possible. The method consists of selecting a root, then, from each leaf node of the tree, selecting the path that comes closest to the root. Both directions of the path are then included in the solution set. If there are n leaf node vertices, clearly at least n paths are needed to completely cover all the directed links in the network. This is because each path can cover at most two directed links from those incident on the leaf nodes: the link directed from the leaf node at which the path starts to an inner node and the link directed from an inner node to the leaf node at which the path terminates. Thus at least n paths are required to cover the 2n directed links on n leaf nodes. Our solution has 2n paths and so is at least a 2-approximation. If a link is covered by a path, then from one of the leaf nodes serving as endpoints of the path, the link will be on the path from the leaf node to the root, so the link will be covered by the closest path to the root from that leaf node. Therefore, all the links in the tree will be covered by the selected paths. By including both the forward and reverse paths in the solution set, all the directed links will be covered. Path Selection for Anomaly Diagnosis A set of paths Q is sufficient to diagnose an anomalous link, if, for every pair of links (e 1 , e 2 ) in E, there is at least one path in Q that contains exactly one of the two links. Such a path is said to distinguish between the links e 1 and e 2 . Given a network defined as a directed graph G=(V, E) and a set of paths P′ that can be monitored by passive probes, path selection for anomaly diagnosis requires finding the minimum set of paths Q that distinguish all link pairs in E and is a subset of P′. For mesh graph topologies, the anomaly diagnosis problem can be reduced to a set cover problem by reducing each link pair to an element and each path to the set of link pairs it distinguishes. As noted above, a path distinguishes all the links it contains from all the links it does not contain. In this reduction, p={e 1 , e 2 }εP, where e 1 , e 2 εE is reduced to the set {(e 1 , e j )|e j εE, e j {tilde over (ε)}p}∪{(e 2 , e j )|e j εE, e j {tilde over (ε)}p}. The greedy algorithm for set cover can then be used to give a logarithmic factor approximation algorithm to compute a subcollection of paths that distinguishes all the link pairs. In the greedy algorithm, sets are chosen according to one rule: at each stage, choose the set which contains the largest number of uncovered elements. For tree topologies, there is a 12-approximation algorithm for solving the anomaly diagnosis problem. Given a tree T having n vertices, with the edges denoted by E and where P is the required set of paths, the algorithm proceeds by first obtaining a solution in each undirected edge of the tree. Once a diagnosis path set is obtained for an undirected tree network, each path in the solution can be replaced by the corresponding directed paths in both directions in order to differentiate any two directed links. A diagnosis path set should be at least a constant fraction of the number of vertices n in the tree network. Such a diagnosis path set whose size is a constant times n may be chosen as follows: Let the optimal diagnosis path set be D o , a solution be DC and an undirected solution path set D. First, find the undirected path cover using the 2-approximation algorithm detailed above. In this method a root is selected, then, from each leaf node of the tree, selecting the path that comes closest to the root. For the undirected case, any path cover size is at least n 1 /2, and the 2-approximation algorithm gives a path cover size of n 1 where n 1 are the leaf nodes of the tree. Call this undirected path cover set C and make D=C. Second, for each edge e={u e , v e }, fix a path P e in the path cover that covers this edge. Also, denote by s e and t e the end points Of P e and let s e be the end closer to u e . Thirdly, each edge e={u, v} divides the path P e into at most three segments (s e , u e ), (u e , v e ) and (v e , t e ). Among all the paths that pass through e and deviate from P e in the segment (s e , u e ), choose the one that deviates at a vertex closest to u e . Call this path P s,e . Similarly, choose P t,e . If no such path exists, or u e or v e are the endpoints, do not choose the corresponding path. Add the chosen paths to D. The diagnostic path solution set DC can be shown to be a 12-approximation of the optimum solution D o . Although the invention has been described in language specific to structural features and/or methodological acts, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as exemplary forms of implementing the claimed invention. Modifications may readily be devised by those ordinarily skilled in the art without departing from the spirit or scope of the present invention.

A system and method for determining optimal selection of paths for passively monitoring a communications network. A diagnostic set of paths is determined by ensuring that, for all pairs of links in the network, the set contains one path having only one member of that pair. A detection subset of paths is determined by ensuring that, for all the links in the network, one member of the subset contains that link. Selecting a minimum detection and diagnostic set of paths minimizes the communication overhead imposed by monitoring. During normal operation, only the detection subset need be monitored. Once an anomaly is detected, the system may switch to monitoring the full diagnostic set. The cost of deploying and operating the passive monitoring equipment is minimized by determining the minimum set of links on which a probe needs to be placed in order to monitor the diagnostic set of paths.

CROSS REFERENCES TO RELATED APPLICATIONS This application claims priority from and is related to commonly owned U.S. Provisional Patent Application Ser. No. 61/452,450 filed Mar. 14, 2011, entitled: Apparatus for Plasma Dicing a Semi-conductor Wafer, this Provisional Patent Application incorporated by reference herein. This application is a continuation-in-part of co-pending patent application Ser. No. 13/412,119 filed on Mar. 5, 2012, entitled: Method and Apparatus for Plasma Dicing a Semi-conductor Wafer, the contents of which are incorporated herein. FIELD OF THE INVENTION The invention relates to the use of an apparatus for the formation of individual device chips from a semi-conductor wafer, and in particular to an apparatus which uses plasma etching to separate the wafer into individual die. BACKGROUND Semi-conductor devices are fabricated on substrates which are in the form of thin wafers. Silicon is commonly used as the substrate material, but other materials, such as III-V compounds (for example GaAs and InP) are also used. In some instances (for example, the manufacture of LED's) the substrate is a sapphire or silicon carbide wafer on which a thin layer of a semi-conducting material is deposited. The size of such substrates ranges from 2 inches and 3 inches up to 200 mm, 300 mm, and 450 mm diameter and many standards exist (e.g., SEMI) to describe such substrate sizes. Plasma etching equipment is used extensively in the processing of these substrates to produce semi-conductor devices. Such equipment typically includes a vacuum chamber fitted with a high density plasma source such as Inductively Coupled Plasma (ICP) which is used to ensure high etch rates, necessary for cost-effective manufacturing. In order to remove the heat generated during the processing, the substrate is typically clamped to a cooled support. A cooling gas (typically Helium) is maintained between the substrate and the support to provide a thermal conductance path for heat removal. A mechanical clamping mechanism, in which a downward force is applied to the top side of the substrate, may be used, though this may cause contamination due to the contact between the clamp and the substrate. More frequently an Electrostatic chuck (ESC) is used to provide the clamping force. Numerous gas chemistries appropriate to the material to be etched have been developed. These frequently employ a halogen (Fluorine, Chlorine, Bromine, or Iodine) or halogen-containing gas together with additional gases added to improve the quality of the etch (for example, etch anisotropy, mask selectivity and etch uniformity). Fluorine containing gases, such as SF 6 , F 2 or NF 3 are used to etch silicon at a high rate. In particular, a process (Bosch or time division multiplexed “TDM”) which alternates a high rate silicon etch step with a passivation step to control the etch sidewall, is commonly used to etch deep features into silicon. Chlorine and Bromine containing gases are commonly used to etch III-V materials. Plasma etching is not limited to semiconducting substrates and devices. The technique may be applied to any substrate type where a suitable gas chemistry to etch the substrate is available. Other substrate types may include carbon containing substrates (including polymeric substrates), ceramic substrates (e.g., AlTiC and sapphire), metal substrates, and glass substrates. To ensure consistent results, low breakage and ease of operation, robotic wafer handling is typically used in the manufacturing process. Handlers are designed to support the wafers with minimal contact, to minimize possible contamination and reduce the generation of particulates. Edge contact alone, or underside contact close to the wafer edge at only a few locations (typically within 3-6 mm of the wafer edge) is generally employed. Handling schemes, which include wafer cassettes, robotic arms and within process chamber fixtures including the wafer support and ESC, are designed to handle the standard wafer sizes as noted previously. After fabrication on the substrate, the individual devices (die or chips) are separated from each other prior to packaging or being employed in other electronic circuitry. For many years, mechanical means have been used to separate the die from each other. Such mechanical means have included breaking the wafer along scribe lines aligned with the substrate crystal axis or by using a high speed diamond saw to saw into or through the substrate in a region (streets) between the die. More recently, lasers have been used to facilitate the scribing process. Such mechanical wafer dicing techniques have limitations which affect the cost effectiveness of this approach. Chipping and breakage along the die edges can reduce the number of good die produced, and becomes more problematic as wafer thicknesses decrease. The area consumed by the saw bade (kerf) may be greater than 100 microns which is valuable area not useable for die production. For wafers containing small die (e.g., individual semiconductor devices with a die size of 500 microns×500 microns) this can represent a loss of greater than 20%. Further, for wafers with many small die and hence numerous streets, the dicing time is increased, and productivity decreased, since each street is cut individually. Mechanical means are also limited to separation along straight lines and the production of square or oblong shaped chips. This may not represent the underlying device topology (e.g., a high power diode is round) and so the rectilinear die format results in significant loss of useable substrate area. Laser dicing also has limitations by leaving residual material on the die surface or inducing stress into the die. It is important to note that both sawing and laser dicing techniques are essentially serial operations. Consequently, as device sizes decrease, the time to dice the wafer increases in proportion to the total dicing street length on the wafer. Recently plasma etching techniques have been proposed as a means of separating die and overcoming some of these limitations. After device fabrication, the substrate is masked with a suitable mask material, leaving open areas between the die. The masked substrate is then processed using a reactive-gas plasma which etches the substrate material exposed between the die. The plasma etching of the substrate may proceed partially or completely through the substrate. In the case of a partial plasma etch, the die are separated by a subsequent cleaving step, leaving the individual die separated. The technique offers a number of benefits over mechanical dicing: 1) Breakage and chipping is reduced; 2) The kerf dimensions can be reduced to well below 20 microns; 3) Processing time does not increase significantly as the number of die increases; 4) Processing time is reduced for thinner wafers; and 5) Die topology is not limited to a rectilinear format. After device fabrication, but prior to die separation, the substrate may be thinned by mechanical grinding or similar process down to a thickness of a few hundred microns, or even less than a hundred microns. Prior to the dicing process, the substrate is typically mounted on a dicing fixture. This fixture is typically comprised of a rigid frame that supports an adhesive membrane. The substrate to be diced is adhered to the membrane. This fixture holds the separated die for subsequent downstream operations. Most tools used for wafer dicing (saws or laser based tools) are designed to handle substrates in this configuration and a number of standard fixtures have been established; however, such fixtures are very different from the substrates which they support. Though such fixtures are optimized for use in current wafer dicing equipment, they cannot be processed in equipment which has been designed to process standard substrates. Thus, current automated plasma etching equipment is not suitable for processing substrates fixtured for dicing and it is difficult to realize the benefits that plasma etch techniques should have for die separation. Some groups have contemplated using plasma to singulate die from wafer substrates. U.S. Pat. No. 6,642,127 describes a plasma dicing technique in which the substrate wafer is first attached to a carrier wafer via an adhesive material, before plasma processing in equipment designed for processing silicon wafers. This technique proposes adapting the form factor of the substrate to be diced to be compatible with standard wafer processing equipment. While this technique allows standard plasma equipment to dice the wafer, the proposed technique will not be compatible with standard equipment downstream of the dicing operation. Additional steps would be required to either adapt the downstream equipment or revert the substrate form factor for standard downstream equipment. U.S. Patent Application 2010/0048001 contemplates the use of a wafer adhered to a thin membrane and supported within a frame. However, in the 2010/0048001 application, the masking process is achieved by adhering a mask material to the backside of the wafer and using a laser to define the etch streets prior to plasma processing. In contrast to standard dicing techniques which singulate the substrate from the front side, this technique introduces additional complex and expensive steps which may negate some of the advantages of plasma dicing. It also requires the additional demand of aligning the backside mask with the front side device pattern. Therefore, what is needed is a plasma etching apparatus which can be used for dicing a semiconductor substrate into individual die and which is compatible with the established wafer dicing technique of handling a substrate mounted on tape and supported in a frame, and which is also compatible with standard front side masking techniques. Nothing in the prior art provides the benefits attendant with the present invention. Therefore, it is an object of the present invention to provide an improvement which overcomes the inadequacies of the prior art devices and which is a significant contribution to the advancement to the dicing of semiconductor substrates using a plasma etching apparatus. Another object of the present invention is to provide a method for plasma dicing a substrate, the method comprising: providing a process chamber having a wall; providing a plasma source adjacent to the wall of the process chamber; providing a work piece support within the process chamber; placing a work piece onto the work piece support, said work piece having a support film, a frame and the substrate; loading the work piece onto the work piece support; applying a tensional force to the support film; clamping the work piece to the work piece support; generating a plasma using the plasma source; and etching the work piece using the generated plasma. Yet another object of the present invention is to provide a method for plasma dicing a substrate, the method comprising: providing a process chamber having a wall; providing a plasma source adjacent to the wall of the process chamber; providing a work piece support within the process chamber; placing a work piece onto the work piece support, said work piece having a support film, a frame and the substrate; loading the work piece onto the work piece support; positioning the frame non-coplanar to the substrate on the work piece support; clamping the work piece to the work piece support; generating a plasma using the plasma source; and etching the work piece using the generated plasma. Still yet another object of the present invention is to provide a method for plasma dicing a substrate, the method comprising: providing a process chamber having a wall; providing a plasma source adjacent to the wall of the process chamber; providing a work piece support within the process chamber; placing a work piece onto the work piece support, said work piece having a support film, a frame and the substrate; loading the work piece onto the work piece support; applying a tensional force to the support film; generating a plasma using the plasma source; and etching the work piece using the generated plasma. Another object of the present invention is to provide a method for plasma dicing a plurality of substrates, the method comprising: providing a process chamber having a wall; providing a plasma source adjacent to the wall of the process chamber; providing a work piece support within the process chamber; placing a work piece onto the work piece support, said work piece having a support film, a frame and the plurality of substrates; loading the work piece onto the work piece support; clamping the work piece to the work piece support; generating a plasma using the plasma source; and etching the work piece using the generated plasma. The foregoing has outlined some of the pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. SUMMARY OF THE INVENTION The present invention describes a plasma processing apparatus which allows for plasma dicing of a semiconductor substrate. After device fabrication and wafer thinning, the front side (circuit side) of the substrate is masked using conventional masking techniques which protects the circuit components and leaves unprotected areas between the die. The substrate is mounted on a thin tape which is supported within a rigid frame. The substrate/tape/frame assembly is transferred into a vacuum processing chamber and exposed to reactive gas plasma where the unprotected areas between the die are etched away. During this process, the frame and tape are protected from damage by the reactive gas plasma. The processing leaves the die completely separated. After etching, the substrate/tape/frame assembly is additionally exposed to plasma which removes potentially damaging residues from the substrate surface. After transfer of the substrate/tape/frame assembly out of the process chamber, the die are removed from the tape using well known techniques and are then further processed (e.g., packaged) as necessary. Another feature of the present invention is to provide a method for plasma dicing a substrate. The substrate can have a semiconducting layer such as Silicon and/or the substrate can have a III-V layer such as GaAs. The substrate can have a protective layer such as a photoresist layer that is patterned on a circuit side of the substrate. A process chamber having a wall with a plasma source adjacent to the wall of the process chamber is provided. The plasma source can be a high density plasma source. A vacuum pump in fluid communication with the process chamber and a gas inlet in fluid communication with the process chamber can be provided. A work piece support within the process chamber is provided. A work piece is formed by placing the substrate on a carrier support. The work piece can be formed by adhering the substrate to a support film and then mounting the substrate with the support film to a frame. The support film can have a polymer layer and/or a conductive layer. The support film can be standard dicing tape. The frame can have a conductive layer and/or a metal layer. The work piece is then loaded onto the work piece support for plasma processing. An RF power source can be coupled to the work piece support to create a plasma around the work piece. A tensional force is applied to the support film. The tensional force can be applied to the frame. The tensional force can be a mechanical force, a magnetic force and/or an electrical force. The support film can be elastically deformed by the tensional force. The support film cannot be plastically deformed by the tensional force. A heat transfer fluid can be introduced between the support film and the work piece. The heat transfer fluid can be a gas such as helium. The fluid pressure can be greater than one Torr and can be less than thirty Torr. An electrostatic or mechanical chuck can be incorporated into the work piece support whereby the chuck can clamp the support film to the chuck. The clamping of the work piece can be performed after the tensional force is applied to the support film. The tensional force that is applied to the support film can be changed after the support film is clamped. The tensional force that is applied to the support film can be removed after the support film is clamped. The pressure within the process chamber can be reduced through the vacuum pump and a process gas can be introduced into the process chamber through the gas inlet. A plasma is generated through the plasma source whereby the work piece is etched through the generated plasma. A vacuum compatible transfer module can be provided that communicates with the process chamber. The work piece can be loaded onto a transfer arm in the vacuum compatible transfer module whereby the process chamber is maintained under vacuum during a transfer of the work piece from the vacuum compatible transfer module to the process chamber. Yet another object of the present invention is to provide a method for plasma dicing a substrate. The substrate can have a semiconducting layer such as Silicon and/or the substrate can have a III-V layer such as GaAs. The substrate can have a protective layer such as a photoresist layer that is patterned on a circuit side of the substrate. A process chamber having a wall with a plasma source adjacent to the wall of the process chamber is provided. The plasma source can be a high density plasma source. A vacuum pump in fluid communication with the process chamber and a gas inlet in fluid communication with the process chamber can be provided. A work piece support within the process chamber is provided. A work piece is formed by placing the substrate on a carrier support. The work piece can be formed by adhering the substrate to a support film and then mounting the substrate with the support film to a frame. The support film can have a polymer layer and/or a conductive layer. The support film can be standard dicing tape. The frame can have a conductive layer and/or a metal layer. The work piece is then loaded onto the work piece support for plasma processing. An RF power source can be coupled to the work piece support to create a plasma around the work piece. The frame is positioned non-coplanar to the substrate on the work piece support. The support film can contact a first surface of the substrate. The support film can contact a second surface of the frame. The substrate can be positioned above the frame during the positioning step. The first surface of the substrate can be positioned non-coplanar to the second surface of the frame during the positioning step. The first surface of the substrate can be positioned above the second surface of the frame. The substrate can be supported by the work piece support and the frame can be supported by the work piece support. The substrate can be supported by the clamp and the frame can be supported by a process kit. The substrate can be supported by a clamp and the frame can be supported by a lift mechanism. The support film can be supported by the work piece support and the frame can be unsupported. An inner diameter of the frame can be greater than an outer diameter of the work piece support. The support film can be supported by the work piece support and the frame can be supported by a lift mechanism. The clamp can be an electrostatic chuck or a mechanical chuck which can be incorporated into the work piece support. The pressure within the process chamber can be reduced through the vacuum pump and a process gas can be introduced into the process chamber through the gas inlet. A plasma is generated through the plasma source whereby the work piece is etched through the generated plasma. A vacuum compatible transfer module can be provided that communicates with the process chamber. The work piece can be loaded onto a transfer arm in the vacuum compatible transfer module whereby the process chamber is maintained under vacuum during a transfer of the work piece from the vacuum compatible transfer module to the process chamber. Still yet another object of the present invention is to provide a method for plasma dicing a substrate. The substrate can have a semiconducting layer such as Silicon and/or the substrate can have a III-V layer such as GaAs. The substrate can have a protective layer such as a photoresist layer that is patterned on a circuit side of the substrate. A process chamber having a wall with a plasma source adjacent to the wall of the process chamber is provided. The plasma source can be a high density plasma source. A vacuum pump in fluid communication with the process chamber and a gas inlet in fluid communication with the process chamber can be provided. A work piece support within the process chamber is provided. A work piece is formed by placing the substrate on a carrier support. The work piece can be formed by adhering the substrate to a support film and then mounting the substrate with the support film to a frame. The support film can have a polymer layer and/or a conductive layer. The support film can be standard dicing tape. The frame can have a conductive layer and/or a metal layer. The work piece is then loaded onto the work piece support for plasma processing. An RF power source can be coupled to the work piece support to create a plasma around the work piece. A tensional force is applied to the support film. The tensional force can be applied to the frame. The tensional force can be a mechanical force, a magnetic force and/or an electrical force. The support film can be elastically deformed by the tensional force. The support film cannot be plastically deformed by the tensional force. A heat transfer fluid can be introduced between the support film and the work piece. The heat transfer fluid can be a gas such as helium. The fluid pressure can be greater than one Torr and can be less than thirty Torr. The pressure within the process chamber can be reduced through the vacuum pump and a process gas can be introduced into the process chamber through the gas inlet. A plasma is generated through the plasma source whereby the work piece is etched through the generated plasma. A vacuum compatible transfer module can be provided that communicates with the process chamber. The work piece can be loaded onto a transfer arm in the vacuum compatible transfer module whereby the process chamber is maintained under vacuum during a transfer of the work piece from the vacuum compatible transfer module to the process chamber. Another object of the present invention is to provide a method for plasma dicing a plurality of substrates. The plurality of substrates can have a semiconducting layer such as Silicon and/or the substrates can have a III-V layer such as GaAs. The plurality of substrates can have a protective layer such as a photoresist layer that is patterned on a circuit side of the substrate. A process chamber having a wall with a plasma source adjacent to the wall of the process chamber is provided. The plasma source can be a high density plasma source. A vacuum pump in fluid communication with the process chamber and a gas inlet in fluid communication with the process chamber can be provided. A work piece support within the process chamber is provided. A work piece is formed by placing the plurality of substrates on a carrier support. The work piece can be formed by adhering the plurality of substrates to a support film and then mounting the plurality of substrates with the support film to a frame. The support film can have a polymer layer and/or a conductive layer. The support film can be standard dicing tape. The frame can have a conductive layer and/or a metal layer. The work piece is then loaded onto the work piece support for plasma processing. An RF power source can be coupled to the work piece support to create a plasma around the work piece. A tensional force can be applied to the support film. The tensional force can be applied to the frame. The tensional force can be a mechanical force, a magnetic force and/or an electrical force. The support film can be elastically deformed by the tensional force. The support film cannot be plastically deformed by the tensional force. A heat transfer fluid can be introduced between the support film and the work piece. The heat transfer fluid can be a gas such as helium. The fluid pressure can be greater than one Torr and can be less than thirty Torr. An electrostatic or mechanical chuck can be incorporated into the work piece support whereby the chuck can clamp the support film to the chuck. The clamping of the work piece can be performed after the tensional force is applied to the support film. The tensional force that is applied to the support film can be changed after the support film is clamped. The tensional force that is applied to the support film can be removed after the support film is clamped. The pressure within the process chamber can be reduced through the vacuum pump and a process gas can be introduced into the process chamber through the gas inlet. A plasma is generated through the plasma source whereby the work piece is etched through the generated plasma. A vacuum compatible transfer module can be provided that communicates with the process chamber. The work piece can be loaded onto a transfer arm in the vacuum compatible transfer module whereby the process chamber is maintained under vacuum during a transfer of the work piece from the vacuum compatible transfer module to the process chamber. The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top down view of a semiconductor substrate illustrating individual devices separated by streets; FIG. 2 is a cross-sectional view of a semiconductor substrate illustrating individual devices separated by streets; FIG. 3 is a cross-sectional view of a semiconductor substrate mounted to tape and a frame; FIG. 4 is a cross-sectional view of a semiconductor substrate mounted to tape and a frame being etched by a plasma process; FIG. 5 is a cross-sectional view of separated semiconductor devices mounted to tape and a frame; FIG. 6 is a cross-sectional view of a vacuum processing chamber; FIG. 7 is a cross-sectional of a wafer/frame in process position; FIG. 8 is an enlarged cross-sectional view of a frame and a cover ring in a vacuum processing chamber; FIG. 9 is a cross-sectional view of a section of the inside the chamber with the cover ring mounted to a chamber wall; FIG. 10 is a cross-sectional view of a section of the inside the chamber with the cover ring mounted to an internal heat sink; FIG. 11 is a top down view of a semiconductor substrate mounted to tape and a frame supported by a transfer arm; FIG. 12 is a cross-sectional view of a semiconductor substrate mounted to tape and a frame supported by a transfer arm; FIG. 13 is a cross-sectional view of a wafer/frame in a transfer position; FIG. 14 is a top view of a screen; FIG. 15 is a cross-sectional view of an electrostatic chuck; FIG. 16 is a schematic view of a chamber in a transfer position; FIG. 17 is a cross sectional view of the work piece and work piece support; FIG. 18 is a cross sectional view of the work piece and work piece support; FIG. 19 is a cross sectional view of the work piece and work piece support; FIG. 20 is a cross sectional view of the work piece and work piece support; and FIG. 21 is a top down view of multiple semiconductor substrates mounted to tape and a frame. Similar reference characters refer to similar parts throughout the several views of the drawings. DETAILED DESCRIPTION OF THE INVENTION A typical semiconductor substrate after device fabrication is illustrated in FIG. 1 . The substrate ( 1 ) has on its surface a number of areas containing device structures ( 2 ) separated by street areas ( 3 ) in which there are no structures which allows for separation of the device structures into individual die. Although silicon is commonly used as a substrate material, other materials chosen for their particular characteristics are frequently employed. Such substrate materials include gallium arsenide and other III-V materials or non-semi-conductor substrates on which has been deposited a semi-conducting layer. In the present invention, as is shown in a cross sectional view in FIG. 2 , the device structures ( 2 ) are then covered with a protective material ( 4 ) while the street areas ( 3 ) remain unprotected. This protective material ( 4 ) can be a photoresist, applied and patterned by well-known techniques. Some devices, as a final process step are coated with a protective dielectric layer such as silicon dioxide or PSG which is applied across the whole substrate. This can be selectively removed from the street areas ( 3 ) by patterning with photoresist and etching the dielectric material, as is well known in the industry. This leaves the device structures ( 2 ) protected by the dielectric material and the substrate ( 1 ) substantially unprotected in the street areas ( 3 ). Note that in some cases test features to check the wafer quality may be located in the street areas ( 3 ). Depending on the specific wafer fabrication process flow, these test features may or may not be protected during the wafer dicing process. Although the device pattern illustrated shows oblong die, this is not necessary, and the individual device structures ( 2 ) may be any other shape, such as hexagons, as best suits the optimum utilization of the substrate ( 1 ). It is important to note that while the previous example considers dielectric materials as the protective film, that the invention may be practiced with a wide range of protective films including semi-conductive and conductive protective films. Furthermore, the protective layer can consist of multiple materials. It is also important to note that some portion of the protective film may be an integral part of the final device structure. (e.g., a passivation dielectric, metal bonding pad, etc.) The substrate ( 1 ) may be thinned, typically by a grinding process, which reduces the substrate thickness to a few hundred microns to as thin as approximately 30 microns or less. As is shown in FIG. 3 , the thinned substrate ( 1 ) is then adhered to a tape ( 5 ) which in turn is mounted in a rigid frame ( 6 ) to form a work piece ( 1 A). The tape ( 5 ) is typically made from a carbon-containing polymer material, and may additionally have a thin conductive layer applied to its surface. The tape ( 5 ) provides support for the thinned substrate ( 1 ) which is otherwise too fragile to handle without breakage. It should be noted that the sequence of patterning, thinning and then mounting is not critical and the steps may be adjusted to best fit the particular devices and substrate and the processing equipment used. It is important to note that while the previous example considers a work piece ( 1 A) that is comprised of mounting a substrate ( 1 ) on an adhesive tape ( 5 ) which in turn is attached to a frame ( 6 ), that the invention is not limited by the configuration of the wafer and carrier. The wafer carrier can be comprised a variety of materials. The carrier supports the substrate during the plasma dicing process. Furthermore, the wafer need not be attached to the carrier using an adhesive—any method that holds the wafer to the carrier and allows a means thermal communication of the substrate to the cathode is sufficient. (e.g. an electrostatically clamped carrier, a carrier with a mechanical clamping mechanism, etc.) While the example above describes mounting a single substrate ( 1 ) on adhesive tape ( 5 ) that is supported by a frame ( 6 ) to form a work piece ( 1 A), the invention can also be beneficially applied to a work piece ( 1 A) that is comprised of more than one substrate ( 1 ) mounted on adhesive tape ( 5 ) which is supported by a frame ( 6 ) as is shown in FIG. 21 . The substrates ( 1 ) can be different sizes, shapes, thicknesses and/or materials. It is preferable that if the substrates are different materials that they etch in similar etch chemistries (e.g. Ge and Si both etch in fluorine-based chemistries). The substrates ( 1 ) may have different areas of exposed materials and/or different patterns. Some of the substrates ( 1 ) may be pieces of larger substrates. It is preferred that the substrates ( 1 ) be located inside the inner diameter of the support frame ( 6 ). In one embodiment, the outer diameter of the support frame ( 6 ) is smaller than the outer diameter of the work piece support. After mounting the substrate ( 1 ) with the tape ( 5 ) in the dicing frame ( 6 ), the work piece ( 1 A) is transferred into a vacuum processing chamber. Ideally, the transfer module is also under vacuum which allows the process chamber to remain at vacuum during transfer, reducing processing time and preventing exposure of the process chamber to atmosphere and possible contamination. As shown in FIG. 6 , the vacuum processing chamber ( 10 ) is equipped with a gas inlet ( 11 ), a high density plasma source ( 12 ) to generate a high density plasma, such as an Inductively Coupled Plasma (ICP), a work piece support ( 13 ) to support the work piece ( 1 A), an RF power source ( 14 ) to couple RF power to the work piece ( 1 A) through the work piece support ( 13 ) and a vacuum pump ( 15 ) for pumping gas from the processing chamber ( 10 ). During processing, the unprotected areas of substrate ( 1 ) are etched away using a reactive plasma etch process ( 7 ) as shown in FIG. 4 . This leaves the devices ( 2 ) separated into individual die ( 8 ) as shown in FIG. 5 . In another embodiment of the invention, the unprotected areas of the substrate ( 1 ) are partially etched away using a reactive plasma etch process ( 7 ). In this case, a downstream operation, such as a mechanical breaking operation, can be used to complete the die separation. These downstream methods are well known in the art. While the previous example describes the invention using a vacuum chamber in conjunction with a high density plasma, it is also possible to etch the unprotected areas of the substrate using a wide range of plasma processes. For example, one skilled in the art can imagine variations of the invention using a low density plasma source in a vacuum chamber or even the use of plasmas at or near atmospheric pressures. When the substrate/tape/frame assembly ( 1 A) is in the position for plasma processing, it is important that the frame ( 6 ) is protected from exposure to the plasma ( 7 ). Exposure to the plasma ( 7 ) will cause heating of the frame ( 6 ) which in turn will cause local heating of the mounting tape ( 5 ). At temperatures above approximately 100° C., the physical properties of the tape ( 5 ) and its adhesive capability may deteriorate and it will no longer adhere to the frame ( 6 ). Additionally, exposure of the frame ( 6 ) to the reactive plasma gas may cause degradation of the frame ( 6 ). Since the frame ( 6 ) is typically re-used after wafer dicing, this may limit the useful lifetime of a frame ( 6 ). Exposure of the frame ( 6 ) to the plasma ( 7 ) may also adversely affect the etch process: for example the frame material may react with the process gas, effectively reducing its concentration in the plasma which will reduce the etch rate of the substrate material, thus increasing process time. To protect the frame ( 6 ), a protective cover ring ( 20 ), as shown in FIGS. 6, 7 and 8 , is positioned above the frame ( 6 ). The cover ring ( 20 ) does not touch the frame ( 6 ) since contact with the frame ( 6 ) (which would occur during transfer into the process chamber ( 10 )) can generate undesirable particles. In FIG. 8 , dimension (A) represents the distance between the cover ring ( 20 ) and the frame ( 6 ). This dimension can range from less than approximately 0.5 mm to greater than approximately 5 mm with an optimal value of 1.5 mm. If the distance (A) is too large, plasma ( 7 ) will contact the frame ( 6 ) and the benefits of the cover ring ( 20 ) will be lost. It is important that the cover ring ( 20 ) is temperature controlled, otherwise its temperature will increase due to exposure to the plasma ( 7 ) and in turn heat the tape ( 5 ) and the frame ( 6 ) via radiational heating, causing degradation as noted above. For the case where the cover ring ( 20 ) is cooled, cooling of the cover ring ( 20 ) is accomplished by having it in direct contact with a cooled body, such as the process chamber wall ( 10 W) shown in FIG. 9 or a heat sink ( 30 ) located within the process chamber ( 10 ) shown in FIG. 10 . To ensure that heat is adequately removed from the cover ring ( 20 ) to the heat sink ( 30 ), the cover ring ( 20 ) should be made of a material that has good thermal conductivity. Such materials include many metals, for example Aluminum, but other thermally conductive materials, such as Aluminum Nitride and other ceramics can be used. The choice of the cover ring material is chosen to be compatible with the plasma process gases used. While Aluminum is satisfactory for Fluorine based processes, an alternate material, such as Aluminum Nitride, or the addition of a protective coating, such as Aluminum Oxide may be necessary when Chlorine based processes are used. Operation temperature of the cover ring ( 20 ) during plasma processing is typically less than 80° C. which minimizes heat radiation to the tape ( 5 ) and the frame ( 6 ) and ensures that the tape ( 5 ) maintains its mechanical integrity. Alternatively, the cover ring ( 20 ) may be temperature controlled by bringing the cover ring ( 20 ) into contact with a temperature controlled fluid. This fluid can be a liquid or gas. In the case where the cover ring ( 20 ) temperature is controlled by a fluid, the cover ring ( 20 ) may contain a number of fluid channels to facilitate heat transfer. These fluid channels can be internal to the cover ring ( 20 ), externally attached, or some combination of the two. In one instance, the cover ring ( 20 ) can extend from the substrate diameter to the inner chamber diameter continuously. To avoid a loss in pumping conductance, which can adversely affect pressure control within the process chamber ( 10 ), a plurality of holes ( 21 ) can be added to the cover ring ( 20 ) which allows sufficient conductance of the process gas while still providing a path for heat removal from the cover ring ( 20 ). In FIGS. 9 and 10 , a plurality of holes ( 21 ) arranged in a specific geometry is shown, but the density, size, pattern and symmetry of the holes ( 21 ) can vary depending on the process chamber ( 10 ) dimensions and the pumping conductance required. The substrate/tape/frame assembly ( 1 A) is transferred both into and out of the process chamber ( 10 ) by a transfer arm ( 40 ) that supports the frame ( 6 ) and substrate ( 1 ) so that they are maintained coplanar as shown in FIGS. 11 and 12 . The transfer arm ( 40 ) may support both the tape ( 5 ) and the frame ( 6 ) or the frame ( 6 ) alone, but it is important that the assembly ( 1 A) not be supported beneath the substrate ( 1 ) area alone because of the fragile nature of thinned substrates ( 1 ). The transfer arm ( 40 ) has an alignment fixture ( 41 ) attached to it that aligns the frame ( 6 ) in a repeatable position before being transferred into the process chamber ( 10 ). The frame ( 6 ) can also be aligned by other techniques well-known in semiconductor processing (e.g., optical alignment). The alignment can also be performed on the substrate ( 1 ) by such well-known techniques. It is important that the substrate/tape/frame assembly ( 1 A) be aligned before placement within the process chamber ( 10 ) to avoid mis-processing as explained below. In FIG. 8 , the dimension (D) represents the distance between the outer diameter of the substrate ( 1 ) and the inner diameter of the frame ( 6 ). This may be 20 mm to 30 mm (e.g., Disco Corporation dicing frame is 250 mm for 200 mm substrates, so that the dimension (D) is nominally 25 mm). During mounting of the wafer ( 1 ) on the tape ( 5 ) within the frame ( 6 ), the deviation of wafer ( 1 ) placement may be as much as 2 mm so that dimension (E), which is the distance between the substrate ( 1 ) outer diameter and the inner diameter of the cover ring ( 20 ) can also vary from assembly to assembly by up to 2 mm. If at some point (E) is less than zero the cover ring ( 20 ) will overlay the edge of the substrate ( 1 ). This point will be shadowed and prevented from etching, which can prevent die separation and cause problems in subsequent processing steps. Alignment of the substrate/tape/frame assembly ( 1 A) prior to transfer is required to prevent such problems. Further, to additionally ensure that dimension (E) is not less than zero, the cover ring inner diameter should be greater than the diameter of the substrate ( 1 ) with a preferred diameter 5 mm greater than the substrate (e.g., 205 mm cover ring inner diameter for 200 mm substrate). Dimension (F) in FIG. 8 represents the distance from the inner diameter of the cover ring ( 20 ) to the inner diameter of the frame ( 6 ). Alignment of the frame ( 6 ) prior to transfer into the process chamber ( 10 ) ensures that (F) remains constant for the entire circumference around the substrate ( 1 ) and that any portion of tape ( 5 ) that is not contacted by the Electrostatic chuck (ESC) ( 16 ) is shadowed from the plasma ( 7 ). When the substrate/tape/frame assembly ( 1 A) is transferred into the process chamber ( 10 ), it is placed onto the lifting mechanism ( 17 ) and removed from the transfer arm ( 40 ). The reverse process occurs during transfer of the substrate/tape/frame assembly ( 1 A) out of the process chamber ( 10 ). The lifting mechanism ( 17 ) touches the frame ( 6 ) area and provides no point contact to the substrate ( 1 ). Point contact to the substrate ( 1 ) can cause damage to the substrate ( 1 ), particularly after die separation and unloading of the substrate/tape/frame assembly ( 1 A), since the flexibility of the tape ( 5 ) would cause the die to contact each other and damage to occur. FIG. 13 shows the lifting mechanism ( 17 ) contacting the frame ( 6 ) from the underside: however the frame ( 6 ) can also be removed from the transfer arm ( 40 ) by contact with the top surface or outer diameter using a clamping device. To process the substrate ( 1 ), the frame ( 6 ), the work piece support ( 13 ), and the cover ring ( 20 ) move relative to each other. This can be accomplished by moving either the cover ring ( 20 ), the work piece support ( 13 ), or the lifting mechanism ( 17 ) or any combination of the three. While the tape ( 5 ) in the work piece ( 1 A) is typically under some tension—there are often imperfections (ripples, etc.) in the tape that can make it difficult to clamp the work piece ( 1 A) to the substrate support ( 13 A) sufficiently for effective helium backside cooling. In order to facilitate clamping of the work piece ( 1 A) to the work piece support ( 13 ) it is beneficial to construct the work piece support assembly ( 13 A) such that the flexible tape ( 5 ) is placed under additional tension while the clamping force is applied to the work piece ( 1 A). Preferably, the additional tension is applied to the tape ( 5 ) before the clamping force is applied. Once the tape ( 5 ) has been clamped, the additional tensioning force may be changed or removed. One way in which this additional tensioning may be accomplished to configure the work piece support assembly ( 13 A) such that the surface defined by the frame/tape interface ( 50 as shown in FIG. 17 ) is located at or below the surface defined by the substrate/tape interface ( 55 as shown in FIG. 17 ). It is preferred that the some portion of the surface 50 is at least approximately 0.1 mm below some portion of the surface 55 . Some portion of the surface 50 can be at least approximately 1 mm below the surface 55 . In another embodiment, all of the surface 50 is below the surface 55 . In this embodiment, it is preferred that the surface 50 is at least approximately 0.1 mm below the surface 55 . The surface 50 can be at least approximately 1 mm below the surface 55 . In the case where the tape ( 5 ) is adhered to both the bottom surface of the substrate ( 1 ) and the bottom surface of the frame ( 6 ) this may be accomplished by ensuring that the top surface of the electrostatic chuck ( 16 ) is located at or preferably above the plane defined by the lower surface of the bottom of the frame ( 6 ) as shown in FIG. 17 . In this configuration, it is preferred that the top surface of the ESC is at least 0.1 mm above the bottom surface of the bottom of the frame ( 16 ). The work piece ( 1 A) may remain in this configuration during plasma processing or the additional tension may be changed at some point in the process. This configuration is particularly beneficial when the clamping force is applied by an electrostatic chuck. The additional tensioning may be applied through a number of hardware configurations. Note that while FIG. 17 shows the tape ( 5 ) being attached to the bottom of the support frame ( 6 ) that the method may still be beneficially applied to configurations where the tape ( 5 ) is applied to the top surface of the frame ( 6 ). The force required to apply the additional tension to the tape ( 5 ) may be applied to the frame ( 6 ). The force may be applied to the top of the frame, the bottom of the frame or both. Some portion of the force required to apply the additional tension to the tape may be derived from the weight of the frame ( 6 ). In one configuration, the tape frame ( 6 ) is supported by the lift mechanism ( 17 ) during clamping. The top surface of the process kit ( 18 ) will be at or below the plane of the top surface of the electrostatic chuck ( 16 ). The process kit may be in contact with the tape ( 5 ) and/or the frame ( 6 ). In the cases where the process kit is not in contact with the work piece, it is preferred that the gap between the work piece ( 1 A) and the process kit ( 18 ) is less than approximately 5 mm in order to prevent plasma formation in the space between the work piece ( 1 A) and the process kit ( 18 ). In an alternate configuration, the tape frame is not supported by the lift mechanism ( 17 ) in order to tension the tape. In this configuration the frame ( 6 ) may be supported by the process kit ( 18 ), and/or a frame support member ( 17 A) as shown in FIG. 18 . In yet another alternate configuration, the process kit may be incorporated into and/or replaced by extending the electrostatic chuck as shown in FIG. 19 . The tape frame ( 6 ) may be supported by the electrostatic chuck where the ESC surface supporting the substrate ( 1 ) is higher than the surface supporting the tape frame ( 6 ) placing the tape ( 5 ) under additional tension. In a preferred embodiment, a portion of the surface supporting the substrate ( 1 ) is at least 0.1 mm higher than the surface supporting the tape frame ( 6 ). In yet another configuration, the inner diameter of the tape frame ( 6 ) is larger than the outer diameter of the work piece assembly ( 13 A). In this configuration the frame may be held by the lift mechanism ( 17 ) and/or an external tape frame support ( 17 A). Alternatively, the frame may be unsupported such that the weight of the frame contributes to the tensioning force. While the examples above describe tensioning the tape in conjunction with an electrostatic clamp, the invention may also be beneficially applied to other clamping configurations, including mechanical clamping. In another embodiment the invention may also be beneficially applied to a work piece support assembly that does not utilize a clamping mechanism. FIG. 20 shows yet another configuration. In this configuration the flexible tape ( 5 ) is stretched across the top surface of the work piece support ( 13 A) in order to form a seal between the tape ( 5 ) and the work piece support ( 13 A). A heat transfer fluid, typically helium gas is introduced between the tape ( 5 ) and the work piece support ( 13 A). The seal between the tape ( 5 ) and the work piece support ( 13 A) needs to be sufficient to support a heat transfer fluid pressure of greater than approximately 1 Torr but less than approximately 30 Torr between the tape ( 5 ) and the work piece support ( 13 A). It is preferable that the gas pressure behind the tape does not cause a separation between the tape ( 5 ) and the work piece support ( 13 A) greater than approximately 100 microns as this would adversely affect the heat transfer between the substrate and the work piece support. It is desired that the areas of tape under the substrate ( 1 ) and tape areas of the tape that are exposed to the plasma be inside the seal created between the wafer support assembly ( 13 A) and the tape ( 5 ). The force applied to the tape frame will put at least a portion of the tape ( 5 ) under tension—possibly deforming the tape ( 5 ). It is important to limit the applied force to the tape ( 5 ) such that the tape deformation does not preclude downstream packaging operations. Ideally, tensioning the tape ( 5 ) will result in only elastic deformation—though some amount of plastic deformation may be permissible provided it does not negatively impact downstream operations. The force required to create the seal between the tape ( 5 ) and the work piece support ( 13 A) may be applied to the tape frame ( 6 ). The force can be magnetic, mechanical, electrostatic, or some combination of the three. The force may be applied to the top of the frame, the bottom of the frame or both. Alternatively, the force can be applied directly to the tape, preferably in the areas not overlapping the substrate ( 1 ) or the frame ( 6 ). In yet another embodiment, an electrostatic force may be applied to the tape underneath the area covered by the substrate ( 1 ) in order to minimize the gap between the tape ( 5 ) and the work piece support ( 13 A). During plasma processing, heat is transferred to all of the surfaces the plasma ( 7 ) touches including the substrate ( 1 ), tape ( 5 ), and frame ( 6 ). The cover ring ( 20 ) will minimize the heat transfer to areas of the tape ( 5 ) and the frame ( 6 ), but the substrate ( 1 ) must remain exposed to the plasma ( 7 ) for processing. As shown in FIG. 6 , a conductive screen ( 25 ) (e.g., made from aluminum or aluminum coated with an appropriate plasma resistant coating) can be placed between the substrate ( 1 ) and the plasma ( 7 ). This will reduce ion bombardment on the substrate ( 1 ) and thus reduce heating of the substrate ( 1 ). FIG. 14 shows the screen ( 25 ) is provided with a plurality of holes ( 26 ) which still allows neutral species from the plasma ( 7 ) to reach the substrate ( 1 ) such that the etch rate is only slightly reduced. Holes ( 27 ) allow for mounting of the screen ( 25 ) to the processing chamber ( 10 ). Additional cooling of the substrate ( 1 ) is provided by the use of an Electrostatic chuck (ESC) ( 16 ). Such ESCs ( 16 ) are commonly used in semiconductor processing to apply downward force to the substrate ( 1 ) while a pressurized gas such as Helium is maintained between the substrate ( 1 ) and the electrode. This ensures that heat transfer can occur between the substrate ( 1 ) and the electrode, which is cooled. Typically, ESCs ( 16 ) are the same diameter or smaller than the substrate ( 1 ) to prevent unwanted exposure of the ESC ( 16 ) surface to potentially corrosive plasma gases that can decrease the lifetime of the ESC ( 16 ). With a substrate/tape/frame assembly ( 1 A), the area outside the diameter of the substrate ( 1 ) is tape ( 5 ). Using a typical ESC ( 16 ), because the cover ring ( 20 ) is larger than the diameter of the substrate ( 1 ), there would be an area of tape ( 5 ) exposed to the plasma process that is not being clamped and cooled by the ESC ( 16 ) or being shielded from the plasma ( 7 ) by the cover ring ( 20 ). Such an area of tape ( 5 ) would reach a high temperature and possibly fail. Thus, FIG. 8 shows the use of an ESC ( 16 ) that is made purposely larger than the substrate diameter so that any tape ( 5 ) which is exposed to the plasma in region (E) is also clamped and cooled. This diameter can be extended outwards to the outer diameter of the frame ( 6 ), but is preferred to be 2 mm less than the inner diameter of the frame ( 6 ). In the case where the work piece ( 1 A) contains more than one substrate ( 1 ), it is preferred that the ESC ( 16 ) extends beyond the edge of at least one substrate ( 1 )—preferably extending beyond the edges of all substrates ( 1 ). In order to confine the cooling gas (typically helium) behind the substrates the tape ( 5 ) must form a sealing surface between the work piece support ( 1 A) and the tape ( 5 ). This sealing surface is often called a seal band. The seal band is typically slightly higher than some portion of the area of the ESC that it circumscribes. In one embodiment the sealing surface is continuous and forms a shape that circumscribes all the substrates ( 1 ). In an another embodiment, the sealing surface may be discontinuous and circumscribes at least one region. It is preferred that a portion of the sealing band overlays a portion of ESC clamping electrode(s). In a preferred embodiment, all of the sealing band overlays a clamping electrode. The substrates ( 1 ) may overlay the sealing band(s) or alternatively, the sealing band(s) may lie outside the substrate(s) ( 1 ) FIG. 8 shows a filler ring ( 18 ) that extends from the outer diameter of the ESC ( 16 ) to the lifting mechanism ( 17 ). This filler ring ( 18 ) is used to prevent the back surface of any exposed tape ( 5 ) from being contacted by the plasma ( 7 ). Although a separate filler ring ( 18 ) is shown, an extension of the ESC ( 16 ) would also prevent plasma ( 7 ) exposure to the backside of the tape ( 5 ). The filler ring ( 18 ) is typically made of a dielectric material, such as a ceramic (e.g., Aluminum Oxide) or a plastic material, (e.g., polytetrafluoroethylene (PTFE, Teflon)) selected for both its low thermal conductivity and its low electrical conductivity. Typical ESCs ( 16 ) used in semiconductor processing have a pattern of shallow features fabricated on their surface to facilitate Helium distribution or to minimize contact with the backside of a substrate ( 1 ) to reduce particle formation. Such an ESC ( 16 ) can be used for plasma dicing when a substrate ( 1 ) is separated into multiple die, providing the feature dimensions on the ESC surface are smaller than the die size. When the die size approaches and becomes smaller than the ESC feature size, the tape will now conform to the features and flex, possibly causing the die to touch each other which can cause damage. The use of a substantially coplanar ESC surface eliminates this problem. Note that though the preceding example describes an ESC that cools the substrate, for some materials (e.g. approximately 180° C. for indium containing substrates) that require a higher temperature to facilitate the plasma etch process, a higher temperature controlled ESC ( 16 ) temperature may be desirable. A typical ESC ( 16 ) (coulombic design of FIG. 15 ) consists of one or more electrodes ( 33 ) to which a high voltage ( 19 ) is applied, separated from the work piece support ( 13 ) by a thick insulating layer ( 32 ) and separated from the material to be clamped by a thin layer of dielectric material ( 34 ). The clamping force generated by electrostatic forces increases as the thickness of this dielectric layer ( 34 ) decreases and increases as the voltage applied increases. In the present instance, when the substrate ( 1 ) is mounted on an insulating tape ( 5 ), the thickness of the tape ( 5 ) adds to the total dielectric thickness interposed between the electrode ( 33 ) and the substrate ( 1 ). This total thickness should not be determined primarily by the tape thickness, since this is likely to vary, resulting in a variable clamping performance. Rather the ESC dielectric ( 34 ) should be relatively thick (of the order of a few 100 microns) to maintain a clamping performance independent of tape thickness. A high clamping force can be achieved by operating at a high clamping voltage (up to approximately 10 kV). During plasma processing, RF power ( 14 ) is coupled to the substrate ( 1 ) to control ion bombardment on the substrate ( 1 ) and control the etch characteristics. The frequency of this RF may vary from 100's of MHz down to a few hundred kHz. When etching a substrate material down to an insulating layer (in this instance the mounting tape), problems with the etch associated with charging of the insulating layer are well known. Such problems include localized severe undercutting at the substrate/insulator interface which is undesirable during die separation, since this affects the performance of the singulated die. As is well known in the art, such charging problems can be reduced by operating at low RF frequencies and additionally pulsing or modulating the RF power at low frequency. Since RF coupling at such low frequency is not efficient through a thick dielectric material ( 32 ), the RF coupling to the substrate ( 1 ) is preferably via the one or more ESC electrodes, for example via a coupling capacitor ( 35 ) rather than via the RF powered work piece support ( 13 ). To maintain uniform RF coupling to the substrate ( 1 ), the ESC electrode or electrodes should also be uniformly disposed behind the substrate ( 1 ). This is difficult to achieve if multiple electrodes are used, since the necessary gaps between the electrodes result in a local variation in the RF coupling which adversely affects the quality of the etch, particularly the undercutting at the substrate/tape interface. A preferred embodiment of the ESC design therefore incorporates a so called monopolar design, in which a single electrode is used to provide the clamping force. Additionally, there should be as few as possible penetrations through this electrode (for example as for pin lifts) since these penetrations will also disturb the RF coupling and degrade the etch performance. The substrate can be processed using techniques well known in the semiconductor industry. Silicon substrates are generally processed using a Fluorine based chemistry such as SF 6 . SF 6 /O 2 chemistry is commonly used to etch Silicon because of its high rate and anisotropic profile. A disadvantage of this chemistry is its relatively low selectivity to masking material for example to photoresist which is 15-20:1. Alternatively a Timed Division Multiplex (TDM) process can be used which alternates between deposition and etching to produce highly anisotropic deep profiles. For example, an alternating process to etch Silicon uses a C 4 F 8 step to deposit polymer on all exposed surfaces of the Silicon substrate (i.e., mask surface, etch sidewalls and etch floor) and then an SF 6 step is used to selectively remove the polymer from the etch floor and then isotropically etch a small amount of silicon. The steps repeat until terminated. Such a TDM process can produce anisotropic features deep into Silicon with selectivities to the masking layer of greater than 200:1. This then makes a TDM process the desired approach for plasma separation of Silicon substrates. Note that the invention is not limited to the use of fluorine containing chemistries or a time division multiplex (TDM) process. For example, silicon substrates may also be etched with Cl, HBr or I containing chemistries as is known in the art. For III-V substrates such as GaAs, a Chlorine based chemistry is extensively used in the semiconductor industry. In the fabrication of RF-wireless devices, thinned GaAs substrates are mounted with the device side down onto a carrier, where they are then thinned and patterned with photoresist. The GaAs is etched away to expose electrical contacts to the front side circuitry. This well-known process can also be used to separate the devices by the front side processing described in the above mentioned invention. Other semiconductor substrates and appropriate plasma processes can also be used for the separation of die in the above mentioned invention. To further reduce the problems associated with charging at the substrate/tape interface, the process can be changed at the point at which the interface is exposed to a second process which has less tendency to undercut and is typically a lower etch rate process. The point in time at which the change takes place depends upon the substrate thickness, which is likely to vary. To compensate for this variability, the time at which the substrate/tape interface is reached is detected using an endpoint technique. Optical techniques which monitor the plasma emission are commonly used to detect endpoint and U.S. Pat. Nos. 6,982,175 and 7,101,805 describe such an endpoint technique which is appropriate to a TDM process. After singulation of the semiconductor substrate there can be unwanted residues that exist on the devices. Aluminum is commonly used as an electrical contact for semiconductor devices and when exposed to Fluorine based plasmas a layer of AlF 3 is formed on its surface. AlF 3 is nonvolatile under normal plasma processing conditions and is not pumped away from the substrate and out of the system and remains on the surface after processing. AlF 3 on Aluminum is a common cause of failure for devices because the bonding strength of wires to the electrical contacts is greatly reduced. Thus the removal of the AlF 3 from the surface of the electrical contacts after plasma processing is important. Wet methods can be used; however, this becomes difficult because of the fragile nature of the separated die, and the possible damage to the tape causing die release. Therefore, the process can be changed to a third process while the substrate is still within the vacuum chamber, to a process designed to remove any AlF 3 formed. U.S. Pat. No. 7,150,796 describes a method for in-situ removal of AlF 3 using an Hydrogen based plasma. Likewise, an in-situ treatment can be used to remove other halogen-containing residues when other halogen-containing gases are used to etch the substrate. While the above examples discuss the use of plasma for separating die (dicing), aspects of the invention may be useful for related applications such as substrate thinning, plasma ashing, and bond pad cleaning. The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention. Now that the invention has been described,

The present invention provides a method for plasma dicing a substrate, the method comprising providing a process chamber having a wall; providing a plasma source adjacent to the wall of the process chamber; providing a work piece support within the process chamber; placing a work piece onto the work piece support, said work piece having a support film, a frame and the substrate; loading the work piece onto the work piece support; applying a tensional force to the support film; clamping the work piece to the work piece support; generating a plasma using the plasma source; and etching the work piece using the generated plasma.

BACKGROUND INFORMATION [0001] 1. Field [0002] Embodiments of the disclosure relate generally to the field of packaging for pastry and baked goods and more particularly to a multidiametric case for a cupcake or similar good, the case having a relieved upper portion for clearance of frosting or topping, an aperture in the bottom allowing easy removal of the cupcake from the package and retaining elements within the case for closely contacting the cupcake for retention in the package until removal. [0003] 2. Background [0004] Cupcakes and similar baked goods and pastries are typically packaged in boxes containing multiple units. Baked goods such as cupcakes are quite fragile in nature and such packaging does not provide satisfactory protection for the baked goods, allowing individual cupcakes to move within the box creating distortion or damage to the soft cake and frosting. Retaining elements within the multiunit box have been previously employed as disclosed in U.S. Pat. No. 6,003,671 issued to McDonnough et al on Dec. 21, 1999. However extracting individual cupcakes is typically not easy or convenient and such packaging is not readily economically adaptable for individual cupcakes. [0005] Individual packaging has been provided in the form of small boxes or paper wrapping which suffer many of the same issues as multiunit packaging. Certain single item packages such as that disclosed in US patent publication 2004/0251162 to McGinnis et al published on Dec. 16, 2004 have been provided, however, such packaging is overly complex and expensive to be cost effective for high quantity production and sale of baked goods. [0006] It is therefore desirable to provide a cost effective packaging system for individual cupcakes or similar baked goods. It is additionally desirable that such a packaging system would allow easy removal of the cupcake without damage while retaining the cupcake safely within the package until removal is desired. SUMMARY [0007] Exemplary embodiments provide cupcake package employing a base element having a primary diameter for receiving a cupcake body and a relieving cylinder having a second diameter extending from the base element for clearance of a top contour of the cupcake. A bottom surface closes the base element and includes an aperture centrally located therein sized to accept insertion of a finger for removal of the cupcake. A cylindrical lid is closely received over the relieving cylinder to close the package. In one exemplary embodiment the base element is frustoconical. [0008] In certain implementations, the base element further incorporates a restraint system for the cupcake. A first restraint system includes two sets of opposing apertures in the base element vertically displaced from and perpendicular to each other. A first dowel is received through the first set of apertures and extending through a cupcake body carried in the base element and a second dowel is received through the second set of apertures and extending through the cupcake body. [0009] A second restraint system incorporates multiple pyramidal protuberances extending from an inner surface of the base element oriented with an extended point downward toward the bottom to engage the body of the cupcake. [0010] A third restraint system uses one or more circular ridges extruded from an inner surface of the base element to engage the body of the cupcake. [0011] The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present invention or may be combined in yet other embodiments further details of which can be seen with reference to the following description and drawings BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1A is a bottom angle isometric view of a general embodiment of the cupcake package of the present invention; [0013] FIG. 1B is a side view of the embodiment of FIG. 1A ; [0014] FIG. 1C is a bottom view of the embodiment of FIG. 1A ; [0015] FIG. 1D is a top angle isometric view of the embodiment of FIG. 1A with the closure lid removed; [0016] FIG. 1E is a side section view of the embodiment of FIG. 1A with a cupcake inserted in the case; [0017] FIG. 1F is the side section view of the case with the cupcake being removed; [0018] FIG. 2A is a bottom angle isometric view of an embodiment of the cupcake package with a first restraint structure; [0019] FIG. 2B is a top angle isometric view of the embodiment of FIG. 2A ; [0020] FIG. 2C is a bottom view of the embodiment of FIG. 2A ; [0021] FIG. 2D is a top view of the embodiment of FIG. 2A showing interior details of the embodiment; [0022] FIG. 2E is a side section view of the embodiment of FIG. 2A ; [0023] FIG. 3A is a top isometric view of an embodiment of the cupcake package with a second restraint structure; [0024] FIG. 3B is a top view of the embodiment of FIG. 3A ; [0025] FIG. 3C is a side section view of the embodiment of FIG. 3A ; [0026] FIG. 4A is a top isometric view of an embodiment of the cupcake package with a third restraint structure; and, [0027] FIG. 4B is a side section view of the embodiment of FIG. 4A . DETAILED DESCRIPTION [0028] The embodiments described herein disclose a cupcake package having a multidiametric case with multiple cylindrical elements or a combination of cylinders and conical frustrums to receive the cupcake and having a bottom with an aperture for urging the cupcake from the case with a consumer's finger, a lid for closing the case, and various restraint elements within the case to maintain the cupcake in the case until removed. [0029] As shown in FIG. 1A-1E for an exemplary embodiment, a frustoconical base element 10 of the case with a first primary diameter 11 receives the body of the cupcake (as best seen in FIG. 1E ). The shape of the base element may be a conical frustrum as shown for use with a conventional cupcake or various depths and diameters of cylindrical elements or other rotated geometric shapes defined to closely receive the baked good. The inner surface 12 of the base element frictionally engages the sides of the cupcake to assist in retaining the cupcake in the package and prevent unwanted motion in the package during handling or transport. A cylindrical top element 14 expands from the base element 10 to a second diameter 15 to allow volumetric relief within the package for frosting or top contouring of the cupcake or other baked good to be contained in the case. Further, the larger diameter of the top element simplifies the insertion of the cupcake or baked good into the case. [0030] A lid 16 having an inner diameter sized to be closely received over the cylindrical top element 14 provides a closure for the case to protect the cupcake or baked good after insertion into the case. For the embodiment shown a filleted external surface of the lid allows for easy grasping by the consumer for removal. In alternative embodiments, a smooth cylindrical external surface or a textured surface may be employed. [0031] A bottom surface 18 of the base element 10 incorporates an aperture 20 which is sized to accommodate insertion of a fingertip. As best seen in FIG. 1F , after removing the lid, inserting a fingertip through aperture 20 and pressing upward against the bottom 22 of the cupcake urges the cupcake body 24 from the case allowing the consumer to easily remove the cupcake for consumption. [0032] For the exemplary embodiments, injection molded polystyrene or similar material may be employed for the case and lid providing a very low cost, mass producible product. Alternative paper, cardboard or plastic materials may be employed in alternative embodiments using standard fabrication techniques known to those skilled in the art. [0033] To further restrain the cupcake in the case, a restraint system is employed. As shown in FIGS. 2A-2E , a first exemplary restraint system for the embodiment shown incorporates apertures 30 in the base element through which wooden or plastic toothpicks or dowels 32 are inserted, piercing the body of the cupcake. The dowel ends extend through the apertures 30 on each side of the base element thereby restraining the cupcake within the case. For the embodiment shown, two perpendicular vertically offset sets of apertures and dowels are employed. In alternative embodiments, a single aperture set and dowel may be employed or additional sets for increased security. For removal of the cupcake, the dowels are extracted from the case and the cupcake is removed by inserting a finger into the aperture 20 in the bottom 18 to urge the cupcake out of the case. [0034] A second exemplary restraint system is shown in FIGS. 3A-3C which employs pyramidal protuberances 34 extending from the inner surface 12 of the base element 10 . Orientation of the protuberances with point 36 extending downwardly toward the bottom 18 of the base element engages and restrains the body of the cupcake when the cupcake is placed into the case and urged toward the bottom. For the embodiment shown, four pyramidal protuberances 34 are shown. In alternative embodiments one or more protuberances may be employed as required to firmly secure the cupcake or other backed good in the case. For removal of the cupcake, inserting a finger into the aperture 20 in the bottom 18 and urging the cupcake upwards with sufficient force overcomes the friction created by the indentation of the pyramidal protuberances in the body of the cupcake allowing it to be removed from the case. [0035] Ridges 38 extruded from the inner surface 12 of the base element 10 provide a third exemplary retention system for the embodiments disclosed as shown in FIGS. 4A and 4B . For the embodiment shown, the ridges extend around an entire circumference of the inner surface and two ridges are employed. In alternative embodiments ridges extending over a portion of the circumference or a single or additional multiples of ridges are employed. A substantially circular cross section of the ridges is employed which provides sufficient resistance against the body of the cupcake to retain the cupcake in the case. However, alternative cross sections such as triangular or rectangular may be employed in alternative embodiments. As with the pyramidal protrusions, removal of the cupcake is accomplished by inserting a finger into the aperture 20 in the bottom 18 and urging the cupcake upwards with sufficient force overcomes the friction created by the indentation of the circular ridges in the body of the cupcake allowing it to be removed from the case. [0036] Having now described various embodiments of the invention in detail as required by the patent statutes, those skilled in the art will recognize modifications and substitutions to the specific embodiments disclosed herein. Such modifications are within the scope and intent of the present invention as defined in the following claims.

A cupcake package includes a base element having a primary diameter for receiving a cupcake body and a relieving cylinder having a second diameter extending from the base element for clearance of a top contour of the cupcake. A bottom surface closes the base element and includes an aperture centrally located therein sized to accept insertion of a finger for removal of the cupcake. A cylindrical lid is closely received over the relieving cylinder to close the package.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to ecology, and more specifically to a System and method for saving the rainforests. [0003] 2. Background [0004] The destruction of the rainforests in the last decades has become the biggest crime against humanity and against nature and against other entire species of animals, and also the biggest irreversible folly of the late 20 th century and beginning of the 21 st . Various statistics show that at the current rate of destruction, unless drastic changes are made right now, by the year 2020, 90-100% of all the rainforests will be irrevocably destroyed, causing damages that will take MILLIONS OF YEARS to repair, if at all. Not only that such changes have not been made so far, but the rate of destruction continually increases. Apart from the destruction of our natural resources, we are also murdering entire species, and the land itself typically becomes desert wasteland with eroded soil, where almost nothing can be grown anymore. For example, according to http://www.mongabay.com/0801.htm, “Tropical rainforests are incredibly rich ecosystems that play a fundamental role in the basic functioning of the planet, and are home to at least 50% of the world's species, making them an extensive library of biological and genetic resources. In addition, rainforests help maintain the climate by regulating atmospheric gases and stabilizing rainfall, protect against desertification, and provide numerous other ecological functions. However, these precious systems are among the most threatened on the planet. Although the precise area is disputed, each day, at least 80,000 acres (32,300 ha) of forest disappear from earth. At least another 80,000 acres (32,300 ha) of forest are degraded. Along with them, the planet loses as many as several hundred species to extinction, the vast majority of which have never been documented by science (species loss depends on the number of species on earth. If there are 30 million species, many more will disappear daily than if there are only 5 million species). As these forests disappear, more carbon is added to the atmosphere, climatic conditions are further altered, and more topsoil is lost to erosion. Worse, is that deforestation is not slowing, but increasing at an accelerated rate. During the 1980s the deforestation rate increased by 90% and deforestation in the Brazilian Amazon reached record proportions in 1995”. According to http://www.ran.org/info_center/factsheets/04b.html, the figures are much more severe: 2.4 acres (1 hectare) destroyed each second (Equivalent to two U.S. football fields), 149 acres (60 hectares) destroyed each minute, 214,000 acres (86,000 hectares) destroyed each day (An area larger than New York City), and 78 million acres (31 million hectares) destroyed each year (An area larger than Poland). In addition, according to http://www.ran.org/info_center/factsheets/03b.html (which quotes for example from Global Biodiversity Assessment , UNEP, Cambridge University Press, 1995, and from Wilson, Edward O., The Diversity of Life , Cambridge, Mass.: Harvard University Press, 1992), “The Earth's species are dying out at an alarming rate, up to 1000 times faster than their natural rate of extinction. By carefully examining fossil records and ecosystem destruction, some scientists estimate that as many as 137 [entire] species disappear from the Earth each day, which adds up to an astounding 50,000 species disappearing every year”. According to http://www.ran.org/info_center/factsheets/04b.html, rainforests are home to some 40 to 50 percent of all life forms on our planet—perhaps as many as 30 million species of plants, animals and insects. According to http://www.sumeria.net/earth/extinct.html, “More plant and animal species will go through extinction within our generation than have been lost through natural causes over the past two hundred million years. Our single human generation, that is, all people born between 1930 and 2010 will witness the complete obliteration of one third to one half of all the Earth's life forms, each and every one of them the product of more than two billion years of evolution. This is biological meltdown, and what this really means is the end to vertebrate evolution on planet Earth. Today, the tropical rain forests are disappearing more rapidly than any other bio-region, ensuring that after the age of humans, the Earth will remain a biological, if not a literal desert for eons to come. The present course of civilization points to ecocide—the death of nature. Like a run-a-way train, civilization is speeding along tracks of our own manufacture towards the stone wall of extinction. The choice is unique to this generation. Future generations will not have the chance and those that came before us did not have the vision nor the knowledge. It is up to us.” [0005] According to http://worldforest.geo.msu.edu/rfrc/stats/wri/rank.html, the rainforests are divided among the following main countries, in descending order: Country RainForest-Hectars  1. Brazil 291,597,000  2. Indonesia 93,827,000  3. Congo 60,437,000  4. Colombia 47,455,000  5. Peru 40,358,000  6. Papua New Guinea 29,323,000  7. Venezuela 19,602,000  8. Malaysia 16,339,000  9. Myanmar 12,094,000 10. Guyana 11,671,000 11. Suriname 9,042,000 12. India 8,246,000 13. Cameroon 8,021,000 14. French Guiana 7,993,000 15. Congo, Rep 7,667,000 16. Ecuador 7,150,000 17. Madagascar 4,507,000 18. Lao Republic 3,960,000 19. Philippines 3,728,000 20. Nicaragua 3,712,000 21. Thailand 3,082,000 22. Vietnam 2,894,000 23. Guatemala 2,542,000 24. Mexico 2,441,000 25. Panama 1,802,000 26. Belize 1,741,000 27. Cambodia 1,689,000 28. Honduras 1,286,000 29. Nigeria 1,197,000 30. Gabon 1,155,000 [0006] So, clearly, most efforts should be preferably centered in the countries that lead the list, and most of all Brazil. [0007] According to http://www.wildkids.org.uk/rainforest.htm, almost 90% of West Africa's rain forest has already been destroyed. According to Leslie Taylor's book, Herbal Secrets of the rainforests (published in the USA by Prima Health in 1998), in 1950 15% of the Earth's land surface was covered by rainforests, but today they cover only 6% or less. She also quotes a report that shows that for example in 1996 statistics showed a 34% increase in deforestation since 1992, and a new report by a congressional committee that shows that the Amazon is vanishing at a rate of 20,000 square miles each year, which is more than 3 times the rate of 1994. According to statistics that she quotes, over 200,000 acres of rainforests are burned every day, which is, again, much more than the 80,000 acres per day estimate quoted above. That is more than 150 acres lost every minute, and 78 million acres lost every year! According to her data, this massive deforestation and destruction brings with it many ugly consequences, including but not limited to: Air and water pollution, soil erosion, malaria epidemics, the release of more CO2 into the atmosphere, decrease of Oxygen for us to breathe, more increase in the global warming, and of course the irrevocable loss of huge biodiversity and with them the loss of many potentially highly important plants and medicines. According to her book, “rain forest plants are complex chemical storehouses that contain many undiscovered biodynamic compounds with unrealized potential for use in modern medicine. We can gain access to these materials only it we study and conserve the species that contain them. Rainforests currently provide sources providing one-fourth of today's medicines, and 70% of the plants found to have anti-cancer properties are found only in the rainforest. The Rainforest and its immense undiscovered biodiversity holds the key to unlocking tomorrow's cures for devastating diseases. How many cures to devastating disease have we already lost? Two drugs obtained from a rainforest plant known as the Madagascar periwinkle, now extinct in the wild due to deforestation of the Madagascar rainforest, has increased the chances of survival for children with leukemia from 20 percent to 80 percent. Think about it—8 out of 10 children are now saved rather than 8 of 10 children dying from leukemia. How many children have been spared and how many more will continue to be spared because of this single rainforest plant? What if we failed to discover this one important plant among millions before it was extinct due to man's destruction? When our remaining rainforests are gone, the rare plants, animals will be lost forever and so will their possible cures to diseases like cancer.” In addition, she quotes Robert Goodland of the World Bank, who wrote that “Indigenous knowledge is essential for the use, identification and cataloguing of the [tropical] biota. As tribal groups disappear, their knowledge vanishes with them. The preservation of these groups is a significant economic opportunity for the [developing] nation, not a luxury.” She quotes statistics that in 1500 there were an estimated six to nine million Indigenous People inhabiting the rainforests in Brazil. The Western conquistadors left behind decimated cultures, and by 1900 there were only one million Indigenous People left in Brazil's Amazon, and today there are less than 250,000 Indigenous People of Brazil surviving this catastrophe, and still it continues. These surviving Indigenous People still demonstrate the remarkable diversity of the rainforest because they comprise 215 ethnic groups with 170 different languages. They live in 526 territories nationwide, which together comprise an area of 190 million acres, twice the size of California. About 188 million acres of this land is inside the Brazilian Amazon, in the states of Acre, Amapa, Amazonas, Para, Mato Grosso, Maranhao, Rondonia, Roraima, and Tocantins. Also, according to her book, it is estimated that 20% of the Earth's oxygen is produced in the Amazon rainforest. Many times whole acres are destroyed just to get to a few Teac or Mahogany trees, which are then used for example to build coffins in the USA, that are then just buried or burned. The main two causes for the destruction are wood logging and cattle ranching. [0008] Just to demonstrate the amount of Biodiversity being destroyed, she gives the following statistics. For example: [0009] One hectare (2.47 acres) of rainforest may contain over 750 types of trees and 1500 species of higher plants; [0010] A single pond in Brazil can sustain a greater variety of fish than are found in all of Europe's rivers; [0011] A twenty-five acre plot of rainforest in Borneo may contain over seven hundred species of trees—a number equal to the total tree diversity of North America; [0012] A single rainforest reserve in Peru is home to more species of birds than the entire United States; [0013] One single tree in Peru was found to harbor forty-three different species of ants—a total that approximates the entire ant species in the British Isles. [0014] It is estimated that a single Hectare of Amazon rainforest contains about 900 tons of living plants. [0015] According to http://www.ran.org/info_center/factsheets/04b.html, the current rate of destruction in the main relevant countries is ORIGI- PRESENT CURRENT NAL EXTENT AMOUNT OF EXTENT OF ANNUAL OF PRIMARY DESTRUCTION FOREST FOREST (in square km COUNTRY (in sq km) COVER COVER and in % per year) Bolivia (1,098,581) 90,000 45,000  1,500 (2.1%) Brazil (8,511,960) 2,860,000 1,800,000 50,000 (2.3%) C. America (522,915) 500,000 55,000  3,300 (3.7%) Columbia (1,138,891) 700,000 180,000  6,500 (2.3%) Congo (342,000) 100,000 80,000   700 (.8%) Ecuador (270,670) 132,000 44,000  3,000 (4.0%) Indonesia (1,919,300) 1,220,000 530,000 12,000 (1.4%) Cote D'Ivoire (322,463) 160,000 4,000  2,500 (15.6%) Laos (236,800) 110,000 25,000  1,000 (1.5%) Madagascar (590,992) 62,000 10,000  2,000 (8.3%) Mexico (1,967,180) 400,000 110,000  7,000 (4.2%) Nigeria (924,000) 72,000 10,000  4,000 (14.3%) Philippines (299,400) 250,000 8,000  2,700 (5.4%) Thailand (513,517) 435,000 22,000  6,000 (8.4%) [0016] The change must be done now, because the common wisdom so far has been that it is not urgent to take action, assuming that eventually something will be done if things get “too bad”. So unless humans realize that this wrong thinking is what has already brought us so far, the postponing of action is going to continue until the planet is irrevocably destroyed within less than one generation. Never in any time in history has any species on this planet caused so much destruction in so little time, otherwise life on this planet would have been destroyed almost completely eons ago. Various attempts have been made to motivate change, such as for example selling rainforest products that are obtained by sustainable harvesting, without destroying them, as is being done for example by Leslie Taylor, who showed that this can bring much more value per acre than destroying it, as explained below. But something was still clearly lacking, since the extent of these operations has still been very small. The main problem with this approach is that it takes time to build sufficient markets for these products and also many areas are currently inaccessible for such harvesting, so in the meantime the rest of the forest continues to be destroyed. An alternative approach has been encouraging people to donate for buying acres of the rainforests in order to save them from destruction, or even allowing people to more or less buy these acres, but many times these acres were still destroyed, because having bought it on paper still did not prevent locals from keeping destroying them. And donations clearly were not sufficient since even caring people usually only donate only relatively low amounts, whereas if a much bigger financial incentive is created, such as a real fair and lucrative investment, people will usually be ready to invest much more in it, and also much more people will want to take part in it. So clearly new approaches are needed to bring about the urgent drastic changes that are needed, by making it much more lucrative to almost anyone (for example people, and even various companies or organizations) to invest in saving the rainforests. This is clearly possible, since multinational companies that destroy the rainforests typically pay to the respective governments $2 or less for each acre that they irrevocably destroy, while taking advantage of the fact that these governments are usually suffering from heavy International debts. This is clearly ridiculous and is at the root of the folly, since clearly an indispensable natural resource of the planet is severely undersold, while its real value to the planet, in its undestroyed form, is worth many times more than that. In fact, According to an article by Peters C. M., Gentry A. H., and Mendelsohn R. O., “Valuation of an Amazonian Rainforest”, Which appeared in 1989 in Nature Magazine , Vol. 339, pp 655-656, as quoted by ran.org, the real Economic Value of One Hectare in the Peruvian Amazon is: $6,820 per year if intact forest is sustainably harvested for fruits, latex, and timber; $1,000 if clear-cut for commercial timber (not sustainably harvested), and $148 if used as cattle pasture. According to Leslie Taylor, calculations show that “if the medicinal plants, fruits, nuts, oils and other resources like rubber, chocolate and chicle (used to make chewing gums), were harvested sustainably, rainforest land has much more economic value today and more long term income and profits than if just timber were harvested or if it were burned down for cattle or farming operations. In fact, the latest statistics prove that rainforest land converted to cattle operations yields the land owner $60 per acre and if timber is harvested, the land is worth $400 per acre. However, if these renewable and sustainable resources are harvested, the land will yield the land owner $2,400 per acre. This value provides an income not only today, but year after year—for generations”. [0017] For example in 20 years from now, after all the rainforests have been destroyed, people will be willing to pay almost any price in order to be able to go back in time and get these rainforest acres back, but it will be too late. Therefore it must be possible to motivate them to do it now instead of after it becomes too late. SUMMARY OF THE INVENTION [0018] The present invention tries to solve this horrible situation by creating an organization and method for motivating as many people as possible to take immediate action. This is done preferably in at least one of the following preferable ways, but preferably a combination of most or all of them: [0019] 1. Preferably the idea of sustainable harvesting is combined with the idea of selling real acres to people. So instead of buying something only on paper, preferably an organization or multiple organizations are created, which make sure that the acres that were bought for example from the governments of the relevant countries, are indeed under supervision and protection and that preferably as many of them as possible are preferably also used for sustainable harvesting. Experience has shown that people are willing to pay even $20 or more per acre for buying land on the moon (http://moonshop.com) from a guy named Dennis Hope, whose legal rights to sell land on the moon are dubious. Yet the price that multinationals pay the governments of these countries for allowing them do destroy the rainforests is typically less than 2 dollars per acre. So it is quite possible to sell to people instead of barren acres on the moon, for a similar amount, rainforests acres that are streaming with life and are very well on the earth, together with guarding these acres and trying to make sure that these acres indeed become safe from destruction and that as many of them as possible are preferably eventually also used in a sustainable way. The acres themselves can be for example actual specific acres as defined for example by exact coordinates on a map, or for example virtual or “floating” acres, that are not bound to a single location but are more like shares in the organization that sells and takes care of these acres. Another possible variation is some combination of the above, so that for example people can choose the more general area, which can be broadly defined for example as which rainforest and/or which general part of it and/or for example some area of a few miles, and then within that area the exact acre may for example change according to various considerations or circumstances. Preferably the selling of the acres is conditional upon acceptance by the buyer of various limitations on the allowed uses of them, so that for example if the buyer himself causes destruction of the trees or animal life in the land that he bought he can for example immediately lose all rights there and/or in other rainforest acres that he bought and/or preferably have to pay a large fine. Preferably the buyers of the acres can also get for example certain royalties from the sustainable harvesting. Another possible variation is that for participating in the profits the owners have to pay for example also for additional investments needed per acre in order to run the sustainable harvesting. [0020] 2. Another possible variation is to use time limitations in the marketing scheme, both in order to motivate people to act faster and in order to emphasize and constantly remind them that the time is indeed very limited since the destruction is going on relentlessly all the time. This can be accomplished for example by setting clear rules that increase the price per acre according to the percent of rainforests remaining all the time. However, this implementation has the dangerous disadvantage that it might encourage some unscrupulous people or organization to buy up rainforest land and then continue to encourage the destruction in other parts of the rainforests on purpose in order to drive up the price of the rainforest land that they already bought. A better variation is to define a constant time scheme that is independent of the actual rate of destruction, such as for example determine that the price per acre will go up each month for example by 1% (or any other reasonable percent) or for example by a constant sum, such as for example 50 cents each month, etc., regardless of the rate of destruction. [0021] 3. Another possible variation is to give reductions in price according to quantity, so that the more acres someone buys, the less he has to pay per acre. [0022] 4. Another possible variation is to use various forms of “viral” or multilevel marketing, so that people have a direct incentive for telling more friends about this and convincing them to buy additional land, which is something missing for example from the dubious moon-acres marketing. So for example if a real rainforests acre costs for example $30 to a simple buyer, preferably he can get back for example $5 for each additional friend that he convinces to also buy an acre. Preferably this can be repeated for any amount of acres, or for example the more acres sold, the bigger the reduction to the buyer and preferably also the bigger the percent of bonus for the person who brought that buyer, so that for example if someone buys for example 100 acres, he has to pay only for example $22 per acre, and the person who brought him preferably gets a commission of for example $6 per acre sold through him. Another possible variation is to repeat this structure exponentially so that for example each person gets some commission (preferably a reduced one) also for each sale brought about by someone which he/she brought into the organization, so that for example if person A sells an acre to person B, he gets for example $5 commission for each acre sold, and if then person B sells an acre to person C, person A still gets for example a commission of $0.5 for this sale. Preferably, various limitations are added in order to limit the costs of this to the organization, so that for example this chain is limited to a certain length and/or to a certain maximum cumulative commission allowed and/or for example to a certain amount of deals and/or of acres sold. Another possible variation for adding even more to the safety of the people getting involved is adding the improvement that users can for example preferably have an option of delayed payment, so that they can for example buy the acres temporarily without paying for them and then have a grace period of for example 1-3 months for actually paying and keeping the acres, so that in the meantime they can see if they can sufficiently continue selling acres to others and getting those others to preferably sell to additional others, so that before the end of the grace period they can already have a good estimate if it was worth it, even before they have to spend a single real dollar. Another possible variation is that this does not have to be an all-or-nothing decision, so that the buyer can for example decide to keep only some of the acres by paying for them, and then the others in which he didn't finalize the sale go back to the available pool. Also, preferably the participants don't have to buy acres in order to sell these acres or other acres to others, but can act as agents even without buying any acres themselves at all, thus still getting commissions for each sale. This way for example users can buy many more acres than they could normally afford, by simply selling more acres to others and encouraging them to help sell acres too, so that they can finance their buying by their commissions, and in addition, preferably through trial the period, they can know in advance more or less how their balance is going to look like before even having to spend any real money for finalizing their buying of acres. To the best of my knowledge this type of “safe testing period” has never been used in any multilevel marketing scheme in any area in the current state of the art. Of course, in this variation, preferably all commissions are also contingent, depending on the further buyer to actually make the deal real. In addition to this, preferably this structure can be traced for example on the Internet so that each user can know at all times how many “agents” are working in the logical tree below him at any time and/or preferably how many acres each of them sold and preferably what his credit status is at any time, etc. [0023] 5. Another possible variation is to issue for example, preferably in addition, at least once in a while also public stocks of the organization itself, so that more funds can be gained for supporting its causes and especially for buying as many acres as possible in advance. [0024] Of course, various combinations of the above and other variations can also be used, both within the solutions and across them. [0025] Another problem is how to make sure that the rainforest lands bought indeed become protected, preferably in an efficient and cost-effective way, and how to start indeed sustainable harvesting in these lands. Of course, sustainable harvesting cannot be done at once in all the areas, and is also limited for example by market forces, such as for example the current world demand for a certain product, and the lack of accessibility to many areas. Therefore, preferably the organization does not guarantee that each acre will be used for producing anything but only for example that it will do its best to implement it in as many acres as possible. Therefore, when it comes to the sustainable harvesting, preferably each buyer becomes a partner in the total income of the organization from the sustainable harvesting, preferably proportionally to the number of acres that he owns. Various preferable solutions are possible for guarding the bought acres against destruction: [0026] 1. Making deals with the respective governments so that by getting the much higher prices per acre than the $2 or less that they get for allowing to destroy each acre, they will also be obliged to guard at least the bought areas for example by Extended police forces and/or by parts of the army, and/or for example by other special forces designated for this. Another possible variation is that preferably the governments have to agree in return to change the laws if needed so that destroying rainforest lands and/or especially any of the lands that were already paid for, becomes punishable by preferably huge fines and preferably also imprisonments, so that even without intensive guard all the time, the motivation for destroying rainforests becomes much lower. [0027] 2. Making deals with the local populations and/or with indigenous natives, wherein they are paid for example a certain amount per month to guard large areas or at least to issue a warning immediately as soon as they spot dangerous or suspect activities, etc. However, this creates additional monthly expenses, so if used, it is preferably combined with at least some sustainable harvesting which can thus help cover these monthly expenses. In this case, preferably the same locals used for guarding the areas are preferably also employed for the sustainable harvesting. In fact, letting local people work for the sustainable harvesting and preferably also get additional revenues from the profits from the sustainable harvesting is very preferable, since otherwise they themselves take part in the destruction. Another possible variation is to use, in addition or instead, hi-tech surveillance, such as for example through preferably low orbiting satellites, and/or for example zeppelins and/or balloons, that preferably report, preferably in real time, the conditions of the entire rainforests or at least large parts of them, so that any suspect or dangerous events can preferably be instantly spotted and appropriate action can be taken. [0028] 3. Creating different sources for fuel and for wood than rainforests, thus supplying the demand and removing much of the incentives that currently exist for continuing to destroy the rainforests. This can be done for example by encouraging and promoting the use of fast-growing plants that can easily replace wood, such as for example Kanef and/or industrial Hemp, which make in fact better wood fibers than ordinary trees and grow much faster. Hemp can grow for example to the size of a full tree within a few months, and has longer and better fibers than normal wood, so it can be used for example for creating better logs and/or fiber-boards, and can be also used for example for extracting Biomass fuel, for example in the form of Methylic Alcohol, which is much less polluting than current Gasoline, and is of course much more sustainable. Some of these plants can even be planted in rainforests lands that were already destroyed and deserted, since these are very resilient plants that can grow even is such destroyed places. [0029] 4. Preferably, in addition to the above, Class Action suits are filed, preferably against the multi-national organizations who destroy rainforests and/or against governments that allow it, on account of crimes against humanity, which are therefore relevant to the entire 6 billion humans that inhabit this planet and also to their progeny, who will all suffer the consequences of these acts. [0030] Of course, various combinations of the above and other variations can also be used, both within the solutions and across them. [0031] Important Clarification and Glossary: [0032] Throughout the patent when variations or various solutions are mentioned, it is also possible to use various combinations of these variations or of elements in them, and when combinations are used, it is also possible to use at least some elements in them separately or in other combinations. These variations are preferably in different embodiments. In other words: certain features of the invention, which are described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. “User” or “users” or “buyer” or buyers” as used throughout the patent, including the claims, can interchangeably be either single or plural, and can refer to both sexes even when words such as for example “he” or “she” or “his” or “her” are used. Although the land units have been described for convenience mainly in acres, this is just an example, so thought the patent, including the claims, “acre” can mean an actual acre, or any other convenient units or sub-units of area. Throughout the patent, including the claims, the words “organization” or “organizations” can interchangeably mean either single or plural organizations. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0033] All of the descriptions in this and other sections are intended to be illustrative examples and not limiting. [0034] The above preferable solutions are hereby described in more detail: [0035] 1. Preferably the idea of sustainable harvesting is combined with the idea of selling real acres to people. So instead of buying something only on paper, preferably an organization or multiple organizations are created, which make sure that the acres that were bought for example from the governments of the relevant countries, are indeed under supervision and protection and that preferably as many of them as possible are preferably also used for sustainable harvesting. Experience has shown that people are willing to pay even $20 or more per acre for buying land on the moon (http://moonshop.com) from a guy named Dennis Hope, whose legal rights to sell land on the moon are dubious. Yet the price that multinationals pay the governments of these countries for allowing them do destroy the rainforests is typically less than 2 dollars per acre. So it is quite possible to sell to people instead of barren acres on the moon, for a similar amount, rainforests acres that are streaming with life and are very well on the earth, together with guarding these areas and trying to make sure that these acres (and preferably also as many other unsold acres as possible) indeed become safe from destruction and that as many of them as possible are preferably eventually also used in a sustainable way. The acres themselves can be for example actual specific acres as defined for example by exact coordinates on a map, or for example virtual or “floating” acres, that are not bound to a single location but are more like shares in the organization that sells and takes care of these acres. Another possible variation is some combination of the above, so that for example people can choose the more general area, which can be broadly defined for example as which rainforest and/or which general part of it and/or for example some area of a few miles, and then within that area the exact acre may for example change according to various considerations or circumstances. Preferably users can also name acres after their name or after names of others and are preferably encouraged also for example to buy them as gifts to friends and relatives. Preferably users can also see their bought acres or at least their general area or areas, for example by live feed on the Internet, for example through satellites and/or balloons and/or zeppelins. Preferably there are various zoom functions available and the users can focus on various areas, and preferably interactive maps are available that show in real time for example areas already bought, areas not bought yet, areas that are already destroyed, areas that are currently being destroyed, etc. This is preferably done by using multiple, preferably wide angle, cameras on preferably multiple zeppelins and/or balloons and/or satellites, and/or allowing the users also to give remotely various commands to at least some of said cameras, such as for example changing angle and/or focus. Another possible variation is that various cameras for example constantly rotate and/or change focus and the users can view various areas based on the recently acquired relevant images. Preferably people can see on the Internet all the time the current status of the amount of acres bought and sold by the organization and also preferably a constant update on the rates and areas of continuing destruction. Another possible variation is that people can also see for example the lists of all those who already bought acres and/or the amounts they bought, except for example in case certain buyers explicitly request to remain anonymous. In case that any of relevant governments do not agree for example to the acres becoming fully owned by foreign citizens, preferably the selling is done so that at least some ownership rights remain also in local hands or in the hands of these governments. For example in Brazil and in Peru foreign citizens are not allowed by law to buy land, so at least for the countries that have these limitations, preferably instead of the acres themselves, for example what is sold is only the sustainable harvesting rights for example for the next 10 years or next 100 years, etc. Another possible variation is that what is sold is for example preferably a lease—for example for the next 100 years, while officially the land still remains for example under the ownership of the government or for example under the ownership of a branch of the organization that is locally incorporated, so that for example the organization really buys the acres but the clients only lease them for a time that to a human seems like forever but for Nature is nothing. Another possible variation is that the buyers just buy shares in the organization, except that the organization is preferably compelled to buy for each acre paid for at least one real acre of rainforests, so that the buyers know that they paid for a real acre, thus both saving the rainforests, and getting the right to really own such an acre (except of course for the limitation that they may use it only according to the limitations set by the organization). Therefore, preferably the selling of the acres is conditional upon acceptance by the buyer of various limitations on the allowed uses of them, so that for example if the buyer himself causes destruction of the trees or animal life in the land that he bought he can for example immediately lose all right there and/or in other acres that he bought and/or preferably have to pay a large fine. Preferably the buyers of the acres can also get for example certain royalties from the sustainable harvesting. Another possible variation is that for participating in the profits of the sustainable harvesting the owners have to pay for example also for additional investments needed per acre in order to run the sustainable harvesting. The entire scheme is based on the assumption that if the governments of the rainforest areas are paid considerably more per acre by the organization than what they get for example from multinational organizations that pay for example $2 for each acre that they irrevocably destroy, then they will prefer to sell to the organization. Preferably they will even more prefer to sell to the organization, when they take into consideration that this way in fact they are saving the rainforests instead of destroying them, and during the process get much more compensation for them. Preferably the governments get also, in addition, for example some percent of the revenues from the sustainable harvesting, for example in the form of taxes and/or additional commission. Preferably the organization itself is a non-profit organization, so that most or all of the profits go back to further helping to save the rainforests (except for example money needed for advertising, Public Relations, etc.), and thus also people will have more sympathy and trust towards it. Preferably the contract that the buyers have to agree to includes also acknowledging also the rights of the indigenous natives who populate these areas, such as for example the Amazonian Indian, so that they also become part of the process to the extent possible. Of course the acres are preferably not purchased one by one but in preferably large bunches, which makes overhead and paperwork costs much cheaper. This can be done by either the organization buying each time a sufficiently large bunch in advance, and/or for example accumulating orders together for example each month or more (or any other convenient time period) and only then doing the actual purchase as one transaction. This way all the licensing fees and other related expenses are also done preferably in large bunches, preferably in advance, even for example for acres not bought yet, which means that the overhead cost per single acre should become negligible. Similarly, for example harvesting experts are used preferably for determining the harvesting recommendation for large areas each time and not on an individual acre basis. Preferably, the best and largest rainforest lands owned by the government are located and bought from the government at a fixed price and fixed procedure for example after reaching an agreement that will be used also for all later purchases. Of course, preferably the buyers can share also other potential revenues from the sold and/or leased areas, such as for example tourism, revenues from displaying live feeds, etc. Another possible variation is preferably planting and growing at least in some areas various additional appropriate plants and/or trees that can preferably be used for food in these areas in a way that doesn't damage the existing trees, plants, animals, and/or soil (These are preferably indigenous plants that already exist in the area. However, if this is done, it must be done carefully so as not to disrupt ecological balances). [0036] 2. Another possible variation is to use time limitations in the marketing scheme, both in order to motivate people to act faster and in order to emphasize and constantly remind them that the time is indeed very limited since the destruction is going on relentlessly all the time. This can be accomplished for example by setting clear rules that increase the price per acre according to the percent of rainforests remaining all the time. However, this implementation has the dangerous disadvantage that it might encourage some unscrupulous people or organization to buy up rainforest land and then continue to encourage the destruction in other parts of the rainforests on purpose in order to drive up the price of the rainforest land that they already bought. A better variation is to define a constant time scheme that is independent of the actual rate of destruction, such as for example determine that the price per acre will go up each month for example by 1% (or any other reasonable percent) or for example by a constant sum, such as for example 50 cents each month, etc., regardless of the rate of destruction. [0037] 3. Another possible variation is to give reductions in price according to quantity, so that the more acres someone buys, the less he has to pay per acre. [0038] 4. Another possible variation is to use various forms of “viral” or multilevel marketing, so that people have a direct incentive for telling more friends about this and convincing them to buy additional land, which is something missing for example from the dubious moon-acres marketing. So for example if a real rainforests acre costs for example $30 to a simple buyer, preferably he can get back for example $5 for each additional friend that he convinces to also buy an acre. Preferably this can be repeated for any amount of acres, or for example the more acres sold, the bigger the reduction to the buyer and preferably also the bigger the percent of bonus for the person who brought that buyer, so that for example if someone buys for example 100 acres, he has to pay only for example $22 per acre, and the person who brought him preferably gets a commission of for example $6 per acre sold through him. Another possible variation is to repeat this structure exponentially so that for example each person gets some commission (preferably a reduced one) also for each sale brought about by someone which he/she brought into the organization, so that for example if person A sells an acre to person B, he gets for example $5 commission for each acre sold, and if then person B sells an acre to person C, person A still gets for example a commission of $0.5 for this sale. Preferably, various limitations are added in order to limit the costs of this to the organization, so that for example this chain is limited to a certain length (for example up to N levels in the tree) and/or to a certain maximum cumulative commission allowed and/or for example to a certain amount of deals and/or of acres sold. This multilevel marketing is of course similar to various Pyramid schemes, except that in this case there is a very real product, and also it is for a very good cause. However, there are also additional Improvements, as explained below: Another problem with normal “Pyramid Schemes” is that many times people are afraid to lose money if they are not successful in selling the product forward, such as for example in the case of products like “Lifestiles”, in which each participant is required to spend an expensive sum just to “get into the game”. However, the real danger and the real test for the legitimacy of any Pyramid scheme depends clearly on the nature of the “product” sold, since if the product is not worth the money paid for it, than obviously the only profit can come from selling it in time to a greater “sucker” who is willing to pay more for it, until certainly there will come a time where the buyers are no longer able to sell it to other buyers, and then the entire “Pyramid” crushes. An example of this is for example during a stock market bubble, such as happened for example with the NASDAQ before the crash that began at the end of March 2000, when people bought stocks clearly many times above their real value, but still thought they will be able to get out in time by selling it to someone else who will still be willing to pay more in the hope of also making some “quick buck” and exiting. On the other hand, when the value of the product is real, and preferably no unregulated speculation is allowed, then clearly no crash at the end is expected, since even the last buyers should have no problem. Therefore, in order to prevent later speculation and/or to prevent circumventing the purposes of the organization, preferably when anyone buys one or more acres the selling contract itself is conditional so that he may not resell his rainforest acres or other rainforest acres except to persons who also agree to the same terms, and may sell it only according to the prices allowed by the organization at that time. Another possible variation for adding even more to the safety of the people getting involved is adding the improvement that users can for example preferably have an option of delayed payment, so that they can for example buy the acres temporarily without paying for them and then have a grace period of for example 1-3 months (or any other convenient or reasonable period) for actually paying and keeping the acres, so that in the meantime they can see if they can sufficiently continue selling acres to others and getting those others to preferably sell to additional others, so that before the end of the grace period they can already have a good estimate of how many acres they can afford or if it was worth it, even before they have to spend a single real dollar. (The same grace period is preferably automatically applicable at all levels of the tree, so that the moment someone agrees to buy he/she preferably has automatically the same standard grace period to decide. Another possible variation is that the buyer is limited to the same grace period of the person that sells to him/her, so that for example if the seller has only part of his grace period left for given acres, the people that buy through him are preferably limited in those acres to the same remaining part of the grace period that the seller has). Another possible variation is that the grace period is for example dependent on the amount of acres involved in each deal. Another possible variation is that preferably users can buy acres from the organization at cheaper rates depending on the amount of acres that they have already bought and/or sold so far. Another possible variation is that this does not have to be an all-or-nothing decision, so that the buyer can for example decide to keep only some of the acres by paying for them, and then the others in which he didn't finalize the sale preferably go back to the available pool. Another possible variation is that at least some small deposit needs to be made in advance on account for each acre bought, which is nonrefundable if the buyer cancels. Also, unlike Lifestiles for example, preferably the participants don't have to buy acres in order to sell these acres or other acres to others, but can act as agents even without buying any acres themselves at all, thus still getting preferably the same or different commissions for each sale. This way for example users can buy many more acres than they could normally afford, by simply selling more acres to others and encouraging them to help sell acres too, so that they can finance their buying by their commissions, and in addition, preferably through the trial period, they can know in advance more or less how their balance is going to look like before even having to spend real money for finalizing their buying of acres. To the best of my knowledge this type of “safe testing period” has never been used in any multilevel marketing scheme in any area in the current state of the art. Of course, in this variation, preferably all commissions are also contingent, depending on the further buyer to actually make the deal real. Another possible variation is that the more acres each person owns, the higher commission he can get for direct and/or indirect sales. In addition to this, preferably this structure can be traced by the users for example on the Internet so that each user can know at all times how many “agents” are working in the logical tree below him/her at any time and/or preferably how many acres each of them sold and preferably what his credit status is at any time, etc. A similar scheme to this (with any one or more of the above variations) can be used for example also for marketing any other real product for example on the Internet, and also for example for marketing stocks or shares for example in any Internet company, even without payment in advance, so that for example the users “play” with accumulating credit points, which can later become for example options that can be converted into real property when the company becomes of real value and thus the user can then have the choice of for example paying some real money and converting his options into real shares. [0039] 5. Another possible variation is to issue for example, preferably in addition, at least once in a while also public stocks of the organization itself, so that more funds can be gained for supporting its causes. [0040] Of course, various combinations of the above and other variations can also be used, both within the solutions and across them. Altogether, since there are about 2 billion acres and about 6 billion humans on this planet, it means that theoretically on average it is sufficient that for example 1 in every 3 persons in the world will buy on average just 1 acre in order to save the entire remaining rainforest acres. Of course many people on the third world cannot afford even that, but on the other hand many people in the developed countries who understand the real value of this can buy much more than 1 acre, once they realize that on the long run this is one of the best investments they can ever make. Of course, someone like Bill Gates for example could buy the whole two billion acres alone. Of course the organization or organizations described here can also become an integral part of various governments, such as for example the government of Brazil itself. [0041] Another problem is how to make sure that the rainforest lands bought indeed become protected, preferably in an efficient and cost-effective way, and how to start indeed sustainable harvesting in these lands. Of course, sustainable harvesting cannot be done at once necessarily in all the areas, and is also limited for example by market forces, such as for example the current world demand for a certain product. Therefore, preferably the organization does not guarantee that each acre will be used for producing anything but only for example that it will do its best to implement it in as many acres as possible. Therefore, when it comes to the sustainable harvesting, preferably each buyer becomes a partner in the total income of the organization from the sustainable harvesting, preferably proportionally to the number acres that he owns, and preferably additional investment is needed in order to participate in this, unless for example the buyer wants to go there and run the sustainable harvesting of his acres by himself. Various preferable solutions are possible for guarding the bought acres against destruction: [0042] 1. Making deals with the respective governments so that by getting the much higher prices per acre than the $2 or less that they get for allowing to destroy each acre, they will also be obliged to guard at least the bought areas for example by Extended police forces and/or by parts of the army, and/or for example by other special forces designated for this. Another possible variation is that the preferably governments have to agree in return to change the laws if needed so that destroying rainforest lands and/or especially any of the lands that were already paid for, becomes punishable by preferably huge fines and preferably also imprisonments and actually enforce these rules, so that even without intensive guard all the time, the motivation for destroying rainforests becomes much lower. [0043] 2. Making deals with the local populations and/or with indigenous natives, wherein they are paid for example a certain amount per month to guard large areas or at least to issue a warning immediately as soon as they spot dangerous or suspect activities, etc. However, this creates additional monthly expenses, so if used, it is preferably combined with at least some sustainable harvesting which can thus help cover these monthly expenses. In this case, preferably the same locals used for guarding the areas are preferably also employed for the sustainable harvesting. In fact, letting local people work for the sustainable harvesting and preferably also get additional revenues from the profits from the sustainable harvesting is very preferable, since otherwise they themselves take part in the destruction. According to Leslie Taylor, in Brazil for example the government encourages poor people to grab possession of forest lands and destroy them, with the motto of “land without men for men without land”, so that poor people squatter and destroy rainforest acres and create farms, but a short time afterwards the depleted land becomes useless and they have to move on to destroy more rainforest acres. Of course this motto also ignores the fact these the land are not really “without men” but are already populated by native Indians. She also quotes one Brazilian Official's public statement that “not until Amazonas is colonized by real Brazilians, not Indians, can we truly say we own it”. This attitude can lead to the sad realization that descendents of those same conquistadors who were directly or indirectly responsible for the depletion of these Indian populations during the last 500 years are also the ones who are now finishing the “job” of their ancestors by also destroying or allowing to destroy those rainforest lands for which they apparently don't have sufficient regard or appreciation of their true value. In order to stop this Locust-like behavior, clearly these masses of people have to be taken into account and become part of the solution. Another possible variation is to use, in addition or instead, hi-tech surveillance, such as for example through preferably low orbiting satellites, and/or for example zeppelins and/or balloons, which are much cheaper, that preferably report, preferably in real time, the conditions of the entire rainforests or at least large parts of them, so that any suspect or dangerous events can preferably be instantly spotted and appropriate action can be taken. Of course, since satellites are very expensive, preferably the organization uses services from existing surveillance satellites, such as for example NASA'a Terra MODIS Earth Observing Satellites. However another problem with satellites is that the stationary satellites that constantly cover the same area are at much higher orbit and thus have less resolution, whereas low orbiting satellites typically reach the same area only once every few hours or for example once a day or more, which might not be sufficient for real-time alerts. Preferably more Real-time alerts and more detailed data are used, because for example according to http://newsroom.msu.edu/news/archives/2003/02/rainforests.html, which quotes a recent report in Nature Magazine of Feb. 27, 2003, there are many small rainforests fires which can be easily stopped, but if neglected they can lead to subsequent huge intensity fires that are extremely difficult to put out. Zeppelins or balloons can be much cheaper and can remain constantly over the same areas and can still be also much lower than satellites. (The Zeppelins and/or balloons can be for example manned and/or for example small and preferably automatic or remote controlled. Preferably both types are used, for various purposes). Preferably these or other balloons or zeppelins are used also as one of the methods of carrying harvests from various areas, so that at least some of the problems of accessibility are solved this way. Preferably zeppelins and/or balloons can land for example in a few cleared areas that are preferably dispersed as needed or for example they stay above the canopy and the cargo is pulled up to them with ropes, which can for example be lowered from the zeppelin or balloon, or for example the rope is sent up with a smaller balloon and then the zeppelin pulls up the cargo that is attached to the rope on the ground. Preferably the zeppelins and/or balloons are powered by solar energy. Another possible variation is to use for example special vehicles that can move on any terrain without roads, for example vehicles that simulate animal legs, and/or for example use various animals that can carry cargo without roads. Another possible variation is to increase the price of the acres in order to finance also the guarding fee, so that for example as more acres are sold each month, they also help pay for the guarding of themselves and of the already sold acres. Theoretically of course guarding each acre separately would make it far too expensive, however since the acres are preferably parts of much larger clusters, the guarding is preferably more at the borders of these larger areas, so it is much cheaper when calculated as cost per acre, and it should become even cheaper per acre as more acres are sold. Anyway, if the organization can sustainably harvest for example even just 10% of the purchased acres and make for example just $1000 per acre per year by this, the average income per acre becomes $100 per year, which is quite enough for paying both for the guarding expenses and for the part of the profit that the client is entitled to, so that the organization can easily sustain itself. If for example the profit is $2400 per acre like Leslie Taylor's estimate or higher like for example the above higher estimate, and/or if a larger percent of the purchased acres can be sustainable harvested like this, then the figures are even much better. [0044] 3. Creating different sources for fuel and for wood than rainforests, thus supplying the demand and removing much of the incentives that currently exist for continuing to destroy the rainforests. This can be done for example by encouraging and promoting the use of fast-growing plants that can easily replace wood, such as for example Kanef and/or industrial Hemp, which make in fact better wood fibers than ordinary trees and grow much faster. Hemp can grow for example to the size of a full tree within a few months, and has longer and better fibers than normal wood, so it can be used for example for creating better logs and/or fiber-boards, and can be also used for example for extracting Biomass fuel, for example in the form of Methylic Alcohol, which is much less polluting than current Gasoline, and is of course much more sustainable. Some of these plants can even be planted in rainforest lands that were already destroyed and deserted, since these are very resilient plants that can grow even is such destroyed places. It should be kept in mind that in recent years, except for the USA and a few other countries, in much of the world growing industrial hemp is legal now, including for example In North America: Canada; in Western Europe at least: England, Germany, France, Spain, Portugal, Austria, Denmark, Holland, Ireland, Italy and Switzerland; In Eastern Europe at least: Russia, Hungary, Romania, Poland, Slovenia, Croatia, Czech Republic and Ukraine; In East Asia at least: China, India, Korea and Thailand; In south America: At least Chile and Nicaragua; and it is also legal for example in South Africa, in Egypt, and in New Zealand. [0045] 4. Preferably, in addition to the above, Class Action suits are filed, preferably against the multi-national organizations who destroy the rainforests and/or personally members of their managements that are involved in making these decisions and/or against governments and/or specific politicians that allow it, preferably on account of crimes against humanity, which are therefore relevant to the entire 6 billion humans that inhabit this planet and to their progeny who will all suffer the consequences of these acts. It is clear to see from the above descriptions of the consequences of destroying the rainforests that at least some of these consequences have an affect on every living creature on this planet, including the humans. Preferably these class suits are filed, to the extent possible, both in the countries where the destruction takes place, and in the countries where the centers of these multinational corporations are located, such as for example in the USA. Another possible variation is to try to file them also in any other country where the class suit system is sufficiently developed to allow this, since the victims are in every country on this planet. This is important both for bringing these issues more to the consciousness of everyone (since each such class action can get large media coverage), and for halting these organizations, since otherwise organizations that buy acres for $2 and make instantly $400 per acre have more buying power than an organization as described in this invention, who's income is based more on the long run. This is also important for showing those multinationals and governments that they ARE indeed accountable for what they are doing and will have to account for their actions now or in the future, in a way that preferably will also hurt them deeply in their pockets, and cannot escape or hide behind the claim that they are not the only ones responsible. However, since most of these governments are very poor, preferably those rich multinationals are sued also for paying back damages for the destruction already caused by them, whereas these governments are preferably sued only for future damages unless they immediately change their policies that allow the destruction to go on. Another possible variation is to also try to put on trial some of the above parties in the International tribunal in Hague for crimes against humanity. There is no problem of financing this, since class suits are almost invariably done by contingency lawyers, so there are practically no costs to the organization. These huge class action suits will probably eventually occur anyway, if not now, then after much more additional destruction has occurred or after the rainforests are completely gone, so it is much more preferable to do it now, while it can still lead to preventing a lot of the damage that is about to occur during the next few years. Another possible variation is, preferably in combination with these class action suits, to encourage consumer groups to boycott various products and/or companies that are responsible for large scale destruction of rainforests, such as for example Cow products from cows that are raised in these areas, etc. In addition, preferably the organization uses profits from the marketing of the acres and/or from the sustainable harvesting to invest in ecological education, preferably both in the countries where the main rainforests exists and also in other countries. [0046] Of course, various combinations of the above and other variations can also be used, both within the solutions and across them. [0047] While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications, expansions and other applications of the invention may be made which are included within the scope of the present invention, as would be obvious to those skilled in the art.

The destruction of the rainforests in the last decades has become the biggest crime against humanity, animals and Nature. Various statistics show that at the current rate of destruction, unless drastic changes are made right now, by the year 2020 or even considerably earlier, 90-100% of all the rainforests will be irrevocably destroyed, causing damages that will take MILLIONS OF YEARS to repair, if at all. The present invention tries to solve this by creating a strong financial incentive that makes preserving the rain forests much more profitable than destroying them. Preferably sustainable harvesting is combined with selling real acres to people and making sure that these acres are indeed under supervision and protection and that preferably as many of them as possible are also used for sustainable harvesting. This is preferably combined with a recursive multi-level marketing plan with various sophisticated improvements over the prior art.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to magnetic separation generally and, more particularly, but not by way of limitation, to a novel apparatus that permits the automatic separation of magnetic components in a laboratory microplate. [0003] 2. Background Art [0004] In the field of biology, there are requirements for the separation of one constituent from another. Some of the more commonly used methods are centrifugation, filtration, and magnetic separation. Centrifugation uses centrifugal force to provide separation by elements of mass. Filtration provides separation by size. Magnetic separation uses a magnetic field to attract and hold magnetic particles, or magnetic beads, so that the supernate in which the suspended are disposed can be removed. [0005] Magnetic beads are particularly useful in immunoassays. Constituents of interest may be coated on the surface of paramagnetic particles. Using an applied magnetic field, the beads may be congregated and retained from the surrounding liquid reagents of reactants. U.S. Pat. No. 5,779,907, issued Jul. 14, 1998, to Yu, and titled MAGENTIC MICROPLATE SEPARATOR, describes a means and method of providing magnetic separation. As described in the patent, a laboratory tray, or microplate, containing a number of vertical wells is placed on a fixture having a number of upstanding cylindrical magnets. The arrangement of wells and magnets is such that each magnet is disposed adjacent four of the wells. Thus, a 96-well plate requires a fixture that has 24 magnets. The magnetic components in the wells are attracted to the sides of the wells adjacent the magnets. The supernate in the wells can then be removed. The apparatus described by Yu is entirely satisfactory for manual use; however, it does not meet the need of processing the large numbers of samples that are required in the fields of genomic and drug discovery research. Automation is required for processing large numbers of samples. [0006] Conventionally, in automated magnetic separation systems, a robotic arm moves the laboratory trays over a fixed plate of magnets. While this provides an improvement over the manual method, it requires an additional positioning of the laboratory tray. [0007] Accordingly, it is a principal object of the present invention to provide an apparatus for magnetic separation that does not require a separate step of positioning of the laboratory plate. [0008] It is a further object of the invention to provide such an apparatus that can be remotely and automatically controlled. [0009] It is an additional object of the invention to provide such an apparatus that can be economically constructed using conventional techniques. [0010] It is another object of the invention to provide such an apparatus that can be part of a robotic liquid handling system. [0011] Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures. SUMMARY OF THE INVENTION [0012] The present invention achieves the above objects, among others, by providing, in a preferred embodiment, an apparatus for automated magnetic separation of materials in laboratory trays, comprising: a frame upon an upper surface of which a multiwell laboratory tray may be placed, a base plate on which is mounted a plurality of upstanding magnets disposed below said upper surface; and means to raise said base plate such as to insert said upstanding magnets into interwell spaces in said laboratory tray. BRIEF DESCRIPTION OF THE DRAWING [0013] Understanding of the present invention and the various aspects thereof will be facilitated by reference to the accompanying drawing figures, provided for purposes of illustration only and not intended to define the scope of the invention, on which: [0014] [0014]FIG. 1 is an isometric view of a microplate positioned over a plate of magnets. [0015] [0015]FIG. 2 is a side elevational view of the invention, partially in cross-section, with a plate of magnets in lowered position. [0016] [0016]FIG. 3 is a side elevational view of the invention, partially in cross-section, with a plate of magnets in raised position, such that the magnets are disposed between the wells of the microplate. [0017] [0017]FIG. 4 is a block/schematic view of a control system for the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0018] Reference should now be made to the drawing figures on which similar or identical elements are given consistent identifying numerals throughout the various figures thereof, and on which parenthetical references to figure numbers direct the reader to the view(s) on which the element(s) being described is (are) best seen, although the element(s) may be seen on other figures also. [0019] [0019]FIG. 1 illustrates a microplate 10 having a plurality of vertical wells, as at 12 , positioned over a plate of magnets 14 having a plurality of upstanding cylindrical magnets, as at 16 Wells 12 and magnets 16 are arranged such that, when microplate 10 and plate of magnets 14 are brought together, each magnet 16 will be moved into one of a plurality of positions, as at 20 , in the microplate and, so disposed, each magnet will be adjacent four of the wells. Microplate 10 is shown as having 96 wells arranged in a 8×12 matrix and plate of magnets 14 consequently has 24 magnets. It will be understood, however, that the invention may be applied as well to other numbers of microplate wells. In this position, the magnetic flux surrounding each magnet 16 encompasses four adjacent wells 12 . Paramagnetic particles in wells 12 will be attracted by this field and will be drawn to the sidewalls of the wells, adjacent to each magnet 16 . The supernate can then be withdrawn from the wells by, for example, aspiration. [0020] [0020]FIG. 2 illustrates an apparatus, constructed according to the present invention, and generally indicated by the reference numeral 50 . Apparatus 50 includes a frame 60 having a horizontal bottom plate 62 and a horizontal top plate 64 , the latter having a plurality of vertical holes defined therethrough, as at 66 . A plurality of upstanding vertical magnets, as at 70 , is fixedly attached to a horizontal, non-magnetic base plate 72 that includes four bearings 74 (only two shown) journaled on four vertical guide pins 76 (only two shown) extending between and fixedly attached to bottom plate 62 and top plate 64 . Thus arranged, base plate 72 may move vertically upwardly and downwardly in frame 60 . Base plate 72 is held in its down position against four stops 80 (only two shown) fixedly attached to bottom plate 62 by the action of four compression springs 82 (only two shown) disposed around guide pins 76 and compressed between the lower surface of top plate 64 and the upper surface of the base plate. [0021] A flexible bladder 90 disposed between the upper surface of bottom plate 62 and the lower surface of base plate 72 provides the motive force to raise the base plate. Bladder 90 may be simply constructed from a bicycle inner tube that is clamped between two clamps 100 fixedly attached to bottom plate 62 . One of clamps 100 is fitted with an air line connection (not shown) to permit flow of pressurized air to the closed interior of bladder 90 . [0022] As shown on FIG. 2, a microplate 110 having a plurality of vertical wells 1 12 has been placed on the upper surface of top plate 64 . Since base plate 72 is shown in its lowered position, magnets 70 are spaced below wells 112 . [0023] [0023]FIG. 3 illustrates the elements of apparatus 50 described above (FIG. 2), with pressurized air having been introduced into bladder 90 . The inflation of bladder 90 causes base plate 72 to rise, that motion causing magnets 70 to extend through openings 66 and between wells 112 . As will be understood from inspection of FIG. 1 and the accompanying text, each of magnets 70 will be inserted adjacent four of wells 112 in microplate 110 . Supernate can now be removed from wells 112 by any suitable means such as by aspiration of the supernate.. Expansion of bladder 90 is limited by the confines of frame 60 . The upward force provided by the inflation of bladder 90 exceeds the downward forces being applied by compression springs 82 , permitted the elevation of base plate 72 . Venting of compressed air from bladder 90 will cause the bladder to collapse and base plate 72 to return to its lowered position (FIG. 2) by means of the downward force provided by compression springs 82 . [0024] [0024]FIG. 4 illustrates a control system that may be used with apparatus 50 , the control system being generally indicated by the reference numeral 200 . Control system 200 includes a system controller 210 that may be a section of a controller used to control other features of a complete analysis system. Controller 210 is operatively connected to control a three-way solenoid valve 220 that permits compressed air from a compressed air source 222 to inflate bladder 90 to raise base plate 72 to its elevated position (FIG. 3) or to vent air from the bladder to cause the base plate to move to its lowered position (FIG. 2). [0025] The present invention provides a simple and effective means of moving magnets into the interwell spacing of a microplate by remote means. In the case described, low air pressure applied to a bladder, lifts the magnets. [0026] Using a remotely controlled method of actuating the magnets into the interwell spacing permits the inclusion of the device into a liquid handling robot. This permits completed automation of the entire liquid handling function. The first step in bioassays, using magnetic beads or particles, is to react the coated elements on the beads with other liquid reagents. This requires the beads to be in suspension to provide full exposure of the reacting elements. Normally, some means of agitation is incorporated, such as shaking or multiple aspirations dispensings. [0027] Following the reaction step is the separation step. A magnetic field is applied, drawing the magnetic beads to the sidewalls of the containing well. This separates the beads from the liquid in the well, permitting the liquid to be withdrawn by an automated pipettor. This process may be repeated multiple times, depending on the assay protocol and how many different reagent reactions are required. [0028] By the use of a remote means of controlling the insertion of the magnets, the action may by easily accommodated in liquid handling robotics control systems, such as supplied by Tomtec, Inc., of Hamden, Conn. An actuating signal is generated in the control system software This signal controls an electrically operated solenoid valve that applies controlled air pressure to the device operating the magnets. By being small and compact, the magnetic device can be located directly on the robot's operating deck. In other words, frame 60 (FIGS. 2 and 3) simply replaces what would have been a fixed nest, to hold the microplate being used for the test. [0029] This simplicity eliminates the necessity of physically moving the microplate from the station where it receives the reagent, without magnetization, to a station with magnetization. The invention permits the system control to apply magnetization on demand where and when it is required. [0030] In the embodiments of the present invention described above, it will be recognized that individual elements and/or features thereof are not necessarily limited to a particular embodiment but, where applicable, are interchangeable and can be used in any selected embodiment even though such may not be specifically shown. [0031] Terms such as “upper”, “lower”, “inner”, “outer”, “inwardly”, “outwardly”, “vertical”, “horizontal”, and the like, when used herein, refer to the positions of the respective elements shown on the accompanying drawing figures and the present invention is not necessarily limited to such positions. [0032] It will thus be seen that the objects set forth above, among those elucidated in, or made apparent from, the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown on the accompanying drawing figures shall be interpreted as illustrative only and not in a limiting sense. [0033] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

In a preferred embodiment, an apparatus for automated magnetic separation of materials in laboratory trays, including: a frame upon an upper surface of which a multiwell laboratory tray may be placed; a base plate on which is mounted a plurality of upstanding magnets disposed below the upper surface; and apparatus to raise the base plate such as to insert the upstanding magnets into interwell spaces in the laboratory tray.

BACKGROUND [0001] A common environment scenario is mixed-mode, wherein differing versions of the same product, or software policy, are supported by various clients and/or remote servers. There are generally two kinds of product revisions: major and minor. A major revision generally results in a new set, or subset, of management interfaces and/or policy structure. A minor revision, in contrast, generally only entails the addition and/or modification of one or more fields and/or parameters of a management interface or policy structure of the software policy. Both major and minor product revisions, however, result in differing versions that are generally incompatible with prior versions, at least in so far as the changes to the product that resulted in the revision. [0002] In many mixed-mode environments there are also, or alternatively, differing client versions, i.e., differing operating systems supported by various clients, and/or differing supported platforms or platform versions that require alternative software product versions. [0003] Managing such mixed-mode environments presents unique challenges to computer-based system administrators and application developers attempting to query and control various clients simultaneously. For example, in currently known systems clients supporting a smaller major or minor version can not be queried with product versions with greater major and/or minor version values. This is generally because the lower version product hosted on any particular client is typically unable to interpret API (“application programming interface”) calls and/or policy parameters that are unique to the higher version product. [0004] As another example, currently known mixed-mode environment systems do not support the ability to push, or otherwise implement or deploy, software policies with minor version revisions to clients supporting the same major version but differing, smaller, minor versions. This is generally because smaller minor version products are typically unable to interpret policy parameters that are unique to the higher version product. [0005] The inability to implement one new product version in a mixed-mode environment can generate vast logistical and/or managerial challenges for system administrators who must keep track of which clients can, and do, support a particular new version software policy and which clients do not. The inability to implement one new product version in a mixed-mode environment can also result in workload, managerial and maintenance concerns for application developers who may be required to develop and maintain various versions of a product that can be used with differing client operating systems and/or differing client platforms. [0006] The inability to implement one new product version in a mixed-mode environment can also result in important system security problems, e.g., when dealing with products, such as, but not limited to, firewall policies, that are designed to address and/or otherwise enforce security policy in a system. [0007] Thus, it would be effective and efficient if a mixed-mode environment accommodated software policies of a greater major version managing clients supporting lesser major versions. It would likewise be effective and efficient if, in a mixed-mode environment, software policies of a greater minor version could be used to manage clients supporting lesser minor versions. Similarly, efficiencies could be gained in situations where software policies of a lesser major version could be used to manage clients maintaining greater major versions, and circumstances in which software policies of a lesser minor version could be used to manage clients supporting greater minor versions. [0008] It would also be beneficial if, in a mixed-mode environment, a software policy could be authored for and enforced on only a specific platform version or versions. Such version targeting will allow, among other things, a system administrator to push, or otherwise implement or deploy, a policy to a specific platform version or versions in order to address unique security issues faced by the respective platform version(s). Version targeting will also allow a system administrator to provide specific application enablement to respective platform version(s). SUMMARY [0009] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope ofthe claimed subject matter. [0010] Embodiments discussed herein include methodology for software version negotiation and for parameter stripping. In an embodiment a client of a system and a remote server of the system use software version negotiation to identify the policy version that will be used between them. In an aspect of this embodiment parameter stripping is employed as needed to handle minor version differences between the policy version identified to be used between a client and a remote server and the policy version of either the respective client or remote server. [0011] Embodiments discussed herein further include methodology for policy schema translation. In an embodiment a new policy version is translated, or otherwise converted, into one or more other policy versions of lesser value. In an embodiment the new policy version and the translated policy versions are deployed throughout the system to those clients that support the respective new policy version or any one translated policy version. [0012] Embodiments discussed herein also include methodology for version targeting. In an embodiment a deployment command includes one or more targeting parameters that each identifies a client version and/or client platform version for which a specific policy version is to be deployed. In an aspect of this embodiment unidentified client versions and/or client platform versions will not accept or, alternatively, use, or else be provided, the deployed policy version that the respective client version and/or client platform version supports. BRIEF DESCRIPTION OF THE DRAWINGS [0013] These and other features will now be described with reference to the drawings of certain embodiments and examples which are intended to illustrate and not to limit the invention, and in which: [0014] FIG. 1 is an embodiment managed environment system supporting mixed-modes, i.e., simultaneously supporting differing versions of the same software. [0015] FIG. 2 illustrates an embodiment logic flow for negotiating the software version to be used between a client and a remote server in a managed environment system. [0016] FIG. 3 depicts an exemplary warning message published to a user interface (UI) when a remote server supports a greater major version of software than the version hosted by a client in the managed environment system. [0017] FIG. 4 illustrates an embodiment logic flow for choosing the software version to be used between a client and a remote server. [0018] FIGS. 5A , 5 B, 5 C, 5 D and 5 E depict illustrative examples of selected software versions negotiated between a client and a remote server in a managed environment system. [0019] FIG. 6 depicts an embodiment process flow for negotiating the software version to be used between a client and a remote server in a managed environment system. [0020] FIGS. 7A and 7B illustrate an embodiment logic flow for parameter stripping an object command when the negotiated software minor version is less than the software minor version supported by the remote server processing the object command. [0021] FIG. 8 depicts an exemplary warning message published to a user interface (UI) when a remote server supports a greater minor version of software than the version hosted by a client in the managed environment system. [0022] FIGS. 9A and 9B illustrate examples of parameter stripping. [0023] FIG. 10 depicts an embodiment process flow for parameter stripping when the negotiated software minor version is less than the software minor version supported by a remote server in a managed environment system. [0024] FIG. 11 illustrates an embodiment logic flow for parameter stripping an object command when the negotiated software minor version is less than the software minor version supported by a management application of a client issuing the command. [0025] FIG. 12 depicts an embodiment process flow for parameter stripping when the negotiated software minor version is less than the software minor version supported by a management application of a client in a managed environment system. [0026] FIGS. 13A and 13B illustrate an embodiment logic flow for a methodology for implementing policy version negotiation and/or parameter stripping in a managed environment system. [0027] FIG. 14 illustrates an embodiment policy schema translation, or policy conversion. [0028] FIG. 15 depicts an example of an embodiment policy schema translation, or policy conversion. [0029] FIG. 16 depicts an example of an embodiment policy schema translation involving intermediate parameter stripping. [0030] FIG. 17 illustrates an embodiment logic flow for a methodology for policy schema translation, or policy conversion. [0031] FIG. 18 illustrates an embodiment logic flow for a methodology for deploying one or more policy versions to one or more clients in a managed environment system. [0032] FIG. 19 illustrates an example of a targeting parameter in an object command. [0033] FIG. 20 illustrates an embodiment logic flow for a methodology for version targeting during policy deployment. [0034] FIG. 21 is a block diagram of an exemplary basic computing device system that can process software, i.e., program code, or instructions. DETAILED DESCRIPTION [0035] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the invention. Any and all titles used throughout are for ease of explanation only and are not for use in limiting the invention. [0036] A simplified embodiment managed environment system 100 , depicted in FIG. 1 , can support utilizing management tools in a mixed-mode environment, i.e., an environment accommodating differing product, or policy, versions. An example of a product, or policy, with different versions is a firewall software program for providing secure computing environments. [0037] In the embodiment managed environment system 100 a management application (“mgmt app”) 105 can pass information and/or commands 130 to a client API 110 and receive infornation and/or commands 135 from the client API 110 . In an embodiment a mgmt app 105 and a client API 110 constitute a management console 150 . In an embodiment there can be one or more management consoles 150 in a managed environment system 100 . [0038] In the embodiment managed environment system 100 a client API 110 of a management console 150 can pass information and/or commands 140 to one or more remote servers 115 and receive information and/or commands 145 from one or more remote servers 115 . In an embodiment a host/process boundary 120 exists between the management console(s) 150 and the remote server(s) 115 . [0039] In an embodiment a mgmt app 105 is, or otherwise supports, a product, or policy, with its own particular product version. In an embodiment a remote server 115 can also support the same product, or policy. In an embodiment the version of any one product of, or otherwise supported by, a mgmt app 105 can be the same or can be different, i.e., is a different product revision, than the version of the same product supported by a remote server 115 . [0040] In an embodiment there are two kinds of product revisions: major and minor. In an embodiment a major product revision may result in a new set of management interfaces and/or policy structure. In an embodiment a minor product revision may result in the addition, deletion or modification of one or more fields or parameters of a policy rule of the product. [0041] In an embodiment product, or policy, versions are of the form x.y, where x indicates the major revision, or version, value and y indicates the minor revision, or version, value. In an embodiment larger numbers for x and y indicate a more current version than smaller numbers. Thus, for example, product, or policy, version 4.2 is more current than product, or policy, version 3.2 as version 4.2 has a larger major version value (4) than version 3.2 (with major version value 3). Likewise, product, or policy, version 4.2 is more current than product, or policy, version 4.1, even though both product versions have the same major version value (4), because version 4.2 has a larger minor version value (2) than version 4.1 (with minor version value 1). [0042] A major product revision may result in the addition of a new policy rule, or object, to a software product. Referring to FIG. 9A , rule 900 is an exemplary policy rule, or object, of a product with a version value 910 of 2.1. In this example policy rule 900 was added into the software product in version 2.0; policy rule 900 did not exist in any earlier version 1.x of the same product. [0043] In contrast, again for example, a minor product revision may result in the addition of a new parameter to an existing policy rule. Referring once more to FIG. 9A , parameter 905 (“LPORT”) exists in the policy rule 900 of version 910 (value 2.1), but is not a part of the same policy rule 920 of a different, earlier, minor version 925 (value 2.0) of the same product. [0044] In an embodiment each policy has a version value of the form x.y (major.minor version value). In an embodiment each rule, or object, of a policy also has a specific version value of the form x.y (major.minor version value). [0045] In an embodiment a managed environment system 100 contains a mgmt app 105 using a policy with a major version value that is greater than the major version value of the same policy maintained by a remote server 115 . In an embodiment a managed environment system 100 contains a mgmt app 105 using a policy with a major version value that is less than the major version value of the same policy maintained by a remote server 115 . [0046] In an embodiment a managed environment system 100 supports a mgmt app 105 using a policy with the same major version value as the major version value of the same policy maintained by a remote server 115 , but with a minor version value that is greater than the minor version value of the policy maintained by the remote server 115 . In an embodiment a managed environment system 100 supports a mgmt app 105 using a policy with the same major version value as the major version value of the policy maintained by a remote server 115 , but with a minor version value that is less than the minor version value of the policy maintained by the remote server 115 . [0047] In an embodiment a managed environment system 100 contains a mgmt app 105 using a policy with the same major version value as the major version value of the policy maintained by a remote server 115 and with the same minor version value as the minor version value of the policy maintained by the remote server 115 . [0048] FIG. 2 illustrates an embodiment logic flow for a methodology for software version. negotiation. While the following discussion is made with respect to systems portrayed herein, the operations described may be implemented in other systems. Further, the operations described herein are not limited to the order shown. Additionally, in other alternative embodiments more or fewer operations may be performed. [0049] In an embodiment the mgmt app sends a request to its corresponding client API to open a remote policy store and request the policy version maintained by a particular remote server 200 . In an embodiment the client API then sends a request to the remote server for its supported policy version 205 . In an embodiment the remote server retrieves and returns its supported policy version to the client API 210 . In an embodiment the client API chooses the policy version to be used between the policy version maintained by the mgmt app and the policy version hosted by the remote server 215 . In an embodiment the client API then opens the remote policy store and passes the chosen policy version value to be used to the remote server 220 . [0050] In an embodiment the remote server stores the chosen policy version value selected by the client API and passes the appropriate policy handle back to the client API 225 . In an embodiment a policy handle references a corresponding policy object and allows a local or remote application that utilizes the policy management APIs to identify and manipulate the policy objects on a specified host, i.e., on a specified computing platform. In an embodiment a policy object can be any policy store, i.e., set of policy rules that govern the implementation of a particular policy of a software program or package, such as, but not limited to, a firewall policy store, an IPsec rule store, etc. In an embodiment a policy object can also, or otherwise, be a subset of a policy store, i.e., one or more rules of a set of policy rules. [0051] In an embodiment the client API stores the policy handle received from the remote server 230 . In an embodiment the client API forwards the policy handle received from the remote server to the mgmt app 235 . [0052] In an embodiment at decision block 240 the mgmt app determines whether the policy major version value supported by the mgmt app is less than the policy major version value maintained by the remote server. If the mgmt app's policy major version value is less than that of the policy major version value maintained by the remote server, in an embodiment the mgmt app publishes a warning message to the user interface that parts of the policy will be completely ignored 245 . In an embodiment the policy parts that will be completely ignored are those policy objects, or rules, that exist in the remote server's policy version but are not supported by the mgmt app's policy version. [0053] In an embodiment the logic flow for software version negotiation is finalized 250 . [0054] FIG. 3 depicts an embodiment exemplary warning message 300 published by a mgmt app 105 when its policy major version value is less than the major version value of the policy supported by a remote server 115 . The embodiment warning message 300 includes text 305 that indicates that the remote server's policy version has some elements, or objects or rules, that are not valid, i.e., are not supported, in the mgmt app's policy version and therefore, some portions of the remote server's policy version are completely ignored during execution, or implementation. [0055] In an embodiment the warning message 300 contains an “OK” button 310 that a user must click on, or otherwise activate, to acknowledge that the user has seen the warning message 300 . [0056] Referring back to decision block 240 of FIG. 2 , in an alternative embodiment, if the mgmt app's policy major version value is determined to be greater than that of the major version value of the same policy maintained by the remote server the mgmt app will publish a warning message to the user interface. In an aspect of this alternative embodiment the published warning message in this situation indicates that the remote server's policy version does not support some elements, or objects or rules, of the policy and that these unsupported policy rules are ignored during policy execution, or implementation. [0057] In an embodiment, if the mgmt app's policy major version value is the same as the remote server's policy major version value, all rules of the respective policy version are supported and will be implemented. However, in this situation all aspects, i.e., parameters, of the policy may not be implemented, depending on the policy minor versions supported respectively by the mgmt app 105 and the remote server 115 . [0058] FIG. 4 illustrates an embodiment logic flow for a methodology for a client API to choose the policy version 215 to be used between a mgmt app 105 and a remote server 115 . While the following discussion is made with respect to systems portrayed herein, the operations described may be implemented in other systems. Further, the operations described herein are not limited to the order shown. Additionally, in other alternative embodiments more or fewer operations may be performed. [0059] At decision block 400 of FIG. 4 a determination is made as to whether the same policy major version is maintained by the mgmt app and the remote server. If no, the client API chooses the policy version with the lower major version value, and its corresponding minor version, to be used 405 . [0060] Referring to FIG. 5A , as an example 500 , if the mgmt app's policy version 502 is 4 . 2 and the remote server's policy version 504 is 3.7, the mgmt app 105 and the remote server 115 support different policy major versions, and in an embodiment the client API 110 will choose the policy with the lower major version value (3), and its corresponding minor version (7), to be used. Thus in example 500 policy version 504 maintained by the remote server 115 , value 3.7, will be chosen by the client API 110 to be used. [0061] As another example 510 depicted in FIG. 5B , if the mgmt app's policy version 512 is 4.1 and the remote server's policy version 514 is 5.3, the mgmt app 105 and the remote server 115 again support different policy major versions, and in an embodiment the client API 110 will choose the policy with the lower major version value (4), and its corresponding minor version (1), to be used. Thus in example 510 policy version 512 maintained by the mgmt app 105 , value 4.1, will be chosen by the client API 110 to be used. [0062] When the client API 110 must choose the policy version with the lower major version value between the mgmt app's policy version and the remote server's policy version, the policy can still be used to manage one or more remote clients associated with the remote server. In this situation, however, one or more objects, or elements, or rules, of the policy with the higher major version value will be ignored in policy execution, or implementation. [0063] Referring again to FIG. 4 , if the same major version of the policy is supported by both the mgmt app and the remote server, at decision block 410 a determination is made as to whether the mgmt app and the remote server maintain the same minor version of the policy. If no, the client API chooses the policy with the lower minor version value to be used 420 . [0064] Referring to FIG. 5C , as an example 520 , if the mgmt app's policy version 522 is 2.8 and the remote server's policy version 524 is 2.7, the mgmt app 105 and the remote server 115 support the same policy major version (2) but different policy minor versions. In this embodiment example 520 the client API 110 will choose the lower policy minor version (7) to be used. Thus, in example 520 the policy version 524 maintained by the remote server 115 , value 2.7, will be chosen by the client API 110 to be used. [0065] As another example 530 of FIG. 5D , if the mgmt app's policy version 532 is 3.4 and the remote server's policy version 534 is 3.8, the mgmt app 105 and the remote server 115 again support the same policy major version (3) but differing policy minor versions. In this embodiment example 530 the client API 110 will choose the lower policy minor version (4) to be used. In example 530 therefore, the policy version 532 maintained by the mgmt app 105 , value 3.4, will be chosen by the client API 110 to be used. [0066] When the client API 110 must choose the policy with the lower minor version value between the mgmt app's policy version and the remote server's policy version, all objects, or elements, or rules, of the policy version supported by both the mgmt app 105 and the remote server 115 will be used. However, one or more parameters of one or more objects supported in the higher valued minor version will be ignored in policy execution, or implementation. [0067] Referring once again to FIG. 4 , at decision block 410 if a determination is made that the same policy minor version is maintained by the mgmt app and the remote server the mgmt app and the remote server support the same policy major/minor version x.y. This same policy major/minor version x.y is the version chosen by the client API to be used 415 . Under these conditions all objects, or elements, or rules, of the policy version supported by both the mgmt app 105 and the remote server 115 will be used and no parameter stripping is necessary. [0068] Referring to FIG. 5E , as an example 540 of the same policy major/minor version being supported by the mgmt app 105 and the remote server 115 , the mgmt app's policy version 542 is 7.1 and the remote server's policy version 544 is also 7.1. In this embodiment situation the client API 110 chooses the policy major/minor version 546 supported by both the mgmt app 105 and the remote server 115 , value 7.1, to be used. [0069] FIG. 6 is an embodiment processing flow for software version negotiation, i.e., for identifying the policy version to be used between a mgmt app 105 and a remote server 115 . In an embodiment the mgmt app 105 sends a request 605 to its corresponding client API 110 to open a remote policy store. In an embodiment request 605 is an OPENPOLICYSTORE call. In an embodiment request 605 includes as a parameter the mgmt app's supported policy major/minor version value 660 . [0070] In an embodiment, upon receiving the request 605 the client API 110 sends a request 610 to a remote server 115 for the remote server 115 to identify its corresponding policy major/minor version. In an embodiment request 610 is a GETSUPPORTEDPOLICYVERSION call. [0071] In an embodiment, upon receiving the request 610 the remote server 115 identifies the requested policy version and passes this policy version value 615 back to the client API 110 . In an embodiment, upon receiving the policy version value 615 maintained by the remote server 115 , the client API 110 compares the remote server's policy version value with the policy version value supplied by the mgmt app 105 . In an embodiment the client API 110 chooses the policy version value 640 to be implemented. In an aspect of this embodiment the client API 110 chooses the lower, or smaller, policy version value if one of the policy versions supported by the mgmt app 105 and the remote server 115 is a lesser value than the other. [0072] In an embodiment, after the client API 110 chooses the policy version value to be implemented the client API 110 sends a request 620 to the remote server 115 for the remote server 115 to open its remote policy store. In an embodiment request 620 is an OPENPOLICYSTORE call. In an embodiment request 620 includes as a parameter 665 the value ofthe policy major/minor version chosen by the client API 110 to be implemented. [0073] In an embodiment, upon receiving the request 620 the remote server 115 stores the chosen policy major/minor version 645 . In an embodiment, after receiving the request 620 the remote server 115 passes the appropriate policy handle 630 for the chosen policy version to the client API 110 . In an embodiment the client API 110 stores the policy handle 650 received from the remote server 115 . [0074] In an embodiment the client API 110 then forwards the received policy handle 630 to the mgmt app 105 . In an embodiment the mgmt app 105 stores the policy handle 655 received from the client API 110 . [0075] Once a policy version has been negotiated, or otherwise chosen or identified, the embodiment managed environment system 100 , when acting on an object command, determines if parameter stripping is necessary. Embodiment object commands include, but are not limited to, enumerate (or read), add, set, and delete. [0076] In an embodiment parameter stripping is performed, as necessary, when the policy minor version value supported by a remote server 115 is of a different value than the corresponding policy minor version value supported by a mgmt app 105 issuing a policy object command to the remote server 115 . [0077] In an embodiment the mgmt app 105 of a management console 150 does not perform parameter stripping. In an embodiment, if a remote server 115 maintains a policy with a greater minor version value than the corresponding policy maintained by a mgmt app 105 and the mgmt app 105 issues an object command to the remote server 115 that necessitates the remote server 115 forwarding one or more objects to the mgmt app 105 , e.g., an enumerate (or “enum”) object command, the remote server 115 will check for, and as necessary, perform parameter stripping. In an embodiment, if a mgmt app 105 maintains a policy with a greater minor version value than the corresponding policy maintained by a remote server 114 and the mgmt app 105 issues an object command to the remote server 115 that includes the forwarding of one or more objects to the remote server 15 , e.g., an add object command, then the client API 110 associated with the mgmt app 105 will check for, and as necessary, perform parameter stripping. [0078] FIGS. 7A and 7B illustrate an embodiment logic flow for a methodology for parameter stripping when the policy minor version supported by a remote server 115 has a larger value than the corresponding policy minor version supported by a mgmt app 105 . While the following discussion is made with respect to systems portrayed herein, the operations described may be implemented in other systems. Further, the operations described herein are not limited to the order shown. Additionally, in other alternative embodiments more or fewer operations may be performed. [0079] Referring to FIG. 7A , in an embodiment a mgmt app of a management console issues a command 700 which is forwarded to the client API of the management console. In the logic flow of FIGS. 7A and 7B the command issued by the mgmt app requires a remote server to forward one or more objects to the mgmt app, e.g., an enum command which requests a list of all the objects of a specified policy. In an embodiment the client API forwards the command from the mgmt app to the appropriate remote server 705 . [0080] As discussed, in an embodiment each object, or element or rule, of a policy has its own specific version value. Thus, in an embodiment, upon receiving the command from the client API the remote server gets a first, current, object of the respective policy 710 that is responsive to the command, and at decision block 715 makes a determination if the current object's version is greater than the policy handle's version which reflects the chosen policy version to be implemented. If no, parameter stripping is not necessary for this current object and the remote server determines at decision block 725 whether all the objects of the policy responsive to the command have been checked for potential parameter stripping. [0081] If, however, the current object's version is greater than the policy handle's version, the remote server strips the parameters from the current object that do not exist, or are otherwise not supported, in the policy handle's version 720 . The remote server than determines at decision block 725 whether all the objects of the policy responsive to the command have been checked for potential parameter stripping. [0082] If there are remaining objects to be checked for possible parameter stripping the remote server gets the next, new current, object of the policy 730 and returns to decision block 715 to determine whether the now current object's version is greater than the policy handle's version. [0083] Once all appropriate policy objects have been checked for potential parameter stripping, in an embodiment the remote server passes the objects responsive to the mgmt app's command to the client API 735 . For example, if the mgmt app issued an enum command for a particular policy the remote server now passes all the objects of the policy to the client API 735 . In this embodiment, if an object responsive to the command required parameter stripping the remote server passes the parameter stripped version of the object to the client API 735 . [0084] In an embodiment the remote server includes with the object(s) sent to the client API an identification of each object's status 735 . In an embodiment an object's status indicates whether or not the object was parameter stripped. [0085] In an embodiment the remote server includes with the object(s) sent to the client API an error code 735 . In an embodiment the error code indicates the status of the implementation of the mgmt app command, e.g., command ran successfully, command failed, etc. [0086] In an embodiment the client API passes the objects received from the remote server to the mgmt app 740 . In an embodiment the client API also passes each object's status received from the remote server to the mgmt app 740 . In an embodiment the client API passes the error code received from the remote server to the mgmt app 740 . [0087] At decision block 745 the mgmt app makes a determination based on the various objects' status whether parameter stripping was performed on one or more policy objects. If yes, as shown in FIG. 7B , the mgmt app publishes a warning message to the user interface (UI) indicating that one or more parameters in one or more of the policy objects in the version supported by the remote server are not valid in the respective policy version supported by the mgmt app 750 . In an aspect of this embodiment the warning message also indicates that one or more portions of the remote policy version are, therefore, partially ignored 750 . [0088] In an embodiment the mgmt app also, or otherwise, uses the received error code to compose and publish a message to the UI indicating the status of the command processing 755 , i.e., a command processing status message. In an aspect of this embodiment the mgmt app only publishes a command processing status message if the command failed to process completely and/or correctly. [0089] Whether or not any warning message is published, thereafter the processing of the current command is finalized 760 . [0090] FIG. 8 depicts an embodiment exemplary warning message 800 published by a mgmt app 105 when its policy minor version value is less than the minor version value of the policy supported by a remote server 115 . The embodiment warning message 800 includes text 805 that indicates that the remote server's policy version has one or more objects that have one or more parameters that are not valid, i.e., are not supported, in the mgmt app's policy version and therefore, some portions of the remote server's policy version are partially ignored during policy execution, or implementation. [0091] In an embodiment the warning message 800 contains an “OK” button 810 that a user must click on, or otherwise activate, to acknowledge the user has seen the warning message 800 . [0092] An example of parameter stripping when the policy handle minor version is different than the policy minor version supported by a remote server 115 is depicted in FIG. 9A . In FIG. 9A assume that a mgmt app 105 is attempting to enumerate, or read, from a remote server 115 the objects, or rules, of a policy that in the remote server's policy version contain object, or rule, 900 with an object version value 910 of 2.1. Also assume the policy handle version value, i.e., the policy version chosen by the client API 110 during software version negotiation, and the policy version supported by the mgmt app 105 , has a value of 2.0. In this example the mgmt app's policy minor version value (0), and the resultant policy handle's minor version value (0), for object, or rule, 920 of FIG. 9A is less than the corresponding remote server's policy minor version value (1) for the corresponding object 900 . [0093] In the example of FIG. 9A , object 900 , version 910 of a value 2.1, has an additional, local port value, parameter 905 that does not exist, and is therefore not supported, in the corresponding object 920 , version 925 of a value 2.0. Thus, in this example parameter stripping is required to strip, or otherwise delete, parameter 905 (LPORT=2869) from object 900 . As shown in the corresponding object, or rule, 920 , all other parameters that exist in object 900 remain after parameter stripping. [0094] In the example of FIG. 9A , assuming a mgmt app 105 is attempting to enumerate the policy objects from a remote server 115 wherein the mgmt app's minor policy version is smaller than the remote server's corresponding minor policy version, the remote server 115 performs the parameter stripping as necessary. [0095] FIG. 9B depicts a second example of parameter stripping when the policy handle minor version is different than the policy minor version supported by the remote server 115 . In FIG. 9B assume that a mgmt app 105 is attempting to enumerate, or read, from a remote server 115 the objects, or rules, of a policy that in the remote server's policy version contain object, or rule, 930 with an object version value 940 of 3.1. Also assume the policy handle version value, i.e., the policy version chosen by the client API 110 during software version negotiation, and the policy version supported by the mgmt app 105 , has a value of 3.0. In this example the mgmt app's policy minor version value (0), and the resultant policy handle's minor version value (0), for object, or rule, 950 of FIG. 9B is less than the corresponding remote server's policy minor version value (1) for the corresponding object 930 . [0096] In the example of FIG. 9B object 930 , version 940 of a value 3.1, has an additional, application version value, parameter 935 that does not exist, and is therefore not supported, in the corresponding object 950 , version 955 .of a value 3.0. Thus, in this example parameter stripping is required to strip, or otherwise delete, parameter 935 (APPVER=6.*) from object 930 . As shown in the corresponding object, or rule, 950 , all other parameters that exist in object 930 remain after parameter stripping. [0097] In the example of FIG. 9B , assuming a mgmt app 105 is attempting to enumerate the policy objects from a remote server 115 wherein the mgmt app's minor policy version is smaller than the remote server's corresponding minor policy version, the remote server 115 performs the parameter stripping as necessary. [0098] FIG. 10 is an exemplary embodiment processing flow for an object command issued from a mgmt app 105 to a remote server 115 . In the example of FIG. 10 the applicable policy minor version value supported by the mgmt app 105 is less than the minor version value of the corresponding policy supported by the remote server 115 . In the example of FIG. 10 the issued object command requires the remote server 115 to send one or more objects to the mgmt app 105 , e.g., an enum object command. [0099] In the example and embodiment of FIG. 10 the mgmt app 105 sends an object command 1005 to the client API 110 for forwarding to a remote server 115 . In this example command 1005 is an enum command with an ENUM OBJECTS call. In an embodiment command 1005 includes a handle parameter 1010 that identifies the policy and policy version for which the mgmt app 105 is issuing the enum command 1005 . [0100] In an embodiment, upon receiving the command 1005 from the mgmt app 105 the client API 110 forwards the command 1005 to the appropriate remote server 115 for processing. [0101] In an embodiment, upon receiving the command 1005 the remote server 115 checks 1025 each object, or rule, of the identified policy responsive to the command 1005 to determine if the object version supported by the remote server 115 has a minor version value that is larger than the minor version value of the indicated policy handle parameter 1010 . For any one such object, or rule, checked 1025 , if the remote server's minor version value is larger than the policy handle minor version value, the remote server strips out, or otherwise deletes, 1025 any parameter, or parameters, in its object version that do not exist in the policy handle's version. [0102] In an embodiment, after the remote server 115 has checked 1025 all the objects, or rules, of the identified policy responsive to the command 1005 , the remote server 115 sends a list of the policy objects 1015 to the client API 110 . In an embodiment the list of policy objects 1015 sent to the client API 110 identifies each object, or rule, in the policy. [0103] In an embodiment the remote server 115 accompanies the list of policy objects 1015 sent to the client API 110 with each object's status 1030 . In an embodiment an object's status 1030 indicates whether or not the object was modified, i.e., had parameter stripping performed on it, by the remote server 115 . [0104] In an embodiment the remote server 115 accompanies the list of policy objects 1015 sent to the client API 110 with an error code 1035 . In an embodiment the error code 1035 indicates the status of the command processing, e.g., the command processed successfully, the command failed to be executed, etc. [0105] In an embodiment, upon receiving the list of policy objects 1015 from the remote server 115 the client API 110 forwards the object list 1015 to the mgmt app 105 . In an embodiment the client API 110 forwards with the object list 1015 to the mgmt app 105 each object's status 1030 . In an embodiment the client API 110 forwards with the object list 1015 to the mgmt app 105 the error code 1035 received from the remote server 115 . [0106] In an alternative embodiment, after receiving the list of policy objects 1015 from the remote server 115 the client API 110 generates a new message, e.g., an identification of the policy objects in a new format, a message with additional and/or different information than that sent with the list of policy objects 1015 from the remote server 115 to the client API 110 , etc., and passes the newly generated message to the mgmt app 105 . [0107] In an embodiment, after receiving the list of policy objects 1015 from the client API 110 the mgmt app 105 can, if warranted, provide a warning message to the user interface 1020 indicating that some portions of the remote server's policy version are partially ignored during implementation. In an embodiment the mgmt app 105 uses the received objects' status 1030 to determine if parameter stripping was performed on any objects and, if so, to compose and issue an appropriate warning message to the user interface 1020 . [0108] In an embodiment the mgmt app 105 can use the error code to also, or otherwise, compose and issue a warning message to the user interface that indicates the status of the command processing, i.e., a command processing status message. In an aspect of this embodiment the mgmt app only publishes a command processing status message if the command failed to process completely and/or correctly. [0109] As previously noted, in an embodiment, if a mgmt app 105 maintains a policy that has a greater minor version value than the corresponding policy maintained by a remote server 115 and the mgmt app 105 issues an object command to the remote server 115 that includes the forwarding of one or more objects to the remote server 115 , e.g., an add object command, then the client API 110 associated with the mgmt app 105 will check for, and as necessary, perform parameter stripping. [0110] FIG. 11 illustrates an embodiment logic flow for a methodology for necessary parameter stripping when the policy minor version supported by a mgmt app 105 is of a larger value than the corresponding policy minor version supported by a remote server 115 . While the following discussion is made with respect to systems portrayed herein, the operations described may be implemented in other systems. Further, the operations described herein are not limited to the order shown. Additionally, in other alternative embodiments more or fewer operations may be performed. [0111] In an embodiment a mgmt app of a management console issues a command 1100 which is forwarded to the client API of the management console. In the logic flow of FIG. 11 the command issued by the mgmt app includes an object to be processed by a remote server, e.g., an add command which requests the remote server add a specified object to a policy, or a set command which requests the remote server set a parameter in a specified object to an indicated value. In an embodiment the command issued by the mgmt app 1100 includes the object to be operated on by the remote server and the object's version value. [0112] In an embodiment the command issued by the mgmt app includes the policy handle associated with the passed object. [0113] In an embodiment, upon receiving the command from the mgmt app, at decision block 1105 the client API checks if the passed object's minor version value is greater than the policy handle's minor version value. If yes, the client API strips from the object all those parameters that do not exist in the object of the corresponding policy handle's version 1110 . [0114] Whether or not parameter stripping is required, the client API thereafter forwards the command and object to the remote server for processing 1115 . If the object had parameter stripping performed on it by the client API, the client API forwards the stripped version of the object to the remote server for processing 1115 . The remote server then implements, or otherwise processes, the command 1120 , and forwards an error code back to the client API 1125 . In an embodiment the error code indicates the status of the command processing, e.g., command processed successfully, command failed to process, etc. [0115] In an embodiment the client API forwards the received error code from the remote server to the mgmt app 1130 . In an embodiment the client API forwards with the error code to the mgmt app a status of the object that was a parameter in the mgmt app's command 1130 . In an embodiment the object's status indicates whether or not the object required parameter stripping. [0116] In an embodiment at decision block 1135 the mgmt app makes a determination based on the object status whether parameter stripping was performed on the command object. If yes, the mgmt app composes and publishes a warning message to the user interface (UI) indicating that one or more parameters of the object supported by the mgmt app were not implemented because they were not supported by the applicable remote server 1140 . [0117] In an embodiment the mgmt app also, or otherwise, uses the received error code to compose and publish a message to the UI indicating the status of the command processing 1145 , i.e., a command processing status message. In an aspect of this embodiment the mgmt app only publishes a command processing status message if the command failed to process completely and/or correctly. [0118] Whether or not any warning message is published, thereafter the processing of the current mgmt app command is finalized 1150 . [0119] In an embodiment the mgmt app 105 can issue a command to a remote server 115 that includes more than one object parameter. In this embodiment, if any object version supported by the mgmt app 105 has a greater minor value than the respective object version supported by the remote server 115 , the client API 110 of the management console 150 will check the respective object and perform parameter stripping on the object as necessary. [0120] FIG. 12 is an exemplary embodiment processing flow for a command issued from a mgmt app 105 to a remote server 115 . In the example of FIG. 12 the applicable policy minor version value supported by the remote server 115 is less than the minor version value of the corresponding policy supported by the mgmt app 105 . In the example of FIG. 12 the issued command includes one or more object parameters that the remote server 115 must utilize in processing the command, e.g., an add object command or a set object command. [0121] In the example and embodiment of FIG. 12 the mgmt app 105 sends a command 1205 to the client API 110 for forwarding to a remote server 115 . In this example command 1205 is an add object command with an ADDOBJECT call. In an embodiment command 1205 includes a policy handle parameter 1240 that identifies the negotiated policy and policy version for which the mgmt app 105 is issuing the add command 1205 . [0122] In an embodiment command 1205 includes one or more object parameters 1245 that are to be utilized in processing the command 1205 . In an embodiment command 1205 includes an object version identification 1250 for each object parameter 1245 . [0123] In an embodiment, upon receiving the command 1205 from the mgmt app 105 the client API 110 checks 1230 to determine for each object parameter of the command whether the object minor version value is greater than the policy handle minor version value. For any object parameter checked 1230 , if the object's minor version value is larger than the policy handle minor version value, the client API 110 strips out, or otherwise deletes, 1230 any parameter, or parameters, in the object passed by the mgmt app 105 in the command call 1205 that do not exist in the corresponding object in the policy handle's version. [0124] In an embodiment, after the client API checks 1230 all the object parameters, it forwards the command 1210 to the remote server 115 . In this example of FIG. 12 command 1210 is the add object command, i.e., is an ADDOBJECT call. In an embodiment command 1210 includes the policy handle parameter 1240 passed in the command call 1205 from the mgmt app 105 to the client API 110 . [0125] In an embodiment command 1210 includes one or more object parameters 1255 that are to be utilized in processing the command 1210 . If any object parameter 1245 in the mgmt app command call 1205 had parameter stripping performed on it by the client API 110 , the parameter stripped version of the object is included in the command call 1210 from the client API 110 to the remote server 115 . [0126] In an embodiment command 1210 includes an object version identification 1260 for each object parameter 1255 . If an object parameter 1245 in the mgmt app command 1205 had parameter stripping performed on it by the client API 110 , the respective object version parameter 1260 in the command 1210 reflects the stripped object version. [0127] After receiving the command 1210 from the client API 110 the remote server 115 attempts to process the command 1225 , e.g., add the specified object(s) indicated in the add object command to the policy. Thereafter, in an embodiment the remote server 115 forwards an error code 1215 to the client API 110 . In an embodiment the error code 1215 indicates the status of the command processing, e.g., the command processed successfully, the command failed to be executed, etc. [0128] In an embodiment, upon receiving the error code 1215 from the remote server 115 , the client API 110 forwards the error code 1215 to the mgmt app 105 . In an embodiment the client API 110 accompanies the error code 1215 sent to the mgmt app 105 with an object status 1220 for each object parameter in the mgmt app's command 1205 . In an embodiment an object's status 1220 indicates whether or not the object was modified, i.e., had parameter stripping performed on it, by the client API 110 . [0129] In an embodiment the mgmt app 105 uses the received objects' status 1220 to determine if parameter stripping was performed on any object and, if so, to compose and issue an appropriate warning message to the user interface 1235 . [0130] In an embodiment the mgmt app 105 can use the error code 1215 to also, or otherwise, compose and issue a warning message to the user interface that indicates the status of the command processing, i.e., a command processing status message. In an aspect of this embodiment the mgmt app 105 only publishes a command processing status message if the command failed to process completely and/or correctly. [0131] FIGS. 13A and 13B illustrate an embodiment logic flow for a methodology for implementing policy version negotiation and/or parameter stripping in a managed environment system 100 . While the following discussion is made with respect to systems portrayed herein, the operations described may be implemented in other systems. Further, the operations described herein are not limited to the order shown. Additionally, in other alternative embodiments more or fewer operations may be performed. [0132] In an embodiment a mgmt app of a management console and a remote server will negotiate a policy version to be used 1300 . In an embodiment the version with the lowest major version value is negotiated to be used, and thereafter deemed the policy handle 1300 . An embodiment methodology for software, or policy, version negotiation is shown in FIG. 2 and FIG. 4 . [0133] At decision block 1305 a determination is made as to whether the policy version supported by the mgmt app has the same major/minor version value x.y as the policy version supported by the remote server. If the mgmt app and the remote server do support the identical policy major/minor version x.y, then when commands are issued from the mgmt app for this policy no policy objects will be ignored and no object parameters will be stripped to process the command 1310 . [0134] If, however, the mgmt app and the remote server do not support the same policy major/minor version, then at decision block 1315 a determination is made as to whether the policy version supported by the mgmt app is the same as the negotiated policy handle's version 1315 . If yes, the mgmt app policy version value is less than the remote server's corresponding policy version value and the negotiated policy version is the mgmt app's policy version. [0135] If the mgmt app's policy version is the negotiated policy version, i.e., policy handle, then at decision block 1320 a determination is made as to whether the remote server's policy major version value x is greater than the negotiated policy major version value x. If yes, the remote server will use the smaller, negotiated, major/minor policy version in processing all the mgmt app commands for the policy 1325 . [0136] If the remote server's policy major version value is not greater than the negotiated policy major version value the remote server's policy minor version value y is greater than the negotiated policy minor version value y. In this case parameter stripping may be required. [0137] At decision block 1330 a determination is made as to whether the current issued mgmt app command includes one or more objects to be processed by the remote server. Thus, at decision block 1330 a determination is made as to whether the current command issued by the mgmt app to the remote server includes one or more object parameters. If yes, nothing need be done 1335 because the mgmt app is using a smaller policy version than the remote server, and all parameters known in the smaller policy version are known in the larger, remote server's, policy version. Thus, in this case parameter stripping is not required. [0138] If, however, at decision block 1330 a determination is made that the current mgmt app command does not include one or more object parameters, at decision block 1340 a determination is made as to whether the current mgmt app command expects one or more objects to be passed from the remote server in response. If no, nothing need be done, i.e., parameter stripping is not required, 1345 as there is no response expected from the remote server that will include any objects that the mgmt app's policy version will not recognize. [0139] If, however, at decision block 1340 a determination is made that the current mgmt app command expects one or more objects to be passed from the remote server in response, the remote server will check for and strip all necessary parameters from the objects that are responsive to the mgmt app's command 1350 . An embodiment methodology for parameter stripping in this instance is shown in FIGS. 7A and 7B . [0140] Referring back to decision block 1315 , if a determination is made that the mgmt app policy version is not the negotiated policy version, then the mgmt app's policy version value is greater than the remote server's and negotiated policy's version value. In this case, and referring to FIG. 13B , at decision block 1355 a determination is made as to whether the mgmt app's policy major version value x is greater than the negotiated policy major version value x. If yes, the mgmt app will use the smaller, negotiated, major/minor policy version in processing all the mgmt app commands for the policy 1360 . [0141] If the mgmt app's policy major version value is not greater than the negotiated policy major version value the mgmt app's policy minor version value y is greater than the negotiated policy minor version value y. In this case parameter stripping may be required. [0142] At decision block 1365 a determination is made as to whether the current mgmt app command expects one or more objects to be passed from the remote server in response. If yes, nothing need be done, i.e., parameter stripping is not required, 1370 as there is no response expected from the remote server that will include any objects that the mgmt app's policy version will not recognize. [0143] If, however, at decision block 1365 a determination is made that the current mgmt app command does not expect one or more objects to be passed from the remote server in response, then at decision block 1375 a determination is made as to whether the current mgmt app command includes one or more object parameters to be processed by the remote server. If no, nothing need be done, i.e., parameter stripping is not required, 1385 as the mgmt app is not passing any objects to the remote server that the remote server's policy version will not recognize. [0144] At decision block 1375 if a determination is made that the current mgmt app command does include one or more objects to be processed by the remote server the client API associated with the mgmt app will check for and strip all necessary parameters from the objects 1380 . Checking for, and stripping as necessary, parameters in the passed objects of the mgmit app command is necessary in this instance for those object parameters that do not exist in the remote server's smaller policy version. An embodiment methodology for parameter stripping in these circumstances is shown in FIG. 11 . [0145] In an embodiment a mgmt app of a particular version can be implemented on an older system in which the respective client API 110 is of a smaller version, i.e., the client API 110 version is older, or less than, the current version of the mgmt app 105 of the management console 150 . In this embodiment a remote server 115 interfacing with the respective management console 150 supports a different version than the mgmt app 105 or the client API 110 . In this embodiment situation the client API 110 negotiates, or otherwise chooses, the smallest version between the mgmt app 105 's version, the client API 110 's version and the remote server 115 's version to be the version implemented between these three. Multi-Version Policy Implemenation [0146] In some situations it can be advantageous to deploy more than one version of a policy to support managing group policy objects (“GPO”). In circumstances where various clients in a managed environment system I 00 support various versions, it is advantageous to deploy policy versions to these clients that are each compatible with the respective client-supported major version, i.e., perform policy schema translation. Moreover, in combination with policy schema translation, it is advantageous to use parameter stripping to handle differences in minor policy versions. [0147] In an embodiment, using policy schema translation to generate policy versions for deployment to various clients in a managed environment system 100 allows for a single policy containing new features to be authored using the latest version of the host management console, or client. The new policy version is translated to policy versions that can be implemented on other clients in the managed environment system 100 . In this manner, no more than one policy version need be authored to support the implementation of the policy with various alternative client versions and/or client platform versions. [0148] Referring to FIG. 14 , in an embodiment a schema translation engine 1425 is used to translate a new policy version 1405 into P different versions 1415 . In an embodiment P represents one (1) less than the major version number of the policy 1405 native to the schema translation engine 1425 . For example, if a policy 1405 to be deployed has a version value of 4.w, in an embodiment the respective schema translation engine 1425 will translate the policy into three (3) versions 1415 as three (3) is one (1) less than the major version value four (4) of the policy 1405 . [0149] Thus, if the new policy version 1405 to be translated has a value of 4.w, in an embodiment the schema translation engine 1425 will generate a version 3.x, a version 2.y and a version 1.z of the policy. [0150] In an embodiment each P translated minor version represents the highest, or largest, minor version for each P major version. Thus, for example, if eight (8) is the largest known minor version for major version three (3), then in an embodiment the new policy 1405 version 4.w will be translated into version 3.8. [0151] In an alternate embodiment each P translated minor version represents a known minor version corresponding to the P major version value. As an example, in this alternate embodiment new policy 1405 version 4.w may be translated into version 3.6 even though version 3.8 is the largest existing version with a major version value of three (3). [0152] In another alternate embodiment policy schema translation is performed on a policy with a new major version value to produce Q number of translated versions where Q is less than the value of the new policy's major version minus one (1). As an example, in this alternate embodiment new policy 1405 version 4.w may be translated into only two (2) versions, 3.x and 2.y. [0153] In an embodiment the schema translation engine 1425 is run by the client API 110 of the management console 150 implementing the new major policy version 1405 . In an embodiment policy schema translation is performed at policy deployment time. [0154] In an embodiment a schema translation engine 1425 interprets a translation collection 1410 to generate the one or more translated policy versions 1415 . In an embodiment the translation collection 1410 can be dynamically updated to provide the most efficient and secure output policy for a managed environment system 100 . [0155] In an embodiment in some circumstances the translation engine 1425 may translate a single rule of a new policy version 1405 to multiple rules in an older, or earlier, policy version in order to achieve the desired version result. [0156] In an embodiment, and referring to the example of FIG. 14 , to deploy a new major policy version to various clients, or management consoles, of a managed environment system 100 , the schema translation engine 1425 hosted on management console 1450 supporting the new policy version 1405 interprets a translation collection 1410 to translate the policy 1405 version 4.w to version 3.x, which represents the highest existing minor version x for major version three (3). In this embodiment example the schema translation engine 1425 interprets the translation collection 1410 to translate the policy version 3.x to version 2.y, which represents the highest existing minor version y for major version two (2). In this embodiment example the schema translation engine 1425 interprets the translation collection 1410 to translate the policy version 2.y to version 1.z, which represents the highest existing minor version z for major version one (1). [0157] In an embodiment the new policy 1405 version 4.w and all the translated policy versions 1415 , 3.x, 2.y and 1.z, are collectively the output policies 1430 that can be deployed to various clients, or management consoles, in the managed environment system 100 . In an embodiment the output policies 1430 are forwarded to a GPO 1420 (group policy object) of the managed environment system 100 . [0158] In an embodiment the new policy 1405 version 4.w is forwarded to the GPO 1420 at the time of deployment, and thereafter each translated version 1415 , 3.x, 2.y and 1.z, is forwarded to the GPO 1420 as the respective translation is established. In an alternate embodiment once all necessary policy schema translations are finalized, all output policy versions 1430 are then forwarded to the GPO 1420 . In this alternate embodiment and the example of FIG. 14 , new policy 1405 version 4.x and translated policy versions 1415 , 3.x, 2.y and 1.z, are forwarded to the GPO 1420 when all the translated versions 1415 are generated. [0159] In an embodiment, from the GPO 1420 each output policy 1430 is forwarded to the client, or management console 150 , to which the policy is to be deployed and which supports the respective major version value. Referring to the example of FIG. 14 , translated policy version 3.x 1445 is forwarded to client A 1435 as client A 1435 supports major version three (3). In this example translated policy version 1.z 1455 is forwarded to client B 1440 as client B 1440 supports major version one (1). [0160] In the example of FIG. 14 client A 1435 and client B 1440 may thereafter have to perform parameter stripping when implementing the new policy, version 3.x 1445 and version 1.z 1455 respectively, or any portion thereof, to delete, or otherwise strip out or ignore, those parameters existing in the policy version that is deployed to them that are not supported by their client version. [0161] For example, assume the schema translation engine 1425 translated policy 1405 version 4.w to version 3.8, which is thereafter forwarded to client A 1435 . Also assume that client A's version is 3.4. In this case the policy version 3.8 deployed to client A 1435 has a larger minor version value (8) than the minor version value (4) of client A 1435 . Parameter stripping may therefore be necessary when client A 1435 implements the policy, to delete or otherwise strip out or ignore, those parameters that exist in policy version 3.8 that are not supported in client A's version 3.4. [0162] FIG. 15 is an example of policy schema translation wherein new IPsec encryption features are incorporated into a set of rules in a new firewall policy 1525 version 4.2 on a management console, or client, 1500 . In this example the new IPsec encryption features caused a major schema revision, i.e., the latest firewall policy 1525 major version value was increased, or incremented, by one, e.g., from three (3) to four (4). As in our example, the most currently released policy version may also reflect minor changes, and thus, its minor version value may not be zero (0). [0163] In the example of FIG. 15 various other clients in the managed environment system 100 support other, lesser, versions than the client 1500 . In this example, client B 1505 supports version 4.1, client C 1510 supports version 3.6, client D 1515 supports version 2.5 and client E 1520 supports version 1.1. [0164] In an embodiment, to deploy the firewall policy 1525 to the various clients B 1505 , C 1510 , D 1515 and E 1520 , the schema translation engine 1425 hosted on management console, or client, A 1500 interprets a translation collection 1535 to translate the firewall policy 1525 version 4.2 to version 3.8, which in this example represents the highest existing minor version (8) for major version three (3). The schema translation engine 1425 interprets the translation collection 1535 to translate the firewall policy version 3.8 to version 2.5, which in this example represents the highest existing minor version (5) for major version two (2). The schema translation engine 1425 interprets the translation collection 1535 to translate the firewall policy version 2.5 to version 1.3, which in this example represents the highest existing minor version (3) for major version one (1). [0165] In this embodiment example the new firewall policy 1525 version 4.2 and all the translated firewall policy versions, 3.8, 2.5 and 1.3, collectively the output policies 1540 , are forwarded to a GPO 1420 of the managed environment system 100 . In an embodiment, from the GPO 1420 each output policy 1540 is forwarded to the client to which the firewall policy is to be deployed and which supports the respective major version value. In the example of FIG. 15 , new firewall policy version 4.2 is forwarded to client B 1505 as client B 1505 supports major version four (4). Translated firewall policy version 3.8 is forwarded to client C 1510 as client C 1510 supports major version three (3). Translated firewall policy version 2.5 is forwarded to client D 1515 and translated firewall policy version 1.3 is forwarded to client E 1520 as client D 1515 supports major version two (2) and client E 1520 supports major version one (1). [0166] In the example of FIG. 15 client B 1505 supports version 4.1, yet it has been forwarded new firewall policy 1525 version 4.2. In this case parameter stripping may be necessary when the firewall policy, or any portion thereof, is implemented, to delete those parameters existing in new firewall policy 1525 version 4.2 that are not supported by client B's version 4.1. Likewise, client C 1510 supports version 3.6, yet it has been forwarded translated policy version 3.8. Parameter stripping may be necessary in this case when the firewall policy, or any portion thereof, is implemented, to delete those parameters existing in translated firewall policy version 3.8 that are not supported by client C's version 3.6. Similarly, client E 1520 supports version 1.1, yet it has been forwarded translated firewall policy version 1.3. Parameter stripping may be required in this situation when the firewall policy, or any portion thereof, is implemented, to delete those parameters existing in translated firewall policy version 1.3 that are not supported by client E's version 1.1. [0167] In the example of FIG. 15 translated policy version 2.5 has been forwarded to client D 1515 and client D 1515 supports version 2.5. In this case no parameter stripping will be necessary as client D 1515 supports the same version as the translated firewall policy it has been forwarded from the GPO 1420 . [0168] In some circumstances the translation collection may not support a translation from one major minor policy version to another. In an embodiment in these situations, parameter stripping is used to generate a minor version of a major policy version that is supported by the translation collection for policy schema translation. [0169] Referring to the example of FIG. 16 , policy schema translation is to be performed for new policy version 4 . 7 1630 hosted on management console, or client, 1600 . The translation collection 1610 supports a translation 1605 from policy version 4.7 to version 3.8. The translation collection 1610 also supports a translation 1615 from policy version 3.6 to version 2.5. In this example the translation collection 1610 fails to support a translation from policy version 3.8 to version 2.5. [0170] Thus, in this embodiment example the schema translation engine 1425 will interpret the translation collection 1610 to translate 1605 policy version 4.7 to policy version 3.8. The client API 1620 of the respective management console 1600 will then parameter strip as necessary to, in effect, generate 1635 a policy version 3.6 from translated version 3.8. Thereafter, the schema translation engine 1425 can interpret the translation collection 1610 to translate 1615 policy version 3.6 to policy version 2.5. The resultant output polices 1640 will consist of policy version 4.7 1630 , policy version 3.8 1645 and policy version 2.5 1650 . [0171] In an embodiment therefore, a combination of policy schema translation and parameter stripping, performed in the order as necessary, can be utilized to create various translated policy versions from one new policy version. [0172] FIG. 17 illustrates an embodiment logic flow for a methodology for policy schema translation in a managed environment system 100 . While the following discussion is made with respect to systems portrayed herein, the operations described may be implemented in other systems. Further, the operations described herein are not limited to the order shown. Additionally, in other alternative embodiments more or fewer operations may be performed. [0173] Referring to FIG. 17 , in an embodiment a new policy version is generated, or otherwise created, and hosted on a management console of a managed environment system 1700 . In an embodiment a translation collection is generated or updated to provide the necessary translation information to translate between two or more versions of the policy 1705 . At decision block 1710 a determination is made as to whether the new policy version is to be deployed. If no, no further action is necessary until the new policy version is to be deployed. [0174] If, however, at decision block 1710 the determination is made that the new policy version is to be deployed, at decision block 1715 a determination is made as to whether the translation collection includes translation information to translate current policy version x.y to policy version x-1.z. Thus, at decision block 1715 a determination is made as to whether the translation collection supports translating a current policy version to a policy version whose major version value is one less than the current policy version major value. If no, parameter stripping is used on the current policy version as necessary to generate a current policy version that can, with the translation collection, be translated to a new, lower major, policy version 1720 . [0175] Whether or not parameter stripping has been employed on the current policy version x.y, the management console hosting the current policy version x.y interprets the translation collection to generate policy version x-1.z 1725 . [0176] At decision block 1730 a determination is made as to whether or not all policy translations have been generated, or otherwise effected. If no, the translated policy version x-1.z becomes the new current policy version x.y 1735 and the logic returns to decision block 1715 to determine if the translation collection supports translating the new current policy version x.y to a policy version whose major version value is one less (x-1) than the current policy major version value x. [0177] If at decision block 1730 a determination is made that all policy translations have been generated, the respective management console forwards the new policy version and all translated policy versions to a GPO of the managed environment system 1740 . The GPO thereafter deploys the current policy version and/or one or more translated policy versions, as needed, to one or more clients in the managed environment system 1745 . The policy schema translation for the current new policy version is then ended 1750 . The embodiment logic of FIGS. 7A and 7B or the embodiment logic of FIG. 11 can thereafter be used for processing object commands of the newly deployed policy version. [0178] In an embodiment the methodology of FIG. 17 can be used by a client API 110 to deploy an appropriate translated policy version to a remote server 115 in order that policy commands issued by a mgmt app 105 will be, if not fully, at least partially, implemented by the remote server 115 . In an embodiment the client API 110 will interpret the translation collection to create translated policy versions until it generates a translated policy version whose major version value is compatible with the remote server 115 . In this embodiment the client API 110 will then deploy, or otherwise forward, the compatible translated policy version to the remote server 115 . [0179] FIG. 18 illustrates an embodiment logic flow for a methodology for policy deployment, box 1745 of FIG. 17 , in a managed environment system 100 . While the following discussion is made with respect to systems portrayed herein, the operations described may be implemented in other systems. Further, the operations described herein are not limited to the order shown. Additionally, in other alternative embodiments more or fewer operations may be performed. [0180] For an embodiment policy deployment to one or more clients in a managed environment system, a first policy version x is identified 1800 . A first client y in the managed environment system is also identified 1805 . At decision block 1810 a determination is made as to whether client y's version is compatible with policy version x; in other words, does policy version x's major version value equal client y's major version value? If yes, policy version x is deployed, or otherwise sent or made available, to client y 1815 and client y 1815 accepts deployed policy version x. [0181] Whether or not client y's version is compatible with policy version x, at decision block 1820 a determination is made as to whether or not there are any more clients in the managed environment system. If yes, y is incremented to a new client 1825 and the logic returns to decision block 1810 where a determination is made as to whether new client y's version is compatible with policy version x. [0182] If at decision block 1820 it is determined that there are no more clients in the managed environment system then at decision block 1830 a determination is made as to whether there is another policy version to be deployed. If yes, x is incremented to a new policy version to be deployed 1835 , a first client y is identified 1805 , and the logic returns to decision block 1810 to determine whether client y's version is compatible with policy version x. [0183] Once all the policy versions to be deployed have been deployed to one or more clients in the managed environment system the current policy deployment is ended 1840 . Such policy versioning is efficient in that one policy version is used to generate one or more translated policy versions that are deployed to various clients in a managed environment system. Such policy versioning is secure as the policy versions that are deployed and subsequently enforced by various clients are as secure as the version supported by each respective client. Version Targeting [0184] In an embodiment the default is to deploy a policy to all clients in a managed environment system 100 using schema policy translation and parameter stripping as necessary. There are scenarios, however, where a system administrator may wish to deploy a policy to only one or more specific client, or platform, versions, i.e., effect version targeting. Such scenarios include, but are not limited to, a desire to protect against a platform-specific vulnerability and a desire to enable network access for an application on one or more specific platforms. [0185] In an embodiment each client in a managed environment system has an associated version and each client platform in the managed environment system has an associated version. In an embodiment the management user interface of a client, or management console 150 , exposes specific platforms hosted in the managed environment system 100 and their associated policy versions at policy deployment time. [0186] In an embodiment version targeting uses both schema policy translation and parameter stripping, as needed, on a respective management console 150 supporting a new policy version to be deployed prior to policy deployment to ensure that the policy is configured, or otherwise translated, for the specific version(s) of the target client(s) and/or platform(s). In an embodiment a targeting parameter is used when deploying the new and translated policy versions to ensure that no policy version is accepted or, alternately, used by clients or platforms of non-targeted versions that may support a deployed policy version. [0187] FIG. 19 is an example of a policy deployment action, or command, 1900 that includes a targeting parameter 1905 . In the example of FIG. 19 only platform versions 6001 and 5200 are to accept, or, alternately, use any deployed policy version. [0188] In an embodiment, if a deployed policy version is compatible with a particular client or platform version but the client or platform version is not included in the targeting parameter 1905 then neither the non-targeted client nor the non-targeted platform will accept the policy version when it is deployed. In this embodiment for example, assume a policy version 5.3 is deployed and assume a platform version 5300 is compatible with policy version 5.3. Policy deployment action 1900 , however, does not include platform version 5300 in the targeting parameter 1905 . Thus, in this embodiment example platforms with version 5300 will not accept the policy version 5.3 when it is deployed. [0189] In an alternate embodiment, if a deployed policy version is compatible with a particular client or platform version but the client or platform version is not included in the targeting parameter 1905 then the non-targeted client, or non-targeted platform, will accept and store the deployed policy version but will not thereafter implement, or otherwise enforce, the policy version. In this alternate embodiment, for example, assume a policy version 5.3 is deployed and assume a platform version 5300 is compatible with policy version 5.3. Policy deployment action 1900 , as noted, does not include platform version 5300 in the targeting parameter 1905 . In this alternate embodiment example policy version 5.3 will be deployed to and accepted and stored by platforms with version 5300 . In this alternate embodiment example, however, policy version 5.3 will not thereafter be implemented, or otherwise enforced, by platforms with version 5300 . [0190] In another alternate embodiment, if a deployed policy version is compatible with a particular client or platform version but the client or platform version is not included in the targeting parameter 1905 then the compatible policy version will not be deployed to the client or platform version. In this other alternate embodiment for example, assume a policy version 5.3 is to be deployed and assume platform version 5300 is compatible with policy version 5.3. As noted however, policy deployment action 1900 does not include platform version 5300 in the targeting parameter 1905 . Thus, in this other alternate embodiment example policy version 5.3 will not be deployed, or otherwise provided to, platform version 5300 . [0191] FIG. 20 illustrates an embodiment logic flow for a methodology for version targeting during policy deployment in a managed environment system 100 . While the following discussion is made with respect to systems portrayed herein, the operations described may be implemented in other systems. Further, the operations described herein are not limited to the order shown. Additionally, in other alternative embodiments more or fewer operations may be performed. [0192] For an embodiment policy deployment to one or more clients in a managed environment system, a first policy version x is identified 1800 . A first client y in the managed environment system is also identified 1805 . At decision block 1810 a determination is made as to whether client y's version is compatible with policy version x. If yes, at decision block 2000 a determination is made as to whether the client y version is a targeting parameter in the policy deployment action, or command. If yes, policy version x is deployed, or otherwise sent or made available, to client y 1815 and client y accepts the deployed policy version x. [0193] If, however, at decision block 2000 the determination is made that client y's version is not a targeting parameter in the policy deployment action, the current policy x is not deployed to client y, or client y does not accept deployed policy version x, or client y accepts the deployed policy version x but will not thereafter implement it. [0194] At decision block 1820 a determination is made as to whether or not there are any more clients in the managed environment system. If yes, y is incremented to a new client 1825 and the logic returns to decision block 1810 where a determination is made as to whether new client y's version is compatible with policy version x. [0195] If at decision block 1820 it is determined that there are no more clients in the managed environment system then at decision block 1830 a determination is made as to whether there is another policy version to be deployed. If yes, x is incremented to a new policy version to be deployed 1835 , a first client y is identified 1805 , and the logic returns to decision block 1810 to determine whether client y's version is compatible with policy version x. [0196] Once all the policy versions to be deployed have been deployed to one or more clients in the managed environment system the current policy deployment with version targeting is ended 1840 . Computing Device System Configuration [0197] FIG. 21 is a block diagram that illustrates an exemplary computing device system 2100 upon which an embodiment can be implemented. The computing device system 2100 includes a bus 2105 or other mechanism for communicating information, and a processing unit 2110 coupled with the bus 2105 for processing information. The computing device system 2100 also includes system memory 2115 , which may be volatile or dynamic, such as random access memory (RAM), non-volatile or static, such as read-only memory (ROM) or flash memory, or some combination of the two. The system memory 2115 is coupled to the bus 2105 for storing information and instructions to be executed by the processing unit 2110 , and may also be used for storing temporary variables or other intermediate information during the execution of instructions by the processing unit 2110 . The system memory 2115 often contains an operating system and one or more programs, and may also include program data. [0198] In an embodiment, a storage device 2120 , such as a magnetic or optical disk, is also coupled to the bus 2105 for storing information, including program code comprising instructions and/or data. [0199] The computing device system 2100 generally includes one or more display devices 2135 , such as, but not limited to, a display screen, e.g., a cathode ray tube (CRT) or liquid crystal display (LCD), a printer, and one or more speakers, for providing information to a computing device user. The computing device system 2100 also generally includes one or more input devices 2130 , such as, but not limited to, a keyboard, mouse, trackball, pen, voice input device(s), and touch input devices, which a computing device user can use to communicate information and command selections to the processing unit 2110 . All of these devices are known in the art and need not be discussed at length here. [0200] The processing unit 2110 executes one or more sequences of one or more program instructions contained in the system memory 2115 . These instructions may be read into the system memory 2115 from another computing device-readable medium, including, but not limited to, the storage device 2120 . In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software program instructions. Thus, the computing device system environment is not limited to any specific combination of hardware circuitry and software. [0201] The term “computing device-readable medium” as used herein refers to any medium that can participate in providing program instructions to the processing unit 2110 for execution. Such a medium may take many forms, including but not limited to, storage media and transmission media. Examples of storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory, CD-ROM, digital versatile disks (DVD), magnetic cassettes, magnetic tape, magnetic disk storage, or any other magnetic medium, floppy disks, flexible disks, punch cards, paper tape, or any other physical medium with patterns of holes, memory chip, or cartridge. The system memory 2115 and storage device 2120 of the computing device system 2100 are further examples of storage media. Examples of transmission media include, but are not limited to, wired media such as coaxial cable(s) and copper wire, and wireless media such as fiber optic signals, acoustic signals, RF signals and infrared signals. [0202] The computing device system 2100 also includes one or more communication connections 2150 coupled to the bus 2105 . The communication connection(s) 2150 provide a two-way data communication coupling from the computing device system 2100 to other computing devices on a local area network (LAN) 2165 and/or wide area network (WAN), including the World Wide Web, or Internet 2170 . Examples of the communication connection(s) 2150 include, but are not limited to, an integrated services digital network (ISDN) card, modem, LAN card, and any device capable of sending and receiving electrical, electromagnetic, optical, acoustic, RF or infrared signals. [0203] Communications received by the computing device system 2100 can include program instructions and program data. The program instructions received by the computing device system 2100 may be executed by the processing unit 2110 as they are received, and/or stored in the storage device 2120 or other non-volatile storage for later execution. Conclusion [0204] While various embodiments are described herein, these embodiments have been presented by way of example only and are not intended to limit the scope of the claimed subject matter. Many variations are possible which remain within the scope of the following claims. Such variations are clear after inspection of the specification, drawings and claims herein. Accordingly, the breadth and scope of the claimed subject matter is not to be restricted except as defined with the following claims and their equivalents.

Versioning management provides for efficient and effective handling of varying policy versions, client versions and client platform versions in one system. Software version negotiation provides for simplified, secure policy management in an environment supporting varying versions of the same software product. In conjunction with parameter stripping, which resolves differences among varying minor versions of a software policy, software version negotiation allows for management tools of one version to manage client software, clients and/or client platforms of another version. Policy schema translation, in conjunction with parameter stripping as needed, provides a mechanism for converting policies that normally would be impossible to interpret on varying clients and/or client platforms to policy versions that can be understood by these clients and/or client platforms. Version targeting allows an administrator to push a policy to specific clients and/or client platforms to, among other things, address identified security issues or to provide version specific application enablement or enhancement. Together, these various versioning management methodologies simplify administration of a system consisting of varying policy versions, client versions and/or client platform versions while enhancing the flexibility of the system to apply policy throughout the system or any portion thereof.

TECHNICAL FIELD [0001] The invention relates to a broadcast communication system architecture and receiving terminals used within the system, and more particularly to a digital television (TV) network architecture and client terminals. BACKGROUND [0002] The conventional terrestrial digital TV transmission systems widely employ a single-frequency network architecture, namely, TV towers at different locations transmit the same signal at the same frequency simultaneously. [0003] The disadvantage is that the number of the transmit towers and the transmit power are subject to certain constraints. For urban topography, there will be many shadow areas for indoor reception, and for rural topography, the coverage range will be limited in some extent. On the other hand, the conventional digital TV transmission system is for one-way broadcast. This one-way broadcast mode transmits a fixed number of video programs with limited bandwidth, without taking into account the specific service needs of users, e.g., two-way services such as video on-demand, information customization, games, etc. SUMMARY [0004] The invention intends to provide a digital TV network architecture and client terminal, to solve the inadequacy of the only existing broadcast approach, the incapability in integrating and sharing with other networks, and the improper allocation of broadcast and network resources. [0005] According to the aforementioned purpose, a client terminal according to this invention is implemented, wherein the client terminal comprises: a first receiving module for connecting with a broadband communication network, and a second receiving module for connecting with a digital TV broadcast system, wherein the client terminal is operable to receive, via the second receiving module, an information index transmitted by the digital TV broadcast system, and to retrieve corresponding information content from the broadband communication network via the first receiving module based on the information index. [0006] According to the above main features, the client terminal receives, via the second receiving module, the content transmitted by the digital TV broadcast system, and selectively stores and recommends the content according to a user's behavior habits. [0007] According to the above main features, the client terminal is operable to directly retrieve information content from the broadband communication network via the first receiving module. [0008] According to the above main features, the broadband communication network deploys an edge server that is close to the client terminal, wherein the client terminal connects to the broadband communication network via the edge server. [0009] According to the above main features, the digital TV broadcast system coordinates with the broadband communication network by connecting to a content clustering server, wherein the content clustering server chooses popular content from a plurality of data sources and generates an information index, wherein the information index of the popular content is sent to the client terminal via the digital TV broadcast system and the second receiving module, such that the client terminal is operable to retrieve the corresponding popular content from the edge server via the first receiving module based on the information index of the popular content. [0010] According to the above main features, the client terminal is connected to the digital TV broadcast system through a wireless digital broadcast channel. [0011] According to the above main features, the client terminal selectively downloads some of the popular content from the edge server to the client terminal according to a user's behavior habits, and recommends the content to the user. [0012] According to the aforementioned purpose, a digital TV broadcast system coordinated with a broadband communication network according to this invention is implemented, for providing information to a client terminal, wherein the broadband communication network comprises an edge server that is close to the client terminal, wherein a bidirectional information channel is provided between the client terminal and the edge server, a broadcast information channel is provided between the digital TV broadcast system and the edge server, and a broadcast information channel is provided between the digital TV broadcast system and the client terminal. [0013] According to the above main features, the digital TV broadcast system coordinates with the broadband communication network by connecting to a content clustering server, wherein the content clustering server performs clustering analysis on multimedia content from a plurality of data sources based on the sources of the content, analysis and prediction of relevance between the content and users, and feedback information to the content including user's click response, to identify the multimedia content as popular content or normal content, so as to choose, classify and index the popular content. [0014] According to the above main features, the content clustering server sends the popular content to the edge server through the information channel between the digital TV broadcast system and the edge server. [0015] According to the above main features, the digital TV broadcast system sends the popular content or its index directly to the client terminal through the information channel between the digital TV broadcast system and the client terminal. [0016] According to the above main features, the digital TV broadcast system sends the popular content or its index to the client terminal through the information channel between the digital TV broadcast system and the client terminal, wherein the client terminal retrieves the corresponding popular content from the edge server via the information channel between the client terminal and the edge server based on the index of the popular content. [0017] According to the above main features, the content clustering server sends all the content to the broadband communication network, and the client terminal is connected to the broadband communication network via the information channel between the client terminal and the edge server. [0018] According to the above main features, the information channel between the digital TV broadcast system and the edge server comprises a cable digital broadcast channel, a satellite digital broadcast channel, or a terrestrial digital broadcast channel. [0019] According to the above main features, the information channel between the digital TV broadcast system and the client terminal comprises a wireless digital broadcast channel. [0020] According to the above main features, the information channel between the digital TV broadcast system and the edge server and the information channel between the digital TV broadcast system and the client terminal are two logical channels on one physical channel. [0021] According to the above main features, the information channel between the digital TV broadcast system and the edge server and the information channel between the digital TV broadcast system and the client terminal are two different physical channels. [0022] According to the aforementioned purpose, an information transmission network according to the invention is implemented, for providing information to a client terminal, wherein the information transmission network comprises a broadband communication network and a digital TV broadcast system, wherein the broadband communication network comprises an edge server that is close to the client terminal, wherein a bidirectional information channel is provided between the client terminal and the edge server, a broadcast information channel is provided between the digital TV broadcast system and the edge server, and a broadcast information channel is provided between the digital TV broadcast system and the client terminal. [0023] According to the above main features, the information transmission network further comprises a content clustering server connected to the broadband communication network and the digital TV broadcast system, wherein the content clustering server performs clustering analysis on multimedia content from a plurality of data sources based on the sources of the content, analysis and prediction of relevance between the content and users, and feedback information to the content including user's click response, to identify the multimedia content as popular content or normal content, so as to choose, classify and index the popular content. [0024] According to the above main features, the content clustering server sends the popular content to the edge server through the information channel between the digital TV broadcast system and the edge server. [0025] According to the above main features, the digital TV broadcast system sends the popular content or its index directly to the client terminal through the information channel between the digital TV broadcast system and the client terminal. [0026] According to the above main features, the digital TV broadcast system sends the popular content or its index to the client terminal through the information channel between the digital TV broadcast system and the client terminal, wherein the client terminal retrieves the corresponding popular content from the edge server via the information channel between the client terminal and the edge server based on the index of the popular content. [0027] According to the above main features, the content clustering server sends all the content to the broadband communication network, and the client terminal is connected to the broadband communication network via the information channel between the client terminal and the edge server. [0028] According to the above main features, the information channel between the digital TV broadcast system and the edge server comprises a cable digital broadcast channel, a satellite digital broadcast channel, or a terrestrial digital broadcast channel. [0029] According to the above main features, the information channel between the digital TV broadcast system and the client terminal comprises a wireless digital broadcast channel. [0030] According to the above main features, the information channel between the digital TV broadcast system and the edge server and the information channel between the digital TV broadcast system and the client terminal are two logical channels on one physical channel. [0031] According to the above main features, the information channel between the digital TV broadcast system and the edge server and the information channel between the digital TV broadcast system and the client terminal are two different physical channels. [0032] According to the aforementioned purpose, a digital TV heterogeneous network architecture of the invention is implemented for providing digital TV content to a client terminal, wherein the digital TV heterogeneous network architecture comprises: a transmission control module, a broadcast TV network and a secondary network, wherein both the broadcast TV network and the secondary network are connected to the transmission control module, wherein the broadcast TV network is a unidirectional transmission network for sending the digital TV content to the client terminal directly, and the secondary network is a bidirectional network for transmitting the digital TV content to the client terminal and for transmitting control information between the client terminal and the transmission control module, wherein the transmission control module governs the digital TV content to be transmitted via the broadcast TV network and the secondary network. [0033] According to the above main features, the broadcast TV network further comprises a multiplexing and distribution module connected to the transmission control module, for performing channel multiplexing and content distribution for the content output from the transmission control module; wherein the channel multiplexing means that a plurality pieces of content might occupy one frequency resource chronologically or a plurality pieces of content might occupy one time block at different frequency resources. [0034] According to the above main features, the control information comprises a VOD request, a broadcast content retransmission request, or a direct video content request. [0035] According to the above main features, the digital TV content comprises broadcast content as well as VOD content for the client terminal. [0036] According to the above main features, the secondary network comprises a 3G, LTE, or WiFi network and the wired Internet, wherein the 3G, LTE, or WiFi network is used to connect the client terminal with the Internet, wherein the client terminal uploads control information or video content to the Internet via the 3G, LTE, or WiFi network. The Internet delivers feedback information, broadcast retransmission content or direct video content from the transmission control module to the client terminal via the 3G, LTE, or WiFi network; wherein the feedback information comprises acceptance, waiting, or timeout of a VOD request, acceptance, waiting, or timeout of a broadcast content retransmission request, or acceptance, waiting, or timeout of a direct content request. [0037] According to the above main features, the client terminal further comprises a storage device, for storing the digital TV content transmitted to the client terminal from the broadcast TV network or the secondary network. [0038] According to the above main features, the broadcast TV network architecture further comprises a content classification and preparation module connected to the transmission control module, for classifying acquired digital TV content and further creating an index label for each piece of multimedia content. [0039] According to the above main features, the broadcast TV network architecture further comprises a content acquisition module connected to the content classification and preparation module, for acquiring digital TV content from various sources. [0040] According to the above main features, the secondary network has a plurality of information transmission channels, and the client terminal comprises an evaluation unit for evaluating a channel condition in real-time based on return channels of the information transmission channels, so as to select an optimal information transmission channel. [0041] According to the aforementioned purpose, a terrestrial digital TV network architecture according to this invention is implemented, wherein the terrestrial digital TV network architecture comprises: a TV tower base station and a client terminal; wherein a downlink at a first frequency and an uplink at a second frequency are employed between the TV tower base station and the client terminal. [0042] According to the above main features, the downlink carries broadcast information transmitted to all users in a broadcast mode and proprietary information specific to individual users transmitted in a broadcast or directional transmission mode; and the uplink is accessed according to a time-frequency resource table specified individually and delivered on the downlink. [0043] According to the above main features, an uplink signal is transmitted by the client terminal in a directional transmission mode; wherein the directional transmission mode is implemented by a directional antenna or through beamforming of an antenna array. [0044] According to the above main features, a wireless repeater is also included, wherein the TV tower base station transmits a broadcast signal to the wireless repeater, which forwards the broadcast signal to the client terminal; wherein the client terminal transmits an uplink signal to the wireless repeater, which forwards the uplink signal to the TV tower base station. [0045] According to the above main features, the wireless repeater comprises a pair of back-to-back wireless access points, one for receiving and the other for transmitting; the wireless repeater utilizes analog intra-frequency forwarding, analog inter-frequency forwarding, digital intra-frequency forwarding, or digital inter-frequency forwarding, or utilizes Bluetooth or Wifi forwarding. [0046] According to the aforementioned purpose, a TV tower base station of this invention is implemented for transceiving signals with a client terminal, wherein: the TV tower base station comprises a receiving device and a transmitting device, wherein the transmitting device transmits information to the client terminal at a first frequency, and the receiving device receives information transmitted from the client terminal at a second frequency. [0047] According to the above main features, the information transmitted by the transmitting device comprises broadcast information transmitted to all users in a broadcast mode, and proprietary information specific to individual users transmitted in a broadcast or directional transmission mode. [0048] According to the above main features, the receiving device receives the information transmitted from the client terminal according to a time-frequency resource table for the client terminal. [0049] According to the aforementioned purpose, a client terminal of this invention is implemented for transceiving signals with a TV tower base station, wherein: the client terminal comprises a receiving device and a transmitting device, wherein the receiving device receives information transmitted from the TV tower base station at a first frequency, and the transmitting device transmits information to the TV tower base station at a second frequency. [0050] According to the above main features, the client terminal transmits information to the TV tower base station in a directional transmission mode, wherein the directional transmission mode is implemented by a directional antenna or through beamforming of an antenna array. [0051] With the technical solutions of the invention, the integration of the broadcast network and other networks is provided, to support multiple network access modes for users, and to provide accurate, efficient, and high quality information services to users with best efforts. Moreover, such heterogeneous architectures utilize the WiFi/GPRS/3G, LTE and broadcast networks in a site-specific way to provide a collaborative coverage to solve the blind spots and shadows in the cities. In addition, the network architecture of the invention can support an uplink of broadcasting and also utilizes the different advantages of various networks in coverage range, transmission speed, mobility support, QoS support, setup cost, and targeting market, which are complementary to each other, thereby providing services with more variety, higher quality, and lower price for users. BRIEF DESCRIPTION OF THE DRAWINGS [0052] In this invention, like reference numerals refer to like parts throughout the drawings, in which: [0053] FIG. 1 is a schematic diagram of an information transmission network combining a digital TV broadcast system and a broadband communication network according to a first embodiment of the invention; [0054] FIG. 2 is a schematic block diagram of a Broadcast-to-Client channel and a Broadcast-to-Server channel in FIG. 1 ; [0055] FIG. 3 is a schematic diagram of a digital TV heterogeneous network architecture according to a second embodiment; [0056] FIG. 4 is a schematic diagram of a network architecture according to a third embodiment of the invention; [0057] FIG. 5 is a schematic diagram of a network architecture according to a fourth embodiment of the invention. DETAILED DESCRIPTION [0058] The technical solutions of this invention will be further described below in connection with the figures and embodiments. [0059] As seen from the prediction in the Background, the explosive increase in demands for video data services places a heavy burden on the broadband communication network; while the high homogenity of a large amounts of data services makes it possible for the digital TV broadcast system to assist the broadband communication network. Accordingly, the digital TV broadcast system and the broadband communication network of multimedia data are inevitably integrated and complement each other. Thus, this invention proposes a network architecture coordinated with the broadband communication network, and is particularly applicable in the digital TV broadcast system. [0060] As shown in FIG. 1 , with a network architecture that coordinates the broadband communication network and the digital TV broadcast system, the information transmission network of this invention is operable for providing information to a client terminal, and mainly includes two sub-networks, the broadband communication network and the digital TV broadcast system. The broadband communication network includes a plurality of servers in the network. Particularly in this invention, a server close to the client terminal is referred as an edge server, wherein a bidirectional information channel is provided between the client terminal and the edge server, an information channel is provided between the digital TV broadcast system and the edge server, and an information channel is provided between the digital TV broadcast system and the client terminal. [0061] The edge server is deployed at the backend of the digital TV broadcast system and the broadband communication network. The digital TV broadcast system is connected to the client terminal, forming a Broadcast-to-Client (BC) channel, the digital TV broadcast system is connected to the edge server, forming a Broadcast-to-Server (BS) channel, and the client terminal is connected to the edge server, forming a Server-to-Client (SC) channel. [0062] Among the above three channels, the SC channel is a bidirectional channel, for interconnectivity between the client and the broadband communication network. The BC channel and the BS channel may be two logical channels on one physical channel, wherein the BC channel and the BS channel multiplexes the physical channel by time-division multiplexing or frequency-division multiplexing. In another aspect, the BC channel and the BS channel may simply be two different physical channels. Regardless the form of the BC channel and the BS channel, the BC channel and the BS channel are not limited to unidirectional channels. In other words, both the BC channel and the BS channel may include an uplink, wherein the uplink and downlink of the BC channel and the BS channel are differentiated by different frequency bands. [0063] In consideration of the unidirectional or bidirectional characteristics of the BC channel, the BS channel and the SC channel, the BS channel may be a cable digital broadcast channel, or a satellite digital broadcast channel, or a terrestrial digital broadcast channel, the BC channel may be a wireless digital broadcast channel, and the SC channel may be a common wired network channel, or a Wifi channel, etc. [0064] The multimedia data firstly undergoes content clustering. Accordingly, the information transmission network of this invention further comprises a content clustering server, which is connected to the broadband communication network and the digital TV broadcast system, and which is deployed at frontend of the digital TV broadcast system and the broadband communication network. [0065] The content clustering server first analyzes popularity of various multimedia data based on the sources of the multimedia content, analysis and prediction of relevance between the content and users, and feedback information to the content including user's click response, and chooses the content that most people concern (i.e., popular content), such that the popular content is separated from normal content. Next, the popular content is further processed to extract key words of the multimedia data based on the popularity characteristics of the multimedia data, which may then be indexed by the key words, and all the indices are managed collectively on the content clustering server. [0066] For each multimedia data label, the content clustering server needs to continuously update its popularity, so as to update the key words and the corresponding index. Accordingly, the popularity and index of multimedia data are dynamic parameters. For example, in a period of time, some multimedia content is concerned by many people, and the multimedia content becomes popular. After a time period, the concern for the multimedia content decreases, and then the content clustering server may modify the label of the multimedia content from popular to normal. Finally, the digital TV broadcast system assists the broadband communication network to deliver the popular content. [0067] During the data delivery, the content clustering server groups the multimedia data into two clusters: one cluster for the popular content in all the multimedia data and its information index, the other cluster for content of all the multimedia data. The content clustering server delivers the two clusters through two different networks. [0068] The first network is the digital TV broadcast system, for delivering the popular content and/or the information index of the content. The transmission on the digital TV broadcast system is carried through a BS channel and a BC channel. The BS channel transmits the popular content directly to the edge server close to the terminal, and the BC channel transmits the popular content and/or the information index of the content directly to the client terminal. Alternatively, the client terminal may retrieve the full information of the corresponding popular content from the edge server via the SC channel based on the information index of the popular content. [0069] The secondary network is the broadband communication network, for delivering all the multimedia data and the information index thereof. The content clustering server delivers all the content and the information index thereof to the broadband communication network. The edge server is capable of both receiving the BS channel and accessing the broadband communication network. The client terminal connects to the broadband communication network via the SC channel, so as to retrieve the information index of all the multimedia data and the full content. [0070] As a preferred embodiment of this invention, FIG. 2 illustrates the content clustering, BS channel and BC channel which constitute three essential parts of this invention. The BS channel may be a cable digital broadcast channel, a satellite digital broadcast channel, or a terrestrial digital broadcast channel, which is of high spectrum efficiency. A large amount of popular multimedia data can be delivered to the edge server directly via the BS channel. The BC channel merely employs wireless digital broadcasting, can be widely deployed, can accommodate different requirements of terminals, and benefits power saving in some extent. [0071] Broadcasting is characterized in the point-to-plane information transmission. The delivery of the popular content through the digital TV broadcast system may offload a high traffic from the broadband communication network. The client terminal receives the broadcast popular content and its information index via the BC channel, may selectively store some popular content for recommendation according to user's behavior habits, and may also store the index information of the popular content. The user may select information based on the recommendation from the client terminal, the index information or other requirements. Although the user does not concern the source of the information, the three different access modes can ensure the user to obtain the required information more quickly and accurately. Based on the user's needs, the user may decide whether to browse the recommended content, whether to browse all the content of the index information, or whether to inquire about other information. If the user simply browses the content recommended by the terminal, the information may be found on the client terminal itself; if the user is interested in specific content of the index information, such information may be retrieved from the nearest edge server via the SC channel; or if the user want to query other content information, the Internet may be accessed via the edge server for information query and browsing. [0072] The integration of the digital TV broadcast system with the broadband communication network is a trend in the next generation of network architecture. Such an architecture may leverage the characteristic of point-to-plane transmission of the digital TV broadcast system, separate and index the popular content by the content clustering server, and deliver the content that most people concern directly via the BC channel, thereby significantly reducing the traffic load on the broadband communication network. By analyzing the user's behaviors, the terminal may store and recommend the content that the user may concern. Meanwhile, the content may be delivered to the edge server via the BS channel, so as to reduce the access distance between the user and most content. Such a digital TV broadcast architecture provides multiple access modes for users, and is capable of providing accurate, efficient and high quality information services for users with best efforts. The digital TV broadcast system combined with the broadband communication network becomes the information highway in the new era, whereby a large amount of multimedia data may be delivered to the user quickly and accurately by broadcasting. [0073] As the continuous development of digital TVs and the trends of diversity and interaction of networks, the integration and heterogeneity based on the coexistence of multiple network become a considerable trend of the future digital TV wireless signal communication development. The various networks have different advantages in coverage range, transmission speed, mobility support, QoS support, setup cost, and targeting market, and are complementary to each other. The network integration intends to utilize the complementary characteristics of the heterogeneous networks, so as to provide services with more variety, higher quality, and lower prices for users. [0074] A terrestrial broadcast TV network architecture established with the concept of heterogeneous networks and having a return link and a collaborative coverage function is shown in FIG. 3 , and mainly comprises a content acquisition module, a content classification and preparation module, a transmission control module, a broadcast TV network, a secondary network, a client terminal and a storage device. The digital TV content of this invention comprises broadcast content as well as VOD content for the client terminal. In particular, as an alternative embodiment of this invention, the broadcast TV network is a broadcast network, the secondary network is a 3G, LTE or WiFi network. Alternatively, the secondary network may be an analog intra-frequency (on-channel) forwarding, digital intra-frequency (differential-channel) forwarding, or digital inter-frequency forwarding communication system, and this invention is not so limited. The connections and functions of these modules are illustrated individually below. [0075] The content acquisition module is connected to the content classification and preparation module, and acquires resource information mainly by means of photography, audio recording, computer synthesis and so on, creates multimedia content from the resource information by post-processing such as editing, composing, clipping, rendering, etc., and sends the created media content a content classification and preparation module. [0076] The content classification and preparation module has a receiving terminal connected to the content acquisition module, and a sending terminal connected to the transmission control module. The content classification and preparation module is primarily used to classify the resulting multimedia content, e.g., according to the characteristics of video source effects: distinguishing between real-time and non real-time services, distinguishing the definition (Ultra HD, HD, SD), distinguishing between the dimensions (3D, 2D); according to the categories of the video source content: distinguishing among sport, financial, political, social, educational, historical, variety, drama, film and TV, and so on. Based on the above, further subdivision may be performed. Finally, an index label is created for each video source, which is packaged separately in accordance with the stream format. [0077] The transmission control module controls both the broadcast TV network and the secondary network to transmit content signals to the client terminal. In this invention, multiple broadcast TV networks and secondary networks may coexist, for example, multiple broadcast networks and multiple 3G or LTE networks, etc. may coexist, at least one or more or all of which has information transmissions being controlled by the transmission control module. The transmission control module communicates control signals and content signals with the client terminal via at least one or more or all of the secondary networks. However, for the broadcast TV network, such as the broadcast network, the transmission control module transmits only content signals. In this invention, the control information comprises a VOD request, a broadcast content retransmission request, or a direct video content request. [0078] As a preferred embodiment of this invention, the broadcast TV network (the broadcast network) also includes a multiplexing and distribution module. The transmission control module provides broadcast multimedia content to the multiplexing and distribution module of the broadcast system. The broadcast multimedia content is service content being broadcast, including normal broadcast services on various channels and user's video on demand (VOD) service content on special channels. The multiplexing and distribution module performs channel multiplexing and matching, etc., for the broadcast content provided by the transmission control module (including normal video services, Ultra HD, 3D, special VOD services, etc.), which is then distributed to clients such as stationary TVs, mobile phones, mobile terminals by radio frequency signal broadcasting. The channel multiplexing herein means that a plurality pieces of content might occupy one frequency resource chronologically or a plurality pieces of content might occupy one time block on different frequency resources. [0079] The secondary network of this invention has a plurality of information transmission channels, typically via a 3G, LTE or WiFi network, connected to the transmission control module. Alternatively, the secondary network may be divided into a frontend and a backend, wherein the frontend is the Internet, and the backend includes a 3G, LTE or WiFi network. The transmission control module has access to the frontend, i.e., the Internet, and the client terminal has access to the backend, i.e., access to a 3G, LTE or WiFi network, etc. The frontend Internet is connected to the backend 3G, LTE or WiFi network, to communicating multimedia services and control signals therebetween. [0080] In this invention, the feedback information comprises acceptance, waiting, or timeout of a VOD request, acceptance, waiting, or timeout of a broadcast content retransmission request, or acceptance, waiting, or timeout of a direct content request. The client terminal may upload control information or video content to the Internet via the 3G, LTE, or WiFi network. The Internet may deliver feedback information, broadcast retransmission content or direct video content from the transmission control module to the client terminal via the 3G, LTE, or WiFi network. [0081] The transmission control module provides multimedia content to the Internet module, and also exchanges control signaling with the Internet. The transmission control module receives control signaling sent from the Internet, including an on-demand (VOD) request, to control the on-demand content output from the transmission control module to the multiplexing and distribution module. After receiving a request from the Internet, the transmission control module will feedback its processing result to the Internet by control signaling, “acceptance” or “waiting”. If a predetermined latency expires, “no response” is returned, and then the user may resend the request. [0082] This invention selects the 3G, LTE or WiFi network because 3G, LTE/WiFi base stations are densely deployed in urban regions, thus almost having a seamless coverage. In one aspect, these modules receive control signals from clients (stationary TVs, mobile terminals, etc) via radio frequency, including on-demand requests, direct content requests, and retransmission requests due to a broadcast content package loss, etc, and also (optionally) receive content uploaded from clients, and further upload the content to the Internet. In another aspect, these modules also receive feedback control signaling from the Internet, including a result feedback for the on-demand request (acceptance, waiting, or no response), a feedback for the direct content request (acceptance, waiting, or no response), and a feedback for a lost package retransmission request (acceptance, waiting, or no response), receive the content requested by the client provided from the Internet, and transmit the information received from the Internet module to the requesting client terminal via a radio frequency. [0083] The client terminal has access to the 3G, LTE or WiFi network, and is equipped with a built-in storage device or connected to an external storage device, for storing information received from the broadcast network or the Internet. In another aspect, the client terminal includes an internal evaluation unit for evaluating a channel condition in real-time based on return channels of the information transmission channels of the secondary network, so as to select an optimal information transmission channel. [0084] As another aspect of this invention, the above terrestrial broadcast TV network architecture has two primary control modes. [0085] One control mode is that the secondary network assists the broadcast TV network to achieve collaborative coverage. In particular, the client terminal assesses the broadcast information received from the broadcast network in real-time to identify missing signals in the broadcast information, and sends a retransmission signal to the transmission control module via the 3G, LTE or WiFi network and then the Internet, whereby the transmission control module transmits the missing signals to the client terminal through the Internet and then the 3G, LTE or WiFi network. [0086] Another control mode is that the secondary network controls the broadcast TV network or the secondary network itself. In particular, the client terminal sends an on-demand control signal to the transmission control module through the 3G, LTE or WiFi network and then the Internet, and the transmission control module transmits the on-demand content to the client terminal through the broadcast network, or again through the Internet and then the 3G, LTE or WiFi network. [0087] The two control modes of this invention are illustrated below by embodiments. [0088] In one aspect, the user receives and watches multimedia content through the broadcast network. When a packet loss occurs in the multimedia content received through the broadcast network due to channel environment deterioration, a retransmission request for the lost content (simply referred to lost packet retransmission request) might be sent to the transmission control module through the 3G, LTE or Wifi wireless network and then the Internet. Upon receiving the request, the transmission control module provides a retransmission of the lost content to the client terminal according to normal criteria (for example, the user request arriving first will be processed first), or prioritization criteria (for example, premium users and privileged users are prioritized). If the user request has to wait, the control signaling feedback to the user is waiting, if the user request can be processed directly, then the control signaling of acceptance is returned, or if the user has been waiting for more than a preset value, then the control signaling of “no response” is returned. This service achieves collaborative coverage of heterogeneous networks and the broadcast network, to overcome the deficiency of packet loss in coverage shadow of the broadcast network. [0089] In another aspect, the user may send a video on-demand (VOD) request to the transmission control module through the 3G, LTE or Wifi wireless network and then the Internet, wherein after receiving the request, the transmission control module controls the on-demand content to be transmitted on the broadcast link, and transmits the on-demand content to the user through the broadcast network timely, so as to meet the on-demand needs of the client terminal. This functionality integrates the heterogeneous networks and the broadcast network, enabling bidirectional transmissions with the client end. [0090] In addition, the client terminal may send a direct content request to the transmission control module through the 3G, LTE or Wifi wireless network and then through the Internet. This service intends to enable the client terminal to obtain content from the Internet resources directly. After receiving the request, the transmission control module provides a content service directly to the client terminal based on normal criteria (for example, the user request arriving first will be processed first), or prioritization criteria (for example, premium users and privileged users are prioritized). Similarly, the control signaling may be acceptance, waiting or no response. [0091] When the client terminal selects the 3G, LTE or Wifi access mode, in accordance with the optimal channel criterion, the client terminal evaluates the channel condition in real-time based on the 3G, LTE or Wifi return channel to select an optimal interaction mode. If the client terminal is a mobile device and a network handover is required, it follows the optimal channel criteria for handover. [0092] The terrestrial digital TV network architecture of the invention is primarily applicable to some regions with limited hardware environment, for example in rural areas, without too many obstacles and with a relatively simple channel environment. In this circumstance, the network architecture of the invention applies in two scenarios as following. [0093] When the user is near the TV tower base station and has a Light-of-Sight transmission condition, a direct return uplink may be added on the basis of the broadcast link. [0094] When the user is far from the TV tower base station, or there is no Light-of-Sight transmission between the user and the TV tower base station, a return uplink with repeaters may be added on the basis of the broadcast link. [0095] The network architectures of the invention operable in the above two scenarios are illustrated below with two embodiments. [0096] As shown in FIG. 4 , the network architecture of the invention mainly includes a TV tower base station (for example, a broadcast signal TV tower base station) and a client terminal, as well as an uplink and a downlink between the TV tower base station and the client terminal. When the user is near the TV tower base station and might be in a Light-of-Sight transmission condition, e.g., the user is located within 10 km from the broadcast TV tower base station, a direct return uplink may be added on the basis of broadcast link. [0097] The downlink and uplink utilize a combination of TDD and FDD, wherein the downlink is on a different frequency band from the uplink. The downlink carries broadcast information transmitted to all users in a broadcast mode and proprietary information specific to individual users transmitted in a broadcast or directional transmission mode. The coverage of downlink information is improved by transmitting high rate signals through transmit diversity of the TV tower base station, which is suitable for immersive applications such as SHDTV, HDTV and 3DTV, as well as Rich Media applications. The uplink is accessed according to information in a time-frequency resource table specified individually and delivered on the downlink. [0098] The uplink signal is transmitted by the client terminal in a directional transmission mode, which can be implemented by a directional antenna or through beamforming of an antenna array, thus achieving high system power efficiency, far transmission distance, and security. The modulation and demodulation for the uplink burst transmissions rely on the PSK modulation method with a relatively low peak-to-average power ratio to improve power efficiency. The uplink also employs a multi-rate Turbo convolutional coding technology, and utilizes the long preamble sequence readily to be captured. The MAC layer protocol for the uplink employs the DOCSIS protocol which has been applied in cable TVs, and employs the combined “contention and reservation” resource allocation method, wherein the contention method may be utilized for short data service like a VOD request, and the resource reservation method may be utilized for real-time video call, video interaction service, etc. The frame structure defines essential signaling frames: ranging frame and MAP frame. By division of time slots and subcarrier clusters, it is possible to support a plurality of multi-access modes, such as TDMA, OFDMA or SC-FDMA. [0099] As shown in FIG. 5 , when the user is far from the TV tower base station, for example, when the user is about 10-35 km from the broadcast TV tower base station, there is typically no Light-of-Sight (LoS) path due to occlusion. On the basis of the first embodiment, the invention employs a network architecture with wireless repeaters to extend the coverage of downlink transmissions (there may be multiple wireless repeaters, without being limited to the single repeater mode as shown in FIG. 5 ). Typically, the wireless repeater includes a pair of back-to-back wireless access points (APs), one for receiving, and the other for transmitting. [0100] In particular, the wireless repeater may use one or more of various wireless forwarding modes, such as analog intra-frequency forwarding, analog inter-frequency forwarding, digital intra-frequency forwarding, digital inter-frequency forwarding, or Bluetooth or Wifi forwarding, etc. The TV tower base station transmits a broadcast signal to the wireless repeater, which forwards the broadcast signal to the client terminal; the client terminal transmits an uplink signal to the wireless repeater, which forwards the uplink signal to the TV tower base station. [0101] Also, when there is no Light-of-Sight transmission in the uplink transmission path, the return uplink with a wireless repeater as in FIG. 5 may be employed to enable the uplink transmission between the client terminal and the TV tower base station. Selecting the coding with a low constellation and a low bit rate can further improve the uplink coverage range, thereby enhancing the capability of direct return uplink. [0102] As known from the above, the TV tower base station implementing this invention includes a receiving device (not shown) and a transmitting device (not shown), wherein the transmitting device transmits information to the client terminal at a first frequency in a broadcast mode, and the receiving device receives information transmitted from the client terminal at a second frequency. Moreover, the information transmitted from the transmitting device in the broadcast mode includes broadcast information transmitted to all users and proprietary information specific to individual users. The receiving device receives the information transmitted from the client terminal according to a time-frequency resource table for the client terminal. [0103] Meanwhile, the client terminal implementing this invention also includes a receiving device (not shown) and a transmitting device (not shown), wherein the receiving device receives information sent by the TV tower base station in a broadcast mode at a first frequency, and the transmitting device transmits information to the TV tower base station at a second frequency. Moreover, the client terminal transmits information to the TV tower base station in a directional transmission mode, which can be implemented by a directional antenna or through beamforming of an antenna array. [0104] Those skilled in the art shall appreciate that the specification above illustrates one or more of the numerous embodiments of this invention, rather than limiting thereof. Any equivalent modification, variations and equivalents to the above embodiments, that are consistent with the substantial spirit and scope of this invention, fall within the scope of the claims of this invention.

This invention discloses a digital TV broadcast system coordinated with a broadband communication network, an information transmission network in which the broadcast system is applied, a digital TV heterogeneous network architecture, and a client terminal used in each of the above network systems. The various broadcast system architectures of the invention adopt the design concept of heterogeneous network which integrates a broadcast network with other networks, for example, a communication network, the Internet and the like, to form a heterogeneous network architecture coordinating various networks. Meanwhile, the usage in bad conditions are taken into account, and a broadcast TV system which enables uplink transmission by using a broadcast link is designed. The terminal of the invention is a terminal applicable in these heterogeneous network architectures, is capable of receiving signals transmitted from various networks, and can enable flexible receiving and access modes with a series of control means. The network system and client terminal of the invention can achieve an optimized allocation of network resources, save spectrum resources, and enable optimized transmission and management of information resources.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to thiophenesulfonamides that have carbonic anhydrase inhibition activity and are useful as anti-glaucoma agents. 2. Background of the Art Glaucoma is an ocular disorder associated with elevated intraocular pressures which are too high for normal function and may result in irreversible loss of visual function. If untreated, glaucoma may eventually lead to blindness. Ocular hypertension, i.e., the condition of elevated intraocular pressure without optic nerve head damage or characteristic glaucomatous visual field defects, is now believed by many ophthalmologists to represent the earliest phase of glaucoma. Many of the drugs formerly used to treat glaucoma proved not entirely satisfactory. Indeed, few advances were made in the treatment of glaucoma since pilocarpine and physostigmine were introduced. Only recently have clinicians noted that many β-adrenergic blocking agents are effective in reducing intraocular pressure. While many of these agents are effective in reducing intraocular pressure, they also have other characteristics, e.g. membrane stabilizing activity, that are not acceptable for chronic ocular use. (S)-1-tert-Butylamino-3-[(4-morpholino-1,2,5-thiadiazol-3-yl)oxy]-2-propanol, a β-adrenergic blocking agent, was found to reduce intraocular pressure and to be devoid of many unwanted side effects associated with pilocarpine and, in addition, to possess advantages over many other β-adrenergic blocking agents, e.g., to be devoid of local anesthetic properties, to have a long duration of activity, and to display minimal tolerance. Although pilocarpine, physostigmine and the β-adrenergic blocking agents mentioned above reduce intraocular pressure, none of these drugs manifests its action by inhibiting the enzyme carbonic anhydrase and, thereby, impeding the contribution to aqueous humor formation made by the carbonic anhydrase pathway. Agents referred to as carbonic anhydrase inhibitors, block or impede this inflow pathway by inhibiting the enzyme, carbonic anhydrase. While such carbonic anhydrase inhibitors are now used to treat intraocular pressure by oral, intravenous or other systemic routes, they thereby have the distinct disadvantage of inhibiting carbonic anhydrase throughout the entire body. Such a gross disruption of a basic enzyme system is justified only during an acute attack of alarmingly elevated intraocular pressure, or when no other agent is effective. Topically effective carbonic anhydrase inhibitors are reported in U.S. Pat. Nos. 4,386,098; 4,416,890; and 4,426,388. The compounds reported therein are 5 (and 6)-hydroxy-2-benzothiazolesulfonamides and acyl esters thereof. Additionally, U.S. Pat. No. 4,544,667 discloses a series of benzofuran-2-sulfonamides, and U.S. Pat. Nos. 4,477,466; 4,486,444; 4,542,152; and 4,585,787 disclose 5-phenylsulfonylthiophene-2-sulfonamides and 5-benzoylthiophene-2-sulfonamides and alkanoyloxy derivatives thereof which are reported to be topically effective carbonic anhydrose inhibitors useful in the treatment of elevated intraocular pressure and glaucoma. Finally, U.S. Pat. No. 4,914,111 reports that thiophene or furan-2-sulfonamides, having a 4-benzyl substituent are effective for the topical treatment of elevated intraocular pressure and glaucoma. In view of the above, it is clear that a great deal of research has been carried out on the use of sulfonamides for the topical treatment of glaucoma. Furthermore, certain thiophenesulfonamides have been suggested for the topical treatment of glaucoma. However, the use of 3-thiophenesulfonamides has not been suggested for use in the topical treatment of glaucoma. Therefore, it is one objective of this invention to provide 3-thiophenesulfonamides for the treatment of glaucoma. It is another object of this invention to provide compounds having carbonic anhydrase inhibition activity. Another object of this invention is to provide a method of inhibiting carbonic anhydrase activity to thereby treat glaucoma. Other objects and advantages of the instant invention will become apparent from a careful reading of the specification below. SUMMARY OF THE INVENTION The present invention provides novel compounds having carbonic anhydrase inhibition activity and useful in the treatment of glaucoma. These compounds are represented by the structural formula: ##STR2## wherein R 1 and R 2 are independently (a) hydrogen; or (b) OR 4 , wherein R 4 is hydrogen or C 1-7 alkyl or C 1-3 alkylcarbonyl or phenylcarbonyl or phenyl; or (c) NR 5 R 6 , wherein R 5 and R 6 are independently hydrogen, or C 1-7 alkyl, or C 1-7 alkyl substituted with one or more halogen or OR 4 ; or (d) --COR 7 , wherein R 7 is hydrogen, C 1-7 alkyl, or NR 5 R 6 ; or (e) --SR 8 , wherein R 8 is hydrogen or C 1-7 alkyl, or C 1-7 alkyl substituted with one or more halogen, or OR 4 ; or (f) C 1-7 alkyl, or C 1-7 alkyl substituted with one or more halogen, or OR 4 or NR 5 R 6 ; or (g) R 1 and R 2 are together (i) ═O, or (ii) ═NOR 8 , or (iii) ═S; and R 3 is (h) C 1-7 alkyl or C 1-7 substituted with one or more halogen, OR 4 or NR 5 R 6 ; or (i) aryl, wherein said aryl comprises up to 10 carbon atoms and is an unsubstituted carbocyclic aryl or heterocyclic aryl, which may be selected from the group consisting of phenyl, thienyl, furyl, pyridyl, pyrryl, piperidyl, pyrrolidyl, morpholinyl, or said carbocyclic aryl or heterocyclic aryl is substituted with one or more halogen, or OR 4 , or NR 5 R 6 , or carboxylic acid or lower alkyl esters thereof, or carboxaldehyde or C 1-7 alkyl, or C 1-7 alkyl substituted with one or more halogen, or OR 4 , or NR 5 R 6 or carboxylic acid or lower alkyl esters thereof; or (j) --COR 9 , wherein R 9 is R 7 or a carbocyclic or a heterocyclic radical, e.g. aryl, wherein said carbocyclic or a heterocyclic radical comprises up to 10 carbon atoms and may be selected from the group consisting of phenyl, cyclopentyl, cyclohexyl, thienyl, furyl, pyridyl, pyrryl, piperidyl, pyrrolidyl, morpholinyl or said carbocyclic aryl or heterocyclic aryl radical is substituted with one or more halogen, or OR 4 , or NR 5 R 6 , or C 1-7 or C 1-7 alkyl substituted with one or more halogen, OR 4 or NR 5 R 6 . Preferably, in the novel compounds of the invention R 1 and R 2 , together, represent O; or at least one of R 1 or R 2 is hydrogen and the other is OH, OCOCH 3 , NOH, or H. (That is, the novel compounds of this invention may include an alpha carbonyl or hydroxy, or acetoxy, or hydroxyamino, etc. group at the 5 position on the thiophene ring.) R 3 preferably represents C 1 to C 6 alkyl or phenyl or phenyl substituted with one or more, more preferably one, hydroxy, methoxy, acetoxy, acetoxymethylene, carboxy, hydroxymethyl, formyl, N,N-dimethylaminomethyl fluoro, chloro or bromo radicals. DETAILED DESCRIPTION OF THE INVENTION The novel compounds of the invention may be prepared by the following general reaction scheme: 4-Bromo-2-thiophenecarboxaldehyde is reacted with R 3 Li or R 3 MgX, wherein X is a halogen, e.g., bromo or iodo, in tetrahydrofuran, or any other dipolar, aprotic solvent, e.g. diethylether, dioxane, etc., at a temperature of from about 0° C. to -78° C., to yield an alkoxide of the addition product. This intermediate is reacted with trimethylsilylchloride, at a temperature of from about 0° C. to -78° C., to provide a "protected" alcohol. The protected intermediate is consecutively reacted with n-Butyllithium in tetrahydrofuran at a temperature of about -100° C. to yield the 3-lithio compound. The lithio compound is reacted with SO 2 at a temperature of about -100° C. in THF, or other aprotic solvent, to yield the lithio sulfinate. The lithium sulfinate is reacted with N-chloro succinimide (NCS) at ambient temperatures in dichloromethane to yield the sulfonyl chloride. The sulfonyl chloride is consecutively reacted with NH 4 OH and tetra-n-butyl ammonium fluoride to yield a novel compound of the invention represented by the general formula: ##STR3## I may be oxidized by Jones' reagent to yield a novel compound of the invention represented by the general formula: ##STR4## That is, II represents the alpha carbonyl derivatives of the invention, i.e., wherein R 1 and R 2 together, represent O (oxygen). II may be reacted with H 2 NOH.HCl in pyridine to provide compounds of the invention represented by the general formula: ##STR5## That is, in the compounds represented by Formula III, R 1 and R 2 , together, represent NOH. Alternatively, compounds represented by Formula I may be reacted with acetic anhydride in pyridine to yield compounds of the invention represented by the general formula: ##STR6## That is, in the compounds represented by Formula IV, R 1 represents OCOCH 3 and R 2 represents hydrogen. Of course, other anhydrides may be used, e.g. benzoic anhydride, to provide compounds wherein R 1 represents a radical derived from said other anhydride, e.g. R 1 is OCOC 6 H 5 . An alternative to the above general reaction scheme relies on the Wittig reaction as follows: (Alkyl)triphenylphosphonium bromide is reacted with 4-bromo-2-thiophene carboxaldehyde in THF, in the presence of potassium tertiary butoxide to yield ##STR7## wherein R is an unsaturated alkenyl radical derived from the above alkyl phosphonium bromide. The 2-(alk-1-enyl)-4-bromothiophene of Formula V may be hydrogenated in the presence of Wilkenson's catalyst to yield the saturated derivative. The saturated derivative is consecutively reacted with n-butyl lithium, SO 2 , NCS and NH 4 OH/tetra-n-butyl ammoniumfluoride to yield ##STR8## wherein R 1 =R 2 =H and R 3 is alkyl. Specific compounds within the scope of this invention include: 1-[5-(3-sulfamoyl thienyl)] pentanone oxime 5-(4-hydroxybenzoyl)3-thiophene sulfonamide 5-(3-N,N-dimethylamino-4-hydroxybenzhydrol)-3-thiophene sulfonamide 5-(1-hydroxy-n-pentyl)-3-thiophene sulfonamide 5-(1-hydroxy-n-heptyl)-3-thiophene sulfonamide 5-(4-acetoxymethylbenzhydrol)-3-thiophene sulfonamide 5(4-formylbenzhydrol)-3-thiophene sulfonamide 5-(4-carboxylbenzhydrol)-3-thiophene sulfonamide 5-(benzhydrol)-3-thiophene sulfonamide 5-(4-methoxybenzhydrol)3-thiophene sulfonamide 5-(2-methoxybutyl)-3-thiophene sulfonamide 5-(4-chlorohexyl)-3-thiophene sulfonamide 5-(3-phenylpentyl)-3thiophene sulfonamide 5-(3-methylpentyl)-3-thiophene sulfonamide 5-benzoyl-3-thiophene sulfonamide 5-[benzhydrol]-3-thiophene sulfonamide When administered for the treatment of elevated intraocular pressure of glaucoma, the active compound is most desirably administered topically to the eye, although systemic treatment is also satisfactory. When given systemically, the drug can be given by any route, although the oral route is preferred. In oral administration the drug can be employed in any of the usual dosage forms such as tablets or capsules, either in a contemporaneous delivery or sustained release form. Any number of the usual excipients or tableting aids can likewise be included. The active drug of this invention is most suitably administered in the form of ophthalmic pharmaceutical compositions adapted for topical administration to the eye such as a suspension, ointment, or as a solid insert. Formulations of these compounds may contain from 0.01 to 15% and especially 0.5% to 3% of medicament. Higher dosages as, for example, about 10%, or lower dosage can be employed provided the dose is effective in reducing or controlling elevated intraocular pressure. As a unit dosage from 0.001 to 10.0 mg, preferably 0.005 to 2.0 mg, and especially 0.1 to 1.0 mg of the compound is generally applied to the human eye, generally on a daily basis is single or divided doses so long as the condition being treated exists. The hereinbefore described dosage values are believed accurate for human patients and are based on the known and presently understood pharmacology of the compounds, and the activity of other similar entities in the human eye. As with all medications, dosage requirements are variable and must be individualized on the basis of the disease and the response of the patient. The pharmaceutical preparation which contains the active compound may be conveniently admixed with a non-toxic pharmaceutical organic carrier, or with a non-toxic pharmaceutical inorganic carrier. Typical of pharmaceutically acceptable carriers are, for example, water, mixtures of water and water-miscible solvents such as lower alkanols or aralkanols, vegetable oils, polyalkylene glycols, petroleum based jelly, ethyl cellulose, ethyl oleate, carboxymethylcellulose, polyvinylpyrrolidone, isopropyl myristrate and other conventionally employed acceptable carriers. The pharmaceutical preparation may also contain non-toxic auxiliary substances such as emulsifying, preserving, wetting agents, bodying agents and the like, as for example, polyethylene glycols, antibacterial components such as quaternary ammonium compounds, phenylmercuric salts known to have cold sterilizing properties and which are non-injurious in use, thimerosal, methyl and propyl paraben, benzyl alcohol, buffering ingredients such as sodium chloride, sodium borate, sodium acetate, and other conventional ingredients such as sorbitan monolaurate, polyoxyethylene sorbitan monopalmitylate, dioctyl sodium sulfosuccinate, monothioglycerol, thiosorbitol, ethylenediamine tetracetic acid, and the like. Additionally, suitable ophthalmic vehicles can be used as carrier media for the present purpose including conventional phosphate buffer vehicle systems, isotonic boric acid vehicles, isotonic sodium chloride vehicles, isotonic sodium borate vehicles and the like. The pharmaceutical preparation may also be in the form of a solid insert. While many patients find liquid medication to be entirely satisfactory, other may prefer a solid medicament that is topically applied to the eye, for example, a solid dosage form that is suitable for insertion into the cul-de-sac. To this end the carbonic anhydrase inhibiting agent can be included with a non-bioerodable insert, i.e., one which after dispensing the drug remains essentially intact, or a bioerodable insert, i.e., one that either is soluble in lacrimal fluids, or otherwise disintegrates. For example, one may use a solid water soluble polymer as the carrier for the medicament. The polymer used to form the insert may be any water soluble non-toxic polymer, for example, cellulose derivatives such as methylcellulose, sodium carboxymethyl cellulose, or a hydroxy lower alkyl cellulose such as hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose and the like; acrylates such as polyacrylic acid salts, ethyl acrylates, polyacrylamides; natural products such as gelatin, alginates, pectins, tragacanth, karaya, chondrus, agar, acacia; the starch derivatives such as starch acetate, hydroxyethyl starch ethers, hydroxypropyl starch, as well as other synthetic derivatives such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl methyl ether, polyethylene oxide, neutralized carbopol and xanthan gum, and mixtures of said polymers. The invention is further illustrated by the following examples which are illustrative of a specific mode of practicing the invention and is not intended as limiting the scope of the appended claims. EXAMPLE 1 2-(n-Hex-1-enyl)-4-bromo thiophene 2.0 grams (10.5 mmols) of (n-pentyl) triphenyl phosphonium bromide was added to 105 ml. of tetrahydrofuran (THF) with stirring. 1.86 gms (15.8 mmol.) of potassium tertiary butoxide was then added to the mixture while stirring at room temperature under an argon atmosphere. After one hour of continued stirring, 2.0 gms (10.5 mmol) of 4-bromo-2-thiophene carboxaldehyde, dissolved in 20 ml of THF, was added to the phosphonium bromide solution. After an additional one hour, the reaction was quenched with water. The organic layer was then separated, washed twice with water and then with brine. After drying over MgSO 4 and filtering, the filtrate was concentrated. The concentrate was flushed through a silica plug and eluted with hexane to yield 2.2 gms of a yellow liquid. This liquid included a mixture of cis and trans isomers of the named compound and had the following NMR spectra: 1 HNMR (CDCl 3 ): 7.12 (s), 6.98 (s), 6.88 (s), 6.42 (app. d), 6.03-6.14 (m), 5.52-5.64 (m), 2.32-2.42 (m), 2.12-2.22 (m), 1.28-1.74 (m), 0.90-0.98 (m). EXAMPLE 2 2-(hexyl)-4-bromo thiophene 2.2 gms (9.0 mmol) of the product of Example 1 were dissolved in 25 ml of ethanol and 0.22 gms of Wilkenson's catalyst were added. (Wilkenson's catalyst is tris(triphenylphosphine) rhodium (I) chloride.) The mixture was stirred at room temperature under atmospheric hydrogen pressure overnight. The reaction product was concentrated and separated by flash chromatography, using hexane, as the eluant, to yield 2.2 gms of a colorless liquid. The NMR spectra of said liquid was as follows: 1 HNMR (CDCl 3 ): 7.01 (s), 6.98 (s), 6.78 (s), 6.71 (s), 6.42 (d, J=15 Hz), 6.09 (d, t, J=8, 15 Hz), 2.77 (t, J=7 Hz), 2.12-2.22 (m), 1.60-1.70 (m), 1.29-1.35 (m), 0.87-0.91 (m). From said spectra it was determined that 2-(n-hex-1-enyl)-4-bromothiophene was still present in the reaction product. The reaction product was again treated with Wilkenson's Catalyst and hydrogen, overnight. The re-treated reaction mixture was passed through a silica gel plug and eluted with hexane to yield 2.1 gms of a clear, colorless liquid having the following NMR spectra: 7.01 (s, 1H), 6.71 (s, 1H), 2.77 (t=7 Hz, 2H), 1.65 (m, 2H), 1.29-1.35 (m, 6H), 0.89 (t, J=7 Hz, 3H). EXAMPLE 3 5-n-Heptyl-3-thiophene sulfonamide 1.93 gms (7.8 mmol) of the bromothiophene of Example 2 were added to 78 ml. of THF and the solution was cooled to -100° C., while under an argon atmosphere. 4.9 ml of a 1.6M solution of n-butyl lithium (n-BuLi) in hexane were added to the cooled solution and stirred at -100° C. under an argon atmosphere. After a few minutes, SO 2 was bubbled into the solution. When the solution became saturated with SO 2 , it was allowed to warm to room temperature and 20 ml. of ethyl ether were then added. After about two and one-half hours, the solution was transferred to a roto-evaporator and concentrated. The resulting concentrate was dissolved in 78 ml of methylene dichloride (CH 2 Cl 2 ) and 1.15 gms (8.6 mmol) of N-chlorosuccinamide (NCS) were added. The resulting mixture was stirred, under argon, at room temperature for two hours. The resulting mixture was filtered and the filtrate was concentrated. The concentrate was dissolved in 50 ml of acetone and 10 ml of concentrate NH 4 OH (aqueous) were added. After 10 minutes, the mixture was diluted with ethyl acetate and washed with water three times and then with a saturated salt solution, i.e. brine. The organic phase was separated, dried over MgSO 4 , filtered and the filtrate concentrated. The concentrate was subjected to flash chromatography utilizing a 3 to 1, by volume, mixture of hexane and ethyl acetate eluant to yield 1.24 gms of a light yellow solid having the following NMR spectra: 1 H NMR (CDCl 3 ): 7.76 (d, J=1.4 Hz, 1H), 7.07 (d, J=1.4 Hz, 1H), 5.21 (bs, 2H), 2.76 (q, J=7.7 Hz, 2H), 1.65 (p, J=7.7 Hz, 2H), 1.28-1.38 (m, 6H), 0.87 (t, J=6.8 Hz, 3H). EXAMPLE 3(a) 5-n-Pentyl-3-thiophene sulfonamide The reactions set forth in Examples 1 through 3 are repeated except that (n-butyl)triphenylphosphine bromide is substituted for (n-pentyl)triphenylphosphine bromide to yield the named compound. EXAMPLE 3(b) 5-(3-methylpentyl)-3-thiophene sulfonamide The reactions set forth in Examples 1 through 3 are repeated except that (2-methylbutyl)triphenylphosphine bromide is substituted for (n-pentyl)triphenylphosphine bromide to yield the named compound. EXAMPLE 3(c) 5-(3-phenylpentyl)-3-thiophene sulfonamide The reactions set forth in Examples 1 through 3 are repeated except that (2-phenylbutyl)triphenylphosphine bromide is substituted for (n-pentyl)triphenylphosphine bromide to yield the named compound. EXAMPLE 3(d) 5-(4-chlorohexyl)-3-thiophene sulfonamide The reactions set forth in Examples 1 through 3 are repeated except that (3-chloropentyl)triphenylphosphine bromide is substituted for (n-pentyl)triphenylphosphine bromide to yield the named compound. EXAMPLE 3(e) 5-(2-methoxybutyl)-3-thiophene sulfonamide The reactions set forth in Examples 1 through 3 are repeated except that (3-methoxypropyl)triphenylphosphine bromide is substituted for (n-pentyl)triphenylphosphine bromide to yield the named compound. EXAMPLE 4 5-[(4-t-butyldimethylsiloxyphenyl)(trimethylsiloxy)methyl]-3-bromothiophene 5.9 gms (0.02 mol) of 4-bromo t-butyldimethylsiloxybenzene were dissolved in 42 ml of dry THF. The solution was cooled to -78° C. while under an argon atmosphere and 13.1 ml (0.02 mol) of a 1.6M solution of n-butyl lithium in hexane were added. After stirring for fifteen minutes under argon the solution was combined over a twenty-five-minute period with a solution of 4.0 gms (0.02 mol) of 4-bromo-2-thiophene carboxaldehyde in 50 ml. of THF at -78° C. The resulting solution was stirred for one hour and fifteen minutes at -78° C. 1.95 ml of trimethylsilylchloride (TMSCI) were added and the solution was allowed to warm to room temperature overnight with stirring. An additional 10 ml of TMSCl were added and the solution was stirred for six hours. The reaction was quenched with water; the organic phase was separated from the brine, dried over MgSO 4 , filtered, concentrated and separated by flash chromatography, utilizing hexane as the eluant. 2.5 gms of a clear colorless liquid were recovered having an NMR spectra of: 1 H NMR (acetone-d 6 ): 7.21 (d, J=8.5 Hz, 2H), 7.11 (d, J=1.5 Hz, 1H), 6.80 (d, J=8.5 Hz, 2H), 6.65 (d, J=1.5 Hz, 1H), 5.84 (s, 1H), 0.99 (s, 3H), 0.21 (s, 6H), 0.10 (s, 9H). EXAMPLE 5 5-(4-hydroxybenzhydrol)3-thiophene sulfonamide 2.34 gms (5.0 mmol) of the bromothiophene, prepared in Example 4, were dissolved in 50 ml of dry THF. The resulting solution is cooled to -78° C. while under an argon atmosphere. 3.1 ml of a 1.6M solution of n-BuLi, in hexane, is added and stirring was continued for a few minutes. SO 2 was bubbled into the solution until the solution was saturated with SO 2 . 20 ml of ethyl ether were added and the solution was allowed to warm to room temperature. After about two hours at room temperature, the solution was concentrated, the residue dissolved in 50 ml of methylene dichloride and 0.73 gms (5.5 mmol) of NCS were added. After about one-half hour, the resulting mixture was filtered, the filtrate concentrated and the concentrate was dissolved in a solution of 5 ml concentrated NH 4 OH (aqueous) and 25 ml of acetone. After one-half hour, the resulting solution is diluted with ethyl acetate, washed with water, three times, and then with brine. The resulting organic phase is separated, dried over MgSO 4 , filtered and the filtrate concentrated. The concentrate was subjected to flash chromatography utilizing a 3:1 mixture of hexane and ethyl acetate, as the eluant, to yield 1.41 gms of a light yellow oil having the following NMR spectra: 1 H NMR (acetone-d 6 ): 7.88 (s, 1H), 7.33 (d, J=9 Hz, 2H), 7.10 (s, 1H), 6.88 (d, J=9 Hz, 2H), 6.55 (bs, 2H), 6.07 (s, 1H), 0.97 (s, 9H), 0.20 (s, 6H), 0.07 (s, 9H). 0.52 gms (1.1 mmol.) of the product light yellow oil was dissolved in 11 ml of THF and 2.3 ml of a 1.0M solution of tetra-n-butyl ammonium fluoride (TBAF) in THF is added. After one-half hour, the reaction was quenched with water and extracted with ethyl acetate. The organic layer was separated, washed three times with water and then with brine. The organic phase was separated, dried over MgSO 4 , filtered and the filtrate concentrated. The concentrate was subjected to flash chromatography, utilizing the above hexane/ethyl acetate mixture to yield 0.26 gms of a white foam having the following NMR spectra: 1 H NMR (acetone-d 6 ): 8.43 (bs, 1H), 7.88 (s, 1H), 7.28 (d, J=9 Hz, 2H), 7.05 (s, 1H), 6.82 (d, J=9 Hz, 2H), 6.57 (bs, 2H), 5.95 (s, 1H), 5.32 (bs, 1H). EXAMPLE 5(a) 5-(4-methoxybenzhydrol)-3-thiophene sulfonamide The reactions set forth in Examples 4 and 5 are repeated except that 4 -methoxybromobenzene is substituted for 4-bromo t-butyldimethyl-siloxy-benzene to yield the named compound which has the following NMR spectra: 1 H NMR (acetone-d 6 ): 7.88 (d, J=1.5 Hz, 1H), 7.38 (d, J=8.6 Hz, 2H), 7.07 (m, 1H), 6.92 (d, J=8.6 Hz, 2H), 6.54 (bs, 2H), 5.99 (d, J=4.3 Hz, 1H), 5.34 (d, J=4.3 Hz, 1H), 3.78 (s, 3H). EXAMPLE 5(b) 5-(benzhydrol)-3-thiophene sulfonamide The reactions set forth in Examples 4 and 5 are repeated except that bromobenzene is substituted for 4-bromo t-butyldimethylsiloxybenzene to yield the named compound. This compound may be subsequently reacted with acetic anhdyride in the presence of pyridine, as described above, to yield the acylated derivative, i.e. 5-[(phenyl)(acetoxy)methyl]-3-thiophene sulfonamide, having the following NMR spectra: 1 H NMR (acetone-d 6 ): 7.90 (s, 1H), 7.30-7.50 (m, 5H), 7.10 (s, 1H), 6.55 (bs, 2H), 6.05 (d, J=4.3 Hz, 1H), 5.46 (d, J=4.3 Hz, 1H). EXAMPLE 5(c) 5-(1-hydroxy-n-heptyl)-3-thiophene sulfonamide The reactions set forth in Examples 4 and 5 are repeated except that 1-bromohexane is substituted for 4-bromo t-butyldiimethylsiloxybenzene to yield the named compound, having the following NMR spectra: 1 H NMR (CDCl 3 ): 7.88 (s, 1H), 7.24 (s, 1H), 5.06 (bs, 2H), 4.88-4.89 (m, 1H), 2.43-2.45 (m, 1H), 1.79-1.81 (m, 2H), 1.25-1.31 (m, 8H), 0.86-0.88 (m, 3H). EXAMPLE 5(d) 5-(1-hydroxy-n-pentyl)-3-thiophene sulfonamide The reactions set forth in Examples 4 and 5 are repeated except that 1-bromobutane is substituted for 4-bromo t-butyldimethylsiloxybenzene to yield the named compound, having the following NMR spectra: 1 H NMR (CDCl 3 ): 7.82 (s, 1H), 7.20 (s, 1H), 5.35 (bs, 2H), 4.80 (t, J=4.5 Hz, 1H), 1.70-2.88 (m, 2H), 1.24-1.48 (m, 4H), 0.88 (t, J=4.5 Hz, 3H). EXAMPLE 5(e) 5-(3-hydroxybenzhydrol)-3-thiophene sulfonamide The reactions set forth in Examples 4 and 5 are repeated except that 3-bromo t-butyldimethylsiloxy is substituted for 4-bromo t-butyldi-methylsiloxybenzene to yield the named compound, having the following NMR spectra: 1 H NMR (acetone-d 6 ): 8.40 (bs, 1H), 7.89 (d, J=1.5 Hz, 1H), 7.18 (t, J=7.7 Hz, 1H), 7.11 (d, J=1.5 Hz, 1H), 6.92-6.97 (m, 2H), 6.75-6.78(m, 1H), 6.56 (bs, 2H), 5.97 (s, 1H), 5.40 (bs, 1H). EXAMPLE 6 5-(4-hydroxybenzoyl)-3-thiophene sulfonamide 0.10 gms (0.35 mmol) of 5-(4-hydroxybenzhydrol) 3-thiphene sulfonamide, as prepared in Example 5, were dissolved in 5 ml of acetone and to this solution 0.13 ml (0.35 mmol) of a 2.67M solution of Jones' Reagent were added. (Jones' Reagent is aqueous chromic acid.) The resulting mixture was stirred for about forty minutes at room temperature and then quenched with isopropyl alcohol. The resulting solution was diluted with ethyl acetate, washed three times with water and then with brine. The organic layer was separated, dried over MgSO 4 , filtered and the filtrate concentrated. The concentrate was subjected to flash chromatography, utilizing a 1:1 mixture of hexane and ethyl acetate, as the eluant, to yield 78 mg of a clear colorless oil having the following NMR spectra: 1 H NMR (acetone-d 6 ): 9.45 (bs, 1H), 8.43 (d, J=1.3 Hz, 1H), 7.95 (d, J=1.3 Hz, 1H), 7.89 (d, J=9 Hz, 2H), 7.04 (d, J=9 Hz, 2H), 6.81 (bs, 2H). EXAMPLES 6(a)-(j) The compounds of Examples 5(a)-(j) are converted into the corresponding alpha carbonyl derivatives by the method of Example 6. The compounds were identified by the NMR spectra given below. EXAMPLE 6(a) 5-(4-methoxybenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.43 (s, 1H), 7.92-7.95 (m, 3H), 7.12 (d, J=9.0 Hz, 2H), 6.77 (bs, 2H), 3.93 (s, 3H). EXAMPLE 6(b) 5-benzoyl-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.48 (s, 1H), 7.90-7.95 (m, 3H), 7.60-7.75 (m, 3H), 6.80 (2H). EXAMPLE 6(c) 5-(1-heptanoyl)-3-thiophene sulfonamide 1 H NMR (CDCl 3 ): 8.21 (s, 1H), 7.94 (s, 1H), 5.01 (bs, 2H), 2.89 (t, J=7.3 Hz, 2H), 1.73 (p, 7.2 Hz, 2H), 1.30-1.34 (m, 6H), 0.88 (t, J=8.3 Hz, 3H). EXAMPLE 6(d) 5-(1-pentanoyl)-3-thiophene sulfonamide 1 H NMR (CDCl 3 ): 8.22 (s, 1H), 7.96 (s, 1H), 5.10 (bs, 2H), 2.90 (t, J=7.5 Hz, 2H), 1.73 (p, J=7.5 Hz, 2H), 1.40 (sex., J=7.5 Hz, 2H), 0.95 (t, J=7.5 Hz, 3H). EXAMPLE 6(e) 5-(3-hydroxybenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.46 (d, J=1.3 Hz, 1H), 7.93 (d, J=1.4 Hz, 1H), 7.32-7.46 (m, 3H), 7.15-7.19 (m, 1H), 6.86 (bs, 2H). Examples 6(f) to (j) were prepared by a process analogous to the preparation of Examples 6(a) to (e) with the appropriate bromo reactant substituted for the 4-bromotrimethylsiloxybenzene. EXAMPLE 6(f) 5-(4-butylbenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.45 (d, J=1.4 Hz, 1H), 7.93 (d, J=1.4 Hz, 1H), 7.85 (d, J=8.2 Hz, 2H), 7.45 (d, J=8.2 Hz, 2H), 6.78 (bs, 2H), 2.74 (t, J=7.5 Hz, 2H), 1.60-1.68 (m, 2H),. 1.38 (sex., J=7.8 Hz, 2H), 0.93 (t, J=7.3 Hz, 3H). EXAMPLE 6(g) 5-(3-trifluoromethylbenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.52 (d, J=1.4 Hz, 1H), 8.22 (d, J=7.9 Hz, 1H), 8.17 (s, 1H), 8.06 (d, J=8.3 Hz, 1H), 7.95 (d, J=1.4 Hz, 1H), 7.88 (t, J=7.8 Hz, 1H), 6.78 (bs, 2H). EXAMPLE 6(h) 5-(2-fluorobenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.50 (d, J=1.2 Hz, 1H), 7.79 (t, J=1.5 Hz, 1H), 7.68-7.73 (m, 2H), 7.34-7.44 (m, 2H), 6.80 (bs, 2H). EXAMPLE 6(i) 5-(3-fluorobenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.49 (s, 1H), 7.95 (s, 1H), 7.60-7.77 (m, 3H), 7.47-7.53 (m, 1H), 6.79 (bs, 2H). EXAMPLE 6(j) 5-(3.5-difluorobenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.51 (s, 1H), 7.99 (s, 1H), 7.49-7.56 (m, 2H), 7.37-7.44 (m, 1H), 6.79 (bs, 2H). EXAMPLE 7 5-(4-hydroxy-3-(N,N-dimethylaminomethyl)benzoyl)-3-thiophene sulfonamide 5-(4-hydroxy-3,5-(bis-N,N-dimethylaminomethyl)benzoyl)-3-thiophene sulfonamide 0.25 g (0.88 mmol) of 5-(4-hydroxybenzoyl)-3-thiophene sulfonamide, 0.21 mL (2.6 mmol)of aqueous formaldehyde (37%) and 0.89 mL (7.9 mmol)of aqueous dimethylamine (40%) were added to 3 mL of ethanol. The solution was heated at reflux for 15 1/2 h and then cool to room temperature. Solvent was removed under vacuum and the crude product subjected to flash chromatography. Utilizing 5:1 chloroform/methanol as the eludent 49 mg of 5-(4-hydroxy-3-(N,N-dimethylaminomethyl)benzoyl)-3-thiophene sulfonamide was recovered as a yellow color solid. 1 H NMR (acetone-d 6 ): 8.39 (d, J=1.4 Hz, 1H), 7.92 (d, J=1.4 Hz, 1H), 7.81 (dd, J=8.5, 2.3 Hz, 1H), 7.67 (d, J=2.3 Hz, 1H), 6.85 (d, J=8.5 Hz, 1H), 3.82 (s, 2H), 2.38 (s, 6H). The eluant was switched over to 2:1 methanol/chloroform (with 5% triethylamine) and 0.18 g of 5-(4-hydroxy-3,5-(bis-N,N-dimethylamino-methyl)benzoyl)-3-thiophene sulfonamide was recovered as a yellow color solid. 1 H NMR (acetone-d 6 ): 8.39 (d, J=1.4 Hz, 1H), 7.93 (d, J=1.4 Hz, 1H), 7.75 (s, 2H), 3.66 (s, 4H), 2.32(s, 12H). EXAMPLE 8 4-bromo-2-[tetrahydropyronyl) (4-t-butyldimethylsiloxymethylphenyl)methyl] thiophene 6.5 g (22 mmol) of 4-bromobenzyl alcohol, t-butyldimethylsilyl ether was added to 40 mL of THF. The solution was cool to -78° C. 15.3 mL (22 mmol) of a 1.42M n-BuLi solution was added. The solution was transferred via cannula to 4.2 g (22 mmol) of 4-bromo-2-thiophene carboxaldehyde in 70 mL THF at -78° C. Reaction was stirred at -78° C. for 30 min before quenching with 5 mL of saturated NH 4 Cl. The reaction was diluted with ethyl acetate and washed with water (3×) followed with brine. Solution was dried over MgSO 4 and the solvent removed under vacuum. The product, 10 mL (o.11 mol) of DHP and a catalytic amount of TsOH were added to 88 mL of dichloromethane. The reaction was stirred at rt for 18 1/2 h. The reaction was washed with water (3×) followed with brine. The solution was dried over MgSO 4 and the solvent removed under vacuum. Flash chromatography utilizing 20:1 hexane/ethyl ether as the eluant recovered 9.3 g of the product as a light yellow color oil. 1 H NMR (CDCl 3 ): mixture of diastereomers; 7.27-7.40 (m), 7.12-7.18 (m), 6.90 (s), 6.58 (s), 5.95 (s), 5.90 (s), 4.84-4.88 (m), 4.75 (s), 4.72 (s), 4.62-4.66 (m), 3.96-4.05 (m), 3.74-3.82 (m), 3.48-3.62 (m), 1.48-2.02 (m), 0.94 (s), 0.93 (s), 0.12 (s), 0.10 (s). EXAMPLE 9 5-[(tetrahydropyranyl)(4-t-butyldimethylsiloxymethylphenyl)methyl]-3-thiophene sulfonamide 8.8 g (18 mmol) of the product obtained in Example #8 was added to 180 mL of THF. The solution was cool to -100° C. 12.7 mL (18 mmol) of a 1.42M n-BuLi solution was added dropwise. After a few minutes SO 2 was passed through the reaction flask until the solution became saturated. 30 mL of ethyl ether was added and the liquid nitrogen/ethyl ether bath removed. After 2 h the solvent was removed under vacuum. The crude product and 2.6 g (19.8 mmol) NCS were added to 180 mL of dichloromethane. After stirring at rt for 11/2 h the mixture was filtered and the filtrate concentrated. The crude product was added to 30 mL of concentrated ammonium hydroxide in 180 mL of acetone. Upon stirring for 31/2 h the solution was dilutd with ethyl acetate and washed with water (3×) followed with brine. The solution was dried over MgSO 4 and the solvent removed under vacuum. Flash chromatography utilizing 2:1 hexane/ethyl acetate recovered 2.9 g of the product as a yellow color oil. 1 H NMR (CDCl 3 ): mixture of diastereomers; 7.96 (s), 7.94 (s), 7.49-7.34 (m), 7.01 (s), 6.07 (s), 6.01 (s), 4.83-4.86 (m), 4.78 (s), 4.60-4.64 (m), 3.90-3.99 (m), 3.68-3.77 (m), 3.43-3.58 (m), 1.43-1.98 (m), 0.96 (s), 0.15 (s), 0.13 (s). EXAMPLE 10 5-(4-hydroxymethylbenzhydrol)-3-thiophene sulfonamide 0.36 g (0.72 mmol) of the product from Example #9 and a catalytic amount of TsOH were added to 10 mL of methanol. After 2 h of stirring at rt the solution was diluted with ethyl acetate and washed with water (3×) followed with brine. The solution was dried over MgSO 4 and the solvent removed under vacuum. Flash chromatography utilizing 2:1 ethyl acetate/hexane as the eluant recovered 87 mg of 5-(4-hydroxymethylbenzhydrol)-3-thiophene sulfonamide as a clear colorless oil. 1 H NMR (acetone-d 6 ): 7.88 (d, J=1.4 Hz, 1H), 7.44 (d, J=7.5 Hz, 2H), 7.35 (d, J=7.5 Hz, 2H), 7.08 (d, J=1.4 Hz, 1H), 6.54 (bs, 2H), 6.04 (d, J=4.3 Hz, 1H), 5.42 (d, J=4.3 Hz, 1H), 4.62 (d, J=5.7 Hz, 2H), 4.19 (t, J=5.8 Hz, 1H). EXAMPLE 11 5-(4-carboxybenzoyl)-3-thiophene sulfonamide 0.53 g (1.8 mmol) of 5-(4-hydroxymethylbenzhydrol)-3-thiophene sulfonamide was added to 8.8 mL of acetone. The solution was cool to 0° C. and 1.35 mL (3.7 mmol) of Jone's reagent was added. After 15 min the solvent was removed under vacuum and the mixture filtered. The solid was washed with water. Flash chromatography utiling 20% methanol/chloroform as the eluant recovered 0.48 g of 5-(4-carboxybenzoyl)-3-thiophene sulfonamide as a white solid. 1 H NMR (acetone-d 6 ): 8.51 (d, J=1.4 Hz, 1H), 8.23 (d, J=8.3 Hz, 2H), 8.01 (d, J=8.3 Hz, 2H), 7.94 (d, J=1.4 Hz, 1H),6.79 (bs, 2H). EXAMPLE 11(a) 5-(3-carboxylbenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.51 (d, J=1.4 Hz, 1H), 8.50 (s, 1H), 8.34 (d, t, J=7.8, 1.3 Hz, 1H), 8.16 (d, t, J=7.8, 1.3 Hz, 1H), 7.96 (d, J=1.3 Hz, 1H), 7.77 (t, J=7.8 Hz, 1H), 6.81 (bs, 2H). EXAMPLE 12 5-[(tetrahydropyranyl)(4-hydroxymethylphenyl)methyl]-3-thiphene sulfonamide 0.45 g (0.91 mmol) of the product from Example #9 was added to 10 mL of THF. 1.0 mL (1.0 mmol) of a 1M tetra-n-butylammonium fluoride solution was added. After stirring at rt for 1 h the solution was diluted with water and extracted with ethyl acetate. The organic phase was washed with water (3×) followed with brine. The solution was dried over MgSO 4 and the solvent removed under vacuum. Flash chromatography utilizing 1:1 hexane/ethyl acetate as the eluent recovered 0.33 g of the product as a clear colorless oil. 1 H NMR (acetone-d 6 ): mixture of diastereomers; 7.97 (s), 7.95 (s), 7.32-7.48 (s), 6.97 (s), 6.60 (bs), 6.55 (bs), 6.05 (s), 5.98 (s), 4.82-4.85 (m), 4.58-4.68 (m), 4.17-4.28 (m), 3.90-3.97 (m), 3.68-3.75 (m), 3.40-3.56 (m), 1.44-1.98 (m). EXAMPLE 13 5-(4-acetoxymethylbenzhydrol)-3-thiophene sulfonamide 0.74 g (1.9 mmol) of the product from Example #12, 0.23 mL (2.9 mmol) of pyridine and 0.23 mL (2.9 mmol) of acetic anhydride were added to 19 mL of dichloromethane. After stirring at rt for 15 h the solution was diluted with ethyl acetate and washed with water (3×) followed with brine. The solution was dried over MgSO 4 and the solvent removed under vacuum. The 0.60 g of the crude product and a catalytic amount of TsOH were added to 14 mL of methanol. After stirring at rt for 31/2 h the solution was diluted with water and extracted with ethyl acetate. The organic phase was washed with water (2×) followed with brine. The solution was dried over MgSO 4 and the solvent removed under vacuum. Flash chromatography utilizing 1:1 hexane/ethyl acetate as the eluant recovered 0.37 g of 5-(4-acetoxymethyl-benzhydrol)-3-thiophene sulfonamide as a clear colorless oil. 1 H NMR (acetone-d 6 ): 7.90 (s, 1H), 7.48 (d, J=7.5 Hz, 2H), 7.37 (d, J=7.5 Hz, 2H), 7.12 (s, 1H), 6.55 (bs, 2H), 6.08 (s, 1H), 5.50 (bs, 1H), 5.10 (s, 2H), 2.08 (s, 3H). EXAMPLE 14 5-(4-acetoxymethylbenzoyl)-3-thiophene sulfonamide 0.20 g (0.6 mmol) of 5-(4-acetoxymethylbenzhydrol)-3-thiophene sulfonamide was added to 6 mL of acetone. 0.22 mL (0.6 mmol) of a 2.67M TBAF solution was added. After stirring at rt for 15 min the reaction was quenched with isopropyl alcohol. The mixture was diluted with water and extracted with ethyl acetate. The organic phase was washed with water (3×) followed with brine. The solution was dried over MgSO 4 and the solvent removed under vacuum. Recrystallization from ethyl acetate/hexane afforded 0.17 g of 5-(4-acetoxymethylbenzoyl)-3-thiophene sulfonamide as white crystals. 1 H NMR (acetone-d 6 ): 8.47 (d, J=1.4 Hz, 1H), 7.93 (s, 1H), 7.92 (d, J=8.3 Hz, 2H), 7.62 (d, J=8.3 Hz, 2H, 6.80 (bs, 2H), 5.22 (s, 2H), 2.10 (s, 3H). EXAMPLE 15 5-(4-hydroxymethylbenzoyl)-3-thiophene sulfonamide 14 mg (41.3 mmol) of 5-(4-acetoxymethylbenzoyl)-3-thiophene sulfonamide and 9 mg (61.8 mmol) of K 2 CO 3 were added to 3 mL of methanol. After stirring at rt for 11 h the solution was diluted with ethyl acetate and washed with 1N HCl followed with water (2×) and brine. The solvent was removed under vacuum to afford 12.5 mg of 5-(4-hydroxymethylbenzoyl)-3-thiophene sulfonamide as a white solid. 1 H NMR(acetone-d 6 ): 8.46 (d, J=1.4 Hz, 1H), 7.93 (d, J=1.4 Hz, 1H), 7.89 (d, J=8.3 Hz, 2H), 7.59 (d, J=7.9 Hz, 2H), 6.79 (bs, 2H), 4.77 (d, J=5.4 Hz, 2H), 4.51 (t, J=5.7 Hz, 1H). EXAMPLE 16 5-(4-formylbenzoyl)-3-thiophene sulfonamide 30 mg (0.1 mmol) of 5-(4-hydroxymethylbenzoyl)-3-thiophene sulfonamide and 300 mg of MnO2 were added to 5 mL of THF. After stirring at rt for 30 min the mixture was filtered through a bed of celite and eluted with ethyl acetate. The filtrate was concentrated and the crude product subjected to flash chromatography utilizing 1:1 ethyl acetate/hexane as the eluent to recover 16 mg of 5-(4-formylbenzoyl)-3-thiophene sulfonamide as a yellow solid. 1 H NMR(acetone-d 6 ): 10.21 (s, 1H), 8.52 (d, J=1.3 Hz, 1H), 8.12 (q, J=9.7 Hz, 4H), 7.94 (d, J=1.3 Hz, 1H), 6.79 (bs, 2H). EXAMPLE 16(a) 5-(3-formylbenzoyl)-3-thiophene sulfonamide 1 H NMR(acetone-d6): 10.18 (s, 1H), 8.52 (d, J=1.3 Hz, 1H), 8.14 (s, 1H), 8.23 (d, t, J=1.4, 8.0 Hz, 2H), 7.97 (d, J=1.4 Hz, 1H), 7.85 (t, J=8.0 Hz, 1H), 6.80 (bs, 2H). EXAMPLE 17 5-(4-formylbenzhydrol)-3-thiophene sulfonamide 0.12 g (0.32 mmol) of the product from Example #12, 4A molecular sieves and 56 mg (0.48 mmol) of NMO were added to 6 mL of dichloromethane. After stirring at rt for 15 min 5.6 mg (0.016 mmol) of TPAP was added. After 4 h at rt the mixture was filtered through a plug of celite and eluted with ethyl acetate. The filtrate was concentrated and the crude product subjected to flash chromatography utilizing 1:1 ethyl acetate/hexane as eluant to recover 42 mg of the desired product and 41 mg of starting material. 63 mg (0.17 mmol) of the product and a catalytic amount of TsOH were added to 5 mL of methanol. After 4 h at rt the solution was diluted with ethyl acetate and washed with saturated NaHCO 3 followed with water (3×) and brine. The solution was dried over MgSO 4 and the solvent removed under vacuum to afford 47 mg of 5-(4-formylbenzhydrol)-3-thiophene sulfonamide as a clear colorless oil. 1 H NMR(acetone-d 6 ): 10.04 (s, 1H), 7.94 (d, J=8.3 Hz, 2H), 7.93 (s, 1H), 7.73 (d, J=8.3 Hz, 2H), 7.18 (s, 1H), 6.58 (bs, 2H), 6.20 (d, J=4 Hz, 1H), 5.77 (d, J=4 Hz, 1H). EXAMPLE 18 5-[(methoxy)(3-trifluoromethylphenyl)methyl]-3-thiophene sulfonamide 0.20 g (0.6 mmol) of 5-(3-trifluoromethylbenzhydrol)-3-thiophene sulfonamide and 0.11 g (0.6 mmol) of TsOH were added to 10 mL of methanol. The solution was heated at reflux for 12 h. The solvent was removed under vacuum and the crude product subjected to flash chromatography utilizing 2:1 hexane/ethyl acetate as the eluant to recover 0.16 g of 5-[(methoxy)(3-trifluoromethylphenyl)methyl]-3-thiophene sulfonamide as a white solid. 1 H NMR (acetone-d 6 ): 7.99 (d, J=1.5 Hz, 1H), 7.66-7.80 (m, 4H), 7.23-7.24 (m, 1H), 6.59 (bs, 2H), 5.76 (s, 1H), 3.41 (s, 3H). EXAMPLE 18(a) 5-[(methoxy)(4-hydroxymethylphenyl)]methyl-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 7.94 (d, J=1.1 Hz, 1H), 7.39 (s, 4H), 7.08 (d, J=1.1 Hz, 1H), 6.56 (bs, 2H), 5.56 (s, 1H), 4.64 (d, J=5.9 Hz, 2H), 4.24 (t, J=5.9 Hz, 1H), 3.35 (s, 3H). EXAMPLE 19 5-(1-pentanoyl)-3-thiophene sulfonamide, oxime 0.10 gms (0.4 mmol) of 5-(1-pentanoyl)-3-thiophene sulfonamide and 0.28 gms (4 mmol) of NH 2 OH.HCl were dissolved in 5 ml of pyridine. The reaction vessel was sealed and heated at 60° C. overnight. The reaction solution was cooled to room temperature, diluted with ethyl acetate, washed three times with water and finally with brine. The organic phase was separated, dried over MgSO 4 , filtered and concentrated. Thin liquid chromatography showed that the starting compounds were present. The concentrate was redissolved in 5 ml of pyridine, 0.25 gms of NH 2 OH.HCl were added and the reaction vessel was sealed and heated at 60° C. overnight. The resulting reaction solution was cooled to room temperature, extracted with ethyl acetate, washed with water and brine as described above. After drying with MgSO 4 and filtering, the organic phase was concentrated and subjected to flash chromatography, utilizing a 2 to 1 mixture of hexane and ethyl acetate, as the eluant, to yield 78 mgs. of a white solid having the following NMR spectra: 1 H NMR (acetone-d 6 ): mixture of Isomers: 11.11 (bs), 10.50 (bs), 8.16 (s), 7.92 (s), 7.78 (s), 7.55 (s), 6.64 (bs), 2.68-2.80 (m), 1.35-1.67 (m), 0.89-0.95 (m). EXAMPLES 19(a)-(b) The compounds of Examples 6(a) and (b) are converted into the corresponding oxime derivatives by the method of Example 19. EXAMPLE 19(a) 5-(4-methoxybenzoyl)-3-thiophene sulfonamide, oxime 1 H NMR (acetone-d 6 ): 11.55 (s), 10.58 (s), 8.22 (d, J=1.4 Hz), 7.96 (d, J=1.4 Hz), 7.40-7.47 (m), 7.00-7.07 (m), 6.61-6.64 (m), 3.87 (s), 3.86 (s). EXAMPLE 19(b) 5-benzoyl-3-thiophene sulfonamide, oxime 1 H NMR (acetone-d 6 ): mixture of Isomers: 11.69 (bs), 10.65 (bs), 8.24 (d, J=1.4 Hz), 7.98 (d, J=1.4 Hz), 7.37-7.59 (m), 7.02 (d, J=1.4 Hz), 6.58-6.64 (m). EXAMPLE 20 5-(4-ethoxycarbonylbenzoyl)-3-thiophene sulfonamide 0.1 g (0.32 mmol) of 5-(4-carboxylbenzoyl)-3-thiophene sulfonamide was added to 0.19 g (1.13 mmol) of N,N'-diisopropyl-O-ethyl isourea 1.6 mL of THF. Solution was heated at 50° C. for 2 h. An additional 0.19 g of the isourea was added and the reaction stirred at 50° C. for 48 h. The mixture was filtered through a plug of celite and the filtrate collected and concentrated. Flash chromatography (35% ethyl acetate/hexane) recovered 80 mg of 5-(4-ethoxycarbonylbenzoyl)-3-thiophene sulfonamide as a white color solid. 1 H NMR (acetone-d 6 ): 8.50 (d, J=1.4 Hz, 1H), 8.20 (d, J=8 Hz, 2H), 8.10 (d, J=8 Hz, 2H), 7.92 (d, J=1.4 Hz, 1H), 6.80 (bs, 2H), 4.40 (q, J=7 Hz, 2H), 1.39 (t, J=7 Hz, 3H). EXAMPLE 20(a) 5-(3-butoxycarbonylbenzoyl)-3-thiophene sulfonamide 8.50 (d, J=1.4 Hz, 1H), 8.43 (m, 1H), 8.25 (m, 1H), 8.12 (m 1H), 7.94 (d, J=1.4 Hz, 1H), 7.74 (m, 1H), 6.80 (bs, 2H), 1.60 (s, 9H). EXAMPLE 20(b) 5-(4-(2-N,N-dimethylamino-1-ethoxy)carbonylbenzoyl)-3-thiophene sulfonamide 1 H NMR (CD 3 OD): 8.47 (d, J=1.4 Hz, 1H), 8.29 (d, J=8.5 Hz, 2H), 8.00 (d, J=8.5 Hz, 2H), 7.89 (d, J=1.4 Hz, 1H), 4.73 (t, J=5 Hz, 2H), 3.65 (t, J=5 Hz, 2H), 3.03 (s, 6H). EXAMPLE 20(c) 5-(4-t-butoxycarbonylbenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.50 (d, J=1.4 Hz, 1H), 8.16 (d, J=8.5 Hz, 2H), 8.00 (d, J=8.5 Hz, 2H), 7.93 (d, J=1.4 Hz, 1H), 6.79 (bs, 2H), 1.61 (s, 9H). EXAMPLE 21 5-(4-acetoxybenzoyl)-3-thiophene sulfonamide 58 mg (0.20 mmol) of 5-(4-hydroxybenzoyl)-3-thiophene sulfonamide, 81 mL (1.0 mmol) of pyridine and 94 mL (1.0 mmol) of acetic anhydride were added to 4 mL of THF. The reaction was stirred at rt for 1 1/4 h and then diluted with ethyl acetate. The organic phase was washed with water (2×) followed with brine. The solution was dried over MgSO 4 and the solvent removed under vacuum. Flash chromatography utilizing 1:1 hexane/ethyl acetate as the eluant recovered 51 mg of 5-(4-acetoxybenzoyl)-3-thiophene sulfonamide as tan color crystals. 1 H NMR (acetone-d 6 ): 8.47 (d, J=1.3 Hz, 1H), 7.98 (d, J=8.6 Hz, 2H), 7.96 (d, J=1.3 Hz, 1H), 7.37 (d, J=8.6 Hz, 2H), 6.78 (bs, 2H), 2.32 (s, 3H). EXAMPLE 21(a) 5-(3-acetoxybenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.22 (d, J=1.3 Hz, 1H), 7.69 (d, J=1.3 Hz, 1H), 7.53 (d,d, J=7.8, 1.3 Hz, 1H), 7.37 (t, J=7.8 Hz, 1H), 7.39 (s, 1H), 7.18-7.22 (m, 1H), 6.50 (bs, 2H), 2.04 (s, 3H). EXAMPLE 22 5-(4-propionoxybenzoyl)-3-thiophene sulfonamide 0.10 g (0.35 mmol) of 5-(4-hydroxybenzoyl)-3-thiophene sulfonamide, 85 mL (1.05 mmol) of pyridine, 26 mL (0.35 mmol) of propionic acid and 70 mg (0.37 mmol) of EDCI were added to 3.5 mL of THF. The reaction was stirred at rt for 46 h. The solution was diluted with ethyl acetate and washed with water (3×) followed with brine. The solution was dried over MgSO4 and the solvent removed under vacuum. Flash chromatography utilizing 1:1 ethyl acetate/hexane recovered 77 mg of 5-(4-propionoxybenzoyl)-3-thiophene sulfonamide as a clear colorless oil. 1 H NMR (acetone-d 6 ): 8.47 (s, 1H), 7.99 (d, J=8.7 Hz, 2H), 7.95 (s, 1H), 6.79 (bs, 2H), 2.67 (q, J=7.4 Hz, 2H), 1.21 (t, J=7.4 Hz, 3H). EXAMPLE 22(a) 5-(3-benzoxybenzoyl)-3-thiophene sulfonamide 1 H NMR (acetone-d 6 ): 8.50 (d, J=1.4 Hz, 1H), 8.21 (d, J=7.2 Hz, 2H), 8.00 (d, J=1.4 Hz, 1H), 7.59-7.88 (m, 7H), 6.78 (bs, 2H). The compounds of the invention were assayed for biological activity as follows: Carbonic anhydrase activity was assayed according to the micromethod of Maren (J. Pharmacol. Exptl. Therap., 130, 26-29, 1960). All solutions and reagents were maintained at 0°-4° C. The final assay mixture contained 16 mM phenol red, added enzyme and 62.5 mM sodium carbonate/bicarbonate. Its volume was kept constant at 0.8 mL. The time required for the added enzyme to lower the pH of CO 2 -saturated carbonate/bicarbonate buffer from pH 9.9 to 6.8 was measured using the color change of phenol red as endpoint. T 1 is the time recorded for the reaction containing no enzyme. T 2 is the time recorded for the reaction containing pure CA11 enzyme from human erythrocyte, or an unknown amount in a sample. Enzyme activities (unit) were calculated using the formula: Unit/ug=(T.sub.1 -T.sub.2)/(T.sub.2 *ug protein used in assay) IC50 of a carbonic anhydrase inhibitor is the concentration that lowers the enzyme activity to half. The results of this assay are reported in Table 1, below. ______________________________________Structures IC50nM______________________________________5-(4-acetoxybenzoyl)-3-thiophene sulfonamide 12 nM5-(4-hydroxy-3-(N,N-dimethylaminomethyl) 30 nMbenzoyl)-3-thiophene sulfonamide5-(4-hydroxy-3,5-(bis-N,N-dimethylaminomethyl) 155 nMbenzoyl)-3-thiophene sulfonamide5-(hydroxymethylbenzoyl)-3-thiophene sulfonamide 17 nM5-(4-propionoxybenzoyl)-3-thiophene sulfonamide 9 nM5-(3-hydroxybenzoyl)-3-thiophene sulfonamide 6.7 nM5-(3-carboxybenzoyl)-3-thiophene sulfonamide 11, 14 nM5-(3-formylbenzoyl)-3-thiophene sulfonamide 7.3 nM5-(4-butylbenzoyl)-3-thiophene sulfonamide 8.7 nM5-(3-trifluoromethylbenzoyl)-3-thiophene sulfonamide 8.3 nM5-(2-N,N-dimethylamino-1-ethoxy)carbonylbenzoyl)- 25 nM3-thiophene sulfonamide5-(3-butoxycarbonylbenzoyl)-3-thiophene sulfonamide 25 nM5-(4-acetoxybenzoyl)-3-thiophene sulfonamide 3.6 nM[5-(3-sulfonamidothienyl)][2-pyridyl] ketone 19 nM5-(4-ethoxycarbonylbenzoyl)-3-thiophene sulfonamide 6 nM5-(4-t-butoxycarbonylbenzoyl)-3-thiophene 3 nMsulfonamide5-(3-benzoxybenzoyl)-3-thiophene sulfonamide 5.3 nM5-(4-formylbenzoyl)-3-thiophene sulfonamide 13 nM5-benzoyl-3-thiophene sulfonamide 13 nM5-(4-methoxybenzoyl]-3-thiophene sulfonamide 26 nM5-(1-heptanoyl)-3-thiophene sulfonamide 14 nM5-(1-pentanoyl)-3-thiophene sulfonamide 27 nM5-(4-carboxybenzoyl)-3-thiophene sulfonamide 3.4, 5 nM5-(4-hydroxybenzoyl)-3-thiophene sulfonamide 17 nM5-(4-acetoxymethylbenzoyl)-3-thiophene sulfonamide 6 nM5-(2-fluorobenzoyl)-3-thiophene sulfonamide 18 nM5-(3-fluorobenzoyl)-3-thiophene sulfonamide 12 nM5-(3,5-difluorobenzoyl)-3-thiophene sulfonamide 15 nM5-(1-hydroxypentyl)-3-thiophene sulfonamide 32 nM5-(4-hydroxymethylbenzhydrol)-3-thiophene 41 nMsulfonamide5-(4-formylbenzhydrol)-3-thiophene sulfonamide 18 nM5-(1-hydroxyheptanyl)-3-thiophene sulfonamide 31 nM5-(4-methoxybenzhydrol)-3-thiophene sulfonamide 16 nM5-benzhydrol-3-thiophene sulfonamide 74 nM5-(4-acetoxymethylbenzhydrol)-3-thiophene 21 nMsulfonamide5-(4-hydroxybenzhydrol)-3-thiophene sulfonamide 26 nM5-(3-hydroxybenzhydrol)-3-thiophene sulfonamide 37 nM5-[(hydroxy)(pyridyl)methyl]-3-thiophene 240 nMsulfonamide5-(acetoxyphenylmethyl)-3-thiophene sulfonamide 90 nM5-(4-methoxybenzoyl)-3-thiophene sulfonamide, oxime 31 nM5-heptyl-3-thiophene sulfonamide 21 nM5-(1-pentanoyl)-3-thiophene sulfonamide, oxime 22 nM5-[(methoxy)(4-hydroxymethylphenyl)]methyl- 13 nM3-thiophene sulfonamide5-[(methoxy)(3-trifluoromethylphenyl)methyl]- 18 nM3-thiophene sulfonamide5-benzoyl-3-thiophene sulfonamide, oxime 53 nM______________________________________ While particular embodiments of the invention have been described it will be understood of course that the invention is not limited thereto since many obvious modifications can be made and it is intended to include within this invention any such modifications as will fall within the scope of the appended claims.

The present invention provides novel carbonic anhyrase inhibitors represented by the structural formula: ##STR1## wherein R 1 and R 2 are, for example, independently (a) hydrogen; or (b) OR 4 , wherein R 4 is hydrogen or C 1-7 alkyl; or (c) NR 5 R 6 , wherein R 5 and R 6 are independently hydrogen, or C 1-7 alkyl, or C 1-7 alkyl substituted with one or more halogen or OR 4 ; or (d) --COR 7 , wherein R 7 is hydrogen, C 1-7 alkyl, or NR 5 R 6 ; or (e) --SR 8 , wherein R 8 is hydrogen or C 1-7 alkyl, or C 1-7 alkyl substituted with one or more halogen, or OR 4 ; or (f) C 1-7 alkyl, or C 1-7 alkyl substituted with one or more halogen, or OR 4 or NR 5 R 6 ; or (g) R 1 and R 2 are together (i) ═O, or (ii) ═NOR 8 or (iii) ═S; and R 3 is (h) C 1-7 alkyl or C 1-7 substituted with one or more halogen, OR 4 or NR 5 R 6 .

This is a division, of application Ser. No. 749,589, filed June 27, 1985, now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to integrated circuits and in particular to integrated circuits in complementary circuit technology comprising at least two MIS field effect transistors of different channel types wherein the first is mounted in a doped semiconductor body of a first conductivity type and the second is mounted in a tub-shaped semiconductor body of a second conductivity type mounted in the semiconductor body. 2. Description of the Prior Art In integrated circuits of the complementary circuit technology wherein two field effect transistors of different channel types with the first one mounted in a doped semiconductor body of a first conductivity type and the second mounted in a tub-shaped semiconductor body of a second conductivity type and wherein the semiconductor body 2 of the second conductivity type is electrically connected to a supply voltage and the first field effect transistor is provided with a source terminal which lies at a reference potential there is a difficulty in that four successive semiconductor layers of alternating conductivity type are generally present between a terminal of a field effect transistor of the first channel type which is mounted in the tub-shaped semiconductor region and a terminal of a field effect transistor of the second channel type which is mounted outside of this zone such that the one connecting region of the first transistor forms the first semiconductor layer and the tub-shaped semiconductor region forms the second with the semiconductor body forming the third and the one connecting region of the second transistor forming the first semiconductor layer. When an overvoltage which exceeds the supply voltage by a specific amount, as for example 500 mV, occurs on the mentioned terminal of the transistor of the first channel type, the pn-junction between the first and second semiconductor layers can be positively biased to a degree such that a current path occcurs between the transistor terminals and this current path is attributable to a parasitic thyristor effect (latchup) within the four layer structure. This current path will also remain in effect after the decay of the overvoltage and can thermally overload the integrated circuit. SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the disadvantages of the prior art described above. A feature of the invention is to provide a metal contact at the surface of a semiconductor region inserted into the semiconductor body and doped oppositely thereto with the metal contact forming a Schottky diode together with the semiconductor region and the metal contact is connected to a connecting region of the second field effect transistor whereas the semiconductor region is electrically connected to the supply voltage V DD . The advantages obtainable with the invention lie particularly in that the parasitic thyristor effect is avoided by means of a simple structure which particularly during manufacture of the circuit does not require any additional method steps but only slight modifications of the prior art steps: Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure and in which: BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exemplary embodiment of the invention; FIG. 2 is a circuit diagram of the exemplary embodiment of FIG. 1; FIG. 3 is a modified form of the invention; FIG. 4 is another embodiment of the invention; and FIGS. 5, 6 and 7 illustrate various steps in the method of manufacturing the embodiment of FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENTS As illustrated in FIG. 1 an integrated circuit comprises a body 1 of doped semiconductor material, as for example, p-conductivity type silicon. The semiconductor body 1 contains a n-conductive tub-shaped conductor region 2 which extends up to the boundary layer 1a of the body 1. Mounted at the boundary surface 1a are field insulated regions 3a, 3b, 3c, 3d, and 3e which may be made of, for example, SiO 2 and between these insulation regions 3a through 3e, respective gate insulation regions which cover the active regions of the semiconductor circuit are mounted. There is provided in a first active region which is mounted in the lateral boundaries of the semiconductor region 2 a small p+ doped region 4 and a p+ doped region 5 which respectively form the source and drain regions of p- channel type field effect transistor T1. The channel region lying between regions 4 and 5 is covered by gate 6 which is provided with a terminal E and is separated from the boundary surface 1a by a thin gate insulation layer 7 of, for example, SiO 2 . A conductive coating 9 is applied to an intermediate insulation layer 8 which covers the gate 6 and it contacts the source region 4 through a window 10 formed in insulation layer 8 and is provided with a terminal 11. The terminal 11 is therefore is electrically connected to a supply voltage V DD . Another conductive coating 12 is connected to the intermediate insulation layer 8 and contacts the drain region 5 in the area of a window 13 and is electrically connected to a terminal A. An n-channel field effect transistor T2 is mounted in an active region lying between the insulation regions 3d and 3e and field effect transistor T2 is formed with n+ doped regions 14 and 15 which are formed in the body 1 as shown. A gate region 16 lies between the regions 14 and 15 and is separated by gate insulation layer 17. The gate 16 is connected to terminal E. A conductive coating 18 which contacts the drain region 15 through a window 19 of the intermediate insulating layer 8 is connected to terminal A and a conductive coating 20 which contacts the source region 14 through a window 21 is connected to a terminal 22 to which is applied a reference potential V SS . An n+ doped connecting region 23 is inserted into the semiconductor region 2 and this region 23 is contacted in the region of a window 24a by a conductive coating 24 mounted above the intermediate insulation layer 8 and the conductive coating 24 is connected to terminal 11. In the region of an additional window 25 of the intermediate insulation layer 8 a part of the conductive coating 12 forms a metal contact on the surface of the n-conductive semiconductor region 2 and this metal contact comprises a Schottky diode together with semiconductor region 2. Assuming an n-doping concentration about 10 16 cm -3 in the semiconductor region 2, the conductive coating 12 is expediently composed of aluminum. It is also advantageous if the conductive coating 12 is composed of tantalum silicide (TaSi 2 ) or it can be designed as a double layer which comprises a first layer of TaSi 2 and a second layer of aluminum which overlies the first layer. Other materials which are employed in a known fashion for Schottky diodes such as, for example, platinum or molybdenum may also be used for the conductive coating 12. Aluminum or the double layer of TaSi 2 and Al, however, have the advantage that they can also be employed for the coatings 9, 18, 20 and 24 such that all of the coatings on the intermediate insulation layer 8 can be applied in a single process step. It is essential that the leading threshold voltage V D of the Schottky diode D be lower than the leading threshold voltage of the pn-junction between the semiconductor region 5 and the semiconductor region 2 and this is referenced as V pn . As is illustrated in FIG. 2 the p-channel transistor T1 and n-channel transistor T2 are series connected with their source and drains connected to the supply voltage V DD which is supplied via 11 and 22 and their gates are electrically connected to the common terminal E. The Schottky diode D which is composed of parts 12 and 2 is inserted between terminals A and 11. In case a voltage which exceeds the supply voltage V DD by amount that is equal to or greater than the leading threshold voltage V D of the Schottky diode D appears at the inverter output A during operation, then D becomes conductive and limits the voltage V A to the value V A =V DD +V D . Thus, it is avoided that V A continues to increase and reaches or exceeds a value V A =V DD +V pn which causes parasitic thyristor effects to occur in the region of the four layer structures 5, 2, 1 and 14 with such thyristor effects potentially leading to the formation of a current path between terminals A and 22 and to a thermal overload of the entire structure. FIG. 3 illustrates a modification of the exemplary embodiment of FIG. 1 and differs from FIG. 1 in that the windows 13 and 25 are combined to a single window 13' and the conductive coating 12 which is designated by 12' in FIG. 3 contacts both the drain region 5' of T1 as well as the semiconductor region 2 in the area of this window. Since the drain region 5' is significantly higher doped than the semiconductor region 2, the coating 12' forms an ohmic contact on 5' and forms the Schottky diode D with the semiconductor zone 2. Another embodiment of the invention is illustrated in FIG. 4 wherein the Schottky diode D is arranged differently than in FIG. 1 and it lies in its own n-conductive semiconductor region 2' which is inserted into the semiconductor body next to the n-conductive semiconductor region 2. The region 2' has approximately the same doping concentration as region 2. The field insulation region 3b and 3c of FIG. 1 are combined into a single field insulation region 3b' and the coating 12" which replaces the coating 12 of FIG. 1 contacts only the drain region 5 of transistor T1. The field insulation regions 3d is divided into two regions 3d' and 3d" and the semiconductor region 2' is mounted therebetween. An n+ doped connecting region 26 is inserted into the semiconductor region 2' and this is contacted by conductive coating 27 in the area of a window 28 of the intermediate insulation layer 8. The coating 27 is connected to terminal 11. A conductive coating 29 which is composed of the same material as the coating 12 illustrated in FIG. 1 forms a metal contact in the area of a window 30 of the intermediate insulation layer 8 on the semiconductor region 2' and this metal contact comprises the Schottky diode D together with semiconductor region 2'. The coating 29 is connected to terminal A. In FIGS. 3 and 4, those parts which were described with reference to FIG. 1 are provided with the same reference characters as in FIG. 1. The modifications of FIGS. 3 and 4 operate in the same manner as that described for FIG. 1 and the electrical schematic of FIG. 2. In order to manufacture the circuit according to FIG. 1 an n-doped tub-shaped semiconductor region 2 which, for example, has a doping concentration of 10 16 cm -3 is inserted by means of a diffusion process into a body 1 of p-conductive silicon which has a basic doping concentration of about 10 15 cm -3 . Subsequently, a thin Si 3 N 4 layer is applied to the boundary surface 1a and such Si 3 N 4 layer being structured such by means of a photolithographic step that it remains only on the active semiconductive regions. Field oxidation regions 3a through 3e of SiO 2 are formed by means of thermal oxidation at those locations on the body 1 that are not covered by the Si 3 N 4 layer. After removal of the Si 3 N 4 layer portions, gate oxide layers S1 through S4 are grown on the active regions of the semiconductor body 1 by thermal oxidation process and these gate oxide layers form the previously mentioned gate oxide regions. The gates 6 and 16 of the field effect transistor T1 and T2 are then formed on the gate oxide layers S1 and S4 by using photolithographic steps and are formed therefrom with a polycrystalline silicon layer that has been applied on the surface. As is illustrated in FIG. 5 the n+ doped regions 14 and 15 of transistor T2 and the connecting region 23 are generated by means of ion implantation which is indicated by the arrows Im1. The lefthand part of the semiconductor body 1 extending up to the middle of the thick film region 3c is covered with a photoresist layer L1 during this time. Then the photoresist layer L1 is removed and as shown in FIG. 6, a further photoresist layer L2 is applied which covers the righthand portion of the body 1 up to the middle of the thick film region 3b whereby p+doped region 4 and 5 of transistor T1 are formed by means of ion implantation which is indicated by arrows Im2. As is illustrated in FIG. 7, an intermediate insulation layer of SiO 2 is applied using a deposition technique in a following method step and this layer 8 is provided with windows 10, 13, 21, 19, 24a and 25 above the regions 4, 5, 14 and 15 as well as above the connecting region 23 and between the field insulation regions 3b and 3c. These windows are etched through to the boundary layer 1a so that the gate insulation layers S1 through S4 indicated in FIG. 6 are also opened. For reasons of a simplified illustration the gate insulation layers S1 and S4 are not separately illustrated but are provided with the reference characters 7 and 17 since they lie under the gates 6 and 16. The remaining parts of S1 and S4 as well as the layers S2 and S3 are incorporated into the intermediate insulation layer 8 and are shown together with the insulation layer 8 as a uniform insulation layer. The conductive coatings 9, 12, 24, 18 and 20 are subsequently applied with this preferably occurring by means of a corresponding structuring of a surface wide coating by means of photolithographic steps. The coatings 9 and 24 finally are provided with the terminal 11 and the coating 20 is provided with the terminal 22 and the gates 6 and 16 are provided with the terminal E. The coatings 12 and 18 are provided with a terminal A. Other embodiments of the invention differ from those described in that the individual semiconductor parts are replaced by those of the respectively opposite conductivity types whereby the voltage of the opposite polarity can then be applied. In addition to these embodiments, the inventive concept also encompasses other integrated circuits in complementary circuit technology wherein at least two field effect transistors having different channel types are integrated in a semiconductor body such that at least one of them belongs to a first channel type and lies in a tub-shaped zone which is of a conductivity type opposite to that of the semiconductor body and where as least one other field effect transistor has a second channel type and is mounted in the semiconductor body outside of this zone. The tub-shaped zone is thereby always electrically connected to a supply voltage. The parasitic thyristor effect which was described under the Prior Art with reference to the transistors T1 and T2 which can occur in any circuit of this type is suppressed by the insertion of a Schottky diode between a connecting region of the field effect transistor lying in the tub-shaped zone and the terminal of the supply voltage when the leading threshold voltage V D of the Schottky diode is selected to be lower than the leading threshold voltage of the pn-junction between this connecting region in the tub-shaped zone. Although the invention has been described with respect to preferred embodiments, it is not to be so limited as changes and modifications can be made which are within the full intended scope of the invention as defined by the appended claims.

An integrated circuit in complementary circuit technology comprising two field effect transistors (T1, T2) of different channel types with the first one (T2) mounted in a doped semiconductor body (1) having a first conductivity type and the other FET (T1) mounted in a semiconductor zone 2 of a second conductivity type which is arranged in said body. The object is to provide a protection against thermal overloads which can appear due to "latch up" influences when overvoltages at the one connecting region of the field effect transistor (T1) mounted in the semiconductor zone occur. This is accomplished by the mounting of a metal contact (12) on the surface of a semiconductor region (2') inserted into the semiconductor body 1 and doped oppositely thereto with such metal contact forming a Schottky diode (D) with the semiconductor region (2') which can be connected to the connecting region of the field effect transistor T1 mounted in the semiconductor region 2 whereas the semiconductor region (2') is electrically connected to the supply voltage (V DD ). The circuits are applied in CMOS circuits.

[0001] This application is a divisional of application Ser. No. 10/226,190, filed on Aug. 23, 2002, which is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION [0002] The present invention relates to image sensors which use a stacked avalanche multiplication layer to amplify the intensity of light captured by a pixel circuit. BACKGROUND OF THE INVENTION [0003] Amid the rising popularity for digital image devices such as digital cameras is a demand for increasingly higher picture resolution and for increasingly compact designs of such devices. Due to the interior space constraints in the housings of the compact designs, it is necessary to reduce the sizes of the electronic circuits in the device, including the image sensor. However, upon shrinking the size of the image sensor, a tradeoff must be made between resolution and the signal levels outputted from the image sensor. If the resolution is kept the same upon reducing the size of the image sensor, the size of each pixel must be proportionately reduced. Smaller pixels reduce the amount of charge that can be collected by each pixel during image exposure, which in turn reduces the sensitivity of the image sensor. Although the reduced sensitivity effect can be offset by increasing the integration (exposure) time, this is an undesirable “solution” because increasing integration time also increases the potential for obtaining a blurred image if there is any movement by the image subject or the device during exposure. On the other hand, in order to maintain the same sensitivity without having to increase integration time, the pixels must be made larger, which limits the resolution. [0004] One solution towards achieving both a more compact size and high image quality is disclosed in “CMOS Image Sensor Overlaid with a HARP Photoconversion Layer,” by T. Watabe, et al., published in the Program of the 1999 IEEE Workshop on (Charge-Coupled Devices and Advanced Image Sensors, pp. 211-214. In this image sensor, which is shown in FIGS. 1A and 1B , the pixel circuit 902 is overlaid with a stacked charge multiplying photoconversion layer, such as a high-gain avalanche rushing amorphous photoconductor (“HARP”) photo-conversion layer 904 for amplifying the fight signal produced by each pixel. [0005] When a photon 906 hits the upper surface 908 of the HARP layer 904 , a charge 910 in the form of holes is generated and amplified to many times its original level while being propelled through the HARP layer 904 to the bottom side 912 . The pixel circuit 902 is electrically connected to the bottom side 912 of the HARP layer 904 such that the amplified light signal 910 , upon reaching the bottom side 912 of HARP layer 904 , is conducted into the pixel circuit 902 as electrical charge. The charge accumulates at a storage node 914 in the pixel circuit until the pixel data is read out by activating the gate of a row select switch 916 . The amount of charge accumulated at the node 914 , which is proportional to the intensity of light 906 detected, is read out. In this manner, the image sensor of FIGS. 1A and 1B allows each pixel to capture image data with an intensity and sensitivity equivalent to that attainable by significantly larger pixels which do not have the avalanche multiplication capability. As a result, use of a HARP layer enables the image quality to be improved without having to increase the size of the image sensor array. [0006] In order to obtain avalanche multiplication in the HARP layer, an electric field of about 10 6 V/cm is required, which is achieved by applying an operating voltage of between 50-100 V to the HARP layer. In a typical HARP image sensor, voltages of less than about 8 V are used in the pixel circuit connected beneath the HARP layer, with the pixel circuit generally having a breakdown voltage of around 20 V. When the intensity of the incident light on the image sensor is at the upper end of the detection range for the charge multiplying photoconversion layer, the voltage level accumulating at the storage diode beneath the HARP layer approaches the level of the operating voltage applied to the HARP layer. Thus, voltages of 50-100 V may be applied to the storage diode when the image sensor is exposed to a strong light, resulting in a breakdown of the readout components of the pixel circuit. [0007] To address this problem, attempts have been made to build a pixel circuit having a higher breakdown tolerance. An example of such a high tolerance pixel circuit is disclosed in the article by T. Watabe et al. mentioned above, in which the pixel circuit is constructed as MOS transistor having a double drain structure. This structure is shown in FIG. 2 , in which the n-doped drain formed in the p-doped silicon layer 922 includes a low-dose n− region 924 surrounding a conventional high-dose n+ region 926 . The double drain MOS transistor structure was shown to achieve an endurance voltage up to just under 60 V. However, a special MOS fabrication process is required for forming the double drain MOS transistor, and the size of the MOS transistor makes it difficult to attain small pixel sizes for high resolution image sensors. BRIEF SUMMARY OF THE INVENTION [0008] The present invention mitigates problems of the high voltages which may be generated by a HARP layer under bright light conditions by incorporating a protection circuit into the pixel circuit connected to the HARP layer. The protection circuit prevents the pixel circuit from breaking down when the voltage in the pixel circuit reaches the operating voltage applied to the charge multiplying photoconversion layer in response to the image sensor being exposed to a strong light. In particular, the protection circuit of the present invention may be designed in any of several configurations in which additional voltage entering the pixel circuit from the charge multiplying photoconversion layer over a predetermined threshold voltage level is dissipated before reaching the storage node and other lower voltage components downstream therefrom. [0009] These and other features and advantages of the present invention will become more apparent from the following detailed description of the invention which is provided with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1A is a cross-sectional view of a pixel in an image sensor having a charge multiplying photoconversion layer as known in the art; [0011] FIG. 1B is a circuit diagram of the pixel arrangement shown in FIG. 1A ; [0012] FIG. 2 is a cross-sectional view of a double-drain MOS transistor as known in the art; [0013] FIG. 3 is a circuit diagram of a first preferred embodiment in accordance with the present invention; [0014] FIG. 4 is a circuit diagram of a second preferred embodiment in accordance with the present invention; [0015] FIG. 5 is a circuit diagram of a third preferred embodiment in accordance with die present invention; [0016] FIG. 6 is a circuit diagram of a fourth preferred embodiment in accordance with the present invention; [0017] FIG. 7 is a relevant portion of a circuit diagram in accordance with a fifth embodiment of the present invention; [0018] FIG. 8 is a relevant portion of a circuit diagram in accordance with a sixth embodiment of the present invention; [0019] FIG. 9 is a relevant portion of a circuit diagram in accordance with a seventh embodiment of the present invention; [0020] FIG. 10 is an example of an imaging apparatus incorporating the present invention, and [0021] FIG. 11 is an illustration of a processing system communicating with the imaging apparatus of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0022] A first preferred embodiment of the present invention is shown in FIG. 3 , and is similar to the pixel arrangement shown in FIG. 1B in that it includes a charge (hole) multiplying photoconversion layer 102 connected to a voltage V target at its upper plate and connected to storage node 104 of a storage element 510 at its bottom plate. In this embodiment, storage element 510 is provided as a storage diode 106 . Although the charge multiplying photoconversion layer is preferably a high-gain avalanche rushing amorphous photoconductor (HARP) photoconversion layer, other structures for detecting and performing photoconversion of a light signal and subsequently or simultaneously amplifying the resulting electrical charge may be used. Storage node 104 is the cathode of storage diode 106 for accumulating charge corresponding to image data being collected during the image sensor integration time. An output circuit 500 is connected to and positioned downstream from node 104 , for reading out the charge accumulated at storage diode 106 . As shown in FIG. 3 , output circuit 500 may be simply constructed as a row select transistor 108 . [0023] The anode of storage diode 106 is connected to ground so as to block current flow through diode 106 when the voltage at node 104 is a higher level than the ground connection, which will always be the case when an image signal is received from the charge multiplying photoconversion layer 102 , since the signal charges are holes. Thus, with respect to storage diode 106 , therefore, as long as the row select transistor 108 is open, charge flowing from charge multiplying photoconversion layer 102 as a result of the detection of light will accumulate at node 104 . [0024] Row select transistor 108 of output circuit 500 is connected to a column readout line 110 so that when the gate for the row select transistor 108 is closed, the charge at storage node 104 is transferred to the column readout line 110 . When the column line containing the relevant pixel is activated, the image data from the pixel is transferred out of the pixel circuit 100 into an image processor where that charge is translated into image data along with the data read out from the other pixels in the image sensor array, to thereby construct the output image. [0025] In order to prevent the charge accumulating at node 104 from reaching the breakdown point of storage diode 106 or row select transistor 108 , a protection circuit 520 comprising a protection diode 112 , the anode of which is connected to node 104 of storage diode 106 . The cathode of protection diode 112 is connected to a voltage V dd , so that lichen the voltage level at storage node 104 reaches the level of V dd , any additional voltage arriving from the charge multiplying photoconversion layer 102 is bled off away from node 104 toward the voltage source V dd . In this manner, protection diode 112 selves to limit the voltage at node 104 to V dd . [0026] Once voltage is bled off from node 104 through protection diode 112 , image data representing light intensities detected at the upper end of the capability range of charge multiplying photoconversion layer 102 will be lost. Thus, the voltage level at source V dd should be set to strike a balance between minimizing the potential to lose image data acquired in the upper end of the detection range of layer 102 , and limiting the voltage at node 104 to a comfortable level to avoid the risk of breakdown of the storage diode 106 and the row select transistor 108 . [0027] A second preferred embodiment of the present invention is shown in FIG. 4 , and is identical to the pixel circuit of the first embodiment except that the storage element 510 is embodied as a storage capacitor 202 instead of a storage diode. Preferably, storage capacitor 202 has a large capacitance value per unit area, even more preferably in the range of 2-5 fF/μ 2 . Such a capacitor provides a higher capacitance value while reducing the space required for the charge storage region, relative to the use of a storage diode. [0028] In this embodiment, charge from the charge multiplying photoconversion layer 204 is stored in the capacitor 202 , until the voltage at the capacitor 206 reaches V dd . Additional voltage flowing to node 206 from the charge multiplying photoconversion layer 204 is then directed through the protection diode 208 of protection circuit 520 so that the charge stored in the capacitor 202 maintains a voltage of around V dd . [0029] A third preferred embodiment of the present invention, as shown in FIG. 5 , is identical to the pixel circuit of the first embodiment, except that the protection diode of the protection circuit 520 is replaced with an n-MOS transistor 302 . Both the drain and the gate of the transistor 302 are connected to the storage diode 308 of storage element 510 , aid the source of the transistor 302 is connected to a voltage potential of V dd . [0030] As in the embodiments described previously, charge from the image signal accumulates at the storage node 304 until the voltage at node 304 reaches and surpasses V dd . Once this occurs, the higher voltage at the transistor drain causes the excess voltage to flow through the transistor, so that the voltage at the storage node 304 remains around V dd . [0031] In a variant of this embodiment, the storage diode 308 of storage element 510 may be replaced with the high capacity capacitor as described above with reference to the embodiment of FIG. 4 . [0032] FIG. 6 shows a fourth preferred embodiment of the present invention, which is identical to the embodiment of FIG. 3 except that the protection circuit 520 further includes a resistor 402 positioned between the bottom plate 406 of the charge multiplying photoconversion layer 404 and the storage diode 408 of storage element 510 . The resistor preferably has a high resistance value which reduces the voltage passing through the pixel circuit 400 from the charge multiplying photoconversion layer 404 and the storage diode 408 at node 410 . [0033] The presence of protection circuit 520 , embodied here as protection diode 412 , provides additional protection for the pixel circuit 400 , so that in the event the signal voltage flowing from the charge multiplying photoconversion layer 404 is significantly larger than V dd that the voltage at node 410 upon passing through resistor 402 is still too high, the excess voltage will be directed away from the storage diode 408 and the row select transistor 414 through the protection diode 412 . [0034] A first variation of the FIG. 6 embodiment may be provided by replacing the storage diode 408 of storage element 510 with the capacitor discussed above in the embodiment of FIG. 4 . Similarly, the present invention also encompasses a second variation of this embodiment in which the protection diode 412 is replaced with an n-MOS transistor as described above in the embodiment of FIG. 5 . In a third variation of the FIG. 6 embodiment, both the storage diode 408 of storage element 510 and the protection diode 412 are replaced with the capacitor of FIG. 4 and the n-MOS transistor of FIG. 5 , respectively. [0035] In an image sensor using a charge multiplying photoconversion layer, as the voltage level at the storage node rises, the effective voltage applied to the photoconversion layer decreases, which affects the charge amplification function of the photoconversion layer. For example, if the voltage V target applied to the charge multiplying photoconversion layer is reduced, the amplification achieved by the photoconversion layer is also reduced. Thus, when the signal level is read out upon activating the row select switch, the signal level recorded by the imaging device will be less than the signal level actually detected. [0036] The fifth through seventh embodiments of the present invention, described below with reference to FIGS. 7-9 , address this concern. Each of the fifth through seventh embodiments is constructed by replacing the output circuit 500 in any of the embodiments shown in FIGS. 3-6 , with the respective circuit shown in FIGS. 7-9 . [0037] According to the fifth embodiment of the present invention, as shown in FIG. 7 , a differential amplifier 502 is connected to a constant voltage supply V ref at a positive input thereof, and the output is connected to a capacitor 504 in a feedback loop connecting to the negative input to the differential amplifier. A reset switch 506 is connected in parallel to the capacitor 504 between the negative input and the output of the differential amplifier 502 for shorting out the capacitor 504 . A row select switch 508 , which may be identical to the row select transistor 108 discussed above with reference to FIG. 3 , is also connected to the output of the differential amplifier downstream of the connection to the capacitor 504 . [0038] During the integration time in this embodiment, hole current from the charge (hole) amplifying photoconversion layer is inputted to the negative input of the differential amplifier, through the differential amplifier and through the feedback loop. In this manner, die hole current from the photoconversion layer is integrated on the feedback capacitor 504 . The output voltage of the differential amplifier is inversely linearly proportional to the intensity, of incident light on the photoconversion layer in that as the intensity, of light detected by the photoconversion layer increases, the output voltage from the differential amplifier decreases. When the row select switch 508 is closed, the output voltage of the differential amplifier 502 is read out. [0039] The differential amplifier 502 together with the feedback loop solves the problem of the decreasing amplification in the charge multiplying photoconversion layer by fixing the negative input voltage to the differential amplifier 502 at V ref , which in turn maintains the effective operating voltage V target of the charge multiplying photoconversion layer at a constant level. If no protection circuit 520 is provided as described above, when the intensity of light exceeds a normal operation level of the output circuit, the output voltage of the differential amplifier falls below its normal operation level, and the differential amplifier and the feedback loop lose the ability to function properly. In this case, the hole current begins to accumulate on a parasitic capacitor at the negative input to differential amplifier, and the voltage thereat begins rising towards the level of V target . [0040] The presence of the protection circuit 520 between the negative input to the differential amplifier 502 and the photoconversion layer in accordance with the present invention thus serves to prevent the output voltage of the differential amplifier falls below its normal operation level by diverting current from the photoconversion layer above the normal level and transferring the excess current through the protection circuit away from the differential amplifier. As described with respect to embodiments of FIGS. 3-6 above, the protection circuit 520 may be constructed as a protection diode, an n-MOS transistor, a resistor and a protection diode, or a resistor and an n-NMOS transistor. [0041] Since the intensity of light detected by the photoconversion layer is represented by the voltage of the output signal of the differential amplifier 502 and is integrated in the feedback loop during the integration time, the storage circuit 510 may be omitted in this embodiment, if desired. The presence or absence of the storage circuit 510 does not impact the operation of the pixel circuit, because the voltage at the negative input node of the differential amplifier 502 is fixed at V ref . In the event that the intensity of detected light exceeds the normal operation level of output circuit 500 , however, the presence of the storage circuit 510 serves as an accumulation point along the path between the photoconversion layer and the negative input of the differential amplifier from which the excess current can be bled off through the protection circuit 520 . [0042] The output circuit according to the sixth embodiment is shown in FIG. 8 , and is identical to the output circuit of FIG. 7 , except that the output circuit of FIG. 8 converts the hole current from the charge amplifying photoconversion layer into a logarithmic signal, to account for the decreasing amplification level of the charge multiplying photoconversion layer due to the inverse relationship between the voltage level at the storage node and the effective V target . In this regard, instead of a capacitor connected between the negative input and the output of the differential amplifier as shown in FIG. 7 , the output circuit of FIG. 8 provides a feedback diode 604 having its anode connected to the negative input of the differential amplifier 602 and its cathode connected to the output of the differential amplifier 602 . As configured in this manner, the output circuit of this embodiment thus logarithmically compresses the readout signal representing the intensity of the detected light. [0043] As shown in FIG. 9 , the output circuit of the seventh embodiment essentially combines the output circuits of FIGS. 7 and 8 , to thereby provide linear output signals in low light conditions and logarithmic output signals in brighter light conditions. Specifically, in this output circuit, a capacitor 704 is connected in parallel with a feedback diode 706 in a feedback loop connected between the output of the differential amplifier 702 and the negative input thereto. Capacitor 704 is similar to capacitor 504 discussed above with reference to FIG. 7 , and feedback diode 706 is similar to the feedback diode 604 discussed above with reference to FIG. 8 . [0044] Referring still to FIG. 9 , an offset voltage V off ( 708 ) is connected between the output of the differential amplifier 702 and the cathode of the feedback diode 706 to switch the pixel readout signals from a linear output to a logarithmic output, with the switching point defined by V off . Optionally, the switching point can be made adjustable by replacing the voltage V off with a capacitor, wherein V off is then selectively supplied to the capacitor 704 via a switch connected to a node between the feedback diode 706 and the capacitor 704 . [0045] More detailed descriptions of the output circuits shown in FIGS. 7-9 are provided in related U.S. application Ser. No. 10/226,326 entitled “A CMOS APS WITH STACKED AVALANCHE MULTIPLICATION LAYER WHICH PROVIDES LINEAR AND LOGARITHMIC PHOTO-CONVERSION CHARACTERISTICS,” the disclosure of which is hereby incorporated by reference, and which is commonly owned with and has the same inventorship as the present application. [0046] An example of an imaging device incorporating the present invention is shown in FIG. 10 . Specifically, an imaging apparatus 800 includes an image sensor 802 having a pixel array arranged according to a Bayer color filter pattern. A charge multiplying photoconversion layer such as a HARP layer is provided over each of the pixels in the array under the filter pattern. Each pixel 804 contains the protection and readout circuits in accordance with any one of the various embodiments discussed herein above. [0047] The imaging apparatus 800 further includes a row decoder 806 including a plurality of row select activation lines 808 corresponding in number to the number of rows in the pixel array of the image sensor 802 , wherein each line is connected to each row select switch in all the pixels in a respective row of the array. Similarly, column decoder 810 includes a plurality of column lines 812 , the number of which corresponds to the number of columns in the pixel array of the image sensor 802 . Each column line 812 is connected to the output sides of the row select switches in all the pixels in a respective column. [0048] To read the image data obtained by the image sensor 802 , controller 824 controls the row decoder 806 to sequentially activate the row select lines, whereby the row select switches for each pixel in a selected row is activated to thereby dump the image data from each respective pixel to the respective column line. Since each pixel in a row is connected to a different column line, the image data for each pixel is then read out to the image processor by sequentially activating all column select lines 813 to connect column lines 812 to column decoder 810 (via column select transistors 811 ). Thus, after activation of each row select line, the column select lines are sequentially activated to collect the image data in an orderly manner across the array. [0049] Upon reading the image data out of the pixel array, the data is passed through a number of processing circuits which, in linear order, generally include a sample and hold circuit 814 , an amplifier 816 , an analog to digital converter 818 , an image processor 820 , and an output device 822 . [0050] Without being limiting, such the imaging apparatus 800 could be part of a computer system, camera system, scanner, machine vision system, vehicle navigation system, video telephone, surveillance system, auto focus system, star tracker system, motion detection system, image stabilization system and other systems requiring an imager. [0051] The imaging apparatus 800 may also be connected to a processor system 850 , as shown in FIG. 11 , such as a computer system. A processor system 850 generally comprises a central processing unit (CPU) 852 that communicates with an input/output (I/O) device 854 over a bus 856 . The imaging apparatus 800 communicates with the system over bus 856 or a ported connection. The processor system 850 also includes random access memory (RAM) 858 , and, in the case of a computer system, may include peripheral devices such as a floppy disk drive 860 and a compact disc (CD) ROM drive 862 which also communicate with CPU 852 over the bus 856 . [0052] Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. Therefore, the present invention is to be limited not by the specific disclosure herein, but only by the appended claims.

An image sensor includes a pixel having a protection circuit connected to a charge multiplying photoconversion layer. The protection circuit prevents the pixel circuit from breaking down when the voltage in the pixel circuit reaches the operating voltage applied to the charge multiplying photoconversion layer in response to the image sensor being exposed to a strong light. The protection circuit causes additional voltage entering the pixel circuit from the charge multiplying photoconversion layer over a predetermined threshold voltage level to be dissipated from the storage node and any downstream components.

BACKGROUND OF THE INVENTION Such roller as a pinching roller used for such tape recorders as, for example, cassette tape recorders and VTR's has been conventionally formed as shown in FIG. 3. That is to say, in the drawing, the reference numeral 11 denotes a holder, 12 denotes a shaft, 13 denotes a spacer, 14 denotes an inner sleeve, 15 denotes a radial ball bearing, 16 denotes an outer sleeve made of brass, aluminum or the like and 17 denotes a roller body made of rubber or the like. In such conventional example, it has been common to provide a so-called double sealing structure by arranging sealing members 18 on both sides of the interior of the radial ball bearing 15 in order to prevent dusty fine powder such as rubber scraped off by the friction of the tape or the like in sliding contact with the surface of the roller body 17, from entering the radial ball bearing 15 through the path indicated by the arrows in FIG. 3. However, the above described conventional example has deficiency that the cost of the radial ball bearing 15 having sealing members 18 for preventing dust entry is high. SUMMARY OF THE INVENTION The present invention seeks to overcome the above mentioned deficiency and its object is to provide a roller wherein the formation of the radial ball bearing part is simplified, the manufacturing and assembling operations are made simple and the cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a first embodiment of a roller according to the present invention. FIG. 2 is a sectional view of a second embodiment of the present invention. FIG. 3 is of a conventional embodiment. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first embodiment of the present invention shown in FIG. 1, a columnar shaft 2 is supported between side pieces 1a and 1b of a holder 1, a hemispherical groove is made by cutting or the like in the middle of the shaft 2 to form a ball receiving part 2a and flange-shaped dust preventing projections 2b and 2c are formed over the entire periphery respectively on both sides of the ball receiving part 2a. A plurality of balls 3 are provided on the outer periphery of the ball receiving part 2a and are held by a substantially ring-shaped ball pressing member 4 arranged outside the balls 3. The ball pressing member 4 consists of two first and second tapered ball pressing members 4a and 4b, the members 4a and 4b being tapered, for example, substantially at 45 degrees at the inner end parts to contact and favorably hold the balls 3 and being provided with dust preventing projections 4c and 4d located respectively outside the projections 2b and 2c and extending toward the shaft 2. Slight clearances are formed respectively between the projections 2b and 2c and the inner peripheries of the first and second ball pressing members 4a and 4b and between the projections 4c and 4d and the outer periphery of the shaft 2. Further, the ball pressing member 4 is fixed to the inner peripheral surface of a cylindrical outer sleeve 5 arranged outside it. This outer sleeve 5 is, for example, die-cast and is fitted with a roller body 6 made of rubber on its peripheral surface. In assembling the elements, first of all, the roller body 6 is fitted on the outer peripheral surface of the outer sleeve 5 and is ground in advance on the outer peripheral surface. The first or second ball pressing member 4a or 4b on one side is pressed into a proper position on the inner periphery of the outer sleeve 5 and is fixed by a screwing means or binder. Then, the shaft 2 is inserted and set in a proper position with the already arranged first or second ball receiving member 4a or 4b through a proper jig (not illustrated). Then, a proper number of free balls 3 are put in together with grease or oil and are rotatably arranged between the outer periphery of the shaft 2 and the ball pressing member 4a or 4b on one side. Then the second or first ball pressing member 4b or 4a on the other side is pressed in and is fixed in a proper position on the inner periphery of the outer sleeve 5 by a screwing means or binder. While one side piece 1b of the holder 2 is bent and opened at the base end, the shaft 2 is locked at one end with a through hole of the other side piece 1a and then the above mentioned side piece 1b is bent back and is locked with the shaft 2 at the other end to easily assemble them. In the thus formed present invention, as no radial ball bearing is required, the cost can be substantially reduced. Such fine powder or dust of the rubber or the like as is slightly scraped off by a tape or the like running on the surface of the roller body 6 can be positively prevented by the dust preventing projections provided on both sides of the balls 3 from entering the ball part. Further, the component parts are so few and the respective members are of such comparatively simple forms that the assembling is easy. The second embodiment of the present invention shown in FIG. 2 is characterized in that the shaft 2 is left columnar, a ball receiveing part 2a' which is a separate member corresponding to the inner race of the radial ball bearing is provided substantially in the middle of the shaft 2, the balls 3 are arranged between this ball pressing member 4 and cylindrical spacers 7 are provided respectively on both sides of the above mentioned ball receiving part 2a'. In this embodiment, in assembling the roller, first of all, the roller body 6 is fitted to the outer sleeve 5, the first or second ball pressing member 4a or 4b on one side is secured as by being pressed in a proper poseition on the inner periphery of the outer sleeve 5, then the ball receiving part 2a' is positioned in the inner peripheral part of the already incorporated first or second ball pressing member 4a or 4b through a jig (not illustrated), a proper number of free balls 3 are inserted together with grease or oil, then the second or first ball pressing member 4b or 4a on the other side is pressed in and is fixed to the inner periphery of the outer sleeve 5 by a screwing means or binder, then the shaft 2 is inserted through the hole of the ball receiving part 2a' and the assembly completed by inserting the cylindrical spacers 7 from both directions may be fixed to the holder 1. By the way, a hemispherical groove to contact, hold and support the balls 3 is formed substantially in the middle of the ball receiving part 2a' and dust preventing projections 2b' and 2c' positioned respectively inside the projections 4c and 4d are provided respectively at both ends on the outer periphery of the ball receiving part 2a'. In this embodiment, there is an advantage that the shaft 2 is not required to be worked. As in the above, according to the present invention, there are effects that the formation is comparatively simple, the assembling is easy, the expensive radial bearing having conventional sealing members is not required and therefore the cost can be that much reduced.

This invention relates to a compact roller used as a tape recorder pinching roller for such as cassette tape recorders and VTR's or as a paper feeding roller for such as copying machines, facsimiles and printers.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a national stage application of PCT/EP01/00013 which was filed on Jan. 3, 2001, which in turn claims priority based on German patent application 10001035.0 filed Jan. 13, 2000. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT Not applicable BACKGROUND OF THE INVENTION The invention relates to an active compound chip having an integrated heating element for evaporating active compounds from the active compound chip. The invention furthermore relates to a process for the production of an active compound chip having an integrated heating element. Various devices for the evaporation of active compounds such as insecticides or fragrances are known. A device suitable for this purpose is a plate evaporater, consisting of a heating apparatus and insecticide plates. The insecticide plates consist of materials such as cellulose or cotton board, asbestos or ceramic and are impregnated with pyrethroid insecticides. The insecticide plates are placed on the heating apparatus, which can typically generate a temperature in range from 120 to 190° C. The insecticides are evaporated from the plates by the heat of the heating apparatus. The duration of action with plate evaporators is restricted to approximately 12 hours because of the high working temperature and the uneven release of active compound. A similar principle underlies the gel evaporator (DE 197 31 156 A1 ), in which insecticides are incorporated into a gel formulation. Another possibility for the evaporation of active compounds consists in the use of “liquid evaporators”, in which a liquid formulation of the active compound is continuously evaporated by warming by means of a wick system (GB 2 153 227). Polymeric active compound carriers, into which insecticidal active compounds are incorporated, are known from DE 196 05 581 A1. These polymeric active compound carriers theoretically have a working temperature of 60 to 150° C. In practice, however, it has been shown that a continuous rate of release of the active compound over a period of time of up to 60 days in a biologically active amount can only be realized using a large surface which is impracticable for the application or using a temperature in the range from 140 to 150° C. For the evaporation of the active compound, the polymeric active compound carriers are placed on a heating apparatus, such as is already known for plate and gel evaporators. Tests have shown that in the range from 110 to 100° C. the release rate of the active compound and thus the biological activity greatly decreases. All known evaporator systems need an external heating apparatus in order to generate the heat necessary for the evaporation of the active compound. Such a heating apparatus causes additional expense and needs a certain space at the site of application. Moreover, it leaves room for faulty operation. If, for example, a controllable heating apparatus is concerned, a wrong temperature adjustment can lead to over- or underdosage of the active compound. If a controllable heating apparatus is not concerned, different heating apparatuses must be bought for the evaporation of active compounds having different evaporation temperatures. A disadvantage of the known evaporator systems is furthermore the low efficiency caused by the heating apparatus. The heat transfer between the heating apparatus and the active compound carrier is poor, since complete contact between the surfaces of active compound carrier and heating plate is not achieved and an insulating layer of air can form between parts of the active compound carrier and the heating apparatus. This leads to the fact that it takes a long time until the active compound carrier is warmed so strongly that the active compound evaporates. High temperatures of the heating apparatus are needed in order to evaporate the active compound in an amount which is necessary, for example, for the effective control of insects. These high temperatures also border on the housing, so that there is a danger of burning for the user. At high temperatures, there is also the danger that other parts of the active compound formulation than the active compound itself evaporate and contribute to unnecessary pollution of the environment. The poor heat transfer furthermore leads to incomplete liberation of the active compound from the active compound carrier. In the case of polymeric active compound carriers which had been heated on a heating plate, a residue of up to 20% of active compound was measured in the active compound carrier. On account of the poor heat conductivity of the polymers and possibly occurring deformations of the active compound carriers, exact temperature control is not possible, so that uneven escape of active compound can occur. The known systems have the further disadvantage that the non-heated surfaces of the heating apparatus, in particular, are in some cases so cool that the released active compound immediately condenses on them again. BRIEF SUMMARY OF THE INVENTION It was an object of the invention to find a device for the evaporation of active compounds which manages without an external heating apparatus and thereby does not have the disadvantages associated with an external heating apparatus. The solution to the object according to the invention consists in an active compound chip comprising an active compound which is bound at room temperature, at least one heating element being located at least partly in the interior of the chip and the heating element having an electrical resistance and electrical contacts. The heating element can be heated and the active compound can be evaporated by applying an electrical voltage to the electrical contacts. The temperature in the specified heating element is controlled via the applied voltage U in combination with the resistance R of the heating element. Since the total heating power P of the heating element is converted into the warming of the active compound chip, an exact control of the escape of active compound is possible. The amount of the escaping active compound increases with the temperature of the heating element. The local distribution of the escape of active compound depends on the heat conductivity of the active compound chip and the geometry of heating element and chip. The heating element can consist of a conductive material which can be processed mechanically, such as ceramic, heat conductor (heating wire), vapor-deposited film or conductive plastic. The heating element can also consist of a heating resistance or a resistance known, for example, from the publication of Siemens Matushita Components GmbH u. Co KG (Order No. from Siemens: B 425-P2562 or on the Internet under www.siemens.com\pr\index.htm, pp. 19 to 40) having a positive temperature coefficient (PTC or alternatively called cold conductor). A PTC consists, for example, of a mixture of barium carbonate, titanium oxide and further materials. The electrical resistance of the heating element is preferably between 10 kΩ and 100 kΩ at 230V supply voltage and between 2 kΩ and 30 kΩ at 110V supply voltage. The electrical resistance R=ρ×1/A is determined on the one hand by the selection of the material for the heating element (specific resistance P) or the amount of electrically conductive material in the parent material, such as ceramic or plastic, on the other hand by the material thickness A and the length l of the heating element. The heating power P of the heating element is preferably between 0.1 W and 5 W and is dependent on the operating voltage U according to P=U 2 /R. Using a heating power of 0.1 W to 5 W, temperatures in the range from 60° C. to 140° C. can preferably be established. The heating element can assume any desired forms, which are selected depending on the desired heat distribution and surface of the heating element. In one embodiment, the heating element has the form of a meander having at least one bend, the two electrical contacts being located on the two ends of the meander. Preferably, the heating element has the form of two meanders having at least one bend, one electrical contact in each case being located on each end of the two meanders and it being possible for the electrical contacts facing one another of the two meanders to be connected to one another in an electrically conducting manner. This embodiment has the particular advantage that either both meanders can be contacted separately or together. The possibility thus exists to keep the heating power P=U 1 2 /R 1 +U 2 2 /R 2 constant even at different voltages. The meander form of the heating element guarantees a uniform heat distribution in the chip. In other embodiments, the heating element has the structure of a lattice or of honeycombs. Lattices or honeycombs likewise guarantee an even heat distribution in the chip. In a specific embodiment, the heating element having the lattice or honeycomb structure can be designed in two strips which in each case contacts at one end and are connected to one another in an electrically conducting manner at the end opposite to the contacting. The electrical contacts preferably consist of sheet brass or of copper. The geometric shape of the active compound chip having an integrated heating element depends on the field of application and on the manufacturing process. In the simplest case, the active compound chip forms a rectangular plate having electrical contacts in extension of the plate on one of the sides. If the active compound chip contains, for example, an active compound for controlling cockroaches, it can be necessary to apply the active compound chip at the base behind bars, so that it lies flats and as close as possible to the wall or bottom. In this case, the electrical connections are can be arranged perpendicular to the surface of the plate. The active compound chip having an integrated heating element in the form of a rectangular plate preferably has a length in the range from 10 to 100 mm, a breadth in the range from 5 to 100 mm and a thickness in the range from 3 to 20 mm. A number of heating elements can also be integrated into an active compound chip such that various areas of the active compound chip, which in each case are allocated to one heating element, can be heated in succession. In another embodiment, the heating element is not embedded in a flat chip, but the heating element is surrounded, according to its length, by the chip part comprising the active compound so that the shape of the heating element forms an image on the external shape of the active compound chip. The heating element can be attached directly to a current supply by means of suitably shaped electrical contacts. It can, however, also be attached to a current supply by means of a suitable adapter consisting of a holder and the power connection. One and the same adapter can be employed for active compound chips having different active compounds and thus different evaporation temperatures. It can have still further objects such as, for example, the picking up of voltage variations or the provision of additional functions. The active compound can be present pure or as an active compound mixture in liquid, gelatinous or in solid form. In this case, the active compound chip is provided with a surface layer which is impenetrable to the active compound or the active compound mixture in liquid, gelatinous or solid form and penetrable in gaseous form. As soon as the active compound or the active compound mixture becomes gaseous as a result of the temperature increase due to the heating apparatus, it can penetrate the surface layer. The liquid or gelatinous or solid active compound or the active compound mixture is present in a housing and the heating element is embedded in it. Alternatively, the active compound can also be bound to an active compound carrier, preferably this active compound carrier is a polymer. Particularly preferably, the active compound chip in this case consists essentially of the heating element and the active compound carrier containing active compound surrounding this. The active compound carrier of one preferred embodiment consists of mixtures which contain at least one active compound and least one polymer having a crystallite melting range between 100 and 300° C., preferably between 150 and 250° C., particularly preferably between 150 and 200° C. The softening range is confirmed in the case of amorphous thermoplastic polymers by the glass temperature and in the case of partially crystalline polymers by the melting temperature. Moreover, organic or inorganic auxiliaries such as stabilizers or dyes can be incorporated into the mixtures as further additives. Active compounds which can be used in all embodiments of the active compound carriers are insecticidal active compounds such as pyrethroids, acaricidal active compounds, fragrances or ethereal oils. Preferably, transfluthrin is used as active compound. Transfluthrin displays an insecticidal action against mosquitoes, flies and cockroaches. The pyrethroid active compounds preferably used are: 1) natural pyrethrum, 2) 3-allyl-2-methyl-cyclopent-2-en-4-on-1-yl d/l-cis/trans-chrysanthemate (allethrin/Pynamin®), 3) 3-allyl-2-methyl-cyclopent-2-en-4-on-1-yl d-cis/trans-chrysanthemate (Pynamin forte®), 4) d-3-allyl-2-methyl-cyclopent-2-en-4-on-1-yl d-trans-chrysanthemate (Exrin®), 5) 3-allyl-2-methyl-cyclopent-2-en-4-on-1-yl d-trans-chrysanthemate (Bioallethrino®), 6) N-(3,4,5,6-tetrahydrophthalimido)-methyl dl-cis/trans-chrysanthemate (phthalthrin, Neopynamin®), 7) 5-benzyl-3-furylmethyl d-cis/trans-chrysanthemate (resmethrin, Chryson forte®), 8) 5-(2-propargyl)-3-furylmethyl chrysanthemate (Furamethrin®), 9) 3-phenoxybenzyl-2,2-dimethyl-3-(2,2-dichlorovinyl) cyclopropane carboxylate (permethrin, Exmin®), 10) phenoxybenzyl d-cis/trans-chrysanthemate (phenothrin, Sumithrin®), 11) -cyanophenoxybenzylisopropyl-4-chlorophenyl acetate (fenvalerate, Sumicidin®), 12) (S)- -cyano-3-phenoxybenzyl-(1R,cis)-3-(2,2-dichlorovinyl)-2,2-dimethyl cyclopropanecarboxylate, 13) (R,S)- -cyano-3-phenoxybenzyl-(1R,1S)-cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethyl cyclopopanecarboxylate, 14) -cyano-3-phenoxybenzyl d-cis/trans-chrysanthemate, 15) 1-ethinyl-2-methyl-2-pentenyl cis/trans-chrysanthemate, 16) 1-ethinyl-2-methyl-2-pentenyl-2,2-dimethyl-3-(2-methyl-1-propenyl) cyclopropane-1-carboxylate, 17) 1-ethinyl-2-methyl-2-pentenyl-2,2,3,3-tetramethyl cyclopropanecarboxylate, 18) 1-ethinyl-2-methyl-2-pentenyl-2,2-dimethyl-3-(2,2-dichlorovinyl) cyclopropane-1-carboxylate, 19) 2,3,5,6-tetrafluorobenzyl-(+)-1R-trans-2,2-dimethyl-3-(2,2-dichlorovinyl) cyclopropanecarboxylate (transfluthrin, Bayothrin®) or mixtures of these active compounds. Particularly preferably, the active compounds used are 3-allyl-2-methyl-cyclopent-2en-4-on-1-yl d-cis/trans-chrysanthemate (Pynamin forte®) and 2,3,5,6-tetrafluorobenzyl-(+)-1R-trans-2,2-dimethyl-3-(2,2-dichlorovinyl) cyclopropanecarboxylate (transfluthrin). The acaricidal active compound preferably used is benzyl benzoate. Suitable fragrances are natural fragrances such as, for example, musk, civet, amber, castereum and similar fragrances: ajowa oil, almond oil, amber seeds absol., angelica root oil, aniseed oil, basil oil, laurel oil, benzoin resinoid, bergamot essence, birch oil, rosewood oil, broom absol., cajeput oil, cananga oil, gapiscum oil, caraway oil, cardamon oil, carrot seed oil oil, cassia oil, cedarwood oil, celery seed oil, cinnamon bark oil, citronella oil, oil of clary sage, oil of cloves, oil of cognac, coriander oil, cubeb oil, camphor oil, dill oil, tarragon oil. Eucalyptus oil, fennel oil, sweet, calbanum resinoid, garlic oil. Geranium oil, ginger oil, grapefruit oil, hop oil, hyacinth absol., jasmine absol., oil of juniper berries, labdanum resinoid, lavender oil, oil of laurel leaves, lemon oil, lemongrass oil, oil of lovage, oil of mace, mandarin oil, misoma absol., myrrh absol., mustard oil, narcissus absol., neroli oil, nutmeg oil, oak moss absol., olibanum resinoid, onion oil, opoponax resinoid, orange oil, orange blossom oil, iris concete, pepper oil, peppermint oil, peru balsam, petit grain oil, pine needle oil, rose absol., rose oil, rosemary oil, sandalwood oil, sage oil, spearmint oil, styrax oil, oil of thyme, tolu balsam, tonka beans absol., tuberose absol., turpentine oil, vanilla beans absol., vetiver oil, violet leaves absol., ylang-ylang oil and similar plant oils etc. Also suitable are synthetic fragrances such as pinene, limonene and similar hydrocarbons; 3,3,5-trimethylcyclohexanol, linalool, geraniol, nerol, citronellol, menthol, borneol, borneylmethoxycyclohexanol, benzyl alcohol, anisyl alcohol, cinnamyl alcohol, β-phenylethyl alcohol, cis-3-hexanol, terpineol and similar alcohols; anetholes, musk xylene, isoeugenol, methyleugenol and similar phenols; amylcinnamaldehyde, anisaldehyde, n-butyraldehyde, cuminaldehyde, cyclamenaldehyde, decylaldehyde, isobutyraldehyde, hexylaldehyde, heptylaldehyde, n-nonylaldehyde, nonadienol, citral, citronellal, hydroxycitronellal, benzaldehyde, methyl-nonylacetaldehyde nonylacetaldehyde, cinnamaldehyde, dodecanol, -hexylcinnamaldehyde, undecanal, heliotropin, vanillin, ethylvanillin and similar aldehydes, methyl amyl ketone, methyl β-naphthyl ketone, methyl nonyl ketone, musk ketone, diacetyl, acetylpropionyl, acetylbutyryl, carvone, methone, camphor, acetophenone, p-methylacetophenone, ionone, methylionone and similar lactones; amylbutyrolactone, diphenyl oxide, methyl phenylglycidate, nonylacetone, coumarin, cineol, ethylmethylphenyl glycidate and similar lactones or oxides, methyl formate, isopropyl formate, linalyl formate, ethyl acetate, octyl acetate, methyl acetate, benzyl acetate, cinnamyl acetate, butyl propionate, isoamyl acetate, isopropyl isobutyrate, geranyl isovalerate, allyl caproate, butyl heptylate, octyl caprylate, methyl heptinecarboxylate, methyl octine-carboxylate, isoamyl caprylate, methyl laurate, ethyl myristate, methyl myristate, ethyl benzoate, methylcarbinylphenyl acetate, isobutylphenyl acetate, methyl cinnamate, styracin, methyl salicylate, ethyl anisate, methyl anthranilate, ethyl pyruvate, ethyl- -butyl butyrate, benzyl propionate, butyl acetate, butyl butyrate, p-tert-butylcyclohexyl acetate, cedryl acetate, citronellyl acetate, citronellyl formate, p-cresyl acetate, ethyl butyrate, ethyl caproate, ethyl cinnamate, ethyl phenylacetate, ethylene brassylate, geranyl acetate, geranyl formate, isoamyl salicylate, isoamyl valerate, isobornyl acetate, linalyl acetate, methyl anthranilate, methyl dihydrojasmoate, nonyl acetate, βphenylethyl acetate, trichloromethylene phenyl-carbinylacetate, terpinyl acetate, vetiveryl acetate and similar esters. These fragrances can be used individually, or at least two thereof can be used as a mixture with one another. Besides the fragrance, the formulation according to the invention can optionally additionally contain the additives which are customary in the fragrance industry, such as patchouli oil or similar volatility-inhibiting agents, such as eugenol or similar viscosity-regulating agents. Polymeric materials used for the active compound carrier are preferably amorphous and partially crystalline polymers and mixtures of the two, which can be processed under thermoplastic conditions, i.e. as viscous melts, and whose softening range lies below the boiling point of the active compounds to be incorporated under normal pressure. The polymers are chosen for the appropriate active compound such that the active compound mixes at least partially with the polymers. Suitable amorphous polymers preferably used are: PVC (SOFT), polystyrene, styrene/butadiene, styrene/acrylonitrile, acrylonitrile/butadiene/styrene, polymethyl acrylate, amorphous polycycloolefins, cellulose esters, aromatic polycarbonates, amorphous aromatic polyamides, poly-phenylene ethers, poly(ether) sulphones, polyimides. Suitably partially crystalline polymers which are preferably used are: polyethylene, polypropylene, polybutylene, PVC (HARD), polyamide, polyether amides, polyester amides, polyoxymethylene, poly-4-methylpent-1-ene, polyethylene terephthalate, polybutylene terephthalate, polyimide, polyether (ether) ketone and polyurethanes. Preferred mixtures are, for example: blends of polycarbonates with polybutylene terephthalate, blends of polyamide-6 and styrene/acrylonitrile. Polypropylene, amorphous aromatic polyamides, aromatic polycarbonates and aromatic polyurethanes and ®TPX types, ®Desmopan 8410, ®Vestamid 1800, ®BAK 402-005 are particularly preferred. The mixtures can be stabilized with the aid of antioxidants by admixing a UV absorber to the formulation as an additive. UV absorbers which can be employed are all known UV absorbers. Those preferably employed are phenol derivatives, such as, for example, butylhydroxytoluene (BHT), butylhydroxyanisole (BHA), bisphenol derivatives, aryl-amines, such as, for example, phenylnaphthylamine, phenyl-β-naphthylamine, a condensate of phenetidine and acetone or the like or benzophenones. It is possible to use dyes, such as inorganic pigments, e.g. iron oxide, titanium oxide, ferric ferrocyanide and inorganic dyes, such as, for example, alizarin, azo and metal phthalocyanine dyes and metal salts, such as salts of iron, manganese, boron, copper, cobalt, molybdenum and zinc. By means of the active compound concentration and amount, the duration of action can be adjusted in a period of time of 1 to 60 10-hour nights. The active compound chips in general contain between 0.1 and 80% by weight, preferably between 0.2 and 40% by weight, particularly preferably between 1.0 and 20% by weight, of active compound. Additional functions can be integrated either into the chip or into the adapter. The active compound chip can additionally be equipped with an operating display. This can consist of an LED, preferably a bipolar LED, and can be connected in series, for example, with the heating element. Between the current supply and the contacts of the active compound chip, it is possible to employ a timer chip known per se. In addition to the contacts present, a resistance is then integrated into the active compound chip or into the adapter. This resistance should preferably be arranged asymmetrically, such that the active compound chip is contacted to the current supply or the timer chip only in one of two possible positions of incorporation. The incorporated resistance is controlled by the timer function set on the timer chip such that after the end of a preselected time the current contact terminates. The user has the possibility by simple rotation of the chip to choose between two types of operation (with timer/without timer). Alternatively, the choice between two different timer periods would also be conceivable. For the stabilization of the temperature in the case of variations of the ambient temperature, a resistance having a positive temperature coefficient can be incorporated into the apparatus. If the ambient temperature and thus the temperature in the chip falls, the temperature on the PTC thus decreases. As a result of the decrease in the temperature in the PTC, the resistance of the PTC also decreases and the PTC heats to compensate. For the production of an active compound chip in which the active compound or the active compound mixture is present in liquid, gelatinous or solid form, a heating element is sprayed onto an endless metal tape. The individual heating elements are subsequently punched out of the endless metal tape, the contacts are separated and the heating elements are enclosed in a housing. The active compound or the active compound mixture is added to the heating element in the housing, provided the housing does not yet contain the active compound or the active compound mixture, and the housing is sealed. Similarly, an active compound chip having a heating element consisting of two strips can be produced. Each strip is sprayed onto two endless metal tapes. One endless metal tape is cut between each two strips, the other endless metal tape between each strip. The heating elements produced in this manner are enclosed in a housing which contains the active compound carrier. For the integration of an operating display, the first metal tape can also be cut between each strip. An LED is then soldered in between each two strips. For the production of an active compound chip in which the active compound is bound to an active compound carrier, a heating element is sprayed onto at least one endless metal tape. The active compound carrier containing the active compound is subsequently sprayed around the heating element on the endless metal tape and the individual active compound chips are then punched out of the tape of active compound carriers on the endless metal tape. For the production of an active compound chip in which the active compound is bound to an active compound carrier and the active compound carrier is a polymer and the heating element is a conductive plastic, the heating element together with the active compound carrier can be extruded, in the form that, for example, a plastic wire is produced whose core forms the heating element and whose jacket forms the active compound carrier. This plastic wire can assume any desired shape, for example a meander shape. In a further embodiment, a heating element made of strips having a lattice or honeycomb structure is sprayed onto at least one endless metal tape. The individual heating elements are subsequently punched out of the endless metal tape and the contacts are optionally separated and the active compound or the active compound mixture is introduced into the honeycomb or lattice structure of the heating element using a doctor blade, namely in liquid, waxy or thermoplastic form. For the introduction using the doctor blade, the active compound or the active compound mixture is distributed into the interstices of the lattice or honeycomb structure. The heating element is then enclosed in the housing. The great advantage of the active compound chip according to the invention is that differently from all known systems, no external heating apparatus is necessary. The working temperature in each case specific for the determined active compound is generated in the active compound chip using the integrated heating apparatus itself. An over- or underdosage by the user by means of the use of a wrong heating power is excluded. The use is thus simpler, cheaper and safer. The active compound chip according to the invention advantageously has a high efficiency in the evaporation of the active compound, since the heat is produced by the resistance heater in the interior of the active compound carrier and is utilized for the evaporation of the active compound without losses. The heat energy is thus utilized efficiently. This also means that the heating temperatures for active compounds having low evaporation temperatures can be very low at below 90° C. without losses in the utilization of the active compound in comparison with conventional systems in which a comparable amount of active compound is released only at heating temperatures above 100° C. Using the active compound chip according to the invention, the danger of burning of the user when working with the device is reduced and the evaporation of other constituents of the active compound formulation than the active compound itself can also be reduced to zero. The active compound released is better utilized, since no condensation takes place on the heating apparatus. The low operating temperature simultaneously makes possible the use of temperature-labile active compounds which can no longer be employed at temperatures of over 100 to 120° C. In exactly the same way, because of the lower working temperature low-melting plastics such as polypropylene and polyethylene can be employed. As a result of the essentially complete liberation of the active compound, no residue remains in the active compound carrier, which facilitates disposal, in particular if biodegradable polymers are additionally used. The release of the active compound can take place in a controlled manner since the surface area and the temperature distribution can be defined and controlled accurately, unlike the systems using the heating apparatuses. The active compound chip according to the invention is flexible in application, since any desired forms can be used and there is no fixing of the space needed by a heating apparatus. If an adapter is to be used, this can be used with different active compounds for various active compound chips having an integrated heating element. The device according to the invention can be used for the control of insects such as mosquitoes, flies or cockroaches. It can also be used for the evaporation of fragrances or ethereal oils, e.g. in bathrooms or toilets. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. 1 Perspective view of a plastic plate having an integrated heating element. FIG. 2 Schematic representation of possible designs for the heating element. a . Meander form having one meander and two contacts. b . Meander form having two meanders and two contacts each. c . Meander form having two meanders which are connected in an electrically conducting manner. d . Meander form having two meanders which are contacted separately. e . Lattice form in two strips having an LED. FIG. 3 FIGS. 3 a to 3 g show the steps of a production process for the production of an active compound chip having an integrated heating element in lattice form and a light diode. FIG. 4 Average values of proportions of the evaporated substances over 45 cycles. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a perspective view of an active compound chip 1 having an integrated heating element 2 . The heating element 2 has the electrical contacts 3 and 4 . FIG. 2 a shows a heating element 2 in the form of a meander having seven bends 21 and the two contacts 3 , 4 in top view and in side view 2 . FIG. 2 b shows a heating element 22 in the form of two meanders having three bends 21 each and the electrical contacts 3 , 3 ′, 4 ′, 4 . FIG. 2 c shows a heating element 22 in the form of two meanders having three bends 21 each and the electrical contacts 3 , 3 ′, 4 ′, 4 in top view and in side view 22 ′. The contacts 3 ′ and 4 ′ are connected to one another in an electrically conducting manner. If a voltage of 230 V is applied between the contacts 3 and 4 and the resistance of one meander each is 20 kΩ, according to P=U 2 /R=(230 V) 2 /(20 kΩ+20 kΩ) approximately P=1.32 W of heating power results. FIG. 2 d shows a heating element 22 in the form of two meanders having three bends 21 each and the electrical contacts 3 , 3 ′, 4 ′, 4 in top view and in side view 22 ′. If a voltage of 110 V is applied between each of the contacts 3 and 3 ′ and 4 ′ and 4 and the resistance of each meander is 20 kΩ, according to P=U2/R=(110 V)2/ (20 kΩ)+(110 V) 2 /(20 kΩ) approximately P=1.32 W of heating power results. FIG. 2 e shows a heating element 23 in the form of a lattice having two strips 11 , 12 The contacts 3 , 4 are located at the two corresponding ends of the strips 11 , 12 . The opposite ends 13 and 14 are connected in an electrically conducting manner via a light diode 15 . The steps of a production process for the production of an active compound chip having an integrated heating element and light diode according to FIG. 2 e are shown in FIGS. 3 a to 3 g. Two perforated brass tapes 31, 32 run through a spraying machine and strip-shaped heating elements 23 of conductive plastic in the form of a lattice are sprayed onto the brass tapes with their ends 13 , 14 ( FIG. 3 a ). The brass tape 31 is cut between the ends 13 , 14 ( FIG. 3 b ). An LED 15 is soldered between the two free ends 13 , 14 ( FIG. 3 c ). The brass tape 32 is then separated between the contacts 3 , 4 and separate heating elements 23 are obtained ( FIG. 3 d ). Following this, each heating element 23 is enclosed in a housing subsection 33 ( FIG. 3 e ) and the active compound 34 is introduced into the housing ( FIG. 3 f ). Finally, the housing upper section 35 is mounted ( FIG. 3 g ). EXAMPLES Example 1 Assembly and Application an Active Compound Chip Having an Integrated Heating Apparatus A heating element 2 having a cross section of 1 mm and a length of 67 mm and an electrical resistance of about 15 Ω was cast into a plastic plate according to FIG. 1 made of polypropylene material and of 70 mm length, 30 mm breadth and 5 mm thickness. The heating element had the form of a meander. The plastic material of which the plastic plate consisted contained between 8.1% and 8.4%, altogether about 720 mg, of the active compound transfluthrin. The plastic plate was attached to the socket (230 V) via the electrical contacts 3 and 4 by means of an adapter with a mains receiver. The voltage at the electrical resistance of the active compound chip was 230 V. Within a few minutes, the wire in the plastic plate heated up to 65 to 70° C. and the active compound transfluthrin began to evaporate in a biologically active amount. The working temperature was kept in the range from 65 to 90° C. over a period of time of 8 hours. After 45 of these 8 hour cycles, it was still possible to detect a proportion of about 70% of the original amount of active compound in the active compound chip. A pause of 16 hours was made between two successive cycles. The room temperature during the experiment was 21 to 25° C. Example 2 Comparison of the Working Temperatures of Various Vaporator Systems The properties of an active compound chip having an integrated heating element according to example 1 has been compared with the properties of three other evaporator systems, which are also long-term systems, i.e. have a reservoir of active compound for a number of days. The first comparison system chosen was a gel evaporator. 1.6 g of the formulation of the gel evaporator had the following composition: 37.5% of pure Transfluthrin ® = 600.0 mg 4.5% of Aerosil 200 ® = 72.0 mg 0.03% of Sudan Blue 670 ® dye = 0.48 mg 2.0% of Baygona 226863 ® perfume oil = 32.0 mg 55.97% of Diphyl THT ® = 895.52 mg = 1600.00 mg The evaporation was carried out by means of an appropriate heating apparatus at a temperature of 100 to 110° C. The second comparison system chosen was a liquid evaporator. 35 g of the formulation of the liquid evaporator had the following composition: 0.88% of transfluthrin; = 0.308 g 67.12% of Isopar M; = 23.492 g 30.0% of Isopar V = 10.5 g 1.0% of butylhydroxy toluene = 0.35 g 1.0% of Deodorins B.Y.R. N 3 perfume oil = 0.35 g = 35.0 g The evaporation was carried out by means of an appropriate heating apparatus at a temperature of 125 to 135° C. The third comparison system chosen was a polymeric active compound carrier having an external heating apparatus. The same plastic material and the same amount of active compound as in example 1 was used. The evaporation was carried out by means of an appropriate heating apparatus at temperatures of 100° C. and 150° C. All experiments were carried out at a room temperature of 21 to 25° C. Table 1 shows the working temperatures measured for the various evaporator systems. The working temperature is that temperature at which an adequate biological action occurs. The comparison presented in Table 1 shows that the working temperature of the active compound chip having an integrated heating element at 65 to 90° C. is markedly below the working temperature of the known evaporator systems. The polymeric active compound carrier, which has the same composition as the active compound chip according to the invention as in example 1 and only, differently to the active compound chip according to the invention, has no integrated heating apparatus, but an external heating apparatus, showed a working temperature in the range from 140° C. to 150° C. At temperatures in the range from 110° C. and 100° C., the biological action noticeably decreased. The plate evaporator was used in its commercially obtainable form (PV 3 heater, DBK). TABLE 1 Working temperature of various evaporator systems in comparison System Temperature range Plate evaporator 140–150° C. Liquid evaporator 125–135° C. Gel evaporator 100–110° C. Active compound chip 65–90° C. Polymeric active 140–150° C. compound carrier Example 3 Comparison of the Evaporation Rates of Various Evaporator Systems A long-term test of the evaporation rate of active compound was carried out in comparison of the active compound chip with the gel evaporator and the liquid evaporator. The cycle duration was 8 hours with 16 hours interruption between two successive cycles. The working temperature of the systems was chosen as in Table 1 such that it was possible to achieve a comparable biological action. The results of the comparison of the evaporation rates over 45 cycles are shown in Tables 2 to 5. Table 2 shows the release rates of the total formulations and Table 3 the average values of these release rates. Table 4 indicates how much active compound was released in the individual cycles and Table 5 the average value of the release rates of the active compound. The weight loss of the total formulation of the individual systems is composed of evaporated active compound and evaporation of additional constituents of the formulation. The amount of the total formulation evaporated in the gel evaporator and in the liquid evaporator is markedly higher than in the active compound chip (Table 2). A comparison of the amount of evaporated active compound shows that the amount of active compound evaporated in the active compound chip, the amount of active compound evaporated in the gel evaporator and in the liquid evaporator corresponds down to 1 to 2 mg/cycle (Table 4). This confirms that the chosen working temperatures lead to comparable biological actions due to a comparable amount of evaporated active compound. If, however, the proportion of active compound of the total amount evaporated is considered, it is seen that that this amount in the active compound chip is 100% from the 4th cycle, between 25% and 35% for the gel evaporator and below 1% for the liquid evaporator. It emerges from Table 6 how much active compound was evaporated in relation to the overall amount evaporated. This was on average 91% over all 45 cycles in the active compound chip, 27% in the gel evaporator and 0.75% in the liquid evaporator. In the starting cycles (1st to 7th cycle), the proportion of active compound in all three systems is lower than in the last cycles (40th to 45th cycle). FIG. 4 illustrates how the total amount of substance evaporated is composed of proportions of active compound and other proportions for the three systems tested. The good ratio of active compound to the total amount evaporated in the active compound chip is to be attributed to the formulation associated with the low working temperature which is possible due to the integrated heating apparatus. The evaporation temperature for the polypropylene material in which the active compound is embedded is markedly above 100° C., while for the evaporation of an adequate amount of active compound a working temperature of below 100° C. suffices. In all comparison systems, the temperature which is necessary for the evaporation of an adequate amount of active compound is also over 100° C., so that large proportions of the other material are automatically evaporated with the active compound. The almost 100% proportion of active compound in the total amount evaporated in the active compound chip has the advantage of lower pollution of the environment with comparable biological activity in relation to the known evaporator systems. The lower pollution of the environment with the active compound chip in comparison is also manifested by the uniform, low evaporation rate. The evaporation rate over the total experimental period for the active compound chip has an absolute variation width which is markedly below the variation width for the gel evaporator and the liquid evaporator (Table 3). The absolute variation width of the evaporation rate of active compound over the total experimental period is comparable in all three cases investigated and is between 0.6 mg/cycle (liquid evaporator) and 0.9 mg/cycle (gel evaporator) (Table 4). TABLE 2 Release rate of the total formulation Active compound Liquid chip Gel evaporator evaporator Weight loss Weight loss Weight loss Cycle [mg/cycle] [mg/cycle] [mg/cycle] 1 17.6 37 1010 2 11.2 38 890 3 11.3 33 887 4 7.5 33 885 5 6.8 26 880 6 5.4 26 870 7 2.8 26 860 8 6.7 26 850 9 4.3 26 850 10 5.7 26 840 11 5.7 26 840 12 5.3 22 840 13 4.8 22 830 14 6.2 22 820 15 5.0 22 820 16 3.6 22 820 17 2.6 22 820 18 3.0 19 820 19 4.3 19 820 20 4.1 18 800 21 3.8 18 800 22 4.2 16 800 23 3.5 16 790 24 3.2 16 790 25 3.2 16 790 26 3.1 16 780 27 3.0 16 770 28 3.5 17 770 29 4.5 17 770 30 4.3 11 770 31 3.6 11 770 32 3.4 10 770 33 2.4 10 770 34 3.4 10 770 35 4.3 10 780 36 1.9 10 760 37 1.8 10 760 38 1.8 10 760 39 2.5 10 770 40 2.7 9 775 41 2.8 9 760 42 3.0 7 760 45 3.0 6 680 TABLE 3 Average values of the release rate of the total formulation Average value Standard deviation +/− System [mg]/cycle [mg]/cycle Active compound chip 4.6 1.45 Gel evaporator 18.4 4.1 Liquid evaporator 809 28 TABLE 4 Release rate of the active compound Active compound Liquid chip Gel evaporator evaporator Weight loss Weight loss Weight loss Cycle [mg/cycle] [mg/cycle] [mg/cycle] 1 7.1 9.3 6.8 2 7.2 9.5 7 3 7.3 7.6 7.5 4 7.5 7.6 6.5 5 6.8 6.8 7.9 6 5.4 6.6 7.2 7 2.8 6.7 5.5 8 6.7 6.7 7.6 9 4.3 6.8 6.5 10 5.7 6.9 7.6 11 5.7 7.1 7.5 12 5.3 5.9 5.3 13 4.8 5.5 7.4 14 6.2 5.7 4.8 15 5 5.8 6.5 16 3.6 5.9 6.4 17 2.6 6 6.3 18 3 4.7 7.1 19 4.3 4.5 6.5 20 4.1 4.4 7.2 21 3.8 4.3 7 22 4.2 4.1 7 23 3.5 4.2 7.1 24 3.2 4.3 7.1 25 3.2 4.4 7 26 3.1 4.1 7.1 27 3 4.2 6.9 28 3.5 4.4 6.2 29 4.5 4.3 6.1 30 4.3 3.9 5.8 31 3.6 3.8 5.6 32 3.4 3.3 5.2 33 2.4 3.2 5.1 34 3.4 3.2 5 35 4.3 3.1 4.5 36 1.9 3 4.4 37 1.8 3.3 4.3 38 1.8 3.1 4.2 39 2.5 3 4.1 40 2.7 2.7 4 41 2.8 2.5 3.9 42 3 2.4 3.8 45 3 2.3 3.8 TABLE 5 Average values of the release rate of the active compound Average value Standard deviation +/− [mg]/cycle [mg]/cycle Active compound chip 4.2 0.8 Gel evaporator 4.9 0.9 Liquid evaporator 6.1 0.6 TABLE 6 Proportion of the active compound in the total amount of the substances evaporated (average value over 45 cycles) in [%] Starting cycles End cycles Ø over 45 cycles (1–7) (40–45) Active compound chip 91 86 100 Gel evaporator 27 25 70 Liquid evaporator 0.75 0.5 3.0 Example 4 Comparison of the Amounts of Active Compound of Various Evaporator Systems Necessary for a Comparable Biological Action An advantage of the active compound chip is seen in that an identical amount of active compound evaporated as in the gel evaporator and in the liquid evaporator has a better biological action. This lies in the fact that in the gel evaporator and in the liquid evaporator a part of the active compound evaporated is directly lost again by condensation on cool sites of the heating apparatus, while the active compound evaporated in the active compound chip is almost completely utilized. Table 7 indicates how much active compound must in each case be evaporated using the active compound chip, the gel evaporator and the liquid evaporator in order that a comparable biological action occurs. A reduction in the needed amount of active compound evaporated has a positive effect on the reduction of the environmental pollution, the longevity and the temperature. TABLE 7 Amount of active compound which produces the same biological action Active compound chip Gel evaporator Liquid evaporator Amount per cycle [mg/8 h] 4.2 4.9 6.1 Amount per hour (index) [mg/h] 0.5 (100) 0.6 (120) 0.8 (160) Example 5 The Biological Action of the Active Compound Chips The biological action of active compound chips having an integrated heating element on the mosquitoes of the species Aedes Aegypti, sensitive was demonstrated in example 5. The experiment was carried out in a room of 36 m 3 size, having an open window, at a temperature of 20 to 28° C. and rel. room humidity of 17 to 34%. The working temperature was 65 to 90° C. Active compound chips according to example 1 were TABLE 8 Biological action of the active compound chip Formulation Example 1 Operating Knockdown action time/testing Mosquito after min or % dead after days estimate after after h (Hours) hours 50% 100% 9 h 24 h 1st day 0 46′ 55′ 100 100 1 16′ 32′ 100 100 2  9′ 28′ 100 100 3 11′ 23′ 100 100 4 13′ 19′ 100 100 5 12′ 23′ 100 100 8 hours 6 23′ 43′ 100 100 7 33′ 1 h 00′ 100 100 8 26′ >8 h  88 100 2 days 0 44′ 1 h 14′ 100 100 1 59′ 1 h 19′ 100 100 2 36′ 1 h 03′ 100 100 3 19′ 49′ 100 100 4 19′ 53′ 100 100 5 46′ 1 h 12′ 100 100 6 29′ 1 h 17′ 100 100 7 24′ 43′ 100 100 16 hours 8 14′ 32′ 100 100 3 days 0 40′ 48′ 100 100 1  9′ 13′ 100 100 2  3′  5′ 100 100 3  3′  6′ 100 100 4  2′  4′ 100 100 5  3′  7′ 100 100 6  5′ 11′ 100 100 7  7′ 16′ 100 100 24 hours 8  4′ >1 h  90 100 The results show the expected biological action of the system. The application time can be adjusted by variation of the active compound concentration in the active compound chip.

Active compound chip and process for the production of an active compound chip comprising an active compound which is bound at room temperature, at least one heating element being located at least partly in the interior of the chip and the heating element having an electrical resistance and at least two electrical contacts.

This application claims the benefit of U.S. Provisional Application No. 61/716,677 filed Oct. 22, 2012, which is hereby incorporated by reference in its entirety as if fully set forth herein. FIELD OF THE INVENTION This invention relates to metal detectors with means to transmit, receive, and process signals. BACKGROUND OF THE INVENTION Induction metal detectors are generally designed to transmit either continuous wave (CW) signals, so-called frequency-domain (FD) detectors or to use pulsed or rectangular signals, so-called time-domain (TD) detectors. For the purpose of this invention description, a transmit waveform is understood to mean coil current unless otherwise noted. Often both types of designs use substantially similar receiver architectures: a preamp followed by one or more synchronous demodulation channels, integration and/or filtering, analog-to-digital conversion, and digital signal processing. To date, commercialized metal detectors that mix FD and TD in the same design are rare and tend to be user-selected to one mode or the other, but do not run simultaneously. Time-domain detectors are often referred to as pulse induction (PI) detectors, as most designs create a short pulse of current using a switched coil. When the current is switched off, the result is a high voltage flyback. The decay of the flyback is usually critically damped with a damping resistor, and the decay of the flyback is monitored for perturbations due to nearby metal targets. See U.S. Pat. No. 5,414,411. A typical pulse induction metal detector transmits a single pulse width duration of a consistent peak current amplitude, resulting in a single response that must be processed. Some methods have been described which use either multiple pulse width durations (see FIG. 1, U.S. Pat. No. 5,576,624) such as a series of short pulses 11 and long pulses 12. Some methods create differing peak current amplitudes (see FIG. 2 U.S. Pat. No. 6,653,838), such as a series of high current pulses 13 and a low current pulses 14. Either of the methods can produce variable responses to eddy current targets or to ferromagnetic ground or both. Typically such multiple responses are processed through multiple receive channels, whether such channels are realized in hardware, software, or a combination. These methods are analogous to so-called “multifrequency” metal detectors which use frequency-domain techniques. PI detectors are often used in military and humanitarian demining. Some land mines include a magnetic trigger, so this application requires the use of bipolar pulsing to avoid the creation of a non-zero net magnetic field (see U.S. Pat. No. 6,653,838 and FIG. 3) which shows a series of positive pulses 15 and negative pulses 16. Additional benefits are possible with bipolar pulsing. Subtracting the responses of the two polarities substantially cancels induced signals from the Earth's magnetic field and other low-frequency interferers while maintaining eddy current induced target responses. In many applications, a desirable feature in a metal detector is the ability to distinguish between various types of targets such as ferrous versus non-ferrous or low conductor versus high conductor. Currently available PI detectors generally exhibit poor discrimination capabilities. Frequency domain designs utilizing CW signals, especially sine waves, often use the target phase response to determine target characteristics. However, PI detectors generally achieve greater detection depths than do CW detectors, especially in ground which is high in mineralization or exhibits high magnetic viscosity. The ability to tune out mineralized ground is generally referred to as Ground Balance (GB). While both PI and CW designs include methods of ground balance, PI is inherently less sensitive to mineralization than CW. However, the GB method in many PI designs involves the subtraction of two signal samples, which not only reduces depth in general. The subtraction can also completely subtract out certain target responses, resulting in so-called “target holes” where particular targets cannot be detected at all. Needs exist for improved metal detectors. SUMMARY OF THE INVENTION This invention covers methods of generating and processing both types of signals in a single metal detector and running both types, CW and PI, simultaneously. The highly desirable solution combines the advantages of each system: the depth of PI with the discrimination of CW, plus a GB method which does not suffer from loss of depth or target holes. The invention provides a new and improved metal detector having one or more transmit coils for producing a cyclic transmitted magnetic field in response to a cyclic transmit current. Each transmit current cycle has one or more transmit current pulses that exhibit approximately a half-sine waveform during turn-on, which sinusoidally rises to a peak current, and which at or past the peak current is truncated by substantially shutting off the coil current. The shut off is followed by a turn-off time in which the applied transmit current is substantially zero. A transmit circuitry for generating the transmit current pulses applied to the one or more transmit coils has one or more switching networks for switching the one or more coils to appropriate drive circuitry having a unipolar or bipolar power supply voltage and one or more series-connected resonant capacitors for the purpose of producing a substantially half-sine response during the turn-on time. One or more receive coils receive a response signal created from the transmitted magnetic field and its effect on a surrounding matrix and conductive targets. A receive circuitry has a plurality of receive channels. Each channel has sampling circuitry and processing circuitry. The transmit current pulse is a truncated half-sine, which is truncated substantially close to the peak of the half-sine current waveform and after the peak of the half-sine current waveform. A transmit current pulse is followed by a turn-off time in which the applied transmit current is substantially zero, which is followed by a substantially identical transmit current pulse of opposite current polarity. A plurality of transmit current pulses are truncated half-sine current pulses of different pulse width durations with the same characteristic sinusoidal resonance response. Each pulse width duration is effected by a switching network for switching the one or more coils to drive circuitry that includes a series-connected resonance capacitor having a value selected to produce a truncated half-sine current response in which each pulse width duration has substantially the same truncation current level relative to its peak current level. In one form, the drive circuitry for each pulse width duration is powered by the same power supply voltage. In another embodiment, the drive circuitry for each pulse width duration is powered by a different power supply voltage. The power supply voltage is scaled according to the pulse width duration and resonance capacitor selection such that each pulse width duration has substantially the same current amplitude. One receive channel samples a received flyback response created by the truncation of the transmit current. The flyback response is called the flyback sample. Another receive channel samples a received half-sine response after the peak of the transmit half-sine current but before the truncation point, which is called the ground sample. The flyback sample and the ground sample are combined, and either or both samples are adjusted such that the combined response due to a ground matrix is substantially minimized. The metal detector has adjustment for one or more of sample delay, sample width, or sample gain. The adjustment is under the manual control of the user, or is under the automated control of the metal detector. A receive circuit samples a received half-sine response substantially at the peak of the transmit half-sine current which is called the X sample. The X sample is processed to determined characteristics of the ground matrix. The results are used to automatically adjust the ground sample such that the combined response of the flyback sample and the ground sample due to the ground matrix is substantially minimized. In one embodiment, a receive circuit samples a received half-sine response shortly after the beginning of the transmit half-sine current turn-on point, which is called the R sample. The X sample and the R sample are processed and compared to determined probable target type. In one embodiment of a metal detector, a receive channel samples a received flyback response created by the truncation of the transmit current which is called the flyback sample. The flyback sample is used to determine the presence of a conductive target, and the R sample is used to determine probable target type. The position of the R sample may be adjusted to change the response of certain target types for the purpose of accepting or rejecting certain target responses. In one embodiment, a plurality of pulse width durations are received and processed. The results are scaled and subtracted to substantially eliminate the response of saltwater. These and further and other objects and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification, with the claims and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows varied pulse width in PI detectors. FIG. 2 shows differing peak current amplitudes in PI detectors. FIG. 3 shows bipolar pulsing in PI detectors. FIG. 4 shows an H-bridge driver in a CW detector. FIG. 5 shows an H-bridge driver in a PI detector. FIG. 6 shows a circuit of the present invention. FIG. 7 shows three of many possible responses. FIG. 8 shows coil current allowed to proceed beyond a peak for current cutoff. FIG. 9 shows bipolar truncated half-sine with two different widths and frequencies. FIG. 10 shows a circuit to implement bipolar transmission with two different frequencies. FIG. 11 shows a circuit with separate supply voltages for multiple frequencies. FIG. 12 shows a circuit similar to FIG. 6 with self-switching cross coupling. FIG. 13 shows cross coupled devices driven directly from NMOS devices. FIG. 14 shows typical waveform deflections from a single transmit pulse. DETAILED DESCRIPTION Bipolar transmit signals can be generated in a number of ways. A straightforward approach is to use an H-bridge driver with coil 21 , resistor 22 , capacitor 23 , and switches 31 , 32 , 33 , 34 which can drive current through a coil in either direction. This method has been used in both CW detectors 10 ( FIG. 4 ) and PI detectors 12 ( FIG. 5 ), the major difference being the addition of flyback diodes 41 , 42 , 43 , 44 in the PI version. In the CW method coil 21 can be resonated with a parallel capacitor 23 to generate a sine wave or left unresonated to generate a ramp waveform. A benefit of the H-bridge driver is that the responses of both current polarities are substantially matched. By adding a series-resonant capacitor to the PI H-bridge design it is possible to achieve a sinusoidal response during a turn-on duration along with a transient response at the turn-off point. FIG. 6 shows a circuit with a series-resonant capacitor 24 added. FIG. 7 shows three of many possible responses. The response 51 is similar to what some traditional PI transmit circuits achieve. Response 52 shows a quarter-sine response, whereby the H-bridge is turned off exactly at the peak of the sinusoid current. This has a performance benefit. In PI detectors it is desirable to have the coil charge current plateau to a reasonably constant level (di/dt=0) to allow forward-induced target eddy currents to die out before the coil current is shut off. Any residual forward-induced eddy currents will subtract from the desired reverse-induced eddy currents, reducing the overall target signal just after the coil turn-off event. The series resonant capacitor substantially speeds up this process compared to the normal exponential response of the coil alone. Response 53 shows a half-sine response, when the H-bridge is turned off exactly at the zero crossing of the sinusoid current. The frequency of the sinusoidal portion of the transmit signal is found by the traditional LC resonance equation, f = 1 2 ⁢ π ⁢ L ⁢ ⁢ C where L is the search coil 21 and reactance C is the series resonant capacitor 24 capacitance. Therefore, for a given L-C combination the clock timing can be varied to achieve a transient cutoff at any point during the sinusoid. It is also possible to implement a full sinusoidal (CW) current response. In current metal detector designs there is a trade-off between continuous wave, which offers good target identification through phase analysis, and pulse induction which offers greater depth through an impulse response. A hybrid system is desirable in which both a phase analysis and an impulse response are simultaneously present. This can be effected with the quarter-wave response 53 , but it is further advantageous to allow the coil current to proceed somewhat beyond the peak before cutting it off. As shown in FIG. 8 , this produces definite regions where the slope of the current is zero at the peaks, 55 and allows sampling the received signal on both sides 56 of the zero slope for the purposes of ground balance and determining target phase response. This waveform will be further referred to as a “truncated half-sine.” The truncated half-sine method and other circuit solutions are described in “Hybrid Induction Balance/Pulse Induction Metal Detector” (Earle), U.S. Ser. No. 61/398,298, now U.S. patent application Ser. No. 13/166,004. As mentioned before, some PI detectors utilize two or more transmit pulse widths to extract more information on ground and target signals. In continuous wave detectors, multiple sinusoidal frequencies are often used for the same purpose. The truncated half-sine can accomplish both methods simultaneously. FIG. 9 shows a (bipolar) truncated half-sine with two different pulse widths and resulting “frequencies.” Pulses 57 have a relatively wide pulse width and low frequency, and pulses 58 have a relatively narrow pulse width and high frequency. The multi-frequency truncated half-sine can be realized using an expanded version of the circuit in FIG. 6 . FIG. 10 shows a circuit which can implement bipolar transmission with the equivalence of two different frequencies. Capacitor 24 sets the frequency of a first half-sine, with transistor 31 , 32 , 33 , 34 providing the switching. Capacitor 25 sets the frequency of a second half-sine, with transistors 31 , 32 , 37 , 38 providing the switching. Diodes 47 and 48 are added near switches 37 and 38 . A relatively larger capacitor value of capacitor 24 , coupled with a longer turn-on time, produces a lower frequency, while a smaller capacitor 25 and shorter turn-on time produces a higher frequency. Additional frequencies may be added in similar fashion. This circuit does not quite produce the waveform in FIG. 9 . As both the capacitance and the turn-on time decrease, the amplitude of the resulting truncated half-sine also decreases. The result is a loss of sensitivity for the higher frequency, which is often compensated for by running multiple cycles of short pulses per each single long pulse cycle. See U.S. Pat. No. 5,537,041. This can better be remedied by using separate supply voltages for the multiple frequencies as shown in FIG. 11 . A lower frequency may be implemented with a larger capacitor 24 driven from a lower voltage 26 using transistors 31 , 32 , 33 , 34 . A higher frequency may be implemented with a smaller capacitor 25 driven from a higher voltage 27 using transistors 35 , 36 , 37 , 38 . Transistors 32 and 36 and diodes 42 and 46 are redundant and may be combined. The result is the desired waveform in FIG. 9 . All of the circuits described so far use both high-side (P-side) and low-side (N-side) switches driven from clock sources. Each switch may require its own unique clock signal even though some clock signals may have identical timing. This will often depend on drive voltage level needs. A simplification is to make some of the switches self-switching by connecting them in a cross-coupled manner. FIG. 12 shows the circuit in FIG. 6 having self-switching. In some configurations better switching performance is achieved when the cross-coupled devices are driven directly from the NMOS devices, as shown in FIG. 13 . Multifrequency truncated half-sine drivers such as in FIG. 11 may be similarly simplified. There are many variations of these concepts that will become apparent to anyone skilled in the art. In general, other switching devices such as bipolar transistors may be used in lieu of MOSFETs, and many of the flyback diodes may be eliminated. Most circuits have been shown as being powered from “+V” to ground, but a negative-referenced supply or bipolar supplies may be implemented. Unipolar current waveforms instead of bipolar may implemented. In FIG. 6 switches 33 and 34 may be eliminated, and capacitor 24 may be tied to a fixed voltage. In cross-coupled designs, cross-coupled N-side switches with clocked P-side switches may be implemented and, in fact, may be advantageous in some cases. The truncated half-sine transmit waveform results in an equivalent CW portion during the coil turn-on time and a PI portion at the point of coil switch-off. In order to receive and process the signal from the CW portion an induction-balanced coil is required. If a mono coil is used, then the PI portion can still be processed, but the CW portion cannot. While the transmit waveforms shown thus far represent the current through the transmit coil, the receive waveforms will represent the voltage at the receive coil. FIG. 14 shows typical received waveform deflections for a single transmit pulse 50 . The nominal receive waveform 60 during the turn-on time 50 is depicted as flat but will depend on the induction balance characteristics of the coil assembly. Response waveforms 61 , 62 , 63 , 64 are shown as typical deflections of the nominal waveform 60 . Similarly, at turn-off 59 the nominal receive waveform 70 will have a certain transient response dependent on the characteristics of the coil assembly and response waveforms 71 , 72 , 73 , 74 are shown as typical deflections of the nominal waveform 70 . During turn-on 50 both magnetic responses (ferrite and small iron) and eddy responses (nonferrous and large iron) produce deflections which exhibit pivoting about the nominal response 60 . This pivoting corresponds to phase shifts in traditional CW responses. Ferrite response 61 tilts counterclockwise about pivot point 67 . Because ferrite is theoretically lossless and ideally exhibits no phase shift, this should occur at the peak 55 of the transmit current where di/dt is zero. This point is called the “ground pivot.” A US nickel response 63 exhibits a clockwise tilt at a much earlier pivot point 65 , while a US silver dollar response 64 exhibits a clockwise tilt at a later pivot point 66 . Magnetic iron response 62 can either be viewed as a clockwise tilt with a pivot point occurring sometime before the start of turn-on period 50 , or as a counterclockwise tilt with a pivot point occurring sometime after the turn-off point 59 . In either case, most ferrous targets produce a negative response across the turn-on time 50 . The target responses at the turn-off point 59 follow traditional PI responses. All targets and ground exhibit the same deflection polarity, with the ground response 71 having approximately a l/t response and conductive responses 72 , 73 , 74 having approximately an exponential response compared to the nominal response 70 . In traditional ground balanced PI detectors a late sample is subtracted from an early sample in proper proportion to eliminate the ground response. The drawback is that all target responses are weakened at least a little, and a so-called “target hole” arises where a small range of target responses are completely or nearly eliminated. It should be noted that the deflections described are valid for one polarity of the transmit waveform, and for a bipolar transmitter the opposite polarity transmit waveform will produce opposite deflections. It should also be noted that the polarities of the deflections depend on how the coils are wound and connected. It is therefore understood that all waveform descriptions are illustrative and not absolute. Timing pulses 80 , 81 , 82 , 83 represent the sample points of the receive waveform for the purpose of signal processing. There are many ways to accomplish this including various synchronous demodulation schemes and direct sampling, and these various methods are within the scope of this invention. Timing pulse 83 is used to sample the response after the turn-off point 59 in a manner similar to traditional PI. This sample (herein called the “main” sample) produces responses of a consistent polarity for all conductors (e.g. US nickel 72 , US silver dollar 73 , and iron 74 ), and a relatively weaker response 71 for ground but also of the same polarity as conductors. The delay of pulse 83 relative to the turn-off point 59 is usually a few microseconds to 10's of microseconds, with a typical delay of 10 μs. Timing pulse 82 is used to sample the turn-on response 50 after the ground pivot point 67 . At this sample (herein called the “ground” sample) all conductive targets will have a negative polarity while ground will have a positive polarity. By properly scaling and subtracting the ground sample from the main sample it is possible to cancel the ground signal. At the same time, responses from all conductors will get stronger, which is opposite from traditional PI ground subtraction methods, and the “target hole” problem of traditional PI detectors is also eliminated. Any combination of sample delay, sample pulse width, or signal gain may be applied to either or both of the main sample or ground sample to effect ground signal cancellation. This may be manually controlled by the user or implemented as an automated system which tracks ground conditions. Timing pulse 80 is used to sample early in the turn-on response 50 and timing pulse 81 is used to sample at or very near the ground pivot point. These samples can be processed in a manner similar to CW as near-quadrature signal responses that produce amplitude and phase information. This phase information can then be used to determine the ground response by using techniques similar to those used in CW, and it is possible to effect an automated ground tracking method to compensate for ground variability by adjusting the scaling of the main and/or the ground signals. The phase can also be used to identify and discriminate conductive targets, also in a manner similar to those used in CW. Multiple pulse widths (frequencies) can produce varied responses to targets. For example, a relatively long pulse width (low frequency) may produce a stronger response to high conductors, and a relatively short pulse width (high frequency) may produce a stronger response to low conductors. Multiple pulse widths can be processed using individual processing channels or may be combined into common processing channels if the half-sine response curves are substantially alike. When using separate processing channels the results from two or more frequencies can be used to subtract the responses from salt water, which is advantageous when using a metal detector in a saltwater location. While the invention has been described with reference to specific embodiments, modifications and variations of the invention may be constructed without departing from the scope of the invention, which is defined in the following claims.

This invention relates to a metal detector where a coil is used to transmit a periodic magnetic field to energize metal objects that are concealed and often buried or hidden in a matrix (ground) containing ferromagnetic minerals. There are many difficult and often simultaneous challenges, such as detecting large deep targets, detecting minutely small targets, identifying target properties, ignoring the ferromagnetic matrix, avoiding a net magnetic field which can trigger magnetic sensors in land mines, and ignoring conductive salt responses. Either time-domain or frequency domain methods have been used to address these challenges with mixed levels of success. The ability to simultaneously use time-domain and frequency-domain methods can expand detection capability. Techniques are presented for achieving these goals.

CROSS-REFERENCE TO RELATED APPLICATION(S) This application is a continuation of U.S. patent application Ser. No. 12/171,183 filed Jul. 10, 2008 now abandoned. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated circuit architecture, that when coupled to a bi-stable circuit, prevents the bi-stable circuit from being effected by incident radiation that causes Single-Event-Upsets (SEU) and/or Single-Event-Gate-Rupture (SEGR). 2. Prior Art Bi-stable circuits, and particularly CMOS bi-stable flip-flops, latches, and static-random-access-memories (SRAM), that have the ability to self-re-enforce a programmed state (such as Q=1 and Q_bar=0, or BIT=1 and BIT_bar=0) to be referred to later by the system that programmed the present state are well known in the art. A typical application for a bi-stable flip-flop or latch is in combinational logic using previous and present states, such as D type flip flops, SR latches, and JK flip flops. Another typical example for a bi-stable circuit is in a static random access memory cell, which is generally used in sizable arrays that remember programmed data as long as power is applied. However, bi-stable circuits are also used in many different functional blocks and applications, and then usually implemented in integrated circuits. The general purpose of bi-stable circuits is to remain in one of two possible programmed states, however when used in space, radiation that is naturally present in space can become incident on the integrated bi-stable circuit and cause the bi-stable circuit to change to the opposite state or change to a state other than what it was programmed to remain. Incident radiation changing the programmed state of a bi-stable circuit can cause undesirable effects to the system that uses the programmed state of the bi-stable circuit for system operations. An example of this would be static-random-access-memory in a satellite used to provide navigation information or secure military communication, that when the static-random-access-memory is unknowingly flipped to the opposite state by incident radiation, provides incorrect navigation information, or incorrect and communication for military command and control. Therefore it is desirable to provide protection to space-based bi-stable circuits that prevents unknown and undesirable state changes to the bi-stable circuit due to incident radiation. Most existing bi-stable circuits that are hardened, or less susceptible to the effects of incident radiation in space, are manufactured as integrated circuits in special fabrication process that are expensive and not always adequate in providing acceptable levels of protection for the bi-stable circuit in space. The expense of special fabrication processes that manufacture hardened bi-stable circuits drive the cost of hardened circuits very high. Some designs exist that protect bi-stable circuits from unknown and undesirable state changes due to incident radiation and do not need to be manufactured in special fabrication processes and are known as radiation-hardened-by-design (RHBD) circuits. The RHBD bi-stable circuits are large (smallest most effective RHBD SRAM consists of 12 transistors), and are slow due to the size and complexity of design required to make a bi-stable circuit RHBD. Therefore, what is desired is a small, fast, generic integrated circuit architecture that can be coupled to any integrated bi-stable circuit making it immune to unknown and unwanted circuit changes due to incident radiation, that can be manufactured in a typical, non-specialized, in-expensive, integrated circuit manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS Many features and objects of the present invention and the manner of attaining them will become apparent and the invention itself will be best understood by reference to the following description of preferred embodiments taken in conjunction with the accompanying drawings, wherein: FIG. 1 is a transistor-level schematic of a four-transistor two-capacitor (4T2C) Radiation Single-Events-Effects (SEE) suppression device according to a first embodiment of the present invention. FIG. 2 is a block diagram of a peripheral bi-stable circuit in an SRAM circuit configuration and a transistor-level schematic of the four-transistor two-capacitor (4T2C) Radiation Single-Events-Effects (SEE) suppression device according to a second embodiment of the present invention. FIG. 3 is a block diagram of a peripheral bi-stable circuit in a Flip-Flop or Latch circuit configuration and a transistor-level schematic of the four-transistor two-capacitor (4T2C) Radiation Single-Event-Effects (SEE) suppression device according to a third embodiment of the present invention. FIG. 4 is a block diagram of a peripheral bi-stable circuit in a Flip-Flop or Latch circuit configuration and a transistor-level schematic of the four-transistor two-capacitor (4T2C) Radiation Single-Event-Effects (SEE) suppression device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with the present invention there is provided an integrated circuit architecture, consisting of 4 transistors and 2 capacitors (4T2C), that when coupled to the output nodes of any bi-stable circuit, the bi-stable circuit will be completely immune to the adverse effects of incident radiation that causes Single-Event-Upset (SEU) and Single-Event-Gate-Rupture (SEGR). Also in accordance with the present invention there is provided an integrated circuit architecture, consisting of 2 transistors and 1 capacitor (2T1C), that when coupled to the output nodes of a bi-stable circuit, the bi-stable circuit will be completely immune to the adverse effects of incident radiation that causes Single-Event-Upset (SEU) and Single-Event-Gate-Rupture (SEGR) in one of the two possible bi-stable circuit states. The 2 transistor, 1 capacitor (2T1C) integrated circuit architecture is intended to be used as a Single-Event-Upset detector since it only protects the bi-stable circuit in one state. For example, when the 2 transistor, 1 capacitor circuit is coupled to a bi-stable circuit in such a way that the circuit is not protected, when incident radiation changes the state of the bi-stable circuit, the state created by incident radiation will be captured and protected until purposefully reset by the system. This serves as a very valuable Single-Event-Upset detector that is used for alerts and allows for possible compensation of other parts of the integrated circuit. Following is a list of reference numerals used in the Figures: FIG. Nomenclature Description 1 4T2C Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 1 2T1C_1 Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 1 2T1C_2 Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 1 N1 N-type Transistor Device 1 P1 P-type Transistor Device 1 N2 N-type Transistor Device 1 P2 P-type Transistor Device 1 C1 Capacitor Device 1 C2 Capacitor Device 1 Cont1 Optional Capacitor Device Control Node 1 Cont2 Optional Capacitor Device Control Node 1 CS1 Common Source Node 1 CS2 Common Source Node 1 Q Bi-Directional Input/Output 1 Q_BAR Bi-Directional Input/Output 1 VD_N High Power Supply 1 VD_P Low Power Supply 2 Peripheral Peripheral Bi-Stable Circuit in SRAM SRAM Configuration 2 FF Bi-Stable Circuit 2 Q Bi-Directional Input/Output 2 Q_BAR Bi-Directional Input/Output 2 SP1 Series Pass Element 2 SP2 Series Pass Element 2 WR Write/Read Control Signal 2 BIT LINE Bi-Directional Input/Output 2 BIT_BAR LINE Bi-Directional Input/Output 2 4T2C Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 2 2T1C1 Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2 2T1C 2 Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2 N1 N-type Transistor Device 2 P1 P-type Transistor Device 2 N2 N-type Transistor Device 2 P2 P-type Transistor Device 2 C1 Capacitor device 2 C2 Capacitor device 2 Cont1 Optional Capacitor device Control Node 2 Cont2 Optional Capacitor device Control Node 2 CS1 Common Source Node 2 CS2 Common Source Node 2 VD_N High Power Supply 2 VD_P Low Power Supply 3 Peripheral Peripheral Bi-Stable Circuit in a Flip-Flop FF/LATCH or LATCH Configuration 3 LG1 Logic Gate(s) 3 LG2 Logic Gate(s) 3 IN1_1 to IN1_n 1 to n optional inputs 3 IN2_1 to IN1_e 1 to e optional inputs 3 OUT1_1 to 1 to m optional outputs OUT1_m 3 OUT2_1 to 1 to f optional outputs OUT2_f 3 Q Bi-Directional Input/Output 3 Q_BAR Bi-Directional Input/Output 3 4T2C Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 3 2T1C_1 Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 3 2T1C_2 Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 3 N1 N-type Transistor Device 3 P1 P-type Transistor Device 3 N2 N-type Transistor Device 3 P2 P-type Transistor Device 3 C1 Capacitor device 3 C2 Capacitor device 3 Cont1 Optional Capacitor device Control Node 3 Cont2 Optional Capacitor device Control Node 3 CE1 Common Emitter Node 3 CE2 Common Emitter Node 3 VD_N High Power Supply 3 VD_P Low Power Supply 4 Peripheral Peripheral Bi-Stable Circuit in a Flip-Flop FF/Latch or LATCH Configuration 4 LG1 Logic Gate(s) 4 LG2 Logic Gate(s) 4 IN1_1 to IN1_n 1 to n optional inputs 4 IN2_1 to IN1_e 1 to 3 optional inputs 4 OUT1_1 to 1 to m optional outputs OUT1_m 4 OUT2_1 to 1 to f optional outputs OUT2_f 4 Q Bi-Directional Input/Output 4 Q_BAR Bi-Directional Input/Output 4 4T2C Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4 2T1C1 Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 4 2T1C 2 Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 4 N1 N-type Transistor Device 4 P1 P-type Transistor Device 4 N2 N-type Transistor Device 4 P2 P-type Transistor Device 4 Cl Capacitor device 4 C2 Capacitor device 4 Cont1 Optional Capacitor device Control Node 4 Cont2 Optional Capacitor device Control Node 4 CE1 Common Emitter Node 4 CE2 Common Emitter Node 4 VD_N High Power Supply 4 VD_P Lower Power Supply First Embodiment FIG. 1 FIG. 1 is a transistor level circuit diagram showing a Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C according to a first embodiment of this invention. The Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C includes a first Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 , a second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 , a first optional capacitor device control line Cont 1 , a second optional capacitor device control line Cont 2 , a first Bi-Directional Input/Output terminal Q, and a second Bi-Directional Input/Output terminal Q_BAR. The first Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 includes an N-type transistor device N 1 , a P-type transistor device P 1 , a capacitor device C 1 , a Common Source Terminal CS 1 , a high power supply node VD_N, and a low power supply node VD_P. The N-type transistor device N 1 having a drain type terminal coupled to the high power supply node VD_N, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and a source type terminal coupled to the Common Source Terminal CS 1 . The P-type transistor device P 1 having a drain type terminal coupled to the low power supply node VD_P, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and a source type terminal coupled to the Common Source Terminal CS 1 . The capacitor device C 1 having a first terminal coupled to the Common Source Terminal CS 1 , a second terminal coupled to the Bi-Directional Input/Output terminal Q, and an optional capacitor device control terminal coupled to Ccont 1 . The second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 includes an N-type transistor device N 2 , a P-type transistor device P 2 , a capacitor device C 2 , a Common Source Terminal CS 2 , a high power supply node VD_N, and a low power supply node VD_P. The N-type transistor device N 2 having a drain type terminal coupled to the high power supply node VD_N, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q, and a source type terminal coupled to the Common Source Terminal CS 2 . The P-type transistor device P 2 having a drain type terminal coupled to the low power supply node VD_P, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q, and a source type terminal coupled to the Common Source Terminal CS 2 . The capacitor device C 2 having a first terminal coupled to the Common Source Terminal CS 2 , a second terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and an optional capacitor device control terminal coupled to Ccont 2 . The first and second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C_ 1 and 2T1C_ 2 are symmetrical and have components with identical aspect ratios and values. The operation of the first and second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C_ 1 and 2T1C_ 2 are substantially the same when either static or variable capacitors are used. The sizes of transistors will depend on the trans-conductance parameters of individual wafer foundries. The size of capacitors will depend on parameters of individual wafer foundries and the expected magnitude and duration of Single-Event-Effects (SEE). The capacitors need to retain enough charge, after the Single-Event-Effects have subsided, to “remember” the original state of the bi-stable circuit. The Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C is a symmetrical device and therefore has the same operation with respect to either of the two possible orientations: the second terminal of capacitor device C 1 coupled to Bi-Directional Input/Output Terminal Q and second terminal of capacitor device C 2 coupled to Bi-Directional Input/Output Terminal Q_BAR, OR the second terminal of capacitor device C 1 coupled to Bi-Directional Input/Output Terminal Q_BAR and second terminal of capacitor device C 2 coupled to Bi-Directional Input/Output Terminal Q. It does not matter what type of capacitor devices are used, as long as the capacitor device retains enough charge to “remember” the circuit's original state until after the Single-Event-Effect (SEE) subsides. The amount of capacitance that is required is based on the trans-conductance of the transistor-devices, which is dependent on the specific fabrication process, and the magnitude and duration of the expected Single-Event-Effect (SEE). The capacitor device may be a fixed value capacitor, or a variable value capacitor, which is the reason for the optional capacitor device control lines. The function of fixed value capacitor devices and variable value capacitor devices is substantially the same. When the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C is coupled to a bi-stable circuit, it protects the bi-stable circuit from unwanted and unknown changes in the bi-stable circuit's present state due to energy being deposited by incident radiation. There are a total of eight possible scenarios in which incident radiation may affect a change in the present state of a bi-stable circuit. Four of the eight possible scenarios re-enforce the bi-stable circuit's present state producing no unwanted and unknown changes in the bi-stable circuit's present state, and therefore are of no interest as illustrated in Table 1, scenarios 5 through 8. Table 1, scenarios 1 through 4, represent occurrences where incident radiation can affect an un-wanted and un-known change in the bi-stable circuit's present state and therefore are of interest. Therefore the operational description of the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C will be based on table 1, scenarios 1 through 4, describing how the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C eliminates the adverse effects of incident radiation on bi-stable circuits. TABLE 1 Node Node Strike Polarity Scenario “Q” “Q_BAR” Node of Strike Effect 1 High Low “Q” Negative Upset Possible 2 High Low “Q_BAR” Positive Upset Possible 3 Low High “Q” Positive Upset Possible 4 Low High “Q_BAR” Negative Upset Possible 5 High Low “Q” Positive Re-enforcing 6 High Low “Q_BAR” Negative Re-enforcing 7 Low High “Q” Negative Re-enforcing 8 Low High “Q_BAR” Positive Re-enforcing The High and Low, described for nodes “Q” and “Q_BAR” in table 1, are produced by the steady state of a bi-stable circuit that the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C is coupled to, but not shown in this embodiment. Subsequent embodiments do show the same scenarios with examples of various bi-stable circuits. The Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C is initially best understood by itself without added complicating circuitry. Table 1, Scenario 1 (Steady State): Initial static conditions are node “Q” high and node “Q_BAR” low. The external bi-stable circuit settling in this present or static state brings about the particular static condition for this scenario: A high on node “Q” turns on N-type transistor device N 2 , and turns off P-type transistor device P 2 forcing node CS 2 high. Note the configuration of the N-type transistor devices and P-type transistor devices are opposite to the normal inverter configuration. With node CS 2 high and node “Q_BAR” low, the first terminal (right) of C 2 is charged high and the second terminal (left) of C 2 is charged low. A low on node “Q_BAR” turns on P-type transistor device P 1 , and turns off N-type transistor device N 1 forcing node CS 1 low. With node CS 1 low and node “Q” high, the first terminal (left) of C 1 is charged low and the second terminal (right) of C 1 is charged high. Table 1, Scenario 1 (Steady State with Incident Radiation): An energetic particle having a negative polarity and striking node “Q,” pushes the voltage on node “Q” of the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C from high to low producing the following result: The node “Q” being forced from high to low due to incident radiation, charge pumps the voltage on node CS 1 in the negative direction. The magnitude of the negative voltage on node CS 1 is limited by the source to body diode connection of the N-type transistor device N 1 , which prevents Single-Event-Gate-Rupture (SEGR). As the voltage on node CS 1 goes negative due to the charge pumping of capacitor device C 1 , the source of the N-type transistor device N 1 is pulled low producing a gate to source voltage sufficient enough to turn on the N-type transistor device N 1 , pulling the voltage at node CS 1 back toward a high voltage level. This reverses the charge pumping action and forces the node “Q” toward its original high voltage state. The low forced on node “Q,” due to the incident radiation, has also simultaneously turned the P-type transistor device P 2 on and the N-type transistor device N 2 off. As the P-type transistor device P 2 turns on, node CS 2 is brought low. As node CS 2 is brought low, the node “Q_BAR” is charged pumped low, which strongly re-enforces the original state of node “Q_BAR.” The level of the negative charge pumping on the node “Q_BAR” would be limited by the drain to body diode connection of an N-type transistor device in the bi-stable circuit that is coupled to node “Q_BAR.” Table 1, Scenario 2 (Steady State): Initial static conditions are node “Q” high and node “Q_BAR” low. The external bi-stable circuit settling in this present or static state brings about the particular static condition for this scenario: A high on node “Q” turns on N-type transistor device N 2 , and turns off P-type transistor device P 2 forcing node CS 2 high. Note the configuration of the N-type transistor devices and P-type transistor devices are opposite to the normal inverter configuration. With node CS 2 high and node “Q_BAR” low, the first terminal (right) of C 2 is charged high and the second terminal (left) of C 2 is charged low. A low on node “Q_BAR” turns on P-type transistor device P 1 , and turns off N-type transistor device N 1 forcing node CS 1 low. With node CS 1 low and node “Q” high, the first terminal (left) of C 1 is charged low and the second terminal (right) of C 1 is charged high. Table 1, Scenario 2 (Steady State with Incident Radiation): An energetic particle having a positive polarity and striking node “Q_BAR,” pushes the voltage on node “Q_BAR” of the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C from low to high producing the following result: The node “Q_BAR” being forced from low to high due to incident radiation, charge pumps the voltage on node CS 2 in the positive direction. The magnitude of the positive voltage on node CS 2 is limited by the source to body diode connection of the P-type transistor device P 2 , which prevents Single-Event-Gate-Rupture (SEGR). As the voltage on node CS 2 goes positive due to the charge pumping of capacitor device C 2 , the source of the P-type transistor device P 2 is pulled low producing a gate to source voltage sufficient enough to turn on the P-type transistor device P 2 , pulling the voltage at node CS 2 back toward a low voltage level. This reverses the charge pumping action and forces the node “Q_BAR” toward its original low voltage state. The high forced on node “Q_BAR,” due to the incident radiation, has also simultaneously turned the N-type transistor device N 1 on, and the N-type transistor device N 2 off. As the N-type transistor device N 1 turns on, node CS 1 is brought high. As node CS 1 is brought high, the node “Q” is charged pumped high, which strongly re-enforces the original state of node “Q.” The level of the positive charge pumping on the node “Q” would be limited by the drain to body diode connection of a P-type transistor device in the bi-stable circuit that is coupled to node “Q.” Table 1, Scenario 3 (Steady State): Initial static conditions are node “Q” low and node “Q_BAR” high. The external bi-stable circuit settling in this present or static state brings about the particular static condition for this scenario: A low on node “Q” turns on P-type transistor device P 2 , and turns off N-type transistor device N 2 forcing node CS 2 low. Note the configuration of the N-type transistor devices and P-type transistor devices are opposite to the normal inverter configuration. With node CS 2 low and node “Q_BAR” high, the first terminal (right) of C 2 is charged low and the second terminal (left) of C 2 is charged high. A high on node “Q_BAR” turns on N-type transistor device N 1 , and turns off P-type transistor device P 1 forcing node CS 1 high. With node CS 1 high and node “Q” low, the first terminal (left) of C 1 is charged high and the second terminal (right) of C 1 is charged low. Table 1, Scenario 3 (Steady State with Incident Radiation): An energetic particle having a positive polarity and striking node “Q,” pushes the voltage on node “Q” of the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C from low to high producing the following result: The node “Q” being forced from low to high due to incident radiation, charge pumps the voltage on node CS 1 in the positive direction. The magnitude of the positive voltage on node CS 1 is limited by the source to body diode connection of the P-type transistor device P 1 , which prevents Single-Event-Gate-Rupture (SEGR). As the voltage on node CS 1 goes positive due to the charge pumping of capacitor device C 1 , the source of the P-type transistor device P 1 is pulled high producing a gate to source voltage sufficient enough to turn on the P-type transistor device P 1 , pulling the voltage at node CS 1 back toward a low voltage level. This reverses the charge pumping action and forces the node “Q” toward its original low voltage state. The high forced on node “Q,” due to the incident radiation, has also simultaneously turned the N-type transistor device N 2 on and the P-type transistor device P 2 off. As the N-type transistor device N 2 turns on, node CS 2 is brought high. As node CS 2 is brought high, the node “Q_BAR” is charged pumped high, which strongly re-enforces the original state of node “Q_BAR.” The level of the positive charge pumping on the node “Q_BAR” would be limited by the drain to body diode connection of an P-type transistor device in the bi-stable circuit that is coupled to node “Q_BAR.” Table 1, Scenario 4 (Steady State): Initial static conditions are node “Q” low and node “Q_BAR” high. The external bi-stable circuit settling in this present or static state brings about the particular static condition for this scenario: A low on node “Q” turns on P-type transistor device P 2 , and turns off N-type transistor device N 2 forcing node CS 2 low. Note the configuration of the N-type transistor devices and P-type transistor devices are opposite to the normal inverter configuration. With node CS 2 low and node “Q_BAR” high, the first terminal (right) of C 2 is charged low and the second terminal (left) of C 2 is charged high. A high on node “Q_BAR” turns on N-type transistor device N 1 , and turns off P-type transistor device P 1 forcing node CS 1 high. With node CS 1 high and node “Q” low, the first terminal (left) of C 1 is charged high and the second terminal (right) of C 1 is charged low. Table 1, Scenario 4 (Steady State with Incident Radiation): An energetic particle having a negative polarity and striking node “Q_BAR,” pushes the voltage on node “Q_BAR” of the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C from high to low producing the following result: The node “Q_BAR” being forced from high to low due to incident radiation, charge pumps the voltage on node CS 2 in the negative direction. The magnitude of the negative voltage on node CS 2 is limited by the source to body diode connection of the N-type transistor device N 1 , which prevents Single-Event-Gate-Rupture (SEGR). As the voltage on node CS 2 goes negative due to the charge pumping of capacitor device C 2 , the source of the N-type transistor device N 2 is pulled low producing a gate to source voltage sufficient enough to turn on the N-type transistor device N 2 , pulling the voltage at node CS 2 back toward a high voltage level. This reverses the charge pumping action and forces the node “Q_BAR” toward its original high voltage state. The low forced on node “Q_BAR,” due to the incident radiation, has also simultaneously turned the P-type transistor device P 1 on and the N-type transistor device N 1 off. As the P-type transistor device P 1 turns on, node CS 1 is brought low. As node CS 1 is brought low, the node “Q” is charged pumped low, which strongly re-enforces the original state of node “Q.” The level of the negative charge pumping on the node “Q” would be limited by the drain to body diode connection of an N-type transistor device in the bi-stable circuit that is coupled to node “Q.” Second Embodiment FIG. 2 FIG. 2 is a block diagram of a peripheral bi-stable circuit in an SRAM circuit configuration Peripheral SRAM and a transistor level circuit diagram showing a Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C according to a second embodiment of this invention. The Peripheral SRAM circuit includes a Bi-Stable Circuit FF, a first Series-Pass-Element SP 1 , a second Series-Pass-Element SP 2 , a Write/Read control line WR, a first Bi-Directional data line BIT LINE, and a second Bi-Directional data line BIT_BAR LINE. The Bi-Stable Circuit FF having a first Bi-Directional Input/Output terminal Q and a second Bi-Directional Input/Output terminal Q_BAR. The first Series-Pass-Element SP 1 having an input control terminal coupled to WR, a first Bi-Directional Input/Output terminal coupled to Bi-Directional data line BIT LINE, and a second Bi-Directional Input/Output terminal coupled to the Bi-Directional Input/Output terminal Q. The Second Series-Pass-Element SP 2 having an input control terminal coupled to WR, a first Bi-Directional Input/Output terminal coupled to Bi-Directional data line BIT_BAR LINE, and a second Bi-Directional Input/Output terminal coupled to the Bi-Directional Input/Output terminal Q_BAR. The Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C includes a first Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 , a second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 , a first optional capacitor device control line Cont 1 , a second optional capacitor device control line Cont 2 , a first Bi-Directional Input/Output terminal Q, and a second Bi-Directional Input/Output terminal Q_BAR. The first Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 includes an N-type transistor device N 1 , a P-type transistor device P 1 , a capacitor device C 1 , a Common Source Terminal CS 1 , a high power supply node VD_N, and a low power supply node VD_P. The N-type transistor device N 1 having a drain type terminal coupled to the high power supply node VD_N, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and a source type terminal coupled to the Common Source Terminal CS 1 . The P-type transistor device P 1 having a drain type terminal coupled to the low power supply node VD_P, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and a source type terminal coupled to the Common Source Terminal CS 1 . The capacitor device C 1 having a first terminal coupled to the Common Source Terminal CS 1 , a second terminal coupled to the Bi-Directional Input/Output terminal Q, and an optional capacitor device control terminal coupled to Ccont 1 . The second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 includes an N-type transistor device N 2 , a P-type transistor device P 2 , a capacitor device C 2 , a Common Source Terminal CS 2 , a high power supply node VD_N, and a low power supply node VD_P. The N-type transistor device N 2 having a drain type terminal coupled to the high power supply node VD_N, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q, and a source type terminal coupled to the Common Source Terminal CS 2 . The P-type transistor device P 2 having a drain type terminal coupled to the low power supply node VD_P, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q, and a source type terminal coupled to the Common Source Terminal CS 2 . The capacitor device C 2 having a first terminal coupled to the Common Source Terminal CS 2 , a second terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and an optional capacitor device control terminal coupled to Ccont 2 . The first and second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C_ 1 and 2T1C_ 2 are symmetrical and have components with identical aspect ratios and values. The operation of the first and second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C_ 1 and 2T1C_ 2 are substantially the same when either static or variable capacitors are use. The sizes of transistors will depend on the trans-conductance parameters of individual wafer foundries. The size of capacitors will depend on parameters of individual wafer foundries and the expected magnitude and duration of Single-Event-Effects. The capacitors need to retain enough charge, after the Single-Event-Effects have subsided, to “remember” the original state of the bi-stable circuit. The operation of the circuit depicted in the block diagram of FIG. 2 , Peripheral SRAM, is well known within the art. The operation of the circuit depicted in the block diagram of FIG. 2 , Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C, is substantially the same as the operation described for the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C in the FIRST EMBODIMENT. The Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C is very useful as a circuit architecture without being included in a Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C. The Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C protects against the effects of incident radiation strongly in one direction and weakly in the other direction, when coupled to a bi-stable circuit, which has two stable states or two possible directions for data/state storage. This makes the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C circuit architecture an optimal circuit architecture used, in conjunction with a bi-stable circuit, as a radiation sensor that senses a Single-Event-Upset (SEU) and safely stores the condition that resulted in the Single-Event-Upset (SEU) event. When a Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C and the bi-stable circuit is biased in a weak and known state, and a radioactive ion strikes causing a Single-Event-Upset (SEU) is incident on the circuit, the Single-Event-Upset (SEU) forces the circuit to change from one state, which was originally biased so that the circuit was weak against Single-Event-Upsets (SEU), to the other bi-stable state, which automatically puts the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C and the bi-stable circuit it is coupled to, into a very strongly protected state against Single-Event-Upset (SEU) events. The Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C, and the bi-stable circuit it is coupled to, now stores the state that indicates a Single-Event-Upset (SEU) occurred and that state can be used by the system, the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C and bi-stable circuit is embedded in, to alert other parts of the system thus allowing system to react if necessary. The actual biasing of the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C and bi-stable circuit may be arbitrary, and depends on the fact that the probability of an equal and oppositely charged ion striking the same node that was previously struck, thus resetting the circuit to it's original state and thus masking that a Single-Event-Upset (SEU) occurred, in such a time that is faster than the governing system operates, is so low, that the probability of this event occurring may be ignored. The probability of this “resetting” event may be practically eliminated by the addition of a second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C coupled to a bi-stable circuit, also acting as a sensor. It is recommended that the number of Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C coupled to their respective bi-stable circuits, be enough to cover an area sufficiently large enough to detect Single-Event-Upset (SEU) events based on the rate or frequency of ion strikes, which are well known for various orbits in space. An example of the construction of the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C coupled to a bi-stable circuit is illustrated in FIG. 2 by excluding the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 . TABLE 2 SEU Event Total Percent Pulse Deposited Improvement Cell Under Strike Width Current Charge Over Native Test Result Q Q_BAR Polarity Node Seconds Amps Coulombs SRAM Cell Peripheral SRAM 1 L H POS Q 1.62E−10 4.55E−05 7.37E−15 NA Cell without the 2 H L POS Q_BAR 1.62E−10 4.55E−05 7.37E−15 NA Two-Transistor 3 H L NEG Q 1.62E−10 6.45E−05 1.04E−14 NA One-Capacitor 4 L H NEG Q_BAR 1.62E−10 6.45E−05 1.04E−14 NA Radiation Effects Suppression Circuits 2T1C_1 and 2T1C_2 Peripheral SRAM 1 L H POS Q 1.62E−10 1.00E+02 1.62E−08 219,809,900% Cell only with the 2 H L POS Q_BAR 1.62E−10 2.36E−04 3.83E−14      420% Two-Transistor 3 H L NEG Q 1.62E−10 2.35E+01 3.81E−09  36,634,520% One-Capacitor 4 L H NEG Q_BAR 1.62E−10 1.19E−03 1.92E−13     1,746% Radiation Effects Suppression Circuits 2T1C_1 Peripheral SRAM 1 L H POS Q 1.62E−10 2.36E−04 3.83E−14      420% Cell only with the 2 H L POS Q_BAR 1.62E−10 1.00E+02 1.62E−08 219,809,900% Two-Transistor 3 H L NEG Q 1.62E−10 1.19E−03 1.92E−13     1,746% One-Capacitor 4 L H NEG Q_BAR 1.62E−10 2.35E+01 3.81E−09  36,634,520% Radiation Effects Suppression Circuits 2T1C_2 Table 2 shows the simulated results of three circuits architectures. The first is the Peripheral SRAM without the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 and without the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 . This circuit architecture provides baseline data. The second is the Peripheral SRAM with the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 and without the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 . The third is the Peripheral SRAM without the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 and with the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 . The first circuit architecture, the standalone Peripheral SRAM, shows that a Single-Event-Upset (SEU) depositing 7.37 fC of positive charge on a node that is LOW, or 10.4 fC of negative charge on a node that is high, causes the Peripheral SRAM to perform an unwanted state change. It is interesting to note that alpha particles found terrestrially can generate these levels of charge, making the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C and Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C circuit architectures quite suited for use on the planet's surface as well as in space. The second circuit architecture, the Peripheral SRAM having the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 coupled to it, shows that in comparison, to the first circuit architecture of the standalone Peripheral SRAM, the required charge from a Single-Event-Upset (SEU) to perform an unwanted change in the state of the Peripheral SRAM, has been increased from the baseline of 0% to 219,780,120% depending on the circuit's initial conditions, the charge polarity of the incident ion, and the polarity of the node that incident ion strikes. In the second configuration of the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 coupled to the Peripheral SRAM, having “Q” node high and the “Q_BAR” node low as in Table 2, conditions the circuit to easily sense the effects of a positively charged ion incident on the low node “Q_BAR,” causing an unwanted state change by depositing 38.3 fC of charge or more. Since most features of radiation hardened integrated circuits are protected against incident ions that deposit much greater than 38.3 fC, this circuit architecture is therefore sensitive enough to alert the system it is embedded in, to the presence of ionic activity. For example when a satellite passes through various layers of the Van Allen Belts, or during increased Solar Flare Activity, the ions effecting electronic integrated circuits have energies such that they deposit greater than 1 pC of charge, which is three orders of magnitude greater charge than is required for this architecture to sense the presence of incident ions. According to Table 2, when this second circuit configuration is set with “Q” node high and the “Q_BAR” node low, the node “Q_BAR” is sensitive to positive ions, while negative ions incident on node “Q_BAR” re-enforce the present state and would not record the presence of incident ions. In this second circuit configuration, the node “Q,” being set high, is highly resistant to both positive and negative ions, due to positive ions reinforcing the present state and negative ions requiring 36 million % greater energy, or 3.81 nC (six orders of magnitude greater deposited charge) to produce an unwanted state change or Single-Event-Upset. Therefore, the second circuit configuration, with “Q” node high and the “Q_BAR” node low, is optimized for use as a positive ion detector. Once the Single-Event-Upset has been detected by switching node “Q_BAR” from low to high, the circuit can be only changed back to it's original state by the system resetting it, or by having a negative ion striking “Q_BAR” with a minimum of 192 fC of deposited charge. An ion resetting the detector is unlikely. The reason it is unlikely for a negative ion to reset the second circuit configuration after it has been set by a Single-Event-Upset, by striking the node “Q_BAR” with a negatively charged ion, is the probability of a negatively charged ion hitting the same area as a positively charged ion, within the time-frame that the system checks for this event, is very highly improbable. The addition of a second similar circuit with the same bias conditions and monitored the same way, will virtually eliminate the possibility of the scenario of a negatively charged ion resetting the detector after it has been set by a positively charged ion, due to the probability of this scenario happening to two separate circuits during the same time period is practically infinite. The scenario of this second circuit configuration being used as a negative ion detector is substantially the same as it's use as a detector for positively charged ions as explained above, with the exception that the required deposited charge of an incident negative ion on node “Q_BAR” must be greater than or equal to 19.2 fC, which is roughly four time greater than is required for a positive ion to be sensed with the same circuit configuration. However this is not a concern since the average charge deposited by ions being sensed, is generally at least three orders of magnitude greater than the required charge deposition to activate this sensing circuit. The third circuit architecture, depicted in Table 2, the Peripheral SRAM having the Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 coupled to it, shows substantially the same operation as the second circuit architecture explained above, with the exception that the node “Q” is sensitized for sensing ionic activity whereas in the second circuit architecture the node “Q_BAR” was sensitized for sensing ionic activity. Since the Peripheral SRAM is symmetrical in design, the definition or notation of nodes “Q” and “Q_BAR” are irrelevant as long as they are defined within the system in which they are embedded. Third Embodiment FIG. 3 FIG. 3 is a block diagram of a peripheral bi-stable circuit in a Flip-Flop or Latch circuit configuration Peripheral FF/LATCH and a transistor level circuit diagram showing a Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C according to a third embodiment of this invention. The peripheral FF/LATCH circuit includes a first LOGIC GATE(S) LG 1 , a second LOGIC GATE(S) LG 2 , a first output terminal Q, and a second output terminal Q_BAR. The first LOGIC GATE(S) LG 1 having a first input IN 1 _ 1 coupled to the output terminal Q_BAR, zero (0) to “n” additional optional inputs, an output OUT 1 _ 1 coupled to the output terminal Q, and zero (0) to “m” additional optional outputs. The second LOGIC GATE(S) LG 2 having a first input IN 2 _ 1 coupled to the output terminal Q, zero (0) to “e” additional optional inputs, an output OUT 2 _ 1 coupled to the output terminal Q_BAR, and zero (0) to “f” additional optional outputs. The Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C includes a first Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 , a second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 , a first optional capacitor device control line Cont 1 , a second optional capacitor device control line Cont 2 , a first Bi-Directional Input/Output terminal Q, and a second Bi-Directional Input/Output terminal Q_BAR. The first Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 includes an N-type transistor device N 1 , a P-type transistor device P 1 , a capacitor device C 1 , a Common Source Terminal CS 1 , a high power supply node VD_N, and a low power supply node VD_P. The N-type transistor device N 1 having a drain type terminal coupled to the high power supply node VD_N, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and a source type terminal coupled to the Common Source Terminal CS 1 . The P-type transistor device P 1 having a drain type terminal coupled to the low power supply node VD_P, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and a source type terminal coupled to the Common Source Terminal CS 1 . The capacitor device C 1 having a first terminal coupled to the Common Source Terminal CS 1 , a second terminal coupled to the Bi-Directional Input/Output terminal Q, and an optional capacitor device control terminal coupled to Ccont 1 . The second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 includes an N-type transistor device N 2 , a P-type transistor device P 2 , a capacitor device C 2 , a Common Source Terminal CS 2 , a high power supply node VD_N, and a low power supply node VD_P. The N-type transistor device N 2 having a drain type terminal coupled to the high power supply node VD_N, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q, and a source type terminal coupled to the Common Source Terminal CS 2 . The P-type transistor device P 2 having a drain type terminal coupled to the low power supply node VD_P, a gate type terminal coupled to the Bi-Directional Input/Output terminal Q, and a source type terminal coupled to the Common Source Terminal CS 2 . The capacitor device C 2 having a first terminal coupled to the Common Source Terminal CS 2 , a second terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and an optional capacitor device control terminal coupled to Ccont 2 . The first and second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C_ 1 and 2T1C_ 2 are symmetrical and have components with identical aspect ratios and values. The operation of the first and second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C_ 1 and 2T1C_ 2 are substantially the same when either static or variable capacitors are use. The sizes of transistors will depend on the trans-conductance parameters of individual wafer foundries. The size of capacitors will depend on parameters of individual wafer foundries and the expected magnitude and duration of Single-Event-Effects. The capacitors need to retain enough charge, after the Single-Event-Effects have subsided, to “remember” the original state of the bi-stable circuit. The LOGIC GATE(S) LG 1 and LG 2 may take the form of inverters (as in the SRAM example in FIG. 2 ), AND gates, NAND gates, OR gates, NOR gates, Exclusive OR gates, Exclusive NOR gates, and multi-function gates, with the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C having substantially the same operation. The number of optional inputs and optional outputs of the LOGIC GATE(S) LG 1 and LG 2 is based on the composition of the internal logic of the LOGIC GATE(S) LG 1 and LG 2 . Operation Third Embodiment—FIG. 3 The operation of the circuit depicted in the block diagram of FIG. 3 , Peripheral FF/LATCH, is well known within the art. The operation of the circuit depicted in the block diagram of FIG. 3 , Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C, is substantially the same as the operation described for the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C in the FIRST EMBODIMENT. DETAILED DESCRIPTION Fourth Embodiment—FIG. 4 FIG. 4 is a block diagram of a peripheral bi-stable circuit in a Flip-Flop or Latch circuit configuration Peripheral FF/LATCH and a transistor level circuit diagram showing a Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C according to a fourth embodiment of this invention. The peripheral FF/LATCH circuit includes a first LOGIC GATE(S) LG 1 , a second LOGIC GATE(S) LG 2 , a first output terminal Q, and a second output terminal Q_BAR. The first LOGIC GATE(S) LG 1 having a first input IN 1 _ 1 coupled to the output terminal Q_BAR, zero (0) to “n” additional optional inputs, an output OUT 1 _ 1 coupled to the output terminal Q, and zero (0) to “m” additional optional outputs. The second LOGIC GATE(S) LG 2 having a first input IN 2 _ 1 coupled to the output terminal Q, zero (0) to “e” additional optional inputs, an output OUT 2 _ 1 coupled to the output terminal Q_BAR, and zero (0) to “f” additional optional outputs. The Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C includes a first Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 , a second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 , a first optional capacitor device control line Cont 1 , a second optional capacitor device control line Cont 2 , a first Bi-Directional Input/Output terminal Q, and a second Bi-Directional Input/Output terminal Q_BAR. The first Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 1 includes an N-type transistor device N 1 , a P-type transistor device P 1 , a capacitor device C 1 , a Common Emitter Terminal CE 1 , a high power supply node VD_N, and a low power supply node VD_P. The N-type transistor device N 1 having a collector type terminal coupled to the high power supply node VD_N, a base type terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and an emitter type terminal coupled to the Common Emitter Terminal CE 1 . The P-type transistor device P 1 having a collector type terminal coupled to the low power supply node VD_P, a base type terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and an emitter type terminal coupled to the Common Emitter Terminal CE 1 . The capacitor device C 1 having a first terminal coupled to the Common Emitter Terminal CE 1 , a second terminal coupled to the Bi-Directional Input/Output terminal Q, and an optional capacitor device control terminal coupled to Ccont 1 . The second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Device 2T1C_ 2 includes an N-type transistor device N 2 , a P-type transistor device P 2 , a capacitor device C 2 , a Common Emitter Terminal CE 2 , a high power supply node VD_N, and a low power supply node VD_P. The N-type transistor device N 2 having a collector type terminal coupled to the high power supply node VD_N, a base type terminal coupled to the Bi-Directional Input/Output terminal Q, and an emitter type terminal coupled to the Common Emitter Terminal CE 2 . The P-type transistor device P 2 having a collector type terminal coupled to the low power supply node VD_P, a base type terminal coupled to the Bi-Directional Input/Output terminal Q, and an emitter type terminal coupled to the Common Emitter Terminal CE 2 . The capacitor device C 2 having a first terminal coupled to the Common Emitter Terminal CE 2 , a second terminal coupled to the Bi-Directional Input/Output terminal Q_BAR, and an optional capacitor device control terminal coupled to Ccont 2 . The first and second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C_ 1 and 2T1C_ 2 are symmetrical and have components with identical aspect ratios and values. The operation of the first and second Two-Transistor One-Capacitor Radiation Single-Event-Effects Suppression Devices 2T1C_ 1 and 2T1C_ 2 are substantially the same when either static or variable capacitors are use. The sizes of transistors will depend on the trans-conductance parameters of individual wafer foundries. The size of capacitors will depend on parameters of individual wafer foundries and the expected magnitude and duration of Single-Event-Effects. The capacitors need to retain enough charge, after the Single-Event-Effects have subsided, to “remember” the original state of the bi-stable circuit. The LOGIC GATE(S) LG 1 and LG 2 may take the form of inverters (as in the SRAM example in FIG. 2 ), AND gates, NAND gates, OR gates, NOR gates, Exclusive OR gates, Exclusive NOR gates, and multi-function gates, with the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C having substantially the same operation. The number of optional inputs and optional outputs of the LOGIC GATE(S) LG 1 and LG 2 is based on the composition of the internal logic of the LOGIC GATE(S) LG 1 and LG 2 . Operation Fourth Embodiment—FIG. 4 The operation of the circuit depicted in the block diagram of FIG. 4 , Peripheral FF/LATCH, is well known within the art. The operation of the circuit depicted in the block diagram of FIG. 4 , Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C, is substantially the same as the operation described for the Four-Transistor Two-Capacitor Radiation Single-Event-Effects Suppression Device 4T2C in the FIRST EMBODIMENT. While certain preferred embodiments of the present invention have been disclosed and described herein for purposes of illustration and not for purposes of limitation, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

The present invention provides a Single-Event-Upset (SEU) and Single-Event-Gate-Rupture (SEGR) protection against incident radiation for any bi-stable circuit either in one state, having a 2 transistor, 1 capacitor integrated circuit coupled to a bi-stable circuit's outputs, or in both states, having a 4 transistor, 2 capacitor integrated circuit coupled to the bi-stable circuit's outputs. The protection against SEU and SEGR is achieved by the 2T1C or the 4T2C circuits, by providing the opposite drive to the SEU or SEGR event through capacitive coupling, and shunting electron-hole pair current, created by an ion tracking through the bi-stable circuit, into the power supplies. The 2T1C integrated circuit architecture, which only protects bi-stable circuits in one state, is to allow the bi-stable circuit to be a Single-Event-Upset (SEU) detector by capturing the effect of an incident ion and store that state. The 2T1C architecture, while protecting the bi-stable circuit after it has been affected by incident radiation, can alert the system the bi-stable integrated circuit is embedded in, to compensate or at be aware that an Single-Event-Upset has occurred. The purpose of the 4T2C integrated circuit architecture, which protects bi-stable circuits in both stable states, is to allow for critical data/state retention in any radiation environment, while not effecting speed of operation.

The present application claims the priority of U.S. Provisional Patent Application Ser. No. 60/928,206 filed 7 May, 2007, which application is incorporated in its entirety herein by reference. BACKGROUND OF THE INVENTION The present invention relates to stereo signal processing and in particular to processing a stereo signal to create the impression of a wide sound stage and/or of immersion. Conventional stereo reproduction, for example television, two-channel speakers such as iPod® speakers, etc., create an impression of a narrow spatial image. The narrow imaging is primarily due to loudspeaker proximity relative to each other and unmatched speaker-room frequency responses. The goal of any multichannel system is to give the listener an immersive or a “listener-is-there” impression. Unfortunately, narrow stereo imaging precludes such an experience. The spatial resolution (i.e., localization ability) of human hearing is at least one degree. It is desirable to manipulate stereo signals to enlarge the stereo sound field and imagery by combining concepts from physical acoustics (for example, room acoustics of the space the listener is located in), signal processing (for example, digital filtering), and auditory perception (for example, spatial localization cues). Stereo expansion will allow listeners to perceive audio signals arriving from a wider speaker separation with high-fidelity through the use of a unique binaural listening model and speaker-room equalization technique. Known stereo signal combining approach (for example, L+α(L−R) and R+α(R−L)) have attempted to expand the acoustic field. Unfortunately, these often result in vocals “drowned out” & midrange coloration. Also, benefits from speaker-room equalization cannot be incorporated because the stereo signal combining is independent of room equalization. Other methods include Head-Related-Transfer-Functions (HRTFs) premised on the localization ability of the human pinna (the visible portion of the ear extending from the side of the head which colors sound based on the arrival angle). However, human pinna vary among listeners and an expansion approach, involving use of specific direction HRTF, is not robust, and equalization is again defeated. BRIEF SUMMARY OF THE INVENTION The present invention addresses the above and other needs by providing a method for stereo expansion which includes a step to remove the effects of actual relative speaker to listener positioning and head shadow and a step to introduce an artificial effect based on a desired virtual relative speaker to listener positioning using the inter-aural delay and the head-shadow models for the virtual speakers at desired angles relative to the listener thereby creating the impression of a widened and centered sound stage and an immersive listening experience. Known methods drown out vocals and add mid-range coloration thereby defeating equalization. The present method includes the integration of a novel binaural listening model and speaker-room equalization techniques to provide widening while not defeating equalization. In accordance with one aspect of the invention, there is provided a method including determining speaker angles alpha and beta relative to a listener position wherein said speaker angles are computed using actual stereo speaker spacing and actual listener position, determining actual inter-aural delays between the speakers and the listeners ears, determining the headshadow responses associated with each ear relative to each of the speakers given the speaker angles equalizing the headshadow responses between the speakers and the listener ears, determining virtual speaker angles alpha′ and beta′ relative to listener position, determining virtual inter-aural delays between the speakers and the listeners ears for virtual speaker angles alpha′ and beta′, determining virtual headshadow responses associated with each ear relative to each of the virtual speakers given the virtual speaker angles, determining stereo expansion filters from the headshadow responses and the virtual headshadow responses, converting lattice form filters to shuffler form filters, variable octave complex smoothing the shuffler filters, and converting smoothed shuffler filters to smoothed lattice filters for performing spatialization and preserving the audio quality. In accordance with another aspect of the invention, there is provided a method including (a) determining actual speaker angles alpha and beta relative to listener position centered on the actual speakers wherein said speaker angles are computed using actual stereo speaker spacing and listener position, (b) determining actual inter-aural delays between the speakers and the listener ears, (c) determining the actual headshadow responses associated with each ear relative to each of the speakers given the speaker angles, (d) determining an actual speaker to listener 2×2 matrix transfer function H using the actual inter-aural delays and the actual headshadow responses, (f) determining virtual speaker angles alpha′ and beta′ relative to listener position wherein said virtual speaker angles are computed using a virtual stereo speaker spacing and listener position, (g) determining virtual inter-aural delays between the virtual speakers and the listeners ears for virtual speaker angles alpha′ and beta′ relative to listener position, (h) determining virtual headshadow responses associated with each ear relative to each of the virtual speakers given the virtual speaker angles and, (i) determining a virtual speaker to listener 2×2 matrix transfer function H desired representing the transfer functions between the virtual speakers and the listener ears, (j) selecting on-diagonal elements of H −1 H desired as a pair of ipsilateral filters and selecting off-diagonal elements of H −1 H desired as a pair of contralateral filters, (k) transforming the two pairs of ipsilateral filters and contralateral filters to a single pair of filters RES(1,1) and RES(2,2) to transform a lattice form to a shuffler form, (l) variable octave complex smoothing the pair of filters RES(1,1) and RES(2,2) to obtain smoothed filters sRES(111) and sRES(2,2) to preserve audio quality and spatial widening, and (m) transforming the pair of filters sRES(1,1) and sRES(2,2) back into lattice form for performing spatialization and preserving the audio quality. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: FIG. 1 shows an actual relative speaker to listener positioning and head shadow geometry. FIG. 2 shows head shadowing as a function of incidence angle. FIG. 3 shows a head shadow model. FIG. 4 shows a desired relative speaker to listener positioning for creating the impression of a widened and centered sound stage and an immersive listening experience according to the present invention. FIG. 5 is a wide synthesis stereo filter according to the present invention. FIG. 6 is a spatial equalization filter including widening and a phantom center channel shown in a lattice structure according to the present invention. FIG. 7 shows a visualization of relative speaker to listener positioning for creating the impression of a widened and arcing according to the present invention. FIG. 8 shows a shuffler filter representation of the present invention. FIG. 9A shows unsmoothed filter coefficients for RES(1,1) according to the present invention. FIG. 9B shows unsmoothed filter coefficients for RES(2,2) according to the present invention. FIG. 10A shows smoothed filter coefficients for sRES(1,1) according to the present invention. FIG. 10B shows smoothed filter coefficients for sRES(2,2) according to the present invention. FIG. 11 describes a method according to the present invention. Corresponding reference characters indicate corresponding components throughout the several views of the drawings. DETAILED DESCRIPTION OF THE INVENTION The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims. Left and right speakers (or transduces) 10 L and 10 R and a listener 12 are shown in FIG. 1 . The speakers 10 L and 10 R receive left and right channel signals X L and X R and have a speaker spacing d T . Speaker response measurements may be obtained at a listener position 12 a centered on the listener head 12 through two channels h L,C and h R,C . Signals Y L and Y R at listener ear positions 11 L and 11 R are determined based on direct sound based binaural response modeling because localization is governed primarily through direct sound. The distances d L,C and d R,C from left speaker 10 L and from the right speaker 10 R respectively to a microphone centered at the listener position 12 a , may be obtained from existing technique (for example, a sample in the first peak in the responses h L,C and h R,C ) or setting the distances to nominal values. Speaker angles α and β (where a 90 degree speaker angle is directly in front of the listener) may be computed as: α = cos - 1 ( d L , C 2 + d T 2 + d R , C 2 2 ⁢ d L , C ⁢ d T ) β = cos - 1 ( d R , C 2 + d T 2 + d L , C 2 2 ⁢ d R , C ⁢ d T ) The signals Y L and Y R at each ear position 11 L and 11 R may be represented in terms of the propagation delays and the effects of head shadowing (diffraction or attenuation effects) relative to the responses h L,C =δ L,C and h R,C =δ R,C (acoustic direct path propagation responses) at the listener position 12 a from left and right speakers 10 L and 10 R respectively. The listener 12 is assumed to have a head radius a of approximately nine centimeters, an ear offset γ of approximately ten degrees, and the system to have a sampling frequency of f s . Four headshadowed responses result: 1) A headshadowed response H α+γ L,L (z) results from an observation point being the left ear position 11 L for signals arriving from the left channel (i.e., the angle of the incident wave relative to the left ear position 11 L is α+γ); 2) A headshadowed response H π−β+γ R,L (z) results from an observation point being the left ear position 11 L for signals arriving from the right channel (i.e., the angle of the incident wave relative to the left ear position 11 L is π−β+γ); 3) A headshadowed response H π−α+γ L,R (z) results from an observation point being the right ear position 11 R for signals arriving from the left channel (i.e., the angle of the incident wave relative to the right ear position 11 R is π−α+γ); and 4) A headshadowed response H β+γ R,R (z) results from an observation point being the right ear position 11 R for signals arriving from the right channel (i.e., the angle of the incident wave relative to the right ear position 11 R is β+γ). The signals at each ear position 11 L and 11 R may then be calculated as a function of the headshadowed response as: Y L ⁡ ( z ) = z ⌊ ψ ⁢ ⁢ L , L ⌋ ⁢ H L , C ⁡ ( z ) ⁢  H α + γ L , L ⁡ ( z )  ⁢ X L ⁡ ( z ) + z ⌊ ψ ⁢ ⁢ R , L ⌋ ⁢ H R , C ⁡ ( z ) ⁢  H π - β + γ L , R ⁡ ( z )  ⁢ X R ⁡ ( z ) Y R ⁡ ( z ) = z ⌊ ψ ⁢ ⁢ L , R ⌋ ⁢ H L , C ⁡ ( z ) ⁢  H π - α + γ L , R ⁡ ( z )  ⁢ X L ⁡ ( z ) + z ⌊ ψ ⁢ ⁢ R , R ⌋ ⁢ H R , C ⁡ ( z ) ⁢  H β + γ R , R ⁡ ( z )  ⁢ X R ⁡ ( z ) H L , C = H R , C = 1 where: ψ L , L = { a ⁢ ⁢ cos ⁡ ( α + γ ) ⁢ f s c 0 < α ≤ π 2 - γ - a ⁢ ⁢ cos ⁡ ( α - π 2 + γ ) ⁢ f s c π 2 - γ < α ≤ π 2 ⁢ ⁢ ψ R , R = { a ⁢ ⁢ cos ⁡ ( β + γ ) ⁢ f s c 0 < β ≤ π 2 - γ - a ⁢ ⁢ cos ⁡ ( β - π 2 + γ ) ⁢ f s c π 2 - γ < β ≤ π 2 ⁢ ⁢ ψ R , L = { - a ⁢ ⁢ cos ⁡ ( π 2 - β + γ ) ⁢ f s c 0 < β ≤ π 2 - γ - a ⁢ ⁢ cos ⁡ ( π 2 - β + γ ) ⁢ f s c π 2 - γ < β ≤ π 2 ⁢ ⁢ and , ⁢ ψ L , R = { - a ⁢ ⁢ cos ⁡ ( π 2 - α + γ ) ⁢ f s c 0 < α ≤ π 2 - γ - a ⁢ ⁢ cos ⁡ ( π 2 - α + γ ) ⁢ f s c π 2 - γ < α ≤ π 2 where ψ X,Y is the actual inter-aural delay between speaker X and ear Y, a is head radius, fs is sample frequency, and c is sound speed. H L,C and H R,C are speaker to center of head transfer function matrices and are assumed to be unity here. The headshadowed models used are range independent. Accuracy may potentially be improved by multiplying by a distance or (room-dependent factor such as D/R) with H θ (ω) as shown in FIG. 2 . The headshadowed model H θ (ω) may be approximated by a single pole filter Ĥ θ (ω) shown in FIG. 3 for θ=0 degree (curve 14 ), θ=45 degree (curve 16 ), θ=90 degree (curve 18 ), θ=120 degree (curve 28 ), and θ=150 degree (curve 22 ), applied for f>1.5 kHz: H ^ θ ⁡ ( ω ) = 1 + j ⁢ ⁢ τ θ ⁢ ω 2 ⁢ ω 0 1 + j ⁢ ⁢ ω 2 ⁢ ω 0 τ θ = ( 1 + τ min 2 ) + ( 1 + τ min 2 ) ⁢ ⁢ cos ( θ θ min ⁢ 180 ) τ min = 0.1 θ min = 150 The signals Y L and Y R at each ear may then be represented in matrix form as: [ Y L Y R ] = H ⁡ [ X L X R ] where the actual speaker to listener matrix transfer function H, including both inter-aural delays and headshadow responses, is: H = [ z ψ ⁢ ⁢ L , L ⁢ H ^ α + γ L , L ⁡ ( z ) z ψ ⁢ ⁢ R , L ⁢ H ^ π - β + γ R , L ⁡ ( z ) z ψ ⁢ ⁢ L , R ⁢ H ^ π - α + γ L , R ⁡ ( z ) z ψ ⁢ ⁢ R , R ⁢ H ^ β + γ R , R ⁡ ( z ) ] where the headshadow models Ĥ θ (ω) may be minimum phase. Additionally, an equalization filter matrix G(z) may be designed to counteract the effects of “regular” stereo perception using a joint minimum-phase approach disclosed in “An Alternative Design for Multichannel and Multiple Listener Room Equalization” S. Bharitkar, Proc. 2004 38 th IEEE Asilomar Conference on Signal, Systems, and Computers, Pacific Grove, Calif., November 2004 to minimize artifacts: [ Y L Y R ] = HG ⁡ [ X L X R ] and when G(z) is formed as H −1 (z): [ Y L Y R ] = [ X L X R ] A wide stereo synthesis visualization 24 according to the present invention is shown in FIG. 4 . A left synthesized (or virtual) speaker 10 L′ is shown displaced a distance p 1 to the left of the speaker 10 L, and a right synthesized (or virtual) speaker 10 R′ is shown displaced a distance p 2 to the right of the speaker 10 L. Given p 1 and/or P 2 , the distances d L,C ′ and d R,C ′ from the synthesized speakers to the microphone position are computed as: d L,C ′=√{square root over (( p 1 +d L,C cos α) 2 +( d L,C sin α) 2 )}{square root over (( p 1 +d L,C cos α) 2 +( d L,C sin α) 2 )} d R,C ′=√{square root over (( p 2 +d R,C cos β) 2 +( d L,C sin α) 2 )}{square root over (( p 2 +d R,C cos β) 2 +( d L,C sin α) 2 )} Virtual speaker angles α′ and β′ are computed: tan ⁢ ⁢ α ′ = d L , C ⁢ sin ⁢ ⁢ α p 1 + d L , C ⁢ cos ⁢ ⁢ α and tan ⁢ ⁢ β ′ = d L , C ⁢ sin ⁢ ⁢ α p 2 + d R , C ⁢ cos ⁢ ⁢ β It is generally (but not necessarily) desired that the listener 12 perceives themself to be centered on the speakers 10 L′ and 10 R′. In order to achieve the centered perception, the virtual speaker angles α′ and β′ should be perceived as being approximately equal, which is equivalent to: p 1 +d L,C cos α= p 2 +d R,C cos β The desired left and right signals Y L ′ and Y R ′ at the listener ear positions 11 L and 11 R in matrix representation are: [ Y L Y R ] = H desired ⁡ [ X L X R ] where a speaker to listener matrix transfer function H desired is determined from the virtual inter-aural delays Δ X,Y and the virtual headshadow responses: H desired = [ z Δ L , L ⁢  H ^ α ′ + γ L , L ⁡ ( z )  z Δ R , L ⁢  H ^ π - β ′ + γ R , L ⁡ ( z )  z Δ L , R ⁢  H ^ π - α ′ + γ L , R ⁡ ( z )  z Δ R , R ⁢  H ^ β ′ + γ R , R ⁡ ( z )  ] Virtual inter-aural delays Δ L,L , Δ R,R , Δ L,R , and Δ R,L based in the positions of the virtual speakers 10 L′ and 10 R′ and incorporated in left and right channels h L,C and h R,C , are: Δ L , L = ⌊ ( - d L , C ′ + δ L , L ) ⁢ f s c ⌋ Δ R , R = ⌊ ( - d R , C ′ + δ R , R ) ⁢ f s c ⌋ where , ⁢ δ L . L = { a ⁢ ⁢ cos ⁡ ( α ′ + γ ) 0 < α ′ ≤ π 2 - γ - a ⁢ ⁢ cos ⁡ ( α ′ - π 2 + γ ) π 2 - γ < α ′ ≤ π 2 ⁢ ⁢ δ R , R = { a ⁢ ⁢ cos ⁡ ( β ′ + γ ) 0 < β ′ ≤ π 2 - γ - a ⁢ ⁢ cos ⁡ ( β ′ - π 2 + γ ) π 2 - γ < β ′ ≤ π 2 ⁢ ⁢ and ⁢ ⁢ Δ R , L = ⌊ ( - d R , C ′ + δ R , L ) ⁢ f s c ⌋ ⁢ ⁢ Δ L , R = ⌊ ( - d L , C ′ + δ L , R ) ⁢ f s c ⌋ ⁢ ⁢ where , ⁢ δ RL = { - a ⁡ ( π 2 - β ′ + γ ) 0 < β ′ ≤ π 2 - γ - a ⁡ ( π 2 - β ′ + γ ) π 2 - γ < β ′ ≤ π 2 ⁢ ⁢ δ L , R = { - a ⁡ ( π 2 - α ′ + γ ) 0 < α ′ ≤ π 2 - γ - a ⁡ ( π 2 - α ′ + γ ) π 2 - γ < α ′ ≤ π 2 and where the virtual inter-aural delays Δ X,Y are in units of samples. A wide synthesis stereo filter 25 according to the present invention and corresponding to the visualization of FIG. 4 is shown in FIG. 5 . The filters 26 , 28 , 30 , and 32 represent the elements of H desired and serve to create the desired wide stereo perception. The equalization filter G(z) 38 receives the summed outputs of the filters 26 and 30 , and 38 and 32 , summed at 34 and 36 respectively and serves to reduce or eliminate the effects of regular stereo perception. Surround synthesis may be obtained by substituting -γ for γ to obtained: Δ L , L = ⌊ ( - d L , C ′ + δ L , L ) ⁢ f s c ⌋ Δ R , R = ⌊ ( - d R , C ′ + δ R , R ) ⁢ f s c ⌋ where , ⁢ δ L . L = a ⁢ ⁢ cos ⁡ ( α ′ - γ ) 0 < α ′ ≤ π 2 δ R , R = a ⁢ ⁢ cos ⁡ ( β ′ - γ ) ⁢ 0 < β ′ ≤ π 2 and Δ R , L = ⌊ ( - d R , C ′ + δ R , L ) ⁢ f s c ⌋ Δ L , R = ⌊ ( - d L , C ′ + δ L , R ) ⁢ f s c ⌋ where , ⁢ δ RL = - a ⁡ ( π 2 - β ′ - γ ) 0 < β ′ ≤ π 2 ⁢ δ L , R = - a ⁡ ( π 2 - α ′ - γ ) 0 < α ′ ≤ π 2 ⁢ A phantom center channel filter 39 according to the present invention providing widening along with generating a phantom center is shown in a lattice structure in FIG. 6 . A pair of ipsilateral filters 42 and 48 and a pair of contralateral filters 44 and 46 may be determined from the 2×2 matrix G*H desired , where G includes H −1 . G and H desired are computed as described above. In the general case, the pair of ipsilateral filters 42 and 48 are the diagonal terms of G*H desired , and the contralateral filters 44 and 46 are the off-diagonal terms of G*H desired . In special cases where the listener 12 is centered on the speakers 10 L and 10 R, the two diagonal terms are equal and the two off diagonal terms are equal so that the ipsilateral filters 42 and 48 may be obtained from the first row and first column of the frequency response matrix G*H desired and the contralateral filters 44 and 46 may be obtained from the first row and second column of the frequency response matrix G*H desired . The matrix G*H desired is computed at various frequency values and the inverse Fourier transform is taken to obtain the ipsilateral filters 42 and 48 and the contralateral filters 44 and 46 in the time domain. The matrix G*H desired is a 2×2 matrix for each frequency point. If there are 512 frequency points we obtain 512 matrices of 2×2 size. In the listener centered case, only the element in the first row and first column from each of the 512 2×2 matrices is taken to form a frequency response vector for the ipsilateral filters 42 and 48 . The frequency response vector is inverse Fourier transformed to obtain the ipsilateral time domain filters 42 and 48 . The process is repeated to obtain the contralateral filters 44 and 46 but selecting the element in the first row and second column. A second equalization filter G′ 40 , 50 provides the phantom center. The phantom center channel filter 39 may process either the inputs to a room equalizer or process the outputs of the room equalizer. The method of the present invention may further be expanded to provide a perception of arcing. An arced stereo synthesis visualization 55 according to the present invention is shown in FIG. 7 . A desired relative speaker to listener positioning for creating the impression of a widened and arcing according to the present invention is provided by a second left synthesized (or virtual) speaker 10 L″ shown displaced a distance p 1 to the left and δp 1 ahead of the speaker 10 L, and a second right synthesized (or virtual) speaker 10 R″ shown displaced a distance p 2 to the right and δp 2 ahead of the speaker 10 L. The following equations result: Λ = tan - 1 ( δ p ⁢ ⁢ 1 p 1 ) z 2 = p 1 2 + δ p 1 Ω = π - Λ - α d LW , C 2 = d L , C 2 + z 2 - 2 ⁢ zd L , C ⁢ cos ⁢ ⁢ Ω Δ = cos - 1 ( z 2 + d LW , C 2 - d L , C 2 2 ⁢ zd LW , C ) α ′ = Δ - Λ where these terms may be substituted into the above equations for computing the inter-aural delays Δ X,Y obtain widening and arcing according to the present invention. The methods of the present invention may further be expanded to include where: the binaural modeled equalization matrix G(z) is lower order modeled with existing techniques; simple delays and shadowing filters (one poll) are implemented; the stereo-expansion system compensates for speaker room effects simultaneously; multi-position and robustness is obtained with least-squares based binaural equalization filter matrix G(z), spatial derivatives/difference constraints etc. speech—music discrimination for center channel synthesis with PC=−d T /2 and/or integrating with X L +X R approach; potential to pre-integrated with PrevEQ by using head diffraction model engaged beyond 1.5 kHz (that is, intensity differences) with speaker only response; using all pass filters with group delays T 1 f<1.5 kHz =c 1 and T 2 f>1.5 kHz =c 2 for Δ L,R (Δ R,L ); torso modeling; and distance or room-based function multiplying head-diffraction model. The lattice form can be transformed to the shuffler form (as in Bauck et al, “Prospects of Transaural Recording,” Journal of Audio Eng. Soc., vol. 37 (1/2), January/February 1989). For example, assuming a 2×2 matrix X having elements S and A: X = [ S A A S ] where S is the ipsilateral transfer function and A is the contralateral function The inverse Y of X is: Y = X - 1 = 1 S 2 - A 2 ⁡ [ S - A - A S ] and Y can be factored using eigenvalue/eigenvector decomposition as: Y = [ 1 1 1 - 1 ] ⁡ [ 1 2 ⁢ ( S + A ) 0 0 1 2 ⁢ ( S - A ) ] ⁡ [ 1 1 1 - 1 ] Note, in this form there are only two filters (i.e., 1/(2(S+A)) and 1/(2(S−A)) located diagonally instead of four filters. The closer these are to a value unity, the net transfer function Y since Y=[1 0;0 1] becomes relatively lossless at all frequencies which implies no distortion or artifacts. In this case the output as Y=[2 0;0 2] which implies YL=2*XL and YR=2*XR (i.e., the left channel is transmitted to the output simply gain changed by a factor of 2 and the right channel is transmitted to the output gain changed by a factor of 2). Incorporating this concept into the present system, the inverse G=H^ (−1) may be multiplied with H desired and factored into shuffler form as: RES =G*H desired =H^ (−1) *H desired =Y*H desired with H desired being represented as H desired =[L M;M L] where L and M are the desired ipsilateral and contralateral transfer functions (i.e., including the inter-aural delays and headshadow responses). Thus the resulting filters in lattice form can be expressed as: RES = ⁢ ( 1 / ( S ^ ( 2 ) - A ^ ( 2 ) ) ⁡ [ S - A ; - A ⁢ ⁢ S ] ⁡ [ L ⁢ ⁢ M ; M ⁢ ⁢ L ] = ⁢ ( 1 / ( S ^ ( 2 ) - A ^ ( 2 ) ) [ SL - AM ⁢ ⁢ SM - AL ; ⁢ SM - AL ⁢ ⁢ SL - AM ] The above may be factored using eigen decomposition into: RES = ⁢ [ RES ⁡ ( 1 , 1 ) ⁢ ⁢ 0 ; 0 ⁢ ⁢ RES ⁡ ( 2 , 2 ) ] = ⁢ [ 1 ⁢ ⁢ 1 ; 1 - 1 ] [ ( L + M ) / 2 * ( S + A ) ⁢ ⁢ 0 ; ⁢ 0 ⁢ ⁢ ( L - M ) / 2 * ( S - A ) ] ⁡ [ 1 ⁢ ⁢ 1 ; 1 - 1 ] The resulting shuffler filter is shown in FIG. 8 where the two filters RES(1,1) 62 and RES(2,2) 64 , one in each channel, are transformed from the lattice structure of FIG. 6 . The sum 58 of signals XL and XR is provided to RES(1,1) and the difference 60 of signal XR−XL is provided to RES(2,2) 64 . The signal XL is provided to the phantom gain G′ 68 and the signal XR is provided to the phantom gain G′ 70 . The difference 72 of the output of G′ 68 plus RES(1,1) 62 minus RES(2,2) 64 is output as YL and the sum 74 of the output of G′ 70 plus RES(1,1) 62 plus RES(2,2) 64 is output as YL. Examples of unsmoothed filters RES(1,1) and RES(2,2) are shown before smoothing in FIGS. 9A and 9B . Smoother filters sRES(1,1) and sRES(2,2) are shown after complex smoothed (joint magnitude and phase) using a variable-octave complex smoother to remove unwanted temporal (magnitude and phase) variations that result in artifacts in the reproduced sound quality in FIGS. 10A and 10B . In this example, the smoothing is 4 octave wide smoothing to remove unnecessary temporal variations so as to approximate a Kronecker delta function. This feature, in essence, provides a tradeoff between amount of spatialization and audio fidelity. The variable-octave complex smoothing allows high-resolution frequency smoothing in regions of the frequency response of the filter by retaining perceptual features in the frequency response of each of the filters which are dominant for accurate localization, while at the same time performing temporal smoothing to allow each filter to converge to a delta function such that RES matrix is close to [1 0;0 1] at each frequency bin for maintaining audio fidelity. The variable-octave complex-domain smoother is described in “Variable-Active Complex Smoothing for Loudspeaker-room Response Equalization” published in Proceedings of IEEE International Conference Consumer Electronics, Las Vegas Nev., January 2008, authored by S. Bharitkar, C. Kyriaskakis, and T. Holman. For example, a complex-domain ⅓ octave full-band (0 Hz to Fs/2 where Fs=sampling frequency in Hz) smoothing may be performed, or 2-octaves wide full-band smoothing may be performed, or 1/12 th -octave smoothing between 1 kHz and 10 kHz may be performed (as the headshadow functions of FIG. 2 show variations in this region) and 2-octave complex (joint magnitude and phase) smoothing may be performed in the other region (viz., [0 Hz, 1 kHz)U(10 kHz, Fs/2)). Subsequently, the smoothed filters sRES are transformed back into the lattice form of FIG. 6 by the following transformation (where sRES(x,x) is the corresponding smoothed filter of the shuffler form RES(x,x)). The resulting filters are: ⁢ = ⁢ [ 1 ⁢ ⁢ 1 ; 1 - 1 ] ⁡ [ sRES ⁡ ( 1 , 1 ) ⁢ ⁢ 0 ; 0 ⁢ ⁢ sRES ⁡ ( 2 , 2 ) ] ⁡ [ 1 ⁢ ⁢ 1 ; 1 - 1 ] = ⁢ [ sRES ⁡ ( 1 , 1 ) + sRES ⁡ ( 2 , 2 ) ⁢ ⁢ sRES ⁡ ( 1 , 1 ) - sRES ⁡ ( 2 , 2 ) ; ⁢ sRES ⁡ ( 1 , 1 ) - sRES ⁡ ( 2 , 2 ) ⁢ ⁢ sRES ⁡ ( 1 , 1 ) + sRES ⁡ ( 2 , 2 ) ] A method for providing a stereo-widened sound in a stereo speaker system is described in FIG. 11 . The method includes determining speaker angles alpha and beta relative to a listener position wherein said speaker angles are computed using stereo speaker spacing and listener position at step 100 , determining inter-aural delays between the speakers and the listeners ears at step 102 , determining the headshadow responses associated with each ear relative to each of the speakers given the speaker angles at step 104 , equalizing the headshadow responses between the speakers and the listener ears at step 106 , determining virtual speaker angles alpha′ and beta′ relative to listener position at step 108 , determining virtual inter-aural delays between the speakers and the listeners ears for virtual speaker angles alpha′ and beta′ at step 110 , determining virtual headshadow responses associated with each ear relative to each of the virtual speakers given the virtual speaker angles at step 112 , determining stereo expansion filters from the headshadow responses and the virtual headshadow responses at step 114 , converting lattice form filters to shuffler form filters at step 116 , variable octave complex smoothing the shuffler filters at step 118 , and converting smoothed shuffler filters to smoothed lattice filters for performing spatialization and preserving the audio quality. While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.

A method for stereo expansion includes a step to remove the effects of actual relative speaker to listener positioning and head shadow and a step to introduce an artificial effect based on a desired virtual relative speaker to listener positioning using the inter-aural delay and the head-shadow models for the virtual speakers at desired angles relative to the listener thereby creating the impression of a widened and centered sound stage and an immersive listening experience. Known methods drown out vocals and add mid-range coloration thereby defeating equalization. The present method includes the integration of a novel binaural listening model and speaker-room equalization techniques to provide widening while not defeating equalization.

FIELD OF THE INVENTION The present invention relates to an apparatus and method for depositing particulate food items. BACKGROUND OF THE INVENTION There has long been a need in the baking industry for a depositor which will uniformly distribute particulates, particularly raisins. Distribution should be uniform both in weight per time and across the material onto which the particulates are deposited, for example, a dough sheet. With particular reference to raisins, raisins have been problematic in their depositing. Three types of depositors have been used, those are vibratory feeders, for example, those made by Sintrum Co., screw feeders, for example, those made by Moline, paste spreaders and oscillating screens. These types of feeders have required that the raisins first be washed and then coated with a dry powder material to reduce stickiness. Even with such additional expensive and time-consuming processing, these types of feeders have been irregular or non-uniform in depositing and have caused damage to the raisins which are relatively soft and easily damaged by cutting or mashing. If the raisins are not pre-processed prior to distribution, the problems of distribution and damage are worse. It has long been a desire in the baking industry to be able to accurately deposit raisins and other food particulates accurately and without damage to them. The present invention provides means for depositing in a simple and inexpensive manner, from a machine standpoint, and also reduces the need for pre-processing of sticky particulates such as raisins. It was found that when using the present invention that raisins need only be washed prior to depositing and that the depositing with the present invention provided more uniform distribution both by weight per unit of time and uniformity across the width of the material being deposited upon. In the baking industry either a sheet of dough or dough pre-forms, for example, pre-formed rolls, have raisins deposited thereon as they move under a depositor. A dough sheet with deposited raisins can be further processed, for example, laminated, and then formed into pre-forms for subsequent cooking. The pre-forms with raisins thereon are typically ready for cooking after the depositing. Further, particulates can be deposited on a bakery item after the bakery item is cooked. Because of the variety of positions at which the depositing can take place, it has long been a desire to provide a depositor that was easily portable to various positions on the processing line. The present invention also solves this problem. Surprisingly, it was found that the present invention not only worked well with soft particulates, for example, raisins, but that it was also effective with numerous other particulate materials, for example, hard particulates like nutmeats or nutmeat portions, fragile particulates, for example, sliced almonds and streusel and non-uniformly sized particulates. The invention can also be used on fine particulates, for example, flours and cereal-grained meals and sugar. It is an object of the present invention to provide a depositor which will uniformly deposit soft particulates like raisins. It is another object of the present invention to provide a depositor which will handle a large variety of particulate materials. It is another object of the present invention to provide a depositor which will handle fragile or easily damaged particulates with minimal damage thereto during depositing. It is another object of the present invention to provide a depositor which is easily changed to accommodate different materials. It is another object of the present invention to provide a depositor which is portable and adapted for movement to various positions on a processing line. It is a still further object of the present invention to provide a depositor which overcomes the above discussed problems in the baking industry. It is a still further object of the present invention to provide a depositor which is simple in construction and easy to manufacture and maintain. FIGURES FIG. 1 is a side elevation view of the depositor. FIG. 2 is a side elevation view of the drive means. FIG. 3 is a sectional view along line 3--3 of FIG. 1. FIG. 4 is an end elevational section taken along the line 4--4 of FIG. 1. FIG. 5 is a schematic diagram of the air control system for the drive means. FIG. 6 is a schematic diagram of the electrical control system. DETAILED DESCRIPTION The reference number 1 designates generally a particular depositor which includes a support framework 2 having mounted thereon hopper means 3. The reference numeral 4 designates generally the drive means which is operable for driving portions of the hopper feed means 3. The support framework is generally U-shaped comprising bottom framework 6 having mounted thereon wheels 7. Secured to the bottom 6 is an upstanding frame portion 8 which has mounted thereon the drive means 4. A top frame member 9 is secured to the upstanding frame 8 and has the hopper feed means 3 mounted thereon. By being U-shaped, the depositor 1 can be easily moved into position on a processing line permitting the bottom frame to be positioned beneath a portion of the line and the top frame is positioned above the processing line. When the depositor is used for food depositing, it is preferred that all the materials be acceptable for use in a food plant and is typically stainless steel. The hopper feed means 3 includes an elongate hopper comprising side wall members 11 and 12 and end wall members 13 and 14. The end walls are generally parallel. The side walls can assume any desired shape and dimensions and preferably are shaped so as to prevent bridging and plugging during operation of the depositor. In the particular form shown, the side walls have upper portions 15 and 16 which are both angled relative to vertical with the included angle therebetween being in the range of between about 25° and about 40° total included angle. It has been found particularly desirable for raisins to have an included angle of approximately 36°. The end walls 13 and 14 and the side walls 11 and 12 are secured together in any suitable manner, as for example, by welding. A perforate or screen member 20 is suitably removably mounted on the hopper 3. Preferably, the screen 20 is mounted in a manner such that it can be easily removed for cleaning or changing. It is preferred that the screen have a round contour in cross section and it should generally match the contour of the lower positioned screw 21. The screen extends the length of the side walls 11 and 12 and is mounted thereon by hinges 22 and is secured in position by toggle latches 23. Preferably, the hinges 22 are of a kind that includes a pin 24 mounted on the side wall 11 and the screen 20 has slotted members 25 secured thereto such that after a certain amount of rotation thereof the hinge slot is in a position that the slotted member 25 can be disengaged from the pins 24. It is preferred that the screen be imperforate at each end for a length approximately equal to one flight of the lower screw 21, to provide a non-feed area for the particulate material in the hopper 3. Secured to the top frame 9 are support bars 26 and 27 which are positioned under the hopper means 3 and form a grid. It is desired to provide a deflector 28 which is generally V-shaped and extends the approximate length of the side walls 11 and 12. In operation, deflector 28 has the apex of the V pointing upwardly providing a diverging deflector with respect to particulate movement downwardly thereover. It has been found that the deflector helps provide uniformity of distribution of the particulates and also functions as an accumulator reducing the effect of the dead time during the reversal of the rotation oscillation of the screws in the hopper means 3. The deflector 28 can be loosely positioned under the hopper or can be permanently affixed thereunder. In a preferred embodiment of the present invention, the plurality of screws are mounted in the hopper feed means 3. As shown, two screws in superposed relation are provided. The screws 21 and 30 are suitably rotatably mounted in the hopper means 3, as for example, by bearings 31 secured to the end walls 13 and 14. The screws 21 and 30 are generally parallel to the side walls 11 and 12 with the lower screw 21 being positioned between the lower portions of the side walls 11 and 12 while the upper screw is mounted thereabove and being in superposed relation. The axis of the screw 30 is generally vertically above the axis of the screw 21. As shown the lower screw 21 can have a plurality of radially projecting pins 32, e.g., between every flight and extending in generally radially opposite directions. If desired both screws can have pins 32. The pins help break up materials that tend to clump together. For food products, it has been found particularly desirable to have the lower screw with an outside diameter in the range of between about one inch and about four inches. For raisins, it has found particularly good to have this diameter at two inches. It is preferred that the upper screw 30 be larger than the lower screw 21. Desirably, the upper screw 30 diameter should be in the range of between about 2 and about 5 inches. It is particularly desirable for depositing raisins that the upper screw 30 diameter be approximately 4 inches. Preferably, the diameter ratio of the lower screw 21 to the upper screw 30 is in the range of between about 1:1 and about 1:3. It is particularly desirable to have the screw diameter ratio of 1:2 for the depositing of raisins. As seen in the figures, there is a gap between the outer diameter of each of the screws and sidewalls and between the shafts 33 and 34 of the screws 21 and 30, respectively, and their respective side walls of the hopper. It is preferred that with the lower screw 21 that the gap A between the shaft and the wall be in the range of between about 1/4 inch and about one inch with a preferred spacing for raisins being 3/4 inch. For the upper screw 30, the gap B is preferred to be in the range of between about 3/4 inch and about 11/2 inch with a preferred gap B for raisins being 11/4 inch. It is also preferred that the ratio of the gap A to B be in the range of about 1:1 to about 1:2. Depending upon the particular type of material being deposited, the gap C and D between the screw flights and the side walls be in the range of between about 1/16 inch and about 1/2 inch and more preferably in the range of between about 1/8 inch and about 1/4 inch. In general, the smaller the particulate, the smaller the gap one can use without damaging the particulates during depositing. Also, depending upon the type of particulates being deposited, the screws 21 and 30 have a pitch in the range of between about one inch and about four inches and preferably for the depositing of raisins, the pitch is two inches. Also, it is preferred that during operation, that both screws 21 and 30, rotate simultaneously in the same direction and that the pitch also be in the same direction. However, other ranges can also be used. The screws 21 and 30 can have a length up to 60 inches or even more to provide depositing over very long distances. It is preferred that the side walls 11 and 12 be sufficiently high to provide a head over the top of the upper screw 30 in excess of four inches and for foods it is desired that the head be less than about 14 inches. Higher walls for the hopper could be provided so long as the head of material contained in the hopper is maintained within appropriate ranges. With regard to the screen 20, the size and shape of the openings 36 will be dependent upon the material to be deposited. Preferably, the holes are round and have a diameter in the range of between about 1/8 inch and about one inch. It has been found that numerous materials can be accurately deposited with 1/2 inch diameter openings. The drive means can be any suitable drive means effective to suitably drive the screws 21 and 30. In a preferred embodiment, the screws 21 and 30 simultaneously rotate in the same direction and oscillate or reverse direction at pre-selected intervals of rotation. Continuous rotation of the screws in one direction tends to damage the product. In the form of the invention shown, the drive means 4 includes a drive actuator 38 which is connected through suitable drive means to each of the screws 21 and 30 to effect their rotation. As shown, the drive actuator is a rotary actuator which is an air cylinder 39 with a rack and pinion drive connected to an output shaft in one direction of travel of the cylinder, the shaft rotates in one direction and on reverse movement of the cylinder, the shaft rotates in the opposite direction. The drive actuator 38 is connected to the screws 21 and 30 by a shaft 41. The shaft 41 has mounted thereon a sprocket which in turn is connected to the shafts of the screws 21 and 30 via sprockets 42 and a chain 43. In the form shown, operation of the drive actuator 38 rotates both shafts simultaneously in the same direction, both in forward and reverse directions. Speed of the drive actuator and hence the rotational speed of the screws 21 and 30, can be controlled as is known in the art by restricting the exhaust ports of the cylinder 39. In the illustrated form of the invention, this can be simultaneously accomplished by having a respective control valve 70 or 71 connected to each of the exhaust ports of the cylinder 39. The valves 70 and 71 can be connected together via sprockets and a chain 45 and 46, respectively. By having the valves 44 variable, restriction is also variable and therefore the operating speed of the cylinder 39. It is preferred that the rotational speeds of the screws be in the range of between about 20 rpm and about 200 rpm and preferably in the range of between about 40 rpm to about 140 rpm. The lower screw 21 and screen member 20 cooperate in a manner such that particulates are fed or deposited along the length thereof and not from the end of the screw as in typical screw feeders. The drive means further includes control means for effecting rotational reversal and as shown, that includes cam members 48 and 49 mounted on the shaft 41. During rotation, the cam members actuate limit switches 50 and 51, respectively, which in turn control the solenoid valve 67. For foods, it is believed that no more than about three revolutions of the screws 21 and 30 should be made before reversal. It has been found particularly desirable to have the screws rotate approximately one revolution before reversing. Although not shown, it is to be understood that the drive actuator 38 can be timed for on/off sequencing for spot depositing rather than continuous depositing. Further, funnel members can be placed underneath the screen 20 to have the particulates deposited in multiple strips rather than one continuous curtain across the width of the hopper. The two above can be combined for spot depositing in multiple strips. In order to provide safe operation, the depositor 1 can be provided with guards 52 and 53 at the depositing area. Microswitches 54 are mounted on the depositor 1 and are operative to electrically show that the guards 52 and 53 are opened or closed to form the interlocks. Likewise, the top grate or guard 56, which is hingedly mounted in the upper portion of the conveyor, can also have an interlock switch 57. As seen, the interlock microswitch 57 is mounted on an end wall of the hopper and the pivot pin (hinge) of the upper guard 56 extends thru the wall with an eccentric member to actuate the switch 57. Further, interlocks 57 and 54, respectively, can also be provided which cooperate with the guards 52 and 53 whereby upon opening of any of the guards the depositor 1 is disenabled and will not operate. Such safety features are known in industry. FIG. 5 shows a schematic diagram for the air supply system. As shown, air enters the system via a 3-way valve 62. By switching the valve from the position shown, air can also be exhausted to deactivate or depressurize the system. The valve 62 is connected via conduit means 63 thru a filter 64, pressure regulator 65 and a lubricator 66, to a 4-way, pilot-operated solenoid valve 67. The conduit means 63 then includes two conduits 68 and 69, each having connected therein, respective flow control valves 70 and 71 which are in turn, connected to the cylinder 39. FIG. 6 shows the electrical schematic for the depositor 1. As shown, a source of electricity 75 is electrically connected to solenoids 76 and 77 of the valve 67. As shown, one of the conductors 78 has connected therein a plurality of series connected switches. The first switch 79 is the main on/off switch and is manually operated; then in series are the switch 57 and two switches 54. Theses microswitches are interlocks and prevent the system from being activated in the event one or more of the guards is not in a closed position. As seen, the switches 50 and 51 and their respective solenoids 76 and 77 are connected in parallel to provide for separate operation of the respective solenoids. A depositor as described above was made with the hopper having a length of 48 inches, screen hole diameters of 1/2 inch with dead spaces of approximately two inches at each end of the screen. A lower screw with a two inch pitch and a two inch diameter with a gap A of 3/4 inches and a gap C of 1/4 inch and an upper screw having a diameter of four inches and a gap B of 11/4 inches and a gap D of 1/4 inches and a total included wall angle of 36° was operated. It was observed visually that the operation of this hopper produced an extremely uniform distribution of raisin which required only washing to effect. From the foregoing, it is seen that a depositor is provided which provides both versatility, portability and effective operation for a variety of materials. A particularly described depositor which was built provided exceptionally good depositing results on nutmeats, ground nutmeats, raisins, toasted coconut and the like. It provided operating results better than any known food depositor including vibrator trays, oscillating grates and screw feeders which feed particulates out the end of the screw instead of the side of the screw as is done by the present invention. Depositing with the present invention resulted in the ability to deposit particulates without destroying or damaging their texture, provide a uniform distribution both by weight with time and across the width of the depositor. Further, the present depositor is not only versatile and portable, but is inexpensive to manufacture. It is to be understood that while the present invention has been described in reference to certain types and arrangements of components the present invention is not to be limited thereto except to the extent that such limitations are found in the claims.

A depositor is provided for the feeding or distribution of particulate food pieces, as for example, raisins, nutmeats, etc. The depositor includes a pair of superposed screws positioned in a hopper over an outlet screen member. By oscillating rotational movement of the screws, the particulates are fed from the hopper through the screen onto a dough sheet or the like under the depositor.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. Non-Provisional application Ser. No. 12/546,056 filed on Aug. 24, 2009, which is a continuation of U.S. Non-Provisional application Ser. No. 11/650,323 filed on Jan. 5, 2007, which claims priority from U.S. Provisional Application Ser. No. 60/756,304 filed on Jan. 5, 2006, the disclosures of which are hereby incorporated by reference in their entirety. BACKGROUND There are many lotions and products applied to the human body for cosmetic purposes. These products include moisturizers, sunscreens, anti-aging treatments, UV tanning accelerators, sunless tanning products and much more. There are numerous forms of artificial tanning products currently available, including lotions, creams, gels, oils, and sprays. These products are typically mixtures of a chemically-active skin colorant or a bronzer, in combination with moisturizers, preservatives, anti-microbials, thickeners, solvents, emulsifiers, fragrances, surfactants, stabilizers, sunscreens, pH adjusters, anti-caking agents, and additional ingredients to alter the color reaction. There exist many automated systems for applying artificial tanning products and often include a closed booth provided with a spraying system. The spraying systems typically use high pressure compressed air nozzles, along with a fluid supplied to the nozzle to create an atomized spray directed towards the body. Currently, these booths are mostly closed, are limited to applying only one product per session, and create a foggy closed environment for the user. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings and descriptions that follow, like parts are indicated throughout the drawings and description with the same reference numerals, respectively. One of ordinary skill in the art will appreciate that one element can be designed as multiple elements or that multiple elements can be designed as one element. An element shown as an internal component of another element can be implemented as an external component and vice versa. The figures are not drawn to scale and the proportions of certain parts have been exaggerated for convenience of illustration. FIG. 1 is a front-right perspective view of one embodiment of an automatic body spray system 100 ; FIG. 2 is a front-left perspective view of the automatic body spray system 100 ; FIG. 3 is a perspective view of one embodiment of a spray column 102 showing one embodiment of a slide out drawer 108 holding multiple solution containers 160 a - c; FIG. 4 is a perspective view of one embodiment of a rotating nozzle column 131 ; FIG. 5 is a detailed perspective view of the slide out drawer 108 holding multiple solution containers 160 a,b,c for use in the spray system 100 ; FIG. 6 is a side view of one embodiment of a fluid container 160 ; FIG. 7 is a perspective view of the backside of the slide out drawer 108 holding multiple solution containers 160 a,b,c showing fluid pumps 113 a - c; FIG. 8 is a perspective view of one embodiment of the spray column 102 with the back cover removed to expose the internal components; FIG. 9 is a perspective view of the nozzle arms 128 a,b and fluid solenoid valves 115 a,b,c located in the spray column 102 ; FIG. 10 is a detailed perspective view of one embodiment of an HVLP nozzle assembly 124 ; FIG. 11 is a perspective view of the HVLP turbine 118 , CPU controller 122 , and user interface 117 located in the spray column 102 of the spray system 100 ; FIG. 12 is a perspective view showing the backside of the mist extraction column 103 with the rear cover removed; FIG. 13 is a perspective view showing a mist extraction fan 142 , a mist extraction filter 140 , a filter compartment 141 , a filter wash down nozzle 146 , and an internal column wash down nozzle 147 of the spray system 100 ; FIG. 14 is a perspective view showing the mist extraction filter 140 removed from the mist extraction column 103 and also showing the mist extraction column 103 inlet vents 145 ; FIG. 15 is a perspective view showing one embodiment of a waterfall wash-down hose 149 ; FIG. 16 is a perspective view showing one embodiment of a sump pump 150 waste water removal system and sump pump filter 152 ; FIG. 17 is a side section view showing the sump pump 150 incorporated into a sump pump basin 151 that is integrated into the base 104 with a sump pump filter 152 ; FIG. 18 is a flow chart illustrating one method for operating the automatic body spray system 100 to coat the human body that can be employed by a controller. DETAILED DESCRIPTION FIGS. 1 and 2 illustrate left and right perspective views, respectively, of on embodiment of an automatic body spray system 100 . The system 100 includes a base 104 configured to support a human body 109 . Extending vertically from the perimeter of the base 104 are a spray column 102 , a mist extraction column 103 , and partial side walls 105 a , 105 b , which together defined a spray booth to house the user therein. These partial sidewalls 105 a,b contact the spray column 103 and continue in a curved pattern toward the spray column 102 (see also FIG. 15 ). The partial sidewalls 105 a,b also seat against the base 104 at the bottom of the system 100 . The partial sidewalls 105 a,b stop short of the spray column 103 to allow for user access into the system 100 . The partial sidewalls 105 a,b can be of any shape or size and can be modified to provide the desired amount of mist containment. A partial top 180 can also be provided to keep any excess mist from escaping out the top of the system 100 . In an alternative embodiment, the system 100 can include full-size sidewalls, instead of partial walls. In a preferred embodiment, the system 100 can be employed to apply sunless tanning solutions as well as other solutions onto a human body 109 . Exemplary sunless-tanning solutions include one or more colorants, such as dihydroxyacetone, crotonaldehyde, pyruvaldehyde, glycolaldehyde, glutaraldehyde, otho-phthaldehyde, sorbose, fructose, erythrulose, methylvinylketone, food coloring, or any other available colorant. The sunless tanning solutions can additionally or alternatively include one or more bronzers, such as lawsone, juglone, or any other available bronzer. It will be appreciated that the sunless-tanning solutions can include additional ingredients, such as moisturizers and scents, to make the solution more appealing to a user. While the system 100 can be employed as a sunless tanning spray system, it can also be employed to spray other fluids onto the human body. For example, the system 100 can be configured to spray sunscreens, suntan lotions, moisturizing lotions, sunless tanning pre-spray treatments, tanning accelerators, sunburn treatments, insect repellants, skin toners, skin bleaches, skin lighteners, anti-microbial compositions, exfoliants, nutriments or vitamins, massage aides, muscle relaxants, skin treatment agents, burn treatment agents, decontamination agents, cosmetics, or wrinkle treatments or removers, or any other solution or lotion desired to be applied to the human body. As shown in FIG. 3 , the spray column 102 includes two high volume, low pressure (HVLP) atomization nozzles 106 a,b fluidly connected to an HVLP turbine (not shown) with an air supply hose and also fluidly connected to at least one fluid container 160 . With the assistance of the HVLP turbine, the HVLP nozzles 106 a,b are configured to eject an atomized mist of fluid. In alternative embodiments (not shown), the spray column 102 may include one HVLP nozzle or more than two HVLP nozzles. In another embodiment (not shown), a high pressure fluid pump may be employed, instead of the HVLP turbine. Each HVLP nozzle 106 a,b is coupled to a linear slide (not shown) that is configured to move the HVLP nozzles 106 a,b up and down vertically, thereby adjusting the vertical of the HVLP nozzle 106 a,b . In this configuration, the HVLP nozzles 106 a,b are moveably mounted to the spray column 102 , such that the spray pattern of the HVLP nozzles 106 a,b is sufficient to completely coat the human body 109 with a desired fluid, solution, or lotion. In an alternative embodiment as shown in FIG. 4 , a vertically standing column 131 that rotates back and forth about its vertical axis can be employed. One or more HVLP nozzles 106 can be mounted to the rotating column 131 and be connected to an HVLP turbine with an air supply hose and also fluidly connected to at least one fluid reservoir or container 160 . This column can be automatically rotated back and forth to automatically coat the human body. With reference back to FIG. 3 , the system 100 includes three fluid containers 160 ac contained in the drawer 108 . In alternative embodiments, the system 100 can include two or less containers or more than three containers provided in the drawer 108 . As shown in FIG. 3 , a start button 110 and an LCD user interface panel 107 are also provided. The start button 110 is used to initiate a session. The LCD user interface is used to set up a session and also to perform other functions including, but not limited to, defining the system parameters, turning on a wash down function, turning on a light, and viewing session counts. FIG. 5 illustrates a perspective view of the fluid container drawer 108 with the drawer 108 opened to expose the fluid containers 160 a,b,c . The drawer 108 provides for a simple method of accessing the containers 160 . The drawer 108 includes a pull handle 111 and a key lock 112 for security purposes. In this embodiment, the drawer 108 is attached to the spray column 102 with two slide rails 113 a,b . The drawer 108 can also be attached to the spray column using a rotating mount or any other type of mount. As discussed in more detail above, the fluid containers 160 a - c can hold sunless tanning solutions or other types of fluids. In one embodiment, each fluid container 160 a - c can hold a different sunless-tanning solution. The different solutions can have different chemical compositions which affect the hue of the resulting tan. Alternatively, one fluid container (e.g., the first fluid container 160 a ) can contain water or another dilution agent to dilute a solution contained in the second solution container (e.g., the second fluid container 160 b ). The contents of the different fluid containers can be mixed in various combinations to provide a range of shades, thereby allowing the user to select a preferred tanning shade. Also, the fluid containers can hold other types of solutions to be applied to the human body. One control method for applying the solutions can be to apply a first atomized solution, dry the body with air only coming from the HVLP nozzles, apply a second atomized solution, dry the body with air only coming from the HVLP nozzles, apply a third atomized solution and then dry the body with air only coming from the HVLP nozzles. FIG. 6 illustrates a side view of one embodiment of a fluid container 160 . In this embodiment, the fluid container 160 includes a handle 164 , a male quick disconnect valve 161 at an opening located at one end portion of the fluid container 160 , and a vent 162 provided at the other end portion of the fluid container 160 . The fluid container 160 can also include a check valve 163 to ensure that fluid flows in only one direction such that, when the fluid container 160 is empty, the check valve 163 will prevent any residual solution from leaking out when the fluid container 160 is removed. It will be appreciated that the fluid container 160 can be configured differently in shape and size from the one illustrated in FIG. 6 . Also, it will be appreciated that different fittings such as interchange couplings, poppet couplings, or threaded couplings, can be used to dispense solution from the fluid container 160 . In one embodiment, the fluid containers 160 a - c are removable. Alternatively, the spray column 102 can house fixed fluid containers that can be filled with solution while still in spray column 102 when the solution level falls below a predetermined threshold. As shown in FIG. 4 , each fluid container 160 a - c is inverted such that the male quick disconnect valve 161 mates with a female quick disconnect fitting 165 a - c disposed in the drawer 108 . When a new fluid container 160 is added to the system 100 , the male quick disconnect valve 161 of the fluid container 160 is snapped into the female quick disconnect fitting 165 a - c in the drawer 108 . The vent 162 on the fluid container 160 can then be opened to equalize the air pressure inside the fluid container 160 , allowing fluid to flow freely. FIG. 7 is a perspective view of the inside of the drawer 108 containing three fluid pumps 113 a - c positioned below the female quick disconnect fittings 165 a - c . The first pump 113 a is configured to pump the solution held in the first fluid container 160 a along a fluid flow path F 1 through the hose assembly 116 to the HVLP nozzle assemblies 106 a,b . The second pump 113 b is configured to pump the solution held in the second fluid container 160 b along a fluid flow path F 2 through the hose assembly 116 to the HVLP nozzle assemblies 106 a,b . the third pump 113 c is configured to pump the solution held in the second fluid container 160 c along a fluid flow path F 3 through the hose assembly 116 to the HVLP nozzle assemblies 106 a,b . In one embodiment, the pumps 130 a,b,c are positive displacement pumps. Any other type of fluid pump may suffice. It will be appreciated, however, that one or more of the pumps 113 a,b,c can be positioned anywhere in the drawer 108 . FIG. 8 illustrates a simplified perspective view of the interior of the spray column 102 . FIG. 9 is a close up view of FIG. 8 showing the HVLP nozzle mounting arms 128 a,b in one embodiment of the system 100 . The nozzle mounting arms 128 a,b also hold fluid solenoid valves 115 a - c . These solenoid valves 115 a - c turn on or off the fluid flow through fluid paths F 1 , F 2 , and F 3 between fluid pumps 113 a - c and the HVLP nozzle assemblies 106 a,b . The solenoid valves are controlled by the controller 122 . The valves 115 a - c can also be any type of suitable control valve. The hose assembly 116 holds the fluid paths F 1 , F 2 , and F 3 as well as the air path A 1 . The three fluid paths F 1 , F 2 , F 3 route to each solenoid valves 115 a - c , respectively, and than to each nozzle assembly 106 a,b . The air path A 1 routes to each nozzle assembly 106 a,b from the HVLP turbine 118 and through hose assembly 116 . FIG. 10 shows a detailed perspective view of an HVLP nozzle 106 and mounting arm assembly 124 . The top of nozzle body 126 mounts to the bottom side of the nozzle mounting bracket 129 . The nozzle mounting bracket 129 mounts to the moveable nozzle arm 128 a or 128 b . The HVLP air supply line A 1 enters the nozzle body 126 from the backside and the three fluid lines F 1 , F 2 , F 3 all enter the nozzle body 126 from one of the other sides. The fluid paths for F 1 , F 2 , F 3 all merge toward the center of the nozzle body 126 internally and exit at nozzle tip 127 . The HVLP air supply from the air path A 1 also exits the nozzle body 126 at the nozzle tip 127 . In this embodiment, the HVLP air and the fluid are externally atomized at the nozzle tip 127 . It can be appreciated that any number of fluid paths may enter the nozzle body 126 . Also shown in FIG. 10 are check valves 133 a - c . The nozzle body 126 with multiple inlet ports and the check valves 133 a - c allow multiple solutions to enter the nozzle body 126 and eliminate any cross contamination of different fluids. FIG. 11 is a close up view of FIG. 8 showing the HVLP fan 118 mounted inside the spray column 102 . The hose assembly 116 carries the air path A 1 from the HVLP fan 118 to the nozzle assemblies 106 a,b . The HVLP fan 118 can be controlled on or off by use of a relay or other type of electronic switch. The relay or switch is controlled by the main controller 122 . This HVLP fan 118 acts as the air source to atomize any desired solution or fluid. Another embodiment is to have a heating source that the HVLP air passes through to provide a warmer spray and dry session to the user. This heating source can be controlled by the controller 122 . In the illustrated embodiment, the controller 122 is configured to control the operation of the system 100 . Specifically, the controller 122 is configured to operate the HVLP nozzles, HVLP turbine, pumps, valves, and other electrical or electro-mechanical devices in the system 100 . Suitable controllers can include a processor, a microprocessor, a control circuit, a PLC, or any other appropriate control device. FIG. 11 also shows the controller 122 and the LCD user interface panel 107 . The main controller 122 can be programmed many ways to operate the system 100 for its desired function. For example, in one embodiment, the controller has pre-programmed parameters such as fluid pump values (these control the speed of each fluid pump 113 a - c via pulse width modulation which in turn controls how much fluid is applied over a period of time therefore controlling the intensity level of the fluid being sprayed), linear slide speed (this can control the speed of a linear slide that moves the nozzles 106 a,b vertically up and down; this will also control the amount of solution applied over time and also the length of each application session), number of spray passes (this parameter controls how many times the body is sprayed). Any other variable that controls the operation of the machine can be stored and modified with the LCD interface display 107 and main controller 122 . With continued reference to FIG. 7 , the LCD interface display 107 and main controller 122 can be programmed and configured to perform many unique application sessions. In one embodiment, a linear slide that moves nozzles 106 a,b up and down vertically can be controlled with a motor drive system and any type of position encoding device. The encoding device can be connected to the main controller 122 so that the controller always knows the position of the nozzle arm 128 a,b . This encoding system allows a user to select a partial body spray application. For example, the user can select to spray just their face, input their head height, and the system 100 will spray just their face with the desired solution or combination of solutions at the selected levels. Another example is that the user selects to just spray their legs or their whole body, excluding their legs or face or both. A height monitoring sensor can also be added to the control system so that it automatically adjusts the nozzle 106 a,b positions for each user. This can also be used for full body sprays where the starting height of the nozzles 106 a,b are adjusted to the height of each user, thereby reducing the amount of solution sprayed for bodies shorter than the maximum height of the nozzles 106 a,b. With reference back to FIGS. 1 and 2 , the system 100 also includes a mist extraction column 103 a described above. The mist extraction column 103 can be mounted to the base 104 in a relative position opposite the spray column 102 . The mist extraction column is used to capture any excess mist during spray sessions. FIG. 12 is a perspective view showing the internal components of the mist extraction column 103 . The mist extraction fan 142 will be turned on by the controller 122 during a spray session to draw air flow and excess spray mist through vent openings 145 through a filter assembly 140 that is supported by a filter compartment 141 . The mist is captured in the filter 141 and clean air is passed through the fan 142 and out the back of the mist extraction column 103 . The size and CFM of the mist extraction fan 142 can be adjusted to provide the required amount of air flow to contain the mist generated by the HVLP nozzles 106 a,b. FIG. 13 is a detailed perspective view of the internal components of the mist extraction column 103 . Provided in a position relative to filter 140 is a filter wash down nozzle 146 . The filter 140 in this embodiment is oriented in a horizontal position parallel to the ground plane. The mist extraction column 103 also provides for an internal column wash down nozzle 147 . This column wash down nozzle 147 can be used to clean the inside of the mist extraction column 103 to eliminate the buildup of any spray residue that may occur. This internal column wash down nozzle 147 can have a water supply line connected to it with a solenoid valve (not shown). This solenoid valve can be activated by the controller 122 to provide for a mist extraction column 103 cleansing cycle after each spray session or at desired intervals. In another embodiment, a manual valve could be used to control the water supply to the internal column wash down nozzle 147 . The number of fans, filters, and nozzles or orientation of the fans, filters, and nozzles can be modified as needed. FIG. 14 shows how the filter is inserted and removed from the mist extraction column 103 . The filter 140 slides in a direction perpendicular to the front of the mist extraction column 103 and allows for easy removal. The wash down nozzle 146 can have a water supply line connected to it with a solenoid valve (not shown). This solenoid valve can be activated by the controller 122 to provide for an automatic filter cleansing cycle after each spray session or at desired intervals. The horizontal position of the filter 140 in this embodiment allows for the filter cleansing water to be passed through the filter 140 and emptied at the bottom of the mist extraction column 103 . In another embodiment, a manual valve could be used to control the water supply to the filter wash down nozzle 146 . FIG. 15 shows a perspective view of a wash down system hose 149 used for this open system design. Because the system is open, care has to be taken when providing for an automatic wash down system so that excess wash down water does not leak out of the system. This embodiment shows the wash down hose 149 having holes along its length pointed toward its mounting surface. In this embodiment, the wash down hose 149 mounts along both side walls 105 a,b and the mist extraction column 103 . This configuration allows a waterfall-type wash down where the rinsing water is softly directed in a many small streams toward its relative mounting surface and runs down the surface to be cleaned. This waterfall wash down hose 149 can have a water supply line connected to it with a solenoid valve (not shown). This solenoid valve can be activated by the controller 122 to provide for system 100 cleansing cycle after each spray session or at desired intervals. In another embodiment, a manual valve could be used to control the water supply to the water fall wash down hose 149 . FIG. 16 shows a simplified perspective view of a waste water sump pump 150 mounted in base 104 . FIG. 17 shows a side section view of a waste water sump pump 150 mounted in base 104 . The base 104 has an integral drain basin 151 to catch waste water from the various wash down systems described above, including the filter wash down waste water, the internal column wash down waste water, and the system wash down waste water. The waste water from the above mentioned wash down systems flow down from their respective components to be cleaned over the top surface of the base 104 and towards the sump pump basin 151 . The waste water also passes through a filter screen 152 to keep debris from entering the sump pump 150 . The sump pump 150 will then pump out the waste water when its float switch activates the pump. The fluid spraying system 100 can include additional components without departing from the scope of the present application. For example, the system 100 can include fluid detection sensors (not shown) disposed near the bottom of each fluid container 160 a,b,c . The fluid detection sensors can be configured to sense the solution level in each fluid container 160 a,b,c . When the solution level falls below a predetermined threshold, the fluid detection sensors can be configured to transmit a signal to the controller 122 . Upon receipt of the signal, the controller 122 can deactivate the fluid spraying system 100 to prevent air from being pulled into one or all of the fluid flow paths F 1 , F 2 , and F 3 . Exemplary fluid detection sensors that can be employed include capacitive solution detection switches, optical sensors, or piezoelectric sensors. Also, the fluid spraying system 100 can include a heating element (not shown), such as a heating coil or other heating device, that can be placed around or adjacent to the first and/or second and/or third fluid flow paths F 1 , F 2 , F 3 thereby creating a warm, atomized mist of fluid that can be ejected from the nozzles 106 a,b . Additionally, a heating element can be placed around or inside the air flow path A 1 . Alternatively, heating elements can be placed around or adjacent to one or all of the fluid containers 160 a,b,c. FIG. 18 is a flow chart showing one example of a control process. This process shown is for a full body session and a choice between a single solution spray or a multiple solution spray. The multiple solution spray shown in this example is for a two solution multispray but can be configured for any number of multi-session sprays. This flow chart can also apply for face only sprays, leg only sprays, or any other height adjustable spray session. In one specific method to coat the human body, the method can include spraying can the atomized mixture of HVLP air and fluid onto the body and then turning off the fluid supply and moving the nozzles up and down with the HVLP air still on to dry the body. The speed, volume, and temperature natural to the HVLP air source is ideal for drying the body. Hence, the same nozzles that apply the atomized solution can also be used as a drying source when the solution is turned off and the air is turned on. The system 100 described above and illustrated in the figures provides one or more of the following benefits: (1) the system does not require a large external air compressor for air delivery method, (2) the atomized spray using an HVLP air supply does not produce a lingering fog of mist and over spray, because of the lack of fog and over spray, (3) the system does not need to be completely enclosed to capture excess mist and keep it from escaping into the surrounding environment, (4) the user is not subjected to breath or be surrounded by excess fog or mist, and the transfer efficiency of the atomized fluid onto the human body is much higher than with compressed air systems, (5) the system allows many different types of products to be applied to the human body in one application session, (6) the system employs the use of a convenient slide out drawer to access the solution containers for multiple products to be applied, and (7) the system can be programmed to apply a fluid to only user specified areas of the body. While the present application has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the application, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures can be made from such details without departing from the spirit or scope of the applicant's general inventive concept. The system is not designed solely for sunless tanning products or for the purpose for spraying a human body. It can accommodate almost any type of product being sprayed.

An embodiment of an apparatus for extracting excess liquid in a human body spray system includes a spray booth defining a booth volume. The spray booth includes a base configured to support the human body and a column having walls extending vertically from the base and at least one vent opening disposed on a bottom half portion of the column on at least one of the walls. The walls form a hollow interior of the column. The apparatus for extracting excess liquid in a human body spray system further includes an extraction fan disposed within the hollow interior adjacent to a top half portion of the column and configured to create a low pressure volume within the hollow interior and draw air flow and at least some of the excess mist from the booth volume through the at least one vent opening.

TECHNICAL FIELD This invention relates generally to gas lasers and more particularly to matching and drive systems for transversely excited gas lasers. BACKGROUND OF THE INVENTION Interconnection and matching of an RF excited gas laser to an RF generator is typically accomplished by the use of a 50 ohm coaxial transmission line with separate matching networks at both ends. The matching network at the laser end usually steps up the line impedance to a range between several hundred and several thousand ohms, while the matching network at the RF generator end steps the line impedance down to the low values required for the generator's transistor output stage. Other functions of the matching networks are to account for the two different impedance values of the plasma tube, before and after breakdown. Yet another function of the matching network is to cancel reactive components at source and load. U.S. Pat. No. 4,455,658 by Sutter, U.S. Pat. No. 4,169,251 by Laakmann and U.S. Pat. No. 4,363,126 by Chenausky et al. are typical examples of such interconnect systems. An exception to these standard techniques is taught by Laakmann in U.S. Pat. No. 4,837,772. In this disclosure a lumped constant matching system is used directly between the RF generator's output stage transistors and the laser. No interconnect cables are used, for reasons disclosed there. However, the main feature of that disclosure is the "self-oscillating technique" that eliminated much of the complexity of matching drive frequency and laser as well as accounting for the two different impedance states of the plasma contained within the laser's plasma tube. In U.S. Pat. No. 4,373,202 by Laakmann, et al., the technique is disclosed of using a 75 ohm quarter wave transmission line within a 50 ohm system to automatically adjust power in order to decrease "hot spots" within the plasma tube and provide a more stable discharge. However, both laser and power source are still matched to 50 ohm impedances and produce sinusoidal waveforms. SUMMARY OF THE INVENTION The present invention provides a matching system between a source of RF energy and a laser tube which is simple in design while also providing a very good match. In general, the invention is an RF excited gas laser system. The laser system comprises a plasma tube, a voltage source of RF energy, and a transmission line. The plasma tube has an electrical input port, a discharge section and means for outcoupling laser energy. The plasma tube produces laser energy upon ignition of a gas contained within the plasma tube. The input terminal has a real impedance at a predetermined operating frequency. The voltage source of RF energy has a source impedance much lower than the plasma tube impedance at the operating frequency. The transmission line is connected at an input end to the voltage source and at an output end to the plasma tube. It has an electrical length substantially equal to an odd number of quarter wavelengths at the operating frequency and has a characteristic impedance (with the plasma ignited) intermediate the impedance of the voltage source and the impedance of the plasma tube. In one embodiment, the drive source of the laser system is balanced and the load due to the laser system is unbalanced. In this case, the transmission line is coaxial and is used to convert from the balanced source to the unbalanced load. In another embodiment, the drive source, transmission line and laser system load are all balanced. In either embodiment the drive source may be a square wave. In a further embodiment, the balanced transmission line comprises two coaxial cables having substantially equal lengths. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a conventional matching network known in the prior art, connected between a gas laser and an RF generator. FIG. 2 is a schematic diagram of the final stage of a conventional RF generator known in the prior art. FIG. 3 is a schematic diagram of a lumped constant matching network known in the prior art. FIG. 4 is a schematic diagram of a first embodiment of the invention, including a quarter wave transmission line connected between a balanced pair of output transistors and an unbalanced laser load. FIG. 5 is a schematic diagram of a third embodiment of the invention, including two quarter wave transmission lines of FIG. 4 and further including a 1:1 isolation transformer. FIG. 6 is a schematic diagram of a second embodiment of the invention, including the quarter wave transmission line of FIG. 4 and further including a 1:1 isolation transformer. DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a schematic diagram of a conventional matching network 10 known in the prior art, connected between a gas laser and an RF (radio frequency) generator. The matching network 10, which can be grounded to electrical ground 12, has an input 14 and an output 16. The input 14 is connected to an output end of an inner conductor 20 of a transmission line 18. An outer shield 22 of the transmission line 18 is electrically grounded at the transmission line's output end. An input end of the transmission line 18 is connected to an RF source 24. One side of the RF source 24 is connected to the center conductor 20 of the transmission line 18 and the other side of the RF source 24 is connected to the outer shield 22 of the transmission line 18. The output 16 of the matching network 10 is connected to a laser tube 26 of a gas laser. The laser tube 26 includes at least two electrodes 28a and 28b which transversely excite a lasing gas mixture contained within the laser tube 26 through the application of an RF voltage across the electrodes 28a and 28b. FIG. 2 is a schematic diagram including a final stage 30 of a broadband RF source 24 known in the prior art. The final stage 30 operates at 28 volts DC and uses two transistors 32a and 32b operating in a push-pull configuration. The voltage drops due to the transistors 32a and 32b are usually negligible. As is well known in the art, a transformer 34 is used to match the impedance of the final stage 30 to an input 36. The final stage 30 is connected to a matching network 38 within the RF source 24 to match the impedance of the final stage 30 to the desired impedance at the output 40. A 50 ohm output is conventional for an RF generator. FIG. 3 is a schematic diagram of a lumped constant matching network 50 known in the prior art. It represents one way of matching the impedance of a drive transistor 51 to the impedance of the electrode 28a of the laser tube 26. In this laser configuration, the electrode 28b is electrically grounded. The matching network 50 includes inductors 52 and 54 and adjustable capacitors 56, 58 and 60 to perform the desired impedance-matching operation. FIG. 4 is a schematic diagram of a first embodiment of the invention, which provides for simpler impedance matching between a source 24' and a laser or plasma tube 26'. The laser tube 26' differs from the laser tube 26 in that it includes two pairs of electrodes, pairs 70a-70b and 72a-72b. The electrodes are arranged in a square configuration with the electrodes of each pair of electrodes positioned diametrically opposite each other within the laser tube 26'. Electrode 70a is connected to the output of the RF source 24 through the impedance-matching circuit to be described subsequently, and electrode 70b is connected to electrode 70a through an inductance coil 74. Both of electrodes 72a and 72b are electrically grounded. A transmission line 80 is directly connected between the collectors of the transistors 32a and 32b and electrode 70a of laser tube 26'. An outer shield 80a of the transmission line 80 is connected to the collector of transistor 32b and to ground through a blocking capacitor 82 at the laser tube end of the transmission line since it carries DC voltage, as inner conductor 80b of the transmission line 80 is connected to the collector of transistor 32a. The coil 74 shown is disclosed in U.S. Pat. No. 4,837,772. The coil 74 serves the purpose of neutralizing capacitive reactance and generating bi-phase excitation, as explained in said U.S. patent. The transmission line 80 typically has a 50 ohm nominal impedance and has an electrical length of a quarter wave. Accordingly, at the typical excitation frequency of 45 MHz it has a physical length of about 130 centimeters due to the velocity factor of the transmission line's dielectric. The impedance (R) of the electrodes 70a of the laser tube 26' averages about 200 ohms when the laser tube 26' is lit, as disclosed by U.S. Pat. No. 4,805,182. This assumes that the laser tube 26' has a square bore of 4.8 millimeters, contains a laser gas at a pressure of 60 torr and has discharge electrodes that are 37 centimeters long. These laser tube parameters are appropriate for a gas laser operating at resonance with an input power of about 110 W. In a CO 2 laser this corresponds to a continuous wave (CW) laser output power of about 15 W. This value of the impedance R corresponds to an electrode-to-electrode impedance of 800 ohms. The impedance of the discharge section of the laser tube 26' is several thousand ohms in the non-ignited state. (These impedances are measured unsymmetrically.) However, the impedance R depends on power delivered. It is lower with higher input power. The input power of 110 W corresponds to the maximum laser output power. In a second aspect of the invention, the signal driving the pair of transistors 32a and 32b is derived from a crystal controlled or variable frequency generator through a transformer 84, as shown in the schematic diagram of FIG. 6. It may also be derived by connecting a feedback path between laser tube 26' and an input 86 as taught by U.S. Pat. No. 4,837,772. The transistors 32a and 32b can be operated in class B or AB to produce near sinusoidal voltage outputs with negligible saturation drops as is well known in RF amplifier design. The collector-to-collector RMS voltage between the transistors 32a and 32b is therefore essentially two times the supply voltage and the required load resistance to deliver a power P is R=V 2 /P. For the indicated parameters this load resistance is 14.3 ohms. As is well known in the art, a quarter wave transformer to match the two impedances must have characteristic impedance (Z) equal to the geometric mean of Z/r=R/Z. According to the theoretical load relationship given above, to deliver 110 W, the push-pull stage has peak-to-peak output voltage of 56 V or 39.5 V RMS. The corresponding load impedance is 14.3 ohms. Thus, the impedance Z of a quarter wave line to match the two impedances has to satisfy the expression: Z/14.3=200/Z. An impedance Z of approximately 53 ohms satisfies this. This is close enough to standard values of transmission lines (approximately 50 ohms) to make this invention realizable. For the indicated parameters, this value of impedance Z calculates to 53 ohms. This is a very fortunate circumstance as this value is close enough to the value of commercial cables which range between 50 and 53 ohms for most popular sizes. This matching technique then provides further simplification of the already low production cost of the "all-metal" laser technology disclosed in U.S. Pat. No. 4,805,182 and the simple "self oscillating" excitation technology disclosed in U.S. Pat. No. 4,837,772. Contrary to prior art disclosed in U.S. Pat. No. 4,373,202 by Laakmann, the quarter wave transmission line 50 is used between the RF source 24 and the laser tube 26'. The RF source 24 is represented by the alternately saturated transistors 32a and 32b. Indeed the drive does not have to be a sine wave. The transistors 32a and 32b can be operated in a square wave fashion. Referring to Table 1, no power is delivered to the laser tube 26' or to the transmission line 50 at any odd harmonic. This is so because the laser drive impedance is zero at all frequencies except at the fundamental. The interconnect transmission line 50, however, represents a odd multiple of a quarter wave lengths for all harmonics. Such lines have the same property as a quarter wave transmission line. When terminated with a short, their input impedance is infinite. Therefore no current is delivered to the input of the transmission line 50 (as seen by the transistors 32a and 32b) at any of the harmonics. This represents an ideal load for the transistors 32a and 32b and accounts for the observed high efficiency of this invention. Collector efficiency is a theoretical 100 percent compared to a theoretical 78 percent for class B linear amplifiers. Observed efficiencies are about 75 percent versus 50 percent in the class B amplifiers of the prior art. TABLE 1______________________________________Square Wave Drive Amplitude TransmissionHarmonic x Line Length Laser Transistor(n) 2 VCC λ Impedance Load______________________________________1 4/π 1/4 200 ohms 14.3 ohms3 4/3π 3/4 very low very high5 4/5π 5/4 very low very high______________________________________ The Fourier expansion of a square wave shows terms of 4/nπ where n is the harmonic number. If the drive system is used in a near square wave mode, the fundamental RMS voltage for perfect transistors 32a and 32b and the RF source 24 is 56/√(2)×4/π=50.4 V. Again solving for the load resistance to deliver 110 W results in r=V 2 /P=23 ohms. Accordingly, a matching quarter wave transmission line has an impedance of 67.8 ohms. This is close to the impedance of a standard 75 ohm transmission line. Alternately, if a 75 ohm transmission line is used between the 200 ohm load and the switching supply, a power of 90.7 W would be delivered to the laser tube. For a 50 ohm transmission line the power delivered is 203 W. As pointed out earlier, the impedance of the laser tube 26' decreases with increased power. The actual power delivered to a laser tube 26' would be below the actual power that is delivered to a resistive load. Thus, there are enough variables between choices of transmission line 80, waveshape, supply voltage and laser operating conditions to build practical systems over a wide operating range. The system diagrammed schematically in FIG. 4 uses the transmission line 80 to go between a balanced system (the push-pull transistor pair 32a and 32b) and a ground reference load represented by the laser tube 26'. This is possible since the common mode impedance of a quarter wave transmission line is several hundred ohms at the operating frequency, particularly when coiled up to fit within the laser enclosure. It was not necessary to wind the transmission line 80 around magnetic materials as is done for broadband transmission line transformers well known in the art. Such a transmission line represents a source of radiation that can result in interference to other instruments or communications systems. The transmission line 80 should therefore only be used within a shielded enclosure. FIG. 5 is a schematic diagram of a third embodiment of the invention, including two quarter wave transmission lines of FIG. 4 and further including a 1:1 isolation transformer. The circuitry shown schematically in FIG. 5 is identical to that shown in FIG. 4 except that the inner conductors of the conventional separate quarter-wave transmission lines 81a and 81b are connected to transistors 32a and 32b, respectively. The outer conductors of the transmission lines 81a and 81b are grounded. The outputs of the quarter-wave transmission lines 81a and 81b are respectively connected to the electrodes 70a and 70b in the laser tube 26'. The electrodes 70a and 70b are connected together via coil 74. The two transmission lines 81a and 81b have substantially equal lengths. If desired, the transmission lines 81a and 81b can be packaged together in a single cable. FIG. 6 shows a method of overcoming the radiation problem of the embodiment of FIG. 4 by using a balanced to unbalanced (balun) type transformer 85. As is well-known in the art, such transformers can be built very effectively for unity transformation. Such is not the case for step-up or step-down transformers. A typical implementation uses twisted wire wound around a high permeability ferrite core, which is usually toroidal. The close physical proximity and core permeability assure a nearly perfect transformer, particularly for this uncritical narrow band application. The transmission line 80 in this case can be used as an interconnect between shielded enclosures without causing much radiation. All of the advantages and considerations discussed above apply. A distinct advantage of the disclosed laser system is the ease of laser tube breakdown. The laser tube 26' initially has a high impedance. The drive frequency injected into the input 86 has a frequency close to resonance of the laser tube 26'. The high laser tube impedance is reflected to a very low impedance, typically a few ohms by the inverse transformation property of the quarter wave transmission line 80. The RF source 24 is a voltage source that will cause very high current to flow until breakdown is achieved in the laser tube 26', particularly when operated in square wave fashion. In this context, the definition of a voltage source is one of very low source impedance, when compared to the applied load. The instantaneous peak currents for a few microseconds are far above CW conditions. The amount of power delivered is likewise high. Breakdown is achieved within a few microseconds. After breakdown has occurred, power will self-regulate as taught in U.S. Pat. No. 4,373,202. The high peak currents seen by the transistors 32a and 32b are combined with correspondingly low collector voltages. This is relatively safer than the situation in the prior art when the power delivered during firing is usually less due to mismatch, with high peak voltages on the transistors. The matching system of this invention has also significantly reduced the incidence of the yet unsolved "dark" effect, where a laser may take several seconds to fire initially after prolonged shut down. This extremely simple technique has accomplished the following: (1) Very few parts are necessary in comparison to the existing state-of-the-art designs. Additionally there are no matching adjustments. (2) The quarter wave transmission line 80 is driven by a voltage source, as represented by the two alternately saturated output transistors 32a and 32b. Extremely high voltages are delivered to the discharge section of the laser tube 26' to accomplish fast breakdown of the laser gas. This helps to produce high speed pulsing as well as to overcome starting difficulties after prolonged shutdown. RF power delivered is highest just prior to breakdown of the gas. In the prior art the RF power delivered is usually less during the ignition phase due to mismatch of the 50 ohm system used. (3) Automatic power compensation improves discharge stability, as disclosed by U.S. Pat. No. 4,373,202. (4) Electrical losses are minimal due to the absence of conventional matching networks. Electrical efficiency is about 15 percent better than prior art as described in U.S. Pat. No. 4,837,722. Additional gains in efficiency are the result of using the transistors 32a and 32b as switches, as will be explained in (6) below. (5) The system 10 can be used with conventional fixed frequency excitation, as well as in a "self-oscillating" scheme as described in U.S. Pat. No. 4,837,772. (6) The transistors 32a and 32b can be operated in a switching or deep saturation mode with very high efficiency of conversion to sine wave power at the laser tube 26'. This is due to the unique combination of elements when used with the harmonics of a square wave driving voltage. Therefore, no power is delivered by the transistors 32a and 32b except at the fundamental frequency. Those who are skilled in the art may perceive certain modifications such as changes of active devices, transformer, construction of transmission lines, or other circuit elements, including analogy between series and parallel resonance as taught by U.S. Pat. No. 4,837,772. All such modifications are deemed to be within the scope of the invention which is only to be limited by the following claims:

A system for improved drive and matching between an RF power source and a plasma tube in a laser system. The system uses standard 50 or 75 ohm quarter wave transmission lines as the sole interconnect and matching elements between discharge electrodes and drive transistors. The drive transistos may be operated in deep saturation or as switches providing near square wave output to approach the 100 percent theoretical electrical efficiency of switching power supplies. The system features better initial breakdown, bettwer discharge uniformity and power stability under narrow drive pulse conditions, lower matching electrical losses, and extreme simplicity and low cost.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to two provisional patent Applications Nos. 61/661,619 and 61/661,622 filed on Jun. 19, 2012. The disclosure of the prior applications are incorporated herein by reference. TECHNICAL FIELD The invention generally relates to high volume low speed (HVLS) fans, and more specifically HVLS fans utilizing short take off and landing (STOL) technology. BACKGROUND OF THE INVENTION Interior climate control and air circulation is difficult in certain applications, particularly including large open structural areas such as found in a factory or warehouse setting. This difficulty is encountered in both hot and cold seasonal conditions, where heat during cold weather heating migrates towards the ceiling of a building and humidity tends to migrate down during hot and humid weather conditions. Therefore, there is an interest in forcing air from the ceiling, down, towards an occupied main floor during cooler weather, thus saving costs for heating, and circulating air more generally in warmer weather conditions resulting in a perceived cooler environment due to evaporation. Solutions to these conditions include forced ventilation through ceiling-based plenums in HVAC applications. Another solution is the use of ceiling fans to circulate the ambient air. However, both of these solutions are inadequate for circulating large volumes of air in large open areas such as is common in a factory or warehouse setting. HVLS fans provide improvement over HVAC systems and/or traditional ceiling fans by moving larger volumes of air. These systems have their own limitations including relatively low efficiency in both the amount of energy used and amount of circulated air per unit of energy use. STOL technology is a known solution for allowing aircraft to take off and land within constrained short distances. STOL technology has been adapted to aircraft airfoil profiles for providing improved lift and efficient movement of air under slower take off or landing speeds. Known aircraft wing profiles utilizing STOL design technology include EPPLER-420 and FX63-137 profiles. But, these airfoil profiles utilizing STOL design technology have not been adapted for use in HVLS fan systems. In addition, due to their size and weight resulting from fans reaching diameters from 12 feet to 20 feet, or more, there is risk to persons and equipment below the fan in the event of a failure causing a portion, or all, of the fan to fall. Therefore, there is opportunity and need for improving air circulation systems in large open areas. Further, there is need for improving HVLS fan systems to provide higher efficiencies and maximize airflow in large open spaces such as warehouses, manufacturing facilities, places of worship, gymnasiums/health clubs, auto dealerships and more. There is also a need for providing safety measures in the implementation of HVLS fan systems. SUMMARY OF THE INVENTION AND ADVANTAGES The present disclosure addresses these needs and issues by providing an HVLS fan system incorporating STOL technology in a system that increases air volume and circulation while also increasing efficiencies and which does not add significant costs, weight, or manufacturing complexity to this system. It is therefore an object of the disclosure to take advantage of STOL technology and thus increase efficiency of an HVLS fan system. It is a further object of the disclosure to provide greater efficiency in the movement of air in the HVLS system. It is an additional object of the disclosure to provide an economical and lightweight solution to better circulate air in large areas. Another object of the disclosure is to provide a safety mechanism for preventing injury or damage in the event of a failure in the HVLS fan. The present disclosure provides an HVLS fan system utilizing STOL technology and having better efficiency, including an airfoil form adapted to provide higher airflow at lower circulation rates while decreasing drag on the airfoils and increasing efficiencies. The system also includes an airfoil profile consistent with STOL technology. More particularly, an airfoil utilizing an EPPLER 420 or substantially similar airfoil design. In addition, the system includes a wing tip advantageously formed to reduce drag of the airfoil. Further, the system employs a hub displacing the airfoil at an angle most suitable for maximizing the benefits of the STOL technology. More particularly, this includes a hub providing an attachment angle of between seven and ten degrees to the airfoil, and even more particularly eight degrees to the airfoil. Together, the disclosure provides an HVLS fan system offering improved efficiency, reduced drag, and increased air flow for the benefit of better circulating air in a large open area. In addition, the system includes a safety system including attachment of a retaining member, one for each airfoil, on the hub that passes through a retaining bracket in a manner that in the event of the airfoil becoming dislodged from the hub or the hub itself becoming disconnected from the drive system prevents the hub and/or the airfoils from falling. The retaining brackets do not touch or otherwise notably increase air resistance in the system but provide for an important safety measure where failure can cause catastrophic consequences. Another safety aspect is a series of overlapping brackets which mount on the top of the airfoils which interlock each of the airfoils to the one next to it. This will prevent an airfoil from becoming dislodged from the system in the case of failure. In addition, guy wires connect the frame of the HVLS fan system to a support member such as a ceiling support beam. Other objects and features of the present invention will become apparent when viewed in the light of the detailed description of the preferred embodiments when taken in conjunction with the attached drawings and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: FIG. 1 is a perspective view of the HVLS fan system of the invention; FIG. 2 is a side sectional view in spaced apart form showing the HVLS fan system of FIG. 1 ; FIG. 3 is a side cross sectional view of an airfoil of the HVLS fan system; FIG. 4 is a top view of an airfoil of the HVLS fan system; FIG. 5 is a side view of a wingtip fence of the HVLS fan system; FIG. 6 is a top view of the wingtip fence of FIG. 5 ; FIG. 7 is a back view of the wingtip fence of FIG. 5 ; FIG. 8 is a top view of a central hub of the HVLS fan system; FIG. 9 is a side view of the central hub of FIG. 8 ; FIG. 10 is a perspective view of a cylinder of the HVLS fan system; FIG. 11 is a cross-sectional view of the cylinder of FIG. 11 ; FIG. 12 is a top view of a securing plate of the HVLS fan system; FIG. 13 is a perspective view a of portion of the HVLS fan system in spaced apart form emphasizing the locations of safety brackets; and FIG. 14 is a table containing X-Y data coordinates for the airfoil profile of the HVLS fan system. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following figures, like reference numerals are used to identify identical components in the various views and embodiments. The following example is meant to be illustrative of preferred embodiments for the invention. However, those skilled in the art will recognize various additional alternative embodiments. Referring to FIGS. 1-13 , an HVLS fan system 10 of the disclosure includes airfoils 12 coupled at one end to a central hub 14 and extending in the other direction to a distal end having a wingtip fence 16 . The central hub 14 is coupled to a motor 18 for rotating the airfoils 12 . The motor 18 is connected to a frame 20 which is coupled to a lower yoke 22 and an extension bar 24 which in turn is coupled to an upper yoke 26 . The upper yoke 26 is illustrated as connected to a building member 28 such as a girder or other similar structures suitable for bearing the weight of the HVLS fan system. The extension bar 24 as a backup secures the HVLS fan system to the building member 28 with a safety cable 30 . Guy wires (not shown) are also used to secure the frame to weight bearing locations on either the builder member 28 or other support structure in the ceiling of the building. Typically, four guy wires are used and attached at somewhat equally spaced locations around the HVLS fan system. As illustrated, the HVLS fan system has six airfoils 12 equally spaced around the central hub 14 . The HVLS fan system airfoils 12 are generally positioned between ten feet and fifty feet above the floor with optimum height generally between twenty feet and thirty feet. The motor 18 is a standard approximately one horsepower electric motor known to those skilled in the art. To accomplish the objective of HVLS, the airfoils 12 are each between five and twelve feet in length and more preferably between six and ten feet in length. Looking up at an installed HVLS fan system 10 it will rotate in a counterclockwise direction 32 . The airfoils 12 are formed out of a lightweight material such as aluminum or a composite metal that can be formed into an airplane wing type shape with a hollow core. However, it should be appreciated that the airfoils can be formed of a variety of different materials, including plastics, polyurethanes, and other suitably rigid materials adequate to form an airfoil, or even combinations of such materials known to those skilled in the art. It should also be appreciated that the length of the airfoils 12 can be increased or decreased to suit a certain application. In addition, it should be appreciated that the HVLS fan system 10 can include airfoils 12 without inclusion of wingtips fences 16 . Further, motor 18 may be any manner of other suitable motor including suitable horse power or amperage rating know to those skilled in the art. The airfoils 12 are fan blades comprised of a generally elliptical top surface 34 and a generally elliptical bottom surface 36 . The airfoils 12 are configured to mount to the central hub 14 through the use of an H-shaped connector member 37 , connected on one end to the central hub 14 and on the other end to a receptors 39 interior to the airfoil 12 . The airfoil further includes a leading edge 38 and a trailing edge 40 . The trailing edge 40 maintains a radius of approximately 0.043 inches. The airfoil may be a substantially hollow extruded aluminum section of approximately 0.1 inches in thickness when mounted to the central hub 14 including STOL-type airfoils. The wingtip fence 16 has a substantially vertical member 42 with a connecting perimeter 44 defined by the profile of the airfoil 12 , to which it is attached. The wingtip 16 consisting of a lower concave edge 46 , an upper convex edge 48 , a leading 50 and trailing edge 52 which sits flush with the airfoil 12 end edge. The vertical member 42 protrudes rearward relative to the leading edge 50 of the airfoil 12 . The vertical member 42 consists of two planes. The lower plane is parallel to the connection plane of the airfoil and wingtip fence, while the upper plane is angled outward relative to the innermost end of the airfoil. Adding the wingtip fence 16 to the airfoils 12 improves the aerodynamic properties of the airfoils, by reducing drag and therefore increasing the fan's overall efficiency. The wingtip fence 16 includes a mounting member 54 which connects to an inner portion of the receptors 39 of the airfoil 12 . The wingtip 16 is configured to secure the connection to the airfoil 12 through protruding guide points 56 that couple to an inner perimeter of the airfoil 12 thus mounting the wingtip fence 16 to the airfoil 12 . The central hub 14 provides a securing system for the fan assembly, where a bottom frame member 58 is connected to a securing plate 60 by fasteners 62 . The central hub 14 assembly includes a cylinder 64 coupled to the central hub 14 and retaining members 68 , one for each of the airfoils 12 that when connected to the central hub 14 extend through an opening in the securing plate 60 thus providing a safety stop against a failure involving a break in the motor 18 or its coupling to the cylinder 64 or a drive shaft 70 . The cylinder 64 has an opening 72 for receiving the drive shaft 70 . The drive shaft 70 does not connect directly to the cylinder 64 , but instead couples to a bushing (not shown) which couples the drive shaft 70 to the cylinder 64 through simultaneous expansion and contraction, as is known to those skilled in the art. The central hub 14 includes flanges 74 which are displaced from a plane defining the central hub at an angle predetermined for the airfoils 12 . The angle of the flanges 74 positions the airfoils 12 at an angle most suitable for maximizing the benefits of the STOL technology. More particularly, this includes an attachment angle of between seven and ten degrees to the airfoil, and even more particularly eight degrees to the airfoil. Another safety aspect is a series of overlapping brackets including a first bracket 76 and second bracket 78 which mount on the top of the airfoils and interlock each of the airfoils 12 to the one next to it. The first bracket 76 and second bracket 78 are held in place with fasteners 80 . This prevents the airfoil 12 from becoming dislodged from the system in the event of failure. In addition, guy wires (not shown) connect the frame of the HVLS fan system to a support member such as a ceiling support beam. After applicants first conceived that STOL technology would benefit efficiencies and overall performance of an HVLS fan, experimentation was undertaken under preset parameters and requirements to optimize a STOL airfoil profile. This experimentation, undertaken at the request and direction of the applicants by Haiyer Lou, Ph.D, M. Eng at TurboMoni, confirmed that of two airfoil profiles adapting STOL technology an airfoil following EPPLER-420 parameters was more efficient when angled at approximately 8 degrees from horizontal. Thus, referring to FIG. 14 , the airfoils 12 are predetermined to comply with STOL technology and provide high efficiency operation including higher lift and lower drag for the application of an HVLS fan. The EPPLER-420 profile disclosed in FIG. 14 provides dimensionless cord lengths that provide for defining X-Y coordinates by multiplying with the real cord (the distance from leading edge point to the trailing edge point). Thus, an HVLS fan system of the invention, including its various embodiments, provides a high efficiency cost effective, secure means of addressing and providing air movement in large open areas. While particular embodiments of the invention have been shown and described, numerous variations and alternative embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.

An HVLS fan system uses STOL technology for airfoils and angle of attack thus optimizing air movement efficiency and reducing drag. The HVLS fan system includes wingtip fence end caps to the airfoils for improving efficiency by reducing drag. The HVLS fan system also includes an interconnection of the airfoils to a securing plate thus providing a failsafe and reduced potential for damage or injury resulting from failure of the connection between the airfoil array and a drive unit such as an electric motor and associated gearing.

[0001] The present invention relates to a composition, which contains several kinds of components beneficial to human eye health, and provides supplements for indispensable materials such as lutein, zeaxanthin, zinc, and selenium necessary for human eyes. BACKGROUND [0002] Eye health is a permanent and important topic. The focus on eye health has never stopped. Currently, various eye protection products are present on the market. People have been trying to prevent or treat all kinds of eye discomfort or ophthalmic disease, such as asthenopia, amblyopia, myopia, cataract, age-related macular degeneration (ARMD) and the like, and keep eyes healthy by absorbing or using some natural or synthetic substances or some trace elements. Although the effects of using these products are different, people have not stopped to seek for the optimal medical compositions to achieve the best effect on eye protection. [0003] Among all of eye protection components, lutein and zeaxanthin are two very important substances. Lutein and zeaxanthin are natural carotenoids which widely exist in vegetables, flowers, fruits and some algae living creatures. They are widely used in many fields such as food, health products, cosmetic products, medicine, tobacco, feed for animals and poultries. Recently researches have found that lutein and zeaxanthin not only have a close relationship with a disease of age-related macular degeneration (ARMD), but also can effectively prevent from visual failure. Lutein and zeaxanthin are two only carotenoids existing in the human retina, which are selectively deposited in the macular region and the whole retina, generally there is the highest density around the macular fovea and a gradually decreased density around the retina. These macular pigments are able to effectively prevent from occurrence of the oxidation reaction in the retina. It can be assumed that an effective method of treating and preventing the macular degeneration or injury is to supplement lutein and zeaxanthin. Furthermore, lutein and zeaxanthin can be used to improve the visual efficacy in the absence of ARMD, for example, there are some good healthcare functions for the juvenile myopia, senile blindness caused by muscle degradation, and the eye damage caused by the ultraviolet radiation from sunlight and computer. A lot of clinical testing results show that the amount of recommended ingestion of lutein and zeaxanthin for human body is 6 mg per day. It is generally thought that the acceptable daily intake (ADI) of lutein crystal is 25 mg/person/day, which can not result in the carotenoid yellow dermatosis. [0004] More and more people are interested in the special physiological functions of lutein and zeaxanthin. Currently, a large amount of health food and fortified food containing the above-mentioned two natural pigments have present abroad. The FDA of USA approved the use of lutein and zeaxanthin as food supplement agents in foods in 1995 to improve nutritive values, for example, the use in beverage to be beneficial for eyesight and in infant food. At the end of 2006, the use of lutein as coloring agent in beverage, baked food, frozen food, and food such as fruit jelly and fruit jam with the addition amount of 50˜150 mg/kg, has been also approved in China. In the meanwhile, the use of lutein as nutrition enhancement agent has been approved as well. The impetus of new market makes the market value of lutein reach 139 million dollars in 2004, but only 64 million in 1999. The tendency of this strong increasing is still continued, and BBC thinks that the increasing rate will reach 6.1% every year by 2009. [0005] In addition to lutein and zeaxanthin, other substances such as zinc and selenium are beneficial to eye health. Studies show that zinc can increase sensitivities of optic nerves, and is the main component of the retinal reductase in the retinal cells. The enhancement of zinc can directly affect synthesis and metabolism of xanthopsin from vitamin A, which may be helpful for the effect of retinal, thereby to increase human adaptability to weak light. The lack of zinc may also affect the ability of retinal cell to distinguish from colors. Selenium is an important trace element to maintain eyesight, and is the main component of glutathione peroxidase. The lack of selenium may lead to amblyopia. Accordingly, the carophylls such as lutein, zeaxanthin and zinc, selenium are good partners. The combination of the four components has the effects on promotion enhancement, and has effects on protection of eyes, prevention of juvenile myopia, sthenopia among workers and senile visual failure. [0006] In view of further attention to eye health and the aforementioned identification for eye protection function, foods including lutein or selenium or zinc or three of them, such as beverage, milk, yoghurt, and the like, have also present in the market, but the function or addition of zeaxanthin have been generally ignored in these products. Actually, in some sense, zeaxanthin has the same, or even better, eye protection effects as lutein. For example, at the macular of the human retinal central, the content of zeaxanthin is generally about two times of that of lutein. The nearer the edge of the retinal is, the higher the content of lutein is, and the relatively lower the content of zeaxanthin is. At the most edge of the retinal, the content of lutein is about three times of that of zeaxanthin, in the human plasma, the content of lutein is also about three times of that of zeaxanthin, it shows that there is a transfer mechanism from lutein to zeaxanthin in human body. Meanwhile, other studies also found that some of lutein ingested in by human body will change into zeaxanthin. Accordingly, zeaxanthin plays non-negligible roles in eye health of human. The results of our preliminary test in human body also proved that visual performances of human eyes, especially visuognosis persistence and eye consciousness symptoms may be well improved, when being supplemented with the mixture of lutein and zeaxanthin added with selenium and zinc. [0007] As described above, there are various eye protection products in the market, however, most of them are compositions containing one, or two, or three components of the four. For example, CN1625395A relates to the composition of lutein and zeaxanthin used for glare protection; CN1253091 relates to a dairy product or beverage to be beneficial for eyesight containing lutein, zinc and selenium; US2005/0147648 keeps eyes healthy by supplementing a combination of zeaxanthin, polyunsaturated fatty acids, plant extracts and the like; U.S. Pat. No. 7,267,830 relates to the objective of improving eye health level by supplementing carotenoids and vitamin A, C, DHA and some trace elements, wherein in the disclosed formulation, the proportion of lutein and zeaxanthin is kept at the level of 3:1, and the function of zeaxanthin is not specially mentioned; U.S. Pat. No. 7,282,225 supplements vitamin A, C, E, carotenoids (beta-carotenoid, lutein, zeaxanthin), trace elements by dietary to improve visual performance and acuity, but the unique effect of zeaxanthin on improving visuognosis persistence is not highlighted in this formulation. [0008] The present invention provides a composition containing the aforementioned four components in a certain proportion. Such composition provides trace elements for human eye health, such as lutein, zeaxanthin, zinc, and selenium, and is conducive to human eye health, and is especially beneficial for the improvement of visuognosis persistence of human eyes, for the asthenopia remission, and improvement of eye consciousness symptoms. SUMMARY [0009] Lutein and zeaxanthin are the only two kinds of carotenoids existing in the human retina, which are closely related to the macular degeneration. Zinc and selenium can increase adaptabilities to weak light and color distinguishing ability of human eyes. The compositions containing the aforementioned four substances in a certain proportion are beneficial for human eye health when being used in formula food. The objective of the present invention is to describe the formula food including the composition described above. [0010] As used herein, the term “visual performance” is referred to as visual function such as acuity, contrast sensitivity, glare recovery, dark adaptation, visuognosis persistence, light stress recovery and color vision and the like, wherein special attention is the increase of visuognosis persistence, such as asthenopia remission and improvement of eye consciousness symptoms. [0011] As used herein, the term “visuognosis persistence” is an index for evaluating asthenopia. When the cortical excitability in the human brain reduces, the visual analysis function decreases, in the process of eyes fixating at object, invisible duration will increase and visuognosis duration will decrease. The percentage of visuognosis duration to fixation duration is referred to as visuognosis persistence, which is an index to comprehensively reflect the visual performance and psychological function. The visuognosis persistence (%)=visuognosis duration/total fixation duration* 100. [0012] As defined herein, “formula food” is referred to as various foods for enhancing certain nutritional function, such as formula milk powder, including infant formula milk powder or senile formula milk powder and the like; various functional beverages such as beverages containing milk, orange juice beverages, coke, carbonated beverages, suspended beverages, and so on; baked food such as cakes, biscuits and so on, and, etc. including various dietary supplement tablet, capsule for nutrition supplements. [0013] The present invention provides a formula food beneficial for eye health, comprising lutien, zeaxanthin, zinc, and selenium. [0014] As defined herein, “eye health” is referred to as good effect of increasing of visuognosis persistence and asthenopia remission and improvement of eye consciousness symptoms as well as preventing from or treating Age-related Macular Degeneration (ARMD). [0015] Wherein, the zinc is inorganic zinc salt or organic zinc salt. The inorganic zinc salt is zinc sulfate or zinc sulfite; the organic zinc salt is zinc orotate or zinc ascorbate. [0016] The selenium is inorganic selenium salt or organic selenium salt. The inorganic selenium salt is selenophosphate, or selenite. The organic selenium salt is selenoamino acid or selenium yeast or selenium-enriched yeast. Wherein, the selenophosphate is sodium selenophosphate; the selenite is sodium selenite or sodium selenate; the selenoamino acid is L-selenomethionine; the selenium yeast or selenium-enriched yeast is Brewer's yeast or Barker's yeast. [0017] Wherein the amount of the lutein added in the formula food is 0.3˜250 mg/kg. The amount of the zeaxanthin added in the formula food is 0.3˜250 mg/kg. Preferably, the amount of the lutein added is 2.0˜80 mg/kg in the formula food; the amount of the zeaxanthin added is 2.0˜80 mg/kg in the formula food. The proportion of mass of lutein and zeaxanthin is in the range of 0.05:10.0˜10.0:0.05. Preferably, the proportion of mass of lutein and zeaxanthin is in the range of 0.1:2.0˜2.0:0.1. More preferably, the proportion of mass of lutein and zeaxanthin is in the range of 0.1:2.0˜1.0:1.0. In particular, the lutein and zeaxanthin of the present invention may be obtained by mixing in a certain proportion, that is, they have been mixed in a certain proportion before the dosage available in preparation to add into the formula food is obtained. One of the mixing proportions of lutein and zeaxanthin is in the range of 0.05:1.0˜1.0:0.05. [0018] Wherein the amount of zinc added in the formula food is 4˜80 mg/kg which is based on the weight of pure zinc when the added zinc is organic or inorganic zinc. The amount of selenium added in the formula food is 30˜350 μg/kg which is based on the weight of pure selenium when the added selenium is organic or inorganic selenium. [0019] Wherein the lutein exists in the form of crystalloid or aliphatic ester is extracted from natural sources. The dosage form of the lutein added is microencapsulated powder, or homogeneously dispersed in edible vegetable oils, or aqueous dispersible emulsion Wherein the mass percent of the lutein in the corresponding dosage form is 1˜25 wt %. [0020] Wherein the zeaxanthin exists in the form of crystalloid or aliphatic ester is extracted from natural sources or obtained by chemical synthesis. The dosage form of the zeaxanthin added is microencapsulated powder, or homogeneously dispersed in edible vegetable oils, or water dispersible emulsion. Wherein the mass percent of the zeaxanthin in the corresponding dosage form is 1˜25 wt %. [0021] Wherein the formula food further contains at least one antioxidant, including synthetic tocopherol (vitamin E), natural tocopherol (natural vitamin E), sodium D-ascorbate (sodium iso-VC), ascorbic acid (vitamin C), ascorbyl palmitate, phosphatidylcholine. [0022] Wherein the formula food is applied in various formula milk powder, various functional beverages, various baked food, various dietary supplement tablet and capsule. In particular, the formula food can be used in various food for the purpose of enhancing certain nutritional function, such as formula milk powder, including infant formula milk powder or senile formula milk powder and the like; various functional beverages like beverages containing milk, orange juice beverage, coke, carbonated beverage, suspended beverage, and so on; baked food like cakes, biscuits and so on, and various dietary supplement tablets, capsules and so on for the purpose of nutrition supplement are included as well. [0023] In the present invention, the suitable dosage form of the lutein, zeaxanthin, zinc and selenium to be added should be dissolved in water or oil in advance, and then added during the suitable step of formula food processing. [0024] The addition of the components as described above will not affect the initial taste in the scope of the present invention. [0025] Within the scope of the present invention, the composition of the four substances mixed in a certain proportion can be made into soft capsules or hard capsules or tablets for oral administration thereby achieving the objective of diet supplementing. [0026] In addition, a certain amount of antioxidant such as synthetic tocopherol, natural tocopherol, ascorbyl palmitate, phosphatidylcholine and so on may be added into the composition, or into the single component dosage of lutein, zeaxanthin, zinc, selenium. [0027] The beneficial effect of the present invention is supplementing the mixture of lutein, zeaxanthin, zinc, selenium, and properly increasing the amount of zeaxanthin relative to lutein to improve the effect of the composition on asthenopia remission and improvement of eye consciousness symptoms. The formula food of the present invention is beneficial for human eye health, in particular, for the increase of visuognosis persistence and asthenopia remission and improvement of eye consciousness symptoms. BRIEF DESCRIPTION OF THE DRAWINGS [0028] FIG. 1 shows the changing rate of visuognosis persistence after feeding trails for the subjects from different test groups; and, [0029] FIG. 2 shows the percentage of the subjects whose visual fatigue is ameliorated in respective test group. DETAILED DESCRIPTION [0030] The features of the present invention will be more clearly understood by reference to the following embodiments, which are not to be construed as limiting the present invention. EXAMPLE 1 Asthenopia Remission Test of Lutein, Zeaxanthin, Zinc, Selenium [0031] 278 subjects, ranging in age between 17-23 years old, who use video display terminals (VDT) for long time and tend to have asthenopia, were selected for this test according to the voluntary principle, with the exception the following subjects: those who have certain ophthalmic disease that may affect the testing results; those who have administered the relevant drugs, health products or applied the other treatments for long or short time that may affect the determination for the results; those who do not confirm to the inclusion criteria, and do not feed the tested drug according to regulations, or have incomplete information and the like that may affect performance or safe-determination. [0032] Control group and test group were established in the test, wherein 48 subjects were randomly selected to administer placebo in control group. The test group was further divided into five groups (I, II, III, IV, V), 46 subjects for each group. The subjects in each test group were successively treated with drug compositions in the form of tablets for 35 days, once per day, two tablets once. The test is adopted for the comparison before and after treatment as well as the comparison among groups. [0000] TABLE 1 Groups Of Human Test And Compositions Of Feeding Tablets Groups Compositions of feeding tablets Control group Placebo Test group I 12 mg lutein Test group II 9 mg lutein and 3 mg zeaxanthin Test group III 4 mg lutein and 8 mg zeaxanthin Test group IV 9 mg lutein, 3 mg zeaxanthin, 27 mg zinc and 120 μg selenium Test group V 4 mg lutein, 8 mg zeaxanthin, 27 mg zinc and 120 μg selenium [0033] 1. Except the active ingredients shown in the formulation, in which the lutein was CarolGold™ 10% TAB; zeaxanthin was CarolZea™ 10% TAB; zinc was zinc ascorbate; selenium was selenoamino acid like L-selenomethionine; the others were necessary for tablets, such as hydroxymethylcellulose, modified starch, and the like. The total weight of the tablet was 450 mg. [0034] 2. The appearance, color and weight of placebo tablet were the same as those of feeding tablet. [0035] Each index, including physiological index and functional index, was tested once at the beginning and end of the feeding test. Physiological index includes general physical examination, blood, urine, stool routine examination, blood biochemical criterion examination, type-B ultrasound, chest X-ray, and other corresponding examinations like electrocardiographic examination. Functional index includes ocular symptom examination: Inquiring the case history, and observing the subjective symptom of eyes, for example, eye swelling, ophthalmalgia, photophobia, visual blurring, eye dryness and the like. Aggregate the score before and after feeding according to symptoms degree (3 points as severe symptom, 2 points as moderate symptom, 1 points as mild symptom), and calculate the symptom improvement rate according to the improvement of the main symptom (1 point as effective improvement for each symptom, 2 points as obvious improvement). Detection of visuognosis persistence: the percentage of visuognosis duration to fixation duration is referred as visuognosis persistence. The detection duration is 3 min, and the average value of two detections was taken. [0036] Data processing: data were analyzed by using the statistical software STATE6.0. Paired t test was used for self-control data, and group t test was used for comparison between the mean values of two groups. The later one needs homogeneity test for variance to do suitable variable transformation for the data with non-normal distribution or variance non-homogeneity until the normal variance homogeneity is met, and then the transformed data is used for t test; if the transformed data could not meet the normal variance homogeneity, t test or rank-sum test is used; but for the data whose coefficient of variation is too large, for example, CV>50%, the rank sum test should be used. X 2 test was used for performance indexes. [0037] The change of visuognosis persistence for control and test groups after feeding is shown in FIG. 1 . The visuognosis persistence for subjects in test group was remarkably improved after feeding compared with that before feeding (P<0.05), wherein, it increased 10.27±8.56% for those supplemented with lutein only; the improving extent varied depending on the proportion of lutein to zeaxanthin when the mixture of lutein and zeaxanthin was supplemented, for example, under the condition that the total amount is constant, the visuognosis persistence increased 14.56±10.21% for those supplemented with lutein and zeaxanthin in the proportion of 3:1 and 18.23±7.25% for those supplemented with lutein and zeaxanthin in the proportion of 1:2. There is remarkably difference between the two (P<0.05). When supplemented with a certain amount of trace elements zinc, selenium, the visuognosis persistence of subjects is further promoted, and even the improving extent are more obvious when the proportion of lutein and zeaxanthin was lower(P<0.01). [0038] It can be seen the visual improvement effect from the index of subjective symptom of eyes (clinical symptom score, refer to FIG. 2 ). That is, the results before and after feeding have statistical significance (P<0.001). Furthermore, when supplemented with the mixture of lutein, zeaxanthin, zinc, selenium, in which the content of zeaxanthin was higher than that of lutein, the highest total efficiency was up to 59.45%, which was remarkably different (P<0.05) from that when the content of lutein was higher (total efficiency was 47.27%). [0039] The results of general physical examination, blood biochemical criterion examination, urine routine examination for control group and test group were within the normal range before and after feeding. The results of chest fluoroscopy, electrocardiographic, abdominal examination by type-B ultrasound, chest x-ray for control group and test group were within the normal range before and after feeding. [0040] The test proves the advantages of the present invention, that is, supplementing the mixture of lutein, zeaxanthin, zinc, selenium, and properly increasing the amount of zeaxanthin relative to lutein can improve the effect of the composition for asthenopia remission and improvement of eye consciousness symptoms. EXAMPLE 2 The Eye Health Beverage Containing Lutein, Zeaxanthin, Zinc, Selenium [0041] The beverage contained sugar, citric acid, sodium citrate, vitamin B, lutein, zeaxanthin, zinc, selenium, plant extracts, and the like. Based on the total amount of 1000 g, 60 mg lutein, 0.3 mg zeaxanthin, 40 mg zinc, 30 μg selenium are contained thereinto, other components and water are also included. Certain amount of synthetic tocopherol was used as antioxidant. The used lutein was in the form of 5% CWS-B beadlet, and zeaxanthin was in the form of 5% CWS dry powder. The zinc was zinc orotate and selenium was L-selenomethionine. [0042] The beverage was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 2. [0000] TABLE 2 The Comparison Of Change Of Visuognosis Persistence In Two Groups After Feeding With Eye Health Beverage (X ± S, %) Groups Before feeding After feeding Promoted percentage Test 53.26 ± 7.87 68.48 ± 6.98 15.26 ± 9.54*** ### group (n = 54) Control 52.35 ± 8.01 53.47 ± 4.98 1.12 ± 4.55*     group (n = 54) [0043] Self-comparison before and after feeding, ** P<0.05, *** P<0.001, Comparison between test group and control group after feeding, ### P<0.001 EXAMPLE 3 The Infant Formula Milk Powder Containing Lutein, Zeaxanthin, Zinc, Selenium [0044] Besides conventional carbohydrate, fat, protein, vitamins A, D, E, K, B, trace elements, oligosaccharide, the infant formula milk powder further contained components beneficial for eye health like lutein, zeaxanthin, zinc, selenium. Based on the total amount of 1000 g, 0.3 mg lutein, 60 mg zeaxanthin, 4 mg zinc, 150□μg selenium are contained thereinto. The used lutein was in the form of 1% CWS dry powder, and zeaxanthin was in the form of 5% CWS dry powder. The zinc was zinc sulfate; selenium was Baker's yeast rich in selenium; and natural tocopherol was antioxidant. [0045] The formula milk powder was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 3. EXAMPLE 4 The Milk-Containing Beverage Containing Lutein, Zeaxanthin, Zinc, Selenium [0046] The beverage contained sugar, whole milk powder, sodium citrate, vitamin B, stabilizer, lutein, zeaxanthin, zinc, selenium, and the like. Based on the total amount of 1000 g, 250 mg lutein, 12.5 mg zeaxanthin, 80 mg zinc, 180 μg selenium, certain amount of ascorbyl palmitate are contained thereinto, other components and water are also be included. The used lutein was in the form of 10% CWS-B beadlet, and zeaxanthin was in the form of 1% CWS dry powder. The zinc was zinc orotate and selenium was sodium selenophosphate. [0047] The beverage was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 3. EXAMPLE 5 The Formula Milk Powder for Middle-Aged Persons and Old People Containing Lutein, Zeaxanthin, Zinc, Selenium [0048] Besides conventional carbohydrate, fat, protein, vitamins A, D, E, K, B, trace elements, oligosaccharide, the formula milk powder contained components beneficial for eye health like lutein, zeaxanthin, zinc, selenium. Based on the total amount of 1000 g, 12.5 mg lutein, 250 mg zeaxanthin,40 mg zinc, 350 μg selenium and a suitable amount of phosphatidylcholine are contained thereinto. The used lutein was in the form of 1% CWS dry powder, and zeaxanthin was in the form of 5% CWS dry powder. The zinc was zinc sulfate; selenium was sodium selenate. [0049] The formula milk powder was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 3. EXAMPLE 6 The Bread Containing Lutein, Zeaxanthin, Zinc, Selenium [0050] Besides conventional plain and strong flour, sugar, butter for stirring, yeast, certain amount of bread improver, the formula bread contained components beneficial for eye health like lutein, zeaxanthin, zinc, selenium. Based on the total amount of 1000 g, 54.7 mg lutein, 19.4 mg zeaxanthin, 60 mg zinc, 150 μg selenium and a proper amount of sodium D-ascorbate are contained thereinto. The used lutein was in the form of 10% CWS dry powder, and zeaxanthin was in the form of 12% CWS dry powder. The zinc was zinc sulfite; selenium was selenium-enriched Brewer's yeast. The obtained breads have uniform fabric, golden yellow color and flavor taste. [0051] The formula milk powder was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 3. EXAMPLE 7 The Fruit Jelly Containing Lutein, Zeaxanthin, Zinc, Selenium [0052] Besides conventional fruit jelly gel, sugar, calcium lactate, citric acid, the formula fruit jelly contained components beneficial for eye health like lutein, zeaxanthin, zinc, selenium, and was also added with certain amount of mixed tocopherol, sodium iso-VC. Based on the total amount of 10000 g, 15.0 mg lutein, 1.4 mg zeaxanthin, 40 mg zinc, 250 μg selenium are contained thereinto and ascorbic acid was used as antioxidant. The used lutein was in the form of 25% dry powder, and zeaxanthin was in the form of 5% CWS dry powder. The zinc was zinc orotate; selenium was sodium selenite. The obtained fruit jellies had attracting, lucid, and transparent color. [0053] The formula milk powder was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 3. EXAMPLE 8 The Soft Gelatin Capsule Rich in Lutein, Zeaxanthin, Zinc, Selenium [0054] Based on the weight of 200 mg per soft capsule, the following components are included: 12 mg aliphatic ester of lutein, 2 mg zeaxanthin, 10 mg vitamin E, 15 mg vitamin C, 3.6 mg zinc orotate, 24 μg sodium selenite, 18 mg phosphatidylcholine, 30 mg soybean oil, wherein the used aliphatic ester of lutein has the concentrate 20.0% OS and the zeaxanthin was in the form of 25% OS. [0055] The soft gelatin capsule was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 3. EXAMPLE 9 The Soft Gelatin Capsule Rich in Lutein, Zeaxanthin, Zinc, Selenium [0056] Based on the weight of 200 mg per soft capsule, the following components are included: 3.6 mg lutein (80 mg/kg), 12 mg zeaxanthin, 8 mg vitamin E, 10 mg vitamin C, 1.8 mg zinc orotate, 32 μg sodium selenite, 24 mg phosphatidylcholine, 21 mg soybean oil, wherein the used aliphatic ester of lutein has the concentrate 25% OS and the zeaxanthin was in the form of 20% OS. [0057] The soft gelatin capsule was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 3. [0000] TABLE 3 The Changing Rate Of Visuognosis Persistence After Feeding Among Different Groups Test groups Control groups No. of Average changing No. of Average changing Examples subjects rate (%) subjects rate (%) Example 3 21 25.98 ± 8.79* 19 5.87 ± 2.40 Example 4 22  8.98 ± 1.56** 23 −1.51 ± 0.46   Example 5 24  14.06 ± 2.85** 21 3.78 ± 1.58 Example 6 19 12.23 ± 3.65* 19 3.62 ± 1.76 Example 7 23 15.85 ± 8.54* 24 0.84 ± 1.12 Example 8 21  13.57 ± 1.69** 21 0.17 ± 2.03 Example 9 27  16.45 ± 5.23** 22 −1.45 ± 0.74   Comparison with control groups, *P < 0.05, **P < 0.01. EXAMPLE 10 The Bread Containing Lutein, Zeaxanthin, Zinc, Selenium [0058] Besides conventional plain and strong flour, sugar, butter for stirring, yeast, certain amount of bread improver, the formula bread contained components beneficial for eye health like lutein, zeaxanthin, zinc, selenium. Based on the total amount of 1000 g, 80.0 mg lutein, 19.4 mg zeaxanthin, 60 mg zinc, 150□μg selenium and a proper amount of sodium D-ascorbate are contained thereinto. The used lutein was in the form of 10% CWS dry powder, and zeaxanthin was in the form of 12% CWS dry powder. The zinc was zinc sulfite; selenium was selenium-enriched Brewer's yeast. The obtained breads have uniform fabric, golden yellow color and flavor taste. [0059] The formula milk powder was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 4. EXAMPLE 11 The Soft Gelatin Capsule Rich in Lutein, Zeaxanthin, Zinc, Selenium [0060] Based on the weight of 250 mg per soft capsule, the following components are included: 40 mg aliphatic ester of lutein, 5 mg zeaxanthin (20 mg/kg), 10 mg vitamin E, 15 mg vitamin C, 3.6 mg zinc orotate, 24 μg sodium selenite, 18 mg phosphatidylcholine, 20 mg soybean oil, wherein the used aliphatic ester of lutein has the concentrate 75% OS and the zeaxanthin was in the form of 20% OS. [0061] The soft gelatin capsule was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 4. EXAMPLE 12 The Soft Gelatin Capsule Rich in Lutein, Zeaxanthin, Zinc, Selenium [0062] Based on the weight of 250 mg per soft capsule, the following components are included: 20 mg lutein (80 mg/kg), 20 mg zeaxanthin (80 mg/kg), 8 mg vitamin E, 10 mg vitamin C, 1.8 mg zinc orotate, 32 μg sodium selenite, 14 mg phosphatidylcholine, 26 mg soybean oil, wherein the used zeaxanthin was in the form of 25% OS. [0063] The soft gelatin capsule was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 4. EXAMPLE 13 Tablet Rich in Lutein, Zeaxanthin, Zinc, Selenium [0064] Based on the weight of 250 mg per Tablet, the following components are included: 40 mg aliphatic ester of lutein, 5 mg zeaxanthin (20 mg/kg), 10 mg vitamin E, 15 mg vitamin C, 3.6 mg zinc orotate, 24 μg sodium selenite, 18 mg phosphatidylcholine, 20 mg soybean oil, wherein the used aliphatic ester of lutein has the concentrate 75% OS and the zeaxanthin was in the form of 20% OS. [0065] The soft gelatin capsule was tested through human test according to the test design similar to that of Example 1, and the results are shown in Table 4. [0000] TABLE 4 The Changing Rate Of Visuognosis Persistence After Feeding Among Different Groups Test groups Control groups No. of Average changing No. of Average changing Examples subjects rate (%) subjects rate (%) Example 10 19 12.53 ± 3.55*  19 3.52 ± 1.76 Example 11 21 13.87 ± 1.59** 21 0.27 ± 2.03 Example 12 27 16.85 ± 5.33** 22 −1.55 ± 0.64   Example 13 21 13.77 ± 1.69** 21 0.27 ± 2.03 Comparison with control groups, *P < 0.05, **P < 0.01. [0066] Although the present invention has been described in connection with the above embodiments, it should be understood that the present invention is not limited to such embodiments and procedures set forth above. The embodiments and procedures were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention. It will be apparent to those skilled in the art that various substitution, modifications and changes may be thereto without departing from the scope and spirit of the invention. Therefore, the intention is intended to cover all alternative constructions and equivalents falling within the spirit and scope of the invention as defined only by the appended claims and equivalents thereto. [0067] The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modification will become obvious to those skilled in the art upon reading this disclosure and may be made upon departing from the spirit of the invention and scope of the appended claims. Accordingly, this invention is not intended to be limited by the specific exemplifications presented hereinabove. Rather, what is intended to be covered is within the spirit and scope of the appended claims. [0068] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements. [0069] Having thus described the invention, it is now claimed:

The present invention provides a formula food comprising lutien, zeaxanthin, zinc, and selenium beneficial for eye health and its application. The formula food is not only applied for dietary supplement tablets and capsules, but also applied for various formula milk powders, various functional beverages, various baked food. The formula food is conducive to the human eye health, especially beneficial for the improvement of visuognosis persistence of human eyes, helpful for asthenopia remission and the improvement of eye consciousness symptoms.

BACKGROUND OF THE INVENTION The invention relates to a method for implementing switching in the time domain, and to a method for implementing switching in the space domain, for signals of several different levels of hierarchy, the signals having a common frame structure. An example of such a frame structure is the frame structure of an STM-1 signal used in the SDH system; this frame structure will be illustrated in greater detail below. The method of the invention can thus be used in both time and space switches. In this connection, the term time switch refers to a device capable of switching the contents of any time slot in the frame structure of an incoming signal to any time slot in an outgoing frame structure (switching in time). In addition to a time switch, this device can also be called a time slot interchanger. The term space switch, in turn, refers to a switch capable of connecting any incoming line to any outgoing line (switching in space). In known switching methods, the switching of e.g. the tributary unit groups (TU-12, TU-2, TU-3) of an STM-1 frame is implemented by giving switching instructions separately to 3, 21 or 63 columns by starting the switching from column 13 on TU-3 level and from column 19 on TU-2 and TU-12 levels. It has thus been possible to effect the switching on one level at a time. Another way has been to switch columns 19 to 270 in blocks of 63 columns, and to give switching instructions separately to columns 13 to 18 on the TU-3 level. In this way it has been possible to effect cross-connection on all three of the levels at the same time. The drawback of the known switching methods is, however, that, in practice they entail fairly complicated equipment. SUMMARY OF THE INVENTION The object of the present invention is to remedy the drawback described above. The idea of the invention is to utilize the frame structure of an incoming signal by defining a basic switching block, which recurs in the frame structure in the same form from the point of view of switching, and to effect the switching of all time slots merely on the basis of an address control memory intended for the switching of the basic switching block by reading the said memory cyclically, and by skipping the switching instructions at the time slots which are not cross-connected. Owing to the solution of the invention, it is not necessary to inform the actual switch about the level of the signals to be cross-connected. The solution thus allows the practical equipment to be implemented in a more simplified manner than before. BRIEF DESCRIPTION OF THE DRAWINGS In the following, the invention will be described in more detail with reference to the examples which are based on an STM-1 signal and illustrated in the attached drawings, in which FIG. 1 shows the basic structure of a single STM-N frame, FIG. 2 shows the structure of a single STM-1 frame, FIG. 3 shows the assembly of the STM-N frame from existing PCM systems, FIG. 4 shows an STM-1 frame and blocks of different sizes contained in it, FIG. 5 shows a time switch and implementation of time switching according to the invention, FIG. 6 is a more detailed view of the read unit of the time switch shown in FIG. 5, FIG. 7A and 7B show how the switching instructions of the address control memory in the time switch of the invention are distributed to the different channels in three separate cases, FIG. 8 shows how the switching instructions of the address control memory in the time switch of the invention are distributed to the channels of different levels of hierarchy in a case where signals of three different levels of hierarchy are switched simultaneously, and FIG. 9 shows a solution of the invention as applied to a space switch. DETAILED DESCRIPTION FIG. 1 illustrates the structure of an STM-N frame used in the SDH network, and FIG. 2 illustrates a single STM-1 frame. The STM-N frame comprises a matrix with 9 rows and N×270 columns so that there is one byte at the junction point between each row and the column. Rows 1-3 and rows 5-9 of the N×9 first columns comprise a section overhead SOH, and row 4 comprises an AU pointer. The rest of the frame structure is formed of a section having the length of N×261 columns and containing the payload section of the STM-N frame. FIG. 2 illustrates a single STM-1 frame which is 270 bytes in length, as described above. The payload section comprises one or more administration units AU. In the example shown in the figure, the payload section consists of the administration unit AU-4, into which a highest-level virtual container VC-4 is inserted. (Alternatively, the STM-1 transfer frame may contain three AU-3 units, each containing a corresponding lower-level virtual container VC-3). The VC-4 in turn consists of a path overhead POH located at the beginning of each row and having the length of one byte (9 bytes altogether), fixed stuff FS located at the following two columns, TU-3 pointers or a null pointer indicator NPI located at the following three columns, fixed stuff or VC-3 path overheads (VC-3 POH) located at the following three columns, and the actual payload section PL. The null pointer indicator NPI is used to separate the tributary unit groups TUG-3 comprising TU-3 units from the tributary unit groups TUG-3 comprising TU-2 units. FIG. 3 shows how the STM-N frame can be formed of existing bit streams. These bit streams (1.5, 2, 6, 8, 34, 45 or 140 Mbit/s, shown on the right in the figure) are packed at the first stage into containers C specified by CCITT. At the second stage, overhead bytes containing control data are inserted into the containers, thus obtaining the above-described virtual container VC-11, VC-12, VC-2, VC-3 or VC-4 (the first suffix in the abbreviations represents the level of hierarchy and the second suffix represents the bit rate). This virtual container remains intact while it passes through the synchronous network up to its point of delivery. Depending on the level of hierarchy, the virtual containers are further formed either into so-called tributary units TU or into AU units (AU-3 and AU-4) already mentioned above by providing them with pointers. The AU unit can be mapped directly into the STM-1 frame, whereas the TU units have to be assembled through tributary unit groups TUG and VC-3 and VC-4 units to form AU units which then can be mapped into the STM-1 frame. In FIG. 3, the mapping is indicated by a continuous thin line, the aligning with a broken line, and the multiplexing with a continuous thicker line. As is to be seen from FIG. 3, the STM-1 frame may be assembled in a number of alternative ways, and the contents of the highest-level virtual container VC-4, for instance, may vary, depending on the level from which the assembly has been started and in which way the assembly has been performed. The STM-1 signal may thus contain, e.g., 3 TU-3 units or 21 TU-2 units or 63 TU-12 units (or an arbitrary combination of some of the above-mentioned units). As the higher-level unit contains several lower-level units, e.g. the VC-4 unit contains TU-12 units (there are 63 such units in a single VC-4 unit, cf. FIG. 3), the lower-level units are mapped into the higher-level frame by interleaving so that the first bytes are first taken consecutively from each one of the lower-level units, then the second bytes, etc. Accordingly, when the VC-4 signal contains, e.g., the above-mentioned 63 TU-12 signals, these signals are located in the VC-4 frame as shown in FIG. 2, i.e. the first byte of the first TU-12 signal is located first, then the first byte of the second TU-12 signal, etc. After the first byte of the last signal, i.e. the 63rd TU-12 signal, the second byte of the first TU-12 signal follows, etc. The following table shows the contents of the columns of the STM-1 frame as a summary, depending on whether the frame contains TU-12, TU-2 or TU-3 units. ______________________________________Col-umnNum-ber TU-12 TU-2 TU-3______________________________________1-9 SOH SOH SOH10 VC-4 POH VC-4 POH VC-4 POH11-12 fixed stuff fixed stuff fixed stuff13-15 NPI NPI TU-3 pointers16-18 fixed stuff fixed stuff VC-3 POH19-81 1 × 63 × TU-12 3 × 21 × TU-2 21 × 3 × TU-382- 1 × 63 × TU-12 3 × 21 × TU-2 21 × 3 × TU-3144145- 1 × 63 × TU-12 3 × 21 × TU-2 21 × 3 × TU-3207208- 1 × 63 × TU-12 3 × 21 × TU-2 21 × 3 × TU-3270______________________________________ The SDH system is described more closely, e.g., in References [1] to [3] (these references being listed at the end of the specification). On the basis of the above, the frame of the STM-1 signal can be illustrated with respect to the switching as shown in FIG. 4. It consists of blocks of two types: e.g. the first 18 bytes, consisting of section and path overheads, on each row form the first block 41, and the following 63 bytes on each row form the second block 42, of which there are four successive ones in a single STM-1 frame 4. The data contained in the first block are not cross-connected (except for columns 13 to 18 in the case of TU-3 signals), but it continues in the same time slots even in the outgoing frame. FIGS. 5 and 6 show the solution of the invention in connection with time switching. FIG. 5 is a block diagram illustrating the structure of the time switch, and FIG. 6 is a more detailed view of the read unit 63 shown in FIG. 5. The time switch shown in this example is the object of copending Finnish Patent Applications No. 923295 and 923296, filed Jul. 17, 1992. However, the method of the invention can also be used in conventional time switches. The time switch (FIG. 5) comprises only one memory block 61, which is twice as large as the largest frame block. In this case the size of the memory block 61 is thus 126 bytes. Writing into the memory is controlled by a simple counter 62, which is not in synchronization with the incoming signal frame (but is in synchronization with the clock signal), and which counts continuously from 1 to 126. The bytes of an incoming signal containing frame blocks of different sizes are written continuously into the memory at the address WA given by the counter, this address being incremented by one for each byte. The writing is effected without synchronization with the incoming signal frame, i.e. starting from an arbitrary location in the frame. The write address WA given by the counter 62 is also supplied to a read unit 63, more specifically to a subtractor circuit 64 therein (FIG. 6), which generates the delay by subtracting the value 63 from the write address (in this case the cross-connection delay has the length of 63 bytes, and in general, it is as long as the duration of the largest frame block in bytes). The read address thus obtained is supplied to an adder circuit 65, which adds the read address to the switching data obtained from the address control memory 66. The above-described basic structure of the STM-1. frame allows TU-2/3 signals to be switched as if they were made of TU-12 signals. This can be done by defining 63 consecutive bytes of the STM-1 frame as a basic switching block. Since all of these blocks (columns 19-81, 82-144, 145-207 and 208-270 in the STM-1 frame) are switched in the same manner, it is not necessary to define more than one switching matrix for them. The address control memory thus has the length of 63 memory locations, it is read cyclically in the manner described above, and it gives cross-connection data to each time slot of said blocks so that each TU-12 channel has its own switching instruction, or each TU-2 channel has three similar switching instructions, or each TU-3 channel has 21 similar switching instructions. In this example, a relative read address is used as the switching data in the address control memory. This means that the switching data at each memory location in the address control memory indicates the relative transition of the data contained in the time slot within the frame structure. The relative address is positive if the signal leaves the time switch in a relatively earlier time slot than it came in, and negative in the opposite case. A relative address can have (integer) values between -62 and +62, but not, however, in every time slot; each time slot has its own acceptable range within which the relative read address can be. The first time slot of each row of each frame block 42 can thus have only positive address values (from 0 to +62), the second time slot can have address values from -1 to +61, etc., and the last time slot can have only negative values and zero, i.e. address values from 0 to -62 (all of the above-mentioned lowest and highest values included). The use of the relative read address is described more closely in the above-mentioned Finnish Patent Applications which are referred to for a more detailed description. As the multiplexing of tributary unit groups of different levels of hierarchy is based on byte interleaving, columns 19, 22, 25 . . . 268 form the first TU-3 unit, columns 20, 23, 26 . . . 269 form the second TU-3 unit, and columns 21, 24, 27 . . . 270 form the third TU-3 unit, or correspondingly the first, second and third TUG-3 unit, which contains TU-2 and/or TU-12 units (cf. FIG. 3). So, for example, switching instruction words (memory locations) 1, 4, 7, 10, 13 . . . 61 give the switching instruction to the first TU-3 channel, instruction words 2, 5, 8, 11, 14 . . . 62 give it to the second TU-3 channel, and instruction words 3, 6, 9, 12, 15 . . . 63 give it to the third TU-3 channel. FIG. 7 illustrates how the switching instruction words (memory locations) of the address control memory are connected with the different channels in cases where the STM-1 frame contains (i) only TU-12 units, (ii) only TU-2 units, and (iii) only TU-3 units. The address control memory receives information on the phase of the frame from an output 67a of a phase identification circuit 67. A column flag CFLG, which provides information on when columns 1 to 12 are in progress in the frame, is obtained from another output 67b of the phase identification circuit 67. When this flag is valid (during these columns), the output of the address control memory is forced to become zero, i.e. during these columns the adder circuit 65 is not given cross-connection data. On account of the relative address being zero, the data in the columns passes "straight" through the switch (i.e. leaves the switch in the same time slot as it came in). The output of the adder circuit 65 thus has the valve (WA-63), whereas each time slot of the blocks 42 has the value (WA-63+relative read address), in which the relative read address is within a certain range depending on the time slot, as stated above. In addition, the contents of the address control memory must be interpreted at columns 13 to 18 (cf. the above table); i.e. it must be verified whether the switching instruction is reasonable. If other columns than columns 13 to 15 are addressed during these columns, the instruction is not reasonable, and a column relating to any TU-3 signal cannot be concerned. The same applies to columns 16 to 18 as well. If the switching instruction is not reasonable, the null pointer indicator NPI is generated into columns 13 to 15, and correspondingly fixed stuff into columns 16 to 18. If the instruction is a reasonable TU-3 level switching instruction, it may be part of a TU-3 or TU-2 switching instruction, or it may be a TU-12 switching instruction. The column in question can be switched in any case, for if a TU-2 or TU-12 signal is switched by a TU-3-type instruction, it is switched from an incoming TUG-3 unit, which in this case cannot contain a TU-3 signal. Therefore it does not matter if the location of the null pointer indicator should change. FIG. 8 shows an example of the contents of the address control memory when the basic switching block comprises a combination of signals of different levels of hierarchy (which may be of any kind, depending on how a single STM-1 frame can be assembled, cf. FIG. 3). In this case, the same instruction has been copied into each TU-3 channel at intervals of three memory locations, into each TU-2 channel at intervals of 21 memory locations, and each TU-12 channels has only one switching instruction. The solution of the invention can also be used an a space switch 90 shown in FIG. 9. In the example, the space switch has four inputs and four outputs. It is provided with four multiplexer units 91, each of which comprises a 4/1 multiplexer 92 and an address control memory 93. The inputs of each multiplexer 92 are connected to the corresponding input of the space switch (shown in the figure merely with respect to the first multiplexer), and the output of each multiplexer forms one of the outputs of the space switch. Each 4/1 multiplexer is controlled by a separate address control memory 93. In this case, a single address control memory has 63 memory locations, and the switching data are grouped according to FIGS. 7A, 7B and 8. In this case, the most preferable form of a switching instruction is, however, not the relative read address but the absolute address, i.e. the number of the incoming STM-1 signal (the number of the input line), which in this case is from 1 to 4. This number indicates the STM-1 signal the byte of which is switched at that particular moment to the output of the multiplexer. When the STM-1 frame begins, the reading of the switching instruction words is started one time slot at a time. This is continued until the instruction word 18, whereafter the process returns to the beginning, and all the 63 instruction words are read. This is effected four times, whereafter a new STM-1 frame begins. During columns 1 to 12 the switching data is always skipped, i.e. cross-connection is not performed but the data is switched straight through (the bytes of the first input are switched to the first output, the bytes of the second input to the second output, etc.). Information on the phase of the frame is received from a phase identification circuit 94. In the space switch, columns 13 to 18 need not be interpreted as in the case of the time switch, since in the space switch erroneous switching cannot be performed in the same way as in the time switch. As the space switch is known per se, it will not be described here in greater detail. Even though the invention has been described above with reference to the examples shown in the attached drawings, it is obvious that the invention is not restricted to them but may be modified in various ways within the inventive idea disclosed above and in the accompanying claims. Even though the invention has been described with reference to an SDH specific STM-1 signal, the solution of the invention can also be used in connection with any time division multiplex signal. References: [1] CCITT Blue Book, Recommendation G.709: "Synchronous Multiplexing Structure", May 1990. [2] SDH--Ny digital hierarki, TELE 2/90. [3] CCITT Blue Book, Recommendation G.783: "Characteristics of Synchronous Digital Hierarchy (SDH) Multiplexing Equipment Functional Blocks," August 1990, Annex B.

A method for implementing switching in the time or space domain, in which the switching is effected on the basis of switching data contained in an address control memory, and a basic switching block is defined on the basis of an incoming frame structure so that the number of its time slots corresponds to the greatest possible number of signals of the lowest level of hierarchy to be switched in the frame. The basic switching block recurs in the same form with respect to switching. In order for the switching to be simplified: (i) the number of the switching instructions to be stored in the address control memory corresponds to the size of the basic switching block, whereby when the basic switching block also contains higher-level signals, the same switching instruction is used in the address control memory at given intervals, depending on how the signals occur in the basic switching block, (ii) the same address control memory is read during the entire frame structure, whereby it gives a switching instruction to all time slots in the frame, and (iii) the switching instructions read from the address control memory are skipped during the time slots which are not cross-connected.

[0001] The present application claims priority to U.S. Ser. No. 60/396,989 filed May 24, 2002, to U.S. Ser. No. 60/403,868 filed Aug. 14, 2002, to U.S. Ser. No. 60/430,284 filed Dec. 2, 2002, and to U.S. Ser. No. 60/461,175 filed Apr. 8, 2003, the entire contents of each is hereby incorporated by reference. [0002] The present invention relates to rare earth metal compounds, particularly rare earth metal compounds having a porous structure. The present invention also includes methods of making the porous rare earth metal compounds and methods of using the compounds of the present invention. The compounds of the present invention can be used to bind or absorb metals such as arsenic, selenium, antimony and metal ions such as arsenic III + and V + . The compounds of the present invention may therefore find use in water filters or other devices or methods to remove metals and metal ions from fluids, especially water. [0003] The compounds of the present invention are also useful for binding or absorbing anions such as phosphate in the gastrointestinal tract of mammals. Accordingly, one use of the compounds of the present invention is to treat high serum phosphate levels in patients with end-stage renal disease undergoing kidney dialysis. In this aspect, the compounds may be provided in a filter that is fluidically connected with a kidney dialysis machine such that the phosphate content in the blood is reduced after passing through the filter. [0004] In another aspect, the compounds can be used to deliver a lanthanum or other rare-earth metal compound that will bind phosphate present in the gut and prevent its transfer into the bloodstream. Compounds of the present invention can also be used to deliver drugs or to act as a filter or absorber in the gastrointestinal tract or in the blood stream. For example, the materials can be used to deliver inorganic chemicals in the gastrointestinal tract or elsewhere. [0005] It has been found that the porous particle structure and the high surface area are beneficial to high absorption rates of anions. Advantageously, these properties permit the compounds of the present invention to be used to bind phosphate directly in a filtering device fluidically connected with kidney dialysis equipment. [0006] The use of rare earth hydrated oxides, particularly hydrated oxides of La, Ce, and Y to bind phosphate is disclosed in Japanese published patent application 61-004529 (1986). Similarly, U.S. Pat. No. 5,968,976 discloses a lanthanum carbonate hydrate to remove phosphate in the gastrointestinal tract and to treat hyperphosphatemia in patients with renal failure. It also shows that hydrated lanthanum carbonates with about 3 to 6 molecules of crystal water provide the highest removal rates. U.S. Pat. No. 6,322,895 discloses a form of silicon with micron-sized or nano-sized pores that can be used to release drugs slowly in the body. U.S. Pat. No. 5,782,792 discloses a method for the treatment of rheumatic arthritis where a “protein A immunoadsorbent” is placed on silica or another inert binder in a cartridge to physically remove antibodies from the bloodstream. [0007] It has now unexpectedly been found that the specific surface area of compounds according to the present invention as measured by the BET method, varies depending on the method of preparation, and has a significant effect on the properties of the product. As a result, the specific properties of the resulting compound can be adjusted by varying one or more parameters in the method of making the compound. In this regard, the compounds of the present invention have a BET specific surface area of at least about 10 m 2 /g and may have a BET specific surface area of at least about 20 m 2 /g and alternatively may have a BET specific surface area of at least about 35 m 2 /g. In one embodiment, the compounds have a BET specific surface area within the range of about 10 m 2 /g and about 40 m 2 /g. [0008] It has also been found that modifications in the preparation method of the rare earth compounds will create different entities, e.g. different kinds of hydrated or amorphous oxycarbonates rather than carbonates, and that these compounds have distinct and improved properties. It has also been found that modifications of the preparation method create different porous physical structures with improved properties. [0009] The compounds of the present invention and in particular, the lanthanum compounds and more particularly the lanthanum oxycarbonates of the present invention exhibit phosphate binding or removal of at least 40% of the initial concentration of phosphate after ten minutes. Desirably, the lanthanum compounds exhibit phosphate binding or removal of at least 60% of the initial concentration of phosphate after ten minutes. In other words, the lanthanum compounds and in particular, the lanthanum compounds and more particularly the lanthanum oxycarbonates of the present invention exhibit a phosphate binding capacity of at least 45 mg of phosphate per gram of lanthanum compound. Suitably, the lanthanum compounds exhibit a phosphate binding capacity of at least 50 mg PO 4 /g of lanthanum compound, more suitably, a phosphate binding capacity of at least 75 mg PO 4 /g of lanthanum compound. Desirably, the lanthanum compounds exhibit a phosphate binding capacity of at least 100 mg PO 4 /g of lanthanum compound, more desirably, a phosphate binding capacity of at least 110 mg PO 4 /g of lanthanum compound. [0010] In accordance with the present invention, rare earth metal compounds, and in particular, rare earth metal oxychlorides and oxycarbonates are provided. The oxycarbonates may be hydrated or anhydrous. These compounds may be produced according to the present invention as particles having a porous structure. The rare earth metal compound particles of the present invention may conveniently be produced within a controllable range of surface areas with resultant variable and controllable adsorption rates of ions. [0011] The porous particles or porous structures of the present invention are made of nano-sized to micron-sized crystals with controllable surface areas. The rare earth oxychloride is desirably lanthanum oxychloride (LaOCl). The rare earth oxycarbonate hydrate is desirably lanthanum oxycarbonate hydrate (La 2 O(CO 3 ) 2 .xH 2 O where x is from and including 2 to and including 4). This compound will further be referred to in this text as La 2 O(CO 3 ) 2 .xH 2 O. The anhydrous rare earth oxycarbonate is desirably lanthanum oxycarbonate La 2 O 2 CO 3 or La 2 CO 5 of which several crystalline forms exist. The lower temperature form will be identified as La 2 O 2 CO 3 and the form obtained at higher temperature or after a longer calcination time will be identified as La 2 CO 5 . [0012] One skilled in the art, however, will understand that lanthanum oxycarbonate may be present as a mixture of the hydrate and the anhydrous form. In addition, the anhydrous lanthanum oxycarbonate may be present as a mixture of La 2 O 2 CO 3 and La 2 CO 5 and may be present in more than a single crystalline form. [0013] One method of making the rare earth metal compound particles includes making a solution of rare earth metal chloride, subjecting the solution to a substantially total evaporation process using a spray dryer or other suitable equipment to form an intermediate product, and calcining the obtained intermediate product at a temperature between about 500° and about 1200° C. The product of the calcination step may be washed, filtered, and dried to make a suitable finished product. Optionally, the intermediate product may be milled in a horizontal or vertical pressure media mill to a desired surface area and then further spray dried or dried by other means to produce a powder that may be further washed and filtered. [0014] An alternative method of making the rare earth metal compounds, particularly rare earth metal anhydrous oxycarbonate particles includes making a solution of rare earth metal acetate, subjecting the solution to a substantially total evaporation process using a spray dryer or other suitable equipment to make an intermediate product, and calcining the obtained intermediate product at a temperature between about 400° C. and about 700° C. The product of the calcination step may be washed, filtered, and dried to make a suitable finished product. Optionally, the intermediate product may be milled in a horizontal or vertical pressure media mill to a desired surface area, spray dried or dried by other means to produce a powder that may be washed, filtered, and dried. [0015] Yet another method of making the rare earth metal compounds includes making rare earth metal oxycarbonate hydrate particles. The rare earth metal oxycarbonate hydrate particles can be made by successively making a solution of rare earth chloride, subjecting the solution to a slow, steady feed of a sodium carbonate solution at a temperature between about 30° and about 90° C. while mixing, then filtering and washing the precipitate to form a filter cake, then drying the filter cake at a temperature of about 1000 to 120° C. to produce the desired rare earth oxycarbonate hydrate species. Optionally, the filter cake may be sequentially dried, slurried, and milled in a horizontal or vertical pressure media mill to a desired surface area, spray dried or dried by other means to produce a powder that may be washed, filtered, and dried. [0016] Alternatively, the process for making rare earth metal oxycarbonate hydrate particles may be modified to produce anhydrous particles. This modification includes subjecting the dried filter cake to a thermal treatment at a specified temperature between about 400° C. to about 700° C. and for a specified time between 1 h and 48 h. Optionally, the product of the thermal treatment may be slurried and milled in a horizontal or vertical pressure media mill to a desired surface area, spray dried or dried by other means to produce a powder that may be washed, filtered, and dried. [0017] In accordance with the present invention, compounds of the present invention may be used to treat patients with hyperphosphatemia. The compounds may be made into a form that may be delivered to a mammal and that may be used to remove phosphate from the gut or decrease phosphate absorption into the blood stream. For example, the compounds may be formulated to provide an orally ingestible form such as a liquid solution or suspension, a tablet, capsule, gelcap, or other suitable and known oral form. Accordingly, the present invention contemplates a method for treating hyperphosphatemia that comprises providing an effective amount of a compound of the present invention. Compounds made under different conditions will correspond to different oxycarbonates or oxychlorides, will have different surface areas, and will show differences in reaction rates with phosphate and different solubilization of lanthanum or another rare-earth metal into the gut. The present invention allows one to modify these properties according to the requirements of the treatment. [0018] In another aspect of the present invention, compounds made according to this invention as a porous structure of sufficient mechanical strength may be placed in a device fluidically connected to a dialysis machine through which the blood flows, to directly remove phosphate by reaction of the rare-earth compound with phosphate in the bloodstream. The present invention therefore contemplates a device having an inlet and an outlet with one or more compounds of the present invention disposed between the inlet and the outlet. The present invention also contemplates a method of reducing the amount of phosphate in blood that comprises contacting the blood with one or more compounds of the present invention for a time sufficient to reduce the amount of phosphate in the blood. [0019] In yet another aspect of the present invention, the compounds of the present invention may be used as a substrate for a filter having an inlet and outlet such that the compounds of the present invention are disposed between the inlet and the outlet. A fluid containing a metal, metal ion, phosphate or other ion may be passed from the inlet to contact the compounds of the present invention and through the outlet. Accordingly, in one aspect of the present invention a method of reducing the content of a metal in a fluid, for example water, comprises flowing the fluid through a filter that contains one or more compounds of the present invention to reduce the amount of metal present in the water. BRIEF DESCRIPTION OF THE DRAWINGS [0020] FIG. 1 is a general flow sheet of a process according to the present invention that produces LaOCl (lanthanum oxychloride). [0021] FIG. 2 is a flow sheet of a process according to the present invention that produces a coated titanium dioxide structure. [0022] FIG. 3 is a flow sheet of a process according to the present invention that produces lanthanum oxycarbonate [0023] FIG. 4 is a graph showing the percentage of phosphate removed from a solution as a function of time by LaO(CO 3 ) 2 .x H 2 O, (where x is from and including 2 to and including 4), made according to the process of the present invention, as compared to the percentage of phosphate removed by commercial grade La carbonate La 2 (CO 3 ) 3 .4H 2 O in the same conditions. [0024] FIG. 5 is a graph showing the amount of phosphate removed from a solution as a function of time per g of a lanthanum compound used as a drug to treat hyperphosphatemia. The drug in one case is La 2 O(CO 3 ) 2 .x H 2 O (where x is from and including 2 to and including 4), made according to the process of the present invention. In the comparative case the drug is commercial grade La carbonate La 2 (CO 3 ) 3 .4H 2 O. [0025] FIG. 6 is a graph showing the amount of phosphate removed from a solution as a function of time per g of a lanthanum compound used as a drug to treat hyperphosphatemia. The drug in one case is La 2 O 2 CO 3 made according to the process of the present invention. In the comparative case the drug is commercial grade La carbonate La 2 (CO 3 ) 3 .4H 2 O. [0026] FIG. 7 is a graph showing the percentage of phosphate removed as a function of time by La 2 O 2 CO 3 made according to the process of the present invention, as compared to the percentage of phosphate removed by commercial grade La carbonate La 2 (CO 3 ) 3 .4H 2 O. [0027] FIG. 8 is a graph showing a relationship between the specific surface area of the oxycarbonates made following the process of the present invention and the amount of phosphate bound or removed from solution 10 min after the addition of the oxycarbonate. [0028] FIG. 9 is a graph showing a linear relationship between the specific surface area of the oxycarbonates of this invention and the first order rate constant calculated from the initial rate of reaction of phosphate. [0029] FIG. 10 is a flow sheet of a process according to the present invention that produces lanthanum oxycarbonate hydrate La 2 (CO 3 ) 2 .xH 2 O [0030] FIG. 11 is a flow sheet of a process according to the present invention that produces anhydrous lanthanum oxycarbonate La 2 O 2 CO 3 or La 2 CO 5 . [0031] FIG. 12 is a scanning electron micrograph of lanthanum oxychloride, made following the process of the present invention. [0032] FIG. 13 is an X-Ray diffraction scan of lanthanum oxychloride LaOCl made according to the process of the present invention and compared with a standard library card of lanthanum oxychloride. [0033] FIG. 14 is a graph showing the percentage of phosphate removed from a solution as a function of time by LaOCl made according to the process of the present invention, as compared to the amount of phosphate removed by commercial grades of La carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O in the same conditions. [0034] FIG. 15 shows a scanning electron micrograph of La 2 O(CO 3 ) 2 .x H 2 O, where x is from and including 2 to and including 4. [0035] FIG. 16 is an X-Ray diffraction scan of La 2 O(CO 3 ) 2 .x H 2 O produced according to the present invention and includes a comparison with a “library standard” of La 2 O(CO 3 ) 2 .xH 2 O where x is from and including 2 to and including 4. [0036] FIG. 17 is a graph showing the rate of removal of phosphorous from a solution by La 2 O(CO 3 ) 2 .xH 2 O compared to the rate obtained with commercially available La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O in the same conditions. [0037] FIG. 18 is a scanning electron micrograph of anhydrous lanthanum oxycarbonate La 2 O 2 CO 3 . [0038] FIG. 19 is an X-Ray diffraction scan of anhydrous La 2 O 2 CO 3 produced according to the present invention and includes a comparison with a “library standard” of La 2 O 2 CO 3 . [0039] FIG. 20 is a graph showing the rate of phosphorous removal obtained with La 2 O 2 CO 3 made following the process of the present invention and compared to the rate obtained for commercially available La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O. [0040] FIG. 21 is a scanning electron micrograph of La 2 CO 5 made according to the process of the present invention. [0041] FIG. 22 is an X-Ray diffraction scan of anhydrous La 2 CO 5 produced according to the present invention and includes a comparison with a “library standard” of La 2 CO 5 . [0042] FIG. 23 is a graph showing the rate of phosphorous removal obtained with La 2 CO 5 made following the process of the present invention and compared to the rate obtained for commercially available La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O. [0043] FIG. 24 is a scanning electron micrograph of TiO 2 support material made according to the process of the present invention. [0044] FIG. 25 is a scanning electron micrograph of a TiO 2 structure coated with LaOCl, made according to the process of the present invention, calcined at 800° C. [0045] FIG. 26 is a scanning electron micrograph of a TiO 2 structure coated with LaOCl, made according to the process of the present invention, calcined at 600° C. [0046] FIG. 27 is a scanning electron micrograph of a TiO 2 structure coated with LaOCl, made according to the process of the present invention, calcined at 900° C. [0047] FIG. 28 . shows X-Ray scans for TiO 2 coated with LaOCl and calcined at different temperatures following the process of the present invention, and compared to the X-Ray scan for pure LaOCl. [0048] FIG. 29 shows the concentration of lanthanum in blood plasma as a function of time, for dogs treated with lanthanum oxycarbonates made according to the process of the present invention. [0049] FIG. 30 shows the concentration of phosphorous in urine as a function of time in rats treated with lanthanum oxycarbonates made according to the process of the present invention, and compared to phosphorus concentration measured in untreated rats. [0050] FIG. 31 shows a device having an inlet, an outlet, and one or more compounds of the present invention disposed between the inlet and the outlet. DESCRIPTION OF THE INVENTION [0051] Referring now to the drawings, the process of the present invention will be described. While the description will generally refer to lanthanum compounds, the use of lanthanum is merely for ease of description and is not intended to limit the invention and claims solely to lanthanum compounds. In fact, it is contemplated that the process and the compounds described in the present specification is equally applicable to rare earth metals other than lanthanum such as Ce and Y. [0052] Turning now to FIG. 1 , a process for making a rare earth oxychloride compound, and, in particular a lanthanum oxychloride compound according to one embodiment of the present invention is shown. First, a solution of lanthanum chloride is provided. The source of lanthanum chloride may be any suitable source and is not limited to any particular source. One source of lanthanum chloride solution is to dissolve commercial lanthanum chloride crystals in water or in an HCl solution. Another source is to dissolve lanthanum oxide in a hydrochloric acid solution. [0053] The lanthanum chloride solution is evaporated to form an intermediate product. The evaporation 20 is conducted under conditions to achieve substantially total evaporation. Desirably, the evaporation is conducted at a temperature higher than the boiling point of the feed solution (lanthanum chloride) but lower than the temperature where significant crystal growth occurs. The resulting intermediate product may be an amorphous solid formed as a thin film or may have a spherical shape or a shape as part of a sphere. [0054] The terms “substantially total evaporation” or “substantially complete evaporation” as used in the specification and claims refer to evaporation such that the resulting solid intermediate contains less than 15% free water, desirably less than 10% free water, and more desirably less than 1% free water. The term “free water” is understood and means water that is not chemically bound and can be removed by heating at a temperature below 150° C. After substantially total evaporation or substantially complete evaporation, the intermediate product will have no visible moisture present. [0055] The evaporation step may be conducted in a spray dryer. In this case, the intermediate product will consist of a structure of spheres or parts of spheres. The spray dryer generally operates at a discharge temperature between about 120° C. and about 500° C. [0056] The intermediate product may then be calcined in any suitable calcination apparatus 30 by raising the temperature to a temperature between about 500° C. to about 1200° C. for a period of time from about 2 to about 24 h and then cooling to room temperature. The cooled product may be washed 40 by immersing it in water or dilute acid, to remove any water-soluble phase that may still be present after the calcination step 30 . [0057] The temperature and the length of time of the calcination process may be varied to adjust the particle size and the reactivity of the product. The particles resulting from calcination generally have a size between 1 and 1000 μm. The calcined particles consist of individual crystals, bound together in a structure with good physical strength and a porous structure. The individual crystals forming the particles generally have a size between 20 nm and 10 μm. [0058] In accordance with another embodiment of the present invention as shown in FIG. 2 , a feed solution of titanium chloride or titanium oxychloride is provided by any suitable source. One source is to dissolve anhydrous titanium chloride in water or in a hydrochloric acid solution. Chemical control agents or additives 104 may be introduced to this feed solution to influence the crystal form and the particle size of the final product. One chemical additive is sodium phosphate Na 3 PO 4 . The feed solution of titanium chloride or titanium oxychloride is mixed with the optional chemical control agent 104 in a suitable mixing step 110 . The mixing may be conducted using any suitable known mixer. [0059] The feed solution is evaporated to form an intermediate product, which in this instance is titanium dioxide (TiO 2 ). The evaporation 120 is conducted at a temperature higher than the boiling point of the feed solution but lower than the temperature where significant crystal growth occurs and to achieve substantially total evaporation. The resulting intermediate product may desirably be an amorphous solid formed as a thin film and may have a spherical shape or a shape as part of a sphere. [0060] The intermediate product may then be calcined in any suitable calcination apparatus 130 by raising the temperature to a temperature between about 400° C. to about 1200° C. for a period of time from about 2 to about 24 h and then cooling to room temperature (25° C.). The cooled product is then washed 140 by immersing it in water or dilute acid, to remove traces of any water-soluble phase that may still be present after the calcination step. [0061] The method of manufacture of the intermediate product according to the present invention can be adjusted and chosen to make a structure with the required particle size and porosity. For example, the evaporation step 120 and the calcination step 130 can be adjusted for this purpose. The particle size and porosity can be adjusted to make the structure of the intermediate product suitable to be used as an inert filter in the bloodstream. [0062] The washed TiO 2 product is then suspended or slurried in a solution of an inorganic compound. A desirable inorganic compound is a rare-earth or lanthanum compound, and in particular lanthanum chloride. This suspension of TiO 2 in the inorganic compound solution is again subjected to total evaporation 160 under conditions in the same range as defined in step 120 and to achieve substantially total evaporation. In this regard, the evaporation steps 120 and 160 may be conducted in a spray drier. The inorganic compound will precipitate as a salt, an oxide, or an oxy-salt. If the inorganic compound is lanthanum chloride, the precipitated product will be lanthanum oxychloride. If the original compound is lanthanum acetate, the precipitated product will be lanthanum oxide. [0063] The product of step 160 is further calcined 170 at a temperature between 5000 and 1100° C. for a period of 2 to 24 h. The temperature and the time of the calcination process influence the properties and the particle size of the product. After the second calcination step 170 , the product may be washed 180 . [0064] The resulting product can be described as crystals of lanthanum oxychloride or lanthanum oxide formed on a TiO 2 substrate. The resulting product may be in the form of hollow thin-film spheres or parts of spheres. The spheres will have a size of about 1 μm to 1000 μm and will consist of a structure of individual bound particles. The individual particles have a size between 20 nm and 10 μm. [0065] When the final product consists of crystals of lanthanum oxychloride on a TiO 2 substrate, these crystals may be hydrated. It has been found that this product will effectively react with phosphate and bind it as an insoluble compound. It is believed that, if this final product is released in the human stomach and gastrointestinal tract, the product will bind the phosphate that is present and decrease the transfer of phosphate from the stomach and gastrointestinal tract to the blood stream. Therefore, the product of this invention may be used to limit the phosphorous content in the bloodstream of patients on kidney dialysis. [0066] According to another embodiment of the present invention, a process for making anhydrous lanthanum oxycarbonate is shown in FIG. 3 . In this process, a solution of lanthanum acetate is made by any method. One method to make the lanthanum acetate solution is to dissolve commercial lanthanum acetate crystals in water or in an HCl solution. [0067] The lanthanum acetate solution is evaporated to form an intermediate product. The evaporation 220 is conducted at a temperature higher than the boiling point of the lanthanum acetate solution but lower than the temperature where significant crystal growth occurs and under conditions to achieve substantially total evaporation. The resulting intermediate product may desirably be an amorphous solid formed as a thin film and may have a spherical shape or a shape as part of a sphere. [0068] The intermediate product may then be calcined in any suitable calcination apparatus 230 by raising the temperature to a temperature between about 400° C. to about 800° C. for a period of time from about 2 to about 24 h and then cooled to room temperature. The cooled product may be washed 240 by immersing it in water or dilute acid, to remove any water-soluble phase that may still be present after the calcination step. The temperature and the length of time of the calcination process may be varied to adjust the particle size and the reactivity of the product. [0069] The particles resulting from the calcination generally have a size between 1 and 1000 μm. The calcined particles consist of individual crystals, bound together in a structure with good physical strength and a porous structure. The individual crystals generally have a size between 20 nm and 10 μm. [0070] The products made by methods shown in FIGS. 1, 2 , and 3 comprise ceramic particles with a porous structure. Individual particles are in the micron size range. The particles are composed of crystallites in the nano-size range, fused together to create a structure with good strength and porosity. [0071] The particles made according to the process of the present invention, have the following common properties: a. They have low solubility in aqueous solutions, especially serum and gastro-intestinal fluid, compared to non-ceramic compounds. b. Their hollow shape gives them a low bulk density compared to solid particles. Lower density particles are less likely to cause retention in the gastro-intestinal tract. c. They have good phosphate binding kinetics. The observed kinetics are generally better than the commercial carbonate hydrates La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O. In the case of lanthanum oxychloride, the relationship between the amount of phosphate bound or absorbed and time tends to be closer to linear than for commercial hydrated lanthanum carbonates. The initial reaction rate is lower but does not significantly decrease with time over an extended period. This behavior is defined as linear or substantially linear binding kinetics. This is probably an indication of more selective phosphate binding in the presence of other anions. d. Properties a, b, and c, above are expected to lead to less gastro-intestinal tract complications than existing products. e. Because of their particular structure and low solubility, the products of the present invention have the potential to be used in a filtration device placed directly in the bloodstream. [0077] Different lanthanum oxycarbonates have been prepared by different methods. It has been found that, depending on the method of preparation, lanthanum oxycarbonate compounds with widely different reaction rates are obtained. [0078] A desirable lanthanum oxycarbonate is La 2 O(CO 3 ) 2 .xH 2 O, where 2≦x≦4. This lanthanum oxycarbonate is preferred because it exhibits a relatively high rate of removal of phosphate. To determine the reactivity of the lanthanum oxycarbonate compound with respect to phosphate, the following procedure was used. A stock solution containing 13.75 g/l of anhydrous Na 2 HPO 4 and 8.5 g/l of HCl is prepared. The stock solution is adjusted to pH 3 by the addition of concentrated HCl. 100 ml of the stock solution is placed in a beaker with a stirring bar. A sample of lanthanum oxycarbonate powder is added to the solution. The amount of lanthanum oxycarbonate powder is such that the amount of La in suspension is 3 times the stoichiometric amount needed to react completely with the phosphate. Samples of the suspension are taken at intervals, through a filter that separated all solids from the liquid. The liquid sample is analyzed for phosphorous. FIG. 4 shows that after 10 min, La 2 O(CO 3 ) 2 .xH 2 O has removed 86% of the phosphate in solution, whereas a commercial hydrated La carbonate La 2 (CO 3 ) 3 .4H 2 O removes only 38% of the phosphate in the same experimental conditions after the same time. [0079] FIG. 5 shows that the La 2 O(CO 3 ) 2 .xH 2 O depicted in FIG. 4 has a capacity of phosphate removal of 110 mg PO 4 removed/g of La compound after 10 min in the conditions described above, compared to 45 mg PO 4 /g for the commercial La carbonate taken as reference. [0080] Another preferred lanthanum carbonate is the anhydrous La oxycarbonate La 2 O 2 CO 3 . This compound is preferred because of its particularly high binding capacity for phosphate, expressed as mg PO 4 removed/g of compound. FIG. 6 shows that La 2 O 2 CO 3 binds 120 mg PO 4 /g of La compound after 10 min, whereas La 2 (CO 3 ) 3 .4H 2 O used as reference only binds 45 mg PO 4 /g La compound. [0081] FIG. 7 shows the rate of reaction with phosphate of the oxycarbonate La 2 O 2 CO 3 . After 10 min of reaction, 73% of the phosphate had been removed, compared to 38% for commercial lanthanum carbonate used as reference. [0082] Samples of different oxycarbonates have been made by different methods as shown in Table 1 below. TABLE 1 Initial Example number BET Fraction of 1st order corresponding to surface PO 4 rate constant manufacturing area remaining k 1 Sample Compound method m 2 /g after 10 min (min −1 ) 1 La 2 O(CO 3 ) 2 . x H 2 O 11  41.3 0.130 0.949 2 La 2 O(CO 3 ) 2 . x H 2 O 11  35.9 0.153 0.929 3 La 2 O(CO 3 ) 2 . x H 2 O 11  38.8 0.171 0.837 4 La 2 CO 5 (4 h milling) 7 25.6 0.275 0.545 5 La 2 O 2 CO 3 5 18 0.278 0.483 6 La 2 CO 5 (2 h milling) 7 18.8 0.308 0.391 7 La 2 O 2 CO 3 7 16.5 0.327 0.36 8 La 2 CO 5 (no milling) 5 11.9 0.483 0.434 9 La 2 (CO 3 ) 3 .4H 2 O commercial 4.3 0.623 0.196 sample 10 La 2 (CO 3 ) 3 .1H 2 O commercial 2.9 0.790 0.094 sample [0083] For each sample, the surface area measured by the BET method and the fraction of phosphate remaining after 10 min of reaction have been tabulated. The table also shows the rate constant k 1 corresponding to the initial rate of reaction of phosphate, assuming the reaction is first order in phosphate concentration. The rate constant k 1 is defined by the following equation: d [PO 4 ]/dt=−k 1 [PO 4 ] where [PO 4 ] is the phosphate concentration in solution (mol/liter), t is time (min) and k 1 is the first order rate constant (min −1 ). The table gives the rate constant for the initial reaction rate, i.e. the rate constant calculated from the experimental points for the first minute of the reaction. [0084] FIG. 8 shows that there is a good correlation between the specific surface area and the amount of phosphate reacted after 10 min. It appears that in this series of tests, the most important factor influencing the rate of reaction is the surface area, independently of the composition of the oxycarbonate or the method of manufacture. A high surface area can be achieved by adjusting the manufacturing method or by milling a manufactured product. [0085] FIG. 9 shows that a good correlation is obtained for the same compounds by plotting the first order rate constant as given in Table 1 and the BET specific surface area. The correlation can be represented by a straight line going through the origin. In other words, within experimental error, the initial rate of reaction appears to be proportional to the phosphate concentration and also to the available surface area. [0086] Without being bound by any theory, it is proposed that the observed dependence on surface area and phosphate concentration may be explained by a nucleophilic attack of the phosphate ion on the La atom in the oxycarbonate, with resultant formation of lanthanum phosphate LaPO 4 . For example, if the oxycarbonate is La 2 O 2 CO 3 , the reaction will be: ½ La 2 O 2 CO 3 +PO 4 3− +2H 2 O→LaPO 4 +½ H 2 CO 3 +3OH − If the rate is limited by the diffusion of the PO 4 3− ion to the surface of the oxycarbonate and the available area of oxycarbonate, the observed relationship expressed in FIG. 9 can be explained. This mechanism does not require La to be present as a dissolved species. The present reasoning also provides an explanation for the decrease of the reaction rate after the first minutes: the formation of lanthanum phosphate on the surface of the oxycarbonate decreases the area available for reaction. [0087] In general, data obtained at increasing pH show a decrease of the reaction rate. This may be explained by the decrease in concentration of the hydronium ion (H 3 O + ), which may catalyze the reaction by facilitating the formation of the carbonic acid molecule from the oxycarbonate. [0088] Turning now to FIG. 10 , another process for making lanthanum oxycarbonate and in particular, lanthanum oxycarbonate tetra hydrate, is shown. First, an aqueous solution of lanthanum chloride is made by any method. One method to make the solution is to dissolve commercial lanthanum chloride crystals in water or in an HCl solution. Another method to make the lanthanum chloride solution is to dissolve lanthanum oxide in a hydrochloric acid solution. [0089] The LaCl 3 solution is placed in a well-stirred tank reactor. The LaCl 3 solution is then heated to 80° C. A previously prepared analytical grade sodium carbonate is steadily added over a period of 2 hours with vigorous mixing. The mass of sodium carbonate required is calculated at 6 moles of sodium carbonate per 2 moles of LaCl 3 . When the required mass of sodium carbonate solution is added, the resultant slurry or suspension is allowed to cure for 2 hours at 80° C. The suspension is then filtered and washed with demineralized water to produce a clear filtrate. The filter cake is placed in a convection oven at 105° C. for 2 hours or until a stable weight is observed. The initial pH of the LaCl 3 solution is 2, while the final pH of the suspension after cure is 5.5. A white powder is produced. The resultant powder is a lanthanum oxycarbonate four hydrate (La 2 O(CO 3 ) 2 .xH 2 O). The number of water molecules in this compound is approximate and may vary between 2 and 4 (and including 2 and 4). [0090] Turning now to FIG. 11 another process for making anhydrous lanthanum oxycarbonate is shown. First, an aqueous solution of lanthanum chloride is made by any method. One method to make the solution is to dissolve commercial lanthanum chloride crystals in water or in an HCl solution. Another method to make the lanthanum chloride solution is to dissolve lanthanum oxide in a hydrochloric acid solution. [0091] The LaCl 3 solution is placed in a well-stirred tank reactor. The LaCl 3 solution is then heated to 80° C. A previously prepared analytical grade sodium carbonate is steadily added over 2 hours with vigorous mixing. The mass of sodium carbonate required is calculated at 6 moles of sodium carbonate per 2 moles of LaCl 3 . When the required mass of sodium carbonate solution is added the resultant slurry or suspension is allowed to cure for 2 hours at 80° C. The suspension is then washed and filtered removing NaCl (a byproduct of the reaction) to produce a clear filtrate. The filter cake is placed in a convection oven at 105° C. for 2 hours or until a stable weight is observed. The initial pH of the LaCl 3 solution is 2.2, while the final pH of the suspension after cure is 5.5. A white lanthanum oxycarbonate hydrate powder is produced. Next the lanthanum oxycarbonate hydrate is placed in an alumina tray, which is placed in a high temperature muffle furnace. The white powder is heated to 500° C. and held at that temperature for 3 hours. Anhydrous La 2 C 2 O 3 is formed. [0092] Alternatively, the anhydrous lanthanum oxycarbonate formed as indicated in the previous paragraph may be heated at 500° C. for 15 to 24 h instead of 3 h or at 600° C. instead of 500° C. The resulting product has the same chemical formula, but shows a different pattern in an X-Ray diffraction scan and exhibits a higher physical strength and a lower surface area. The product corresponding to a higher temperature or a longer calcination time is defined here as La 2 CO 5 . [0093] Turning now to FIG. 31 , a device 500 having an inlet 502 and an outlet 504 is shown. The device 500 may be in the form of a filter or other suitable container. Disposed between the inlet 502 and the outlet 504 is a substrate 506 in the form of a plurality of one or more compounds of the present invention. The device may be fluidically connected to a dialysis machine through which the blood flows, to directly remove phosphate by reaction of the rare-earth compound with phosphate in the bloodstream. In this connection, the present invention also contemplates a method of reducing the amount of phosphate in blood that comprises contacting the blood with one or more compounds of the present invention for a time sufficient to reduce the amount of phosphate in the blood. [0094] In yet another aspect of the present invention, the device 500 may be provided in a fluid stream so that a fluid containing a metal, metal ion, phosphate or other ion may be passed from the inlet 502 through the substrate 506 to contact the compounds of the present invention and out the outlet 504 . Accordingly, in one aspect of the present invention a method of reducing the content of a metal in a fluid, for example water, comprises flowing the fluid through a device 500 that contains one or more compounds of the present invention to reduce the amount of metal present in the water. [0095] The following examples are meant to illustrate but not limit the present invention. EXAMPLE 1 [0096] An aqueous solution containing 100 g/l of La as lanthanum chloride is injected in a spray dryer with an outlet temperature of 250° C. The intermediate product corresponding to the spray-drying step is recovered in a bag filter. This intermediate product is calcined at 900° C. for 4 hours. FIG. 12 shows a scanning electron micrograph of the product, enlarged 25,000 times. The micrograph shows a porous structure formed of needle-like particles. The X-Ray diffraction pattern of the product ( FIG. 13 ) shows that it consists of lanthanum oxychloride LaOCl. [0097] To determine the reactivity of the lanthanum compound with respect to phosphate, the following test was conducted. A stock solution containing 13.75 g/l of anhydrous Na 2 HPO 4 and 8.5 g/l of HCl was prepared. The stock solution was adjusted to pH 3 by the addition of concentrated HCl. An amount of 100 ml of the stock solution was placed in a beaker with a stirring bar. The lanthanum oxychloride from above was added to the solution to form a suspension. The amount of lanthanum oxychloride was such that the amount of La in suspension was 3 times the stoichiometric amount needed to react completely with the phosphate. Samples of the suspension were taken at time intervals, through a filter that separated all solids from the liquid. The liquid sample was analyzed for phosphorous. FIG. 14 shows the rate of phosphate removed from solution. EXAMPLE 2 (COMPARATIVE EXAMPLE) [0098] To determine the reactivity of a commercial lanthanum with respect to phosphate, the relevant portion of Example I was repeated under the same conditions, except that commercial lanthanum carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .H 2 O was used instead of the lanthanum oxychloride of the present invention. Additional curves on FIG. 14 show the rate of removal of phosphate corresponding to commercial lanthanum carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ).4H 2 O. FIG. 14 shows that the rate of removal of phosphate with the commercial lanthanum carbonate is faster at the beginning but slower after about 3 minutes. EXAMPLE 3 [0099] An aqueous HCl solution having a volume of 334.75 ml and containing LaCl 3 (lanthanum chloride) at a concentration of 29.2 wt % as La 2 O 3 was added to a four liter beaker and heated to 80° C. with stirring. The initial pH of the LaCl 3 solution was 2.2. Two hundred and sixty five ml of an aqueous solution containing 63.59 g of sodium carbonate (Na 2 CO 3 ) was metered into the heated beaker using a small pump at a steady flow rate for 2 hours. Using a Buchner filtering apparatus fitted with filter paper, the filtrate was separated from the white powder product. The filter cake was mixed four times with 2 liters of distilled water and filtered to wash away the NaCl formed during the reaction. The washed filter cake was placed into a convection oven set at 105° C. for 2 hours, or until a stable weight was observed. FIG. 15 shows a scanning electron micrograph of the product, enlarged 120,000 times. The micrograph shows the needle-like structure of the compound. The X-Ray diffraction pattern of the product ( FIG. 16 ) shows that it consists of hydrated lanthanum oxycarbonate hydrate (La 2 O(CO 3 ) 2 .xH 2 O), with 2≦x≦4. [0100] To determine the reactivity of the lanthanum compound with respect to phosphate, the following test was conducted. A stock solution containing 13.75 g/l of anhydrous Na 2 HPO 4 and 8.5 gA of HCl was prepared. The stock solution was adjusted to pH 3 by the addition of concentrated HCl. An amount of 100 ml of the stock solution was placed in a beaker with a stirring bar. Lanthanum oxycarbonate hydrate powder made as described above was added to the solution. The amount of lanthanum oxycarbonate hydrate powder was such that the amount of La in suspension was 3 times the stoichiometric amount needed to react completely with the phosphate. Samples of the suspension were taken at time intervals through a filter that separated all solids from the liquid. The liquid sample was analyzed for phosphorous. FIG. 17 shows the rate of phosphate removed from solution. EXAMPLE 4 (COMPARATIVE EXAMPLE) [0101] To determine the reactivity of a commercial lanthanum with respect to phosphate, the second part of Example 3 was repeated under the same conditions, except that commercial lanthanum carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O was used instead of the lanthanum oxychloride of the present invention. FIG. 17 shows the rate of phosphate removed using the commercial lanthanum carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O. FIG. 17 shows that the rate of removal of phosphate with the lanthanum oxycarbonate is faster than with the commercial lanthanum carbonate hydrate (La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O). EXAMPLE 5 [0102] An aqueous HCl solution having a volume of 334.75 ml and containing LaCl 3 (lanthanum chloride) at a concentration of 29.2 wt % as La 2 O 3 was added to a 4 liter beaker and heated to 80° C. with stirring. The initial pH of the LaCl 3 solution was 2.2. Two hundred and sixty five ml of an aqueous solution containing 63.59 g of sodium carbonate (Na 2 CO 3 ) was metered into the heated beaker using a small pump at a steady flow rate for 2 hours. Using a Buchner filtering apparatus fitted with filter paper the filtrate was separated from the white powder product. The filter cake was mixed four times with 2 liters of distilled water and filtered to wash away the NaCl formed during the reaction. The washed filter cake was placed into a convection oven set at 105° C. for 2 hours until a stable weight was observed. Finally, the lanthanum oxycarbonate was placed in an alumina tray in a muffle furnace. The furnace temperature was ramped to 500° C. and held at that temperature for 3 hours. The resultant product was determined to be anhydrous lanthanum oxycarbonate La 2 O 2 CO 3 . [0103] The process was repeated three times. In one case, the surface area of the white powder was determined to be 26.95 m 2 /gm. In the other two instances, the surface area and reaction rate is shown in Table 1. FIG. 18 is a scanning electron micrograph of the structure, enlarged 60,000 times. The micrograph shows that the structure in this compound is made of equidimensional or approximately round particles of about 100 nm in size. FIG. 19 is an X-ray diffraction pattern showing that the product made here is an anhydrous lanthanum oxycarbonate written as La 2 O 2 CO 3 . [0104] To determine the reactivity of this lanthanum compound with respect to phosphate, the following test was conducted. A stock solution containing 13.75 g/l of anhydrous Na 2 HPO 4 and 8.5 g/l of HCl was prepared. The stock solution was adjusted to pH 3 by the addition of concentrated HCl. An amount of 100 ml of the stock solution was placed in a beaker with a stirring bar. Anhydrous lanthanum oxycarbonate made as described above, was added to the solution. The amount of anhydrous lanthanum oxycarbonate was such that the amount of La in suspension was 3 times the stoichiometric amount needed to react completely with the phosphate. Samples of the suspension were taken at intervals, through a filter that separated all solids from the liquid. The liquid sample was analyzed for phosphorous. FIG. 20 shows the rate of phosphate removed. EXAMPLE 6 (COMPARATIVE EXAMPLE) [0105] To determine the reactivity of a commercial lanthanum with respect to phosphate, the second part of Example 5 was repeated under the same conditions, except that commercial lanthanum carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O was used instead of the La 2 O 2 CO 3 of the present invention. FIG. 20 shows the rate of removal of phosphate using the commercial lanthanum carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O. FIG. 20 shows that the rate of removal of phosphate with the anhydrous lanthanum oxycarbonate produced according to the process of the present invention is faster than the rate observed with commercial lanthanum carbonate hydrate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 30.4 H 2 O. EXAMPLE 7 [0106] A solution containing 100 g/l of La as lanthanum acetate is injected in a spray-drier with an outlet temperature of 250° C. The intermediate product corresponding to the spray-drying step is recovered in a bag filter. This intermediate product is calcined at 600° C. for 4 hours. FIG. 21 shows a scanning electron micrograph of the product, enlarged 80,000 times. FIG. 22 shows the X-Ray diffraction pattern of the product and it shows that it consists of anhydrous lanthanum oxycarbonate. The X-Ray pattern is different from the pattern corresponding to Example 5, even though the chemical composition of the compound is the same. The formula for this compound is written as (La 2 CO 5 ). Comparing FIGS. 21 and 18 shows that the compound of the present example shows a structure of leaves and needles as opposed to the round particles formed in Example 5. The particles may be used in a device to directly remove phosphate from an aqueous or non-aqueous medium, e.g., the gut or the bloodstream. [0107] To determine the reactivity of the lanthanum compound with respect to phosphate, the following test was conducted. A stock solution containing 13.75 g/l of anhydrous Na 2 HPO 4 and 8.5 g/l of HCl was prepared. The stock solution was adjusted to pH 3 by the addition of concentrated HCl. An amount of 100 ml of the stock solution was placed in a beaker with a stirring bar. La 2 CO 5 powder, made as described above, was added to the solution. The amount of lanthanum oxycarbonate was such that the amount of La in suspension was 3 times the stoichiometric amount needed to react completely with the phosphate. Samples of the suspension were taken at intervals through a filter that separated all solids from the liquid. The liquid sample was analyzed for phosphorous. FIG. 23 shows the rate of phosphate removed from solution. EXAMPLE 8 (COMPARATIVE EXAMPLE) [0108] To determine the reactivity of a commercial lanthanum with respect to phosphate commercial lanthanum carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O was used instead of the lanthanum oxycarbonate made according to the present invention as described above. FIG. 23 shows the rate of phosphate removal for the commercial lanthanum carbonate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O. FIG. 23 also shows that the rate of phosphate removal with the lanthanum oxycarbonate is faster than the rate of phosphate removal with commercial lanthanum carbonate hydrate La 2 (CO 3 ) 3 .H 2 O and La 2 (CO 3 ) 3 .4H 2 O. EXAMPLE 9 [0109] To a solution of titanium chloride or oxychloride containing 120 g/l Ti and 450 g/l Cl is added the equivalent of 2.2 g/l of sodium phosphate Na 3 PO 4 . The solution is injected in a spray dryer with an outlet temperature of 250° C. The spray dryer product is calcined at 1050° C. for 4 h. The product is subjected to two washing steps in 2 molar HCl and to two washing steps in water. FIG. 24 is a scanning electron micrograph of the TiO 2 material obtained. It shows a porous structure with individual particles of about 250 nm connected in a structure. This structure shows good mechanical strength. This material can be used as an inert filtering material in a fluid stream such as blood. EXAMPLE 10 [0110] The product of Example 9 is re-slurried into a solution of lanthanum chloride containing 100 g/l La. The slurry contains approximately 30% TiO 2 by weight. The slurry is spray dried in a spray dryer with an outlet temperature of 250° C. The product of the spray drier is further calcined at 800° C. for 5 h. It consists of a porous TiO 2 structure with a coating of nano-sized lanthanum oxychloride. FIG. 25 is a scanning electron micrograph of this coated product. The electron micrograph shows that the TiO 2 particles are several microns in size. The LaOCl is present as a crystallized deposit with elongated crystals, often about 1 μm long and 0.1 μm across, firmly attached to the TiO 2 catalyst support surface as a film of nano-size thickness. The LaOCl growth is controlled by the TiO 2 catalyst support structure. Orientation of rutile crystals works as a template for LaOCl crystal growth. The particle size of the deposit can be varied from the nanometer to the micron range by varying the temperature of the second calcination step. [0111] FIG. 26 is a scanning electron micrograph corresponding to calcination at 600° C. instead of 800° C. It shows LaOCl particles that are smaller and less well attached to the TiO 2 substrate. FIG. 27 is a scanning electron micrograph corresponding to calcination at 900° C. instead of 800° C. The product is similar to the product made at 800° C., but the LaOCl deposit is present as somewhat larger crystals and more compact layer coating the TiO 2 support crystals. FIG. 28 shows the X-Ray diffraction patterns corresponding to calcinations at 600°, 800° and 900° C. The figure also shows the pattern corresponding to pure LaOCl. The peaks that do not appear in the pure LaOCl pattern correspond to rutile TiO 2 . As the temperature increases, the peaks tend to become higher and narrower, showing that the crystal size of the LaOCl as well as TiO 2 increases with the temperature. EXAMPLE 11 [0112] An aqueous HCl solution having a volume of 334.75 ml and containing LaCl 3 (lanthanum chloride) at a concentration of 29.2 wt % as La 2 O 3 was added to a 4 liter beaker and heated to 80° C. with stirring. The initial pH of the LaCl 3 solution was 2.2. Two hundred and sixty five ml of an aqueous solution containing 63.59 g of sodium carbonate (Na 2 CO 3 ) was metered into the heated beaker using a small pump at a steady flow rate for 2 hours. Using a Buchner filtering apparatus fitted with filter paper the filtrate was separated from the white powder product. The filter cake was mixed four times, each with 2 liters of distilled water and filtered to wash away the NaCl formed during the reaction. The washed filter cake was placed into a convection oven set at 105° C. for 2 hours or until a stable weight was observed. The X-Ray diffraction pattern of the product shows that it consists of hydrated lanthanum oxycarbonate La 2 O(CO 3 ) 2 .xH 2 O, where 2≦x≦4. The surface area of the product was determined by the BET method. The test was repeated 3 times and slightly different surface areas and different reaction rates were obtained as shown in Table 1. EXAMPLE 12 [0113] Six adult beagle dogs were dosed orally with capsules of lanthanum oxycarbonate La 2 O(CO 3 ) 2 .xH 2 O (compound A) or La 2 O 2 CO 3 (compound B) in a cross-over design using a dose of 2250 mg elemental lanthanum twice daily (6 hours apart). The doses were administered 30 minutes after provision of food to the animals. At least 14 days washout was allowed between the crossover arms. Plasma was obtained pre-dose and 1.5, 3, 6, 7.5, 9, 12, 24, 36, 48, 60, and 72 hours after dosing and analyzed for lanthanum using ICP-MS. Urine was collected by catheterization before and approximately 24 hours after dosing and creatinine and phosphorus concentrations measured. [0114] The tests led to reduction of urine phosphate excretion, a marker of phosphorous binding. Values of phosphate excretion in urine are shown in Table 2 below. TABLE 2 Median phosphorus/creatinine ratio (% reduction La Oxycarbonate compared to pre-dose compound value) 10 th and 90 th percentiles A 48.4% 22.6-84.4% B 37.0% −4.1-63.1% [0115] Plasma lanthanum exposure: Overall plasma lanthanum exposure in the dogs is summarized in Table 3 below. The plasma concentration curves are shown in FIG. 29 . TABLE 3 Mean (sd) Area Under the Maximum concentration La oxycarbonate Curve 0-72 h (ng · h/mL); C max (ng/mL); (standard compound tested (standard deviation) deviation) A 54.6 (28.0) 2.77 (2.1) B 42.7 (34.8) 2.45 (2.2) EXAMPLE 13 First In Vivo Study in Rats [0116] Groups of six adult Sprague-Dawley rats underwent ⅚th nephrectomy in two stages over a period of 2 weeks and were then allowed to recover for a further two weeks prior to being randomized for treatment. The groups received vehicle (0.5% w/v carboxymethyl cellulose), or lanthanum oxycarbonate A or B suspended in vehicle, once daily for 14 days by oral lavage (10 ml/kg/day). The dose delivered 314 mg elemental lanthanum/kg/day. Dosing was carried out immediately before the dark (feeding) cycle on each day. Urine samples (24 hours) were collected prior to surgery, prior to the commencement of treatment, and twice weekly during the treatment period. Volume and phosphorus concentration were measured. [0117] Feeding—During the acclimatization and surgery period, the animals were given Teklad phosphate sufficient diet (0.5% Ca, 0.3% P; Teklad No. TD85343), ad libitum. At the beginning of the treatment period, animals were pair fed based upon the average food consumption of the vehicle-treated animals the previous week. [0118] ⅚ Nephrectomy—After one week of acclimatization, all animals were subjected to ⅚ nephrectomy surgery. The surgery was performed in two stages. First, the two lower branches of the left renal artery were ligated. One week later, a right nephrectomy was performed. Prior to each surgery, animals were anesthetized with an intra-peritoneal injection of ketamine/xylazine mixture (Ketaject a 100 mg/ml and Xylaject at 20 mg/ml) administered at 10 ml/kg. After each surgery, 0.25 mg/kg Buprenorphine was administered for relief of post-surgical pain. After surgery, animals were allowed to stabilize for 2 weeks to beginning treatment. [0119] The results showing urine phosphorus excretion are given in FIG. 30 . The results show a decrease in phosphorus excretion, a marker of dietary phosphorus binding, after administration of the lanthanum oxycarbonate (at time>0), compared to untreated rats. EXAMPLE 14 Second In Vivo Study in Rats [0120] Six young adult male Sprague-Dawley rats were randomly assigned to each group. Test items were lanthanum oxycarbonates La 2 O 2 CO 3 and La 2 CO 5 (compound B and compound C), each tested at 0.3 and 0.6% of diet. There was an additional negative control group receiving Sigmacell cellulose in place of the test item. [0121] The test items were mixed thoroughly into Teklad 7012CM diet. All groups received equivalent amounts of dietary nutrients. [0122] Table 4 outlines the dietary composition of each group: TABLE 4 Sigmacell Group ID Treatment Test Item cellulose Teklad Diet I Negative 0.0% 1.2% 98.8% control II Compound B - 0.3% 0.9% 98.8% Mid level III Compound B - 0.6% 0.6% 98.8% High level IV Compound C - 0.3% 0.9% 98.8% Mid level V Compound C - 0.6% 0.6% 98.8% High level [0123] Rats were maintained in the animal facility for at least five days prior to use, housed individually in stainless steel hanging cages. On the first day of testing, they were placed individually in metabolic cages along with their test diet. Every 24 hours, their output of urine and feces was measured and collected and their general health visually assessed. The study continued for 4 days. Food consumption for each day of the study was recorded. Starting and ending animal weights were recorded. [0124] Plasma samples were collected via retro-orbital bleeding from the control (I) and high-dose oxycarbonate groups, III and V. The rats were then euthanized with CO 2 in accordance with the IACUC study protocol. [0125] Urine samples were assayed for phosphorus, calcium, and creatinine concentration in a Hitachi 912 analyzer using Roche reagents. Urinary excretion of phosphorus per day was calculated for each rat from daily urine volume and phosphorus concentration. No significant changes were seen in animal weight, urine volume or creatinine excretion between groups. Food consumption was good for all groups. [0126] Even though lanthanum dosage was relatively low compared to the amount of phosphate in the diet, phosphate excretion for 0.3 or 0.6% La added to the diet decreased as shown in Table 5 below. Table 5 shows average levels of urinary phosphate over days 2, 3, and 4 of the test. Urine phosphorus excretion is a marker of dietary phosphorous binding. TABLE 5 Urinary phosphate excretion (mg/day) Control 4.3 Compound B = La 2 O 2 CO 3 2.3 Compound C = La 2 CO 5 1.9 EXAMPLE 15 [0127] Tests were run to determine the binding efficiency of eight different compounds for twenty-four different elements. The compounds tested are given in Table 6. TABLE 6 Test ID Compound Preparation Technique 1 La 2 O 3 Calcined the commercial (Prochem) La 2 (CO 3 ) 3 .H 2 O at 850° C. for 16 hrs. 2 La 2 CO 5 Prepared by spray drying lanthanum acetate solution and calcining at 600° C. for 7 hrs (method corresponding to FIG. 3) 3 LaOCl Prepared by spray drying lanthanum chloride solution and calcining at 700° C. for 10 hrs (method corresponding to FIG. 1) 4 La 2 (CO 3 ) 3 .4H 2 O Purchased from Prochem (comparative example) 5 Ti carbonate Made by the method of FIG. 11 , where the LaCl 3 solution is replaced by a TiOCl 2 solution. 6 TiO 2 Made by the method corresponding to FIG. 2 , with addition of sodium chloride. 7 La 2 O(CO 3 ) 2 . x H 2 O Precipitation by adding sodium carbonate solution to lanthanum chloride solution at 80° C. (Method corresponding to FIG. 10 ) 8 La 2 O 2 CO 3 Precipitation by adding sodium carbonate solution to lanthanum chloride solution at 80° C. followed by calcination at 500° C. for 3 hrs. (Method of FIG. 11 ) [0128] The main objective of the tests was to investigate the efficiency at the compounds bind arsenic and selenium, in view of their use in removing those nts from drinking water. Twenty-one different anions were also included to explore r possibilities. The tests were performed as follows: [0129] The compounds given in Table 6 were added to water and a spike and vigorously shaken at room temperature for 18 hrs. The samples were filtered and ltrate analyzed for a suite of elements including Sb, As, Be, Cd, Ca, Cr, Co, Cu, Fe, g, Mn, Mo, Ni, Se, Tl, Ti, V, Zn, Al, Ba, B, Ag, and P. [0130] The spike solution was made as follows: 1. In a 500 ml volumetric cylinder add 400 ml of de-ionized water. 2. Add standard solutions of the elements given above to make solutions containing approximately 1 mg/l of each element. 3. Dilute to 500 mls with de-ionized water. [0134] The tests were conducted as follows: 1. Weigh 0.50 g of each compound into its own 50 ml centrifuge tube. 2. Add 30.0 ml of the spike solution to each. 3. Cap tightly and shake vigorously for 18 hrs. 4. Filter solution from each centrifuge tube through 0.2 μm syringe filter. Obtain ˜6 ml of filtrate. 5. Dilute filtrates 5:10 with 2% HNO 3 . Final Matrix is 1% HNO 3 . 6. Submit for analysis. [0141] The results of the tests are given in Table 7. TABLE 7 % of the Analyte Removed Sb As Be Cd Ca Cr Co Cu Fe Pb Mg Mn La 2 O 3 89 85 97 95 21 100  69 89 92 92 0 94 La 2 CO 5 96 93 100  83  0 100  52 97 100  99 0 99 LaOCl 86 76 89 46  0 100  28 88 100  99 0 28 La 2 (CO 3 ) 3 .4H 2 O 84 25 41 37 28 94 20  0 56 90 0 20 Ti(CO 3 ) 2 96 93 100  100  99 99 99 98 100  98 79 100  TiO 2 96 93  8  4  0  6  0 11 49 97 0  1 La 2 O(CO 3 ) 2 . x H 2 O 87 29 53 37 28 100  20 10 58 98 0 25 La 2 O 2 CO 3 97 92 100  85 21 100  59 98 100  99 0 99 Mo Ni Se Tl Ti V Zn Al Ba B Ag P La 2 O 3 89 28 72  8 90 95 95 85 23 0 47 96 La 2 CO 5 98 17 79  8 100  99 100  93  0 0 73 99 LaOCl 94  0 71 13 100  99 24 92  7 0 96 96 La 2 (CO 3 ) 3 .4H 2 O 98  1 78  5 100  99 16 11 23 0 48 71 Ti(CO 3 ) 2 91 98 97 96 24 100  100  92 100  0 99 98 TiO 2 97  0 97 62  0 86  0  0  0 30 99 66 La 2 O(CO 3 ) 2 . x H 2 O 99  0 79  8 100  99 16 60 26 0 44 74 La 2 O 2 CO 3 99 34 81 12 100  99 100  92 23 0 87 99 [0142] The most efficient compounds for removing both arsenic and selenium appear to be the titanium-based compounds 5 and 6. The lanthanum oxycarbonates made according to the process of the present invention remove at least 90% of the arsenic. Their efficiency at removing Se is in the range 70 to 80%. Commercial lanthanum carbonate (4 in Table 6) is less effective. [0143] The tests show that the lanthanum and titanium compounds made following the process of the present invention are also effective at removing Sb, Cr, Pb, Mo from solution. They also confirm the efficient removal of phosphorus discussed in the previous examples. [0144] While the invention has been described in conjunction with specific embodiments, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and scope of the appended claims.

Rare earth metal compounds, particularly lanthanum, cerium, and yttrium, are formed as porous particles and are effective in binding metals, metal ions, and phosphate. A method of making the particles and a method of using the particles is disclosed. The particles may be used in the gastrointestinal tract or the bloodstream to remove phosphate or to treat hyperphosphatemia in mammals. The particles may also be used to remove metals from fluids such as water.

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of pending U.S. application Ser. No. 12/944,017, filed on Nov. 11, 2010, the entirety of which is herein incorporated by reference, which is a divisional of U.S. application Ser. No. 11/032,285, filed on Jan. 10, 2005, now U.S. Pat. No. 7,854,022, issued Dec. 21, 2010. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to garments. More particularly, the present invention relates to garments having edge bands seamlessly secured thereto and processes for making such garments. [0004] 2. Description of Related Art [0005] Many types of garments require bands secured to the edge of the garment. In some instances, the bands provide elasticity to the edge of the garment to maintain the garment in a desired location when worn. For example, intimate apparel garments such as, but not limited to, briefs and panties include an elastic waistband and often include elastic leg bands. Garments such as brassieres include an elastic chest band, while garments such as socks and hosiery include elastic leg bands. In other instances, the bands may provide a decorative or aesthetic effect to the garment. [0006] Sewn seams have traditionally been used to secure bands to the garment edges; however, in applications where a band rests against the skin of the wearer, the sewn seams may be a source of physical and/or aesthetic discomfort. For example, the seams may cause chaffing and discomfort to the skin, and may be bulky so as to be seen through the outer clothing of the wearer. [0007] Adhesives have been previously used to secure bands to garments. While adhered bands can resolve some of the discomforts associated with sewn seams, the adhered bands can lead to other deleterious effects. For example, the normal washing and drying cycles that typical garments are exposed to require the use of aggressive adhesives that may diminish the elasticity of the band and/or negatively effect the hand feel of the garment. Also, the manufacture of garments having adhered bands has proven to require additional process steps that lead to increased garment costs and decreased productivity. [0008] The use of sonic energy, both subsonic and ultrasonic, to bond or weld (hereinafter “weld”) materials having thermoplastic components has also been used to secure elastic bands to garments, such as in the disposable diaper industry. The process typically involves the use of high frequency mechanical vibrations that cause friction and melting at adjoining surfaces of the thermoplastic components, fusing them together in a strong molecular bond. Typically, the process includes pressing the materials to be joined between a vibrating horn and an anvil. The horn channels mechanical vibrations into the materials to fuse the materials at the location of the horn. While sonically welded elastic bands can result in increased productivity, they have not proven durable enough for many non-disposable garment applications. [0009] Accordingly, there is a continuing need for garments having bands seamlessly secured thereto and processes for making such garments that resolve one or more deleterious effects and drawbacks of prior garments and processes. BRIEF SUMMARY OF THE INVENTION [0010] It is an object of the present invention to provide garments having bands seamlessly secured thereto. [0011] It is another object to provide processes for seamlessly securing bands to garments. [0012] These and other objects and advantages of the present invention are provided by a garment having a fabric layer and an edge band. The edge band and the fabric layer each include a sonically weldable material. In one embodiment, the garment comprises a sonic edge weld securing the edge band to the fabric layer along a cut edge of the garment, and an adhesive securing the edge band to the fabric layer. [0013] Further objects and advantages are provided by a process for making a garment. One process includes: (1) placing an edge band on a fabric layer, the fabric layer and edge band each including a sonically weldable material, (2) applying sonic energy to the fabric layer and the edge band so that the fabric layer and the edge band are simultaneously trimmed along a cut edge and welded to one another along the cut edge, and (3) activating an adhesive between the fabric layer and the edge band to adhere the edge band to the fabric layer. [0014] The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is a perspective view of an exemplary embodiment of a garment according to the present invention; [0016] FIG. 2 is a view of the garment of FIG. 1 prior to the addition of side seams; [0017] FIG. 3 is a sectional view taken along lines 3 - 3 of FIG. 2 ; [0018] FIG. 4 is a view of a portion of an alternate exemplary embodiment of the garment of FIG. 1 ; [0019] FIG. 5 is a sectional view taken along lines 5 - 5 of FIG. 4 ; and [0020] FIGS. 6 through 10 schematically depict an exemplary embodiment of a manufacturing process according to the present invention for the garment of FIG. 1 . DETAILED DESCRIPTION OF THE INVENTION [0021] Referring to the drawings and in particular to FIGS. 1 and 2 , an exemplary embodiment of a garment according to the present invention, generally referred to by reference numeral 10 is shown. Garment 10 includes a fabric layer 12 having an edge band 14 secured to one or more regions of the fabric layer. In the illustrated embodiment, garment 10 includes side seams 16 for securing portions of fabric layer 12 to one another. [0022] Garment 10 is illustrated by way of example as a panty having an elastic edge band 14 secured to a waist region 18 and leg region 20 . Of course, it is contemplated by the present invention for garment 10 to be any other apparel or clothing item such as, but not limited to, a brassiere, a shirt, a pair of pants, a coat, a sock, a pair of pantyhose, a bathing suit, a camisole, a boxer short, a men's brief, and any other clothing item having an edge band secured to any desired region. [0023] In addition, garment 10 is illustrated by way of example having a single fabric layer 12 . Of course, it is contemplated by the present invention for the garment to include more than one fabric layer 12 . [0024] Edge band 14 is seamlessly secured to fabric layer 12 by an edge weld 22 and an adhesive 24 . As described in detail below, the energy input into garment 10 to define edge weld 22 may also simultaneously trim fabric layer 12 and edge band 14 to define a cut edge 26 of garment 10 . Advantageously, edge weld 22 also seals cut edge 26 so that the free outer edge of fabric layer 12 and a free edge of the edge band 14 terminate at the same point and do not fray during use of garment 10 . Further, the simultaneous cutting of fabric layer 12 and edge band 14 at cut edge 26 ensures that the fabric layer and band are co-planar at the cut edge. Thus, fabric layer 12 and edge band 14 are sonically welded to one another along cut edge 26 and are adhered to one another in the remaining portions where the band overlaps the fabric layer. In one embodiment, the adhesive 24 is applied along more than half of the inner surface of the edge band 14 . [0025] In some embodiments, edge band 14 may further be seamlessly secured to fabric layer 12 by one or more tack welds 28 . As described in detail below, edge weld 22 , and tack welds 28 if present, hold fabric layer 12 and edge band 14 in place with respect to one another during the manufacturing process prior to activation of adhesive 24 . [0026] Fabric layer 12 and/or edge band 14 may be formed of any non-woven fabric, woven fabric, or knitted fabric having between about ten percent and about one hundred percent of a sonically weldable material and all subranges therebetween. Sonically weldable materials include polypropylene, lycra spandex, tricot, polyester, nylon, acrylic, vinyl, PVC, thermoplastic urethane, or any combinations and blends thereof. Advantageously, fabric layer 12 and/or edge band 14 have up to about ninety percent natural fibers. [0027] In one embodiment, fabric layer 12 and/or edge band 14 may be a blend of about sixty percent sonically weldable material and about forty-percent natural fibers. In another embodiment, fabric layer 12 is a blend of about twelve percent sonically weldable material and about eighty-eight percent natural fibers, while edge band 14 is a one hundred percent sonically weldable material. It is believed that fabric layer 12 and/or edge band 14 may include at least about 70 percent natural fibers. [0028] The adhesive 24 may be any heat activated adhesive material. In some embodiments, adhesive 24 may impart a desired elasticity to garment 10 . In other embodiments, edge band 14 alone, or in combination with adhesive 24 , may impart a desired elasticity to garment 10 . Thus, garment 10 may be provided with elasticity at its edges by adhesive 24 , edge band 14 , or any combination thereof. [0029] Adhesive 24 is preferably a heat activated adhesive net or film. For example, adhesive 24 may be a heat activated adhesive net that provides elasticity to garment 10 such as the adhesive nets commercially available under the DELNET® tradename from Delstar Technologies of Austin, Tex. In another example, adhesive 24 may be a heat activated elastic film such as the adhesive films commercially available under the tradename SEWFREE® from Bemis Associates Incorporated of Shirley, Mass. [0030] Referring now to FIGS. 4 and 5 , an alternate exemplary embodiment of garment 10 is shown. Here, fabric layer 12 and edge band 14 are shown having various decorative features incorporated therein. For example, cut edge 26 is provided with a decorative pattern 30 such as, but not limited to, a scallop edge. Again, edge weld 22 is defined at decorative pattern 30 to seal cut edge 26 . [0031] In addition, fabric layer 12 and edge band 14 may include multiple cut edges 26 to provide garment 10 with a decorative effect 32 , such as a lace effect. Here, an edge weld 22 is defined at each of the cut edges 26 of decorative effect 32 . [0032] In some embodiments, edge band 14 may further be seamlessly secured to fabric layer 12 by one or more tack welds 28 . However, it has also been found that provision of multiple cut edges 26 and, thus, multiple edge welds 22 , not only provides decorative effect 32 , but also can mitigate the need for additional tack welds 28 . [0033] An exemplary embodiment of a process 40 for making garment 10 is described with reference to FIGS. 6 though 10 . During a first step of process 40 shown in FIG. 6 , fabric layer 12 is trimmed to the approximate shape of the finished garment. For example, fabric layer 12 may be trimmed to define a selvage 42 outside a final garment shape 44 (illustrated in phantom). [0034] During a second step of process 40 , shown in FIG. 7 , edge band 14 is secured to fabric layer 12 along a portion of waist region 18 . During the second process step, adhesive 24 and edge band 14 are placed on fabric layer 12 to cover a portion of selvage 42 and a portion of final garment shape 44 . [0035] In a preferred embodiment, adhesive 24 is laminated on edge band 14 prior to placement of the edge band on fabric layer 12 . Here, edge band 14 is placed on fabric layer 12 so that adhesive 24 is in contact with the fabric layer. [0036] As edge band 14 and adhesive 24 are placed on fabric layer 12 , the edge band, adhesive, and fabric layer are sonically cut and welded along final shape 44 to define edge weld 22 (not shown) and cut edge 26 . Selvage 42 having both fabric layer 12 and edge band 14 is removed and discarded. In some embodiments, fabric layer 12 and edge band 14 are also sonically welded to define tack welds 28 (not shown). Accordingly, the second process step applies sonic energy with sufficient intensity to simultaneously cut fabric layer 12 , adhesive 24 , and edge band 14 along cut edge 26 and weld the fabric layer and edge band to one another at edge weld 22 and, if present, at tack welds 28 . For example, it is contemplated for process 40 to expose fabric layer 12 and edge band 14 to sonic energy of between about 20 and 60 kilohertz (kHz) and a pressure of between about 20 and 40 pounds per square inch (psi). [0037] In a preferred embodiment, the second process step of process 40 is carried out using a sealing and bonding machine commercially available under the tradenames SEAMMASTER or LACEMASTER from Sonobond Ultrasonics of West Chester, Pa. [0038] At this point, fabric layer 12 and edge band 14 are held in place with respect to one another by edge weld 22 and, if present, by tack welds 28 . The sonic energy that creates cut edge 26 and welds 22 , 28 also locally activates adhesive 24 . Thus, welds 22 , 28 include components of fabric layer 12 , edge band 14 , and adhesive 24 in addition to a localized area of activated adhesive surrounding around the welds. However, adhesive 24 remains un-activated in the remaining portions of overlap between fabric layer 12 and edge band 14 . [0039] During a third step of process 40 , shown in FIG. 8 , the second process step is repeated to secure edge band 14 to the remaining waist and leg regions 18 , 20 , as desired. Again, fabric layer 12 and edge band 14 are held in place with respect to one another by the sonic welds, but adhesive 24 remains largely un-activated. [0040] Process 40 can be easily modified to provide tack welds 28 , decorative pattern 30 , and/or decorative effect 32 as desired. For example, the horn used to apply sonic energy during the second and third steps may be modified using known methods to provide the tack welds 28 , decorative pattern 30 and/or decorative effect 32 , as desired. [0041] During a fourth step of process 40 , shown in FIG. 9 , adhesive 24 is activated. For example, fabric layer 12 and edge band 14 may be compressed between a pair of presses 46 at a pressure, temperature, and/or time sufficient to activate adhesive 24 . At the end of the fourth step, fabric layer 12 and edge band 14 are secured to one another by edge weld 22 , adhesive 24 , and tack welds 28 , if any. [0042] Finally, garment 10 may be completed by folding the garment and adding side seams 16 for securing portions of fabric layer 12 to one another, as shown in FIG. 10 . [0043] Advantageously, process 40 uses sonic welds 22 , 28 to hold fabric layer 12 and edge band 14 in place with respect to one another while cutting through both the edge band and fabric, so that the edges are co-planar with one another. Process 40 then activates adhesive 24 to firmly secure edge band 14 to fabric layer 12 without deleteriously effecting the elastic characteristics of the edge band or the hand feel of the edge band and fabric. It has been determined that the combination of edge weld 22 and adhesive 24 , as well as tack welds 28 if present, provide garment 10 with a desired durability, washability, hand feel, and method of manufacture not previously possible. [0044] It should also be noted that the terms “first”, “second”, “third”, “upper”, “lower”, and the like may be used herein to modify various elements. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated. [0045] While the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment(s) disclosed, but that the disclosure will include all embodiments falling within the scope of the appended claims.

A method is provided for forming a garment, including providing a fabric layer having sonically weldable material, the fabric layer having an inner surface and at least one opening region, the opening region having a periphery and an outer free edge, placing an elastic edge band having sonically weldable material around the entire periphery of the opening region, the edge band having first and second free edges and an inner surface, securing the first free edge of the edge band to the outer free edge of the opening region with a subsonic or ultrasonic edge weld to form a finished seamless edge along the opening region, and activating an adhesive along more than half of the inner surface of the edge band to secure the edge band and second free edge to the inner surface of the fabric layer.

FIELD OF THE INVENTION This invention relates to automatic gain control in photodetectors, such as those used in a variety of electro-optical applications. BACKGROUND AND SUMMARY OF THE INVENTION Circuits that employ an automatic gain control for controlling the gain of a photomultiplier tube (PMT) or similar photodetector are known in the prior art. For example, the prior art circuit shown in FIG. 1 employs an operational amplifier (op-amp) 10 in a integrating configuration, where resistor R and capacitor C set the integration time constant as the product R*C seconds. The filtered DC portion of the PMT output signal 12 (hereafter referred to as “PMT output”) is compared to a pre-selected DC reference 14 . The output of the op-amp 10 is applied to the bias control 16 of the PMT, thereby to drive the PMT at a level such that the PMT output matches the DC reference. For example, if the level of the PMT output reaching the op-amp 10 is below the DC reference 14 , the op-amp will provide to the PMT bias control 16 a signal for driving the PMT at a relatively higher level until the PMT output matches the DC reference. A controller (not shown) monitors and conditions the signals directed to and from the op-amp 10 . For example, in instances where the DC reference is user-selected, the system provides a user interface for receiving the selected input from the user, which input the controller converts as necessary to a corresponding DC reference level applied to the op-amp 10 . It is important that, despite the selected DC reference, the PMT gain be limited to an amount that does not cause the applied bias voltage to overdrive, hence damage, the PMT. Moreover, such techniques for limiting the PMT gain should not interfere with the precision with which the PMT output may be established (by selection of the DC reference) below that limited level. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 a diagram of a prior art automatic gain control circuit for a photomultiplier tube (PMT). FIG. 2 is a diagram of a preferred embodiment of an automatic gain control for a PMT, including a mechanism for limiting the gain to a level less than that which would otherwise lead to overdriving, hence damaging, the PMT. FIG. 3 is a flow diagram for illustrating an aspect of the invention that ensures precise selection of the DC reference voltage level. DETAILED DESCRIPTION FIG. 2 is a diagram of a preferred embodiment of an automatic gain control for a PMT, including a mechanism for limiting the gain to a level less than that which would otherwise lead to overdriving, hence damaging, the PMT. The circuit of FIG. 2 includes an operational amplifier (op-amp) 20 in an integrating configuration. The filtered DC portion of the PMT output signal 22 (hereafter referred to as “PMT output”) is applied to the negative input of the op-amp 20 . The selected DC reference voltage 24 is applied to the positive input of the op-amp 20 . In this preferred configuration, however, a Zener diode 26 is interconnected between the op-amp 20 and DC reference 24 , as shown in FIG. 2 , with its anode terminal grounded. The Zener diode breakdown or Zener voltage is selected to establish the upper limit of voltage (here, the upper limit of the DC reference) that can be applied to the op-amp 20 , hence limiting the bias voltage that can be applied to the PMT via the PMT bias control 30 . In one embodiment the Zener voltage is 1.8 volts. Thus, if the DC reference 24 is selected to be above that amount, the Zener diode becomes conductive and shunts the DC reference voltage to ground, thereby preventing the undesirably high voltage from appearing at the positive input of the op-amp 20 . A resistor 28 (preferably 61.9 k Ohms in this embodiment) is located between the DC reference and the Zener diode 26 for protecting that diode from current levels that may damage the Zener diode itself. In the preferred embodiment, the Zener voltage is relatively low. One can observe that, for such a low-voltage limit, the Zener diode will become conductive at voltage levels below the limit. Put another way, the Zener diode may become “leaky” at voltage levels approaching the established Zener voltage and thus prevent the application of the correct, selected DC reference voltage from reaching the op-amp, even though the selected DC reference voltage is less than the (Zener voltage) upper limit. The consequent lack of precision in applying the particularly selected DC reference voltage to the op-amp 20 for creating the sought-after gain of the PMT is unacceptable in many applications. Accordingly, as another aspect of the present invention, there is provided a technique that compensates for the voltage drop attributable to a “leaky” Zener diode effect explained above. To this end, voltage measurements are taken at the positive input of the op-amp and correlated to the selected DC reference voltage level. Numerous such measurements are taken at suitable increments of selected DC reference levels. The correlated data is stored as a look-up table for use by the controller for compensating for losses caused by the leaky Zener diode. This is explained in more detail next, with reference to the flow diagram of FIG. 3 . An implementation of the present invention may provide a user interface 32 whereby the user may select the desired PMT gain represented by the DC reference 36 . It is noteworthy here that although a user-selected DC reference signal is discussed for this embodiment, it is also contemplated that other means for establishing the desired DC reference may be used, including automated methods based, for example, on changes in environmental conditions of the photodetectors of interest. In either case, the protection of the photodetectors and compensation for leaky Zener diodes is desired. Once the user selects a DC reference value, the look-up table is consulted 34 to find the correlating voltage that is actually applied to the op-amp 20 as a result of the leaky Zener diode effect mentioned above. In instances where the actual and selected levels are unequal, the controller adjusts the DC reference 34 by the difference indicated in the look-up table so that the level applied to the op-amp 20 will match what the user selected for the desired gain of the PMT. As noted, it is contemplated that the present invention is useful for automatic gain control of other types of photodetectors, such as avalanche photo-diodes. Also, other mechanisms for limiting the voltage applied to the op-amp may be used. For example, a resistor could be used in lieu of the Zener diode, with a corresponding look-up table developed and stored for use as discussed above.

The amount of gain applied to a photodetector such as a photomultiplier tube (PMT) is limited to an amount that does not cause the applied PMT bias voltage to overdrive, hence damage, the PMT. Techniques for limiting the PMT gain are implemented in a way that does not interfere with the precision with which the PMT gain may be established (by selection of a reference level) below that limited level.

FIELD OF THE INVENTION The invention is directed toward methodologies and apparatus for use in the preparation of devitalized, i.e. essentially lacking in reproductively viable cells and/or metabolically viable cells, while preferably retaining reproductively non-viable cells and/or metabolically non-viable cells and/or large molecular weight cytoplasmic proteins including actin, soft-tissue implants, in small quantities and commercializable quantities. Such soft-tissue implants include vascular graft substitutes. These implants can be derived from tissue engineered soft tissue devices, tissue products derived from animal or human donors that contain cells, and that contain or are devoid of valve structures useful in directing the flow of fluids through tubular vascular devices, and/or combinations of natural tissue products and tissue engineered soft-tissue products. The invention includes methodologies and apparatus for producing uniform, gently processed, devitalized multiple soft tissue implants, where processing time is significantly reduced and the number of implants produced per day is increased. The devitalized grafts produced are significantly improved in long-term durability and function when used in clinical applications. BACKGROUND OF THE INVENTION Numerous types of vascular graft substitutes have been produced in the last four decades. These vascular graft substitutes have included large and small diameter vascular, blood carrying tubular structures, grafts containing valvular structures (vein substitutes, and heart valve substitutes) and lacking valvular structures (artery substitutes). The materials out of which these vascular grafts have been constructed have included man-made polymers, notably Dacron and Teflon in both knitted and woven configurations, and non-man-made polymers, notably tissue engineered blood vessels such as described in U.S. Pat. Nos: 4,539,716, 4,546,500; 4,835,102; and blood vessels derived from animal or human donors such as described in U.S. Pat. Nos. 4,776,853; 5,558,875; 5,855,617; 5,843,181; and 5,843,180. The prior art processing methods are directed to decellularizing tissue grafts, i.e. removing all cellular elements leaving a tissue matrix free from cellular elements, and are prohibitively time consuming, easily requiring numerous days, for example anywhere from eight to twenty-one days total processing time. Such long processing times result in proteolytic degradation of the matrix structures of the processed tissues. Over the past few decades numerous efforts have been made to manage the large surgical use of vascular prostheses in the treatment of vascular dysfunctions/pathologies. While vascular prostheses are available for clinical use, they have met with limited success due to cellular and immunological complications, and the inability to remain patent and function. These problems are especially pronounced for small diameter prostheses, i.e. less than about 6 mm. Efforts have been directed at removing those aspects of allograft and xenograft vascular prostheses that contribute to immunological “rejection” and these efforts have focused primarily on development of various “decellularization” processes, which processes require unduly burdensome incubation times. In addition the prior art methods involve using volumes of processing solutions which do not lend themselves to the production of large numbers of vascular grafts, which ability to “scale-up” is necessary for economic clinical use. The inventive process produces devitalized grafts including but not limited to ligaments, tendons, menisci, cartilage, skin, pericardium, dura mater, fascia, small and large intestine, placenta, veins, arteries, and heart valves. The process is advantageous over prior art processes in that processing times and conditions have been optimized and reduced, and the economics of production have been dramatically improved, resulting in large numbers of uniform, non-immunogenic grafts being produced. The grafts produced are non-immunogenic, are substantially free from damage to the matrix, and are substantially free from contamination including for example free from infectious agents. The invention involves the use of one or more non-denaturing agent, for example N-lauroylsarcosinate, for the treatment of tissues with the dual objective of devitalization and treatment of tissues to enhance recellularization upon implantation. The invention is directed at a process for producing devitalized soft-tissue implants including vascular grafts, veins, arteries, and heart valves, where processing times and conditions have been optimized to dramatically improve on the economics of production as well as to produce a graft with minimum damage to the matrix structure of the devitalized graft. SUMMARY OF THE INVENTION The inventive process is a process for preparing biological material(s) for implantation into a mammalian cardiovascular system, musculoskeletal system, or soft tissue system. The process removes reproductively viable cells and/or metabolically viable cells, while preferably retaining reproductively non-viable cells and/or metabolically non-viable cells and/or large molecular weight cytoplasmic proteins including for example, actin. The process provides for the production of commercializable quantities of devitalized soft tissue grafts for implantation into mammalian systems by removing reproductively viable cells and/or metabolically viable cells, while preferably retaining reproductively non-viable cells and/or metabolically non-viable cells and/or large molecular weight cytoplasmic proteins, such proteins including actin, forming an devitalized non-soluble matrix, the matrix having as major components collagens, elastins, hyaluronins, and proteoglycans. The devitalized tissue produced can be implanted into a mammalian system and recellularized in vitro, or recellularized in vitro and subsequently implanted into a mammalian system. An embodiment of the process includes the following steps: isolating from a suitable donor a desired tissue sample of the biological material; extracting the tissue with mildly alkaline hypotonic buffered solution of an endonuclease such as Benzonase® (a registered product of Merck KGaA, Darmstadt, Germany) and one or more non-denaturing detergents, preferably one or more anionic non-denaturing detergents; optionally treating the tissue with a hypotonic buffered salt solution; optionally treating the tissue with a hypertonic buffered salt solution; washing the tissue with water, preferably ultrapure water followed by a water solution optionally containing one or more decontaminating agents including for example chlorine dioxide; and storage in a sealed container in a storage solution optionally including isotonic saline, and/or one or more decontaminating agents. The invention provides a process for preparing an devitalized soft tissue graft for implantation into a mammalian system and/or commercializable quantities of devitalized soft tissue grafts, including extracting a soft tissue sample with an extracting solution including one or more non-denaturing detergents, for example one or more non-denaturing anionic detergents, and one or more endonucleases, to produce extracted tissue; optionally treating the tissue with a hypertonic buffered salt solution to produce a treated tissue; washing the treated tissue with water followed by treating with a water solution of a decontaminating solution including one or more decontaminating agents to produce the devitalized soft tissue graft; and storing the devitalized soft tissue graft in a storage solution optionally comprising one or more decontaminating agents. The invention provides a process for devitalizing soft tissue grafts without altering the matrix structure of the graft and without inhibiting subsequent recellularization of the soft tissue graft either in vitro, ex vivo, or in vivo. The invention also provides a process for preparing an devitalized soft tissue graft for implantation into a mammalian system, including inducing a pressure mediated flow of an extracting solution including one or more non-denaturing detergents and one or more endonucleases, through soft tissue, to produce extracted tissue; inducing a pressure mediated flow of a decontaminating solution including one or more decontaminating agents through the treated tissue, to produce the devitalized soft tissue graft; and storing the devitalized soft tissue graft in a storage solution including one or more decontaminating agents. The invention provides a process where the extracting solution is recirculated through the soft tissue graft. The invention further provides a process where the treating solution is recirculated through the soft tissue graft. The invention also provides a process where the decontaminating solution is recirculated through the soft tissue graft. The invention provides a process for preparing an devitalized soft tissue graft for implantation into a mammalian system, including extracting a soft tissue sample with an extracting solution comprising one or more non-denaturing detergents and one or more endonucleases, to produce extracted tissue; washing said extracted tissue with a decontaminating solution comprising one or more decontaminating agents to produce said devitalized soft tissue graft; and storing said devitalized soft tissue graft in a storage solution wherein a devitalized soft tissue graft retaining large molecular weight proteins is produced. The invention also provides a devitalization process does not employ a denaturing detergent. The invention further provides a devitalization process which includes prior to said step of washing, first washing said extracted tissue with water. The invention provides a process for preparing an devitalized soft tissue graft for implantation into a mammalian system, including first inducing a pressure mediated flow of an extracting solution including one or more non-denaturing detergents and one or more endonucleases, through soft tissue, to produce extracted tissue; inducing a pressure mediated flow of decontaminating solution optionally including one or more decontaminating agents, through said treated tissue; to produce said devitalized soft tissue graft; and storing said devitalized soft tissue graft in a storage solution. The invention also provides a devitalization process where prior to the step of inducing, inducing a pressure mediated flow of a washing solution through said extracted tissue. The invention also provides a devitalization process where extracting solution, and/or the decontaminating solution, and/or the washing solution, is recirculated through said soft tissue graft. The invention provides a devitalization process where the non-denaturing detergent includes one or more detergents selected from the group consisting of: N-lauroylsarcosinate, a polyoxyethylene alcohol, a polyoxyethylene isoalcohol, a polyoxyethylene p-t-octyl phenol, a polyoxyethylene nonyphenol, a polyoxyethylene ester of a fatty acid, and a polyoxyethylene sorbitol ester. The invention also provides a devitalization process where the decontaminating solution comprises ultrapure, endotoxin-free, water and/or water solutions of one or more decontaminating agents, where the decontaminating agents are non-reactive towards the one or more non-denaturing detergents. The invention provides a devitalized tissue graft, including a soft tissue sample substantially free from reproductively viable and/or metabolically viable and/or cellular elements produced by the inventive process where recellularization of the devitalized tissue graft in vivo or in vitro, is enhanced. The invention further provides a devitalized tissue graft, including a soft tissue sample substantially free from reproductively viable and/or metabolically viable and/or cellular elements. The invention also provides a devitalized soft tissue sample which is a heart valve, and where the devitalized heart valve leaflets maintain normal coaptation. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a view of one embodiment of the processing chamber showing flow mediated processing of long vein segments. FIG. 2 illustrates a view of an embodiment of the processing chamber showing flow mediated processing of a heart valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Definitions. The below definitions serve to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms. Non-denaturing Detergent. By the term “non-denaturing detergent” is intended any detergent that does not denature protein and includes for example, one or more detergents selected from the group consisting of: N-lauroylsarcosinate, a polyoxyethylene alcohol, a polyoxyethylene isoalcohol, a polyoxyethylene p-t-octyl phenol, a polyoxyethylene nonyphenol, a polyoxyethylene ester of a fatty acid, and a polyoxyethylene sorbitol ester. Decontaminating. Agent By the term “decontaminating agent” is intended one or more agents which remove or inactivate/destroy any infectious material potentially present in a biological tissue sample, for example, such agents include but are not limited to one or more of the following: an antibacterial agent; an antiviral agent; an antimycotic agent; an alcohol for example, methyl, ethyl, propyl, isopropyl, butyl, and/or t-butyl; trisodium phosphate; a preservative such as chlorine dioxide, isopropanol, METHYLPARABIN (Croda, Inc.), antimicrobials, antifungal agents, sodium hydroxide; hydrogen peroxide; a detergent, and ultrapure water, where the decontaminating agent or agents do not biologically alter the matrix components of the soft tissue grafts. Essentially Free From. By the term “Essentially Free From” is intended for the purposes of the present invention, a soft tissue graft where the material removed (for example, cellular elements and infectious materials) from the soft tissue graft is not detectable using detection means known in the art at the time of filing of this application. Normal Tissue. By the term “normal tissue” is intended for the purposes of the present invention, a particular soft tissue, for example a vein, artery, heart valve, ligament, tendon, fascia, dura mater, pericardium or skin, present in a living animal, including for example a human, a pig, and/or a cow. Tensile properties, as well as other mechanical properties, of a particular devitalized soft tissue graft approximate, that is, are not statistically significantly different from, the tensile properties of that tissue in a living animal. Devitalized Soft Tissue Graft. Bye the term “devitalized tissue graft” is intended for the purposes of the present invention, soft tissue including but not limited to veins, arteries, heart valves, ligaments, tendons, fascia, dura matter, pericardium, and skin, from any mammalian source, including but not limited to, a human source, porcine source, and a bovine source, where the devitalized graft produced is allogenic or xenogenic to the mammalian recipient, and where the devitalized tissue is essentially free from reproductively and/or metabolically viable cells, for example, a graft devoid of reproductively viable cells could contain metabolically viable cells that are incapable of increasing the numbers of metabolically viable cells through the normal process of meiosis or mitosis; a graft devoid of metabolically viable cells would, for example, be a graft devoid of cells capable of engaging in those metabolic activities essential to the normal function of those cells, i.e. the cells would be metabolically dead, a metabolically dead cell might still be visible in histology sections appearing similar to a metabolically live cell when viewed with the use of a microscope; cellular remnants, including nucleic acids, small molecular weight proteins, lipids, and polysaccharides, while the devitalized tissue retains reproductively non-viable cells and/or metabolically non-viable cells and/or large molecular weight cytoplasmic proteins, such proteins including for example, actin. Non-viable Cells: By the term “non-viable cells” is intended cells that are metabolically and/or reproductively non-viable. A metabolically non-viable cell is a cell incapable of engaging in those metabolic activities essential to the normal function of that particular cell, i.e. the cells would be metabolically dead, a metabolically dead cell might still be visible in histology sections. A reproductively non-viable cell is a cell that is incapable of increasing its numbers. Cellular elements: By the term “cellular elements” is intended those components including but not limited to nucleic acids, small molecular weight proteins, lipids, polysaccharides, and large molecular weight cytoplasmic proteins. Large Molecular Weight Cytoplasmic Proteins: By the term “large molecular weight cytoplasmic proteins” is intended, cellular elements that are proteins having a high molecular weight that are present in the cytoplasm of cells, such proteins preferably including those having a molecular weight of from about 20 Kdaltons to about 2-4 million Kdaltons, and include for example actin, myosin, and/or neurofilaments. Salt Solution: By the term “salt solution” is intended water solutions of one or more salts. Suitable salts include but are not limited to: sodium hydroxide, sodium phosphate, potassium sulfate, lithium sulfate, calcium phosphate, potassium phosphate, lithium phosphate, ammonium chloride, magnesium chloride, calcium sulfate, calcium chloride, calcium hydroxide, magnesium chloride, lithium chloride, potassium chloride, and sodium chloride. Storage Solution: By the term “storage solution” is intended a solution for storing the devitalized tissue graft and includes for example isotonic saline and/or a decontaminating solution optionally including one or more decontaminating agents. Such solutions include for example, solutions of chlorine dioxide; alcohol solutions; isotonic solution containing one or more decontaminating agents, the decontaminating agents including for example low concentrations of chlorine dioxide or peracetic acid, 70% alcohol (preferably, for example ethanol or isopropanol), Paragon or Mackstat DM (DMDM Hydantoin & methylparaben, CAS no. mixture HMIS code 210, DMDM Hydantoin CAS no. 6440-58-0, HMIS code 300, respectively; McIntyre Group; Ltd, University Park, Ill., USA), ioding formulations, and/or isotonic saline. The invention provides a process for removing viable cells, cellular remnants, nucleic acids, small molecular weight proteins, lipids, and polysaccharides, while retaining metabolically non-viable and/or reproductively non-viable cells and/or retaining large molecular weight cytoplasmic proteins including for example, actin, and without resultant damage to the matrix and/or tissue structure. Preferably, the tissue thickness does not exceed about 8 mm, more preferably does not exceed about 6 mm, and most preferably does not exceed about 4 mm, such that the time intervals described herein are sufficient for the process solutions to penetrate the tissue. Processing times can be altered to accommodate thicker tissues. A quantity of endonuclease is used for a given volume of tissue, such that the quantity is sufficient to digest the DNA within that volume of tissue. The invention recognizes that the mechanical strength of soft tissue graft biomaterials resides in the matrix structure of the graft. The matrix structure of these biomaterials include collagens, elastins, mucopolysaccharides and proteoglycan components. The devitalization process does not compromise the mechanical strength of the graft necessary for in situ function. Although the description of the invention is directed primarily at processing vascular graft materials, it should be appreciated that this invention is not restricted to processing of vascular graft materials and can also be directed to processing non-vascular soft tissue grafts. Such tissue grafts include, but are not limited to, tissues such as tendons, fascia, ligaments, pericardium, intestine, skin, dura, and cartilage. Such soft tissue can be processed by one of ordinary skill in the art to which the present invention pertains by simple manipulation of the inventive processing times, without undue experimentation. Tissue is processed according to the invention by surgically removing normal healthy tissues (for example, veins, arteries, heart valves) from animals or humans. The removed tissue is then transported to a processing facility where the tissue is cleaned of extraneous matter and quickly submersed in the first processing (extracting) solution which includes hypotonic buffered solutions containing one or more endonucleases, for example Benzonase®, and one or more non-denaturing detergents including for example, N-lauroylsarcosinate. Other suitable non-denaturing detergents include N-lauroylsarcosinate, a polyoxyethylene alcohol, a polyoxyethylene isoalcohol, a polyoxyethylene p-t-octyl phenol, a polyoxyethylene nonyphenol, a polyoxyethylene ester of a fatty acid, and a polyoxyethylene sorbitol ester. Procurement and transport of tissue is preferably carried out sterilely and is held in a sterile container on wet ice in a solution iso-osmolar to the cellular population of the tissue being procured and transported. Furthermore, antibiotics may be added to the procurement and transport solution. The invention includes the use of one or more decontaminating agents including for example one or more antibiotics, anti-fungal agents or anti-mycotic agents. Other such agents can be added during processing if so desired to maintain sterility of the procured tissues. According to an aspect of the invention, a process for preparing biological material for implantation into a mammalian cardiovascular system, musculoskeletal system, or soft tissue system, or for recellularization in vitro, is provided and includes removing cells, cellular remnants, nucleic acids, small molecular weight proteins, lipids, and polysaccharides, while retaining large molecular weight cytoplasmic components, and forms an extrcellular matrix including collagens, elastins, proteoglycans, mucopolysaccharides, and large molecular weight cytoplasmic proteins, the process includes, isolating from a suitable donor a desired tissue sample of the biological material, extracting the tissue with mildly alkaline hypotonic buffered solution of one or more endonucleases, for example Benzonase®, and one or more non-denaturing detergents including for example, N-lauroylsarcosinate. Other suitable non-denaturing detergents include N-lauroylsarcosinate, a polyoxyethylene alcohol, a polyoxyethylene isoalcohol, a polyoxyethylene p-t-octyl phenol, a polyoxyethylene nonyphenol, a polyoxyethylene ester of a fatty acid, and a polyoxyethylene sorbitol ester. Thereafter, the tissue is optionally washed with a hypotonic buffered salt solutions, optionally followed by washing with a hypertonic salt solution. Thereafter, the tissue is washed with water, and optionally followed by a wash of water optionally containing one or more decontaminating agents, such decontaminating agents including for example, chlorine dioxide, and alcohol. The decontaminated devitalized tissue produced is then stored in a storage solution in a sealed container, the storage solution optionally containing one or more decontaminating agents, such solutions including for example, isotonic saline; solutions of chlorine dioxide; alcohol solutions; isotonic solution containing one or more decontaminating agents, the decontaminating agents including for example low concentrations of chlorine dioxide or 70% isopropanol. The invention provides for the removal of cellular components without resultant damage to the matrix structure in which the cells resided, while ensuring that the repopulation enhancing large molecular weigh cytoplasmic proteins, including cytoskeletal proteins including for example, actin, are retained. Preferably, the soft tissue sample thickness does not exceed about 4 mm such that the time intervals described herein are sufficient for the solutions to penetrate the tissue. The concentration of endonuclease utilized is based on calculations designed at achieving a sufficient quantity of endonuclease within a given volume of tissue which is sufficient to digest the DNA within that volume of tissue and is not arbitrarily chosen based on volume of processing solution. The inventive process maintains the mechanical strength of the soft tissue graft biomaterials in part because the process does not detrimentally affect the matrix structure of the graft. The invention provides for the production of soft tissue grafts, which are readily repopulated by recipient cells, post implantation, or readily repopulated in vitro. The inventors surprisingly discovered producing a devitalized tissue which retains large molecular weight cytoplasmic proteins results in enhanced repopulation of the devitalized tissue graft post implantation. The inventors further discovered that the use of low salt concentrations in the tissues prior to or following treatment/extraction with a non-denaturing detergent results in essentially no residual detergent remaining in the tissue, and that this substantially complete removal of detergent also enhances repopulation, post implantation. Although the description of this invention is directed primarily at processing vascular graft materials, it should be appreciated that this invention can also be directed to processing non-vascular soft tissue grafts such as tendons, fascia, ligaments, pericardium, skin, dura, and cartilage by simple manipulation of processing times and parameters, such manipulation can be readily determined and employed by one of ordinary skill in the art, without undue experimentation. In the inventive process, normal healthy vessels (veins, arteries, heart valves, tendons, ligaments, fascia, pericardium, intestine, urethra, etc.) are surgically removed from animals or humans, transported to the processing facility where they are cleaned of extraneous matter and immediately submersed in an extracting solution which contains a hypotonic buffered solution containing one or more endonucleases including for example, Benzonase, and one or more non-denaturing detergents including for example, N-lauroylsarcosinate. In that most such vessels are procured at sites distant from the processing facility and that such vessels may ultimately either be cryopreserved or made devitalized, procurement and transport will normally be in a sterile container on wet ice in a solution iso-osmolar to the cellular population of the tissue being procured and transported. Furthermore, antibiotics are preferably added to the procurement and transport solution. One or more decontaminating agents, including for example, one or more antibiotics, can be optionally employed in any step of the inventive process, to maintain sterility of the procured tissues. FIG. 1 illustrates the processing of a long vein grafts ( 1 ), the distal end of the vein is cannulated onto the ribbed attachment ( 2 ) of the inlet port ( 3 ) and a single suture ( 4 ) is used to secure the vein. An additional suture line ( 5 ) is attached to the proximal end of the vein for later use in maintaining the vein in an extended state in the processing vessel ( 6 ). The vein ( 1 ) is then removed from the extracting solution and transferred to the processing vessel ( 6 ) that has been temporarily inverted. The second suture line ( 5 ) along with the vein ( 1 ) is passed through the processing vessel ( 6 ) and secured to a point ( 7 ) on the outlet port end ( 8 ) of the processing vessel ( 6 ). Prior to closing the processing vessel, a portion of the extracting solution is gently added to the processing vessel and the inlet port ( 3 ), with attached vein ( 1 ), is then secured. The processing vessel ( 6 ) is turned such that the inlet port ( 3 ) is down and the outlet port ( 8 ) is up and the vessel ( 6 ) is attached to its support racking system via clamps ( 9 ). Sterile disposable tubing ( 10 ) is attached to the inlet port ( 3 ) and to pump tubing in a peristaltic pump ( 11 ). Further, sterile disposable tubing ( 12 ) is attached to the inflow side ( 13 ) of the peristaltic pump ( 11 ) and to the solution reservoir ( 14 ) which will contain all remaining extracting solution. Finally, sterile disposable tubing ( 15 ) is attached between the top (outlet) port ( 8 ) of the processing vessel ( 6 ) and the solution reservoir ( 14 ). Sterile, in-line, filters ( 16 ) can optionally be added at appropriate positions in the fluid flow to safeguard sterility during processing. The extracting solution is pumped into, through and out of the processing vessel ( 6 ) such that flow of fluids through the luminal part of the vein tubule passes into the processing vessel ( 6 ) to affect constant solution change in the processing vessel and out through the outlet port ( 8 ) to a solution reservoir ( 14 ). By processing the vein in an inverted state, air which may be trapped in the luminal space of the vein will be induced to exit facilitating equal access of the processing solutions to the vein tissue being processed. Processing of the vein tissue with the extracting solution is preferably carried out at temperatures ranging from about 4° C. to about 42° C., preferably from about 20° C. to about 37° C., and most preferably from about 20° C. to about 27° C., for time periods ranging from about 1 hour to about 24 hours (overnight as necessary to accommodate processing scheduling of processing staff), preferably from about 6 hours to about 24 hours, and more preferably from about 12 hours to about 24 hours. The extracting solution is preferably pumped at a flow rate of from about 2 mls/min to about 200 mls/min, more preferably from about 5 mls/min to about 100 mls/min and most preferablly from about 30 mls/min to about 60 mls/min. The endonuclease (Benzonase) is optimally active between pH 6 and 10, and from 0° C. to above 42° C. (Merck literature describing product) when provided with 1-2 mM Mg +2 . Following processing with the extracting solution, the extracting solution can optionally be replaced with: a hypotonic salt solution; a hypotonic salt solution optionally followed by a hypertonic buffered salt solution; or a hypertonic salt solution; followed by processing with water. Thereafter, the tissue is processed with a decontaminating water solution optionally containing one or more decontaminating agents including for example, chlorine dioxide. Under the optional processing procedures, only sufficient solution need be circulated through the processing vessel to affect one volume change of solution in the processing vessel. Under the processing procedures with the hypertonic salt solution or with water, these solutions should be circulated through the tissue at a temperature of from 0° C. to about 42° C., preferably from about 20° C. to about 37° C., and most preferably from about 20° C. to about 27° C., for a time period of at least 3 hours, preferably from about 1 to about 24 hours, and most preferably from about 3 to about 6 hours. Following processing with the final processing solution, i.e. water or decontaminatingg water solution, sterile isotonic saline is circulated through the tissue such that the available volume of washing solution approximates a 1000-fold dilution of previous solutions. In this final processing step, the vein is removed from the processing vessel and transferred into storage solution, for example, 70% isopropanol, or 0.001% to 0.005% chlorine dioxide in sterile ultrapure water/isotonic saline, and packaged in a volume of storage solution sufficient to cover the tissue preventing dehydration. This packaged graft may then be terminally sterilized, for example using gamma irradiation, if so desired. Artery segments can be similarly processed, taking into consideration that veins have valves and arteries do not, and that veins generally have a smaller internal diameter than arteries, thus dictating slower flow rates with veins. FIG. 2 illustrates processing heart valve grafts. The heart valve ( 1 ) is placed into the deformable processing device ( 6 ') such that the valved end of the conduit is directed towards the inlet port ( 3 ) and the non-valved end of the conduit is directed towards the outlet port ( 8 ). Prior to closing the processing vessel ( 6 '), a portion of the extracting solution is gently added to the processing vessel. The processing vessel ( 6 ') is turned such that the inlet port ( 3 ) is down and the outlet port ( 8 ) is up to effect removal of air bubbles, and the vessel ( 6 ') attached to its support racking system via clamps ( 9 ). Sterile disposable tubing ( 10 ) is attached to the inlet port ( 3 )and to pump tubing in a peristaltic pump ( 11 ). Further, sterile disposable tubing ( 12 ) is attached to the inflow side ( 13 ) of the peristaltic pump ( 11 ) and to the solution reservoir ( 14 ) which will contain all remaining extracting solution. Finally, sterile disposable tubing ( 15 ) is attached between the top (outlet) port ( 8 ) of the processing vessel ( 6 ') and the solution reservoir ( 14 ). Sterile, in-line, filters ( 16 ) can optionally be added at appropriate positions in the fluid flow to safeguard sterility during processing. The extracting solution is pumped into, through and out of the processing vessel ( 6 ') such that the flow of fluids through the luminal part of the heart valve ( 1 ) passes into the processing vessel ( 6 ') to affect constant solution change in the processing vessel ( 6 ') and out through the outlet port ( 8 ) to a solution reservoir ( 14 ). By processing the heart valve ( 1 ) in this orientation, air which may be trapped in the luminal space of the valve will be induced to exit facilitating equal access of the processing solutions to the valve tissue being processed. Processing of the heart valve ( 1 ) tissue with the extracting solution is performed at for example, a temperature of from about 4° C. to about 42° C., preferably from about 20° C. to about 37° C., and most preferably from about 20° C. to about 27° C., for time periods ranging from about 1 hour to about 24 hours (overnight as necessary to accommodate processing scheduling of processing staff), preferably from about 6 hours to about 24 hours, and more preferably from about 12 hours to about 24 hours. The extracting solution is preferably pumped at a flow rate of from about 2 mls/min to about 200 mls/min, more preferably from about 5 mls/min to about 100 mls/min and most preferably from about 30 mls/min to about 60 mls/min. The endonuclease (Benzonase) is optimally active between pH 6 and 10, and from 0° C. to above 42° C. (Merck literature describing product) when provided with 1-2 mM Mg +2 . Following processing with the extracting solution, the extracting solution is optionally replaced with: a hypotonic salt solution; a hypotonic salt solution optionally followed by a hypertonic buffered salt solution; or a hypertonic salt solution; followed by processing with water. Thereafter, the tissue is processed with a decontaminating water solution optionally containing one or more decontaminating agents including for example, chlorine dioxide. Under the optional processing procedures, only sufficient solution (including the hypertonic salt solution) need be circulated through the processing vessel to affect one volume change of solution in the processing vessel. Under the processing procedures with water and/or disinfectant solutions, these solutions should be circulated through the tissue at a temperature of from 0° C. to about 42° C., preferably from about 20° C. to about 37° C., and most preferably from about 20° C. to about 27° C., for a time period of at least 3 hours, preferably from about 1 to about 24 hours, and most preferably from about 3 to about 6 hours. Following processing with the final processing solution, i.e. water or decontaminating water solution, sterile isotonic saline is circulated through the tissue such that the available volume of washing solution approximates a 1000-fold dilution of previous solutions. In this final processing step, the heart valve is removed from the processing vessel and transferred into storage solution, for example, 70% isopropanol, or 0.001% to 0.005% chlorine dioxide in sterile ultrapure water/isotonic saline, and packaged in a volume of storage solution sufficient to cover the tissue preventing dehydration. This packaged graft may then be terminally sterilized, for example using gamma irradiation, if so desired. For all other soft tissue grafts, the tissue is placed into the deformable processing device such that the smaller portion is directed towards the inlet port and the larger (bulkier) end of the tissue is directed towards the outlet port. Preferably the thickness of other soft tissue grafts does not exceed about 8 mm, more preferable does not exceed 5 mm, and most preferably the thickness does not exceed about 2-3 mm. If the thickness of the tissue graft exceeds about 5 mm, incubation and processing times need to be appropriately extended. Such incubation and processing times can be readily selected and employed by one of ordinary skill in the art to which the present invention pertains based on the thickness of the tissue being processed, the type of tissue being processed, and the volume of tissue being processed, without undue experimentation. Prior to closing the processing vessel, a portion of the extracting solution is gently added to the processing vessel. The processing vessel is then turned such that the inlet port is down and the outlet port is up and the vessel is attached to its support racking system for example, via clamps. Sterile disposable tubing is attached to the inlet port and to pump tubing in a peristaltic pump. Further, sterile disposable tubing is attached to the inflow side of the peristaltic pump and to the solution reservoir which will contain all remaining extracting solution. Finally, sterile disposable tubing is attached between the top (outlet) port of the processing vessel and the solution reservoir. Sterile, in-line, filters can optionally be added at appropriate positions in the fluid flow to safeguard sterility during processing. The extracting solution is pumped into, through and out of the processing vessel such that flow of fluids occurs in close proximity to the surfaces of the soft tissue grafts into the processing vessel to affect constant solution change in the processing vessel and out through the outlet port to a solution reservoir. By processing the soft tissue graft in this orientation, the bulkier portions of the soft tissue graft will receive the greatest flow of fluids across the surfaces facilitating equal access of the processing solutions to the tissue being processed. Processing of the soft tissue graft with the extracting solution is preferably performed at a temperature of from about 4° C. to about 42° C., preferably from about 20° C. to about 37° C., and most preferably from about 20° C. to about 27° C., for a period of time preferably of from about one hour to about 24 hours, (overnight as necessary to accommodate processing scheduling of processing staff), preferably from about 6 hours to about 24 hours, and more preferably from about twelve hours to about 18 hours. The extracting solution is preferably pumped at a flow rate of from about 2 mls/min to about 200 mls/min, more preferably from about 5 mls/min to about 100 mls/min and most preferablly from about 30 mls/min to about 60 mls/min. The endonuclease (Benzonase) is optimally active between pH 6 and 10, and from 0° C. to above 42° C. (Merck literature describing product) when provided with 1-2 mM Mg +2 . Following processing with the extracting solution, the extracting solution is optionally replaced with a hypertonic salt solution prior to replacement of the hypertonic salt solution with water. Under the optional processing procedure, only sufficient water or salt solution need be circulated through the processing vessel to affect one volume change of solution in the processing vessel. Under processing with the various solutions, these solutions are circulated through and/or around the tissue at a temperature of from about 4° C. to about 42° C., preferably from about 20° C. to about 37° C., and most preferably from about 20° C. to about 27° C., for a time period of at least 3 hours, preferably from about 1 to about 24 hours, and most preferably from about 3 to about 6 hours. Following optional processing with the hypertonic salt solution, water for example ultrapure sterile water, or isotonic saline, is circulated through and/or around the tissue and processing vessel such that the available volume of washing solution approximates a 1000-fold dilution of the previous processing solutions. Following the water wash, the tissue is optionally processed with a decontaminating solution. Throughout processing for all tissue grafts, the tissue is processed at a flow rate sufficient to affect a volume change in the processing vessel about every 30-40 minutes, suitable flow rates including for example of from about 2 mls/min to about 200 mls/min, preferably from about 5 mls/min to about 100 mls/min, more preferably from about 30 mls/min. to about 70 mls/min., even more preferably from about 40 mls/min to about 60 mls/min., and most preferably about 50 mls/min. Following washing with the decontaminating solution, the soft tissue graft may be removed from the processing vessel and transferred into storage solution containing for example, buffered isotonic saline, 70% isopropanol, or 0.0005% to 0.005%, preferably 0.001% chlorine dioxide in sterile ultrapure water/isotonic saline, and packaged in a volume of storage solution sufficient to cover the tissue preventing dehydration. Alternatively, the storage solutions can be pumped into the processing vessel until the decontaminating solution has been adequately exchanged and the whole processing vessel sealed, sterilized for example using gamma-irradiation, and used as the storage container for distribution. Storage of processed soft tissue grafts should be in a solution which covers the graft and which is contained in a container that will prevent evaporation and fluid loss or concentration of solutes. The solution can be isotonic saline, isotonic saline or ultrapure water containing a preservative such as chlorine dioxide, isopropanol, METHYLPARABIN® (Croda, Inc.), antibiotics, antimicrobials, antimycotic agents, antifungal agents, or ultrapure water, or similar bacteriostatic or bacteriocidal agent which do not biologically alter the matrix components of the soft tissue grafts. Suitable storage solutions are well known to those of ordinary skill in the art to which the present invention applies, and such solutions can be readily selected and employed by those of ordinary skill in the art to which the present invention applies without undue experimentation. The storage containers with solution and soft tissue grafts can be terminally sterilized using methods known in the art including but not limited to, gamma irradiation at doses up to 2.5 Mrads. The following examples illustrate processing of soft tissue grafts according to the invention. EXAMPLE 1 Saphenous vein tissues (two) from each leg of an acceptable human donor were carefully dissected under sterile conditions to remove all visible fat deposits and the side vessels were tied off using non-resorbable suture materials such that the ties did not occur in close proximity to the long run of the vessel. Sutures can restrict the devitalization process and the tissues under the sutures were removed following devitalization. For long vein grafts (40-60 cm) (FIG. 1 ), the distal ends of the veins were cannulated onto the ribbed attachment of the inlet port(s) and single sutures used to secure each vein. Additional suture lines were attached to the proximal ends of the veins. The veins were then removed from the dissecting solution (ultrapure water containing 50 mM Tris-HCl (pH 7.2), 5 mM EDTA, and one or more antibiotics) and transferred to the processing vessel which had been temporarily inverted. The second suture line along with the vein was passed through the processing vessel and secured to a point on the outlet port end of the processing vessel. Prior to closing the processing vessel, a portion of the extracting solution was gently added to the processing vessel and the inlet port, with attached vein, was then secured. The processing vessel was then turned such that the inlet port was down and the outlet port was up and the vessel attached to its support racking system via clamps. Sterile disposable tubing was attached to the inlet port and to pump tubing in a peristaltic pump. Further, sterile disposable tubing was attached to the inflow side of the peristaltic pump and to the solution reservoir which contained all remaining extracting solution. Total extracting solution volume approximated 250 ml. Finally, sterile disposable tubing was attached between the top (outlet) port of the processing vessel and the solution reservoir. Sterile, in-line, filters were added at appropriate positions in the fluid flow to safeguard sterility during processing. The extracting solution was then pumped into, through and out of the processing vessel such that flow of fluids through the luminal part of the vein tubule passed into the processing vessel to affect constant solution change in the processing vessel and out through the outlet port to a solution reservoir. By processing the vein in an inverted state, air which had been “trapped” in the luminal space of the vein was induced to exit facilitating equal access of the processing solutions to the vein tissue being processed. Processing of the vein tissue with the extracting solution was performed at 25±5° C. for 16 hours using a flow rate of the extracting solution of 50 mls/min. The extracting solution consisted of 50 mM Tris HCL (pH 8), 2 mM MgCl 2 , 1% (w:v) N-lauroyl sarcosinate, and endonuclease (Benzonase, a registered product of EM Industries, Inc.) (41.8 Units/ml). Following processing with the extracting solution, the extracting solution was replaced with a hypertonic salt solution, preferably 0.5M NaCl (250 mls at a pump rate of 50 mls/min.) over a period of one hour. Only sufficient salt solution was circulated through the processing vessel to affect one volume change of solution in the processing vessel. Following processing with the decontaminating solution, the vein was removed from the processing vessel and transferred into storage solution of 0.001% chlorine dioxide in sterile ultrapure water and packaged in a volume of this solution sufficient to cover the tissue. Following processing with the decontaminating solution, the vein was removed from the processing vessel and transferred into storage solution of 0.001% chlorine dioxide in sterile ultrapure water and packaged in a volume of this solution sufficient to cover the tissue. Following devitalization, representative sections of the tissue were removed and fixed in buffered formalin and embedded for preparation of histology slides. When stained using standard hemotoxalin/eosin, Mason's Trichrome, etc., the tissues were found to be devoid of visible cellular remnents, however the medial layer typically stained “pink” (Mason's trichrome stain) indicative of residual cytoplasmic proteins. Innumohistochemical staining of these tissues revealed these pink stained areas to contain residual high molecular weitht cytoplasmic proteins (actins). EXAMPLE 2 Saphenous vein tissues (two) from each leg of an acceptable human donor were carefully dissected under sterile conditions to remove all visible fat deposits and side vessels were tied off using nonresorbable suture materials such that the ties did not occur in close proximity to the long run of the vessel. Sutures can restrict the decellularization process and the tissues under the sutures were removed following decellularization. For these long vein grafts (33 and 28 cm) (FIG. 1 ), the distal ends of the veins were cannulated onto the ribbed attachment of the inlet port(s) and single sutures used to secure each vein. Additional suture lines were attached to the proximal ends of the veins. At this point, the veins were removed from the dissecting solution (ultrapure water containing 50 mM Tris-HCl (pH 7.2), 5 mM EDTA, and one or more antibiotics and transferred to the processing vessel which had been temporarily inverted. The second suture line along with the vein was passed through the processing vessel and secured to a point on the outlet port end of the processing vessel. Prior to closing the processing vessel, a portion of the extracting solution was gently added to the processing vessel and the inlet port, with attached vein, was then secured. The processing vessel was then turned such that the inlet port was down and the outlet port was up and the vessel attached to its support racking system via clamps. Sterile disposable tubing was attached to the inlet port and to pump tubing in a peristaltic pump. Further, sterile disposable tubing was attached to the inflow side of the peristaltic pump and to the solution reservoir which contained all remaining first extracting solution. Total processing solution volume approximated 250 ml. Finally, sterile disposable tubing was attached between the top (outlet) port of the processing vessel and the solution reservoir. Sterile, in-line, filters were added at appropriate positions in the fluid flow to safeguard sterility during processing. The extracting solution was pumped into, through and out of the processing vessel such that flow of fluids through the luminal part of the vein tubule passed into the processing vessel to affect constant solution change in the processing vessel and out through the outlet port to a solution reservoir. By processing the vein in an inverted state, air which had been “trapped” in the luminal space of the vein was induced to exit facilitating equal access of the processing solutions to the vein tissue being processed. Processing of the vein tissue with the extracting solution was performed at 25±5° C. for 16 hours using a flow rate of the extracting solution of 50 mls/min. The extracting solution consisted of 50 mM Tris-HCl (pH 7.2), 2 mM MgCl 2 , 0.1% (w:v) n-lauroyl sarcosinate, and endonuclease (Benzonase, a registered product of EM Industries, Inc.) (41.8 Units/ml). Following processing with the extracting solution, the extracting solution was replaced with a hypertonic salt solution containing 1.0M KCL (50 mls/min. flow rate) through the tissue at room temperature (25±5° C.) for a time period of 3 hours. Following processing with the hypertonic salt solution, ultrapure sterile water was circulated through the tissue and processing vessel such that the available volume of washing solution approximated a 1000-fold dilution of the salt solution with a flow rate of 50 mls/min. for 1.5 hours. Following washing in this final processing step, the vein was removed from the processing vessel and transferred into storage solution of 0.001% chlorine dioxide in sterile ultrapure water and packaged in a volume of this solution sufficient to cover the tissue. Following devitalization, representative sections of the tissue were removed and fixed in buffered formalin and embedded for preparation of histology slides. When stained using standard hemotoxalin/eosin, Mason's Trichrome, etc., the tissues were found to be devoid of visible cellular remnents, however the medial layer typically stained “pink” (Mason's trichrome stain) indicative of residual cytoplasmic proteins. Immunohistochemical staining of these tissues revealed these pink stained areas to contain residual high molecular weight cytoplasmic proteins (actins). EXAMPLE 3 Internal mammary artery tissues (two) from an acceptable human donor were carefully dissected under sterile conditions to remove all visible fat deposits and side vessels were tied off using nonresorbable suture materials such that the ties did not occur in close proximity to the long run of the vessel. Sutures can restrict the decellularization process and the tissues under the sutures were removed following decellularization. For short artery grafts (11 and 8 cm) (FIG. 1 ), one end of each artery were cannulated onto the ribbed attachment of the inlet port(s) and single sutures used to secure each arteries. The arteries were then removed from the dissecting solution (ultrapure water containing 50 mM Tris-HCl (pH 7.2), 5 mM EDTA, and one or more antibiotics) and transferred to the processing vessel which had been temporarily inverted. Prior to closing the processing vessel, a portion of the extracting solution was gently added to the processing vessel and the inlet port, with attached artery, was then secured. At this point, the processing vessel was turned such that the inlet port was down and the outlet port was up and the vessel attached to its support racking system via clamps. Sterile disposable tubing was attached to the inlet port and to pump tubing in a peristaltic pump. Further, sterile disposable tubing was attached to the inflow side of the peristaltic pump and to the solution reservoir which contained all remaining extracting solution. Total processing solution volume approximated 150 ml. Finally, sterile disposable tubing was attached between the top (outlet) port of the processing vessel and the solution reservoir. Sterile, in-line, filters were added at appropriate positions in the fluid flow to safeguard sterility during processing. The extracting solution was pumped into, through and out of the processing vessel such that flow of fluids through the luminal part of the artery tubule passed into the processing vessel to affect constant solution change in the processing vessel and out through the outlet port to a solution reservoir. By processing the artery in an inverted state, air which had been “trapped” in the luminal space of the vein was induced to exit facilitating equal access of the processing solutions to the vein tissue being processed. Processing of the artery tissue with the extracting solution was performed at 25±5° C. for 16 hours using a flow rate of the extracting solution of 50 mls/min. The extracting solution consisted of 50 mM Tris-HCl (pH 7.2), 5 mM MgCl 2 , 0.01% (w:v) N-lauryl sarcosinate, and endonuclease (Benzonase, a registered product of EM Industries, Inc.) (41.8 Units/ml). Following processing with extracting solution, the extracting solution was replaced with a hypertonic salt solution of 0.5 KCL in sterile ultrapure water (250 mls at a pump rate of 60 mls/min.) which was then replaced with ultrapure water buffered with 50 mM Tris-HCl (pH 7.2). Under this processing procedure, only sufficient ultrapure water was circulated through the processing vessel to affect one volume change of solution in the processing vessel. Under the processing with water solution, this water solution was circulated (flow rate of 30 mls/min.) through the tissue at room temperature (25±5° C.), for a time period of 3 hours. Following processing with the second processing solution, ultrapure sterile water was circulated through the tissue and processing vessel such that the available volume of washing solution approximated a 1000-fold dilution of the KCL present in the hypertonic salt solution with a flow rate of 50 ml/min. for 1.5 hours. Following washing in this final processing step, the artery was removed from the processing vessel and transferred into storage solution of 70% (v:v) pharmaceutical grade isopropanol in sterile ultrapure water and packaged in a volume of this solution sufficient to cover the tissue. Following devitalization, representative sections of the tissue were removed and fixed in buffered formalin and embedded for preparation of histology slides. When stained using standard hemotoxalin/eosin, Mason's Trichrome, etc., the tissues were found to be devoid of visible cellular remnents, however the medial layer typically stained “pink” (Mason's trichrome stain) indicative of residual cytoplasmic porteins. Immunohistochemical staining of these tissues revealed these pink staind areas to contain residual high molecular weight cytoplasmic proteins (actins). EXAMPLE 4 Aortic and pulmonary tissues (one each) from a heart of an acceptable human donor were carefully dissected under sterile conditions to remove all visible fat deposits and cardiac muscle tissue (leaving only a small but visible band of cardiac muscle tissue around the proximal end of the conduit. The valves were then removed from the dissecting solution (ultrapure water containing 50 mM Tris-HCl (pH 7.2), 5 mM EDTA, and one or more antibiotics) and transferred to the deformable (plastic) processing vessel (FIG. 2 ). Prior to closing the processing vessel, a portion of the extracting solution was gently added to the processing vessel and the side access port closed using the clamping mechanism illustrated in FIG. 2 . The proximal end of the heart valve(s) was placed towards the inlet port and the distal end(s) of the valve was placed towards the outlet port. At this point, the processing vessel was placed such that the inlet port was down and the outlet port was up and the vessel attached to its support racking system via clamps. Sterile disposable tubing was attached to the inlet port and to pump tubing in a peristaltic pump. Further, sterile disposable tubing was attached to the inflow side of the peristaltic pump and to the solution reservoir which contained all remaining extracting solution. Total processing solution volume approximated 350 ml. Finally, sterile disposable tubing was attached between the top (outlet) port of the processing vessel and the solution reservoir. Sterile, in-line, filters were added at appropriate positions in the fluid flow to safeguard sterility during processing. The extracting solution was pumped into, through and out of the processing vessel such that flow of fluids through the luminal part of the heart valve tubule passed into the processing vessel to affect constant solution change in the processing vessel and out through the outlet port to a solution reservoir. By processing the heart valve in an noninverted state, air which had been “trapped” in the luminal spaces behind the leaflets of the heart valve was induced to exit facilitating equal access of the processing solutions to the heart valve tissue being processed. Processing of the valve and conduit tissue with the extracting solution was performed at 25±5° C. for 16 hours using a flow rate of the extracting solution of 50 mls/min.. The extracting solution consisted of 50 mM Tris-HCl (pH 7.2), 2 mM MgCl 2 , 1% (w:v) N-lauroylsarcosinate, and endonuclease (Benzonase, a registered product of EM Industries, Inc.) (41.8 Units/ml). Following processing with the extracting solution, the extracting solution was replaced with sterile ultrapure water (350 mls at a pump rate of 50 mls/min. being recirculated over a time period of 3 hours). Under this processing procedure, only sufficient ultrapure water was circulated through the processing vessel to affect one volume change of solution in the processing vessel. When optionally processing with salt solution, the hypertonic salt solution is circulated (flow rate of 30 mls/min.) through the tissue at room temperature (25±5° C.), for a time period of 5 hours. Following washing in this final processing step, the heart valve(s) was (were) removed from the processing vessel and transferred into storage solution of 0.05% chlorine dioxide in sterile ultrapure water and packaged in a volume of this solution sufficient to cover the tissue. Following devitalization, representative sections of the tissue were removed and fixed in buffered formalin and embedded for preparation of histology slides. When stained using standard hemotoxalin/eosin, Mason's Trichrome, etc., the tissues were found to be devoid of visible cellular remnents, however the medial layer typically stained “pink” (Mason's trichrome stain) indicative of residual cytoplasmic porteins. Immunohistochemical staining of these tissues revealed these pink staind areas to contain residual high molecular weight cytoplasmic proteins (actins). EXAMPLE 5 In this example, artery tissues were processed according to the procedure described by Klement and Brendel (U.S. Pat. No. 4,776,853) using gentle aggitation in closed vessels. The tissues were treated for 18 hours in a slightly alkaline buffered solution containing the chelating agent EDTA. The tissues were then incubated, again in a closed container, in a solution of 1% Triton X-100 containing DNase and RNase at the quantities and volumes described for 48 hours. The tissues were then incubated, again in a closed container, in a hypotonic solution of 1% sodium laurylsulfate (SDS) for 72 hours at the volumes described by Klement and Brendel. Following these steps, the tissues were incubated in a hypertonic salt solution using the volumes and time described and then transferred to isotonic saline to remove the hypertonic salt solutions. Following decellularization, representative sections of the tissue were removed and fixed in buffered formalin and embedded for preparation of histology slides. When stained using standard hemotoxalin/eosin, Mason's Trichrome, etc., the tissues were found to be devoid of visible cellular remnents and the medial layer did not stain “pink” (Mason's trichrome stain) indicative of an absence of residual cytoplasmic proteins. Immunohistochemical staining of these tissues revealed an absence of residual high molecular weight cytoplasmic proteins (actins) conforming to the specifications of Klement and Brendel in the production of a totally decellularized, as per their specification, tissue. While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come hypotonic buffered within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth as follows in the scope of the appended claims. Any references including patents cited herein are incorporated herein in their entirety.

The invention provides methodologies and apparatus for producing devitalized soft-tissue implants where the implant retains metabolically non-viable and/or reproductively non-viable cells, and preferably retains large molecular weight cytoplasmic proteins, such implants produced both in small quantities and in commercializable quantities. Such soft-tissue implants include vascular graft substitutes. An devitalized graft is produced by subjecting the tissue sample to an induced pressure mediated flow of an extracting solution, optionally followed by inducing a pressure mediated flow of a salt solution, then washing the tissue to produce the devitalized graft. The devitalized grafts produced are uniform and non-immunogenic. The inventive method allows for the production of multiple devitalized soft tissue implants, where processing time is significantly less than prior art processes and the number of implants produced per day is increased over prior art processes. In clinical use, the devitalized grafts produced exhibit significantly improved in long-term durability and function, and enhanced recellularization post-implantation.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-106918, filed Apr. 9, 2002, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display control device and a method of preparing patterns for the same device. 2. Description of the Related Art A frame modulation gradation display method has been known as the gradation display method of a matrix type liquid crystal display panel (LCD panel). According to the above frame modulation method, gradation display is possible on the LCD panel even if a single pixel only makes binary display (on display and off display). According to the frame modulation method, on display and off display are properly combined in the time axis direction, and thereby, pseudo gradation display is possible. For example, if a 16-gradation level image is displayed, 16 frames are set as one cycle, and on frame and off frame are determined in accordance with gradation level. As a result, a desired gradation is obtained as the mean value of 16 frames. As described above, according to the frame modulation method, several frames are set as one cycle. For this reason, the number of gradation levels increases, and thereby, flicker conspicuously appears; as a result, display quality worsens. Thus, if the 16-gradation level image is displayed, a display pattern is formed using 4 horizontal direction pixels and 4 vertical direction pixels, that is, the total 4×4=16 pixels. By doing so, the display quality can be prevented from deteriorating. The following is a description on memory capacity required for storing the above display pattern. For example, if the 16-gradation level image is displayed, the following memory capacity is required. The memory capacity is 4096 bits=16 (the number of pixels in a display pattern)×16 (the number of frames)×16 (the number of gradation levels). If a microcomputer having built-in memory performs display control, preferably, the number of bits for storing the display pattern is reduced as much as possible because the number of bits of the built-in memory is limited. In the frame modulation method, the display pattern for each gradation level is not necessarily optimized. For this reason, there is a problem that display quality worsens. As described above, conventionally, there are problems that the memory capacity for storing the display pattern becomes much, and the display pattern is not optimized. BRIEF SUMMARY OF THE INVENTION According to a first aspect of the present invention, there is provided a liquid crystal display control device for making gradation display on a liquid crystal display panel using binary display patterns, comprising: a memory section storing a plurality of pattern data items for a plurality of gradation levels, each of the pattern data items defining a plurality of binary display patterns set for a plurality of basic frames, and each of the binary display patterns being defined by a plurality of basic pixels; and a selector section selecting one of the pattern data items, which corresponds to a designated gradation level; wherein the number of the basic frames and the number of the basic pixels for each of the gradation levels are predetermined and depend on each of the gradation levels. According to a second aspect of the present invention, there is provided a method of preparing binary display patterns used for making gradation display on a liquid crystal display panel, a plurality of the binary display patterns being set for a plurality of basic frames, and each of the binary display patterns being defined by a plurality of basic pixels, comprising: determining a darkest basic pixel in a basic frame; lighting the darkest basic pixel; obtaining a binary display pattern for the basic frame by repeating the determining a darkest basic pixel and the lighting the darkest basic pixel; determining whether binary display patterns for all basic frames satisfy a predetermined condition; performing, in a next basic frame, the determining a darkest basic pixel to the determining whether binary display patterns for all basic frames satisfy a predetermined condition, when it is not determined that the binary display patterns for all basic frames satisfy the predetermined condition; and determining the binary display patterns satisfying the predetermined condition as final binary display patterns, when it is determined that the binary display patterns for all basic frames satisfy the predetermined condition. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a block diagram showing the configuration of a liquid crystal display control device according to an embodiment of the present invention; FIG. 2A to FIG. 2D are views each showing a basic pixel group according to an embodiment of the present invention; FIG. 3A to FIG. 3D are views each showing an arrangement of the basic pixel group according to an embodiment of the present invention; FIG. 4 is a view showing display patterns according to an embodiment of the present invention; FIG. 5 is a view to explain the detailed configuration and operation of the liquid crystal display control device according to an embodiment of the present invention; FIG. 6 is a view showing an arrangement of the basic pixel group according to an embodiment of the present invention; FIG. 7 is a view showing a brightness change of pixel according to an embodiment of the present invention; and FIG. 8 is a flowchart showing a method of obtaining the optimal display pattern according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. (First Embodiment) The following is a description on the case where a 16-gradation image is displayed on a matrix type liquid crystal display panel in which only binary display is made in a single pixel. If the 16-gradation image is displayed, there exist the total 17 gradation levels from the case where all pixels are off state (0 gradation level) to the case where all pixels are on state (16-th gradation level). In the embodiment, the 15-th gradation level (the case where 15 pixels are on state) is not used so that the total number of gradation levels becomes 16. FIG. 1 is a block diagram showing the configuration of a liquid crystal display control device according to the first embodiment. The liquid crystal display control device includes a control section 11 , a memory section (look-up table) 12 , and a selector section 13 . The memory section 12 stores binary display patterns (hereinafter, referred simply to display patterns) of each gradation level. The selector section 13 selects pattern data (set of display patterns) corresponding to the designated gradation level. The above constituent elements are built in a single IC chip. In the first embodiment, the number of pixels (basic pixels) forming the display pattern is predetermined depending on gradation level. In addition, the number of display patterns (the number of basic frames) is predetermined depending on gradation level. For example, if the number of basic pixels is 4, one cycle includes 4 basic frames, and the number of basic frames is 4. More specifically, as shown in FIG. 2A to FIG. 2D , in the first, third, fifth, seventh, ninth, 11th and 13th gradation levels (hereinafter, referred to as first type) (see FIG. 2A ), the basic pixel group is composed of 4×4=16 pixels, and the number of basic frames is 16. In the second, sixth, tenth and 14th gradation levels (hereinafter, referred to as second type)(see FIG. 2B ), the basic pixel group is composed of 4×2=8 pixels, and the number of basic frames is 8. In the fourth and 12th gradation levels (hereinafter, referred to as third type) (see FIG. 2C ), the basic pixel group is composed of 2×2=4 pixels, and the number of basic frames is 4. In the eighth gradation level (hereinafter, referred to as fourth type) (see FIG. 2D ), the basic pixel group is composed of 2×1=2 pixels, and the number of basic frames is 2. In FIG. 2A to FIG. 2D , (i, j) shown in each pixel is each pixel position of X and Y directions in the basic pixel group. FIG. 3A to FIG. 3D show the arrangement of each basic pixel group of the above first to fourth types. FIG. 3A to FIG. 3D show the first to fourth types, respectively. FIG. 4 shows display patterns of basic frames set for the seventh gradation level. As seen from FIG. 4 , in each basic frame, seven pixels are on state. Any pixels included in the basic pixel group are on state in seven of 16 frames. Here, the total memory capacity when the above method is employed is as follows. In the first type, the memory capacity is 1792 bits=16 (the number of pixels in a display pattern)×16 (the number of frames)×7 (the number of gradation levels). In the second type, the memory capacity is 256 bits=8 (the number of pixels in a display pattern)×8 (the number of frames)×4 (the number of gradation levels). In the third type, the memory capacity is 32 bits=4 (the number of pixels in a display pattern)×4 (the number of frames)×2 (the number of gradation levels). In the fourth type, the memory capacity is 4 bits=2 (the number of pixels in a display pattern)×2 (the number of frames)×1 (the number of gradation levels). Therefore, the total memory capacity is 2084 bits=1792+256+32+4. As a result, the total memory capacity is reduced to nearly half of the conventional memory capacity (4096 bits). Pattern data can be used in common for gradation level expressed by (8−c) and gradation level expressed by (8+c). That is, each display pattern of the (8−c) gradation level is obtained by inverting each display pattern of the (8+c) gradation level (on display pixel is inverted to off display pixel, off display pixel is inverted to on display pixel). As described above, the pattern data is used in common, and thereby, the memory capacity can be further reduced. More specifically, in the first type, the pattern data of seventh and ninth gradation levels is used in common, the pattern data of fifth and 11th gradation levels is used in common, and the pattern data of third and 13th gradation levels is used in common, and thereby, the memory capacity is 1024 bits. In the second type, the pattern data of sixth and tenth gradation levels is used in common, and the pattern data of second and 14th gradation levels is used in common, and thereby, the memory capacity is 128 bits. In the third type, the pattern data of fourth and 12th gradation levels is used in common, and thereby, the memory capacity is 16 bits. In the fourth type, the memory capacity is 4 bits as already described. Therefore, the total memory capacity is 1172 bits=1024+128+16+4, so that the memory capacity can be greatly reduced. FIG. 5 is a view to explain the detailed configuration and operation of the liquid crystal display control device according to the first embodiment. In FIG. 5 , 21 a to 21 d correspond to a memory section (look-up table) storing display patterns. The 21 a is a memory part storing display patterns of the first, third, fifth, seventh, ninth, 11th and 13th gradation levels (first type). The 21 b is a memory part storing display patterns of the second, sixth, tenth and 14th gradation levels (second type). The 21 c is a memory part storing display patterns of the fourth and 12th gradation levels (third type). The 21 d is a memory part storing display patterns of the eighth gradation level (fourth type). A reference numeral 22 denotes a selector section for selecting the display pattern from the above memory parts 21 a to 21 d . Reference numerals 23 a to 23 c denotes operation parts, 24 denotes a 4-bit counter. The 4-bit counter 24 inputs frame pulse, and outputs 4-bit count value k[3:0]. The operation part 23 a inputs 4-bit count value k[3:0] and data j[1:0] expressing lower 2 bits of the Y coordinate value of the current pixel. The operation result (4×k+j) in the operation part 23 a is outputted to the memory part 21 a as address data. The memory part 21 a outputs 4-bit data stored in the designated address. The operation part 23 b inputs lower 3-bit k[2:0] of the count value and lower 1 bit j[0] of the Y coordinate value. The operation result (2×k[2:0]+j[0]) in the operation part 23 b is outputted to the memory part 21 b as address data. The memory part 21 b outputs 4-bit data stored in the designated address. The operation part 23 c inputs lower 2-bit k[1:0] of the count value and lower 1-bit j[0] of the Y coordinate value. The operation result (2×k[1:0]+j[0]) in the operation part 23 c is outputted to the memory part 21 c as address data. The memory part 21 c outputs 4-bit data converted from 2-bit data stored in the designated address. The memory part 21 d inputs lower 1-bit k[0] of the count value as address data. The memory part 21 d outputs 4-bit data converted from 2-bit data stored in the designated address. According to the above operation, data of each gradation level L stored in the memory parts 21 a to 21 d is inputted to the selector section 22 . In FIG. 5 , for example, the first gradation level data of the first type is expressed as T 1 (for L=1), and the second gradation level data of the second type is expressed as T 2 (for L=2). 4-bit data expressing each gradation level of three primary colors (R gradation level L (R), G gradation level L (G), B gradation level L (B)), are inputted to the selector section 22 from the outside. In addition, lower 2-bit i[1:0] of the X coordinate value of the current pixel is inputted to the selector section 22 . Based on the above data, 1-bit output data (Rout, Gout, Bout) of each primary color is successively outputted from the selector section 22 . That is, if the gradation level belongs to the first to fourth types (i.e., first to 14th gradation levels), any one of data from the memory parts 21 a to 21 d is selected, and data selected by lower 2-bit i[1:0] of the X coordinate value is successively outputted. If the gradation level is 0-gradation level, off-display state data (logical value 0) is outputted. If the gradation level is the 16th gradation level, on-display state data (logical value 1) is outputted. As seen from the above description, according to the first embodiment, the number of basic frames and the number of basic pixels are preset in accordance with the gradation level. By doing so, it is possible to greatly reduce the memory capacity for storing display patterns. Therefore, in particular, it is effective in the case where the microcomputer having built-in memory carries out the display control of the liquid crystal display panel. The above embodiment has described the case of displaying image having the total gradation level number N of 16 (N=16). However, the total gradation level number N is not limited. For example, there exists gradation level expressed by (N/a)×b (where, a and N/a are an integer of 2 or more, b is an integer larger than 0 and smaller than a). In this case, the number of basic frames and the number of basic pixels are both set as a; therefore, the memory capacity can be effectively reduced. In addition, if the total gradation level number N is expressed by n 2 (where, n is an integer of 2 or more), the basic pixel group is composed of n×n (X-direction n pixels, Y-direction n pixels), so that deterioration of display quality can be prevented. If n 2 is an odd number, it is preferable that the total gradation level number N is N=n 2 +1. When the pattern data is used in common, c is set as an integer larger than 0 and smaller than N/2, it is preferable that common pattern data is used for gradation level expressed by c and gradation level expressed by N−c. (Second Embodiment) The following is a description on the method of obtaining the optimal display pattern in each gradation level. Matters overlapping with those described in the first embodiment are omitted. FIG. 6 shows an arrangement of the basic pixel group for the first, third, fifth, seventh, ninth, 11th and 13th gradation levels (first type). The following is a description on the brightness of the central pixel, for example, a pixel (0, 0) shown in the circle of FIG. 6 . The actual brightness of the central pixel receives the influence by the brightness of surrounding pixels, in addition to the self-brightness thereof. For instance, the self-brightness of pixel (i, j) is set as g 1 [j][i], and the actual brightness of pixel (i, j) receiving the influence by the brightness of surrounding pixels is set as g 2 [j][i]. In this case, g 2 [j][i] can be expressed by the following equation (1). g2 ⁡ [ j ] ⁡ [ i ] = g1 ⁡ [ C ⁡ ( j ) ] ⁡ [ C ⁡ ( i ) ] + ( g1 ⁡ [ C ⁡ ( j ) ] ⁡ [ C ⁡ ( i + 1 ) ] + ⁢ g1 ⁡ [ C ⁡ ( j ) ] ⁡ [ C ⁡ ( i - 1 ) ] + g1 ⁡ [ C ⁡ ( j + 1 ) ] ⁡ [ C ⁡ ( i ) ] + g1 ⁡ [ C ⁡ ( j - 1 ) ] ⁡ [ C ⁡ ( i ) ] ) / ⁢ ( Kc ⁡ ( 2 ) ) + 2.0 * ( g1 ⁡ [ C ⁡ ( j ) ] ⁡ [ C ⁡ ( i + 2 ) ] + g1 ⁡ [ C ⁡ ( j + 2 ) ] ⁡ [ C ⁡ ( i ) ] ) / ⁢ ( Kc ⁡ ( 4 ) ) + ( g1 ⁡ [ C ⁡ ( j ) ] ⁡ [ C ⁡ ( i + 3 ) ] + g1 ⁡ [ C ⁡ ( j ) ] ⁡ [ C ⁡ ( i - 3 ) ] + ⁢ g1 ⁡ [ C ⁡ ( j + 3 ) ] ⁡ [ C ⁡ ( i ) ] + g1 ⁡ [ C ⁡ ( j - 3 ) ] ⁡ [ C ⁡ ( i ) ] / ( Kc ⁡ ( 6 ) ) + ⁢ ( g1 ⁡ [ C ⁡ ( j + 1 ) ] ⁡ [ C ⁡ ( i + 1 ) ] + g1 ⁡ [ C ⁡ ( j + 1 ) ] ⁡ [ C ⁡ ( i - 1 ) ] + g1 ⁡ [ C ⁡ ( j - 1 ) ] ⁢ [ C ⁡ ( i + 1 ) ] + g1 ⁡ [ C ⁡ ( j - 1 ) ] ⁡ [ C ⁡ ( i - 1 ) ] ) / ( Kc ⁡ ( sqrt ⁡ ( 8 ) ) ) + ⁢ 4.0 * g1 ⁡ [ C ⁡ ( j + 2 ) ] ⁡ [ C ⁡ ( i + 2 ) ] / ( Kc ⁡ ( sqrt ⁡ ( 32 ) ) ) + ⁢ 2.0 * ( g1 ⁡ [ C ⁡ ( j + 1 ) ] ⁡ [ C ⁢ ( i + 2 ) ] + g1 ⁡ [ C ⁡ ( j - 1 ) ] ⁡ [ C ⁡ ( i + 2 ) ] + ⁢ g1 ⁡ [ C ⁡ ( j + 2 ) ] ⁡ [ C ⁡ ( i + 1 ) ] + g1 ⁡ [ C ⁡ ( j + 2 ) ] ⁡ [ C ⁡ ( i - 1 ) ] ) / ( Kc ⁡ ( sqrt ⁡ ( 20 ) ) ) ( 1 ) Where, Kc(r2/r1)=(r2/r1) r (1.5≦r≦2.5) In the above equation (1), r 1 is a radius when on-pixel (lighting pixel) is assumed as being a sphere, and r 2 is a distance from on-pixel. The value of r is theoretically 2. C(i) means “i mod 4”, for example, C(1)=C(5)=C(−3). The above “sqrt” means square root. The brightness of a certain frame of a certain pixel receives the influence of the frame before it. For example, as shown in FIG. 7 , when a certain pixel continuously becomes on state, the brightness of the certain pixel gradually increases. Assuming that the brightness of a certain frame of a certain pixel is set as g 1 (j,i), the brightness g 1 (j,i)next of the nest frame is expressed by the following equation (2). g 1 ( j,i )next= g 1 ( j,i )*(1 −Kr )+ Kr*Ps ( j,i )  (2) Where, 0.05≦Kr≦0.2, and in general, Kr=0.1. Ps(j,i) is 1 if pixel is on state while being 0 if pixel is off state. The method of obtaining the optimal display pattern will be described below with reference to the flowchart shown in FIG. 8 . Here, the case of obtaining the display pattern of the seventh gradation level shown in FIG. 4 will be described. In step S 1 , the initial setting is made. That is, the number of basic frames is set to 16, the number of pixels included in the basic pixel group is set to 16, and the number of on-pixels in the basic pixel group is set to 7. In addition, a pixel, which first becomes on state, is temporarily set in the basic pixel group of the first frame. In this case, the pixel is on state, that is, g 1 (0,0)=1; on the other hand, other pixels are off state, that is, g 1 (j,i)=0. In step S 2 , of the basic pixel group of the current basic frame, the darkest pixel (i.e., pixel having the lowest brightness) at that time is determined as on-pixel. Based on the above equation (1), the values of g 2 (j,i) (0≦i≦3, 0≦j≦3) of all basic pixels included in the current basic pixel group are calculated. The darkest pixel (Jmin, Imin) of the basic pixels is determined. In step S 3 , the pixel (Jmin, Imin) determined in the above step S 2 is set to on state. Then, g 1 (Jmin, Imin)next is set using the following equation based on the above equation (2). g 1 ( Jmin,Imin )next= g 1 ( Jmin,Imin )+ Kr*Ps ( Jmin,Imin ) In step S 4 , it is determined whether or not the procedures of steps S 2 and S 3 are carried out at the predetermined number of times (seven time). In other words, a decision is made whether or not all of seven on-pixels are determined in the currently selected basic pixel group. If a decision is made that all on-pixels are not determined, the process sequence returns to step S 2 , and a pixel to be on next is determined. If a decision is made that all on-pixels are determined, the operation sequence proceeds to step S 5 . In step S 5 , the pattern of the determined seven on-pixels is determined as a temporary display pattern. In step S 6 , the next basic frame is set. That is, g 1 (j,i)next values are determined with respect to all basic pixels included in the basic pixel group using the following equation based on the above equation (2). g 1 ( j,i )next= g 1 ( j,i )*(1 −Kr ) In step S 7 , it is determined whether or not the determined temporary display patterns of all basic frames (16 frames) are stable. More specifically, the finally determined display pattern is compared with the display pattern determined before it (before 16 frame) in each basic frame. If an error based on the comparative result is less than a predetermined value, the display patterns (temporary display patterns) are regarded as being stable in all of 16 frames. On the other hand, if it is determined in step S 7 that the display patterns are not stable, the operation sequence returns to step S 2 , and the operation of the next frame is carried out. In step S 7 , if it is determined that the display patterns are stable, the operation sequence proceeds to step S 8 . In step S 8 , the determined temporary display patterns of 16 frames are determined as the final display patterns. The final display patterns thus determined are stored in the memory section of the liquid crystal display control device. The above operation will be described with reference to FIG. 4 . In each of 0 to 15th frames, display pattern (that seven pixels are on state) is temporarily determined. Thereafter, the operation to the next 0 to 15th frames is carried out. That is, considering the influence of display patterns temporarily determined so far, each display pattern of the 0 to 15th frames is successively updated. The updated display pattern is successively determined as a temporary display pattern. Therefore, when the temporary display pattern is determined in each frame, display patterns (that seven pixels are on state) are obtained in all of 0 to 15th frames. In other words, every when the temporary display pattern is determined in each frame, the decision of step S 7 is made. As described above, according to the second embodiment, the optimal display pattern is determined using the principle of determining the darkest pixel (having the lowest brightness) at that time, and making (lighting) the pixel on state. When gradation display is performed in a state that on pixels and off pixels are dispersed in time and space, human's eye recognize preferable image on its characteristics when on pixels are further dispersed. The method of the second embodiment is employed, and thereby, the on pixels can be effectively dispersed in time and space, and the optimized display pattern can be obtained. In addition, in the second embodiment, the operation is repeated until the display pattern of each frame stabilizes; therefore, the display pattern can be very accurately determined. The second embodiment has described the case of determining the display pattern of the seventh gradation level when the total gradation level number N is 16. Likewise, the method of the second embodiment is applicable to other gradation levels. The total gradation level number N is not limited to 16, and the method of the second embodiment is applicable to various total gradation level numbers described in the first embodiment. Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Disclosed is a liquid crystal display control device for making gradation display on a liquid crystal display panel using binary display patterns, comprising a memory section storing a plurality of pattern data items for a plurality of gradation levels, each of the pattern data items defining a plurality of binary display patterns set for a plurality of basic frames, and each of the binary display patterns being defined by a plurality of basic pixels, and a selector section selecting one of the pattern data items, which corresponds to a designated gradation level, wherein the number of the basic frames and the number of the basic pixels for each of the gradation levels are predetermined and depend on each of the gradation levels.

TECHNICAL FIELD [0001] The present invention relates to a patch that ensures high storage stability of donepezil or a salt thereof and allows stable transdermal administration of the donepezil or salt thereof. BACKGROUND ART [0002] Recently, as the number of elderly persons increases, the number of Alzheimer's dementia patients is increasing, and this has become a social problem. As therapeutic agents for Alzheimer's disease, anticholinesterases such as donepezil hydrochloride have been developed and have been prescribed to the patients as internal medicines such as tablets. [0003] However, as dementia progresses, the patient shows poor compliance, or swallowing dysfunction occurs. In such cases, it is often difficult to get the patient to take a therapeutic agent as directed by a physician. To solve this problem, there is a need for stable transdermal administration of the therapeutic agent. [0004] Meanwhile, the transdermal permeability of a drug such as donepezil or a salt thereof is low, and therefore it is considered to be difficult to allow the drug to be absorbed through the skin in an amount that provides the desired pharmaceutical effect. To solve such a problem, various studies have been conducted, and the following transdermal absorption preparations containing donepezil or a salt thereof have been proposed. [0005] Patent Literature 1 discloses a patch in which a combination of donepezil, a surfactant, and an acrylic adhesive is used to improve the transdermal permeability of donepezil. However, there is no description about the storage stability of donepezil. [0006] Patent Literature 2 discloses suppression of discoloration of a donepezil-containing patch during storage, the donepezil-containing patch including an adhesive layer that is formed on one side of a substrate and contains donepezil and an acrylic adhesive with a specific water content. However, there is no description about the storage stability of donepezil. [0007] Patent Literature 3 discloses a transdermal absorption preparation in which an acrylic adhesive layer containing donepezil and a metal chloride is cross-linked by a cross-linking agent to improve cohesion during removal by peeling. However, there is no description about the storage stability of donepezil. [0008] Patent Literature 4 discloses a transdermal absorption-type dementia therapeutic preparation containing an adhesive composition, wherein the adhesive composition contains one or two or more kinds selected from the group consisting of donepezil and pharmaceutically acceptable salts thereof, and one or two or more kinds selected from the group consisting of organic acids and pharmaceutically acceptable salts thereof. However, there is no description about the storage stability of donepezil. [0009] Patent Literature 5 discloses a patch having an adhesive layer on one side of a substrate, wherein the adhesive layer of the patch contains a fatty acid amide and boric acid. There is a description that the addition of the fatty acid amide and boric acid to the adhesive layer improves the transdermal permeability of donepezil and also improves the storage stability of donepezil. However, the storage stability of donepezil crystals is evaluated only after storage at 25° C. for one month, and there is no description about the storage stability of the donepezil crystals at high temperatures that pharmaceuticals may temporarily experience during distribution thereof. When the patch is stored at high temperatures, the donepezil crystals may dissolve in the adhesive layer. Then when donepezil re-precipitates on the surface of the adhesive layer, the precipitation state of the donepezil crystals may become non-uniform, resulting in non-uniformity of the transdermal permeability of donepezil. CITATION LIST Patent Literature [0000] Patent Literature 1: WO2010/039381 Patent Literature 2: WO2009/145177 Patent Literature 3: WO2008/066179 Patent Literature 4: Japanese Patent No. 4394443 Patent Literature 5: Japanese Patent Application Laid-Open No. 2007-217328 SUMMARY OF INVENTION Technical Problem [0015] The present invention provides a patch that ensures high storage stability of donepezil or a salt thereof and allows stable transdermal administration of the donepezil or salt thereof in an amount that provides a pharmaceutical effect. Solution to Problem [0016] The patch of the present invention comprises a substrate 1 and an adhesive layer 2 stacked on one side of the substrate 1 and integrated therewith, and is characterized in that the adhesive layer 2 contains donepezil or a salt thereof and an acrylic adhesive containing a copolymer obtained by copolymerizing monomers that each contain a (meth)acrylic acid ester of a saturated aliphatic alcohol and do not contain vinylpyrrolidone. Note that the (meth)acrylic acid means methacrylic acid or acrylic acid. [0017] The adhesive layer 2 constituting the above-described patch contains donepezil or a salt thereof. Donepezil ( 2 -[(1-benzyl-4-piperidinyl)methyl]-5,6-dimethoxyindan-1-one) or a salt thereof has an acetylcholinesterase inhibitory action and is used as an anti-Alzheimer's dementia drug. [0018] Examples of the salt of donepezil may include: inorganic acid salts such as hydrochloride, sulfate, nitrate, hydrobromide, and phosphate; and organic acid salts such as acetate, trifluoroacetate, fumarate, maleate, lactate, tartrate, citrate, succinate, malonate, methanesulfonate, and p-toluenesulfonate. Of these, hydrochloride is preferred. [0019] If the total amount of donepezil or a salt thereof contained in the adhesive layer 2 is low, a sufficient amount of the donepezil or salt thereof may not be released from the adhesive layer. If the total amount thereof is high, a large amount of crystals of the donepezil or salt thereof may precipitate on the surface of the adhesive layer, and this may cause the adhesion and flexibility of the adhesive layer to be reduced. In such a case, for example, the patch may peel off the skin during use, and stable transdermal administration of the donepezil or salt thereof may not be achieved. Therefore, the total amount of the donepezil or salt thereof is preferably 1 to 40% by weight, more preferably 5 to 35% by weight, and particularly preferably 10 to 30% by weight. [0020] As described later, a reservoir layer 3 may intervene between the substrate 1 and the adhesive layer 2 . In such a case, if the total amount of donepezil or a salt thereof contained in the adhesive layer 2 is low, a sufficient amount of the donepezil or salt thereof may not be released from the adhesive layer at the initial stage of administration. If the total amount thereof is high, a large amount of crystals of the donepezil or salt thereof may precipitate on the surface of the adhesive layer, and this may cause the adhesion and flexibility of the adhesive layer to be reduced. In such a case, for example, the patch may peel off the skin during use, and stable transdermal administration of the donepezil or salt thereof may not be achieved. Therefore, the total amount of the donepezil or salt thereof is preferably 0.5 to 30% by weight, more preferably 0.5 to 20% by weight, particularly preferably 1 to 15% by weight, and most preferably 1 to 5% by weight. [0021] The above-described adhesive layer 2 contains the acrylic adhesive containing a copolymer obtained by copolymerizing monomers that each contain a (meth)acrylic acid ester of a saturated aliphatic alcohol and do not contain vinylpyrrolidone. [0022] The copolymer contained in the acrylic adhesive is obtained by copolymerizing monomers that each contain a (meth)acrylic acid ester of a saturated aliphatic alcohol and do not contain vinylpyrrolidone. Note that the copolymer may be used alone, or two or more kinds of copolymers may be used in combination. [0023] Examples of the saturated aliphatic alcohols may include monohydric saturated aliphatic alcohols (R 1 —OH), dihydric saturated aliphatic alcohols, and trihydric saturated aliphatic alcohols. Of these, monohydric saturated aliphatic alcohols are preferred. A monohydric saturated aliphatic alcohol is obtained by substituting one hydrogen atom in an alkane with a hydroxyl group (—OH). A dihydric saturated aliphatic alcohol is obtained by substituting two hydrogen atoms in an alkane with hydroxyl groups (—OH). A trihydric saturated aliphatic alcohol is obtained by substituting three hydrogen atoms in an alkane with hydroxyl groups (—OH). Note that R 1 is an alkyl group. [0024] The type of monohydric saturated aliphatic alcohol represented by R 1 —OH to be used is not particularly limited, and examples thereof may include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, hexyl alcohol, n-octyl alcohol, isooctyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl alcohol, and hexadecyl alcohol. [0025] The type of dihydric saturated aliphatic alcohol to be used is not particularly limited, and examples thereof may include hydroxy ethyl alcohol and hydroxy propyl alcohol. [0026] Examples of the trihydric saturated aliphatic alcohol may include glycerin. [0027] In the monohydric saturated aliphatic alcohol represented by R 1 —OH, if the number of carbon atoms in R 1 is small, the elasticity of the acrylic adhesive may become low, and the adhesion required for the patch may not be obtained. If the number of carbon atoms in R 1 is large, a liquid additive added to the acrylic adhesive to control its adhesion may exude from the adhesive layer over time, and the transdermal permeability and storage stability of donepezil or a salt thereof may change. Therefore, the number of carbon atoms in R 1 is preferably 2 to 16 and more preferably 3 to 16. [0028] The (meth)acrylic acid ester of the saturated aliphatic alcohol is preferably a (meth)acrylic acid ester of a monohydric saturated aliphatic alcohol represented by R 1 —OH. Examples of the (meth)acrylic acid ester of the saturated aliphatic alcohol may include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, hexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethyhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, hexadecyl (meth)acrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate. Of these, dodecyl (meth)acrylate and 2-ethylhexyl (meth)acrylate are preferred, and a combination of dodecyl (meth)acrylate and 2-ethylhexyl (meth)acrylate is more preferred. These (meth)acrylic acid esters of the saturated aliphatic alcohols may be used alone or two or more kinds of these may be used in combination. In the present invention, (meth)acrylate means methacrylate or acrylate. [0029] The copolymer constituting the acrylic adhesive contains, as monomer components, at least two kinds of (meth)acrylic acid esters of saturated aliphatic alcohols. If the copolymer constituting the acrylic adhesive has pyrrolidone groups, the storage stability of donepezil or a salt thereof decreases. Therefore, the copolymer contains no vinylpyrrolidone as a monomer component. [0030] The adhesion of the patch and its ability to dissolve and release donepezil or a salt thereof can be controlled by adjusting the kinds of (meth)acrylic acid esters of saturated aliphatic alcohols being the monomer components in the acrylic adhesive and the ratio of copolymerization. Therefore, the acrylic adhesive is suitable as an adhesive for supporting donepezil or a salt thereof. [0031] The acrylic adhesive may further contain, as a monomer component, an additional monomer excepting vinylpyrrolidone. The addition of the additional monomer is preferred because the adhesion of the patch and its ability to dissolve and release donepezil or a salt thereof can be controlled with higher accuracy. [0032] Examples of the additional monomer excepting vinylpyrrolidone may include itaconic acid, maleic acid, maleic anhydride, acrylamide, dimethylacrylamide, acrylonitrile, dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, vinyl acetate, and vinyl propionate. [0033] The acrylic adhesive may further contain a cross-linking agent as a monomer component. Examples of such a cross-linking agent may include polyisocyanate compounds, metal chelate compounds, metal alkoxide compounds, and epoxy compounds other than the above-described polyfunctional monomers. When the cross-linking agent is added as a monomer component of the acrylic adhesive, the internal cohesion of the acrylic adhesive is improved, and therefore the adhesive is less likely to remain on the skin when the patch is removed from the skin. [0034] Any well-known method may be used as a polymerization method for producing the acrylic adhesive. Examples of the polymerization method may include a method in which the above-described monomers are mixed in the presence of a polymerization initiator to perform solution polymerization. More specifically, prescribed amounts of monomers, a polymerization initiator, and an optionally added cross-linking agent, together with a polymerization solvent, are supplied to a reaction vessel equipped with a stirrer and a reflux condenser for the vaporized solvent. Then, the mixture is heated at temperatures of 60 to 80° C. for 4 to 48 hours to subject the monomers to a radical polymerization reaction. [0035] Examples of the polymerization initiator may include: azobis-based polymerization initiators such as 2,2′-azobisisobutyronitrile (AIBN), 1,1′-azobis(cyclohexane-1-carbonitrile), and 2,2′-azobis-(2,4′-dimethylvaleronitrile); and peroxide-based polymerization initiators such as benzoyl peroxide (BPO), lauroyl peroxide (LPO), and di-tert-butyl peroxide. Examples of the polymerization solvent may include ethyl acetate and toluene. Preferably, the polymerization reaction is performed in a nitrogen gas atmosphere. [0036] If the amount of the acrylic adhesive contained in the adhesive layer 2 is low, the cohesion of the adhesive layer becomes insufficient, and this may, for example, cause a problem in that the adhesive layer remains on the skin when the patch is removed from the skin. If the amount thereof is high, the adhesive layer may not be capable of containing donepezil or a salt thereof in an amount sufficient to obtain sufficient releasability of the donepezil or salt thereof from the adhesive layer. Therefore, the amount of the acrylic adhesive is preferably 40 to 99% by weight, more preferably 50 to 95% by weight, and particularly preferably 60 to 90% by weight. [0037] As described later, a reservoir layer 3 may intervene between the substrate 1 and the adhesive layer 2 . In such a case, if the total amount of the acrylic adhesive contained in the adhesive layer 2 is low, the cohesion of the adhesive layer becomes low, and this may cause a problem in that the adhesive layer remains on the skin when the patch is removed from the skin. If the total amount is high, the adhesive layer may not be capable of containing donepezil or a salt thereof in an amount sufficient to obtain sufficient releasability of the donepezil or salt thereof from the adhesive layer at the initial stage of administration. Therefore, the total amount of the acrylic adhesive is preferably 60 to 99.5% by weight, more preferably 70 to 99% by weight, and particularly preferably 75 to 98.5% by weight. [0038] The adhesive layer 2 may further contain a resolvent for the purpose of improving the amount of donepezil or a salt thereof dissolved in the adhesive layer 2 . Preferably, the adhesive layer 2 contains, as such a resolvent, at least one compound selected from the group consisting of esters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols, saturated aliphatic alcohols, and saturated aliphatic carboxylic acids, because the transdermal permeability of donepezil or a salt thereof can be improved. By further improving the amount of the donepezil or salt thereof dissolved in the acrylic adhesive and improving the diffusibility of the donepezil or salt thereof in the acrylic adhesive, the excess of the donepezil or salt thereof that remains undissolved in the adhesive layer during production thereof can be rapidly precipitated on the surface of the adhesive layer. Therefore, more preferably, the adhesive layer 2 contains at least one compound selected from the group consisting of diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols. [0039] If the total amount of the at least one compound selected from the group consisting of esters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols, saturated aliphatic alcohols, and saturated aliphatic carboxylic acids contained in the adhesive layer 2 is low, the rate of precipitation of crystals of the excess of the donepezil or salt thereof that remains undissolved in the adhesive layer during production of the patch may become unacceptably low, and the precipitation state of the crystals of the donepezil or salt thereof on the surface of the adhesive layer may become non-uniform. If the total amount thereof is high, the resolvent may exude from the adhesive layer over time. Therefore, the total amount thereof is preferably 5 to 35% by weight and more preferably 10 to 30% by weight. [0040] First, the esters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols will be described. Examples of the esters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols may include monoesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols, diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols, and triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols. [0041] The saturated aliphatic alcohols are preferably monohydric saturated aliphatic alcohols (R 2 —OH), dihydric saturated aliphatic alcohols, and trihydric saturated aliphatic alcohols. A monohydric saturated aliphatic alcohol is obtained by substituting one hydrogen atom in an alkane with a hydroxyl group (—OH). A dihydric saturated aliphatic alcohol is obtained by substituting two hydrogen atoms in an alkane with hydroxyl groups (—OH). A trihydric saturated aliphatic alcohol is obtained by substituting three hydrogen atoms in an alkane with hydroxyl groups (—OH). Note that R 2 is an alkyl group. [0042] In the monohydric saturated aliphatic alcohol represented by R 2 —OH, if the number of carbon atoms in R 2 is large, the compatibility between the acrylic adhesive and an ester of a saturated aliphatic carboxylic acid with a saturated aliphatic alcohol may become low. In such a case, the ester of the saturated aliphatic carboxylic acid with the saturated aliphatic alcohol may exude from the surface of the adhesive layer during production of the patch, and this may cause a reduction in the adhesion of the adhesive layer. Therefore, the number of carbon atoms in R 2 is preferably 1 to 22 and further preferably 1 to 18. [0043] The type of monohydric saturated aliphatic alcohol to be used is not particularly limited, and examples thereof may include methyl alcohol, ethyl alcohol, n-butyl alcohol, n-propyl alcohol, isopropyl alcohol, hexyl alcohol, n-octyl alcohol, isooctyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol (myristyl alcohol), hexadecyl alcohol, isostearyl alcohol, hexyldecanol, and octyldodecanol. [0044] The type of dihydric saturated aliphatic alcohol to be used is not particularly limited, and examples thereof may include hydroxy ethyl alcohol and hydroxy propyl alcohol. [0045] Examples of the trihydric saturated aliphatic alcohol may include glycerin. [0046] The saturated aliphatic carboxylic acid is preferably any of saturated aliphatic monocarboxylic acids, saturated aliphatic dicarboxylic acids, and saturated aliphatic tricarboxylic acids. [0047] A saturated aliphatic monocarboxylic acid is a carboxylic acid (R 3 —COOH) obtained by substituting one hydrogen atom in an alkane with a carboxy group (—COOH). Note that R 3 is an alkyl group or a substituent in which one or two or more hydrogen atoms in an alkyl group are substituted with hydroxyl groups. The type of saturated aliphatic monocarboxylic acid to be used is not particularly limited, and examples thereof may include myristic acid, isostearic acid, and lauric acid. [0048] In the carboxylic acid represented by R 3 —COOH, if the number of carbon atoms in R 3 is large, the compatibility between the acrylic adhesive and an ester of a saturated aliphatic carboxylic acid with a saturated aliphatic alcohol may become low. In such a case, the ester of the saturated aliphatic carboxylic acid with the saturated aliphatic alcohol may exude from the surface of the adhesive layer during production of the patch, and this may cause a reduction in the adhesion of the adhesive layer. Therefore, the number of carbon atoms in R 3 is preferably 1 to 22 and more preferably 1 to 18. [0049] A saturated aliphatic dicarboxylic acid is a carboxylic acid obtained by substituting two hydrogen atoms in an alkane with carboxy groups (—COOH), and one or two or more hydrogen atoms may be further substituted with hydroxyl groups. The type of saturated aliphatic dicarboxylic acid to be used is not particularly limited, and examples thereof may include sebacic acid and adipic acid. [0050] A saturated aliphatic tricarboxylic acid is a carboxylic acid obtained by substituting three hydrogen atoms in an alkane with carboxy groups (—COOH), and one or two or more hydrogen atoms may be further substituted with hydroxyl groups. The type of saturated aliphatic tricarboxylic acid to be used is not particularly limited, and examples thereof may include citric acid. [0051] Examples of the monoesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols may include monoesters of saturated aliphatic monocarboxylic acids with monohydric saturated aliphatic alcohols represented by R 2 —OH. Examples of the monoesters of saturated aliphatic monocarboxylic acids with monohydric saturated aliphatic alcohols represented by R 2 —OH may include isopropyl myristate and hexyl laurate. [0052] Examples of the diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols may include: diesters of saturated aliphatic dicarboxylic acids with monohydric saturated aliphatic alcohols represented by R 2 —OH; and diesters of saturated aliphatic monocarboxylic acids with dihydric saturated aliphatic alcohols obtained by substituting two hydrogen atoms in an alkane with hydroxyl groups (—OH). Of these, diesters of saturated aliphatic dicarboxylic acids with monohydric saturated aliphatic alcohols represented by R 2 —OH are preferred. Examples of the diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols may include diethyl sebacate, diisopropyl sebacate, and diisopropyl adipate. [0053] Examples of the triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols may include: triesters of saturated aliphatic tricarboxylic acids with monohydric saturated aliphatic alcohols represented by R 2 —OH; and triesters of saturated aliphatic monocarboxylic acids with trihydric saturated aliphatic alcohols obtained by substituting three hydrogen atoms in an alkane with hydroxyl groups (—OH). Of these, triesters of saturated aliphatic tricarboxylic acids with monohydric saturated aliphatic alcohols represented by R 2 —OH are preferred. Examples of the triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols may include triethyl citrate and triacetin. [0054] The saturated aliphatic alcohol used as the resolvent is preferably any of monohydric saturated aliphatic alcohols (R 4 —OH), dihydric saturated aliphatic alcohols, and trihydric saturated aliphatic alcohols. A monohydric saturated aliphatic alcohol is obtained by substituting one hydrogen atom in an alkane with a hydroxyl group (—OH). A dihydric saturated aliphatic alcohol is obtained by substituting two hydrogen atoms in an alkane with hydroxyl groups (—OH). A trihydric saturated aliphatic alcohol is obtained by substituting three hydrogen atoms in an alkane with hydroxyl groups (—OH). Note that R 4 is an alkyl group. [0055] In the monohydric saturated aliphatic alcohol represented by R 4 —OH, if the number of carbon atoms in R 4 is large, the compatibility between the monohydric saturated aliphatic alcohol and the acrylic adhesive may become low. In such a case, the monohydric saturated aliphatic alcohol may exude from the surface of the adhesive layer, and this may cause a reduction in the adhesion of the adhesive layer. Therefore, the number of carbon atoms in R 4 is preferably 1 to 22 and more preferably 1 to 20. [0056] The type of monohydric saturated aliphatic alcohol to be used is not particularly limited, and examples thereof may include methyl alcohol, ethyl alcohol, n-butyl alcohol, n-propyl alcohol, isopropyl alcohol, hexyl alcohol, n-octyl alcohol, isooctyl alcohol, 2-ethylhexyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol (myristyl alcohol), hexadecyl alcohol, isostearyl alcohol, hexyldecanol, octyldodecanol, and docosanol. Of these, octyldodecanol (octyldodecan-1-ol) is preferred. Of these, 2-octyldodecanol (2-octyldodecan-1-ol) is more preferred. [0057] The type of dihydric saturated aliphatic alcohol to be used is not particularly limited, and examples thereof may include hydroxy ethyl alcohol and hydroxy propyl alcohol. [0058] Examples of the trihydric saturated aliphatic alcohol may include glycerin. [0059] The saturated aliphatic carboxylic acid used as the resolvent is preferably any of saturated aliphatic monocarboxylic acids, saturated aliphatic dicarboxylic acids, and saturated aliphatic tricarboxylic acids. [0060] A saturated aliphatic monocarboxylic acid is a carboxylic acid (R 5 —COOH) obtained by substituting one hydrogen atom in an alkane with a carboxy group (—COOH). Note that R 5 is an alkyl group or a substituent in which one or two or more hydrogen atoms in an alkyl group are substituted with hydroxyl groups. The type of saturated aliphatic monocarboxylic acid to be used is not particularly limited, and examples thereof may include myristic acid, isostearic acid, and lauric acid. [0061] In the carboxylic acid represented by R 5 —COOH, if the number of carbon atoms in R 5 is large, the compatibility between the carboxylic acid and the acrylic adhesive may become low. In such a case, the carboxylic acid may exude from the surface of the adhesive layer, and this may cause a reduction in the adhesion of the adhesive layer. Therefore, the number of carbon atoms in R 5 is preferably 1 to 22 and more preferably 1 to 18. [0062] A saturated aliphatic dicarboxylic acid is a carboxylic acid obtained by substituting two hydrogen atoms in an alkane with carboxy groups (—COOH), and one or two or more hydrogen atoms may be further substituted with hydroxyl groups. The type of saturated aliphatic dicarboxylic acid to be used is not particularly limited, and examples thereof may include sebacic acid and adipic acid. [0063] A saturated aliphatic tricarboxylic acid is a carboxylic acid obtained by substituting three hydrogen atoms in an alkane with carboxy groups (—COOH), and one or two or more hydrogen atoms may be further substituted with hydroxyl groups. The type of saturated aliphatic tricarboxylic acid to be used is not particularly limited, and examples thereof may include citric acid. [0064] Preferably, the adhesive layer 2 contains, as resolvents, at least one compound selected from the group consisting of diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and at least one compound selected from the group consisting of monoesters of saturated aliphatic monocarboxylic acids with monohydric saturated aliphatic alcohols and monohydric saturated aliphatic alcohols. [0065] The diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and the triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols are the same as those described above, and descriptions thereof will be omitted. The monoesters of saturated aliphatic monocarboxylic acids with monohydric saturated aliphatic alcohols are the same as those described above, and a description thereof will be omitted. The monohydric saturated aliphatic alcohols are the same as the monohydric saturated aliphatic alcohol represented by R 4 —OH, and a description thereof will be omitted. [0066] The solubility of donepezil or a salt thereof in the diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and the triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols is greatly affected by temperature. When the patch is stored at high temperatures, part of crystals of the donepezil or salt thereof that are precipitated on the surface of the adhesive layer may dissolve in a diester of a saturated aliphatic carboxylic acid with a saturated aliphatic alcohol or a triester of a saturated aliphatic carboxylic acid with a saturated aliphatic alcohol, and therefore the state of precipitation of the donepezil or salt thereof on the surface of the adhesive layer may become non-uniform. This may cause non-uniformity of the transdermal permeability of the donepezil or salt thereof from the adhesive layer. [0067] Therefore, at least one compound selected from the group consisting of monoesters of saturated aliphatic monocarboxylic acids with monohydric saturated aliphatic alcohols and monohydric saturated aliphatic alcohols, in which the solubility of donepezil or a salt thereof is not greatly affected by temperature, is combined with at least one compound selected from the group consisting of diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols. Such a combination can prevent non-uniformity of the state of precipitation of the donepezil or salt thereof on the surface of the adhesive layer even when the patch is stored at high temperatures. [0068] In addition, the combination of at least one compound selected from the group consisting of diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols with at least one compound selected from the group consisting of monohydric saturated aliphatic alcohols and monoesters of saturated aliphatic monocarboxylic acids with monohydric saturated aliphatic alcohols allows the amount of donepezil or a salt thereof dissolved in the adhesive layer and the diffusibility of the donepezil or salt thereof in the adhesive layer to be appropriately controlled. The transdermal permeability of the donepezil or salt thereof can thereby be improved. [0069] If the total amount of the at least one compound selected from the group consisting of diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols contained in the adhesive layer 2 is low, the rate of precipitation of crystals of the excess of donepezil or a salt thereof that remains undissolved in the adhesive layer during production of the patch may become unacceptably low, and the precipitation state of the crystals of the donepezil or salt thereof on the surface of the adhesive layer may become non-uniform. If the total amount thereof is high, the resolvent may exude from the adhesive layer over time, or the donepezil or salt thereof precipitated on the surface of the adhesive layer may dissolve in the resolvent when the patch is stored at high temperatures, so that, when crystals of the donepezil or salt thereof re-precipitate on the surface of the adhesive layer, the precipitation state of the crystals of the donepezil or salt thereof may become non-uniform. Therefore, the total amount thereof is preferably 5 to 25% by weight and more preferably 10 to 15% by weight. [0070] If the total amount of the at least one compound selected from the group consisting of monoesters of saturated aliphatic monocarboxylic acids with monohydric saturated aliphatic alcohols and monohydric saturated aliphatic alcohols contained in the adhesive layer 2 is low, the rate of precipitation of crystals of the excess of donepezil or a salt thereof that remains undissolved in the adhesive layer during production of the patch may become unacceptably low, so that the precipitation state of the crystals of the donepezil or salt thereof may become non-uniform. Also, if the total amount thereof is low, the influence of temperature changes on the solubility of the donepezil or salt thereof in the adhesive layer may not be suppressed because of the at least one compound selected from the group consisting of diesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols and triesters of saturated aliphatic carboxylic acids with saturated aliphatic alcohols. If the total amount thereof is high, the resolvent may exude from the adhesive layer over time. Therefore the total amount thereof is preferably 3 to 30% by weight and more preferably 5 to 20% by weight. [0071] The adhesive layer 2 may further contain a general-purpose resolvent such as liquid paraffin in addition to the above-described resolvents. [0072] If the total amount of the resolvents contained in the adhesive layer 2 is low, the rate of precipitation of crystals of the excess of donepezil or a salt thereof that remains undissolved in the adhesive layer during production of the patch may become unacceptably low, and the precipitation state of the crystals of the donepezil or salt thereof on the surface of the adhesive layer may become non-uniform. If the total amount thereof is high, the cohesion of the adhesive layer may decrease, and this may, for example, cause a problem in that the adhesive layer remains on the skin when the patch is removed from the skin. Therefore, the total amount thereof is preferably 5 to 35% by weight and more preferably 10 to 30% by weight. [0073] Note that the adhesive layer 2 may further contain additives such as a stabilizer and a filler, so long as the physical properties of the adhesive layer 2 are not impaired. However, preferably, the adhesive layer 2 contains no cellulose described later. [0074] The stabilizer is added for the purpose of suppressing the oxidation and decomposition of donepezil or a salt thereof. Examples of the stabilizer may include antioxidants such as butylhydroxytoluene and tocopherol acetate, cyclodextrin, and ethylenediaminetetraacetic acid. Preferably, the stabilizer is contained in the adhesive layer 2 in an amount of 0.05 to 10% by weight. [0075] The filler is added in order to control the adhesion of the patch and the transdermal absorbability of donepezil or a salt thereof. Examples of such a filler may include: inorganic fillers such as silicic acid anhydride, titanium oxide, and zinc oxide; organic metal salts such as calcium carbonate and magnesium stearate; lactose; cellulose derivatives such as crystalline cellulose, ethyl cellulose, and low substituted hydroxypropyl cellulose; polyacrylic acid; and polymethacrylic acid. Preferably, the filler is contained in the adhesive layer 2 in an amount of 1 to 15% by weight. [0076] The patch may not include the reservoir layer described later. In such a case, if the thickness of the adhesive layer 2 is small, the adhesive layer may not be capable of containing donepezil or a salt thereof in an amount necessary to obtain the desired blood level of the drug. If the thickness is large, the adhesive layer may bulge out of the substrate during storage or use of the patch, and the adhesive feeling of the patch may deteriorate. Also, the time required to remove the solvent during the production of the adhesive layer may increase, and this causes a reduction in the production efficiency of the patch. Therefore, the thickness of the adhesive layer 2 is preferably 10 to 500 μm, more preferably 50 to 200 μm, and particularly preferably 80 to 150 μm. [0077] The substrate 1 constituting the patch of the present invention is stacked on and integrated with the adhesive layer 2 . The substrate 1 prevents loss of the drug in the adhesive layer 2 and protects the adhesive layer 2 . In addition, the substrate 1 is required to have strength sufficient to provide self-supportability to the patch and also have flexibility sufficient to provide good adhesive feeling to the patch. [0078] The type of such substrate 1 to be used is not particularly limited, and examples thereof may include a resin sheet, a foamed resin sheet, a nonwoven fabric, a woven fabric, a knitted fabric, and an aluminum sheet. The substrate 1 may be composed of a single layer or a plurality of stacked and integrated layers. [0079] Examples of the resin forming the above resin sheet may include cellulose acetate, ethyl cellulose, rayon, polyethylene terephthalate, plasticized vinyl acetate-vinyl chloride copolymers, nylon, ethylene-vinyl acetate copolymers, plasticized polyvinyl chloride, polyurethane, polyethylene, polypropylene, and polyvinylidene chloride. Of these, polyethylene terephthalate is preferred. [0080] Preferably, the substrate 1 is prepared by stacking and integrating a polyethylene terephthalate sheet and a nonwoven fabric or a soft resin sheet, from the viewpoint of the flexibility of the substrate and the effect of preventing loss of donepezil or a salt thereof. A substrate prepared by stacking and integrating a polyethylene terephthalate sheet and a nonwoven fabric is more preferred. Examples of the material forming the nonwoven fabric may include polyethylene, polypropylene, ethylene-vinyl acetate copolymers, ethylene-methyl (meth)acrylate copolymers, nylon, polyester, vinylon, SIS copolymers, SEBS copolymers, rayon, and cotton. Of these, polyester is preferred. Note that these materials may be used alone, or two or more kinds thereof may be used in combination. [0081] Preferably, for the purpose of preventing loss of the drug in the adhesive layer 2 of the patch of the present invention and protecting the adhesive layer 2 , release paper 5 is releasably stacked on and integrated with the surface of the adhesive layer 2 of the patch. [0082] Examples of the release paper 5 may include paper and resin films formed of polyethylene terephthalate, polyethylene, polypropylene, polyvinyl chloride, or polyvinylidene chloride. Preferably, the surface of the release paper 5 that faces the adhesive layer 2 has been subjected to release treatment. Note that the above release paper 5 may be composed of a single layer or a plurality of layers. [0083] For the purpose of improving the barrier properties of the release paper, aluminum foil or an aluminum layer formed by vapor deposition may be provided to the release paper. When the release paper is formed of paper, the release paper may be impregnated with a resin such as polyvinyl alcohol, for the purpose of improving the barrier properties of the release paper. [0084] As shown in FIG. 2 , a reservoir layer 3 may intervene between the substrate 1 and the adhesive layer 2 in order to improve the sustained release of donepezil or a salt thereof from the patch. The reservoir layer 3 contains cellulose and donepezil or a salt thereof. The type of cellulose contained in the reservoir layer 3 to be used is not particularly limited, and examples thereof may include hydroxypropyl cellulose, hypromellose, and ethyl cellulose. Of these, ethyl cellulose is preferred. For example, the cellulose used may be commercially available cellulose for use as a pharmaceutical additive. Examples of the commercially available cellulose for use as a pharmaceutical additive may include NISSO HPC (hydroxypropyl cellulose, manufactured by Nippon Soda Co., Ltd.), TC-5 and SB-4 (hypromellose, manufactured by Shin-Etsu Chemical Co., Ltd.), and ETHOCEL (registered trademark) (ethyl cellulose, manufactured by The Dow Chemical Company). [0085] The viscosity of the cellulose is preferably 3 to 300 cps and more preferably 7 to 200 cps. If the viscosity of the cellulose is low, the flexibility of the reservoir layer becomes low, and cracks etc. occur during production. Therefore, donepezil or a salt thereof may not be uniformly contained over the reservoir layer, or the rate of release of the donepezil or salt thereof may become excessively high. If the viscosity of the cellulose is high, the diffusibility of the donepezil or salt thereof in the reservoir layer may be reduced significantly, and the rate of release of the donepezil or salt thereof from the patch may become low. By controlling the viscosity of the cellulose, the desired sustained release of the donepezil or salt thereof can be obtained. Note that the viscosity of the cellulose can be measured by a routine method using a B-type viscometer. [0086] If the amount of the cellulose contained in the reservoir layer 3 is low, the thickness of the reservoir layer may become non-uniform. If the amount thereof is high, the reservoir layer may not be capable of containing donepezil or a salt in an amount sufficient to release the donepezil or salt thereof from the patch for several days. Therefore, the amount of the cellulose is preferably 15 to 70% by weight and more preferably 30 to 50% by weight. [0087] If the total amount of donepezil or a salt thereof contained in the reservoir layer 3 is low, it may not be possible to release a sufficient amount of the donepezil or salt thereof from the adhesive layer for several days. If the total amount thereof is high, the amount of crystals of the donepezil or salt thereof precipitated on the surface of the reservoir layer that faces the adhesive layer may become high, and the conformity between the adhesive layer and the reservoir layer may deteriorate. In such a case, the reservoir layer may peel off the skin during the use of the patch, so that stable transdermal administration of the donepezil or salt thereof may not be achieved. Therefore, the total amount thereof is preferably 20 to 60% by weight and more preferably 30 to 50% by weight. [0088] Note that the reservoir layer 3 may contain the above-described acrylic adhesive, the above-described resolvent, the above-described stabilizer, and the above-described filler, so long as the physical properties of the reservoir layer 3 are not impaired. [0089] The above-described resolvent not only improves the solubility of donepezil or a salt thereof in the reservoir layer but also facilitates the precipitation of crystals of the donepezil or salt thereof on the surface of the reservoir layer that faces the adhesive layer. When the donepezil or salt thereof precipitates on the surface of the reservoir layer that faces the adhesive layer, the concentration of the donepezil or salt thereof present near the interface between the reservoir layer and the adhesive layer can be made high, and the supply of the donepezil or salt thereof to the adhesive layer can be facilitated. The resolvent that facilitates the precipitation of the donepezil or salt thereof on the surface of the reservoir layer that faces the adhesive layer is preferably a compound that improves the diffusibility of the donepezil or salt thereof in the cellulose. Examples of such a resolvent may include triacetin, triethyl citrate, diisopropyl adipate, and isopropyl myristate. Of these, triacetin and isopropyl myristate are preferred. [0090] If the thickness of the reservoir layer 3 is small, the reservoir layer may not be capable of containing donepezil or a salt in an amount sufficient to release the donepezil or salt thereof from the patch for several days. If the thickness is large, the flexibility of the patch becomes low, and the patch may peel off the skin during use. Therefore, the thickness of the reservoir layer 3 is preferably 5 to 400 μm, more preferably 10 to 300 μm, and particularly preferably 20 to 150 μm. [0091] In the case of the patch including the reservoir layer, if the thickness of the adhesive layer 2 is small, the adhesive layer may not be capable of containing donepezil or a salt thereof in an amount necessary to obtain the desired blood level of the drug at the initial stage of administration. If the thickness is large, the adhesive layer may bulge out of the substrate during storage or use of the patch, and the adhesive feeling of the patch may deteriorate. Also, the time required to remove the solvent during the production of the adhesive layer may increase, and this causes a reduction in the production efficiency of the patch. Therefore, the thickness of the adhesive layer 2 is preferably 10 to 200 μm, more preferably 20 to 150 μm, and particularly preferably 30 to 100 μm. [0092] The adhesive layer 2 may be directly stacked on and integrated with the reservoir layer 3 as shown in FIG. 2 . Alternatively, as shown in FIG. 3 , an intermediate layer 4 such as a synthetic resin film, e.g., a polyolefin-based resin film such as a polyethylene film or a polypropylene film, may be interposed between the reservoir layer 3 and the adhesive layer 2 , in order to control the rate of release of donepezil or a salt thereof from the reservoir layer to the adhesive layer. Preferably, a large number of through holes are formed in the synthetic resin film. The thickness of the intermediate layer 4 is preferably 1 μm or less. [0093] A method of producing the patch of the present invention will next be described. The type of the method of producing the patch to be used is not particularly limited. Examples of the production method may include: (1) a method including adding donepezil or a salt thereof and an acrylic adhesive to a solvent such as ethyl acetate and optionally adding an additive thereto, stirring the mixture uniformly to obtain an adhesive layer solution, applying the obtained adhesive layer solution to one side of a substrate by a commonly used procedure, drying the adhesive layer solution to stack an adhesive layer on the one side of the substrate and integrate the adhesive layer with the substrate, and optionally stacking-integrating release paper on-with the adhesive layer such that the surface of the release paper that has been subjected to release treatment faces the adhesive layer: and (2) a method including applying the adhesive layer solution to the surface of release paper that has been subjected to release treatment by a commonly used coating method, drying the adhesive layer solution to form an adhesive layer on the release paper, and stacking-integrating a substrate on-with the adhesive layer. [0094] When the reservoir layer 3 is interposed between the substrate 1 and the adhesive layer 2 , the patch may be produced as follows. For example, first, the above adhesive layer solution is applied to the surface of release paper that has been subjected to release treatment by a commonly used coating procedure and then dried to form an adhesive layer on the release paper. Then a reservoir layer solution is prepared by adding cellulose, donepezil or a salt thereof, and optionally added additives to a solvent such as ethyl acetate and stirring the mixture until uniform. The reservoir layer solution is applied to the surface of separate release paper that has been subjected to release treatment by a commonly used coating procedure and then dried to form a reservoir layer on the release paper. Then the reservoir layer and the adhesive layer are stacked on and integrated with one surface of a substrate in that order. If necessary, release paper is stacked on and integrated with the adhesive layer such that the surface of the release paper that has been subjected to release treatment faces the adhesive layer, and a patch is thereby produced. When the intermediate layer 4 is interposed between the reservoir layer 3 and the adhesive layer 2 , the reservoir layer 3 , a film serving as the intermediate layer 4 , and the adhesive layer 2 are stacked on and integrated with one surface of a substrate in that order to produce a patch. Advantageous Effects of Invention [0095] The patch of the present invention has the above-described configuration. This ensures high storage stability of donepezil or a salt thereof and allows the donepezil or salt thereof to precipitate on the surface of the adhesive layer uniformly as crystals. Therefore, when the patch of the present invention is applied to the skin, the donepezil or salt thereof dissolved in the adhesive layer is transdermally administered. Then when the amount of the donepezil or salt thereof dissolved in the adhesive layer decreases, the crystals of the donepezil or salt thereof precipitated on the surface of the adhesive layer smoothly dissolve in the entire adhesive layer and are supplied thereto, and the donepezil or salt thereof is transdermally administered from the entire adhesive layer uniformly and stably. BRIEF DESCRIPTION OF DRAWINGS [0096] FIG. 1 is a vertical cross-sectional view showing a patch of the present invention. [0097] FIG. 2 is a vertical cross-sectional view showing another example of the patch of the present invention. [0098] FIG. 3 is a vertical cross-sectional view showing another example of the patch of the present invention. DESCRIPTION OF EMBODIMENTS Preparation of Acrylic Adhesive A [0099] An acrylic adhesive A was prepared as follows. A 40 L polymerization apparatus was charged with a reaction mixture composed of 50 parts by weight of ethyl acetate and monomers including 13 parts by weight of dodecyl methacrylate, 78 parts by weight of 2-ethylhexyl methacrylate, and 9 parts by weight of 2-ethylhexyl acrylate, and the atmosphere in the polymerization apparatus was replaced with a nitrogen atmosphere at 80° C. Then a polymerization initiator solution prepared by dissolving 0.5 parts by weight of benzoyl peroxide in 50 parts by weight of cyclohexane was added to the above reaction mixture over 24 hours to copolymerize the above monomers. After completion of the polymerization, ethyl acetate was further added to the resultant reaction mixture to obtain an acrylic adhesive solution A containing 35% by weight of the acrylic adhesive A. (Adjustment of Acrylic Adhesive B) [0100] A separable flask was charged with a reaction mixture composed of 200 parts by weight of ethyl acetate and monomers including 150 parts by weight of 2-ethylhexyl acrylate and 50 parts by weight of N-vinylpyrrolidone, and the atmosphere in the separable flask was replaced with a nitrogen atmosphere at 80° C. A polymerization initiator solution prepared by dissolving 1 part by weight of benzoyl peroxide in 100 parts by weight of ethyl acetate was added to the reaction mixture over 27 hours to polymerize the above monomers. After completion of the polymerization, ethyl acetate was further added to the resultant reaction mixture to obtain an acrylic adhesive solution B containing 32% by weight of an acrylic adhesive B. Examples 1 to 14 [0101] Donepezil, the acrylic adhesive A, diisopropyl sebacate, diisopropyl adipate, isopropyl myristate, 2-octyldodecanol (2-octyldodecan-1-ol), and liquid paraffin were mixed in compositional weight ratios shown in TABLE 1. Then ethyl acetate was added to the mixtures such that the concentration of solids was 22% by weight, and the resultant mixtures were stirred until uniform to thereby produce adhesive layer solutions. [0102] Next, 38 μm-thick polyethylene terephthalate films subjected to silicone release treatment were prepared, and the above-prepared adhesive layer solutions were applied to the silicone release-treated surfaces of the polyethylene terephthalate films and dried at 60° C. for 30 minutes to thereby produce stacked bodies with adhesive layers with thicknesses shown in TABLE 1 formed on the silicone release-treated surfaces of the polyethylene terephthalate films. [0103] Then 38 μm-thick polyethylene terephthalate films used as substrates were prepared and placed over the above-produced stacked bodies such that one sides of the substrates faced the adhesive layers of the stacked bodies. The adhesive layers of the stacked bodies were transferred to, stacked on, and integrated with the substrates, and patches were thereby produced. [0000] TABLE 1 EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- PLE 1 PLE 2 PLE 3 PLE 4 PLE 5 PLE 6 PLE 7 PLE 8 ADHESIVE DONEPEZIL 4 12 12 12 12 12 12 20 LAYER (% BY WEIGHT) ACRYLIC ADHESIVE 96 88 63 63 63 63 58 60 A (% BY WEIGHT) ACRYLIC ADHESIVE 0 0 0 0 0 0 0 0 B (% BY WEIGHT) DIISOPROPYL 0 0 25 0 15 15 0 0 SEBACATE (% BY WEIGHT) DIISOPROPYL 0 0 0 25 0 0 15 10 ADIPATE (% BY WEIGHT) ISOPROPYL 0 0 0 0 0 10 15 10 MYRISTATE (% BY WEIGHT) 2-OCTYLDODECANOL 0 0 0 0 10 0 0 0 (% BY WEIGHT) LIQUID PARAFFIN 0 0 0 0 0 0 0 0 (% BY WEIGHT) THICKNESS (μm) 100 100 100 100 100 100 100 100 EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- COMPARATIVE PLE 9 PLE 10 PLE 11 PLE 12 PLE 13 PLE 14 EXAMPLE 1 ADHESIVE DONEPEZIL 20 24 12 12 25 10 4 LAYER (% BY WEIGHT) ACRYLIC ADHESIVE 60 51 58 58 63 80 0 A (% BY WEIGHT) ACRYLIC ADHESIVE 0 0 0 0 0 0 96 B (% BY WEIGHT) DIISOPROPYL 0 15 0 0 0 0 0 SEBACATE (% BY WEIGHT) DIISOPROPYL 10 0 20 15 8 0 0 ADIPATE (% BY WEIGHT) ISOPROPYL 0 10 10 15 4 0 0 MYRISTATE (% BY WEIGHT) 2-OCTYLDODECANOL 10 0 0 0 0 0 0 (% BY WEIGHT) LIQUID PARAFFIN 0 0 0 0 0 10 0 (% BY WEIGHT) THICKNESS (μm) 100 100 100 100 100 100 100 Examples 15 to 23 [0104] Donepezil, ethyl cellulose (product name: “ETHOCEL Premium,” manufactured by The Dow Chemical Company, viscosity: 7 cps), ethyl cellulose (product name: “ETHOCEL Premium,” manufactured by The Dow Chemical Company, viscosity: 100 cps), triacetin, triethyl citrate, diisopropyl adipate, and isopropyl myristate were mixed in compositional weight ratios shown in TABLE 2. Then ethanol was added to the mixtures such that the concentration of solids was 25% by weight, and the resultant mixtures were stirred until uniform to thereby produce reservoir layer solutions. [0105] Next, 38 μm-thick polyethylene terephthalate films subjected to silicone release treatment were prepared, and the above-prepared reservoir layer solutions were applied to the silicone release-treated surfaces of the polyethylene terephthalate films and dried at 80° C. for 30 minutes to thereby produce first stacked bodies with reservoir layers with thicknesses shown in TABLE 2 formed on the silicone release-treated surfaces of the polyethylene terephthalate films. [0106] Donepezil, the acrylic adhesive A, diisopropyl adipate, and isopropyl myristate were mixed in compositional weight ratios shown in TABLE 2. Then ethyl acetate was added to the mixtures such that the concentration of solids was 22% by weight, and the resultant mixtures were stirred until uniform to thereby produce adhesive layer solutions. [0107] Separately, 38 μm-thick polyethylene terephthalate films subjected to silicone release treatment were prepared, and the above-prepared adhesive layer solutions were applied to the silicone release-treated surfaces of the polyethylene terephthalate films and dried at 60° C. for 30 minutes to thereby produce second stacked bodies with adhesive layers with thicknesses shown in TABLE 2 formed on the silicone release-treated surfaces of the polyethylene terephthalate films. [0108] Then 38 μm-thick polyethylene terephthalate films used as substrates were prepared and placed over the above-produced first stacked bodies such that one sides of the substrates faced the reservoir layers of the first stacked bodies. The reservoir layers of the first stacked bodies were transferred to, stacked on, and integrated with the substrates. [0109] Next, these substrates were placed over the second stacked bodies such that the reservoir layers on the substrates faced the adhesive layers of the second stacked bodies. The adhesive layers of the second stacked bodies were transferred to, stacked on, and integrated with the reservoir layers, and patches were thereby produced. [0000] TABLE 2 COMPAR- ATIVE EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- PLE 15 PLE 16 PLE 17 PLE 18 PLE 19 PLE 20 PLE 21 PLE 22 PLE 23 PLE 2 RESERVOIR DONEPEZIL (% BY WEIGHT) 50 50 40 40 40 40 50 50 50 40 LAYER ETHYL CELLULOSE 7 cps 50 50 40 40 40 40 0 0 0 40 (% BY WEIGHT) ETHYL CELLULOSE 100 cps 0 0 0 0 0 0 25 25 25 0 (% BY WEIGHT) TRIACETIN (% BY WEIGHT) 0 0 20 0 0 0 10 5 25 20 TRIETHYL CITRATE 0 0 0 20 0 0 0 0 0 0 (% BY WEIGHT) DIISOPROPYL ADIPATE 0 0 0 0 20 0 0 0 0 0 (% BY WEIGHT) ISOPROPYL MYRISTATE 0 0 0 0 0 20 15 20 0 0 (% BY WEIGHT) THICKNESS (μm) 80 60 50 50 50 50 70 70 70 50 ADHESIVE DONEPEZIL (% BY WEIGHT) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 LAYER ACRYLIC ADHESIVE A 98.5 78.5 78.5 78.5 78.5 78.5 78.5 78.5 78.5 0 (% BY WEIGHT) ACRYLIC ADHESIVE B 0 0 0 0 0 0 0 0 0 78.5 (% BY WEIGHT) DIISOPROPYL ADIPATE 0 10 10 10 10 10 10 10 10 10 (% BY WEIGHT) ISOPROPYL MYRISTATE 0 10 10 10 10 10 10 10 10 10 (% BY WEIGHT) THICKNESS (μm) 40 40 40 40 40 40 40 40 40 40 Comparative Example 1 [0110] Donepezil and the acrylic adhesive B were mixed such that the mixture contains 4% by weight of the donepezil and 96% by weight of the acrylic adhesive B, and ethyl acetate was added such that the concentration of solids was 22% by weight. The resultant mixture was stirred until uniform to produce an adhesive layer solution. A patch including an adhesive layer having a thickness of 100 μm was produced as in Example 1 except that the above-produced adhesive layer solution was used. Comparative Example 2 [0111] A patch including an adhesive layer having a thickness of 40 μm was produced as in Example 17 except that the acrylic adhesive B was used instead of the acrylic adhesive A. [0112] The storage stability (in terms of content) and storage stability (in terms of precipitation state) of each of the patches obtained in the Examples and Comparative Examples were measured as described later, and the results are shown in TABLEs 3 and 4. In addition, each of the patches obtained in the Examples and Comparative Examples was subjected to a permeability test as described later to measure the cumulative skin permeation amount of donepezil. The results are shown in TABLEs 3 and 4. For each of the patches obtained in Examples 17, 21, and 23, the amount of transdermal delivery was measured as described later. The results are shown in TABLE 5. (Storage Stability (in Terms of Content)) [0113] Six test pieces with an area of 3 cm 2 were cut from a patch immediately after production and wrapped and sealed with a light-shielding wrapping material. Three of the test pieces were stored at 4° C. for two weeks, and the other three were stored at 60° C. for two weeks. After the storage, donepezil in each of the adhesive layers and reservoir layers was extracted with ethyl acetate, and the total amounts of donepezil in the adhesive layers and reservoir layers were quantified by HPLC. The total amount of donepezil in the adhesive layers and reservoir layers in the three test pieces stored at 4° C. was denoted by W 4 , and the total amount of donepezil in the adhesive layers and reservoir layers in the three test pieces stored at 60° C. was denoted by W 60 . The ratio of the remaining drug was computed using the following formula (1). The remaining ratio was entered in a “content” field in the “storage stability” row in TABLE 3. [0000] Remaining ratio (% by weight)=100× W 60 /W 4   (1) (Storage Stability (in Terms of Precipitation State)) [0114] A square flat test piece with 3-cm side was cut from a patch immediately after production. The test piece was wrapped and sealed with a light-shielding wrapping material and stored at 25° C. for one month. After one month, the test piece was observed from the adhesive layer side, and the precipitation state of crystals was observed under a transmission microscope at 40×. [0115] A square flat test piece with 3-cm side was cut from the patch immediately after production. The test piece was wrapped and sealed with a light-shielding wrapping material and stored at 40° C. for one month. After one month, the test piece was observed from the adhesive layer side, and the precipitation state of crystals was observed under a transmission microscope at 40×. [0116] A square flat test piece with 3-cm side was cut from the patch immediately after production. The test piece was wrapped and sealed with a light-shielding wrapping material and stored at 60° C. for one month. After one month, the test piece was observed from the adhesive layer side, and the precipitation state of crystals was observed under a transmission microscope at 40×. [0117] When the crystals of donepezil were uniformly precipitated on the surface of the adhesive layer of a test piece, this test piece was evaluated as “good.” When the crystals of donepezil were not uniformly precipitated, the test piece was evaluated as “bad.” For each patch including the reservoir layer, the crystals of donepezil precipitated on the surface of the reservoir layer that faced the adhesive layer were projected in the direction of the thickness of the adhesive layer, and all the crystals of donepezil precipitated on the surface of the reservoir layer that faced the adhesive layer were considered to be precipitated on the surface of the adhesive layer. (Permeability Test) [0118] A test piece with 1-cm side was cut from a patch immediately after production. Dorsal skin removed from a hairless mouse (male, 8 to 10 weeks old) was fixed on a Franz diffusion cell maintained at 37° C., and the test piece was applied to the upper end of the skin through the adhesive layer of the test piece. Note that a physiological saline solution with its pH adjusted to 7.2 was used as a receptor solution, and the lower end of the skin was immersed in the receptor solution. [0119] The receptor solution on the lower side of the skin was collected 2, 4, 6, 22, and 24 hours after the test piece was applied to the skin, and the concentration of donepezil were measured by HPLC. More specifically, three test pieces were prepared, and the concentration of donepezil was measured for each test piece in the manner described above after 2, 4, 6, 22, and 24 hours. The permeation amount of donepezil determined from the donepezil concentration and the amount of the receptor solution was computed at each time point. The arithmetic mean of the permeation amounts of donepezil computed for the test pieces was determined at each time point, and the computed value was used as the cumulative skin permeation amount of donepezil. Note that when the permeation amounts of donepezil were computed after 4, 6, 22, and 24 hours, since the receptor solution had been collected before these time points, the permeation amounts were corrected on the basis of the amount of the receptor solution collected. [0120] The permeation test was not performed for Comparative Examples 1 and 2 because the results for the storage stability (in terms of content) were lower than 90% by weight. (Transdermal Delivery Amount) [0121] Fifteen test pieces with an area of 3 cm 2 were cut from a patch immediately after production. Three test pieces were applied to each of four rabbits with shaved backs (male, 16 to 18 weeks old) through the adhesive layers of the test pieces. The rest of three test pieces were wrapped and sealed with a light-shielding wrapping material and stored at 4° C. One test piece was removed from the back skin one, four, and seven days after the application. Donepezil in the adhesive layer and reservoir layer of each test piece was extracted with ethyl acetate, and the total amount of donepezil in the adhesive layer and reservoir layer was quantified by HPLC (high performance liquid chromatography). The arithmetic mean of the total amounts of donepezil in test pieces was computed as a mean value W 1 . For the three test pieces stored at 4° C. and not applied to the back skin, one test piece was collected one, four, and seven days after the start of the measurement. Donepezil in the adhesive layer and reservoir layer of each test piece was extracted with ethyl acetate, and the total amount W 0 of donepezil in the adhesive layer and reservoir layer was quantified by HPLC (high performance liquid chromatography). The transdermal delivery amount of donepezil was computed using the following formula and entered in a “transdermal delivery amount” field in TABLE 5. [0000] Delivery amount (mg)= W 0 −W 1 [0000] TABLE 3 EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- PLE 1 PLE 2 PLE 3 PLE 4 PLE 5 PLE 6 PLE 7 PLE 8 STORAGE CONTENT (% BY WEIGHT) 97.7 98.1 97.6 95.7 98.3 98.3 97.9 99.2 STABILITY PRECIPITATION 25° C. GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD STATE 40° C. BAD BAD GOOD GOOD GOOD GOOD GOOD GOOD 60° C. BAD BAD BAD BAD GOOD GOOD GOOD GOOD PERMEABILITY 2 HOURS 0.009 0.017 0.010 0.010 0.015 0.017 0.020 0.004 TEST 4 HOURS 0.020 0.041 0.025 0.027 0.042 0.043 0.050 0.012 6 HOURS 0.030 0.063 0.042 0.048 0.069 0.072 0.082 0.020 22 HOURS 0.121 0.282 0.244 0.310 0.361 0.345 0.426 0.157 24 HOURS 0.131 0.304 0.271 0.341 0.404 0.390 0.469 0.174 COMPAR- ATIVE EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- PLE 9 PLE 10 PLE 11 PLE 12 PLE 13 PLE 14 PLE 1 STORAGE CONTENT (% BY WEIGHT) 99.7 99.1 97.0 97.9 99.6 98.1 75.2 STABILITY PRECIPITATION 25° C. GOOD GOOD GOOD GOOD GOOD GOOD BAD STATE 40° C. GOOD GOOD GOOD GOOD GOOD BAD BAD 60° C. GOOD GOOD GOOD GOOD GOOD BAD BAD PERMEABILITY 2 HOURS 0.005 0.012 0.011 0.020 0.008 0.009 — TEST 4 HOURS 0.015 0.033 0.030 0.050 0.022 0.023 — 6 HOURS 0.027 0.056 0.050 0.082 0.039 0.039 — 22 HOURS 0.169 0.350 0.270 0.426 0.220 0.229 — 24 HOURS 0.184 0.404 0.318 0.469 0.251 0.254 — [0000] TABLE 4 COMPAR- ATIVE EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- EXAM- PLE 15 PLE 16 PLE 17 PLE 18 PLE 19 PLE 20 PLE 21 PLE 22 PLE 23 PLE 2 STORAGE CONTENT (% BY WEIGHT) 98.1 97.3 98.5 96.9 97.8 97.4 98.8 98.4 98.5 80.4 STABILITY PRECIPITATION 25° C. GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD STATE 40° C. BAD GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD 60° C. BAD GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD GOOD PERMEABILITY 2 HOURS 0.000 0.008 0.011 0.006 0.005 0.007 0.011 0.016 0.009 — TEST 4 HOURS 0.001 0.025 0.029 0.018 0.014 0.022 0.039 0.051 0.029 — 6 HOURS 0.002 0.045 0.049 0.032 0.024 0.039 0.069 0.089 0.051 — 22 HOURS 0.040 0.213 0.290 0.210 0.189 0.245 0.372 0.540 0.256 — 24 HOURS 0.047 0.232 0.309 0.229 0.210 0.266 0.443 0.571 0.288 — [0000] TABLE 5 EXAMPLE EXAMPLE EXAMPLE 17 21 23 TRANSDERMAL ONE 0.50 0.46 0.38 DELIVERY DAY AMOUNT (mg) FOUR 1.00 0.95 0.62 DAYS SEVEN 1.45 1.31 0.75 DAYS INDUSTRIAL APPLICABILITY [0122] The patch of the present invention ensures high storage stability of donepezil or a salt thereof and allows stable transdermal administration of the donepezil or salt thereof in an amount that provides a pharmaceutical effect. Therefore, the patch of the invention can be preferably used as a transdermal absorption preparation for Alzheimer's disease. REFERENCE SIGNS LIST [0000] 1 substrate 2 adhesive layer 3 reservoir layer 4 intermediate layer 5 release paper

Provided is a patch that ensures high storage stability of donepezil or a salt thereof and allows stable transdermal administration of the donepezil or salt thereof in an amount that provides a pharmaceutical effect. The patch includes a substrate 1 and an adhesive layer 2 stacked on and integrated with one surface of the substrate 1 and containing donepezil or a salt thereof and an acrylic adhesive containing a copolymer obtained by copolymerizing monomers that each contain a (meth)acrylic acid ester of a saturated aliphatic alcohol and do not contain vinylpyrrolidone.

[0001] Cross-reference to related patent application, if any: None. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to the field of vehicle occupant protection systems and more particularly, to those which involve the use of inflatable devices. In particular, the present invention relates to the use of an inflatable headliner system. The system is arranged to inflate upon an accident/impact to deform the headliner downwardly, away from the vehicle roof, and toward the lower portions of the vehicle interior. In the most preferred embodiment, the inflatable headliner system includes a plurality of inflatable portions which extend about its perimeter, and additional inflatable portions cross transversely in the event cross bows are included in the vehicle roof. [0004] 2. Description of the Prior Art [0005] A large number of air bag systems for occupant protection in vehicles are known. These include air bag systems mounted within the steering column, instrument panel, and other interior locations to assist occupants in the event of frontal impacts. In recent years, side air bags which may be deployed from the area around the side rail of the vehicle roof have also become popular. Air bags may also be located within the seat for deployment along the side of the vehicle when triggered by side impact sensors or the like. [0006] There is an increasing emphasis on providing impact countermeasures for all parts of an occupant's body, including the head, and countermeasures are currently employed in headliner systems, most of which involve the use of a deformable material (such as a urethane elastomer) located behind the interior or “A” surface of the headliner. Such countermeasures provide varying degrees of protection and also involve several disadvantages from the standpoint of cost, assembly time, and the like. They require so much space in some cases that the vehicle cockpit volume is substantially diminished. While no prior art is known by the present inventors which would result in the integration of an inflatable fabric within a headliner system, the inventors believe that an air cushion urging the headliner system downwardly at the time of an accident/impact would enhance overall occupant protection capabilities in a vehicle. Such an inflatable headliner system would represent a substantial advance in this art. FEATURES AND SUMMARY OF THE INVENTION [0007] A primary feature of the present invention is to provide an inflatable system integrated into the headliner of a vehicle. [0008] Another feature of the present invention is to provide an inflatable headliner system which is readily adaptable to a wide variety of vehicle roof structures. [0009] Yet another feature of the present invention is to provide an inflatable headliner system which does not significantly reduce the interior volume of the vehicle cockpit. [0010] A different feature of the present invention is to provide an inflatable headliner system which includes inflatable and, in some cases, non-inflatable portions. [0011] Yet still another feature of the present invention is to provide an inflatable headliner system which eliminates the need for complex, multi-component head impact countermeasure components. [0012] A still further feature of the present invention is to provide inflatable portions around the perimeter of an inflatable headliner system, and in a preferred form to provide air passageways between the inflatable portions. [0013] Another feature of the present invention is to provide inflatable portions which extend transversely of the vehicle where cross bows are used in the vehicle roof. [0014] Another feature of the present invention is to provide an inflatable headliner system in which openings are provided for vehicle accessories such as visors, mirrors, grab handles, coat hooks, sun roofs, and the like. [0015] How the foregoing and other features of the present invention are accomplished individually, collectively, or in various subcombinations, will be described in the following detailed description of the preferred embodiment taken in conjunction with the FIGURE. Generally, however, they are accomplished in an inflatable headliner system which includes an inflatable component integrated into the located as a sandwiched layer between other headliner layers such as structural layers, or convenience layers (e.g. sound absorption layers, cushion layers, etc.). The headliner may include various known laminate or composite layers. The inflatable component preferably includes a thin fabric sheet and a plurality of inflatable and non-noninflatable portions. The inflator(s) for the system may be located in the headers, the side rails or any of the “A”, “B”, “C” or “D” pillars. When a deployment event occurs, the headliner system is deformed urging it downwardly and away from the vehicle roof. In further preferred embodiments, inflatable portions may be separated by air flow passageways, and in vehicles which employ cross bows, additional inflatable portions may be provided beneath them. [0016] Other ways in which the features of the present invention are accomplished will become apparent to those skilled in the art after they have read this specification and are deemed to fall within the scope of the present invention if they fall within the scope of the claims which follow. BRIEF DESCRIPTION OF THE DRAWINGS [0017] [0017]FIG. 1 is an exploded view of a headliner air bag system according to a preferred embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0018] Before proceeding with the description of the preferred embodiment, several general comments can be made about the applicability and the scope thereof. [0019] First, one particular headliner system is illustrated in the FIGURE, namely one having layers of fabric, structural foam, and a reinforcement convenience layer. In addition, a few locations for attachment of vehicle interior accessories are shown, such as visors, a dome light, grab handles, a coat hook, etc. It should be understood at the outset that the present invention has broad applicability to headliner systems for cars, SUV's, vans, light trucks, and other vehicles where an inflatable headliner system can be used to enhance vehicle safety. [0020] In addition to the overall shape and dimensions of the headliner, a wide variety of other openings can be provided through the headliner for the attachment of such other accessories as infotainment devices, air ducts, computer ports, additional lighting, power outlets, sun roofs, etc. It is becoming increasingly important to motor vehicle manufacturers to provide a wide range of passenger accessible components, and overall structural and aesthetic design flexibility is enhanced when the headliner or roof area of a vehicle can be employed. [0021] The present invention is illustrated for use with a layered headliner system which includes an interior fabric layer, an intermediate structural layer, and a convenience layer which abuts the vehicle roof. A large number of different headliner constructions are known in the art, and the present invention can be used with them as well. For example, the fabric and foam layers may be readily combined into a single layer, or more layers of material can be employed, typically in higher end vehicles where a plush feel is desirable. [0022] The present specification illustrates the inflatable portion of the headliner system located between the lowermost two layers of the headliner structure, i.e., between the fabric and a structural layer. Such location is not critical, and the invention would perform its intended function if the inflatable component was located between the structural and the convenience layers. Alternately, the inflatable portion may be the “A” surface layer, or a backside layer. [0023] With regard to the inflatable layer itself, it is illustrated as having a non-inflatable center surrounded by a plurality of inflatable portions, some of which are connected by narrow air flow passageways. Neither a plurality of portions or passageways are required. For example, the inflatable portions could be one sack or bag around the entire periphery (thereby eliminating the air passageways) or a larger number of inflatable portions can be provided than are illustrated. Furthermore, the portions can extend further toward the center of the air bag layer than is shown in the drawings. Moreover, if roof bows are located in the vehicle, inflatable portions can be located beneath them for reasons discussed in greater detail below. Also, the number of ignitors (which are well known in and of themselves and which create a large volume of inert gas, such as nitrogen, at the time a remotely located sensor detects a sudden deceleration or impact) can be variously located within the inflatable headliner system. In the illustration, a single ignitor is illustrated on one side, but a similar ignitor can be located on the opposite side and the number can be variously selected by those familiar with air bag design. Moreover, the ignitor(s) can be located in a variety of areas, e.g., in the “A”, “B”, “C” or “D” pillars of the vehicle, or in the front or rear headers, or in the side rails. [0024] Additionally, it should be made very clear that the illustrated system is shown with each of four layers formed for a particular vehicle (e.g. by thermoforming). The inflatable component can be integrated in a wide variety of locations and shapes. [0025] Finally, the materials used for the construction of the inflatable layer, both the inflatable and non-inflatable portions thereof, can be selected from any of those currently in use for front impact or side impact air bags. The preferred material is a fabric, some of which is formed into pockets. The fabric may be nylon or other natural or synthetic woven or non-woven fabrics. [0026] Proceeding now to the description of the preferred embodiment, the FIGURE illustrates an inflatable headliner system 10 of the type which would be used with an SUV. As mentioned above, system 10 could be configured and dimensioned to be used with cars, SUVs, vans, light trucks, i.e. any vehicle which has a roof and a headliner system located between the roof and vehicle occupants. [0027] The illustrated system 10 is shown to include three conventional headliner layers, namely an inner fabric layer 12 , an intermediate structural foam layer 14 and a reinforcement or convenience layer 16 . Each layer is formed for structural or aesthetic purposes, as is very well known in the vehicle headliner art. For example, layers 12 , 14 and 16 (as well as the inflatable layer to be described layer) can be simultaneously or individually thermoformed (if materials which soften upon the application of heat are used), or they may be laid up, sprayed, molded or constructed using these or other known headliner fabrication methods. The layers 12 , 14 and 16 , in and of themselves, are well known and further details about them need not be provided here. [0028] The exploded view of the FIGURE shows layers 12 , 14 , and 16 to be separate from one another, but they could be combined (in various subcombinations) or some of the layers might be eliminated in their entirety or other layers added. All that is really required for the present invention is a layer (which may even be the inflatable layer to be discussed below) which can deform toward the vehicle occupant(s) and away from the vehicle roof at the time inflation and occupant protection is called for. [0029] As far as materials are concerned, the individual layers can be made from fabrics, foams, fibers, molded fiberboard, corrugated paper or plastics, etc. or combinations of the foregoing materials, again as is well known in the art. [0030] Referring again to the FIGURE, a number of openings are formed in each of layers 12 , 14 and 16 to illustrate several common vehicle accessories, but not to in any way limit the number, sizes or location of such openings. At the center 18 of the front end 20 of the system 10 , an opening 22 is provided for a light or other overhead component (mirror, sun glasses holder, garage door opener, holder, etc.). On either side of the opening 22 , two additional openings 24 and 25 are provided for the pivoting and inboard couplers, respectively, for sun visors. A pair of grab handle attachment openings 28 are provided along the sides of each of layers 12 , 14 and 16 , and finally a coat hook attachment opening 30 is provided in the rear portion of each of the three layers 12 , 14 and 16 . The accessories are, in and of themselves, very well known and need not be described here. [0031] An inflatable layer 35 is shown in the FIGURE located in the preferred embodiment between fabric layer 12 and structural layer 14 . Air bag layer 35 is preferably pliable or thermoformable to allow it to conform to the shapes of the layers on either side of it, and it includes a center portion 37 and a periphery 39 . Located about periphery 39 are at least one, and preferably a plurality of, inflatable sacks 40 . The inflatable sacks 40 may be connected by air flow passageways 41 if desired, and the number of inflatable sacks 40 , their size and precise location can be varied by those skilled in the air bag art after they have read this specification. Inflatable sacks 40 are bladders or pockets which are collapsed until a gas is forced into them at the time deployment and headliner deformation is desired. [0032] Air bag ignition systems themselves are very well known, as are the sensors used to detect a deployment event. Accordingly details will not be provided here. What is shown in the FIGURE is an illustrative ignitor 42 and a wire 43 leading to a sensor (not shown). As stated earlier, the number of ignitors and the location thereof can vary. While in the preferred and illustrated embodiment, the ignitor 42 is shown as part of the inflatable layer 35 , one or more of them could be located in the “A”, B″, “C” or “D” pillars of the vehicle, or at any other suitable locations. [0033] One additional feature and embodiment will now be described, i.e. the use of additional inflatable sacks 51 if cross-bows are provided in the vehicle in which system 10 will be used. This is desirable in such vehicles because the roof structure at the location of the cross bows will be sufficiently rigid to allow deforming the inflatable layer 35 downwardly upon the occurrence of a deployment event. Unless cross bows are present, the roof metal of the vehicle may yield, reducing the downwardly directed force of the expanding sacks 51 . In the FIGURE, cross bow locations are illustrated by dashed lines 50 . [0034] While the present invention has been described in connection with a preferred and an alternate embodiment, it is not to be limited in any sense by such disclosures (size, configuration, relative dimensions, materials, numbers of components, etc.) but it is to be limited solely by the scope of the claims which follow.

An inflatable headliner system is mounted below a vehicle roof. It deforms upon an accident/impact toward vehicle occupants. In the preferred embodiment, inflatable portions surround a central section of an inflatable layer. Individual portions may be separated by passageways. If cross bows are employed in the vehicle roof structure, an embodiment utilizes inflatable portions beneath the cross bows.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority based upon U.S. Provisional Patent Application Ser. No. 60/281,926 filed Apr. 6, 2001. [0002] This application is also related to U.S. patent application Ser. Nos. 10/ ______ (Atty. Docket No. 5181-89400) entitled “A Maximal Tile Generation Technique and Associated Methods of Designing and Manufacturing VLSI Circuits” and Ser. No. 10/ ______ (Atty. Docket No. 5181-89300) entitled “Active Region Management Techniques and Associated Methods of Designing and Manufacturing VLSI Circuits”, both of which were filed on______ , 2002, assigned to the Assignee of the present application and hereby incorporated by reference as if reproduced in their entirety. BACKGROUND [0003] 1. Technical Field [0004] This relates to the design and manufacture of very large scale integrated (“VLSI”) circuits and, more particularly, to a method for routing connections between component tiles of a VLSI circuit suitable for use in conjunction with the design and manufacture of VLSI circuits. [0005] 2. Description of the Relevant Art [0006] A VLSI circuit is typically composed of a plurality of generally horizontal layers, each layer having a plurality of generally rectangular shaped components positioned thereon. VLSI circuit designers commonly refer to these generally rectangular shaped components as “component tiles” and to the rectangular shaped open spaces that surround the component tiles as “space tiles.” Component tiles that are to be connected on a VLSI circuit are said to form a “net”, while any component tile not connected to a particular net is considered to be an obstruction to that net. Two tiles are said to be “adjacent” if they touch along their edges and “overlapping” if there is even a single point located within the interior of both tiles. A set of tiles positioned within a routing area is said to be “maximal” if no two tiles are either overlapping or adjacent on their left or right edges. [0007] One step in the design of a VLSI circuit is to select the wire paths that extend through the space tiles to connect the electrically equivalent component tiles that form nets. A current technique used to determine these paths utilizes a tile expansion algorithm. More specifically, clear space around the component tiles forming a net is fractured into maximal space tiles. Adjoining ones of these maximal space tiles are used to define the most efficient tile path between two components. The path of the actual connection between the components, known as the wire path, is then defined as the route through the space tile path from the center of the component source tile to the center of the component destination tile. [0008] The aforementioned technique for selecting the wire paths for a VLSI circuit design suffers from two drawbacks, both of which may add to the cost of VLSI circuits manufactured in accordance with the design. First, if defined in accordance with the above-described manner, a tile path is not necessarily the optimal tile path through the clear space. Second, since the width of a tile path is typically much larger than the width of a wire path, multiple wire paths may exist through a given tile path. If the wire path located within the tile path is arbitrarily selected, the selected wire path is not necessarily the most efficient wire path potentially located within the tile path. SUMMARY [0009] Disclosed herein is a method and associated apparatus for the design and manufacture of VLSI circuit which incorporates therein a method for routing connections between component tiles of the VLSI circuit being designed. In accordance with the disclosed method, maximal component tile and maximal space tile lists are constructed and, from the constructed lists, the maximal component and maximal space tiles are positioned on the routing area(s). Optimal tile path and minimum cost wire path between pins that are CTs to be connected are determined and, utilizing the determined wire path, a VLSI circuit design is generated. The minimum cost path from a starting tile S to a destination tile T is determined by creating a priority queue and a search tree ST with the starting tile S as its root. While the priority queue is not empty, a low cost tile E neighboring the starting tile S is popped and, if a tile path to destination tile T is found, the cost of the tile path is evaluated and saved as the minimum cost point path. Otherwise, for each tile F neighboring the tile E, the search tree is expanded and, for a tile path having an estimated cost greater than the current cost, the search path is pruned. Otherwise, the search is expanded by adding the tile F (with corresponding minimum cost CE)) to the priority queue Q and inserting the tile F into the search tree as a child node of the tile E. BRIEF DESCRIPTION OF THE DRAWINGS [0010] [0010]FIG. 1 is a block diagram of a computer system in which VLSI circuit design software resides. [0011] [0011]FIG. 2 is a flow chart of a method for designing and manufacturing VLSI circuits. [0012] [0012]FIG. 3 a is a flow chart of a method, suitable for use with the method of designing and manufacturing VLSI circuits of FIG. 2, for reconfiguring a routing area into an arrangement of maximal component tiles and maximal space tiles. [0013] [0013]FIGS. 3 b - 1 through 3 b - 2 is a flow chart of a method, suitable for use with the method of designing and manufacturing VLSI circuits of FIG. 2, of determining an optimal tile path and minimum cost wire path between pins that are CTs to be connected. [0014] [0014]FIG. 4 is a top view of first and second routing areas, each forming a respective layer of a VLSI circuit design and having at least one component tile to be connected into a net. [0015] [0015]FIG. 5 is a top view of the first routing area of FIG. 4 after reconfiguration into an arrangement of maximal component tiles and maximal space tiles. [0016] [0016]FIG. 6 is a top view of the second routing area of FIG. 4 after reconfiguration into an arrangement of maximal component tiles and maximal space tiles. DETAILED DESCRIPTION [0017] Referring first to FIG. 1, a computer system 1 , for example, a personal computer (“PC”), file server or other type of computer, in which VLSI circuit design software resides will now be described in greater detail. The computer system 1 is comprised of a processor subsystem 2 , a memory subsystem 3 and an input/output (“I/O”) subsystem 4 coupled together by a bus subsystem 5 . The bus subsystem 5 encompasses the main system bus and any local or other types of busses that collectively couple the processor subsystem 2 , the memory subsystem 3 and the I/O subsystem 4 to one another. As used herein, the terms “couple” or “coupled” refer broadly to either a direct or an indirect connection between the referenced elements. [0018] The processor subsystem 2 encompasses the collective processing capability of the computer system 1 , including the central processing unit (“CPU”) as well as any secondary processing devices, for example, an arithmetic processing unit, coupled to the CPU by the bus subsystem 5 . Similarly, the memory subsystem 3 encompasses the collective storage capability of the computer system 1 , including main, auxiliary, cache and any other memory accessible by the processor subsystem 2 via the bus subsystem 5 . Finally, the I/O subsystem 4 encompasses any and all I/O devices, for example, floppy, CD-ROM or DVD drives, coupled to the bus subsystem 5 , for writing data to or reading data from the processor subsystem 2 or the memory subsystem 3 . The I/O subsystem 4 also encompasses any data communications equipment (“DCE”), for example, network interface cards or modems, which couple the computer system 1 to data terminal equipment (“DTE”), for example, a second PC, file server or web server, via a local area network (“LAN”), wide area network (“WAN”), intranet, internet or other type of network. [0019] [0019]FIG. 1 further shows plural software modules, specifically, a first software module 6 for providing the computer system 1 with VLSI circuit design functionality, a second software module 7 for providing the computer system 1 with maximal tile generation functionality, a third software module 8 for providing the computer system 1 with active region management functionality and a fourth software module 9 for providing the computer system 1 with connection routing functionality. Each of the software modules 6 through 9 is comprised of a series of instructions which are encoded in the memory subsystem 3 as computer readable program code and executable by the processor subsystem 2 . Typically, the VLSI circuit design module 6 , the maximal tile generation module 7 , the active region management module 8 and the connection routing module 9 will be stored in the auxiliary memory of the memory subsystem 3 prior to the execution thereof. A transportable computer usable medium 10 , for example, a floppy disk, CD-ROM or file transfer software, is used to copy the VLSI circuit design module 6 , the maximal tile generation module 7 , the active region management module 8 and the connection routing module 9 into the auxiliary memory of the memory subsystem 3 . [0020] As illustrated in FIG. 1, the functionality provided by the software modules 6 through 9 may be encoded in the memory subsystem 3 and/or the computer usable medium 10 as discrete computer programs, each containing computer readable program code. Alternately, the functionality provided by the software modules 6 through 9 may be encoded in the memory subsystem 3 and/or the computer usable medium 10 as separate subroutines of a single computer program containing plural computer readable program subcodes. Furthermore, while any of the software modules 6 through 9 may be executed separately, typically, the VLSI circuit design module 6 will be initially executed by the processor subsystem 3 . The VLSI circuit design module 6 will then periodically call selected ones of the maximal tile generation module 7 , the active region management module 8 and the connection routing module 9 to perform certain functions during the design of a VLSI circuit. Of course, any one of the software modules 6 through 9 may call any other one of the software modules 6 through 9 to perform certain functions on its behalf. [0021] Referring next to FIG. 2, a method for designing and manufacturing VLSI circuits will now be described in greater detail. The method commences at step 11 with the execution of the VLSI circuit design module 6 by the processor subsystem 2 . The method proceeds to step 12 where one or more routing areas are defined and a collection of component tiles are positioned on each routing area using the VLSI circuit design module 6 . Generally, a routing area comprises the surface area of a layer of an integrated circuit on which component tiles are positioned. When plural routing areas are defined by the VLSI circuit design module 6 , the integrated circuit being designed is a multi-layer integrated circuit and each routing area comprises the surface of a respective layer of the multi-layer integrated circuit. [0022] For example, FIG. 4 illustrates the components tiles (“CT”s) of a multi-layer integrated circuit design having two layers. The CTs 92 , 94 and 96 are positioned within a first routing area 90 of a first, or upper, layer. Also shown in FIG. 4 is CT 98 , which is illustrated in phantom because it resides on a second routing area 90 ′ of a second, or lower, layer located beneath the routing area 90 . In the VLSI circuit design illustrated in FIG. 4, the CTs 92 , 96 and 98 , also known as pins, are on the same net while the CT 94 is an obstruction. Thus, the CTs 92 , 96 and 98 must now be connected while avoiding the CT 94 . [0023] While, in the description to follow, the routing areas 90 and 90 ′ are oftentimes described with respect to a vertical axis, hereafter termed the “S” axis, which extends from S 0 to S 8 , and a horizontal axis, hereafter termed the “D” axis, which extends from D 0 to D 9 , it should be clearly understood that the use of these terms is not intended to imply or suggest that the routing areas 90 and 90 ′ have a particular orientation, either horizontal or vertical, relative to the VLSI circuit being designed. Likewise, the description of a first span (or segment thereof) of the routing areas 90 or 90 ′ as being located above or below a second span (or segment thereof) is not intended to imply or suggest that the first and second spans are oriented in either the horizontal or vertical plane. Rather, the use of these terms is merely intended to describe their relative location within a common plane without regard to the specific orientation of that plane. [0024] Accordingly, the method proceeds to step 14 where the first routing area 90 is selected for reconfiguration into maximal component and space tiles. The method then continues on to step 16 for construction of maximal component tile and maximal space tile lists for the routing area 90 . The CTs 92 , 94 and 96 of the routing area 90 are all maximal component tiles because there are no overlapping tiles or adjacent tiles on either the left or right sides thereof. However, the open space of the routing area 90 needs to be divided into one or more maximal space tiles. A suitable method to perform this operation is disclosed in co-pending U.S. patent application Ser. No. 10/ ______ (Atty. Docket No. 5181-89400) entitled “A Maximal Tile Generation Technique and Associated Methods of Designing and Manufacturing VLSI Circuits” and previously incorporated by reference. However, as the current example differs from that described in the above-referenced patent application in that all of the component tiles positioned on the routing area 90 are already maximal component tiles, the method set forth in the above-referenced application shall later be applied to the routing area 90 illustrated in FIG. 4. [0025] After constructing maximal component tile and maximal space tile lists for the routing area 90 in a manner to be more fully described below, the method proceeds to step 17 where it is determined if there are additional routing area for which maximal component tile and maximal space tile lists are to be constructed. As maximal component tile and maximal space tile lists must still be constructed for the routing area 90 ′, the method proceeds to step 18 for selection of the routing area 90 ′ and then returns to step 16 for construction of maximal component tile and maximal space tile lists for the routing area 90 ′. After constructing maximal component tile and maximal space tile lists for the routing area 90 ′ in a manner to be more fully described below, the method proceeds to step 17 where it is determined that maximal component tile and maximal space tile lists have been constructed for all routing areas. Accordingly, the method then proceeds to step 19 where the maximal component tile and maximal space tile lists constructed at step 16 are used to position the maximal component tiles and the maximal space tiles on the routing areas 90 , 90 ′. [0026] After positioning the maximal component and maximal space tiles on the routing areas 90 , 90 ′, the method proceeds to step 20 where the connection routing module 9 determines the optimal tile path and minimum cost wire path between pins that are CTs to be connected. Using the minimum cost wire path between pins that are CTs to be connected, the method continues on to step 24 where the positions of the CTs and the wire path interconnecting the connected CTs are used by the VLSI circuit design module 6 to produce a VLSI circuit design. It should be noted, however, that the foregoing description of a method of designing a VLSI circuit is highly simplified and that numerous steps in the process which are deemed as not being needed for an understanding of the disclosed techniques have been omitted for ease of description. Having completed the design of the VLSI circuit, the method then continues on to step 26 where plural VLSI circuits which conform to the design are manufactured at a facility using conventional manufacturing processes. The method then ends at step 28 . [0027] Turning now to FIG. 3 a , the method by which maximal component tile and maximal space tile lists are determined for the routing area 90 at step 16 will now be described in greater detail. The method commences at step 30 and, at step 32 , a list (AL) of active segments and a list (IL) of inactive segments of a span which extends along a bottom edge 90 a of the routing area 90 are identified. Generally, an “active” segment of a span is a segment which passes through the interior of a component tile or along a lower edge thereof. Conversely, an “inactive” segment of a span is a segment that passes through an unoccupied portion of the routing area or along an upper edge of a component tile. Once active and inactive segments of the span have been identified, a level is then assigned to each segment thereof. The level of a segment is the point, along the S axis, generally aligned with the span of which the active or inactive segment forms a portion thereof. For example, a segment forming part of a span may be described as follows: [DX, DY, SZ] where DX is the point, along the D axis, where the active or inactive segment starts, DY is the point, along the D axis, where the active or inactive segment ends and SZ is the level, along the S axis, of the active or inactive span of which the active or inactive segment forms a portion thereof. [0028] An active segment of a first span may be said to “match” an active segment of a second span if the segments have the same start point DX and the same stop point DY along the D axis but different levels SZ along the S axis. For example, the active segments [D 1 , D 3 , S 1 ] and [D 1 , D 3 , S 2 ] are considered to be matching active segments. Conversely, the term “unmatched” active segments refer to spans which, in addition to having different levels SZ, also have different start points DX, different stop points DY or both. Likewise, an inactive segment of a first span matches an inactive segment of a second span if the segments have the same start and stop points DX and DY but different levels SZ while unmatched inactive segments also have either a different start point DX, a different stop point DY or both. [0029] A “characteristic” of a span is defined by the set of segments which comprises the span. A pair of spans may be deemed as having the same characteristic if every active and inactive segment of a first span of the span pair has a matching active or inactive segment, respectively, in a second one of the span pair. Conversely, a pair of spans may be deemed as having different characteristics if every active and inactive segment of the first span fails to have a matching active or inactive segment, respectively, in the second span. [0030] As may be clearly seen in FIG. 4, neither a lower edge nor an interior of a component tile extends along the bottom edge 90 a of the routing area 90 . Accordingly, the bottom edge 90 a of the routing area 90 has a span comprised of a single inactive segment which extends from DO to D 9 . As may be further seen in FIG. 4, the level of the span is SO. The level of the span is hereby designated as a first stop point SO for a set of stop points for the routing area 90 and the list of active and inactive segments of the span which extends along the bottom edge 90 a of the routing area 90 and is generally aligned with the first stop point SO may be described as follows: AL=Φ; and IL={[D 0 , D 9 , SO]}. [0031] The list of ALs and the list of ILs for the span generally aligned with the first stop point S 0 are hereby designated as a current list of ALs and a current list of ILs, respectively, for the routing area 90 . [0032] Continuing on to step 34 , additional members of the set of stop points for the routing area 90 are identified. These additional stop points for the routing area 90 are those points along the S axis which are generally aligned with either a lower edge of one or more of the CTs 92 , 94 and 96 and/or an upper edge of one or more of the CTs 92 , 94 and 96 . Thus, from the known arrangement of the CTs 92 , 94 and 96 illustrated in FIG. 4, the maximal tile generation module 7 identifies, in an ascending order relative to the S axis, S 1 , S 2 , S 3 , S 4 , S 5 and S 6 as additional members of the set of stop points for the routing area 90 . Finally, an upper edge 90 b of the routing area 90 is designated as a last stop point S 8 of the set of stop points for the routing area 90 . The method then proceeds to step 36 where an empty list of maximal component tiles (CTL) and an empty list of maximal space tiles (STL) are generated. [0033] S 1 , S 2 , S 3 , S 4 , S 5 and S 6 were identified as additional stop points because they are all aligned with one or more of the lower edges of the CTs 92 , 94 and 96 and/or the upper edges of the CTs 92 , 94 and 96 . The edges of the CTs 92 , 94 and 96 are used to identify additional stop points since the edges of a CT indicate transition between active and inactive regions. More specifically, a lower edge of a CT indicates the location of an inactive-to-active transition while an upper edge of a CT indicates the location of an active-to-inactive transition. The stop points are selected to coincide with either inactive-to-active or active-to-inactive transitions because, in accordance with the techniques disclosed herein and to be more fully described below, maximal component and/or space tiles are generated whenever active and/or inactive segments of a first span fails to have a matching active and/or inactive segments along a second span. [0034] At step 38 , it is determined whether there are additional stop points which require examination. If so, the method proceeds to step 40 for selection of a next stop point for examination. At step 42 , a next list of active segments and a next list of inactive segments are identified for a next span generally aligned with a next stop point of the set of stop points. The lists of active and inactive segments of the span generally aligned with the next stop point are generated using the active region management techniques disclosed in co-pending U.S. patent application Ser. No. 10/ ______ (Atty. Docket No. 5181-89300) entitled “Active Region Management Techniques and Associated Methods of Designing and Manufacturing VLSI Circuits” and previously incorporated by reference. Once the next list of active segments and the next list of inactive segments of the span generally aligned with the next stop point have been generated at step 42 , the method proceeds to step 44 where the next list of active segments is compared to the current list of active segments and, based upon that comparison, one or more maximal component tiles may be identified for inclusion in the list of maximal component tiles. [0035] More specifically, for each active segment S in the current list of active segments, the next list of active segments is examined for a matching active segment S'. If there is no matching active segment S' in the next list of active segments, a maximal component tile having a width generally equal to the width [DX, DY] of the active segment S and a height generally equal to the difference between the level of the active segment S and the level of the active segment S' is generated. The generated maximal component tile is then inserted into the maximal component tile list CTL and the active segment S removed from the current list of active segments. After searching for a matching active segment S' in the next active segment list for each active segment S in the current active segment list, any unmatched active segment S' in the next active segment list is added to the current active segment list. Initially, the current active segment list will contain active segments at only one level. It should be noted, however, as the next active segment lists for various levels are examined, the current active segment list will likely contain active segments at plural levels. [0036] The method then proceeds to step 46 where the process of step 45 is repeated using the current and next list of inactive segments. By doing so, one or more maximal space tiles may be generated at step 44 and added to the maximal space tile list STL. Additionally, the current list of inactive segments will be modified by deleting the inactive segments, from the current list of inactive segments, the inactive segments having a matching inactive segment in the next list of inactive segments and by adding, to the current list of inactive segments, unmatched inactive segments from the next list of inactive segments. The method then returns to step 38 where the process described in steps 40 , 42 , 44 and 46 is repeated for each stop point in the set of stop points. After the last stop point in the set of stop points has been processed, the method will proceed from step 38 to step 48 where the maximal component tile list CTL and the maximal space tile list STL generated by the described method are output, typically, to the VLSI circuit design module 8 for use in connection with the design and manufacture of a VLSI circuit in accordance with the method of FIG. 2. [0037] The above-described method of generating a list of maximal component tiles CTL and a list of maximal space tiles STL for the routing area 90 shall again be described, now with respect to the example illustrated in FIGS. 4 and 5. As previously noted, FIG. 4 shows the CTs 92 , 94 and 96 positioned in the routing area 90 . As previously set forth, the process starts at step 32 by identifying the active and inactive segments for a span extending along the bottom edge 90 a of the routing area 90 . As there are no active segments along the bottom edge 90 a, the active and inactive segment lists for this span, which is generally aligned with the stop point SO, are initially set as follows: AL=Φ; and IL={[D 0 , D 9 , SO]}. [0038] At step 34 , the remaining members of the set of stop points are identified (S 1 , S 2 , S 3 , S 4 , S 5 , S 6 and S 8 ) and, at step 36 , an empty maximal component tile list CTL and an empty maximal space tile list STL are generated. As the stop points S 1 , S 2 , S 3 , S 4 , S 5 , S 6 and S 8 need to be examined, the method passes through 38 and on to step 40 where the stop point SI, the next stop point after the stop point S 0 , is selected for examination. As may be seen in FIG. 4, bottom edge 96 a of the CT 96 is generally aligned with the stop point S 1 . The corresponding segment is, therefore, considered to be active while the remaining segments generally aligned with the stop point S 1 are considered to be inactive. Accordingly, at step 42 , the next list of active segments and the next list of inactive segments are determined to be: AL=Φ; and IL={[D 0 , D 9 , SO]}. [0039] Proceeding to step 44 , the current active segment list is empty. As a result, there are no matches between the current list of active segments and the next list of active segments. As a result, no maximal component tiles are generated at step 44 . Furthermore, as the entry in the next active segment list is unmatched, it is added to the current active segment list, which now becomes: AL={[D 6 , D 8 , S 1 ]}. [0040] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains a single entry [D 0 , D 9 , S 0 ]. As there is no matching span in the next inactive segment list, a space tile, hereafter referred to as ST 100 and illustrated in FIG. 5, which extends from D 0 to D 9 in the D axis along a line generally aligned with S 0 and which extends from S 0 to S 1 in the S axis is generated and added to the maximal space tile list STL. The matched entry [D 0 , D 9 , S 0 ] is deleted from the current inactive segment list and the unmatched entries [D 0 , D 6 , S 1 ] and [D 8 , D 9 , S 1 ] of the next inactive segment list are added to the inactive segment list, thereby producing the following current inactive segment list: IL={[D 0 , D 6 , S 1 ], [D 8 , D 9 , S 1 ]}. [0041] The method then returns to step. 38 and, as there are additional stop points to be examined, on to step 40 where stop point S 2 is selected for examination. [0042] A span extending across the routing area 90 along a line generally aligned with the stop point S 2 passes along a lower edge 94 a of the CT 94 and through the interior of the CT 96 . Accordingly, the next list of active and inactive segments would be as follows AL={[D 3 , D 4 , S 2 ], [D 6 , D 8 , S 2 ]}; and IL={[D 0 , D 3 , S 2 ], [D 4 , D 6 , S 2 ], [D 8 , D 9 , S 2 ]}. [0043] For each active segment in the current active segment list, the next active segment list is searched for matches. Here, [D 6 , D 8 , S 1 ], currently the only entry in the current active segment, matches the [D 6 , D 8 , S 2 ] entry from the next active segment list. Accordingly, no maximal component tiles are generated during step 44 . The matched entry [D 6 , D 8 , S 2 ] is deleted from the next active segment list while the unmatched entry [D 3 , D 4 , S 2 ] from the next active segment list is added to the current active segment list, thereby producing the following current active segment list: AL={[D 3 , D 4 , S 2 ], [D 6 , D 8 , S 1 ]}. [0044] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains entries [D 0 , D 6 , S 1 ] and [D 8 , D 9 , S 1 ] while the next inactive segment list contains entries [D 0 , D 3 , S 2 ], [D 4 , D 6 , S 2 ] and [D 8 , D 9 , S 2 ]. Thus, the [D 8 , D 9 , S 1 ] entry of the current inactive segment list is matched while the [D 0 , D 6 , S 1 ] entry is unmatched. Accordingly, maximal space tile ST 102 , which extends from D 0 to D 6 in the D axis along a line generally aligned with SI, extends from S 1 to S 2 in the S axis and is illustrated in FIG. 5, is generated and added to the maximal space tile list STL. The unmatched entry is then deleted from the current inactive segment list while the unmatched entries [D 0 , D 3 , S 2 ] and [D 4 , D 6 , S 2 ] of the next inactive segment list is added to the current inactive segment list, thereby producing the following current inactive segment list: IL={[D 0 , D 3 , S 2 ], [D 4 , D 6 , S 2 ], [D 8 , D 9 , S 1 ]}. [0045] A span extending across the routing area 90 along a line generally aligned with the stop point S 3 passes through the interior of the CT 94 and along an upper edge 96 b of the CT 96 . Accordingly, the next list of active and inactive spans would be as follows: AL={[D 3 , D 4 , S 3 ]}; and IL ={[DO, D 3 , S 3 ], [D 4 , D 9 , S 3 ]}. [0046] For each active span in the current active segment list, the next active segment list is searched for matches. Here, the entry [D 3 , D 4 , S 2 ] matches the entry [D 3 , D 4 , S 3 ] while the entry [D 6 , D 8 , S 1 ] is unmatched. Accordingly, the entry [D 6 , D 8 , S 1 ] is used to generate a maximal component tile, hereafter referred to as CT 104 and illustrated in FIG. 5, which extends from D 6 to D 8 in the D axis along a line generally aligned with Si and from S 1 to S 3 in the S axis. The newly generated maximal component tile is then added to the maximal component tile list CTL. The unmatched entry [D 6 , D 8 , S 1 ] is deleted from the current active segment list and, since there are no unmatched entries from the next active segment list, the following current active segment list is produced: AL={[D 3 , D 4 , S 2 ]}. [0047] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains entries [D 0 , D 3 , S 2 ], [D 4 , D 6 , S 2 ] and [D 8 , D 9 , S 1 ] while the next inactive segment list contains entries [D 0 , D 3 , S 3 ] and [D 4 , D 9 , S 3 ]. Thus, the [D 4 , D 6 , S 2 ] and [D 8 , D 9 , S/I] entries of the current inactive segment list are unmatched while the [D 0 , D 3 , S 2 ] entry of the current inactive segment list is matched. Accordingly, the unmatched entry [D 4 , D 6 , S 2 ] is used to generate maximal space tile ST 106 , which extends from D 4 to D 6 in the D axis along a line generally aligned with S 2 , extends from S 2 to S 3 in the S axis and is illustrated in FIG. 5. Similarly, the unmatched entry [D 8 , D 9 , SI] is used to generate maximal space tile ST 108 , which extends from D 8 to D 9 in the D axis along a line generally aligned with S 2 , extends from S 1 to S 3 in the S axis and is illustrated in FIG. 5. The newly generated tiles are then added to the maximal space tile list, the unmatched entries [D 4 , D 6 , S 2 ] and [D 8 , D 9 , S 1 ] are deleted from the current inactive segment list and the unmatched entry [D 4 , D 9 , S 3 ] of the next inactive segment list is added to the current inactive segment list, thereby producing the following current inactive segment list: IL={[D 0 , D 3 , S 2 ], [D 4 , D 9 , S 3 ]}. [0048] The method then returns to step 38 and, as there are additional stop points to be examined, on to step 40 where stop point S 4 is selected for examination. [0049] A span extending across the routing area 90 along a line generally aligned with the stop point S 4 along a lower edge 92 a of the CT 92 and through the interior of the CT 94 . Accordingly, the next list of active and inactive spans generated at step 42 would be as follows: AL={[D 1 , D 2 , S 4 ], [D 3 , D 4 , S 4 ]}; and IL {[DO, D 1 , S 4 ], [D 2 , D 3 , S 4 ], [D 4 , D 9 , S 4 ]}. [0050] The current and next active segment lists are then processed at step 44 . The current active segment list is [D 3 , D 4 , S 2 ] while the next active segment list is [D 1 , D 2 , S 4 ], [D 3 , D 4 , S 4 ]. Thus, [D 3 , D 4 , S 2 ], the only member of the current active segment list, matches [D 3 , D 4 , S 4 ] of the next active segment list while [D 1 , D 2 , S 4 ] of the next active segment lists is unmatched. Accordingly, at step 44 , no maximal component tiles are generated and no entries are deleted while [D 1 , D 2 , S 4 ] is added to the current active segment list, thereby producing the following current active segment list: AL={[D, D 2 , S 4 ], [D 3 , D 4 , S 2 ]}. [0051] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains entries [D 0 , D 3 , S 2 ] and [D 4 , D 9 , S 3 ] while the next inactive segment list contains entries [D 0 , D 1 , S 4 ], [D 2 , D 3 , S 4 ] and [D 4 , D 9 , S 4 ]. Thus, the [D 4 , D 9 , S 3 ] entry of the current inactive segment list is matched to the entry [D 4 , D 9 , S 4 ] entry of the next inactive segment list while the [D 0 , D 3 , S 2 ] entry of the current inactive segment list and the [D 0 , D 1 , S 4 ] and [D 2 , D 3 , S 4 ] entries of the next inactive segment list are unmatched. Accordingly, the unmatched entry [D 0 , D 3 , S 2 ] of the current active span is used to generate maximal space tile ST 110 , which extends from D 0 to D 3 in the D axis along a line generally aligned with S 2 , extends from S 2 to S 4 in the S axis and is illustrated in FIG. 5. The newly generated space tile is then added to the maximal space tile list STL, the unmatched entry [D 0 , D 3 , S 2 ] is deleted from the current inactive segment list and the unmatched entries [D 0 , D 1 , S 4 ] and [D 2 , D 3 , S 4 ] of the next inactive segment list is added to the current inactive segment list, thereby producing the following current inactive segment list: IL={[D 0 , D 1 , S 4 ], [D 2 , D 3 , S 4 ], [D 4 , D 9 , S 3 ]}. [0052] The method then returns to step 38 and, as there are additional stop points to be examined, on to step 40 where stop point S 5 is selected for examination. [0053] A span extending across the routing area 90 along a line generally aligned with the stop point S 5 passes through the interior of the CT 92 and along the upper edge 94 b of the CT 94 . Accordingly, the next list of active and inactive spans generated at step 42 would be as follows: AL={[D, D 2 , S 5 ]; }and IL={[D 0 , D 1 , S 5 ], [D 2 , D 9 , S 5 ]}. [0054] The current and next active segment lists are then processed at step 44 . The current active segment list is [D 1 , D 2 , S 4 ] and [D 3 , D 4 , S 2 ] while the next active segment list is [D 1 , D 2 , S 5 ]. Thus, the [D 1 , D 2 , S 4 ] entry of the current active segment list matches the [D 1 , D 2 , S 5 ] entry of the next active segment list while the [D 3 , D 4 , S 2 ] entry of the current active segment list is unmatched. Accordingly, the [D 3 , D 4 , S 2 ] of the current active segment list is used to generate a maximal component tile, hereafter referred to as CT 112 , which extends from D 3 to D 5 in the D axis along a line generally aligned with the stop point S 4 and from the stop point S 2 to the stop point S 5 in the S axis, and is illustrated in FIG. 5. The newly generated maximal component tile is then added to the maximal component tile list CTL. The unmatched entry [D 3 , D 4 , S 2 ] is then deleted from the current active segment list and the matched entry [D 1 , D 2 , S 5 ] is deleted from the next active segment list, thereby resulting in the following current active segment list: AL={[D 1 , D 2 , S 4 ]}. [0055] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains entries [D 0 , D 1 , S 4 ], [D 2 , D 3 , S 4 ] and [D 4 , D 9 , S 3 ] while the next inactive segment list contains the entries [D 0 , D 1 , S 5 ] and [D 2 , D 9 , S 5 ]. Thus, the [D 2 , D 3 , S 4 ], [D 4 , D 9 , S 3 ] entries of the current inactive segment list and the [D 2 , D 9 , S 5 ] entry of the next inactive segment list are unmatched. Accordingly, the unmatched entry [D 2 , D 3 , S 4 ] of the current inactive span is used to generate maximal space tile ST 114 , which extends from D 2 to D 3 in the D axis along a line generally aligned with S 4 and which extends from S 4 to S 5 in the S axis while the unmatched entry [D 4 , D 9 , S 3 ] of the current inactive span is used to generate maximal space tile ST 116 which extends from D 4 to D 9 in the D axis along a line generally aligned with S 3 and which extends from S 3 to S 5 in the S axis. The newly generated space tiles ST 114 and ST 116 , both of which are illustrated in FIG. 5, are then added to the maximal space tile list STL, the unmatched entries [D 2 , D 3 , S 4 ] and [D 4 , D 9 , S 3 ] are deleted from the current inactive segment list and the unmatched entry [D 2 , D 9 , S 5 ] of the next inactive segment list is added to the current inactive segment list, thereby producing the following current inactive segment list: IL={[D 0 , D 1 , S 4 ], [D 2 , D 9 , S 5 ]}. [0056] The method then returns to step 38 and, as there are additional stop points to be examined, on to step 40 where the stop point S 6 is selected for examination. [0057] A span extending across the routing area 90 along a line generally aligned with the stop point S 6 passes along the upper edge 92 b of the CT 92 . Accordingly, the next list of active and inactive spans generated at step 42 would be as follows: ALΦ; and IL={[D 0 , D 9 , S 6 ]}. [0058] The current and next active segment lists are then processed at step 44 . The current active segment list is [D 1 , D 2 , S 4 ] while the next active segment list is empty. Thus, the [D 1 , D 2 , S 4 ] entry of the current active segment list is unmatched. Accordingly, the [D 1 , D 2 , S 4 ] of the current active segment list is used to generate a maximal component tile, hereafter referred to as CT 118 , which extends from D 1 to D 2 in the D axis along a line generally aligned with the stop point S 4 and from the stop point S 4 to the stop point S 6 in the S axis, and is illustrated in FIG. 5. The newly generated maximal component tile is then added to the maximal component tile list CTL. The unmatched entry [D 1 , D 2 , S 4 ] is then deleted from the current active segment list, thereby emptying the current active segment list and, since the next active segment list is empty as well, the current active segment list becomes the following: AL=Φ. [0059] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains entries [D 0 , D 1 , S 4 ] and [D 2 , D 9 , S 5 ] while the next inactive segment list contains the entry [D 0 , D 9 , S 6 ]. Thus, the [D 0 , D 1 , S 4 ] and [D 2 , D 9 , S 5 ] entries of the current inactive segment list and the [D 0 , D 9 , S 6 ] entry of the next inactive segment list are unmatched. Accordingly, the unmatched entry [D 0 , D 1 , S 4 ] of the current inactive span is used to generate maximal space tile ST 120 , which extends from D 0 to D 1 in the D axis along a line generally aligned with S 4 and which extends from S 4 to S 6 in the S axis while the unmatched entry [D 2 , D 9 , S 5 ] of the current inactive span is used to generate maximal space tile ST 122 which extends from D 2 to D 9 in the D axis along a line generally aligned with S 5 and which extends from S 5 to S 6 in the S axis. The newly generated space tiles ST 120 and ST 122 , both of which are illustrated in FIG. 5, are then added to the maximal space tile list STL, the unmatched entries [D 0 , D 1 , S 4 ] and [D 2 , D 9 , S 5 ] are deleted from the current inactive segment list and the unmatched entry [D 0 , D 9 , S 6 ] of the next inactive segment list is added to the current inactive segment list, thereby producing the following current inactive segment list: IL={[D 0 , D 9 , S 6 ]}. [0060] The method then returns to step 38 and, as there are additional stop points to be examined, on to step 40 where the stop point S 8 is selected for examination. The stop point S 8 is generally aligned with an upper edge 90 b of the routing area 90 . As neither a lower edge nor an interior of a component is positioned along the upper edge 90 b , the next list of active and inactive spans generated at step 42 would be as follows: AL=Φ; and IL={ [D 0 , D 9 , S 7 ]}. [0061] The current and next active segment lists are then processed at step 44 . The current active segment list is Φ while the next active segment list is Φ. As both the current and next active segment lists are empty, no additional maximal component tiles are generated and the current active segment list remains empty. [0062] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains the entry [D 0 , D 9 , S 6 ] while the next inactive segment list contains the entry [D 0 , D 9 , S 8 ]. While the current and inactive segment lists contain matching entries, the stop point being examined is the last stop point in the set of stop points. Accordingly, the [D 0 , D 9 , S 6 ] entry of the current inactive segment list is used to generate a maximal space tile, hereafter referred to as maximal space tile 124 , which extends from D 0 to D 9 in the D axis along a line generally aligned with S 6 , extends from S 6 to S 8 in the S axis and is illustrated in FIG. 5. The newly generated space tile is added to the maximal space tile list STL and the entry [D 0 , D 9 , S 6 ] of the current inactive segment list is deleted therefrom, thereby emptying it. Further, as the entry [D 0 , D 9 , S 8 ] was matched to the entry [D 0 , D 9 , S 6 ], it is not added to the current inactive segment list, thereby keeping the current inactive segment list empty. The method then returns to step 38 and as all of the stop points SO through S 6 and S 8 have been examined, to step 48 for output of the generated maximal component tile and maximal space tile lists CTL and STL to the VLSI circuit design module 6 . The method then ends at step 50 . [0063] Continuing to refer to FIG. 3 a , the method of generating a list of maximal component tiles CTL and a list of maximal space tiles STL for the routing area 90 ′, shall now be described, this time, in conjunction with FIGS. 4 and 6. As previously noted, FIG. 4 shows the CT 98 positioned in the routing area 90 ′. As before, the process starts at step 32 by identifying the active and inactive segments for a span extending along a bottom edge 90 a ′ of the routing area 90 ′. As there are no active segments along the bottom edge 90 a ′, the active and inactive segment lists for this span, which is generally aligned with the stop point SO, are initially set as follows: AL=Φ; and IL={[D 0 , D 9 , SO]}. [0064] At step 34 , the remaining members of the set of stop points are identified (S 5 and S 7 ) and, at step 36 , an empty maximal component tile list CTL and an empty maximal space tile list STL are generated. As the stop points S 5 , S 7 and S 8 need to be examined, the method passes through 38 and on to step 40 where the stop point S 5 , the next stop point after the stop point SO, is selected for examination. As may be seen in FIG. 4, bottom edge 98 a of the CT 98 is generally aligned with the stop point S 5 . The corresponding segment is, therefore, considered to be active while the remaining segments generally aligned with the stop point S 5 are considered to be inactive. Accordingly, at step 42 , the next list of active segments and the next list of inactive segments are determined to be: AL={[D 5 , D 7 , S 5 ]}; and IL={[D 0 , D 5 , S 5 ], [D 8 , D 9 , S 5 ]}. [0065] Proceeding to step 44 , the current active segment list is empty. As a result, there are no matches between the current list of active segments and the next list of active segments. As a result, no maximal component tiles are generated at step 44 . Furthermore, as the entry in the next active segment list is unmatched, it is added to the current active segment list, which now becomes: AL={[D 5 ,D 7 ,S 5 ]}. [0066] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains a single entry [D 0 , D 9 , SO]. As there is no matching span in the next inactive segment list, a space tile, hereafter referred to as ST 200 and illustrated in FIG. 6, which extends from D 0 to D 9 in the D axis along a line generally aligned with S 0 and which extends from S 0 to S 5 in the S axis is generated and added to the maximal space tile list STL. The matched entry [D 0 , D 9 , S 0 ] is deleted from the current inactive segment list and the unmatched entries [D 0 , D 5 , S 5 ] and [D 8 , D 9 , S 5 ] of the next inactive segment list are added to the inactive segment list, thereby producing the following current inactive segment list: IL={[D 0 , D 5 , S 5 ], [D 8 , D 9 , S 5 ]}. [0067] The method then returns to step 38 and, as there are additional stop points to be examined, on to step 40 where stop point S 7 is selected for examination. [0068] A span extending across the routing area 90 ′ along a line generally aligned with the stop point S 7 passes along an upper edge 98 b of the CT 98 . Accordingly, the next list of active and inactive segments would be as follows AL=Φ; and IL={[D 0 , D 9 , SO]}. [0069] For each active segment in the current active segment list, the next active segment list is searched for matches. Here, [D 5 , D 7 , S 5 ], currently the only entry in the current active segment, is unmatched. Accordingly, the entry [D 5 , D 7 , S 5 ] is used to generate a maximal component tile, hereafter referred to as CT 202 and illustrated in FIG. 6, which extends from D 5 to D 7 in the D axis along a line generally aligned with S 5 and from S 5 to S 7 in the S axis. The newly generated maximal component tile is then added to the maximal component tile list CTL. The unmatched entry [D 5 , D 7 , S 5 ] is deleted from the current active segment list, thereby emptying it, and, since there are no unmatched entries from the next active segment list, the current active segment list remains empty as shown below: AL=Φ. [0070] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains entries [D 0 , D 5 , S 5 ] and [D 7 , D 9 , S 5 ] while the next inactive segment list contains the entry [D 0 , D 9 , S 7 ]. Thus, the [D 0 , D 5 , S 5 ] and [D 7 , D 9 , S 5 ] entries of the current inactive segment list are unmatched. Accordingly, the unmatched entry [D 0 , D 5 , S 5 ] is used to generate maximal space tile ST 204 , which extends from D 0 to D 5 in the D axis along a line generally aligned with S 5 , extends from S 5 to S 7 in the S axis and is illustrated in FIG. 5. Similarly, the unmatched entry [D 7 , D 9 , S 5 ] is used to generate maximal space tile ST 206 , which extends from D 7 to D 9 in the D axis along a line generally aligned with S 5 , extends from S 5 to S 7 in the S axis and is illustrated in FIG. 5. The newly generated tiles are then added to the maximal space tile list, the unmatched entries [D 0 , D 5 , S 5 ] and [D 7 , D 9 , S 5 ] are deleted from the current inactive segment list and the unmatched entry [D 0 , D 9 , S 7 ] of the next inactive segment list is added to the current inactive segment list, thereby producing the following current inactive segment list: IL{[D 0 , D 9 , S 7 ]}. [0071] The method then returns to step 38 and, as there are additional stop points to be examined, on to step 40 where stop point S 8 is selected for examination. The stop point S 8 is generally aligned with an upper edge 90 b ′ of the routing area 90 ′. As neither a lower edge nor an interior of a component is positioned along the upper edge 90 b ′, the next list of active and inactive spans generated at step 42 would be as follows: AL=Φ; and IL={[D 0 , D 9 , SO]}. [0072] The current and next active segment lists are then processed at step 44 . The current active segment list is Φ while the next active segment list is Φ. As both the current and next active segment lists are empty, no additional maximal component tiles are generated and the current active segment list remains empty. [0073] The method then proceeds to step 46 for processing of the current inactive segment list. The current inactive segment list contains the entry [D 0 , D 9 , S 7 ] while the next inactive segment list contains the entry [D 0 , D 9 , S 8 ]. While the current and inactive segment lists contain matching entries, the stop point being examined is the last stop point in the set of stop points. Accordingly, the [D 0 , D 9 , S 7 ] entry of the current inactive segment list is used to generate a maximal space tile, hereafter referred to as maximal space tile 208 , which extends from D 0 to D 9 in the D axis along a line generally aligned with S 7 , extends from S 7 to S 8 in the S axis and is illustrated in FIG. 5. The newly generated space tile is added to the maximal space tile list STL and the entry [D 0 , D 9 , S 7 ] of the current inactive segment list is deleted therefrom, thereby emptying it. Further, as the entry [D 0 , D 9 , S 8 ] was matched to the entry [D 0 , D 9 , S 7 ], it is not added to the current inactive segment list, thereby keeping the current inactive segment list empty. The method then returns to step 38 and as all of the stop points S 0 , S 5 , S 7 and S 8 have been examined, to step 48 for output of the generated maximal component tile and maximal space tile lists CTL and STL to the VLSI circuit design module 6 . The method then ends at step 50 . [0074] Referring next to FIGS. 3 b - 1 through 3 b - 2 , the method of determining an optimal tile path and minimum cost wire path between pins that are CTs to be connected will now be described in greater detail. From the application of the method of FIG. 3a to the routing areas illustrated in FIG. 4, it has been determined that the CTs 118 , 104 and 202 are pins to be connected while the CT 112 is an obstruction to be avoided. The method commences at step 50 and, at step 52 , a starting tile S and a destination tile T are selected from amongst the CTs 118 , 104 and 202 . The method then proceeds on to step 54 where a priority queue Q is created and to step 56 where the starting tile S is inserted into the priority queue Q. The method then continues on to step 58 , where a search tree ST having the starting tile S as its root is generated and on to step 60 where an initial path cost C between starting tile S and destination tile T is set to infinity. [0075] Proceeding on to step 62 , while the priority queue Q is not empty, steps 64 through 84 are executed as appropriate. Accordingly, the method either proceeds to step 64 or to step 86 described below. Here, as the priority queue Q currently holds the starting tile S, the method proceeds on to step 64 where the lowest cost tile E is popped from the priority queue Q. To appreciate which tile is the lowest cost tile E to be popped from the priority queue Q, a brief illustration shall be necessary. Assume, for example, that the CT 118 is selected as the starting tile S and the CT 104 is selected as the destination tile T. There are seven tiles E, specifically, the tiles ST 120 , ST 124 , ST 122 , ST 114 , ST 110 , ST 200 and ST 204 , that adjoin the tile CT 118 . The distance from each tile E to the destination tile T is evaluated and the tile E closest to the destination tile T is popped from the priority queue as the lowest cost tile E. In the foregoing example, of the seven tiles E, the ST 200 is the only tile adjoining the destination tile CT 104 . Thus, as the tile ST 200 is closest to the destination tile CT 104 , the tile ST 200 is popped at step 64 as the lowest cost tile E. [0076] Proceeding on to step 66 , if the tile E popped from the priority queue is the destination tile T, steps 68 , 70 and 72 are executed. Otherwise, the method proceeds to step 74 , below. More specifically at step 68 , a tile path LP from the starting tile S to the destination tile T is retrieved from the search tree TS. At step 70 , the minimum cost C 2 from the starting tile S to the destination tile T is evaluated and, at step 72 , if the current cost C exceeds the evaluated minimum cost C 2 , then C is set to C 2 and the minimum cost point path is saved. [0077] Proceeding on to step 74 for each tile F neighboring the tile E, steps 76 through 84 are executed to expand the search tree. At step 76 , a minimum cost CF from the starting tile T to the tile F is evaluated and, at step 78 , a lower cost bound CT from the tile F to the destination tile T is evaluated. At step 80 , an estimated cost CE is set as the sum of CF and CT and, at step 82 if CE is greater than or equal to the current cost C, then the method continues and the search tree TS is pruned. Otherwise, as set forth in step 84 , the tile F is inserted into the priority queue Q with the estimated cost CE and the tile F is inserted into the tree TS as a child of the tile E. The method then proceeds to step 86 where, the saved minimum cost (if determined) is returned. Otherwise a routing failure is reported. The method then ends at step 88 . [0078] The input to the above-referenced algorithm is the list of space tiles created by the method of FIG. 3 a , a start tile S and a destination tile T. The output is the list of points for the minimum cost routing path. We maintain a priority queue Q and a search tree TS, where Q is initially set to S and S is set to the root of the search tree TS. When no point path has been found, the path cost is set to infinity. As illustrated herein, the search terminates only when the priority queue Q is empty. In every search, one tile E is popped from the priority queue Q. If the tile E is the destination tile T, then the minimum cost path from the root of the search tree to the destination tile T is evaluated and the cost compared with saved cost. An update is performed if a lower cost path is found and the corresponding path is saved. Steps 66 through 72 perform this task. Steps 74 through 84 expand the search and prune the branch. Process the neighbor tiles F of the tile E one by one. For each such tile F, CF, the minimum cost from S to F and CT, the lower bound cost to T are evaluated. The cost from S to T through this path cannot be lower than estimated CE=CF+CT. If this estimated cost is higher than the current cost C, then prune this search path; otherwise expand the search by adding tile F into tree TS as a child node of E. [0079] Thus, there has been described and illustrated herein, various methods suitable for use in conjunction with the design and manufacture of VLSI circuits. However, those skilled in the art should recognize that numerous modifications and variations may be made in the techniques disclosed herein without departing substantially from the spirit and scope thereof, which is defined solely by the claims appended hereto.

Disclosed herein is a method and associated apparatus for the design and manufacture of VLSI circuit which incorporates therein a method for routing connections between component tiles of the VLSI circuit being designed.

BACKGROUND OF THE INVENTION The present invention relates to an image reading device used in a facsimile device, copier, or the like. Conventionally, a facsimile device includes an image reading device for reading an image printed on an original. An "original" is an original document, drawing, or other sheet bearing an image to be read. The image is transmitted to another facsimile device via a modem, a network control unit (NCU), and a telephone line. A feeding device in the image reading device feeds an original, a light source illuminates the original, and an image sensor (such as a CCD) reads the reflected light. In order to provide a threshold for discriminating an image pattern from the background (usually white), the image reading device often includes a white level reference member facing the image sensor across the feed path of the originals. The white level reference member is readable when no original is present in the feed path. After the facsimile device is turned on, the image sensor reads the white surface of the white level reference member and the threshold (white level) is stored. In many facsimile devices and copiers, a movable cover is provided for covering the image reading device, and the cover can be opened for removing jammed paper. However, when the cover is not fully closed, external or ambient light may enter the interior of the facsimile device. If the external light reaches the image sensor while the image sensor is reading the white level reference member, the threshold setting may become faulty. To avoid this situation, the image reading device may incorporate a sensor (such as a limit switch) for detecting when the movable cover is fully closed. The use of such a sensor increases the cost of the device. Alternatively, the threshold can be determined at the factory and stored in an EEPROM-type memory (or other non-volatile memory). However, since the threshold data can be several hundred bytes, a relatively large EEPROM is necessary to store the threshold data, also increasing the cost. The same problem exists in a copier, an image scanner or a digitizer. SUMMARY OF THE INVENTION In order to meet this object, according to one aspect of the present invention, an image reading device includes: an image sensor for reading images from an original; a white level reference member, facing the image sensor and readable by the image sensor to set a white level threshold of the image sensor; and at least one marking formed on the white level reference member; a movable cover associated with the white level reference member; and control means for checking if the image sensor reads the at least one marking to determine a status of the movable cover based on the checking. In this manner, no special sensor is required to sense the status of the movable cover, as the marking is used to determine the status. Preferably, the control means includes means for initiating the checking in response to power being supplied to the controller. In this case, the checking is performed every time the facsimile device or other device housing the image reading device is turned on. In one particular development of this aspect of the invention, the image reading device further includes: a memory for storing the white level threshold, the control means storing the white level threshold in the memory only after the image sensor detects the marking. The white level reference member is preferably mounted to the movable cover, so that the markings are not sensed when the cover is moved away from the image sensor. The device may include display means, and wherein the controller controls the display means to indicate the status of the movable cover. According to another aspect of the present invention, an image reading device, includes: an image sensor for reading images from an original; a white level reference member, facing the image sensor and readable by the image sensor to set a white level threshold of the image sensor; and at least one marking defining a reading range of the image sensor, the at least one marking being formed on the white level reference member facing the image sensor; a movable cover associated with the white level reference member; and control means for checking if the image sensor reads the at least one marking to determine a status of the movable cover based on the checking. In this manner, no special sensor is required to sense the status of the movable cover, as the marking provided for the purpose of determining a reading range of the image sensor is used to determine the status. In one particular development, the marking or markings are a pair of parallel markings spaced by a predetermined distance on the reference surface. These marking lines are used to define the center position and width of the reading range. In another particular development, the movable cover is swingably supported to open and close. The white level reference member is swung away from the image sensor to a first position where the white level reference member is unreadable by the image sensor when the movable cover is in an open status, and to a second position where the white level reference member is readable by the image sensor when the movable cover is in a closed status. In this case, the control means preferably controls the image sensor to set the white level threshold only when the control means verifies a status of the movable cover to be a closed status where the white level reference member is readable by the image sensor. In still another aspect of the invention, an image reading device includes: a lower guide plate having an opening formed therein; an upper member, swingable toward and away from the lower guide plate; a line image sensor attached to the lower guide plate, the line image sensor positioned to read images through the opening; a white level reference member attached to the upper member in a position readable by the line image sensor only when the white level reference member is swung toward the lower guide plate, the white level reference member defining a white level threshold of the image sensor when the image sensor reads the white level reference member; a pair of markings on the white level reference member in a position readable by the line image sensor only when the white level reference member is swung toward the lower guide plate, the pair of markings being separated from each other by a predetermined distance; and a controller includes: means for checking a position of the upper member based on a reading of the pair of markings by the line image sensor, means for setting a reading range of the line image sensor based on a reading of the predetermined distance from the pair of markings by the line image sensor; and means for setting a white level threshold of the image sensor based on a reading of the white level reference member by the line image sensor. In this manner, the controller carries out three functions based upon the reading of the reference surface: setting of reading range, setting of white level threshold, and checking the upper member position. Since the upper member is preferably provided to a swingable cover, the controller determines the position of the swingable cover depending on the means for checking a position of the upper member. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a facsimile device employing an embodiment of an image reading device according to the invention; FIG. 2 is a schematic side view of the facsimile of FIG. 1; FIG. 3 is a perspective view of an original reading portion of the facsimile device of FIG. 1; FIG. 4 is a schematic bottom view of a white level reference member of the original reading portion of FIG. 3; FIG. 5 is a block diagram of a control system of the image reading device; and FIG. 6 is a flow chart showing an initializing operation of the image reading device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view of a facsimile device 1 to which the embodiment of the invention is applied, and FIG. 2 is a schematic side view of the facsimile device 1. As shown in FIG. 1, the body of the facsimile device includes a lower cover 2 and an upper cover 3. A handset 4 is provided at one side of the lower cover 2. A recording sheet cassette 6 is attachable to and detachable from the lower case 2. An original holder 18 accepts originals to be read. A movable cover 19, having an operation panel 42 with a display 42a, is rotatably supported on the upper cover 3. As shown in FIG. 2, a number of recording sheets 5 are stacked in the recording sheet cassette 6. A single recording sheet 5 is fed by a sheet feeding roller 7 from the stack to a pair of intermediate feeding rollers 8, which feed the sheet 5 to a printing unit 11 including a thermal line printing head 9 and a platen roller 10. When the recording sheet 5 reaches the printing unit 11, the intermediate feeding rollers 8 wait until the facsimile device 1 receives image data from another facsimile device, and then feed the recording sheet 5 in tandem with the platen roller 10. When the facsimile device 1 receives the image data, the image is reproduced on the waiting recording paper 5 via an ink sheet 14 (fed from a feeding reel 12 and wound by a winding reel 13). The recording sheet 5 on which the image is formed is discharged through a recording sheet discharge slot 16 by a pair of discharge rollers 15. One or more originals 17 are placed on the original holder 18, inclined downward to the front side of the facsimile device 1. The movable cover 19 is swingably supported about a shaft 19a provided to the front side of the upper cover 3. The original 17 placed on the original holder 18 is fed by a separating roller 20 (if more than one original, it is separated from the remaining originals) and a pair of feeding rollers 21 through an original reading portion and discharged through an original discharge slot 24. The original reading portion is shown in detail in FIGS. 3 and 4. As shown in FIG. 3, the original 17 is fed between an upper guide plate 27 and a lower guide plate 26 in the original reading portion to a CCD scanner 22. The CCD scanner 22 is provided to the lower guide plate 26. The lower guide plate 26 has an opening (elongated in the direction of original width) through which a detecting surface of the CCD scanner 22 can face the upper guide plate 27. The original reading portion includes an original detecting switch 25 provided upstream of the CCD scanner 22 for reading an image. The original detecting sensor 25 can be a contact type sensor, such as a micro limit switch, or a non-contact type sensor, such as a photosensor. The original detecting sensor 25 is provided upstream of the CCD scanner 22 by a distance L 1 . A white level reference member 28 having the same length as the detecting surface of the CCD scanner 22 is attached to the upper guide plate 27. As shown in FIG. 4, a pair of black lines 28a, 28a are formed having an interval H1 in the width direction of the original 17 (i.e., the scanning direction of the CCD 22). The interval H1 is provided for setting the reading range of the original in the direction of the original width. That is, a CPU 30 (described later) sets the center position of the reading range according to the center position of the black lines 28a--28a as readby the CCD 22. FIG. 5 is a block diagram showing a control system 29 of the facsimile device. A CPU 30 is connected (via a bus 37) to a power switch 34, a ROM 31 storing a control program, a readable and writable non-volatile memory (EEPROM) 32, a RAM 33, the CCD scanner 22, the original detecting sensor 25, the printing unit 11, and driving circuit 36 for driving a stepping motor 35 which drives the feeding rollers 21. The EEPROM 32 has a quick-dial number storing area, an originator's number storing area, a communication condition storing area, and a function storing area (including communication mode, program and function data). The RAM 33 has a communication managing information storing area for storing communication information such as the date and time of a communication. The CPU 30 is also connected by the bus 37 (via unillustrated connections) to the operation panel 42 for entering data such a facsimile number, the LCD display 42a of the operation panel 42, and the handset 4. The CPU is further connected to unillustrated elements well known in the art: a network control unit (NCU) for controlling a network via an external telephone exchange, a modem, a buffer memory for temporarily storing the coded image data, a coding circuit for coding the image data to be transmitted, a decoding circuit for decoding the image data received, and an image memory for storing the received data a clock circuit for a calendar function such as date and time, and a character generating portion for displaying characters on the LCD display 42a and for generating characters according to the character code for printing by the printing unit 11. An initializing operation of the facsimile device 1 is shown in the flowchart of FIG. 6. As shown in FIG. 6, when the power switch 34 is turned ON (step S1), the CCD scanner 22 is driven and begins scanning in step S2. In step S3, the CPU 30 evaluates the result of the CCD scan, and checks if the black lines 28a, 28a on the white level reference member 28 can be recognized in the line image data at step S3. If the CPU 30 does not recognize the black lines 28a, 28a in the line image data (N at step S3), the CPU 30 illuminates an LED lamp (not shown) provided on the operation panel 42, displays "COVER OPEN" in the LCD display 42a, then returns to step S2. That is, the CPU 30 recognizes that the cover is open if the black lines 28a, 28a, are not detected. If the CPU 30 recognizes the black lines 28a, 28a in the line image data (Y at step S3), it proceeds to step S5. In step S5, "COVER OPEN" in the display is erased. Naturally, if "COVER OPEN" was never displayed, step S5 has no effect. The CPU 30 will only proceed to step S5 if the cover 19 is sufficiently, i.e., completely, closed. The process then proceeds to step S6. In step S6, the CPU 30 reads the white reference surface, and continues to step S7, where the threshold data from reading the white level reference member 28 is stored in the RAM 33. In this manner, when the facsimile device 1 is turned on, the CPU 20 uses the image signal from the CCD 22 to detect whether or not the cover 19 is fully closed. Consequently, the facsimile device 1 does not need an independent sensor for detecting whether the cover 19 is fully closed or not. Furthermore, the threshold is renewed every time the facsimile device is turned on, and a large EEPROM or other non-volatile memory for storing threshold data is not needed. Furthermore, by fixing the upper guide plate 27 to the cover 19, the gap between the guide plates 26 and 27 becomes larger when the cover 19 is opened. Therefore, the operation for removing the original may become easier. Still further, by providing the white level reference member 28 to the surface of the upper guide plate 27, the operation for cleaning or replacement of the white level reference member 28 may be easier. The present disclosure relates to subject matter contained in Japanese Patent Application No. HEI 07-135110, filed on Jun. 1, 1995, which is expressly incorporated hereinby reference in its entirety.

A reference surface for determining a threshold level of an image sensor is provided on a guide plate swingable with a cover away from the image sensor. The reference surface has markings thereon for determining a reading range of the image sensor. The image reading device makes three detections from the reading of the reference surface: a detection of the cover position by detecting the presence of the markings; a detection of the reading range of the image sensor by detecting the arrangement of the markings; and a detection of the threshold level of the image sensor by detecting the background of the reference surface. The threshold level is not taken until the device has determined that the cover is closed.

TECHNICAL FIELD [0001] The invention pertains to a device to support cardiac function. In particular, the device according to the invention serves to support a pumping function of a heart. BACKGROUND [0002] Due to illness, the pumping function of a heart can be reduced, which is also called cardiac insufficiency. Cardiac insufficiency is from the medical as well as from the economical standpoint of great and increasing importance. In the second decade of this century, 23 million people worldwide will suffer from cardiac insufficiency; the annual rate of new cases will be about 2 million people. In the US alone, 5 million people are currently suffering from cardiac insufficiency. Here, the annual rate of new cases is approximately 550,000 people. Already in this decade, the number of incidences in people over 50 years of age will double to more than 10 million. The same applies to the European continent. [0003] Causes for cardiac insufficiency can be impaired contractility or reduced filling of the cardiac chambers due to damage to the myocardium. Hypertension can lead to an increased pumping resistance, which can also negatively affect the pumping function of the heart. The pumping function of a heart can also be reduced by leaking valves (e.g., a leaking aortic valve or mitral valve). Impairments of the cardiac conduction system generate arrhythmias, which can also lead to a reduced pumping function of the heart. If the movement of the heart is restricted from the outside, e.g., due to an accumulation of fluid in the pericardium, this can result in a reduced pumping function as well. Cardiac insufficiency often leads to shortness of breath (especially in the case of left ventricular insufficiency), or to water retention in the lungs or in the abdomen (in particular in the case of right ventricular insufficiency). [0004] Different types of cardiac insufficiencies are treatable with medication or surgery. In some cases of arrhythmias, normal cardiac rhythm can be restored with a pacemaker. A leaking valve can be replaced surgically with a cardiac valvular prosthesis. A reduced pumping function can be assisted by an implanted heart pump. A treatment approach addressing the various causes of heart insufficiency is to assist the pumping function of the heart by means of an implant, which exerts mechanical pressure onto the heart and therefore improves its pumping performance. [0005] Some known mechanical ventricular assist devices have been disclosed in U.S. Pat. No. 5,749,839 B1 and U.S. Pat. No. 6,626,821 B1, and in WO application 00/25842. These documents disclose mechanical ventricular assist devices that require open-chest surgery. Many cardiac assist systems are complex and can only be implanted by means of an elaborate surgical procedure. All cardiac assist systems are integrated into the blood circulation of the patients. Improved centrifugal or magnetically supported impeller systems carry blood continuously. The contact of the blood with the surface of the implanted systems poses a great engineering and medical challenge. Common complications of cardiac assist systems are strokes, hemorrhage and septicemia. They often lead to long-term hospitalization and frequent re-admissions of patients already released from the hospital. SUMMARY [0006] Various aspects of the invention feature the device for the support of the cardiac function includes a sheath configured to transition from a non-expanded state into an expanded state, with the sheath being self-expanding and being configured to be inserted into a delivery system, and which in the expanded state can at least partially enclose a heart. One potential advantage of the device is that it may be implanted using minimally invasive procedures. [0007] In some implementations, the sheath can be made of a wire mesh, which can have diamond-shaped cells. Preferably, the mesh is made of a shape memory alloy. The crossing points of the wires of the wire mesh can be permanently attached to each other, thus increasing the stability of the sheath. The crossing points may also be separable, which increases the flexibility of the sheath and thereby can make the sheath easier to compress. Or some of the crossing points may be permanently interconnected while other crossing points are not permanently interconnected. By selecting suitable crossing points to be permanently interconnected, and crossing points that are not permanently interconnected, the stability and flexibility of the sheath can be adjusted. [0008] According to one aspect of the invention, the sheath can also consist of a lattice structure, with the lattice structure consisting of links, and multiple links defining one cell. The lattice structure exhibits a diamond-shaped lattice structure. The links and the intersections of the links exhibit enforcements in order to increase the stability of the sheath. The effect of the enforcements is similar to the effect of the interconnected crossing points in embodiments of the sheath in the form of a wire mesh. The links and the intersections can also be made of a thinner or weaker material in order to increase the flexibility of the sheath. The effect of a thinner or weaker material at intersections is similar to the effect of the non-interconnected intersections in embodiments of the sheath in the form of a wire mesh. [0009] The sheath can also be made of a solid material, from which parts have been removed. For example, the sheath can be made of a tube or an individually shaped sheath sleeve, into which holes have been formed or cut. The holes can be formed such that the sheath exhibits increased stability in some areas, and increased flexibility in other areas. [0010] Generally, areas of increased stability are desired in situations, in which the sheath acts as an abutment. Areas of greater flexibility can enable the natural motion of the heart. Increased flexibility is also advantageous for compressing the sheath into a delivery system. [0011] The sheath generally exhibits openings being created by the wires of the wire mesh, the links of the lattice structure, or by the holes formed in the sheath sleeve. The openings can be rectangular, diamond-shaped or round. The cells or holes can have a pin opening of 1 mm to 50 mm. A pin opening is defined as the largest diameter of a pin, which can be pushed through a cell or a hole. Using the holes, the stability and flexibility of the sheath can be adjusted individually. The holes also allow the exchange of substances from the inside of the sheath with the outer environment of the sheath. [0012] The sheath can be covered with a membrane; the membrane may, in particular, be made of polyurethane, silicon or polytetrafluorethylene (PTFE). The membrane can reduce the mechanical stress exerted by the sheath onto the pericardium or the myocardium. The membrane can also increase the biocompatibility of the sheath. A coating of the membrane with an active substance is also conceivable. [0013] Another aspect of the present invention features a method of manufacturing a cardiac assist device. The method includes using a virtual or real image of a heart and forming a sheath based on the shape of the heart image. [0014] The method can be used to manufacture a custom-made sheath. The shape of the sheath can match the form of the 3D-image of the surface of the heart, spatially stretched by a factor. In particular, the stretch factor can range from 1.01 to 1.2. A sheath applied to a true-to-scale real or virtual 3D image of the heart should exhibit a distance to the 3D image of 1 to 10 mm, in particular 2 to 8 mm, in particular 3 to 5 mm. [0015] Additional features and advantages of the invention will be apparent from the description and drawings, and from the claims. DESCRIPTION OF DRAWINGS [0016] FIG. 1 shows a human torso with an implanted device and an extracorporeal supply unit. [0017] FIG. 2 shows a human torso with an implanted device and a partially implanted supply unit. [0018] FIG. 3 shows a human heart with the device. [0019] FIGS. 4 a and 4 b show a cross-section through the heart with the device along line A-A in FIG. 3 . [0020] FIG. 5 shows a step of the implantation of the device. [0021] FIG. 6 shows a step of the implantation, in which a pericardium seal has not yet been screwed shut. [0022] FIG. 7 shows a step of the implantation, in which a pericardium seal is screwed shut. [0023] FIG. 8 shows a partially expanded sheath with a sleeve. [0024] FIGS. 9 a - c show different views of a closed pericardium seal. [0025] FIG. 10 shows a tool for the closing of a pericardium seal. [0026] FIG. 11 shows a plug connector system of the device. [0027] FIG. 12 a shows a heart with anatomical points of reference. [0028] FIG. 12 b shows a cross-section of the heart from FIG. 12 a. [0029] FIG. 13 a shows a 3D view of part of a heart with a system of coordinates. [0030] FIG. 13 b shows a 2D-rollout of the 3D view from FIG. 13 a with a system of coordinates. [0031] FIG. 14 a shows a 3D view of a sleeve with augmentation and positioning units. [0032] FIG. 14 b shows a 2D rollout of a sleeve with augmentation and positioning units from FIG. 14 a. [0033] FIGS. 15 a - b show one compressed and one expanded augmentation unit in the form of a chamber with a bellows-type section. [0034] FIG. 16 a shows a 3D view of a sleeve with sensors and/or electrodes. [0035] FIG. 16 b shows a 2D rollout of the sleeve with sensors and/or electrodes from FIG. 16 a. [0036] FIG. 17 shows a sample embodiment for a sleeve with augmentation and positioning units. [0037] FIG. 18 shows a sample embodiment for a sleeve with sensors and electrodes. DETAILED DESCRIPTION [0038] FIG. 1 shows an embodiment ( 10 ) of a device in the implanted state. In this example, the device is implanted into a human body. The device, however, can also be implanted into an animal body, in particular into the body of a mammal like a dog, a cat, a rodent, a primate, an even-toed ungulates or an odd-toed ungulate. Depending on the species, the form and the mode of operation of the device is adjusted, in order to accommodate anatomical and/or physiological needs of the individual species. [0039] FIG. 1 shows a human torso with the device. The device includes a sheath ( 2 ), which can at least partially enclose the heart ( 61 ). Multiple components inserted in the sheath ( 2 ) support the cardiac function ( 61 ). The device also includes a supply unit ( 30 ). [0040] The sheath ( 2 ), which can at least partially enclose the heart ( 61 ), is configured to transition from a non-expanded state into an expanded state. Preferably, the sheath ( 2 ) is self-expanding and can be inserted into a delivery system in the non-expanded state. The sheath ( 2 ) can be a mesh, in particular a wire mesh, whereby the wire mesh can be at least partially made of a shape memory alloy. [0041] The sheath ( 2 ) at least partially encloses the heart ( 61 ) in the implanted state and is located inside the pericardium ( 6 ). Embodiments in which the sheath ( 2 ) is placed outside of the pericardium ( 6 ) are possible as well. These embodiments are not described separately; rather, the description for embodiments for implantation inside and outside the pericardium ( 6 ) (with the exception of the not-required pericardial seal ( 5 ) in embodiments of the sheath ( 2 ) for implantation outside the pericardium ( 6 )) is applicable. The architecture of the sheath ( 2 ) is explained in greater detail in a later section of the description. [0042] Located inside the expandable sheath ( 2 ) is at least one expandable unit, which can be used to apply pressure to the heart ( 61 ). The expandable unit can be a mechanical unit, configured to transition between an expanded and a non-expanded state. Such a mechanical unit can include spring elements, which can be tensioned and released, or lever elements, which can be folded and unfolded. Preferably, the expandable units are chambers, which can be filled with a fluid. Suitable fluids for the filling of a chamber include liquids, gases, or solids (like nanoparticle mixtures, for example), or mixtures of fluids and/or gases and/or solids. The expandable unit can be secured inside the sheath ( 2 ). Preferably, the expandable unit is attached to a sleeve, which can be inserted into the sheath ( 2 ). The at least one expandable unit is described in greater detail with reference to FIG. 8 . [0043] The sheath ( 2 ) can furthermore include at least one sensor and/or one electrode, which can be used to detect at least one parameter of the heart ( 61 ). The sensor can be configured to determine the heart rate, the ventricular pressure, the contact force between the heart wall and the expandable unit, the systolic blood pressure, the diastolic blood pressure, the pressure applied to a surface of the heart, the fluid presence, the acidity, the electrical resistance, the osmolarity, the oxygen saturation or the flow through a vessel. The sensor can also be configured to measure the pressure applied by an expandable unit onto a surface, the pH-value, the electrical resistance, the osmolarity of a solution, the oxygen saturation of tissue or blood or the flow through a vessel. The sensor can be attached inside or on the sheath ( 2 ). Preferably, the sensor is secured on a sleeve configured to be inserted into the sheath ( 2 ). In addition to the at least one sensor or in place of the sensor, the sheath ( 2 ) can also include at least one electrode configured to measure a parameter, like e.g. the action potential at the myocardium during the excitation process, or to stimulate a tissue with currents. The sensor can also be an electrode. The sensor and the electrode are explained in greater detail in a later section of the description. [0044] FIG. 1 shows a supply unit ( 30 ), which can be worn outside the body. The supply unit can also be partially or completely implanted into the body, which will be explained in the following sections in greater detail. If the supply unit ( 30 ) is worn outside the body, it may be attached to a chest belt, to a hip belt, or to an abdominal belt. The supply unit ( 30 ) is equipped with an energy storage device allowing the expandable unit to be powered. The energy storage device can be available in the form of a rechargeable battery providing electrical energy to expand the expandable unit. The rechargeable battery is exchangeable. The supply unit ( 30 ) can also include a pressure storage device supplying a compressed gas, to inflate an inflatable chamber. Suitable gases are, among others, compressed air, CO 2 , or inert gases. The housing of the supply unit ( 30 ) itself can serve as a pressure storage housing. The supply unit ( 30 ) can furthermore contain pumps, valves, sensors and displays. The supply unit ( 30 ) can furthermore include a microprocessor configured to receive and process data from the at least one sensor. If the supply unit ( 30 ) is worn outside the body, the required energy can be transferred by direct connection via a cable ( 4 ) or connectionless via electromagnetic induction, for example. The data from the at least one sensor can also be transmitted directly via a cable ( 4 ) or connectionless via wireless technology like bluetooth, for example. [0045] The device according to the invention can furthermore include a cable ( 4 ) connecting the expandable unit and/or the sensor or the electrode to the supply unit ( 30 ). If the supply unit ( 30 ) is connected directly to the expandable unit and/or to the sensor, or the electrode, a cable ( 4 ) is not required. If the expandable unit is a mechanical unit which, using electrical energy, is configured to transition from a non-expanded state into an expanded state, or from an expanded state into a non-expanded state, the cable ( 4 ) includes lines configured to transfer the required energy from the supply unit ( 30 ) to the expandable unit. The sleeve can include internal chambers, configured to enable hydraulic alteration of the volume of at least one of the internal chambers of the sleeve. If the expandable unit is a chamber that can be filled by means of a fluid, the cable ( 4 ) includes at least one line allowing the flow of fluid from the supply unit ( 30 ) into the chamber. In some implementations, the cable ( 4 ) includes at least one pneumatic or hydraulic line. If the device includes one sensor or one electrode at, in or on the sheath, then the line leading to the sensor or the electrode can also be in the cable ( 4 ). Embodiments can also exhibit separate cables for providing energy for the expandable unit and for the sensor, or the electrode. [0046] The cable ( 4 ) connecting the supply unit ( 30 ) to the expandable unit and/or the sensor, or the electrode, can be a single continuous cable or a multi-part cable. In the case of a continuous cable connection, the cable ( 4 ) can be attached to the expandable unit and/or the sensor or one electrode. A connector ( 90 ) can be attached to the end of the cable ( 4 ). The connector ( 90 ) can be connected to the supply unit ( 30 ) via the matching connector ( 91 ). Alternatively, a cable with a connector is only attached to the supply unit ( 30 ). In this case, the matching connector is installed on the sheath ( 2 ), on the expandable unit and/or on the sensor or electrode. In case of a multi-part cable, a cable ( 4 ) with a connector ( 91 ) can be attached to the expandable unit and/or at the sensor or the electrode, and a cable can also be attached to the supply unit ( 30 ), at the end of which can be a connector. The cable ( 4 ) and the connector ( 90 ) are described in greater detail in a later section of the description. [0047] FIG. 2 shows an embodiment ( 11 ) of the device in the implanted state, where the supply unit ( 31 ) is implanted into the body. Preferred locations for the implantation of the supply unit ( 31 ) are the chest (thoracic) cavity and the abdominal (peritoneal) cavity, which are separated from each other by the diaphragm ( 63 ). [0048] The sheath ( 2 ) shown in FIG. 2 , the pericardium seal ( 5 ), and the cable ( 4 ) of the device are essentially identical to the components shown in FIG. 1 . The supply unit ( 31 ) can include an energy storage device, which can be used to power the expandable unit located inside the sheath ( 2 ). The energy storage device can be provided in the form of a rechargeable battery, which supplies electrical energy in order to expand the expandable unit. The supply unit ( 31 ) can furthermore contain sensors and one or more microprocessors. If the expandable unit includes at least one chamber, which can be filled with a fluid, then the supply unit ( 31 ) can include pumps, valves, and a pressure reservoir. The pressure reservoir can provide a compressed gas in order to inflate an inflatable chamber. Suitable gases are, among others, compressed air, CO2, or inert gases. The housing of the supply unit ( 31 ) itself can represent the housing of the pressure reservoir. A preferred place for the implantation of the supply unit ( 31 ) is inside the right lateral chest cavity above the liver ( 62 ) and above the diaphragm ( 63 ). Alternatively, or in addition to the pressure reservoir ( 32 ) in the supply unit ( 31 ), the pressure reservoir ( 32 ) can be preferably implanted inside the right lateral abdominal cavity below the diaphragm ( 63 ) and above the liver ( 62 ). [0049] The pressure reservoir ( 32 ) can be connected to the supply unit ( 31 ) with a tube ( 33 ), which penetrates the diaphragm ( 63 ). The opening in the diaphragm required for the tube ( 33 ) to pass through can be sealed with a seal. The seal can be designed similar to the pericardium seal, as previously described. The supply unit can be connected via a cable ( 4 ) directly with the expandable unit and/or the sensor, or the electrode. Alternatively, at the end of the cable ( 4 ) can also be a connector configured to connect via a matching connector to the supply unit ( 31 ) or to the expandable unit and/or to the sensor or the electrode. [0050] The cable ( 4 ) runs preferably in the chest cavity above the diaphragm ( 63 ). In the case of a multi-part cable, a cable with a connector can be attached to the expandable unit and/or the sensor or one electrode, and a cable with a matching connector can be attached to the supply unit ( 31 ). [0051] Alternatively or in addition to a rechargeable battery in the supply unit ( 31 ), a rechargeable battery ( 34 ) can be implanted subcutaneously, into the abdominal wall. The energy required in the supply unit ( 31 ) can be transferred, for example, by electromagnetic induction from an extracorporeal controller ( 35 ) transcutaneously to the rechargeable battery ( 34 ) and be transmitted by an electric cable ( 36 ) from the rechargeable battery ( 34 ) to the supply unit ( 31 ). The extra-corporeal controller ( 35 ) can include an exchangeable rechargeable battery and/or a charging device. The extracorporeal controller ( 34 ) can contain, among others, microprocessors and displays, which can be used for system monitoring of the device and for a display of the operating status. The data from the sensor can be transmitted connectionless via a wireless technology like bluetooth, for example, to and between the supply unit ( 31 ) and the controller ( 34 ). [0052] FIG. 3 shows an example of a human heart ( 61 ), as well as a sheath ( 2 ), a sleeve ( 7 ) with expandable units ( 71 , 72 ), a sleeve ( 80 ) with sensors ( 81 ) and/or electrodes a cable ( 4 ) with a connector ( 90 ), a catheter ( 103 ) of a delivery system, and a pericardium seal ( 5 ) of the device according to the invention. [0053] In this embodiment, the sheath ( 2 ) is shown in the form of a wire mesh. Instead of a wire mesh, the sheath ( 2 ) can alternatively be formed as a lattice consisting of links. In this case, the links create a lattice structure with openings. The sheath ( 2 ) can also consist of a continuous material, from which parts have been removed; for example, the sheath ( 2 ) can consist of a tube and an individually shaped sheath sleeve, into which holes have been formed or cut. [0054] The sheath ( 2 ) represented in FIG. 3 consists of a mesh made of wires. The wires form crossing points (intersections), which can be permanently interconnected. The wires could, for example, be welded together at their crossing points. Connecting the wires at crossing points increases the stability of the sheath ( 2 ). The crossing points can be free from each other, increasing the flexibility of the sheath ( 2 ) and therefore leading to an easier compressibility of the sheath ( 2 ). In some embodiments, the sheath includes wires that do not cross each other, forming longitudinally oriented struts. Increased sheath flexibility is especially helpful if the sheath ( 2 ) is to be inserted into a delivery system with a smaller diameter catheter ( 103 ). Some of the crossing points of the sheath ( 2 ) can also be permanently interconnected and others not. Through appropriate selection of crossing points, which are permanently interconnected and crossing points, which are separable, the stability and flexibility of the sheath ( 2 ) can be customized. Areas requiring increased stability in the implanted state can be stabilized by connecting the wires at the crossing points. These can be areas serving as bearing surfaces or abutments for expandable units ( 71 , 72 ). Such abutments can be located directly under an expandable unit ( 71 , 72 ) or next to areas with expandable units ( 71 , 72 ). Areas requiring increased flexibility can be areas, which during insertion into a delivery system must be compressed more than other areas. Areas requiring increased flexibility can also be areas, in which an increased flexibility supports the natural movement of the heart. If the sheath ( 2 ) is not made of a wire mesh but of a latticework or a sheath sleeve with holes, the stability and/or the flexibility of the sheath ( 2 ) can be adjusted at areas as well. In these cases, adjustments can be brought about by choosing the width of the links and/or the thickness of the links, through the choice of the material to be used, through modifications of the material in certain areas through application of energetic radiation, like heat, for example. Preferably, the sheath ( 2 ) exhibits openings being formed by the wires of a wire mesh, the links of a latticework, or the holes in a sheath sleeve. These openings enable compression of the sheath ( 2 ); they allow the exchange of substances from inside the sheath ( 2 ) with areas outside the sheath ( 2 ) and vice versa; they reduce the amount of material being used for the sheath ( 2 ), and they allow an increased flexibility of the sheath ( 2 ). Shapes, which are difficult to realize with solid materials are easier to achieve with mesh-type or lattice-type structures. The openings can be rectangular, round or oval. The openings defined by the wires, the links or the holes in a sheath sleeve have a diameter of approximately 1 to 50 mm, preferably 4 mm to 10 mm. The diameter of an opening is defined as pin opening, meaning that the diameter of the opening represents the largest diameter of a cylindrical pin that can pass through an opening (e.g., a cell or a hole). [0055] The sheath ( 2 ) is preferably made of a material allowing expansion. Preferably, the sheath ( 2 ) is formed from a material selected from the group consisting of nitinol, titanium and titanium alloys, tantalum and tantalum alloys, stainless steel, polyamide (PA), polyurethane (PUR), polyether ether ketone (PEEK), polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyethylene terephthalate (PET), polymer fiber materials, carbon fiber materials, aramide fiber materials, glass fiber materials and combinations thereof. A material suitable for forming a self-expanding sheath ( 2 ) is at least partially made of a shape memory alloy. Examples of shape memory alloys include NiTi (nickel-titanium; nitinol), NiTiCu (nickel-titanium-copper), CuZn (copper-zinc), CuZnAl (copper-zinc-aluminum), CuAlNi (copper-aluminum-nickel), FeNiAl (iron-nickel-aluminum) and FeMnSi (iron-manganese-silicon). [0056] The sheath ( 2 ) preferably exhibits a form adapted to the individual shape of the patient's heart, or a cup-shaped form. The individual shape of the patient's heart can be reconstructed from CT or MRI image data. The sheath ( 2 ) is open at the top. The upper rim of the sheath ( 2 ) preferably exhibits loops of a wire or straps, which are formed by links. The loops or straps can serve as anchoring points for a sleeve ( 80 ) with at least one sensor ( 81 ) or one electrode, and/or for a sleeve ( 7 ) with at least one expandable unit ( 71 , 72 ). Positioned at the lower end of the cup-shaped sheath is preferably an opening, through which one or multiple leads of the sensor ( 81 ) or of the electrode, and/or of the expandable unit ( 71 , 72 ) can be passed. The shape of the sheath ( 2 ) at least partially represents the anatomical shape of a heart ( 61 ), in particular the lower part of a heart ( 61 ). Details regarding the shape of the sheath ( 2 ) are explained in greater detail in a later section of the description. [0057] The sheath ( 2 ) can be covered by a membrane ( 21 ), in particular by a membrane ( 21 ) made of polyurethane or silicon. The membrane ( 21 ) is configured to reduce the mechanical stress applied by the sheath ( 2 ) onto the pericardium ( 6 ) or the myocardium ( 61 ). The membrane ( 21 ) can also increase the biocompatibility of the sheath ( 2 ). The membrane ( 21 ) can be attached to the inner surface or to the outer surface of the sheath ( 2 ). The membrane ( 21 ) can also be manufactured by dipping the mesh- or lattice-type sheath ( 2 ) into an elastomer-containing liquid, and subsequently envelops the latticework or the mesh. The membrane ( 21 ) can then stretch across the openings of the mesh or the lattice. A membrane ( 21 ) on the mesh or the lattice can also improve the abutment properties of an expandable unit ( 71 , 72 ). If an expandable unit ( 71 , 72 ) is, for example, an inflatable chamber, a membrane ( 21 ) across, at or on the mesh or the lattice can prevent parts of the chambers being pressed through the mesh or the lattice while the chamber is expanding. The membrane ( 21 ) can furthermore prevent excessive widening of the sheath ( 2 ), in particular during inflation of an inflatable chamber. A membrane ( 21 ) on a mesh or a lattice can ensure that an expandable unit positioned on the lattice or the mesh expands into a direction from the mesh or lattice towards the inside only. The membrane ( 21 ) does not interfere with the compressibility of the sheath ( 2 ) while being inserted into a delivery system. [0058] The sheath ( 2 ) and/or the membrane ( 21 ) can also include an active pharmaceutical ingredient, for example, an anti-thrombotic ingredient, an anti-proliferative ingredient, an anti-inflammatory ingredient, an anti-neoplastic ingredient, an anti-mitotic ingredient, an anti-microbial ingredient, a biofilm synthesis inhibitor, an antibiotics ingredient, an antibody, an anti-coagulating ingredient, a cholesterol-lowering ingredient, a beta blocker, or a combination thereof. Preferably, the ingredient is in the form of a coating on the sheath ( 2 ) and/or the membrane ( 21 ). The sheath ( 2 ) and/or the membrane ( 21 ) can also be coated with extra-cellular matrix proteins, in particular fibronectin or collagen. Bio-compatible coating can be advantageous if ingrowth of the sheath ( 2 ) is desired. [0059] The expandable unit ( 71 , 72 ) is located inside the sheath ( 2 ). FIG. 3 shows a sheath ( 2 ), into which a sleeve ( 7 ) with expandable units ( 71 , 72 ) in the form of inflatable chambers is inserted. The expandable unit ( 71 , 72 ) is being supplied by a line ( 41 ) inside the cable ( 4 ). The expandable unit ( 71 , 72 ) can be a hydraulic or a pneumatic chamber. The expandable unit ( 71 , 72 ) can be attached directly to the sheath ( 2 ) without a sleeve ( 7 ). The expandable unit ( 71 , 72 ) can also be attached to a sleeve ( 7 ), and the sleeve ( 7 ) can be attached inside the sheath ( 2 ). The expandable unit ( 71 , 72 ) can be designed to apply pressure to the heart ( 61 ). The applied pressure can be a permanent pressure, or it can be a periodically recurring pressure. The device according to the invention can include different types of expandable units ( 71 , 72 ). The device can include at least one augmentation unit ( 71 ). The device can include at least one positioning unit ( 72 ). The augmentation unit ( 71 ) and/or the positioning unit ( 72 ) can be attached directly to the sheath ( 2 ) or onto a sleeve ( 7 ), which is inserted into the sheath ( 2 ). [0060] An augmentation unit ( 71 ) is a unit, which can be periodically expanded and relaxed, and thereby applies a rhythmical pressure to the heart ( 61 ). The pressure is preferably applied in the areas of the heart muscle, under which a ventricle is located. By applying pressure on a ventricle by means of the augmentation unit ( 71 ) the natural pumping motion of the heart ( 61 ) is being amplified or substituted, and the blood inside the heart ( 61 ) is pumped from the ventricle into the discharging artery. A pressure applied by an augmentation unit ( 71 ) to a right ventricle assists the ejection of the blood from the right ventricular chamber into the pulmonary artery. A pressure applied by an augmentation unit ( 71 ) to a left ventricle assists the ejection of the blood from the left ventricular chamber into the aorta. The positioning of the augmentation unit ( 71 ) inside the sheath ( 2 ) is explained in greater detail in a later section of the description. [0061] A positioning unit is preferably expanded during the operation of the device in support of the heart function more statically than periodically. The positioning unit ( 72 ) can be expanded in order to fixate the device to the heart and to ensure proper fitting of the device. A positioning device ( 72 ) can also be used to respond to changes in the myocardium (e.g., shrinking of the myocardium due to lack of fluids or enlargement of the myocardium due to the absorption of fluids). If the size of the myocardium decreases or increases within a particular period of time, a positioning unit can be expanded or relaxed further in order to ensure a perfect fit. The positioning unit ( 72 ) may, for example, also be used to ensure that the device does not lose contact to the heart wall over the span of a heartbeat. Loss of contact can lead to impact stress between the myocardium and the device, and/or cause malfunction of the sensors ( 81 ) and/or electrodes. In some implementations, the positioning unit ( 72 ) can counteract the pathological, progressive expansion of the damaged myocardium in heart failure patients. The positioning of the positioning unit ( 72 ) inside the sheath ( 2 ) is explained in greater detail in a later section of the description. [0062] Located at the lower end of the sheath ( 2 ) can be an opening, through which the lead ( 83 ) from the sensor ( 81 ) or the electrode and/or the line ( 41 ) of the expandable unit ( 71 , 72 ) can be passed. The opening can be installed at the lower distal end of the sheath ( 2 ). Alternatively, the opening can also be installed on one side of the sheath ( 2 ). Shown in FIG. 3 is an opening at the lower distal end of the sheath ( 2 ), through which one cable ( 4 ), which includes all leads ( 41 , 83 ), has been routed. Instead of one cable ( 4 ), there can be multiple separate cables. The cables can be routed through one opening of the sheath ( 2 ) or through multiple openings of the sheath ( 2 ). Attached to the end of the cable ( 4 ) is a connector ( 90 ), which is used to connect the sensor ( 81 ) or the electrode, and/or the expandable unit ( 71 , 72 ) to a supply unit. The sheath ( 2 ) is preferably brought inside the pericardium ( 6 ). The cable ( 4 ) is then passed through the pericardium ( 6 ). The device according to the invention can include a pericardium seal ( 5 ). The seal can seal the opening of the pericardium, which is required for the cables to pass through. The pericardium ( 6 ) is a connective-tissue-type sac surrounding the heart ( 61 ), and which, due to a narrow lubricant layer, gives the heart ( 61 ) the ability to move freely. As a lubricant, it contains a serous fluid, also called liquor pericardii. In order to prevent this lubricant from escaping from the pericardium ( 6 ) through the cable opening, and to prevent any other fluids or solids (like, for example, cells, proteins, foreign matter, etc.) from entering the pericardium ( 6 ), a pericardium seal ( 5 ) can be installed around the cable ( 4 ). The pericardium seal ( 5 ) seals the opening of the pericardium ( 6 ) to the cable ( 4 ). The pericardium seal ( 5 ) can include a first sealing component with a first sealing lip, and a second sealing component with a second sealing lip. A cable ( 4 ) can be routed through a central lumen of the seal. The first sealing lip and/or the second sealing lip can seal the pericardium opening. Located inside the central lumen can be an additional sealing component, which seals the cable ( 4 ) against the pericardium seal ( 5 ) and, if necessary, fixates it as well. The first and the second sealing component can be combined. Preferably, the first and the second sealing component can be secured with a mechanism. Possible mechanisms to secure the sealing components are screw mechanisms, clamping mechanisms, or a bayonet mechanism. The first sealing component and/or the second sealing component can be expandable, or even self-expanding. The pericardium seal ( 5 ) is explained in greater detail in a later section of the description. [0063] FIGS. 4 a and 4 b show a cross-section of the heart ( 61 ) and part of the device for the support of the cardiac function ( 61 ) along line A-A in FIG. 3 . Starting from the outside to the inside, the following layers are represented: The sheath ( 2 ) with a membrane ( 21 ), a sleeve ( 7 ) with at least one expandable unit ( 71 , 72 ), a sleeve ( 80 ) with at least one sensor ( 81 ) or one electrode ( 82 ), and a transverse cross-section of the heart ( 60 ). Three augmentation units ( 71 ) and three positioning units ( 72 ) are illustrated as examples. In FIG. 4 a , the expandable units ( 71 , 72 ) have been drawn in the non-expanded state. In FIG. 4 b , the augmentation units ( 71 ) have been drawn in the expanded state. The expandable unit ( 71 , 72 ) is located in an area adjacent to a ventricle. An expansion of the expandable unit ( 71 , 72 ) can reduce the volume of the ventricle and cause blood to be ejected from the ventricular chamber. The sensor ( 81 ) or the electrode ( 82 ) is installed in a particular location, where at least one parameter of the heart ( 61 ) can be measured. An electrode ( 82 ) can be installed in a particular location, where the myocardium can be stimulated. In FIGS. 4 a and 4 b , four sensors ( 81 ) in the sleeve ( 80 ) and three electrodes ( 82 ) at the inside of the sleeve ( 80 ) are illustrated as examples. [0064] FIG. 5 shows a delivery system ( 100 ), which can be used to implant the device to support the cardiac function. The delivery system ( 100 ) includes a catheter ( 103 ), which has a lumen. Preferably, the catheter ( 103 ) is an elongated, tubular component, into which the device for the support of the cardiac function can be inserted in its compressed state. The cross-section of the catheter ( 103 ) and/or of the lumen can be round, oval or polygonal. The delivery system ( 100 ) can further include a guide wire ( 101 ) and/or a dilatation component. The dilatation component can be soft cone-shaped tip ( 102 ) with a shaft. The guide wire ( 101 ) can be passed through a puncture of the chest wall ( 65 ) between the ribs ( 64 ) and of the pericardium ( 6 ). The soft, cone-shaped tip ( 102 ) can have at the center a round, oval or polygonal lumen. The soft, cone-shaped tip ( 102 ) can be pushed over the guide wire ( 101 ) and the puncture can be dilated without injury to the epicardium. The distal section of the catheter ( 103 ) of the delivery system ( 100 ) can be passed through the dilated opening. At the distal end of the catheter ( 103 ), a first sealing component ( 51 , 52 ) of the pericardium seal can be snapped on or otherwise attached. The catheter ( 103 ) may, for example, be pushed onto a cone ( 55 ) located at the end of the first sealing component ( 51 , 52 ). Not shown is another embodiment, where a cone is located at the side of the catheter, onto which the first sealing component can be pushed. The catheter ( 103 ) with the attached first sealing component ( 51 , 52 ) of the pericardium seal can be guided via the shaft of the soft tip ( 102 ) and inserted into the pericardium ( 6 ). [0065] Alternatively, the catheter ( 103 ) and the first sealing component ( 51 , 52 ) of the pericardium seal can be parts that are not interconnected to each other. In this case, the catheter ( 103 ) is initially inserted into the pericardium ( 6 ), and the first sealing component ( 51 , 52 ) can then be pushed into the pericardium via the catheter or withdrawn from the pericardium ( 6 ) through the lumen of the catheter ( 103 ). The first sealing component ( 51 , 52 ) can be a self-expanding sealing component, and is configured to unfold inside the pericardium ( 6 ). Alternatively, a non-expandable part ( 51 ) of the first sealing component contains a self-expanding sealing lip ( 52 ) or a sealing lip ( 52 ), which is configured to fold down while the first seal component ( 51 , 52 ) is being inserted, and which opens up inside the pericardium ( 6 ). The first sealing component ( 51 , 52 ) can expand into a mushroom or umbrella-like shape. [0066] A second sealing component ( 53 , 54 ) can be inserted along the catheter ( 103 ) or through the catheter ( 103 ). For example, the second sealing component ( 53 , 54 ) can be moved via the catheter ( 103 ) of the delivery system ( 100 ) to the distal end of the delivery system ( 100 ), and then coupled with the first sealing component ( 51 , 52 ). The second sealing component ( 53 , 54 ) can be expandable or non-expandable. The second sealing component ( 53 , 54 ) can be coupled to the first sealing component ( 51 , 52 ). The second sealing component ( 51 , 52 ) is preferably self-expanding, and can in its expanded form assume the shape of a mushroom or an umbrella. The second sealing component ( 53 , 54 ) can be secured with the first sealing component ( 51 , 52 ). Shown in FIG. 5 is a screw mechanism. Other mechanisms to secure the sealing components ( 51 , 52 , 53 , 54 ) include a clamping mechanism or a bayonet seal. After securing of the sealing components ( 51 , 52 , 53 , 54 ), the catheter ( 103 ) of the delivery system ( 100 ) can remain on the cone ( 55 ) of the first sealing component ( 51 ) or remain in the lumen of the sealing component ( 51 , 52 ). After the guide wire ( 101 ) and the shaft of the soft tip ( 102 ) have been pulled out of the catheter, of the catheter ( 103 ). The sheath is preferably self-expanding, and encloses the heart ( 61 ) after expansion at least partially. Located at the lower end of the sheath can be a connector or a cable with a connector. The supply unit can be directly attached to the sheath, or be connected to the sheath via a cable. After the sheath has been delivered, the delivery system ( 100 ) can be removed. The delivery system ( 100 ) is detached from the sheath by using a pre-weakened breaking point ( 104 ) of the delivery system ( 100 ) and/or on the catheter ( 103 ). Preferably, there are one or multiple pre-weakened breaking points ( 104 ) along a longitudinal axis of the delivery system ( 100 ). The pre-weakened breaking point ( 104 ) can be represented by a breaking line. When the delivery system ( 100 ) is broken open along a pre-weakened breaking point ( 104 ), the delivery system ( 100 ) can be split, unrolled and removed. The delivery system ( 100 ) can also include grasping components ( 105 ), which can be used to apply a force to the delivery system ( 100 ). Preferably, the grasping components ( 105 ) can be used to apply a force directed sideways from the catheter ( 103 ) onto the delivery system ( 100 ) suitable to break open the pre-weakened breaking point ( 104 ). [0067] The delivery system ( 100 ) can further include a sensor ( 107 ). The sensor can be a temperature sensor ( 106 ) to measure the temperature within the catheter before and during the implantation of the (heart assist device/system)/(sheath?). The temperature sensor ( 107 ) can include a thermocouple, a crystal oscillator or an infrared camera. Alternatively, the sensor can be a sensor to measure at least one of the temperature, pH-value, osmolarity and oxygen saturation of a fluid within the catheter. The wall of the catheter ( 103 ) can further contain heating elements ( 108 ). [0068] The heating elements ( 108 ) can be used to heat the catheter ( 103 ) and its content before or during implantation. The delivery system ( 100 ) can contain one, two, three, four or more heating elements ( 108 ). The heating elements ( 108 ) can be arranged along the circumference of the catheter wall ( 103 ) equidistantly or unregularly. The heating elements ( 108 ) can span the whole length of the catheter ( 103 ) or cover the length of the catheter only partially. The heating elements ( 108 ) can be adjacent to the catheter wall ( 103 ) at the inside or the outside or they can be within the catheter wall. [0069] The heating elements ( 108 ) can include heating filaments, heating coils or heating wires, which produce heat via an electrical current. The heating elements ( 108 ) can further consist of ducts within the catheter wall that are perfused by a tempered fluid. The catheter can be heated by using a perfusion fluid whose temperature is higher than the ambient temperature. The ducts can also be perfused by a fluid whose temperature is lower than the ambient temperature, in this way the ducts are utilized to cool down the catheter and its content to lower temperature. With a temperature sensor and the heating elements, the temperature within the catheter can be maintained at a specific level between −5° C. and +40° C. [0070] FIG. 6 shows a step of the implantation of the device according to the invention. After the first sealing component ( 51 , 52 ) in the pericardium ( 6 ) has assumed the expanded form, the sheath ( 2 ), which is preferably self-expanding, can be passed through the lumen of the catheter ( 103 ) of the delivery system and lumen of the first sealing component ( 51 ). After entering through the pericardium seal, the sheath ( 2 ) with the sensor or the electrode and/or the expandable unit expands inside the pericardium ( 6 ). [0071] Shown in FIG. 6 is also the second sealing component ( 58 , 59 ) before being coupled with the first sealing component ( 51 , 52 ). In this embodiment, the second sealing component ( 58 , 59 ) is a ring-shaped component ( 58 ), e.g., a nut, on which a sealing disk ( 59 ) can be attached to its distal side. The second sealing component ( 58 , 59 ) can be expandable or non-expandable. The second sealing component ( 58 , 59 ) can be moved on the catheter ( 103 ). In this embodiment, the first ( 51 , 52 ) the sheath with the sensor or the electrode and/or with the expandable unit can be inserted through the lumen and the second sealing component ( 58 , 59 ) exhibit thread sections, which can be screwed together. [0072] FIG. 7 shows a step of the implantation of the device according to the invention. In this embodiment, the first sealing component ( 51 , 52 ) is coupled with the second sealing component ( 53 ). The pericardium ( 6 ) can thereby be sealed. The expandable sheath ( 2 ) is partially located inside the pericardium ( 6 ) and can be expanded. FIG. 7 shows markings ( 22 , 23 , 24 ) applied to the sheath ( 2 ). The device according to the invention generally contains at least one marking ( 22 , 23 , 24 ), which can facilitate the correct placing of the sheath ( 2 ). The marking ( 22 , 23 , 24 ) can be a visual mark, in particular a color marking. The marking ( 22 , 23 , 24 ) can be a phosphorescent or fluorescent marking, making it easier to see in dark environment. Such environments can be present in the operating room itself, and can also be caused by the casting of shadows. Such environments can also be inside the body of a patient. The marking ( 22 , 23 , 24 ) can be made of a material able to be represented by imaging techniques. Suitable imaging techniques include X-rays, CT-methods, and MRI-methods. For example, the marking ( 22 , 23 , 24 ) can be formed of a more radiopaque material than the material of adjacent regions. The marking ( 22 , 23 , 24 ) can have the form of a point, a circle, an oval, a polygon, or the form of a letter. Other forms can be areas created by the connecting of dots. The form can be, for example, a half-moon or a star. The marking ( 22 , 23 , 24 ) can be applied to the sheath ( 2 ) or applied to a sleeve. The marking can be applied in the form of a line. The line can start at the upper edge of the sheath ( 2 ). The line can run from an upper edge of the sheath ( 2 ) to a point at the lower tip of the sheath ( 2 ). The line can run from the upper edge of the sheath perpendicular to the lower tip of the sheath ( 2 ). The starting point of the line at the upper edge of the sheath ( 2 ) can be located at a place, which in the implanted state is close to an area or at an area, which is level with the cardiac septum. The marking ( 22 , 23 , 24 ) can be located at crossing points of the mesh or the lattice. If the sheath ( 2 ) includes a sheath sleeve, into which holes were formed, the marking ( 22 , 23 , 24 ) can be worked into the sheath sleeve. For example, a hole can be manufactured with a predefined form, which then serves as marking ( 22 , 23 , 24 ). [0073] The delivery system and/or the catheter ( 103 ) of the delivery system can include one or multiple markings ( 106 ). A marking ( 106 ) on a delivery system can be formed like a marking on a sheath. The marking ( 106 ) can have the form of a dot or the form of a line. A marking ( 106 ) in the form of a line can be a line, which at least partially describes a circumference of the delivery system. A marking ( 106 ) in the form of a line can be a longitudinal line along an axis of the delivery system. A marking ( 106 ) in the form of line can be a straight line or a meandering line. A marking ( 106 ) in the form of a line can be a line running diagonally on a catheter ( 103 ) of a delivery system. A marking ( 106 ) can facilitate the orientation of the delivery system during implantation. A marking ( 106 ) at or on the delivery system can be in alignment with a line at or on a medical implant. For example, the medical implant can be a device for the support of the cardiac function, which can be compressed. In a compressed state, the device can be inserted into a delivery system. One or multiple markings ( 22 , 23 , 24 ) on or at the device can be aligned with one or multiple markings ( 106 ) on or at the delivery system. Such markings ( 22 , 23 , 24 , 106 ) facilitate the orientation of a medical implant. Markings ( 22 , 23 , 24 ) can also be located along an axis of a medical implant. Such markings ( 22 , 23 , 24 ) can be helpful in tracking the progress of the discharge of a medical implant out of the delivery system. The delivery system and/or a catheter ( 103 ) can be made of a transparent material, which allows the medical implant to be visually traceable during insertion. [0074] FIG. 8 shows a step of the implementation of the device. In this example, the first sealing component ( 51 , 52 ) and the second sealing component ( 53 ) of the pericardium seal are interconnected. The device for the support of the cardiac function has already been partially discharged from the delivery system. Shown is a self-expanding sheath ( 2 ). In this embodiment, the sheath ( 2 ) is formed from a wire mesh exhibiting loops ( 26 , 28 ) at the upper edge and/or at the lower edge of the sheath ( 2 ). The sheath ( 2 ) can also be formed of a lattice structure and can exhibit links in the form of straps at the upper edge and/or at the lower edge of the sheath ( 2 ). If the sheath ( 2 ) is formed from a sheath sleeve, into which holes have been formed, the upper edge and/or the lower edge of the sheath ( 2 ) can be designed such that at least one strap is located at the upper and/or lower edge of the sheath ( 2 ). The sheath ( 2 ) represented in FIG. 8 includes a sleeve ( 80 ), which is inserted into the sheath ( 2 ). Another sleeve including at least one expandable unit can be located between the sleeve ( 80 ) and the sheath ( 2 ). [0075] One or both sleeves can be fastened to the loops ( 26 , 28 ) or straps of the sheath ( 2 ). A sleeve can, in particular, be hooked onto the loops ( 26 , 28 ) or the straps of the sheath ( 2 ). In such case, the sleeve ( 80 ) can exhibit at least one pocket ( 27 ), which can be pulled over at least one loop ( 26 , 28 ) or at least one strap. Another embodiment can include a sleeve ( 80 ), which is turned inside out at its upper edge and/or at its lower edge. This inversion can form a pocket ( 27 ) around the entire sleeve ( 80 ) or around a part thereof, which can be hooked into the upper edge and/or the lower edge of the sheath ( 2 ). In FIG. 8 , the sheath ( 2 ) exhibits multiple markings ( 22 , 23 , 24 , 25 ). As previously described, these markings ( 22 , 23 , 24 , 25 ) can assume different forms or positions. In this case, the markings ( 22 , 23 , 24 , 25 ) are attached to the upper edge and the lower tip of the sheath ( 2 ). [0076] FIGS. 9 a - c show different views of a pericardium seal ( 5 ). The pericardium seal ( 5 ) serves to prevent the loss of pericardium fluid or also as an option to apply artificial pericardium fluid, medications or other therapeutics. The prevention of loss of pericardium fluid also serves to prevent adhesions of the system with the epicardium. The pericardium seal ( 5 ) generally includes a first sealing component ( 51 ) and a second sealing component ( 52 ). The first sealing component ( 51 ) has a central lumen, and the second sealing component ( 53 ) has a central lumen. The first sealing component ( 51 ) can be coupled with the second sealing component ( 53 ). After coupling the first sealing component ( 51 ) to the second sealing component ( 52 ), the pericardium seal ( 5 ) exhibits a lumen running through the pericardium seal ( 5 ). The lumen can be formed exclusively by the central lumen of the first sealing component ( 51 ), or the lumen can be formed exclusively by the central lumen of the second sealing component ( 53 ). In another embodiment, the lumen can also be formed from both lumens of the two coupled sealing components ( 51 , 53 ). Located in the lumen can be a sealing gasket, an O-ring, a labyrinth seal or another sealing component ( 56 ). A sealing component ( 56 ) in the lumen of the pericardium seal can seal the pericardium seal ( 5 ) against an object protruding through the pericardium seal ( 5 ). For example, a cable can be passed through the pericardium seal ( 5 ), which is then sealed against the pericardium seal ( 5 ). A sealing component ( 56 ) in the lumen can serve not only to seal but also to fixate an object protruding through the lumen of the pericardium seal. The sealing component ( 56 ) can be attached to both sealing components ( 51 , 53 ) or to one of both sealing components ( 51 , 53 ) only. [0077] Using a mechanism, the first sealing component ( 51 ) can be secured with the second sealing component ( 53 ). A mechanism to secure a first sealing component ( 51 ) with a second sealing component ( 53 ) can include a screw mechanism or clamping mechanism. A mechanism to secure a first sealing component ( 51 ) with a second sealing component ( 53 ) can also include a bayonet catch. The first sealing component ( 51 ) and the second sealing component ( 53 ) can be made of the same material or made of different materials. Suitable materials for the first sealing component ( 51 ) and/or the second sealing component ( 53 ) include synthetic materials, metals, ceramics or combinations thereof. [0078] Attached to the first sealing component ( 51 ) can be a first sealing lip ( 52 ). The first sealing lip ( 52 ) can be part of the first sealing component ( 51 ) or can be attached to the first sealing component ( 51 ). Attached to the second sealing component ( 53 ) can be a second sealing lip ( 54 ). The second sealing lip ( 54 ) can be part of the second sealing component ( 53 ) or can be attached to the second sealing component ( 53 ). The first sealing lip ( 52 ) and the second sealing lip ( 54 ) can be formed of the same material or of different materials. One or both sealing lips ( 52 , 54 ) can be part of the respective sealing component ( 51 , 53 ) and can be formed from the same material as the associated sealing component ( 51 , 53 ). The first sealing lip ( 52 ) and/or the second sealing lip ( 54 ) can be formed of a synthetic material (preferably of an elastomer), natural rubber, rubber, silicon, latex or a combination thereof. The first sealing lip ( 52 ) and/or the second sealing lip ( 54 ) can be disk-shaped. The first sealing lip ( 52 ) and/or the second sealing lip ( 54 ) can exhibit a concave or a convex curvature. Curved sealing lips ( 52 , 54 ) can better adapt to anatomic conditions. The pericardium exhibits a convex form in the area of the cardiac apex. With the sealing lips ( 52 , 54 ) exhibiting a curvature in the shape of the anatomically available form, an improved anatomic fit of the pericardium seal ( 5 ) can be achieved. [0079] Curved sealing lips ( 52 , 54 ) can also be used to achieve better sealing properties. The first sealing lip ( 52 ) and/or the second sealing lip ( 54 ) can have reinforcements. With increasing radial distance from the lumen of the pericardium seal towards the outside, the first sealing lip ( 52 ) and/or the second sealing lip ( 54 ) can exhibit increased flexibility. Increased flexibility at the edges of sealing lip ( 52 , 54 ) can strengthen the sealing properties of the sealing lip ( 52 , 54 ) and can also support the anatomically correct positioning of the sealing lip ( 52 , 54 ). Increased flexibility at the edges of the sealing lip ( 52 , 54 ) can be achieved through the choice of material. Each sealing lip ( 52 , 54 ) can be made of one material or of multiple materials. Reinforcements of a sealing lip ( 52 , 54 ) can be concentric reinforcements or radial reinforcements. Reinforcements can be achieved by means of variable material thicknesses or by introduction of a reinforcing material. The reinforcing material can be the same material as the base material of the sealing lip ( 52 , 54 ), having been converted into a different form of the material. Alternatively, regions, that are not to be reinforced can be weakened by converting the material of the sealing lip ( 52 , 54 ) into a weaker form of the material. A weakening of the material can be induced by exposure to energetic radiation (e.g., heat). Reinforcements of the material can also be achieved by application of material, whereby the applied material can be the same material as the base material of the sealing lip ( 52 , 54 ), or whereby the applied material can be a material different from the base material of the sealing lip ( 52 , 54 ). Suitable materials for the reinforcement of sections of a sealing lip ( 52 , 54 ) are metals, ceramics, rubber, or a combination thereof. [0080] One of the two sealing components ( 51 , 53 ) can exhibit a coupling mechanism, allowing the coupling of a sealing component ( 51 , 53 ) with the delivery system or a catheter of the delivery system. The coupling mechanism can consist, for example, of a cone ( 55 ) located at the first sealing component ( 51 ), onto which the delivery system or a catheter of a delivery system can be clamped. The clamping effect can be achieved by the diameter of the cone ( 55 ) being larger than the luminal diameter of the delivery system, for example. The coupling mechanism to couple the pericardium seal ( 5 ) to the delivery system can also be available at the second sealing component ( 53 ). The coupling mechanism can also be provided as a separate part in addition to the sealing components ( 51 , 53 ), and can link the delivery system to one of the two sealing components ( 51 , 53 ) of the pericardium seal ( 5 ). Other embodiments of the coupling mechanism may include, among others, a non-conical (e.g., cylindrical) extension on one of the sealing components ( 51 , 53 ), onto which the delivery system can be placed or glued. In some embodiments, the catheter of the delivery system and a sealing component form a single integrated part. In some embodiments, the catheter can after successful insertion and securing of the pericardium seal ( 5 ) be disconnected from the sealing component ( 51 , 53 ) or the pericardium seal ( 5 ) by means of a pre-weakened breaking point. [0081] One or both sealing components ( 51 , 53 ) can exhibit engaging components ( 57 ). These engaging components ( 57 ) can be used to apply a force to one or both sealing components ( 51 , 53 ) appropriate to couple and/or secure the sealing components ( 51 , 53 ). Engaging components ( 57 ) on one or on both sealing components ( 51 , 53 ) can be holes, indentations or elevations. The engaging components ( 57 ) can be installed around the circumference of the sealing component ( 51 , 53 ) at an equal distance from each other. The circumferential distance between the engaging components ( 57 ) can also vary. FIGS. 9 a - c illustrate six engaging components ( 57 ) equidistantly disposed around the circumference. On the ring-shaped sealing component ( 53 ), the six engaging components ( 57 ) are installed at an angular distance of approximately 60°. In the case of two, three, four, five, six, eight or more evenly distributed engaging components ( 57 ), the angular distance is 180°, 120°, 90°, 72°, 60°, 45° or less, respectively. The engaging components ( 57 ) can also be installed in an unevenly spaced configuration. [0082] FIG. 10 shows a pericardium seal ( 5 ) and a tool ( 11 ) to secure a pericardium seal ( 5 ). The pericardium seal ( 5 ) shown in FIG. 10 is essentially identical to the seal shown in FIG. 9 . As an example, the tool ( 11 ) is represented as an elongated tubular tool. Located at the distal end of the tool ( 11 ) are components ( 111 ), which can be at least partially engaged with the engaging components ( 57 ) of a sealing component ( 53 ). In the embodiment shown in FIG. 10 , the inside of the tubular tool ( 11 ) exhibits at the distal end six elevations ( 111 ) pointing to the inside, which can engage with the six engaging components ( 57 ) of the sealing component ( 53 ), for example, with six indentations on the sealing component ( 53 ). The tool ( 11 ) essentially exhibits the same number of components ( 11 ), which are complementary to the engaging components ( 57 ) of the sealing component ( 53 ). The tool ( 11 ) shown in FIG. 10 is a tubular tool, consisting of a complete tube. The tubular component of the tool ( 11 ) can also be half a tube, a quarter tube, or a third of a tube. In the extreme case, instead of the tube, only one shaft or multiple shafts can be attached to a distal, ring-shaped tool. A shaft can extend from the ring-shaped tool in longitudinal direction. A shaft can also extend laterally away from a longitudinal axis of the tool. Other embodiments of the tool ( 11 ) (not shown) can be provided in the form of a modified box wrench or a modified open-end wrench. [0083] FIG. 11 shows a connector system consisting of two connectors ( 90 , 92 ). The device for the support of the cardiac function includes a sheath with at least one sensor or at least one electrode and/or at least one expandable unit, whereby the sensor or electrode and/or the expandable unit are connected to a supply unit. The sensor or the electrode and/or the expandable unit can be directly connected to the supply unit. The sensor or the electrode and/or the expandable unit can be connected to the supply unit via a cable ( 4 ). The sensor or the electrode and/or the expandable unit can be directly linked to the supply unit via the cable ( 4 ), or the sensor or the electrode and/or the expandable unit can be connected to the supply unit. The supply unit can include a connector ( 92 ). The connector ( 92 ) can be attached directly to the supply unit. The connector ( 92 ) can be connected to the supply unit via a cable ( 4 ). The sensor or the electrode and/or the expandable unit can include a cable ( 4 ). At the end of the cable ( 4 ) can be a connector ( 90 ). The connector ( 90 ) at the end of the cable of the sensor or of the expandable unit matches the connector ( 92 ) at the supply unit. The connector ( 90 ) of the sensor or of the electrode and/or the expandable unit can be a male or a female connector. A female connector on the side of the sensor or the electrode and/or the expandable unit can be advantageous, since the female connector in contrast to the male connector does not include any pins ( 951 ) or any other terminals, which can protrude and therefore could break. If an exchange of the supply unit is required, the connector system is disconnected, and a new supply unit is connected to the connector ( 90 ) of the sensor or the electrode and/or the at least expandable unit. The reconnection of the connector ( 90 ) with a supply unit might cause pins ( 951 ) or other terminals to break. If the pins ( 951 ) or terminals are located in a male connector on the side of the sheath with the sensor or the at last one electrode and/or the expandable unit, an exchange of the sheath may be required. A female connector on the side of the sheath with the sensor or the electrode and/or the expandable unit can be advantageous, since the breaking of pins ( 951 ) or other terminals cannot occur at a female connector. The connector system ( 90 , 92 ) usually includes two connectors. The device according to the invention can consist of a connector system ( 90 , 92 ) for the sensor or the electrode and/or the expandable unit, or of multiple connector systems. If multiple connector systems are used, a connector system for electrical leads and a connector system for hydraulic and/or pneumatic lines can be provided. The connector system ( 90 , 92 ) represented in FIG. 11 is a connector system consisting of connections to supply the sensor or the electrode and the expandable unit. The number of connections depends on how many sensors or electrodes and how many expandable units are being used. In some implementations, the number does not necessarily have to correlate directly with the number of sensors or electrodes and/or the number of expandable units. Split leads/lines on both sides of the connector system ( 90 , 92 ) are possible, and a pneumatic or hydraulic line is configured to supply one, two, three, four, five, six or more fellable chambers. The filling of the multiple chambers by one line does not have to occur simultaneously; it can also occur individually by means of individually controllable valves. Likewise, one electrical lead inside the cable can be used for multiple sensors or electrodes, and switches can individually energize circuits. The connector system ( 90 , 92 ) represented in FIG. 11 includes four hydraulic or pneumatic connection ports ( 93 , 94 ) and one connection for electrical leads ( 95 , 96 ). The connecting port for electrical leads ( 95 , 96 ) shown in FIG. 11 exhibits 16 connecting components in the form of pins ( 951 ) and pin sockets ( 961 ). More or fewer connections for electrical leads ( 95 , 96 ) and/or pneumatic or hydraulic lines ( 93 , 94 ) can exist in one connector system. The pneumatic or hydraulic lines ( 93 , 94 ) can include one, two, three, four, five, six, seven, eight, nine or ten connections. [0084] The electric leads ( 95 , 96 ) can include one, two, three, four, five, six, seven, eight, nine, ten, twelve, fourteen, sixteen, twenty or more connections. One electrical connector for electric leads ( 95 , 96 ) can have one, two, three, four, five, six, seven, eight, nine, ten, twelve, fourteen, sixteen, twenty or more connecting components in the form of pins ( 951 ) and pin sockets ( 961 ). The number of connecting components in the form of pins ( 951 ) and pin sockets ( 961 ), however, is identical for the respective pair of connections for electricals leads ( 95 , 96 ). Each of the connections ( 93 , 94 , 95 , 96 ) in one or in both of the connectors of the connector systems ( 90 , 92 ) can have its own seal ( 931 , 952 ). The seal ( 931 , 952 ) of the individual connections ( 93 , 94 , 95 , 96 ) can be a sealing tape or a sealing gasket. The connector system ( 90 , 92 ) can in addition or only one seal inside the connector system ( 973 ) or around the connector system. A seal via the connector system can be a sealing tape or a sealing gasket. The connector parts ( 90 , 92 ) can be interconnected in order to create the connector system ( 90 , 92 ). The connector parts ( 90 , 92 ) can have a guide peg ( 972 ) and a guide slot ( 974 ). The guide peg ( 972 ) and the guide slot ( 974 ) can prevent wrong connection of the two connector parts and/or turning the connector parts the wrong way during connection. The connector parts ( 90 , 92 ) can also include two, three, or more guide pegs ( 972 ) and guide slots ( 974 ). In the case of two or more guide pegs ( 972 ) and guide slots ( 974 ), unequal distances between the individual guide pegs ( 972 ) and guide slots ( 974 ) can be used. The interconnected connector parts ( 90 , 92 ) can also be secured with a mechanism ( 971 ). Such mechanism ( 971 ) can be a screwing mechanism or a clamping mechanism or a bayonet catch. A mechanism to secure the interconnected connector system ( 90 , 92 ) can also be a retainer nut, a clamp, a latch or a snap-lock mechanism. Securing the connector system ( 90 , 92 ) is advantageous, since any accidental partial or complete disconnection of the connector system ( 90 , 92 ) can interrupt the supply of the sensor or the at least one electrode and/or the expandable unit. [0085] FIG. 12 shows a model for the preparation of a system of coordinates. The development of a system of coordinates can facilitate the manufacture of a device for the support of the cardiac function, since the position for the sensor or one electrode and/or the expandable unit and/or the marking can be exactly defined. FIG. 12 a shows a heart ( 61 ) with anatomical points of reference. The example illustrates the heart ( 61 ) with the aortic arch (AO) originating at the left ventricle (LV) (with head arteries, neck arteries, and subclavian arteries (TR, CL, SCL) branching off), and the pulmonary artery (PU) originating at the right ventricle (RV). Also shown are sections of the inferior vena cava (IVC) and the superior vena cava (SVC). The broken line ( 601 ) represents the height of the valve plane. The point ( 604 ) of the cardiac apex is defined by letting a perpendicular ( 603 ) fall from this plane ( 601 ) through the most distal point of the cardiac apex. The device according to the invention includes a sheath, into which a sleeve with at least one sensor or one electrode and/or a sleeve with at least one expandable unit can be inserted. The dimension of the sheath and/or the sleeve can be designed such that the upper edge of the sleeve ( 602 ) runs parallel to the valve plane with a downward offset in the direction of the cardiac apex at a distance from the valve plane of 1 mm to 30 mm, 3 mm to 20 mm, 5 mm to 10 mm, preferably 5 mm. The upper edge of the sheath is shown by the line ( 602 ) in FIG. 12 a . The lower edge of the sheath ( 605 ) and/or the sleeve can be parallel to the valve plane with a distance to the most distal point ( 604 ) of 1 mm to 30 mm, 3 mm to 20 mm, 5 mm to 10 mm, preferably 5 mm FIG. 12 b shows a cutting plane B-B along the line ( 602 ) shown in FIG. 12 a , i.e., along the line corresponding to the upper edge of the sheath. [0086] FIG. 12 b shows the right ventricular chamber (RV) and the left ventricular chamber (LV), the heart wall and the septal wall separating the cardiac chambers. The points ( 608 ) and ( 609 ) are defined as the points of intersection of the centerlines of the heart wall with the septal wall. The point ( 608 ) is also called the anterior intersecting point of the centerlines of the heart wall with the septal wall. The point ( 609 ) is also called the posterior intersecting point of the centerlines of the heart wall with the septal wall. The center point on a line connecting points ( 608 ) and ( 609 ) is defined as point ( 607 ). These points can be used to define a system of polar coordinates. The z-axis ( 606 ) of the polar coordinate system is defined as the line connecting the most distal point ( 604 ) to the center point ( 607 ) of the line connecting points ( 608 ) and ( 609 ). The circumferential direction of the coordinate system is suggested by the reference numeral ( 610 ) and defined as angle measure φ, whereby a line radially running from the z-axis ( 606 ) through the anterior point of intersection ( 608 ) is defined as φ=0°. [0087] FIG. 13 shows a sheath and/or sleeve with the coordinate system described above in conjunction with FIG. 12 . FIG. 13 a shows a 3D-model ( 611 ) of a sheath or sleeve with the z-axis ( 606 ) extending through the most distal point ( 604 ) and the center point ( 607 ) of the line connecting points ( 608 ) with ( 609 ). The points ( 608 ) and ( 609 ) are the anterior and the posterior point of intersection of the center lines of the heart wall with the septal wall, whereby the φ=0° line is drawn through the point ( 608 ). The broken line connecting the points ( 608 ) and ( 609 ) along an outer circumference of the sheath or the sleeve, represents the position of the septal wall of the heart as projected onto the sheath/sleeve. At the upper edge of the sheath or the sleeve, the angle measures starting at φ=0° are shown in 30° increments, whereby—viewed from above—the angles increase counterclockwise. Longitudinal lines ( 613 ) projected onto the sheath/sleeve respectively extend along these angles up to the cardiac apex ( 604 ). The angle measure of φ=360° then again corresponds to the angle measure of φ=0°. Contour lines ( 614 ) are indicated at distances of 15 mm increments. The contour lines ( 614 ) and planes are running perpendicular to the z-axis ( 606 ). The broken-dotted line ( 615 ) constitutes a cutting line, where the 3D shape ( 611 ) can be cut open and rolled out. FIG. 13 b shows a rolled-out sheath or sleeve ( 612 ), which has been cut along the line ( 615 ) in FIG. 13 a and then rolled out. The positions ( 608 , 609 ) and lines ( 613 , 614 , 615 , 616 ) shown in FIG. 13 b represent the same positions and lines that are shown in FIG. 13 a. [0088] FIG. 14 shows a sleeve ( 7 ) with at least one expandable unit ( 71 , 72 ). The 3D-shape of the sleeve ( 7 ) in FIG. 14 a is comparable to the 3D-model explained in conjunction with FIG. 13 a and shows a coordinate system as described above. The sleeve ( 7 ) can at least partially enclose a heart. The sleeve ( 7 ) can at least partially have the shape of a heart. The sleeve ( 7 ) can have a shape similar to the sheath. The sleeve can be inserted into the sheath. The sleeve can be made of synthetic material, polymer, natural rubber, rubber, latex, silicon or polyurethane. [0089] In FIG. 14 a , the sleeve ( 7 ) with at least one expandable unit ( 71 , 72 ) is shown as a sleeve ( 7 ) with a multiplicity of chambers. FIG. 14 b shows a 2D-rollout of the 3D-model from FIG. 14 a . The rollout represented in FIG. 14 b is essentially identical to the rollout of a 3D-model explained in conjunction with FIG. 13 b . Unlike in FIG. 13 a , the 3D-model in FIG. 14 a is rotated such that a view from above into the sleeve ( 7 ) is possible. In FIGS. 14 a and 14 b , four expandable units ( 71 , 72 ) are shown as examples, three of which are augmentation units ( 71 ) and one is a positioning unit ( 72 ). The expandable units ( 71 , 72 ) can be structurally similar but can serve different purposes, as described above. [0090] Generally, an augmentation unit ( 71 ) can be periodically expanded and relaxed in order to be configured to apply pressure to the heart. This pressure is preferably applied in ventricular areas. By applying pressure to a ventricle via the augmentation unit ( 71 ) the natural pumping motion of the heart is supported or substituted, and the blood inside the ventricular chamber is pumped into the corresponding artery. A pressure applied by an augmentation unit ( 71 ) to a right ventricle leads to the blood being ejected from the right ventricle into the pulmonary artery. A pressure applied by an augmentation unit ( 71 ) to a left ventricle leads to the blood being ejected from the left ventricle into the aorta. [0091] FIG. 14 shows three augmentation units ( 71 ), which are located at the upper edge of the sleeve ( 7 ). In this example, each of the augmentation units ( 71 ) is supplied by its own line ( 41 ). [0092] In the case of augmentation units ( 71 ) in the form of inflatable chamber, the lines ( 41 ) are preferably pneumatic or hydraulic lines. Other embodiments include one, two, three, four, five, six or more augmentation units ( 71 ), which are supplied by one, two, three, four, five, six or more lines ( 41 ). The line ( 41 ) can be made of synthetic material, polymer, natural rubber, rubber, latex, silicon, or polyurethane. The line ( 41 ) can run above, adjacent to or below the augmentation unit ( 71 ). The line ( 41 ) can preferably run below a positioning unit ( 72 ), so that no pressure points result between the line ( 41 ) and the heart wall. The line ( 41 ) can also run above or adjacent to a positioning unit ( 72 ). [0093] The augmentation units ( 71 ) A1, A2, and A3 shown in FIG. 14 are located in an area at the upper edge of the sleeve ( 7 ) and are each supplied by their own respective line ( 41 ). The augmentation units ( 71 ) A1 and A2 can—as illustrated in FIG. 14 —can be positioned such that they can assist a left ventricle. Augmentation unit ( 71 ) A3 is positioned to assist a right ventricle. The individual augmentation units ( 71 ) A1, A2 and A3 can be expanded individually. Augmentation units ( 71 ) A1 and A2 can assist cardiac function for a heart with left ventricular insufficiency. Augmentation unit ( 71 ) A3 can serve to support a right ventricular insufficiency. [0094] Augmentation units ( 71 ) A1, A2 and A3 can be used for support of a bilateral heart insufficiency. The augmentation units ( 71 ) can be expanded synchronously or asynchronously. Preferably, the expansion of the augmentation units ( 71 ) can be coordinated such that a natural pumping function of the heart is supported. [0095] A positioning unit ( 72 ) is a unit, which can also be expanded. Preferably, a positioning unit is expanded during operation of the device for the support of the cardiac function more statically than periodically. The positioning unit ( 72 ) can be expanded in order to fixate the device to the heart and to optimize the accuracy of the fit of the device. A positioning unit ( 72 ) can also help to respond to changes of the myocardium. If the size of the myocardium decreases or increases, a positioning unit can be expanded or relaxed further in order to ensure a perfect fit. [0096] FIG. 14 illustrates a positioning unit ( 72 ), which essentially fills the spaces between the three augmentation units ( 71 ) on the sleeve ( 7 ). The positioning unit ( 72 ) can have a distance from one or multiple augmentation units ( 71 ) of 1 mm, 3 mm, 5 mm, 10 mm, 20 mm, 30 mm, 40 mm or more. The positioning unit ( 72 ) can be supplied by its own line ( 41 ), in the case of a chamber fillable with a fluid, by a pneumatic or hydraulic line. Other embodiments include one, two, three, four, five, six or more positioning units ( 72 ), which are supplied by one, two, three, four, five, six or more pneumatic or hydraulic lines ( 41 ). The line ( 41 ) can consist of a synthetic material, polymer, natural rubber, rubber, latex, silicon or polyurethane. The line ( 41 ) for the supplying of the positioning unit ( 72 ) can run below the positioning unit ( 72 ). The positioning unit ( 72 ), shown in FIG. 14 , fills the spaces between the augmentation units ( 71 ). The depicted positioning unit ( 72 ) has extensions, which protrude into the spaces between the augmentation units ( 71 ). [0097] FIG. 15 shows an expandable unit ( 71 , 72 ) in the form of a chamber ( 710 ). The depicted chamber is a bellows-shaped chamber ( 710 ). A bellows-shaped chamber ( 710 ) has at least one section in the form of bellows. Preferably, chamber 710 is a folding bellows consisting of one, two, three, four, five, six, seven or more folds. An outwardly bent edge ( 711 ) can be defined as a fold. An inwardly bent edge ( 712 ) can be defined as a fold. In some embodiments, the regions of the chamber wall between the folds are less stable than the folds. One, multiple or all bent edges ( 711 , 712 ) can be reinforced. A reinforcement of a bent edge ( 711 , 712 ) is advantageous, since the bent edge ( 711 , 712 ) can be exposed to increased stress due to the expanding and relaxing of the chamber ( 710 ). A reinforcement of one or multiple bent edges ( 711 , 712 ) can reduce or prevent material fatigue along the bent edge ( 711 , 712 ). Reinforcement of a bent edge ( 711 , 712 ) can be achieved through a greater wall thickness of the material at the bent edge ( 711 , 712 ). A bent edge ( 711 , 712 ) can also be reinforced through application of additional material, wherein the applied material can be the same material as the underlying material, or wherein the applied material can be a different material than the underlying material. A chamber ( 710 ) can exhibit a top side ( 713 ), a bottom side and a side surface, whereby the side surface is preferably designed in the shape of a bellows. The top ( 713 ) and/or the bottom side can be oval, circular, elliptical, or polygonal. The top side ( 713 ) can have a different shape than the bottom side. [0098] A bellows-shaped chamber ( 710 ) can be inserted into a sheath of the type described above. The chamber ( 710 ) can be directly attached or fixated inside the sheath. The chamber ( 710 ) can be attached to structural components of the sheath, like, for example, a wire of a wire mesh, a strap of a latticework, or a structure on a sheath sleeve. [0099] The chamber ( 710 ) can be attached to crossing points of a mesh or latticework. The sheath can be covered by a membrane, as described above. In these cases, the chamber ( 710 ) can also be attached to the membrane. The membrane can also be a bottom side of the chamber ( 710 ). [0100] The bellows-shaped chamber ( 710 ) can also be fastened to a sleeve ( 7 ). Multiple bellows-shaped chambers ( 710 ) can be fastened to a sleeve ( 7 ). The sleeve ( 7 ) can at least partially have the shape of a heart. The sleeve ( 7 ) can have a shape similar to that of the sheath. The sleeve ( 7 ) can be inserted into the sheath. The sheath ( 7 ) can be fastened and/or fixated inside the sheath. The sleeve ( 7 ) can, in addition to one or multiple augmentation units like, for example, one or multiple bellows-shaped chambers ( 710 ), also exhibit one or multiple positioning units. The bottom side of the chamber ( 710 ) can be made of the same material as the sleeve ( 7 ). The sleeve ( 7 ) can be part of the chamber ( 710 ). The sleeve ( 7 ) can form the bottom side of the chamber. In those cases, only the lateral surfaces, which can be bellows-shaped, are applied to a sleeve ( 7 ). In addition, a top side ( 713 ) can be attached as well. The top side ( 713 ) can be a sleeve as well. Embodiments consist of two sleeves ( 7 ), whereby the sleeves ( 7 ) create the top side and the bottom side of the chambers, and lateral surfaces are formed between the sleeves. In this case, lateral surfaces can also be formed by joining, in particular by welding or gluing together of the two sleeves. The sleeves ( 7 ) can be joined together, in particular, welded or glued together, such that a chamber is formed. In some embodiments, the sleeves are connected to each other in a common edge region. In some embodiments, the chamber defines a gap of 0.1 mm to 5 mm. The line supplying the chamber can be formed similar to the chamber at least partially by joining the two sleeves ( 7 ), in particular by welding or gluing together of the two sleeves ( 7 ). Located on one of the two sleeves ( 7 ) or on both sleeves ( 7 ) can be one or multiple sensors or one or multiple electrodes. [0101] The sleeve ( 7 ) with the expandable unit can at the upper edge and/or at the lower edge exhibit at least one pocket. The pocket can be at least partially pulled over a structural shape of a sheath. The pocket can, for example, be at least partially pulled over a loop of a wire mesh or a strap of a latticework. [0102] The sleeve ( 7 ) with the expandable unit can contain an active agent. The sleeve ( 7 ) may, for example, contain an anti-thrombotic agent, an anti-proliferative agent, an anti-inflammatory agent, an anti-neoplastic agent, an anti-mitotic agent, an anti-microbial agent, a biofilm synthesis inhibitor, an antibiotic agent, an antibody, an anticoagulative agent, a cholesterol-lowering agent, a beta blocker, or a combination thereof. The agent is preferably provided in the form of a coating on the sleeve ( 7 ). The sleeve ( 7 ) can also be coated with extra-cellular matrix proteins, in particular, fibronectin or collagen. [0103] FIG. 16 shows a sleeve ( 80 ) with at least one sensor ( 81 ) and/or at least one electrode ( 82 ). The 3D-shape of the sleeve ( 80 ) in FIG. 16 a is comparable to the 3D-model described in FIG. 13 a and shows a coordinate system as described above. The sleeve ( 80 ) can at least partially enclose a heart. The sleeve ( 80 ) can at least partially have the shape of a heart. The sleeve ( 80 ) can have a shape similar to that of the sheath. The sleeve ( 80 ) can be inserted into the sheath. The sleeve ( 80 ) can be made of a synthetic material, polymer, natural rubber, rubber, latex, silicon or polyurethane. The sleeve ( 80 ) can exhibit a thickness of 0.1 mm to 1 mm, preferably 0.2 mm to 0.5 mm. The sleeve ( 80 ) with the sensor ( 81 ) and/or the electrode ( 82 ) can be pressed against the myocardium by the sleeve with the expandable units. The sleeve ( 80 ) can be coated, in particular, with a lubricant, which reduces the friction between the myocardium and the sleeve ( 80 ) with the sensor ( 81 ) and/or the electrode ( 82 ). A coating, in particular, a coating with a lubricant can also be provided between the sleeve ( 80 ) with the sensor ( 81 ) and/or the electrode ( 82 ) and the sleeve with the expandable unit. The sensor ( 81 ) and/or the electrode ( 82 ) can be worked, molded or welded into the sleeve ( 80 ) or attached, glued onto or sewn onto the sleeve ( 80 ). The sensor ( 81 ) and/or the electrode ( 82 ) can be equipped with reinforcements configured to prevent bending during the compression of the device. [0104] In FIG. 16 a , the sleeve ( 80 ) is depicted with at least one sensor ( 81 ) and/or at least one electrode ( 82 ) as a sleeve ( 80 ) with a multiplicity of sensors ( 81 ) and electrodes ( 82 ). FIG. 16 b shows a 2D-rollout of the 3D-model from FIG. 16 a . The rollout depicted in FIG. 16 b essentially matches the rollout of a 3D-model explained in conjunction with FIG. 13 b . Unlike in FIG. 13 a , the 3D-model in FIG. 16 a is rotated to allow a view from above into the sleeve ( 80 ). In FIGS. 16 a and 16 b , eight sensors ( 81 ) or electrodes ( 82 ) are shown as examples. Other embodiments can include one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve or more sensors ( 81 ) and/or electrodes ( 82 ). The sleeve ( 80 ) with the sensor ( 81 ) or at least one electrode ( 82 ) can be a net of sensors ( 81 ) or electrodes ( 82 ). The net of sensors ( 81 ) or electrodes ( 82 ) can at least partially enclose the heart. The sensors ( 81 ) or electrodes ( 82 ) in the net of sensors ( 81 ) or electrodes ( 82 ) can be interconnected. The sleeve ( 80 ) can function as the carrier of the net of sensors ( 81 ) or electrodes ( 82 ). The net of sensors ( 81 ) or electrodes ( 82 ) can also be only partially attached to a sleeve ( 80 ). The net of sensors ( 81 ) or electrodes ( 82 ) can also be inserted without a sleeve ( 80 ) into a sheath as the one described above. [0105] The sensor ( 81 ) or the electrode ( 82 ) can determine a physical or a chemical property of its environment. The property can be detected qualitatively or quantitatively. The sensor ( 81 ) can be an active sensor or a passive sensor. The sensor ( 81 ) can detect at least one parameter of the heart. The sensor ( 81 ) can be configured to determine the heart rate, the ventricular pressure, the systolic blood pressure, the diastolic blood pressure, pressure applied to a surface of the heart, fluid presence, acidity, electrical resistance, osmolarity, oxygen saturation or flow through a vessel. The sensor ( 81 ) can be configured to measure the pressure applied by an expandable unit onto a surface, the pH-value, the electric resistance, the osmolarity of a solution, or the flow through a vessel. The sensor can also be used as an electrode. [0106] The electrode ( 82 ) can be configured to electrically stimulate areas of the heart and/or to measure the action potential at the myocardium during the excitation process. The electrode ( 82 ) can be configured to stimulate the myocardium with the use of electrical impulses. An electrical stimulation can induce a myocardium to contract. The electrode ( 82 ) can be a pacemaker electrode. The electrode ( 82 ) can be an extra-cardial stimulation electrode. With an electrode ( 82 ), the myocardium can be stimulated before, during or after a support of the pumping function of the heart by a sheath with at least one expandable unit. The expansion of an expandable unit can occur before, during or after stimulation with an electrode ( 82 ). The device for the support of the cardiac function can be operated only with at least one expandable unit or only through stimulation with at least one electrode ( 82 ). Simultaneous operation of the expandable unit and the electrode ( 82 ) can be synchronous or asynchronous. The electrode can also be used a sensor. [0107] The sensor ( 81 ) or the electrode ( 82 ) can be fastened to the sleeve ( 80 ). The sensor ( 81 ) or the at least one electrode ( 82 ) can be glued, sewed or welded to the sleeve ( 80 ). The sensor ( 81 ) or the electrode ( 82 ) can be attached to the inside of the sleeve ( 80 ), preferably welded in. The sensor ( 81 ) or the electrode ( 82 ) can be connected via a lead ( 84 ) to a supply unit. The data detected by the sensor ( 81 ) or the electrode ( 82 ) can be transmitted connectionless via wireless technology, like bluetooth, for example. [0108] The contacts of the electrodes or sensors or the entire sleeve can be coated with a substance, which increases or improves conductivity. A graphite coating on the contacts, for example, can increase their conductivity. Example #1 [0109] FIG. 17 shows an embodiment of a sleeve ( 7 ) with at least one expandable unit ( 71 , 72 ). FIG. 17 depicts a 2D-rollout of a 3D-model described in conjunction with FIG. 13 . The illustrated sheath includes three augmentation units ( 71 ) (A1, A2, A3) and a positioning unit ( 72 ) (P). In some embodiments, the augmentation units A1 and A2 each occupy an area of 28.6 cm2 on the sleeve. The area occupied by augmentation unit A3 in this example is 34.5 cm2. The positioning unit ( 72 ) (P) occupies an area 114.5 cm2. Under normal conditions, the nominal expansion of the positioning unit (P) is 5 mm (e.g., the positioning unit is partially expanded and exhibits a thickness of 5 mm). The positioning unit can be a chamber, which can be filled and unfilled with a fluid. The thickness of the positioning unit can therefore be between 1 mm and 10 mm, preferably between 3 mm and 7 mm. By changing the thickness of the positioning unit ( 72 ) (P) an increase or decrease of the size of the heart can be compensated, and the correct fit of the sleeve ( 7 ) and/or the sheath essentially remains guaranteed. [0110] In this example, the thicknesses of augmentation units A1 and A2 can be expanded by about 1.9 cm in order to build up a pressure onto a ventricle (here, the left ventricle). The effective volume expansion of the augmentation units A1 and A2 in this example is 40 ml. The effective volume expansion of the augmentation unit A3 in this example is 50 ml and leads to an effective expansion of the thickness by 1.45 cm. Every corner of an augmentation unit can be described by the coordinates of the corner points (vertices). The coordinate system has been explained in conjunction with FIG. 13 . [0111] In this example, augmentation unit A1 extends from vertex 1 (φ=359″; z=100) via vertex 2 (φ=48″; z=85) and vertex 3 (φ=48″; z=40) to vertex 4 (φ=328″; z=56), and, in the implanted state, lies flat against the left ventricle. The connection of vertex 1 to vertex 2 essentially extends parallel to the upper edge of the sleeve ( 7 ) at a distance (d) of about 5 mm. The connection of vertex 2 to vertex 3 essentially extends along the φ=48° line. The connection of vertex 3 to vertex 4 essentially extends parallel to the upper edge of the sleeve ( 7 ) shown in the 3D-model. The connection of vertex 4 to vertex 1 essentially extends along the septal line ( 616 ). The corners of the augmentation unit A1 are rounded and describe a circular arc with a diameter of 4 mm. [0112] In this example, augmentation unit A2 extends from vertex 1 (φ=116′; z=69) via vertex 2 (φ=182″; z=74) and vertex 3 (φ=212″; z=37) to vertex 4 (φ=116″; z=26) and, in the implanted state, lies flat against the left ventricle. The connection of vertex 1 to vertex 2 essentially extends parallel to the upper edge of the sleeve ( 7 ) at a distance (d) of about 5 mm. The connection of vertex 2 to vertex 3 essentially extends along the septal line ( 616 ). The connection of vertex 3 to vertex 4 essentially extends parallel to the upper edge of the sleeve ( 7 ) shown in the 3D-model. [0113] The connection of vertex 4 to vertex 1 essentially extends along the φ=116° line. The corners of the augmentation unit A2 are rounded and describe a circular arc with a diameter of 4 mm. [0114] In this example, the augmentation unit A3 extends from vertex 1 (φ=235″; z=92) via vertex 2 (φ=303″; z=108) and vertex 3 (φ=303″; z=64) to vertex 4 (φ=235″; z=48) and, in the implanted state, lies flat against the right ventricle. The connection of vertex 1 to vertex 2 essentially extends parallel to the upper edge of the sleeve ( 7 ) at a distance (d) of about 5 mm. The connection of vertex 2 to vertex 3 essentially extends along the φ=303° line. The connection of vertex 3 to vertex 4 essentially extends parallel to the upper edge of the sleeve ( 7 ) shown in the 3D-model. The connection of vertex 4 to vertex 1 essentially extends along the φ=235° line. The corners of augmentation unit A3 are rounded and describe a circular arc with a diameter of 4 mm. [0115] The positioning unit P in the example of FIG. 17 is designed to essentially fill the spaces between the augmentation units ( 71 ) on the sleeve ( 7 ). The positioning unit ( 72 ) can also be described as a positioning unit ( 72 ) with extensions, which fill in the areas of the sleeve ( 7 ) that are not filled by the augmentation units. In this embodiment, the positioning unit P is essentially located at a lateral distance (d) from the augmentation units ( 71 ) and the upper edge of the sleeve ( 7 ) of about 5 mm. The positioning unit ( 72 ) is also located at a distance from the cutting line ( 615 ), which can be advantageous during manufacturing. If the sleeve ( 7 ) with the expandable unit is formed in a two-dimensional state, all augmentation units ( 71 ) and positioning units ( 72 ) can be attached to the sleeve ( 7 ) before the sleeve ( 7 ) is rolled into a three-dimensional form. [0116] In the example of FIG. 17 , the lines ( 41 ) supplying the expandable units ( 71 , 72 ) are hydraulic or pneumatic lines ( 41 ) extending radially from the lower edge of the sheath to the augmentation units. The line ( 41 ) for the augmentation unit A2 extends along the line φ=15° and ends at the height of z=54. The line ( 41 ) for augmentation unit A2 extends along the line φ=165° and ends at the height of z=31. The line ( 41 ) for augmentation unit A3 extends along the line φ=270° and ends at the height of z=65. The line ( 41 ) for the positioning unit P extends along the line φ=330° and ends at a height of z=25. Example #2 [0117] FIG. 18 shows an embodiment for a sleeve ( 80 ) with at least one sensor ( 81 ) and/or an electrode ( 82 ). Shown in FIG. 18 is a rollout as described in conjunction with FIG. 13 . The sleeve ( 80 ) of this embodiment includes eight sensors ( 81 ) or electrodes ( 82 ), whereby four of these are pressure sensors (force sensor FS1, FS2, FS3, FS4) ( 81 ), and four are electrocardiogram electrodes (e.g., ECG1, ECG2, ECG3, ECG4) ( 82 ). The sleeve ( 80 ) can be made of a synthetic material, polymer, natural rubber, rubber, latex, silicon or polyurethane. The sleeve ( 80 ) can have a thickness of 0.1 to 1 mm, preferably 0.2 mm to 0.5 mm. The four pressure sensors ( 81 ) can be integrated into the sleeve ( 80 ), for example, molded or welded to the inside surface of the sheath. The pressure sensors ( 81 ) can be equipped with reinforcements, which can prevent bending during the compression of the device. The ECG electrodes ( 82 ) can be attached at the side of sleeve ( 80 ) facing the heart. In the embodiment in FIG. 18 , a system of coordinates is depicted as described in conjunction with FIG. 13 . Using the coordinate system, the positions of the sensors ( 81 ) and electrodes ( 82 ) can be determined as follows: pressure sensor FS1 is located at coordinate (φ=17°; z=71), pressure sensor FS2 is located at coordinate (φ=158′; z=48), pressure sensor FS3 is located at coordinate (φ=268°; z=78), pressure sensor FS4 is located at coordinate (φ=67°; z=61). ECG electrode ECG1 is located at coordinate (φ=76°; z=54), ECG electrode ECG2 is located at coordinate (φ=352°; z=39), ECG electrode ECG3 is located at coordinate (φ=312°; z=93) and ECG electrode ECG4 is located at coordinate (φ=187°; z=18). For smaller or larger hearts, the angular coordinates for the sensors ( 81 ) and/or electrodes ( 82 ) essentially remain the same; while the z-value is scaled by a factor. For example, for smaller hearts, the scaling factor can be between 0.85 and 0.95, and for larger hearts, the scaling factor can be between 1.05 and 1.15.

A heart support system featuring a sheath sized to fit about at least a portion of an adult human heart in a living body, an expansion sleeve disposed within the sheath and sized to fit about the heart and a sensor sleeve disposed within the sheath and sized to fit about the heart. The expansion sleeve is at least partially defining an expandable chamber. The sensor sleeve carries at least one sensor electrically responsive to a heart parameter.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to input devices for computers and, in particular, to devices, systems and methods for facilitating positioning of a cursor on a display device of a computer-based system. 2. Description of the Related Art With the use of large and multi-head display devices becoming ever more prevalent, computer operators, such as graphic and CAD designers, for example, are experiencing difficulties interfacing with computer applications displayed on the display devices when utilizing conventional mouse-type input devices. More specifically, computer operators are finding it difficult to utilize the increased display area provided by the larger and multi-head displays without experiencing a characteristic of cursor movement about the display known as “mouse twitch” or “jump.” As utilized herein, “twitch” or “jump” is defined as the tendency of a mouse-driven cursor to move in a manner not desired by the operator. For instance, twitch may occur when the operator attempts to actuate a function of a mouse-type input device, such as by depressing an actuator or button of the mouse. Movement of the cursor during an actuation of a mouse function may occur when the cursor is in a location on the display device that is not designated by one of a predetermined number of grid points. For instance, when the cursor is located at a non-grid point and a mouse function is actuated, typically, the cursor will tend to move, i.e., twitch or jump, to the grid point closest to the cursor's current location. Movement of the cursor during an actuation of a mouse function also may occur due to inadvertent movement of the mouse during such actuation. Additionally, when an operator utilizes large or multi-head display devices, typically, the operator selects speed/sensitivity settings for the mouse that allow a small movement of the mouse to correspond to a relatively large movement of the associated cursor across the display area(s). However, many operations, such as CAD operations, oftentimes require the use of precise (small) cursor movements which are not easily accommodated by the aforementioned operator-selected speed/sensitivity settings of the mouse. Heretofore, in an effort to avoid mouse twitch or jump, computer operators typically change mouse speed and/or sensitivity settings for a mouse-type input device when switching between various computer applications and/or displays. Thus, it is not uncommon for a computer operator to switch mouse speed and/or sensitivity settings when switching from applications such as word processing, or other text-based applications, for example, to a graphic-based application, such as CAD, for instance, or even from one CAD function to another. However, since each change of mouse speed and/or sensitivity settings takes time, the efficiency of the computer operator may be reduced in proportion to the number of changes made. Therefore, there is a need for improved devices, systems and methods which address these and other shortcomings of the prior art. SUMMARY OF THE INVENTION Briefly described, the present invention relates to input devices for computers and, in particular, to devices, systems and methods for facilitating positioning of a cursor on a display device of a computer-based system. Such a computer-based system is adapted to facilitate operation of a computer application which is adapted to display a cursor within a display area of a display device of a computer. Typically, the computer includes a mouse-type input device for providing movement information and functional information corresponding to the cursor so that the cursor is movable about the display area in response to the movement information and is adapted to provide selected functionality in response to the functional information. In a preferred embodiment of the present invention, an input device is provided which includes a shifter configured to electrically communicate with the computer. The shifter is configured to enable functional information, provided by the mouse-type input device, to provide selected functionality of the cursor. The shifter also provides a shift-disable mode and a shift-enable mode so that, while in the shift-disable mode, the shifter enables the mouse-type input device to influence movement of the cursor on the display device. For instance, a movement of the mouse-type input device in a first direction and a first distance results in the cursor moving the first direction and a corresponding second distance. In the shift-enable mode, the shifter enables an altering of movement of the cursor so that movement of the mouse-type input device in the first direction and the first distance results in the cursor moving the first direction and a corresponding third distance, with the third distance being unequal to the second distance. In another embodiment, an input device is provided for interfacing with a computer application. Preferably, the input device includes: means for enabling functional information, provided by the mouse-type input device, to provide selected functionality of the cursor: means for enabling the mouse-type input device to influence movement of the cursor on the display device so that a movement of the mouse-type input device in a first direction and a first distance results in the cursor moving a corresponding second direction and second distance; and means for enabling an altering of movement of the cursor so that movement of the mouse-type input device in the first direction and the first distance results in the cursor moving the second direction and a corresponding third distance, with the third distance being unequal to the second distance. In another embodiment, a computer system for operating a computer application is provided. Preferably, the computer system includes a display device, a mouse-type input device and a shifter. In still another embodiment, a computer readable medium incorporating a computer program for interfacing with a computer application is provided. Preferably, the computer readable medium includes: logic configured to enable movement information, provided by the mouse-type input device, to influence movement of the cursor on the display device so that a movement of the mouse-type input device in a first direction and a first distance results in the cursor moving a corresponding second direction and second distance; logic configured to enable functional information, provided by the mouse-type input device, to provide selected functionality of the cursor; and logic configured to enable an altering of movement of the cursor so that movement of the mouse-type input device in the first direction and the first distance results in the cursor moving the second direction and a corresponding third distance, with the third distance being unequal to the second distance. Embodiments of the present invention also may be construed as providing methods for interfacing with a computer application. In a preferred embodiment, a method for interfacing with a computer application includes the steps of: enabling movement information provided by the mouse-type input device to influence movement of the cursor on the display device so that a movement of the mouse-type input device in a first direction and a first distance results in the cursor moving a corresponding second direction and second distance; enabling functional information, provided by the mouse-type input device, to provide selected functionality of the cursor; and enabling an altering of movement of the cursor so that movement of the mouse-type input device in the first direction and the first distance results in the cursor moving the second direction and a corresponding third distance, with the third distance being unequal to the second distance. Other features and advantages of the present invention will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such features and advantages be included herein within the scope of the present invention, as defined in the appended claims. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS The present invention, as defined in the claims, can be better understood with reference to the following drawings. The drawings are not necessarily to scale, emphasis instead being placed on clearly illustrating the principles of the present invention. FIG. 1 is a diagram depicting mouse twitch or jump. FIG. 2 is a schematic diagram depicting a processor-based system which may be utilized in implementing a preferred embodiment of the preferred invention. FIG. 3 is a high-level block diagram depicting a preferred method of the present invention. FIG. 4A is a schematic diagram depicting an embodiment of the present invention. FIG. 4B is a schematic diagram depicting an embodiment of the present invention. FIG. 5 is a schematic diagram depicting an embodiment of the present invention. FIG. 6 is a schematic diagram depicting an embodiment of the present invention. FIG. 7 is a schematic diagram depicting an embodiment of the present invention. FIG. 8 is a diagram depicting representative cursor movement facilitated by a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Reference will now be made in detail to the description of the invention as illustrated in the drawings with like numerals indicating like parts throughout the several views. As is known, a display device, e.g., a computer monitor, is configured for displaying graphical information provided by a processor-based system. For instance, a display device may be configured for presenting a computer application, such as a CAD application, to an operator. A representative depiction of a CAD application, as typically displayed on a display device, is shown in FIG. 1 . It should be noted that the preferred embodiments of the present invention described herein will be discussed, primarily, in relation to a CAD application, such as the application depicted in FIG. 1, for ease of description and not for purposes of limitation. Thus, the present invention may be utilized with numerous other applications incorporating the use of a mouse-driven cursor, as described in detail hereinafter, with such other applications being considered well within the scope of the present invention. As depicted in FIG. 1, CAD application 12 provides a computer operator with a grid network 14 formed of a series of horizontal rows 16 and a series of vertical columns 18 , with the grid network, oftentimes, being displayed to the operator. A plurality of predetermined points 20 are established at the intersections of the rows and columns, thereby providing the operator with grid-established points at which a cursor, such as cursor 22 , may be located when performing various functions provided by the application. The computer operator typically interfaces with the application by manipulating a mouse-type input device (not shown) that provides x and y coordinate data, corresponding to the movements of the mouse-type input device, as well as function-actuation data, corresponding to actuation of a “left-click” or “right-click” button, for example, to the processor-based system. The processor-based system then evaluates the various data and displays an appropriately positioned cursor 22 on the display. Thus, by moving the mouse-type input device and/or by actuating various actuators of the device, the computer operator may enable various application functionality at various locations about the display. As mentioned briefly hereinbefore, a cursor may present the operator with mouse twitch or jump. For instance, when the cursor 22 is displayed in position A (FIG. 1 ), which is defined by a point 20 of the grid network, and an actuator of the mouse-type input device is depressed or the mouse-type input device is inadvertently moved, the cursor may move without additional operator input to position B, which also is defined by a point 20 of the grid network. Thus, a zone 24 surrounds position B, whereby actuation of a mouse function while the cursor is displayed within the zone 24 results in the cursor moving to the center of that zone, e.g., the point 20 of the grid network. Likewise, a zone 26 surrounds position D, whereby actuation of a mouse function while the cursor is displayed within the zone 26 , such as when the cursor is being displayed at position C, results in the cursor moving to the center of zone 26 . If the computer operator desires to have the particular mouse functionality enabled at the location A, and not at position B which occupies the center of zone 24 , the operator typically must reset the mouse speed and/or sensitivity settings to an appropriate setting so that the position A may be appropriately and/or more conveniently recognized. As described in detail hereinafter, the present invention provides devices, systems and methods for repositioning the cursor (such as to position A) which, otherwise, typically is positioned by utilizing a mouse-type input device. As mentioned briefly hereinbefore, cursor movement may be facilitated by the present invention which, hereinafter, may be referred to as “the shifter,” “shifter system” and/or “method.” The shifter system of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In a preferred embodiment, however, the shifter system is implemented as a software package, which can be adaptable to run on different platforms and operating systems as shall be described further herein. In particular, a preferred embodiment of the shifter system, which comprises an ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device, and execute the instructions. In the context of this document, a “computer-readable medium” can be any means that can contain, store, communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer readable medium can be, for example, but not limited to, an electronic, magnetic, optical, electro-magnetic, infrared, or semi-conductor system, apparatus, device, or propagation medium. More specific examples (a nonexhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable, programmable, read-only memory (EPROM or Flash memory) (magnetic), an optical fiber (optical), and a portable compact disk read-only memory (CDROM) (optical). Note that the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory. FIG. 2 illustrates a typical computer or processor-based system 200 which may utilize the shifter system 100 of the present invention. As shown in FIG. 2, a computer system 200 generally comprises a processor 202 and a memory 204 with an operating system 206 . Herein, the memory 204 may be any combination of volatile and nonvolatile memory elements, such as random access memory or read only memory. The processor 202 accepts instructions and data from memory 204 over a local interface 208 , such as a bus(es). The system also includes an input device(s) 210 and an output device(s) 212 . Examples of input devices may include, but are not limited to a serial port, a scanner, or a local access network connection. Examples of output devices may include, but are not limited to, a video display, a Universal Serial Bus, or a printer port. Generally, this system may run any of a number of different platforms and operating systems, including, but not limited to, Windows NT™, Unix™, or Sun Solaris™ operating systems. The shifter system 100 of the present invention, the functions of which shall be described hereinafter, resides in memory 204 and is executed by the processor 202 . The flowchart of FIG. 3 shows the functionality and operation of a preferred implementation of the shifter system 100 depicted in FIG. 2 . In this regard, each block of the flow chart represents a module segment or portion of code which comprises one or more executable instructions for implementing the specified logical function or functions. It should also be noted that in some alternative implementations, the functions noted in the various blocks may occur out of the order depicted in FIG. 3 . For example, two blocks shown in succession in FIG. 3 may in fact be executed substantially concurrently where the blocks may sometimes be executed in the reverse order depending upon the functionality involved. As depicted in FIG. 3, the process preferably begins at block 302 where a determination is made as to where the shifter is enabled. If it is determined that the shifter is not enabled, the process preferably proceeds to block 304 where cursor speed/sensitivity defaults are facilitated. If, however, it is determined that shifter has been enabled, the process preferably proceeds to block 306 where mouse input, such as movement information and function information, for example, is received. At block 308 speed/sensitivity-modification input is received and then, such is depicted at block 310 , cursor speed/sensitivity is modified in a manner corresponding to the modification inputs received. After appropriate modification, the process preferably proceeds to block 312 , where a determination is made as to whether the shifter has been disabled. If it is determined that the shifter has not been disabled, the process preferably proceeds back to block 306 and then continues as described hereinbefore. If, however, it is determined that the shifter has been disabled, the process preferably returns to block 304 where a default cursor speed and sensitivity settings are once again facilitated. Thereafter, the process may return to block 302 and then proceed as described hereinbefore. Thus, alternating between the aforementioned enabled and disabled modes of the shifter allows an operator to conveniently alter the speed/sensitivity settings of the cursor between pre-established default settings and operator-modified settings. As depicted in FIG. 4A, a preferred embodiment 400 of the present invention incorporates the use of a shifter device 410 . Shifter device 410 is electrically interconnected intermediate of a mouse-type input device 412 and its associated computer system 414 , and preferably incorporates the use of one or more components or actuators (not shown) for “shifting” the device between the default and operator-modified cursor settings. Regardless of the particular configured utilized, the shifter device facilitates modification of cursor speed/sensitivity settings, thereby allowing a mouse-type input device to provide a more operator-friendly interface device. As depicted in FIG. 4B, an alternative embodiment 450 can use a keyboard to implement shifter functionality. In particular, keyboard 460 may utilize a user-specified key, e.g., key 470 , which has been remapped as a shifter enable key. Thus, after the keyboard has been remapped, actuation of the shifter enable key enables cursor speed/sensitivity settings to be shifted between default and operator-modified cursor settings. Referring now to FIG. 5, an alternative embodiment 500 also incorporates the use of a shifter device 510 . In contrast to the embodiment depicted in FIG. 4, however, system 500 incorporates the use of such a shifter device in a non-in-line arrangement. In particular, the shifter device 510 is configured to provide shifter data to the computer 514 via an interface device or switch box 516 which also is configured to receive input from the mouse-type input device 518 . So configured, the switch box facilitates interception and/or modification of movement information provided by the mouse-type input device, such as when a shifter-enable switch of the shifter device is actuated, for instance. Functional information provided by the mouse-type input device, however, is routed through the switch box and to the computer to facilitate various functionality provided by the mouse-type input device. Referring now to FIG. 6, an alternative embodiment 600 incorporates the use of a shifter device 610 which is configured to provide shifter data directly to a computer 614 . Preferably, the computer also is adapted to receive input from the mouse-type input device 616 . So configured, the movement information provided by the mouse-type input device may be modified by the computer in response to data received from the shifter, thereby allowing the shifter device to influence cursor location and movement, while functional information provided by the mouse-type input device continues to provide various mouse functionality. Such a configuration may be implemented by use of a software application, such as the application described in relation to FIG. 3, for instance. A preferred embodiment of an shifter device 700 of the present invention is depicted in FIG. 7 . As shown therein, shifter device includes a body 710 , primary actuators 712 and 714 , and a secondary actuator 716 . Preferably, actuators 712 and 714 are configured for providing conventional mouse functionality, such as “left-click” and “right-click” functions, respectively, and secondary actuator 716 provides shifter functionality, as described in detail hereinbefore. The actuators may be provided in numerous configurations and arrangements in order to fulfill their respective intended functions. It also should be noted that shifter device 700 is capable of providing cursor movement data to a computer in one of various conventional manners. Referring now to FIG. 8, the movement of a cursor, such as from location A to B1 (or C1) typically is facilitated by a corresponding movement, i.e., a movement characterized by a direction and a distance, of a mouse-type input device, e.g., device 700 being moved from A to B (or A to C). The shifter of the present invention may interface with a computer so that the same movement of the mouse-type input device allows the cursor to be moved to a different location on the display device. For instance, as depicted in FIG. 8, the shifter may allow the cursor to be moved from position A to B2 (or C2), with the same movement of the mouse-type input device described hereinbefore in relation to B1 and C1, respectively. When utilizing a shifter device, such as the shifter device 700 (FIG. 7 ), to facilitate the aforementioned cursor movements, the speed/sensitivity setting may be conveniently changed by actuating shifter-enable switch 716 by a simple movement of the thumb. The present invention accommodates numerous setting/sensitivity schemes, such as a single-click scheme, whereby a single, modified setting may be actuated by actuating a shift-enable switch, and a multi-click scheme, whereby multiple settings may be actuated by actuating a shift-enable switch an appropriate number of times, among others. The foregoing description has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment or embodiments discussed, however, were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations, are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly and legally entitled.

Devices, systems and methods for facilitating positioning of a cursor on a display device are provided. For example, an input device is provided which includes a shifter configured to electrically communicate with a computer. The shifter is configured to enable functional information, provided by a mouse-type input device, to provide selected functionality of the cursor. The shifter provides a shift-disable mode and a shift-enable mode so that, while in the shift-disable mode, the shifter enables the mouse-type input device to influence movement of the cursor on the display device. For instance, a movement of the mouse-type input device in a first direction and a first distance results in the cursor moving the first direction and a corresponding second distance. In the shift-enable mode, the shifter enables an altering of movement of the cursor so that movement of the mouse-type input device in the first direction and the first distance results in the cursor moving the first direction and a corresponding third distance, with the third distance being unequal to the second distance.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The invention relates to a device and method that enables Internet communication products to receive and send electronic voice mail, and more particularly, to a device and method that enables the sending and receiving of voice mail through the Internet, by means of a PDA, PC, notebook computer, or hand-held PC, for example. [0003] 2. Related Art [0004] Because of the rapid development of mobile phone industry and the promotion by the mobile communication service industry, cellular phone has been so popular that it is almost owned by everybody; utility model of cellular phone not only transmits each speaker's voice, but also possesses multimedia functions necessary for the new generation of cellular phone. Telecommunication suppliers not only provide the most basic 2-way voice transmission service, but also provide functions such as message, Web surfing, and even voice mailbox that frees both the receiver and the sender who fail to communicate with each other by voice instantly from the complicated process of keying in the text of a message to be sent. [0005] The voice mailbox usually carries out the recording, playing and storage of sounds by means of a telecommunication network and an ordinary voice telephone. For instance, under a mobile communication service system (e.g. GSM system), a sender can leave a voice message in a voice mailbox provided by a telecommunication supplier. However, the user has to pay an additional charge for using the voice mailbox. With an ordinary voice telephone system, a voice message can be left on a digital answering machine. [0006] Given the rapid development of Internet, Internet communication products such as PDA, PC, notebook or hand-held PC, which possess the function of Web linkage, but not the functions of cellular phone, have been popularized to a great extent. Although many Internet communication products nowadays can use built-in modem chip to receive and send email or browse Web page, most of them can only receive and send simple text files. As regards to PC, it possesses the most complete functions, enabling a user to receive and send, at the user's own choice, all kinds of multimedia messages or files, such as a voice document, to allow a friend at the receiver end to listen to a sender's greetings. Although all the other Internet communication products are equipped with modems (or modem chips) that have sound recording and playing functions, so far there has not been any known technology through which the functions of voice mailbox are enabled. SUMMARY OF THE INVENTION [0007] The primary object of the invention is to provide a device and method that enables Internet communication products to have the function of a voice mailbox. [0008] The method revealed by the present invention is aimed at, and designed for, those Internet communication products that merely possess Web linkage function, but do not have the functions of ordinary voice telephone. For instance, all PDA or hand-held PC that possesses Web linkage function may enable the function of voice mailbox through the technology of the present invention. [0009] The technology employed by the invention involves a voice message being picked up by a microphone of an Internet communication product. The voice message is then recorded by means of the sound recording function of the Internet communication product, resulting in the creation of a voice file. After that, a recipient's information and voice file are turned into a voice message packet that is then sent to a Web server via the Internet for storage. After connecting with the Web server via the Internet, the recipient may download from the Web server a corresponding voice message packet, which will be available to the recipient's Internet communication product. Eventually, the voice message is played by means of the voice playing function of the Internet communication product, so that the functions of a voice mailbox will be attained. [0010] The description of the detailed technology and embodiment of the present invention is made with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0011] The invention will become more fully understood from the detailed description given herein below. However, this description is for purposes of illustration only, and thus is not limitative of the invention, wherein: [0012] [0012]FIG. 1 is a diagram showing the systemic structure for the implementation of the invention. [0013] [0013]FIG. 2 shows the basic structure of Internet communication products. [0014] [0014]FIG. 3 is a diagram showing the structure of another embodiment of Internet communication products. [0015] [0015]FIG. 4 is the flowchart about the main steps of the method for the present invention. [0016] [0016]FIG. 5 is the flowchart about the embodiment for creating a voice message packet. [0017] [0017]FIG. 6 is the flowchart about the embodiment for sending a voice message packet. [0018] [0018]FIG. 7 is the flowchart about the embodiment for receiver's downloading a voice message packet. [0019] [0019]FIG. 8 is the flowchart about the embodiment for playing a voice message packet. [0020] [0020] 10a, 10b Internet communication products 11 Internet connection port 12 microphone 13 speaker 14 modem chip 15 microprocessor unit 151  Internet communication program 152  sound recording program 153  sound playing program 16 input unit 17 display unit 18 register 20 Web server DETAILED DESCRIPTION OF THE INVENTION [0021] First of all, see FIG. 1, which is a diagram showing the systemic structure of the present invention, comprising the following components that are linked together via Internet: [0022] A local Internet communication product 10 a that has the functions of sound recording and playing, and Internet linkage. This is the sender, and it produces a voice message packet; [0023] A Web server 20 , which is linked to Internet communication product 10 a by Internet, in order to allow the Internet communication product 10 a to upload and download voice message packets; and [0024] A remote Internet communication product 10 b that also has the functions of sound recording and playing, and Internet linkage. This is the recipient. After being linked to the Web server 20 over the Internet, it downloads the voice message packets stored in the Web server 20 , and it eventually plays the voice messages contained in the voice message packets. [0025] The foregoing Internet communication product 10 a, 10 b can either be a PDA, or a hand-held PC, equipped with the function of Web linkage. The basic structure of such an Internet communication product, as depicted in FIG. 2, comprises: [0026] An Internet connection port 11 , such as an RJ11 connector, for connecting to the Internet and thus creating an Internet communication path; [0027] A microphone 12 for picking up a user's message and converting it into an electrical signal; [0028] A speaker 13 for playing a voice message downloaded from the Internet; [0029] A modem chip 14 for linking to the Internet so as to facilitate the transmission and receipt of data; [0030] A register 18 for storing the data of a voice message by means of either RAM or flash memory; [0031] A microprocessor unit 15 , which comprises a built-in Internet communication program 151 , a built-in sound recording program 152 and a built-in sound-playing program 153 . The built-in Internet communication program 151 , when executed, enables the modem chip 14 to upload or download data via Internet. The built-in sound recording program 152 enables the modem chip 14 to start converting a voice message picked up by the microphone 12 into a voice file, and then storing the voice file in the register 18 . The built-in sound playing program 153 enables the modem chip 14 to start disassembling the voice message packets downloaded from the Web server 20 , and then playing the voice message through the speaker 13 ; and [0032] An input unit 16 , for example, a touch screen, keyboard, or both, that allows users to control the Internet communication product 10 a or 10 b in sending or receiving voice messages. [0033] Of course, the aforesaid Internet communication product 10 a , 10 b can also comprise a display unit 17 (see FIG. 3), for example a touch screen, a LCD or an indicator light. Such a display unit 17 is controlled by the microprocessor unit 15 , and its purpose is to display a prompt message so as to instruct a user to carry out the operation of the sound recording or the receipt of a voice message. [0034] Please continue to FIG. 4, which is a flow chart of the main steps of the method of the invention. It comprises: [0035] 1. The step of creating a voice message packet. It uses the sound recording function of the Internet communication products 10 a to turn sender's voice message and receiver's information (such as receiver's identification data or email address) into a voice message packet; [0036] 2. The step of sending a voice message packet. It uses the Internet communication function of the Internet communication product 10 a to send a voice message packet to a Web server 20 ; [0037] 3. The step of downloading a voice message packet. Receiver uses the Internet communication function of the Internet communication product 10 b to link up itself with a Web server 20 through Internet, and from the Web server 20 it downloads corresponding voice message packets to receiver's Internet communication product 10 b; and [0038] 4. The step of playing a voice message packet. It uses the sound playing function of the recipient's Internet communication product 10 b to disassemble and play the downloaded voice message packet. [0039] As shown in FIG. 5, the detailed procedures of the foregoing creation of a voice message packet are as follows: 1-1 Begin. It starts after a user has given a sound recording command through an input unit 16; 1-2 Start and initialize a modem chip 14. In other words, it starts the modem chip 14, and sends an initialization command to keep the modem chip 14 in a preparation status; 1-3 Set the modem chip 14 to the voice mode, for example, a micro- processor unit 15 sends a modem chip 14 a command, “AT#CLS = 8”; 1-4 Start the connection mode of microphone 12 and modem chip 14, for example, a microprocessor unit 15 sends a modem chip 14 a command, “AT# VLS = 3”; 1-5 Cause a display unit 17 to display a prompt message for starting sound recording (for example, a text message or a glittering light); 1-6 Start a sound recording program, and cause the modem chip 14 to convert the voice message picked up by the microphone 12 into a voice file that will then be stored in a register 18. For example, a microprocessor unit 15 sends a modem chip 14 a command, “AT# VRX”; 1-7 Create a voice message packet. Turn the sender's information (such as the recipient's identification data or email address) and voice file into a voice message packet and store the voice message packet in the register 18; and 1-8 End the generation of the voice message packet. [0040] As shown in FIG. 6, detailed embodiment procedures of sending a voice message packet are as follows: 2-1 Begin. It starts after a user has given a command through an input unit 16; 2-2 Connect with Internet; start a modem chip 14 so as to connect with Internet; 2-3 Connect with a Web server 20; 2-4 Upload a voice message packet to the Web server 20; and 2-5 End Internet connection. [0041] As shown in FIG. 7, the detailed procedures of the recipient downloading a voice message packet are as follows: 3-1 Begin. It starts after a user has given a command through an input unit 16; 3-2 Connect to the Internet; start a modem chip 14 so as to connect to the Internet; 3-3 Connect to a Web server 20; 3-4 Look for a voice message packet stored in the Web server 20; according to the default recipient's information-the search condition, go to the next step whenever a corresponding voice message packet is found, otherwise end the Internet connection; 3-5 Download the voice message packet stored in the Web server 20 and store it in a register 18; 3-6 Delete the voice message packet stored in the Web server 20; and 3-7 End the Internet connection. [0042] Of course, in the aforesaid steps 3-5, the identity of the recipients who download voice message packets can be scanned by means of identification and inspection, or through a safety procedure of encryption/decryption, so that only those recipients who pass the identification and inspection of identity can be allowed to download voice message packets. [0043] Finally, as shown in FIG. 8, detailed procedures about playing a voice message packet are as follows: 4-1 Begin. It starts after a user has given a playing command through an input unit 16; 4-2 Start and initialize a modem chip 14. In other words, it starts the modem chip 14, and sends an initialization command to keep the modem chip 14 in a preparation status; 4-3 Set the modem chip 14 to the voice mode, for example, a micro- processor unit 15 sends a modem chip 14 a command, “AT#CLS = 8”; 4-4 Start the connection mode of speaker 13 and modem chip 14, for example, a microprocessor unit 15 sends a modem chip 14 a command, “AT# VLS = 2”; 4-5 Cause a display unit 17 to display a prompt message about starting to play a voice message (for example, a text message or a glittering light); 4-6 Start a sound playing program, and cause the modem chip 14 to disassemble a voice message packet, that is, cause the modem chip 14 to disassemble the voice message packet downloaded from a Web server 20, and then play the voice message through speaker 13. For example, a microprocessor unit 15 sends a modem chip 14 a command, “AT# VTX”; and 4-7 End playing voice message. EFFECT OF THE INVENTION [0044] Making good use of the functions of sound recording, sound playing and Internet communication of Internet communication products, coupled with the Web servers of Internet, provide paths for receiving and sending voice messages as well as places for storing voice messages, so that Internet communication products that possess the function of Web linkage, but not the function of ordinary voice telephone, can gain access to the service of voice mailbox. [0045] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

A device and method that enables Internet communication products equipped with Web linkage functions to have the functions of a voice mailbox available only in general telecommunication systems or voice telephones through the multimedia service of the Internet. The invention uses the sound recording, playing functions and Internet communication of Internet communication products to turn voice data recorded and receiver's data into a voice message packet which is then sent to a Web server for storage, so that voice message can be retrieved from the voice mailbox when receiver's Internet communication products are linked to the Web server by Internet, to receive and send voice mail as well as use the voice mailbox.

TECHNICAL FIELD [0001] The present invention relates to a process for preparing a masterbatch comprising sulfur, more generally comprising a sulfur-based material, and carbon-based nanofillers, and also the masterbatch obtained in this way and the various uses thereof. Another subject of the invention is a solid composition comprising carbon-based nanofillers dispersed in a sulfur-based material. PRIOR ART [0002] Sulfur is very widely and commonly used in very numerous fields of industry, especially the chemical industry as synthesis reagent for the preparation of various chemical compounds, such as, for example, sulfuric acid, sulfur dioxide, oleums, carbon disulfide, sulfites or sulfates for the paper industry, or phosphorus pentasulfides as lubricant. [0003] Sulfur is also used as elemental sulfur of formula Ss, for the vulcanization of tires, as fungicide in agriculture, or as sulfur polymers for cement and concrete, or as heat transfer or storage fluid, especially for power stations (thermal or nuclear) or for solar panels, and also as active material for Li/S battery electrodes. [0004] An important raw material for elemental sulfur is hydrogen sulfide, recovered during the exploitation of natural gas deposits or by desulfurization of crude petroleum. Since reserves of natural gas tend to run out, elemental sulfur may be extracted directly by drilling into the Earth's crust, since sulfur is a relatively abundant nonmetallic element (only 0.06% of the Earth's crust, but readily extractable) and is non-toxic. [0005] The availability of the raw material makes it possible to envisage the large-scale and long-term development of uses of sulfur, in elemental form or in the form of sulfur-based material, in numerous fields of application. [0006] In some of these applications it may be advantageous to add carbon-based nanofillers such as carbon nanotubes (CNT) to the use of sulfur, in order to provide properties of electrical conductivity and/or mechanical properties. For example, it is envisaged to introduce carbon nanotubes to thermosetting elastomers before their vulcanization in order to produce reinforced tires, or else it is envisaged to add carbon nanotubes into formulations of electrodes for lithium-sulfur batteries in order to improve the kinetics of the electrochemical reactions involved. [0007] However, it has never been envisaged to directly introduce carbon nanotubes into sulfur, especially because CNTs prove difficult to handle and disperse because of their small size, their pulverulence and potentially, when they are obtained by chemical vapor deposition (CVD), their entangled structure which generates strong van der Waals interactions between their molecules. [0008] In document FR 2 948 233 a conductive composite material is described, obtained from a chemical treatment of sulfur and carbon, introduced into a sealed reactor without external regulation of the pressure within the reactor, at a temperature of between 115° C. and 400° C., for a sufficient amount of time to cause the sulfur to melt and equilibrium to be reached. This material is in the form of particles of sulfur covered with carbon having a low specific surface area. The process for introducing carbon into sulfur, described in this document, is only applicable to carbon-based nanofillers without form factor or aggregation. [0009] There therefore remains a need to have a means which makes it possible to simply and homogeneously disperse carbon nanotubes in elemental sulfur, in order to “dope” the sulfur to give it the mechanical and/or conductive properties necessary for the envisaged application. It would then be advantageous for the compounder to have a powder of sulfur comprising well dispersed CNTs, in the form of ready-to-use masterbatches. [0010] The applicant has discovered that this requirement could be met by carrying out a process comprising bringing CNTs into contact with elemental sulfur via the melt route in a compounding device, followed by transformation of the mixture obtained into a fine powder by conventional grinding techniques. [0011] It has moreover become apparent that this invention could also be applied to carbon-based nanofillers other than CNTs, in particular to carbon nanofibers, to graphene and to carbon black, or mixtures thereof in any proportions. [0012] In addition, the invention may more generally be applied to “sulfur donor” sulfur-based materials. SUMMARY OF THE INVENTION [0013] A subject of the invention is a process for preparing a masterbatch comprising from 0.01% to 50% by weight of carbon-based nanofillers, comprising: (a) introducing at least one sulfur-based material, carbon-based nanofillers, and optionally a rheology modifier into a compounding device; (b) melting the sulfur-based material; (c) kneading the molten sulfur-based material and the carbon-based nanofillers and optionally the rheology modifier; (d) recovering the mixture obtained in an agglomerated solid physical form; (e) optionally grinding the mixture into a powder. [0019] “Carbon-based nanofiller” denotes a filler comprising at least one element from the group formed of carbon nanotubes, carbon nanofibers, graphene, and carbon black, or a mixture thereof in any proportions. Preferably, the carbon-based nanofillers are carbon nanotubes, alone or in a mixture with graphene. [0020] “Sulfur-based material” is intended to mean elemental sulfur or “sulfur donor” compounds such as sulfur-based organic polymers or compounds and sulfur-based inorganic compounds such as anionic polysulfides of alkali metals. [0021] According to a preferred embodiment of the invention, elemental sulfur is used as the sulfur-based material, alone or in a mixture with at least one other sulfur-based material. [0022] Compounding devices have never been used to produce an intimate mixture of molten sulfur and carbon-based nanofillers. [0023] Sulfur is solid at room temperature and becomes liquid starting at 115° C. (melting point). [0024] One of the drawbacks of liquid sulfur is that its viscosity varies greatly, and non-linearly, as a function of the temperature. In order to overcome these drawbacks linked to the unstable viscosity, one of the technical restrictions of the compounding device is a relatively tight window for the melt process. The rheology of the loaded liquid sulfur must be controlled with perfect management of the process operating conditions, optionally using additives which reduce the viscosification above 140° C. [0025] The process according to the invention makes it possible to create homogeneous combining of the particles of carbon-based nanofillers with the sulfur, thereby giving it mechanical and/or conductive properties which are exploited in numerous applications. [0026] Another subject of the invention is the masterbatch able to be obtained according to the process described above. [0027] Another aspect of the invention relates to the use of the masterbatch as elastomer vulcanization agent for the manufacture of bodywork or sealing joints, tires, soundproofing plates, static charge dissipaters, internal conductive layers for high-voltage and medium-voltage cables, or antivibration systems such as motor vehicle shock absorbers, or in the manufacture of structural components for bullet-proof vests or as active material for the manufacture of electrodes for Li/S batteries or supercapacitors, without this list being limiting. [0028] The invention also deals with a solid composition comprising from 0.01 to 50% by weight, preferably from 1 to 30% by weight, of carbon-based nanofillers dispersed in a sulfur-based material, and also to the various uses thereof. BRIEF DESCRIPTION OF THE FIGURES [0029] FIG. 1 illustrates, on an SEM, the morphology of the S/CNT masterbatch obtained in example 1 according to the invention. [0030] FIG. 2 represents the particle size distribution of the powder obtained in example 1 according to the invention. [0031] FIG. 3 illustrates, by SEM, the homogeneous bulk morphology of a particle of the powder obtained in example 1 according to the invention. DETAILED DESCRIPTION OF THE INVENTION [0032] The invention is now described in greater detail and nonlimitingly in the following description. [0033] The process according to the invention is carried out in a compounding device. [0034] According to the invention, “compounding device” is intended to mean an apparatus conventionally used in the plastics industry for melt mixing thermoplastic polymers and additives with a view to producing composites. [0035] This type of apparatus has never been used for producing an intimate mixture of sulfur and/or of sulfur-based material and carbon-based nanofillers. In this apparatus, the sulfur-based material and the carbon-based nanofillers are mixed by means of a device with high shear, for example a co-rotating twin-screw extruder or a co-kneader. The molten material generally leaves the apparatus in an agglomerated solid physical form, for example in the form of granules, or in the form of rods which are cut into granules after cooling. [0036] Examples of co-kneaders which may be used according to the invention are the BUSS® MDK 46 co-kneaders and those of the BUSS® MKS or MX series, sold by BUSS AG, which all consist of a screw shaft provided with flights, placed in a heated barrel optionally made up of several parts, and the internal wall of which is provided with kneading teeth designed to cooperate with the flights so as to shear the kneaded material. The shaft is rotated, and given an oscillatory movement in the axial direction, by a motor. These co-kneaders may be equipped with a granulation system, for example fitted at their exit orifice, which may consist of an extrusion screw or a pump. [0037] The co-kneaders that may be used according to the invention preferably have an L/D screw ratio ranging from 7 to 22, for example from 10 to 20, whereas co-rotating extruders advantageously have an L/D ratio ranging from 15 to 56, for example from 20 to 50. [0038] In order to achieve optimal dispersion of the carbon-based nanofillers in the sulfur-based material in the compounding device, it is necessary to apply a large amount of mechanical energy, which is preferably greater than 0.05 kWh/kg of material. [0039] The compounding step is carried out at a temperature higher than the melting point of the sulfur-based material. In the case of elemental sulfur, the compounding temperature may range from 120° C. to 150° C. In the case of other types of sulfur-based material, the compounding temperature depends on the material specifically used, the melting point of which is generally given by the supplier of the material. The residence time will also be adapted to the nature of the sulfur-based material. [0040] The Sulfur-Based Material [0041] Various sources of elemental sulfur are commercially available. The particle size of the elemental sulfur powder may vary within wide limits. The elemental sulfur may be used as is, or the sulfur may be purified beforehand according to various techniques such as refining, sublimation or precipitation. [0042] The elemental sulfur or sulfur-based material may also be subjected to a preliminary stage of grinding and/or sieving in order to reduce the size of the particles and to narrow their distribution. [0043] Mention may be made, as sulfur-based materials chosen from sulfur-based organic polymers or compounds, of organic polysulfides, organic polythiolates including, for example, functional groups such as dithioacetal, dithioketal or trithioorthocarbonate, aromatic polysulfides, polyether-polysulfides, salts of polysulfide acids, thiosulfonates [—S(O) 2 —S—], thiosulfinates [—S(O)—S—], thiocarboxylates [—C(O)—S—], dithiocarboxylates [—RC(S)—S—], thiophosphates, thiophosphonates, thiocarbonates, organometallic polysulfides or mixtures thereof. [0044] Examples of such organosulfur-based compounds are especially described in document WO 2013/155038. [0045] According to the invention, use may be made, as sulfur-based material, of a sulfur-based inorganic compound, for example chosen from anionic polysulfides of alkali metals, such as lithium. [0046] According to a particular embodiment of the invention, the sulfur-based material is an aromatic polysulfide. [0047] Aromatic polysulfides correspond to the following general formula (I): [0000] [0048] in which: R 1 to R 9 represent, identically or differently, a hydrogen atom, an —OH or —O − M + radical, or a saturated or unsaturated carbon-based chain comprising from 1 to 20 carbon atoms, or an —OR 10 group, with Rio possibly being an alkyl, arylalkyl, acyl, carboxyalkoxy, alkyl ether, silyl or alkylsilyl radical comprising from 1 to 20 carbon atoms. M represents an alkali metal or alkaline earth metal, n and n′ are two integers which are identical or different, each being greater than or equal to 1 and less than or equal to 8, p is an integer between 0 and 50, and A is a nitrogen atom, a single bond or a saturated or unsaturated carbon-based chain of 1 to 20 carbon atoms. [0054] Preferably, in formula (I): R 1 , R 4 and R 7 are O − M + radicals, R 2 , R 5 and R 8 are hydrogen atoms, R 3 , R 6 and R 9 are saturated or unsaturated carbon-based chains comprising from 1 to 20 carbon atoms, preferably from 3 to 5 carbon atoms, the mean value of n and of n′ is approximately 2, the mean value of p is between 1 and 10, preferably between 3 and 8. (These mean values are calculated by those skilled in the art from proton NMR data and by assaying the sulfur by weight). A is a single bond connecting the sulfur atoms to the aromatic rings. [0061] Such poly(alkylphenol) polysulfides of formula (I) are known and may be prepared, for example, in two steps: [0062] 1) reaction of sulfur monochloride or dichloride with an alkylphenol, at a temperature of between 100 and 200° C., according to the following reaction: [0000] [0063] The compounds of formula (II) are especially sold by Arkema under the name Vultac®. [0064] 2) reaction of the compound (II) with a metal derivative comprising the metal M, such as, for example, an oxide, a hydroxide, an alkoxide or a dialkylamide of this metal, in order to obtain O − M + radicals. [0065] According to a more preferred variant, R is a tert-butyl or tert-pentyl radical. [0066] According to another preferred variant of the invention, use is made of a mixture of compounds of formula (I) in which 2 of the R radicals present on each aromatic unit are carbon-based chains comprising at least one tertiary carbon via which R is connected to the aromatic ring. [0067] The Carbon-Based Nanofillers [0068] The amount of carbon-based nanofillers represents from 0.01% to 50% by weight, preferably from 1% to 30% by weight, more preferentially from 5% to 25% by weight relative to the total weight of the masterbatch. [0069] According to the invention, the carbon-based nanofillers are carbon nanotubes, carbon nanofibers, graphene or carbon black or a mixture thereof in any proportions. The carbon-based nanofillers are preferably carbon nanotubes, alone or in a mixture with at least one other carbon-based conductive filler, preferably with graphene. [0070] The carbon nanotubes participating in the composition of the masterbatch may be of the single-walled, double-walled or multi-walled type. The double-walled nanotubes may especially be prepared as described by Flahaut et al. in Chem. Com. (2003), 1442. The multi-walled nanotubes may for their part be prepared as described in document WO 03/02456. [0071] The carbon nanotubes used according to the invention customarily have a mean diameter ranging from 0.1 to 200 nm, preferably from 0.1 to 100 nm, more preferentially from 0.4 to 50 nm and better still from 1 to 30 nm, or even from 10 to 15 nm, and advantageously have a length of more than 0.1 μm and advantageously from 0.1 to 20 μm, preferably from 0.1 to 10 μm, for example approximately 6 μm. Their length/diameter ratio is advantageously greater than 10 and most often greater than 100. These nanotubes thus especially comprise “VGCF” nanotubes (carbon fibers obtained by chemical vapor deposition or Vapor Grown Carbon Fibers). The specific surface area thereof is for example between 100 and 300 m 2 /g, advantageously between 200 and 300 m 2 /g, and the apparent density thereof may especially be between 0.01 and 0.5 g/cm 3 and more preferentially between 0.07 and 0.2 g/cm 3 . The multi-walled carbon nanotubes may for example comprise from 5 to 15 sheets and more preferentially from 7 to 10 sheets. [0072] These nanotubes may be treated or untreated. [0073] An example of crude carbon nanotubes is especially the tradename Graphistrength® C100 from Arkema. [0074] These nanotubes may be purified and/or treated (for example oxidized) and/or ground and/or functionalized. [0075] The grinding of the nanotubes may especially be carried out under cold conditions or under hot conditions and can be carried out according to the known techniques employed in apparatus such as ball, hammer, edge runner, knife or gas jet mills or any other grinding system capable of reducing the size of the entangled network of nanotubes. It is preferable for this grinding step to be carried out according to a gas jet grinding technique and in particular in an air jet mill. [0076] The crude or ground nanotubes can be purified by washing using a sulfuric acid solution, so as to free them from possible residual inorganic and metallic impurities, such as, for example, iron, originating from their preparation process. The weight ratio of the nanotubes to the sulfuric acid may especially be between 1:2 and 1:3. The purification operation can furthermore be carried out at a temperature ranging from 90° C. to 120° C., for example for a duration of 5 to 10 hours. This operation may advantageously be followed by steps in which the purified nanotubes are rinsed with water and dried. In a variant, the nanotubes may be purified by high-temperature heat treatment, typically at greater than 1000° C. [0077] The nanotubes are advantageously oxidized by bringing them into contact with a solution of sodium hypochlorite containing from 0.5 to 15% by weight of NaOCl and preferably from 1 to 10% by weight of NaOCl, for example in a weight ratio of the nanotubes to the sodium hypochlorite ranging from 1:0.1 to 1:1. The oxidation is advantageously carried out at a temperature of less than 60° C. and preferably at room temperature, for a duration ranging from a few minutes to 24 hours. This oxidation operation may advantageously be followed by steps in which the oxidized nanotubes are filtered and/or centrifuged, washed and dried. [0078] The nanotubes can be functionalized by grafting reactive units, such as vinyl monomers, to the surface of the nanotubes. The constituent material of the nanotubes is used as radical polymerization initiator after having been subjected to a heat treatment at more than 900° C., in an anhydrous medium devoid of oxygen, which is intended to remove the oxygen-comprising groups from its surface. It is thus possible to polymerize methyl methacrylate or hydroxyethyl methacrylate at the surface of carbon nanotubes. [0079] Use is preferably made in the present invention of optionally ground crude carbon nanotubes, that is to say nanotubes which are neither oxidized nor purified nor functionalized and which have not been subjected to any other chemical and/or heat treatment. [0080] Moreover, use is preferably made of carbon nanotubes obtained from a renewable starting material, in particular of plant origin, as described in Application FR 2 914 634. [0081] Carbon nanofibers are, like carbon nanotubes, nanofilaments produced by chemical vapor deposition (or CVD) starting from a carbon-based source which is decomposed on a catalyst comprising a transition metal (Fe, Ni, Co, Cu), in the presence of hydrogen, at temperatures of 500° C. to 1200° C. However, these two carbon-based fillers differ in their structure (I. Martin-Gullon et al., Carbon, 44 (2006), 1572-1580). This is because carbon nanotubes consist of one or more graphene sheets wound concentrically around the axis of the fiber to form a cylinder having a diameter of 10 to 100 nm. Conversely, carbon nanofibers are composed of more or less organized graphite regions (or turbostratic stacks), the planes of which are inclined at variable angles relative to the axis of the fiber. These stacks may take the form of platelets, fishbones or dishes stacked in order to form structures having a diameter generally ranging from 100 nm to 500 nm, or even more. [0082] Moreover, use is preferably made of carbon nanofibers having a diameter of 100 to 200 nm, for example of approximately 150 nm (VGCF® from Showa Denko), and advantageously a length of 100 to 200 μm. [0083] Graphene denotes a flat, isolated and separate graphite sheet but also, by extension, an assemblage comprising between one and a few tens of sheets and exhibiting a flat or more or less wavy structure. This definition thus encompasses FLGs (Few Layer Graphene), NGPs (Nanosized Graphene Plates), CNSs (Carbon NanoSheets) and GNRs (Graphene NanoRibbons). On the other hand, it excludes carbon nanotubes and nanofibers, which respectively consist of the winding of one or more graphene sheets coaxially and of the turbostratic stacking of these sheets. Furthermore, it is preferable for the graphene used according to the invention not to be subjected to an additional step of chemical oxidation or of functionalization. [0084] The graphene used according to the invention is obtained by chemical vapor deposition or CVD, preferably according to a process using a pulverulent catalyst based on a mixed oxide. It is characteristically in the form of particles having a thickness of less than 50 nm, preferably of less than 15 nm, more preferentially of less than 5 nm, and having lateral dimensions of less than a micron, preferably from 10 nm to less than 1000 nm, more preferably from 50 to 600 nm, or even from 100 to 400 nm. Each of these particles generally includes from 1 to 50 sheets, preferably from 1 to 20 sheets and more preferentially from 1 to 10 sheets, or even from 1 to 5 sheets, which are capable of being separated from one another in the form of independent sheets, for example during a treatment with ultrasound. [0085] Carbon black is a colloidal carbon-based material manufactured industrially by incomplete combustion of heavy petroleum products and which is in the form of carbon spheres and of aggregates of these spheres, the dimensions of which are generally between 10 and 1000 nm. [0086] The process according to the invention makes it possible to efficiently and homogeneously disperse a large amount of carbon-based nanofillers in the sulfur-based material. The carbon-based nanofillers are thus dispersed homogeneously throughout the mass of particles, and are not solely found at the surface of the sulfur-based particles as described in document FR 2 948 233. [0087] In addition, it is possible to add, during the compounding step, an additive which modifies the rheology of the sulfur-based material, such as sulfur in the molten state, in order to reduce the self-heating of the mixture in the compounding device. Such additives having a fluidizing effect on the liquid sulfur are described in Application WO 2013/178930. Mention may be made, by way of examples, of dimethyl sulfide, diethyl sulfide, dipropyl sulfide, dibutyl sulfide, dimethyl disulfide, diethyl disulfide, dipropyl disulfide, dibutyl disulfide, the trisulfide homologs thereof, the tetrasulfide homologs thereof, the pentasulfide homologs thereof, the hexasulfide homologs thereof, alone or in mixtures of two or more thereof in any proportions. [0088] The amount of rheology-modifying additive is generally between 0.01% to 5% by weight, preferably from 0.1% to 3% by weight relative to the total weight of the masterbatch. [0089] According to a particular aspect of the invention, at least one additive may be introduced into the compounding device. The nature of the additive will be adapted to the final use of the ready-to-use masterbatch. [0090] As additives, mention may for example be made of vulcanization accelerators or activators, lubricants, pigments, stabilizers, fillers or reinforcers, antistatic agents, fungicides, flame retardants, solvents, ionic conductors, or binders, without this list being limiting. [0091] At the outlet of the compounding device, the masterbatch is in the agglomerated physical form, for example in the form of granules. [0092] In a final step, the masterbatch may be subjected to a grinding step according to techniques well known to those skilled in the art, so as to obtain a masterbatch in powder form. Use may be made, as apparatus, of a hammer mill, a bead mill, an air jet mill or a planetary mixer. At the end of this stage, the desired median diameter D 50 will depend on the use of the masterbatch and is generally between 1 and 60 μm, preferably between 10 and 50 μm, preferably between 10 and 20 μm. [0093] At the end of the process according to the invention, a masterbatch is obtained having carbon-based nanofillers well dispersed in the mass of the particles. This morphology can be confirmed in particular by observation using a transmission electron microscope or a scanning electron microscope. [0094] The invention thus relates to a solid composition comprising from 0.01 to 50% by weight, preferably from 1 to 30% by weight, and more preferably from 5 to 25% by weight of carbon-based nanofillers dispersed in a sulfur-based material. [0095] The solid composition may also comprise at least one additive chosen from rheology modifiers, vulcanization accelerators or activators, lubricants, pigments, stabilizers, fillers or reinforcers, antistatic agents, fungicides, flame retardants, solvents, ionic conductors, or binders, or the combination thereof. [0096] The solid composition may be obtained according to the process described above and may be in powder form after grinding. The powder has particles with a median diameter D 50 of between 1 and 60 μm, preferably between 10 and 50 μm. [0097] The composition according to the invention is advantageously used for the manufacture of bodywork or sealing joints, tires, soundproofing plates, static charge dissipaters, internal conductive layers for high-voltage and medium-voltage cables, or antivibration systems such as motor vehicle shock absorbers, or in the manufacture of structural components for bullet-proof vests or for the manufacture of electrodes for Li/S batteries or supercapacitors. [0098] The masterbatch able to be obtained following the process according to the invention or the solid composition according to the invention may be used in conventional applications for sulfur, or more generally for sulfur-based materials, but it also makes it possible to develop novel applications which require mechanical reinforcement or electronic conductivity provided by the presence of carbon-based nanofillers within the sulfur-based material. [0099] The invention will now be illustrated by the following examples, the objective of which is not to limit the scope of the invention, defined by the appended claims. EXPERIMENTAL SECTION Example 1: Preparation of an S/CNT Masterbatch [0100] CNTs (Graphistrength® C100 from ARKEMA) and solid sulfur (50-800 μm) were introduced into the first feed hopper of a BUSS® MDK 46 (L/D=11) co-kneader fitted with a discharge extrusion screw and a granulation device. [0101] The temperature settings within the co-kneader were as follows: Zone 1: 140° C.; Zone 2: 130° C.; Screw: 120° C. [0102] At the outlet of the die, the masterbatch consisting of 85% by weight of sulfur and 15% by weight of CNT is in the form of granules obtained by pelletizing, cooled by a water jet. Observation by scanning electron microscope (SEM) showed that the CNTs were well dispersed in the sulfur ( FIG. 1 ). [0103] The granules obtained were dried to a moisture content <100 ppm. [0104] The dry granules were then ground in a hammer mill, cooling being provided by nitrogen. [0105] A powder with a D 50 of between 10 and 15 μm, and D100<50 μm, was obtained. FIG. 2 represents the particle size distribution of the powder and highlights the absence of particles larger than 50 μm in size, making it possible to avoid the formation of defects during the use of this powder for the production of cathodes for Li/S batteries. [0106] FIG. 3 uses scanning electron microscopy to show the homogeneous bulk morphology of a particle. [0107] This powder consisting of 85% by weight of sulfur and 15% by weight of CNT can be used, for example, for the preparation of an active material for electrodes for Li/S batteries, or of a base EPDM formulation for application in profiled elements in the automotive industry. Example 2: Preparation of an S/DMDS/CNT Masterbatch [0108] CNTs (Graphistrength® C100 from ARKEMA) and solid sulfur (50-800 μm) were introduced into the first feed hopper of a BUSS® MDK 46 (L/D=11) co-kneader fitted with a discharge extrusion screw and a granulation device. [0109] Liquid dimethyl disulfide (DMDS) was injected into the 1 st zone of the co-kneader. [0110] The temperature settings within the co-kneader were as follows: Zone 1: 140° C.; Zone 2: 130° C.; Screw: 120° C. [0111] At the outlet of the die, the masterbatch consisting of 78% by weight of sulfur, 2% by weight of DMDS and 20% by weight of CNT is in the form of granules obtained by pelletizing, cooled by a water jet. [0112] The granules obtained were dried to a moisture content <100 ppm. [0113] The dry granules were then ground in a hammer mill, cooling being provided by nitrogen. [0114] A powder having a median diameter D 50 of between 10 and 15 μm was obtained, which can be used for the preparation of an electrode for Li/S batteries. Example 3: Preparation of an S/Poly(Tert-Butylphenol) Disulfide/CNT Masterbatch [0115] CNTs (Graphistrength® C100 from ARKEMA) and solid sulfur (50-800 μm) were introduced into the first feed hopper of a BUSS® MDK 46 (L/D=11) co-kneader fitted with a discharge extrusion screw and a granulation device. [0116] Liquid dimethyl disulfide (DMDS) was injected into the 1 st zone of the co-kneader. [0117] The poly(tert-butylphenol) disulfide sold under the name VULTAC-TB7® from Arkema was premixed with an Li salt, sold under the name LOA (Lithium 4,5-dicyano-2-(trifluoromethyl)imidazole) by Arkema, then introduced into the first hopper by means of a 3 rd metering device. [0118] The temperature settings within the co-kneader were as follows: Zone 1: 140° C.; Zone 2: 130° C.; Screw: 120° C. [0119] At the outlet of the die, the mixture is in the form of granules obtained by pelletizing, cooled by a water jet. [0120] The granules obtained were dried to a moisture content <100 ppm. [0121] The dry granules were then ground in a hammer mill, cooling being provided by nitrogen. [0122] A powder consisting of 77% by weight of sulfur, 2% by weight of DMDS and 15% by weight of CNT, 5% of VULTAC-TB7°, 1% of LOA, having a D 50 of between 10 and 15 μm is obtained, which can be used for the preparation of an electrode for Li/S batteries. Example 4: Preparation of an S/Poly(Tert-Butylphenol) Disulfide/Stearic Acid/ZnO/CNT Masterbatch [0123] CNTs (Graphistrength® C100 from ARKEMA) were introduced into the first feed hopper of a BUSS® MDK 46 (L/D=11) co-kneader fitted with a discharge extrusion screw and a granulation device. [0124] The poly(tert-butylphenol) disulfide sold under the name VULTAC-TB7® from Arkema was premixed with solid sulfur and stearic acid and ZnO in powder form, then introduced into the first hopper by the second metering device. [0125] The temperature settings within the co-kneader were as follows: Zone 1: 140° C.; Zone 2: 130° C.; Screw: 120° C. [0126] At the outlet of the die, the masterbatch consisting by weight of 20% of sulfur, 20% of CNT, 20% of VULTAC TB7®, 15% of stearic acid and 25% of ZnO, is in the form of granules obtained by pelletizing, cooled by a water jet. [0127] The granules obtained were dried to a moisture content <100 ppm. [0128] This masterbatch may be used as vulcanization agent for the manufacture of motor vehicle shock absorbers.

The invention relates to a method for producing a master batch comprising between 0.01 and 50 wt. % of carbonaceous nanofillers and at least one sulphurated material such as elemental sulphur by melt compounding, and to the master batch thus produced and the different uses thereof. The invention also relates to a solid composition comprising carbonaceous nanofillers dispersed in a sulphurated material.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is related to U.S. patent application Ser. No. 12/942,248 filed Nov. 9, 2010 and entitled “Methods for Identifying the Guarantor of an Application,” to U.S. patent application Ser. No. 12/119,617 filed May 13, 2008 and entitled “Multi-Channel Multi-Factor Authentication,” now U.S. Pat. No. 8,006,291, and to U.S. patent application Ser. No. 12/137,129 filed Jun. 11, 2008 and entitled “Single-Channel Multi-Factor Authentication,” each of which is incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to the field of authentication and more particularly to the field of software distribution. [0004] 2. Related Art [0005] End-user-software-licensing policies implemented by software vendors pose challenges to users since end-user-software-licenses often are machine licenses. For instance, it is not uncommon for end-users to install software on a particular machine, enter a license-key and thereby activate the software. Vendors can limit the number of software activations by limiting the number of activations for any particular license-key. The activations are associated with the machines on which the software is installed, not the end-user. [0006] Many End-User-Software-License-Agreements (EULAs) specify that the end-user may install and use a vendors' software on a limited number of devices. For instance, Adobe® allows installation of some software products on two machines. Each of the installations on the two machines may be active simultaneously. A new activation of the software on a third machine requires the user to deactivate an installation of the software on at least one of the activated software installations. The number of activations is controlled through a network interface, commonly the Internet. [0007] In cases where a machine becomes inoperable or becomes unavailable, manual intervention by the vendor, license agent, or other entity controlling licenses is required to transfer a license to another operable machine. The procedure to allow users to transfer a license often involves revoking the current license and issuing a new license. The procedure for manually revoking licenses is expensive for vendors and inconvenient for licensed users. [0008] To circumvent these vendor software license policies, some users install and activate software on as many machines as authorized by a license, then call the vendor and falsely claim that one or more machines have been stolen, or failed, and that they require additional activations under their license, thereby pirating additional copies of the software. [0009] FIG. 1 schematically illustrates components used in a typical software license activation procedure according to the prior art. A user 100 obtains a software installation image, for example, via digital media 110 such as a CD ROM, DVD ROM, memory stick, etc. Alternatively, the user may obtain the software installation image via a network interface such as the Internet 120 from a file server such as an FTP server 130 . The software installation image is made available to the software installation platform, the machine on which the software installation image will be executed by the user 100 , for example, a PC 140 or smartphone 150 . [0010] After the software is installed from the installation image, it must be activated before it can be used long term. In many cases, vendors provide a grace period, during which the installed software can be used prior to activation. The grace period can provide the user 100 with an opportunity to try the software before activating it. The grace period can also allow users 100 to operate the software immediately in those cases where a network connection or telephone connection to the vendor's license authorization server 150 is not available to activate the software license. [0011] The software license activation procedure, whether or not a grace period is allowed, requires the user 100 to communicate a software license key 160 to a license authorization server 170 . The software license key 160 is also known as a software-installation-key in the art. Communication of the software license key 160 can be performed through the installed software, or over the phone 180 through an automated system or by vendor personnel. [0012] License authorization server 170 maintains a record of the number of activations available for each software license key 160 . When the license authorization server 170 receives an activation request including the software license key 160 , the license authorization server 170 determines whether any activations remain available and if so, the license authorization server 170 sends an activation code to the software installed on the platform 140 , 150 to fully activate the software. If no activations remain for the given license key 160 , the software is not activated. [0013] The user experience, when activating software for first time use, begins by obtaining a software installation image. The user 100 then starts the software installation, which will prompt the user 100 to provide the software license key 160 from a package or an e-mail, for example. The software license key 160 can be provided, as noted above, through the installation software on the platform 140 , 150 or through another channel such as over the phone, for instance. The user 100 then waits for the installation to complete, during which time the license authorization server 170 verifies the software license key 160 and provides an activation code. Once installation is complete, in many instances, the user 100 must activate the software license by accepting the terms. Then the software is fully functional on the platform 140 , 150 . [0014] In addition to tracking the numbers of remaining activations available for each software license key 160 , the license authorization server 170 can also store activation information in association with the activations that have already been used. Such information can identify the platform 140 , 150 , indicate a customer name, a location, an IP address, and so forth, and can be stored in databases, back-up storage, digital lockers associated with customer accounts, etc. [0015] The license authorization server 170 , during the activation process, commonly gathers information and in particular associates the software license key 160 with the platform 140 , 150 . There exist a number of methods for making this association including computing a machine signature that is sent to the license authorization server 170 , writing license key values (usually encrypted) to the local disk, broadcasting license information on the local subnet, writing activation data to registry databases on the local machine, making contact with a license server over the network, etc. [0016] For large organizations that license software for distribution to a large user population, the software license key 160 is distributed to users 100 to activate the software on their respective platforms 140 , 150 . The license authorization server 170 keeps an activation count for the particular software license key 160 until the limit set by the license is reached, after which no more activations are allowed. This procedure ultimately associates the software license with the platforms 140 , 150 on which activations were successfully completed. [0017] Another way that multiple activations for a license can be handled is with a local license server (not shown in FIG. 1 ). Each time a user 100 executes the software, a license is allocated from a pool of licenses. When the server license pool is empty, no further activations are allowed. Graceful exit of the software returns the license to the pool allowing another platform 140 , 150 to execute the software. [0018] A common method for associating a software license key 160 with a platform 140 , 150 when activating a standalone license is to use a computed machine signature to determine if the software is active. For instance, in some implementations a machine signature comprises, or is computed from, one or more hardware characteristics such as the Media Access Control (MAC) address of an onboard network card, a CPU serial number, a disk serial number, model, disk drive manufacturer, disk drive size, graphics adapter, etc. [0019] The machine signature mechanism prevents users 100 from cloning the disk drive, moving the clone to a second platform 140 , 150 and operating the software on the second platform 140 , 150 . An attempt to get an activated copy running from a cloned disk, for example, results in a request to activate the software since the CPU and disk drive characteristics do not result in a machine signature matching the first activation machine signature. [0020] Another strategy is a variation of the standalone activation just described. In this variant method a machine signature is computed and sent to the license authorization server 170 operated by the licensor. The machine signature is computed at activation time. Each time the software is started, the machine signature is verified. If the software is not activated, the software does not proceed. [0021] It is worth noting that verifying the activation each time the software is started simplifies transferring licenses. A user can install the software on any number of platforms 140 , 150 . Using an authentication procedure, usually a user name and password, a user 100 can de-activate the software on a particular platform 140 , 150 . Then the user 100 can activate the software on another platform 140 , 150 for immediate use. In this way the license can float, or more precisely be transferred to any platform 140 , 150 that the user 100 chooses. Once de-activated, the software cannot be used on the prior platform 140 , 150 , though it remains installed. [0022] The strategy of verifying the activation each time the software is started has a severe drawback, however. Since the signature of the platform 140 , 150 to be de-activated is only stored on the platform 140 , 150 , to which, it is associated, a machine failure results in the loss of the license. Thus, if the platform 140 , 150 fails while holding an activated license, there is no way to start the software to deactivate the license. [0023] Other license activation strategies exist. For instance, software can periodically broadcast messages on a Local Area Network (LAN) to determine if other instances of the software are running. If another is found, the first is disabled. Despite the various strategies in use, no existing licensing strategy associates the software license key 160 to the user 100 personally. Instead, software licensing and activations are associated with machines on which the software is installed or the network environment in which the software is executing, and based on authentication methods such as username/password that identify accounts. [0024] Using the most widely deployed software license activation practices not only leads to user inconvenience but it also facilitates software piracy. For example, the failure of a platform 140 , 150 requires a vendor to allow a user 100 to transfer a license to another. In many cases, license transfers are performed without verifying that a failure actually occurred. For a user 100 , an equipment failure is bad enough, and having to go through the vendor to transfer a license is a further inconvenience. For the vendor, the transfer usually requires staff intervention making the transfer an unwanted expense. However, for the software pirate, it is an easy way to obtain licenses for additional platforms 140 , 150 at low cost. SUMMARY [0025] The present invention provides methods for activating software on an installation platform such as a PC, smartphone, or tablet computer, and systems of one or more servers in communication with one another for implementing such methods. An exemplary method of the present invention comprises a step of receiving, with a first computing system, a software license key and first identifying information followed by a step of storing the software license key in association with the first identifying information, such as in a record of a database of a computer-readable memory. The receive software license key is encrypted in some embodiments, while in other embodiments the software license key and the first identifying information are contained within an encrypted envelope, and in some of these embodiments the software license key and the first identifying information are each separately encrypted as well. The first identifying information can comprise a machine signature and personal information, for example. In further embodiments, receiving the first software license key comprises receiving a hash of the first software license key. [0026] The exemplary method further comprises a step of receiving a first biometric sample, either with the same or a second computing system, and storing the first biometric sample as a biometric template in association with the software license key. The method additionally comprises a step of sending a first activation code from either computing system to the installation platform upon completion of the user enrollment. Examples of the first biometric sample include a voice sample and an image of the user. [0027] When the user wishes to transfer the license from one platform to another, the exemplary method further comprises, after sending the first activation code in the first instance, receiving the software license key and second identifying information, receiving a second biometric sample, matching the second biometric sample with the biometric template previously associated to the software license key, and then sending a second activation code. In some instances the first and second activation codes are the same. [0028] In systems of the present invention, the one or more servers include logic configured to perform the noted method steps. As used herein, “logic” means a physical system capable of carrying out a defined series of steps. Logic as used herein can form part of a server, or other computing system capable of serving multiple network connections, and can comprise application-specific integrated circuits (ASICs) specially designed to perform the series of steps, firmware programmed to perform the series of steps, a microprocessor in combination with software stored on a computer-readable medium specifying the series of steps, or any combination of these. It will be understood that logic as used herein specifically excludes software alone. Additionally, “computer-readable medium” as used herein specifically excludes paper and transitory media such as carrier waves. Systems of the present invention also comprise computer-readable media to maintain databases for data storage. [0029] Methods for activating software are also provided. An exemplary method, performed by a user, can comprise or consist essentially of installing an instance of the software on a platform and activating the instance on the platform by submitting a software license key and a biometric sample, and then receiving, with the installation platform, an activation code in response to submitting the biometric sample. The user can repeat this process with another platform to readily transfer the license to the other platform even when the software license agreement does not allow for additional activations. In such a situation a previously activated software instance on another platform is deactivated. BRIEF DESCRIPTION OF DRAWINGS [0030] FIG. 1 is a schematic representation of an exemplary system for activating licensed software according to the prior art. [0031] FIG. 2 is a schematic representation of an exemplary system for carrying out various methods described herein. [0032] FIG. 3 is a flowchart representation of a method for activating software according to an exemplary embodiment of the present invention. [0033] FIG. 4 is a flowchart representation of a further method for activating software according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION [0034] The present invention associates the activation of licensed software with the end-user 100 by employing biometrics identification technologies. Associating the user 100 with the software license fulfills the expectation of the user 100 and allows the vendor to enforce a licensing policy. The user 100 is associated with the software license by associating user biometrics with a software license key for the software license. Accordingly, the present invention better allows vendors to meet the expectations of End-User-License-Agreements (EULAs) that purport to allow users 100 to have control over where they install and use purchased software products. Further, the current invention prevents fraud by associating licenses with people rather than hardware that may or may not be active. [0035] FIG. 2 schematically illustrates components used in a software license activation procedure according to an exemplary embodiment of the present invention that associates a software license key 160 with a user 100 , a physical person, through the use of biometrics. Biometrics requires the user 100 to submit a sample of a particular biometric characteristic or behavior. Once submitted, the submitted sample is enrolled, meaning that it is associated with the user 100 , such as by association with a unique identifier such as a user ID or account number. The enrolled biometric reference sample can be compared to future submissions to identify or verify the identity of the person. For instance, a fingerprint can be used to automatically identify a person using a fingerprint scanner, computing equipment, and software. A user 100 submits an initial fingerprint sample by swiping a finger over the scanner and this sample is stored as a template for comparison. At a later time, the same user 100 can prove their identity by again swiping the finger. [0036] Biometric enrollment samples, and subsequent authentication samples submitted to prove identity, can be sent to a computing system of one or more servers, such as a license authorization server 170 and a biometrics authentication server 200 in communication with one another. Biometric samples for enrollment sent to the biometrics authentication server 200 are stored in association with the software license key 160 . The biometrics authentication server 200 identifies the user 100 (referred to as the claimant when seeking authentication) at a later time by comparing the enrolled biometric sample, saved as a template, with the subsequent biometric sample. If a biometric sample for a user 100 matches the stored biometric template from when the user 100 was enrolled, then the licensed software can be activated by the license authorization server 170 . Although biometrics authentication server 200 and license authorization server 170 are shown in FIG. 2 as separate servers, it will be understood that in some embodiments the functionality of both are integrated into a single server, while in other embodiments their functionalities are divided amongst additional servers. For example, enrollment can be handled by a third server (not shown). [0037] FIG. 3 is a flowchart representation of an exemplary method 300 of the present invention for activating software on an installation platform 140 , 150 . Steps of the activation method 300 can be performed, for example, by a software distributor through a license authorization server 170 and a biometrics authorization server 200 in communication with the installation platform 140 , 150 . The license authorization server 170 and the biometrics authorization server 200 can be the same server, in some embodiments. [0038] Initially, the user 100 installs licensed software from a software installation image, as described above. Once installed, the software is configured to not fully function, either immediately or following some grace period, until the software is activated. At this point the licensed software can prompt the user 100 to request activation, or the software can automatically continue the activation process. In either event, a first communication channel between the installation platform 140 , 150 and the license authorization server 170 is established, for example, by the licensed software. [0039] In a step 305 of the method 300 a software license key 160 and first identifying information are received by a first computing system such as the license authorization server 170 . Some or all of the software license key 160 and the first identifying information can be received over the first communication channel, such as the Internet or a local area network (LAN), while any balance of the software license key 160 and the first identifying information can be received over a second communication channel such as one between a phone 180 and license authorization server 170 . [0040] The software license key 160 can be a string of characters, either numeric or alpha-numeric, for example, XXXXX-XXXXX-XXXXX-XXXXX-XXXXX, where X is an alphanumeric character: A-Z or 0-9. Identifying information can include both information that identifies the installation platform 140 , 150 and information that identifies the user 100 . An example of information that identifies the installation platform 140 , 150 is a machine signature, while information that identifies the user 100 can include personal information such as a name, home address, e-mail address, phone number, and the like. In some embodiments the licensed software encrypts the software license key 160 before transmitting the software license key 160 to the first computing system. In further embodiments, the software license key 160 and the first identifying information are encrypted together resulting in an envelope that can be decrypted by the first computing system. In still further embodiments, the software license key 160 and/or the first identifying information are encrypted before being further encrypted together into the envelope. [0041] Hashing can also be used in the alternative to encryption. Hashing is distinguished in the art from encryption in that an encrypted element can be decrypted to render the original value. Hashing is an irreversible process such that a resultant hash cannot be analogously “unhanshed.” When two entities use the same hash algorithm on a same value the resulting hashes match. The hash can then be compared to determine a match without revealing the original value. [0042] In some instances, once activation is required, the licensed software will open a web browser on the platform 140 , 150 to allow the user 100 to complete the activation process with the license authorization server 170 . In some of these embodiments, the user 100 is prompted through the web browser to enter the software license key 160 , which may be printed on materials that came with the software installation image or may have been received by the user 100 in an e-mail or other electronic communication at the time of purchase. The user 100 can also be prompted to enter personal information. [0043] In some embodiments, the user 100 is asked to call a phone number for the license authorization server 170 , and once connected over the second communication channel to the license authorization server 170 , or a human operator in communication with the license authorization server 170 , the user 100 is prompted to enter the software license key 160 , either verbally or using a number pad on the phone 180 . The user may be enrolled using this second channel. In some of these embodiments the first identifying information can be sent over the first communication channel, while in other embodiments the licensed software encrypts the first identifying information with the software license key 160 and displays the resulting envelope to the user 100 ; the user 100 then is prompted to provide the resulting envelope to the license authorization server 170 over the second communication channel. [0044] In a step 310 of the method 300 the first identifying information is stored in association with the software license key 160 . For example, the first computing system can store the software license key and the first identifying information in a record of a database stored on non-volatile computer-readable medium. In some instances, the envelope itself is stored in association with the software license key 160 . [0045] In a step 315 the user 100 is enrolled. Enrollment entails a sub-step of receiving a first biometric sample from the user 100 with a second computing system and a sub-step of storing the first biometric sample as a biometric template in association with the software license key 160 . The second computing system can be a biometrics authorization server 200 or can be the same computing system as the first computing system. In those embodiments where the second computing system is different than the first computing system, a third communication channel can be established between the installation platform 140 , 150 and the second computing system. [0046] The first biometric sample can comprise a voice sample or an image of the user 100 , in various embodiments. For example, the second computing system can prompt the user 100 to say a word or phrase into a microphone of the platform 140 , 150 or can prompt the user 100 to face a video camera of the platform 140 , 150 . Various alternatives employing single or multiple factors and either a single or multiple communication channels are described in U.S. patent application Ser. Nos. 12/119,617 and 12/137,129 noted above. [0047] Once the first biometric sample has been received, the first biometric sample is stored as a biometric template in association with the software license key 160 . The biometric template can be added, for instance, to the record created previously for associating the software license key 160 with the first identifying information, or can be stored in a separate record in another database. The biometric template can be used in subsequent activation attempts to determine whether a person seeking to activate licensed software has previously been associated with the software license key 160 . [0048] In a step 320 of the method 300 an activation code is sent from the first computing system to the installation platform 140 , 150 upon completion of the user enrollment step 315 . In various embodiments the activation code is encrypted by the first computing system before being communicated to the installation platform 140 , 150 over the first communication channel. When the first computing system completes the enrollment, the first computing system can count an activation against the software license key 160 . This can be done by incrementing a counter associated with the software license key 160 , such as a counter associated with the record that associates the software license key 160 to the first identifying information. [0049] In some embodiments the counter is checked before the step 315 to determine whether the total number of activations granted under the terms of the EULA has been reached. In various embodiments checking the number of granted activations and the total allowed activations occurs in either step 305 or 310 . The method described with respect to FIG. 4 illustrates additional method steps that can be performed in such situations. [0050] Upon receipt of the activation code the licensed software on the platform 140 , 150 compares the received activation code against an expected value and unlocks the functionality of the licensed software if the two match. In some embodiments, the expected value is the encrypted activation code, and in these embodiments the received encrypted activation code does not have to be decrypted to make the comparison. [0051] When a user 100 starts previously activated software on a platform 140 , 150 , the software automatically calculates a machine signature and communicates the same to the license authorization server 170 , if possible. If the machine signature matches the machine signature last stored in association with the software license key 160 the license authorization server 170 takes no action and allows the instance of the software to continue. Otherwise, the lack of a match indicates either an attempted fraud or that the license had previously been transferred to another platform 140 , 150 and therefore the license authorization server 170 deactivates the instance of the software, optionally sending a message that the license was transferred to another platform 140 , 150 . In these situations an offer to purchase another activation can also be made. In various embodiments an envelope including the machine signature is sent and compared against the stored envelope. [0052] FIG. 4 illustrates a method 400 that optionally follows step 320 of method 300 . In a step 405 the first computing system again receives the software license key 160 over a first communications channel, but in association with different identifying information. This second identifying information can include different personal information or different machine signature, or both. The first computing system checks the record for the software license key 160 to determine whether the person seeking to activate the licensed software has previously activated the licensed software, and whether the number of activations equals the number of allowed activations. [0053] In the event that the number of allowed activations has not been equaled, and personal information for the person seeking to activate the licensed software does not match any personal information already stored in association with the software license key 160 , then the first computing system essentially repeats method 300 for the new user, having the new user also enroll in a step 315 , before issuing the activation key in a step 320 . If the number of allowed activations has been equaled, however, and the personal information for the person seeking to activate the licensed software does not match any personal information already stored in association with the software license key 160 , then the new user can be offered an opportunity to purchase an extension of the license in order to increase the number of allowed activations. [0054] If the number of allowed activations has been equaled, and the personal information for the person seeking to activate the licensed software matches the personal information for the user 100 stored in association with the software license key 160 , but the machine signature for the platform 140 , 150 is new, this indicates that the enrolled user 100 is seeking to activate the licensed software on a different platform 140 , 150 . In a step 410 of the method 400 , the first computing system stores the second identifying information in association with the software license key 160 as in step 310 of method 300 . [0055] In a step 415 the user 100 is authenticated. The user 100 is prompted to provide a second biometric sample which is received by the biometrics authorization server 200 . The second biometric sample is matched to the biometric template associated to the software license key 160 to demonstrate that the person seeking to activate the licensed software is actually the same person that was previously enrolled. If the second biometric sample matches the biometric template, then in a step 420 then the activation code is sent over the first communications channel and the new installation platform is activated. The activation code sent in step 420 is not necessarily the same as the activation code sent in step 320 , in some embodiments. For instance, activation codes can be time stamped to make each one different. [0056] It will be appreciated that the total number of activations will exceed the allowed number of activations when the activation code is sent in step 420 and some previously activated platform 140 , 150 will have to be deactivated unless, as above, additional activations are purchased. Thus, in a step 425 a previously activated platform 140 , 150 can be deactivated. Deactivation can be achieved by deleting a machine signature from the record for the software license key 160 , for example. The platform 140 , 150 that is deactivated in step 425 can be selected in a number of ways, with a particular manner specified in the EULA. for example, the first platform 140 , 150 associated with the software license key 160 can be the first to be deactivated, or the last platform 140 , 150 associated with the personal information of the user 100 can be deactivated, or the user 100 can be presented with a list of activated platforms 140 , 150 from which to select one to be deactivated. [0057] When activated licensed software on a platform 140 , 150 has been deactivated, in some embodiments, the licensed software will continue to function normally until that instance of the licensed software is shut down. In these embodiments, currently activated licensed software will connect to the license authorization server 170 upon start-up. If that instance has been marked for deactivation in the interim, the license authorization server 170 can deactivate the licensed software. [0058] In the foregoing specification, the invention is described with reference to specific embodiments thereof, but those skilled in the art will recognize that the invention is not limited thereto. Various features and aspects of the above-described invention may be used individually or jointly. Further, the invention can be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. The specification and drawings are, accordingly, to be regarded as illustrative rather than restrictive. It will be recognized that the terms “comprising,” “including,” and “having,” as used herein, are specifically intended to be read as open-ended terms of art.

Methods for software activation are provided that associate a software license key with one or more authorized individuals such that an authorized individual can readily transfer a license between different platforms. A biometric sample of the individual is stored in an enrollment step upon first activation of the software. Later, the same individual can provide a biometric sample that matches the stored biometric sample in order to activate the software on another platform, rendering the first instance inactive if no additional activations are available. More than one individual can be authorized under a license that allows for multiple activations.

TECHNICAL FIELD [0001] The inventive concept relates to a dental instrument, and more particularly, to a dental instrument for cutting soft tissue in the oral cavity to provide soft tissue used for a soft tissue transplantation surgery. BACKGROUND ART [0002] In general, a biomaterial may be divided into hard tissue and soft tissue. Bones or teeth are examples of the hard tissue. Skin, blood vessels, cartilages, or ligaments are examples of the soft tissue. The hard tissue has an elastic coefficient and a tensile strength that are higher than those of the soft tissue. [0003] The soft tissue as a biomaterial has been used in the field of dental treatment. In particular, soft tissue transplantation surgeries have been widely used as a method for rebuilding or treating damaged soft tissues during a dental surgery such as implant surgery. [0004] In case of an implant surgery that is recently in the limelight, gums around an implant need to be healthy so that a tooth implant may be used for a long time. This is the same principle that is used for a case in which a flag driven into sands. The flag does not fall when a large amount of sand exists around the flag. That is, even when an alveolar bone firmly holds the root of a tooth, the tooth may sway when the gum surrounding the tooth is insufficient. Also, exposed nerves may cause pain and it is not aesthetic. In this case, a soft tissue transplantation surgery is needed. [0005] To transplant soft tissues to an area where the thickness of a gum is thin or the gum is lost, soft tissue to be transplanted needs to be primarily obtained. To this end, soft tissues in an amount needed for transplantation are cut off from other normal area in the oral cavity. Typically, soft tissues in the palate of the oral cavity are used because the flesh of the palate is relatively thicker than that of other places. [0006] Dental instruments for cutting soft tissue are used to cut the soft tissue off from the oral cavity to provide soft tissue used for a soft tissue transplantation surgery. [0007] A conventional dental instrument for cutting soft tissue may include a main body equipped with a blade, a cover covering the upper portion of the main body, and a handle coupled to the main body and held by an operator. The blade is coupled to the main body by being separated therefrom to have a predetermined cutting depth. Also, the main body and the cover may be formed in a single body. [0008] In the meantime, soft tissue cut including the outer surface of a particular portion in the oral cavity may be used as the soft tissue to be transplanted in a portion having a thin thickness or in a place where gum is lost. However, it is advantageous to use soft tissue arranged at a predetermined depth under the outer surface of the particular portion in the oral cavity because of a high transplantation success rate. [0009] Since the conventional dental instrument for cutting soft tissue is equipped with a single blade having a predetermined cutting depth, to cut soft tissue arranged at a predetermined depth under the outer surface of the particular portion in the oral cavity, soft tissue is primarily cut by a predetermined depth under the outer surface and secondarily soft tissue by a desired thickness is cut off from the portion where the outer surface is removed. [0010] In addition, the cutting depth of a blade installed at a dental instrument for cutting soft tissue used for the first cutting process is different from that of a blade installed at a dental instrument for cutting soft tissue used for the second cutting process. Thus, two or more dental instruments for cutting soft tissue are needed for cutting soft tissue. Furthermore, when a single dental instrument for cutting soft tissue is in use, it is inconvenient to replace the blade for each process. DETAILED DESCRIPTION OF THE INVENTION Technical Problem [0011] The inventive concept provides a dental instrument for cutting soft tissue which may easily and simply cut soft tissue arranged at a predetermined depth under the outer surface in the oral cavity so that a soft tissue transplantation surgery may be facilitated. Advantageous Effects [0012] According to the present inventive concept, since the dental instrument for cutting soft tissue employs a dual blade structure of the first and second blades having different cutting depths, the soft tissue arranged at a predetermined depth under the outer surface in the oral cavity may be easily and simply cut so that a soft tissue transplantation surgery may be facilitated. BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIG. 1 illustrates the structure of a plasma processing apparatus according to an embodiment of the present invention; [0014] FIG. 2 is a perspective view of a gate value of FIG. 1 ; [0015] FIG. 3 is a partially cut perspective view of the gate valve taken along line III-III of FIG. 2 ; [0016] FIG. 4 is a perspective view of a cylinder of FIG. 2 during a normal operation; [0017] FIG. 5 is a perspective view of a cylinder of FIG. 2 during a maintenance and repair operation; and [0018] FIG. 6 is a perspective view of a locking pin of FIG. 4 BEST MODE FOR CARRYING OUT THE INVENTION [0019] According to an aspect of the inventive concept, there is provided a dental instrument for cutting soft tissue, which includes a main body in which an inlet hole through which cut soft tissue is input is formed, a blade provided at the main body, at least a portion of the blade being exposed to the outside through the inlet hole, and a cover covering an upper portion of the main body, wherein the blade includes a first blade having a first cutting depth, and a second blade provided adjacent to the first blade and having a second cutting depth smaller than the first cutting depth. [0020] The second blade may be arranged in front of the first blade with respect to a cutting direction. [0021] Each of the first and second blades may include a cutting portion where a blade surface is formed and exposed to the outside through the inlet hole, and a pair of wing portions bent and extending from both ends of the cutting portion and supported by the main body in the main body. [0022] To fix the position of the blade in the main body, a position fixing hole may be formed in each of the wing portions and a position fixing protrusion inserted in the position fixing hole may be formed in the main body. [0023] A position fixing recess engaged with the position fixing protrusion may be formed in the cover. [0024] An exhaust hole through which soft tissue input through the inlet hole is exhausted may be formed in the cover. [0025] A guide wall extending toward the inlet hole may be provided at a position adjacent to the exhaust hole to guide the soft tissue input through the inlet hole to the exhaust hole. [0026] The guide wall may be inclined with respect to a center line of the exhaust hole. [0027] A blade installation portion recessively formed in an area including the inlet hole may be provided at the main body, and a protruding portion protruding from an area including the exhaust hole to be engaged with the blade installation portion may be provided at the cover. [0028] The first and second blades may be either separately or integrally formed. [0029] The blade may be manufactured separately from the main body and coupled to the main body. [0030] The blade may be formed of metal and the main body is formed of plastic, and the blade may be integrally formed at the main body by injection molding. MODE FOR CARRYING OUT THE INVENTION [0031] The attached drawings for illustrating embodiments of the inventive concept are referred to in order to gain a sufficient understanding of the inventive concept and the merits thereof. [0032] Hereinafter, the inventive concept will be described in detail by explaining embodiments of the inventive concept with reference to the attached drawings. Like reference numerals in the drawings denote like elements. [0033] FIG. 1 is a perspective view of a dental instrument for cutting soft tissue according to an exemplary embodiment of the present inventive concept. FIG. 2 is an exploded perspective view of the dental instrument for cutting soft tissue of FIG. 1 . FIG. 3 is a rear perspective view of the cover of FIG. 2 . FIG. 4 is an enlarged perspective view of the blade of FIG. 2 . FIG. 5 is a side view illustrating a portion of the dental instrument for cutting soft tissue of FIG. 1 . FIG. 6 is a plan view of the dental instrument for cutting soft tissue of FIG. 1 . [0034] Referring to FIGS. 1 and 2 , a dental instrument 100 for cutting soft tissue (hereinafter, referred to as the dental instrument) according to an exemplary embodiment of the present inventive concept is a dental instrument for cutting soft tissue in the oral cavity, mainly, the soft tissue of the palate, to provide soft tissue used for a soft tissue transplantation surgery. The dental instrument 100 may include a main body 110 having blades 140 and 150 for cutting soft tissue in the oral cavity, a cover 120 covering the upper portion of the main body 110 , and a handle 130 extending long from the main body 110 to be held by an operator. [0035] In the present exemplary embodiment, the main body 110 , the cover 120 , and the handle 130 are formed of plastic that may be injection molded in consideration of manufacturing convenience and lightness. However, the material of the main body 110 , the cover 120 , and the handle 130 of the dental instrument according to the present inventive concept is not limited to plastic and other material such as metal may be used therefor. [0036] Referring to FIGS. 1-6 , an inlet hole 112 for guiding soft tissue cut by the blades 140 and 150 is formed in the main body 110 of the dental instrument 100 . A blade installation portion 114 in which the blades 140 and 150 are installed is recessively formed in an area including the inlet hole 112 . The blades 140 and 150 are installed at the blade installation portion 114 such that the center portions of the blades 140 and 150 may be exposed to the outside through the inlet hole 112 . [0037] The cover 120 of the dental instrument 100 is coupled to the main body 110 to cover the upper portion of the main body 110 . An exhaust hole 122 through which soft tissue input through the inlet hole 112 of the main body 110 is exhausted is formed in the cover 120 . In the present exemplary embodiment, the cover 120 is coupled to the main body 110 in a forced fit. To this end, a hook groove 126 formed at the leading end of the cover 120 is engaged with a hook step 116 formed at the leading end of the main body 110 . Also, a pair of insertion holes 128 in which a pair of insertion protrusions 118 formed at the rear end of the main body 110 are inserted are provided at the rear end of the cover 120 . An adhesive may be coated between the lower surface of the cover 120 and the upper surface of the main body 110 for a more firm coupling therebetween. [0038] However, in the present inventive concept, the coupling method between the cover 120 and the main body 110 is not limited to the above description and a variety of methods may be adopted instead. For example, the cover 120 may be hinge coupled to the main body 110 to open or close the upper portion of the main body 110 . In this case, the exhaust hole 122 through which soft tissue input through the inlet hole 112 of the main body 110 is exhausted may be omitted. [0039] That is, when the cover 120 is coupled to the main body 110 to open and close the upper portion of the main body 110 , a space defined by the main body 110 and the cover 120 may accommodate the cut soft tissue. Accordingly, even when the exhaust hole 122 is not formed in the cover 120 , the cut soft tissue may be taken out by opening the cover 120 . In addition, the cover 120 and the main body 110 may be integrally manufactured by injection molding. [0040] A protruding portion 124 protrudes from an area including the exhaust hole 122 to be engaged with the blade installation portion 114 of the main body 110 , as illustrated in FIGS. 2 and 3 . The protruding portion 124 of the cover 120 fixes the blades 140 and 150 by pressing both ends of the blades 140 and 150 installed at the blade installation portion 114 . Accordingly, the blades 140 and 150 may be stably fixed in the main body 110 so that movements particularly in upward and downward directions may be prevented. [0041] Also, a guide wall 129 is provided at the lower surface of the cover 120 by extending from a position adjacent to the leading end of the exhaust hole 122 toward the inlet hole 112 of the main body 110 , as illustrated in FIGS. 3 and 6 . The guide wall 129 guides the soft tissue input through the inlet hole 112 . The guide wall 129 is inclined with respect to the center line of the exhaust hole 122 , as illustrated in FIG. 3 . This is to facilitate the delivery of the cut soft tissue input through the inlet hole 112 to the exhaust hole 122 . Also, the guide wall 129 extends toward a position adjacent to the blades 140 and 150 exposed to the outside through the inlet hole 112 . This is to prevent the input of the soft tissue cut by the blades 140 and 150 through the inlet hole 112 and the escape of the soft tissue between the blades 140 and 150 and the lower surface of the main body 110 . [0042] Referring to FIGS. 1 and 2 , the handle 130 of the dental instrument 100 is a portion held by an operator during the cutting of the soft tissue in the oral cavity. The handle 130 is formed of the same plastic material as that used for the main body 110 and integrally formed with the main body 110 . In the present inventive concept, however, the handle 130 may be coupled to the main body 110 to be detachable in a screw coupling method, unlike the present exemplary embodiment. [0043] Referring to FIGS. 2-5 , the blades 140 and 150 installed at the main body 110 have a dual blade structure including the first blade 140 and the second blade 150 arranged adjacent to the first blade 140 . Both of the first and second blades 140 and 150 are formed of metal. The second blade 150 is arranged in front of the first blade 140 with respect to a cutting direction along an arrow of FIG. 5 . That is, with respect to the leading end of the main body 110 , the second blade 150 is arranged behind the first blade 140 . [0044] The first and second blades 140 and 150 respectively include cutting portions 142 and 152 exposed to the outside through the inlet hole 112 and having blade surfaces 141 and 151 , and a pair of wing portions 144 and 154 bent and extending from both ends of the butting portions 142 and 152 and supported by the blade installation portion 114 in the main body 110 . [0045] The cutting portions 142 and 152 are portions where the blade surfaces 141 and 151 are formed with respect to the cutting direction and have a shape of “␣” to be exposed to the outside through the inlet hole 112 . Also, the wing portions 144 and 154 are coupled to the main body 110 and horizontally bent and extending from both ends of the cutting portions 142 and 152 that are vertical to the lower surface of the main body 110 . The wing portions 144 and 154 are placed and supported on the blade installation portion 114 by being inserted in the main body 110 via the inlet hole 112 . The wing portions 144 and 154 placed and supported on the blade installation portion 114 are pressed and fixed by the protruding portion 124 of the cover 120 as described above. The blade surfaces 141 and 151 are inclined at a predetermined angle with respect to the cutting direction, as illustrated in FIG. 3 . This is to improve the cutting performance of the blade surfaces 141 and 151 . [0046] The first and second blades 140 and 150 having the above-described structure have a dual blade structure having different cutting depths H 1 and H 2 . That is, the cutting portion 142 of the first blade 140 is exposed to the outside through the inlet hole 112 so that the first blade 140 may have the first cutting depth H 1 . The cutting portion 152 of the second blade 150 is exposed to the outside through the inlet hole 112 so that the second blade 150 may have the second cutting depth H 2 . The cutting depth denotes a distance from the lower surface of the main body 110 to the blade surface 141 or 151 , which determines the thickness of the soft tissue cut during the soft tissue cutting. [0047] As described above, the soft tissue transplantation surgery in the dental field denotes a surgery of cutting a desired amount of soft tissue off from a particular portion, mainly, the palate, in the oral cavity, and transplant the cut soft tissue in a gum, when the thickness of a gum around a portion where an implant is placed is thin or the gum is insufficient. Although the cut soft tissue including the outer surface of the particular portion in the oral cavity may be used as soft tissue to be transplanted in the gum that is thin or lost, soft tissue arranged at a predetermined depth under the outer surface of the particular portion in the oral cavity is used because of its high transplantation success rate. [0048] However, since a conventional dental instrument for cutting soft tissue is equipped with a single blade having a predetermined cutting depth, to cut soft tissue arranged at a predetermined depth under the outer surface of the particular portion in the oral cavity, soft tissue at a predetermined depth under the outer surface is primarily cut and secondly soft tissue of a desired thickness is cut off from a portion where the outer surface is removed. These processes are inconvenient. [0049] Also, since the cutting depths of a blade installed at a dental instrument used for the first cutting process and a blade installed at a dental instrument used for the second cutting process are different from each other, two or more dental instruments are needed for cutting the soft tissues in the soft tissue cutting processes. Furthermore, when a single dental instrument is used to cut soft tissue, it is inconvenient to replace the blade for each process. [0050] To solve the above inconvenience generated when the conventional dental instrument is in use, the dental instrument 100 according to the present exemplary embodiment has a dual blade structure of the first blade 140 and the second blade 150 having the different cutting depths H 1 and H 2 so that the soft tissue transplantation surgery may be facilitated. [0051] That is, in the dental instrument 100 according to the present exemplary embodiment, since the second blade 150 having the cutting depth H 2 smaller than the cutting depth H 1 of the first blade 140 is arranged in front of the first blade 140 with respect to the cutting direction, the soft tissue arranged at a predetermined depth under the outer surface of the particular portion in the oral cavity may be cut in a single cutting process. [0052] In detail, when an operator cuts soft tissue off from the particular portion in the oral cavity using the dental instrument 100 according to the present exemplary embodiment, the soft tissue is cut by the first blade 140 to a thickness corresponding to the second cutting depth H 2 off from the outer surface of the particular portion. The upper and lower surfaces of the soft tissue arranged at a predetermined depth under the outer surface of the particular portion are respectively cut by the second blade 150 and the first blade 140 so that the cut soft tissue is input between the first and second blades 140 and 150 . [0053] Accordingly, when soft tissue is cut off from the particular portion in the oral cavity by using the dental instrument 100 according to the present exemplary embodiment, the soft tissue arranged at a predetermined depth under the outer surface of the particular portion in the oral cavity may be cut by using a dental instrument equipped with blades having different cutting depths or by not replacing the blade. [0054] The first and second blades 140 and 150 may be installed separately, but close to each other, at the blade installation portion 114 of the main body 110 . Alternatively, the first and second blades 140 and 150 may be integrally formed and installed at the blade installation portion 114 of the main body 110 . The first and second blades 140 and 150 may be manufactured by performing cutting and bending processes to a blade having a long plate shape. In terms of manufacturing convenience, the first and second blades 140 and 150 may be separately formed. In terms of assembly convenience and stability, the first and second blades 140 and 150 may be integrally formed. Also, when the first and second blades 140 and 150 are separately formed, the first and second blades 140 and 150 are installed at the main body 110 by being in contact with each other or slightly separated from each other. [0055] Also, as described above, the positions of the first and second blades 140 and 150 may be fixed in the main body 110 as the blade installation portion 114 recessively formed in the main body 110 and the protruding portion 124 protruding from the cover 120 are pressed to contact each other with the wing portions 144 and 154 of the first and second blades 140 and 150 interposed therebetween. For more firm position fixing, in the present exemplary embodiment, position fixing holes 145 and 155 are formed in the wing portions 144 and 154 of the first and second blades 140 and 150 and position fixing protrusions 115 inserted in the position fixing holes 145 and 155 are formed on the blade installation portion 114 of the main body 110 . Also, position fixing recesses 125 engaged with the position fixing protrusions 115 are formed in the protruding portion 124 of the cover 120 . [0056] In the present exemplary embodiment in which the first and second blades 140 and 150 are separately formed, the position fixing holes 145 and 155 are respectively formed at the first and second blades 140 and 150 . Accordingly, the position fixing protrusions 115 and the position fixing recesses 125 are respectively formed at four positions of each of the blade installation portion 114 and the protruding portion 124 . In the present inventive concept, the shape, position, and number of the position fixing protrusions and the position fixing holes are not limited to the above descriptions. [0057] Accordingly, the positions of the first and second blades 140 and 150 are stably fixed in the main body 110 . In particular, the first and second blades 140 and 150 may be prevented from being twisted at the fixed positions during the cutting of soft tissue. In addition, according to the above-described blade position fixing structure according to the present exemplary embodiment, the determination of the positions of the first and second blades 140 and 150 in the process of assembling the first and second blades 140 and 150 and the cover 120 to the main body 110 is made easy so that assembly convenience may be improved. [0058] Also, in the present exemplary embodiment, the first and second blades 140 and 150 formed of metal are manufactured separately from the main body 110 formed of plastic. However, the first and second blades 140 and 150 formed of metal may be integrally formed by injection molding with the main body 110 formed of plastic. That is, the coupling method of the first and second blades 140 and 150 and the main body 110 is not limited to the above-described method. [0059] As described above, according to the present inventive concept, since the dental instrument for cutting soft tissue employs a dual blade structure of the first and second blades having different cutting depths, the soft tissue arranged at a predetermined depth under the outer surface in the oral cavity may be easily and simply cut so that a soft tissue transplantation surgery may be facilitated. [0060] While the inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the following claims. INDUSTRIAL APPLICABILITY [0061] The present inventive concept can be applied to the technical field of a dental instrument for cutting soft tissue in the oral cavity.

Disclosed is a dental instrument for cutting soft tissue. The dental instrument for cutting soft tissue according to the present invention includes: a main body having an inlet portion for inserting soft tissue to be cut into the main body; a cutter blade arranged in the main body such that at least a part of the cutter blade is exposed outwardly through the inlet portion; and a lid for covering the upper portion of the main body. The cutter blade includes a first cutter blade having a first cut depth, and a second cutter blade arranged in the vicinity of the first cutter blade, and which has a second cut depth shallower than the first cut depth. The dental instrument of the present invention makes it possible to cut the soft tissue in the deep part of a mouth in an easy and simple process, thereby improving the convenience of soft tissue implantation.

PRIORITY This application claims priority from co-pending provisional U.S. Patent Application Ser. No. 60/147,668, filed Aug. 6, 1999, entitled “GRAPHICS WORKSTATION” and bearing, the disclosure of which is incorporated herein, in its entirety, by reference and co-pending provisional U.S. Patent Application Ser. No. 60/147,609, filed Aug. 6, 1999, entitled “DATA PACKER FOR GRAPHICAL WORKSTATION” and bearing, the disclosure of which is incorporated herein, in its entirety, by reference. CROSS REFERENCE TO RELATED APPLICATIONS This application is related to U.S. patent application Ser. No. 09/632,662, filed on even date herewith, entitled “SYSTEM AND METHOD FOR PRE-PROCESSING A VIDEO SIGNAL” and, naming Jeff S. Ford and David J. Stradley as inventors, the disclosure of which is incorporated herein, in its entirety, by reference, U.S. patent application Ser. No. 09/632,452, filed on even date herewith, entitled “SYSTEM AND METHOD FOR PRODUCING A VIDEO SIGNAL” and, naming Jeff S. Ford and Claude Denton as inventors, the disclosure of which is incorporated herein, in its entirety, by reference, U.S. patent application Ser. No. 09/632,605, filed on even date herewith, entitled “VIDEO CARD WITH INTERCHANGEABLE CONNECTOR MODULE” and, naming Jeff S. Ford and Jeff Belote as inventors, the disclosure of which is incorporated herein, in its entirety, by reference, U.S. patent application Ser. No. 09/632,443, filed on even date herewith, entitled “SYSTEM AND METHOD FOR FRAME RATE MATCHING” and, naming Jeff S. Ford as inventor, the disclosure of which is incorporated herein, in its entirety, by reference, and U.S. patent application Ser. No. 09/632,451, filed on even date herewith, entitled “SYSTEM AND METHOD FOR PACKING AND UNPACKING VIDEO DATA” and, naming Jeff S. Ford, Arthur McKinney and Craig Jordan as inventors, the disclosure of which is incorporated herein, in its entirety, by reference. FIELD OF THE INVENTION The invention generally relates to a video graphics workstation and, more particularly, the invention relates to the pre-processing of a video signal and the production of a video signal. BACKGROUND OF THE INVENTION In general, a video graphics workstation is a system of hardware and software that allows a user to process a video signal for use in a number of different applications. For example, the user may process a video signal for display on a computer monitor, for storage on a computer-readable storage medium, for display on a television, or for storage on a video tape. Typically, however, video graphics workstations are designed to process particular video signals. Thus, most video graphics workstations are not scalable. In other words, most video graphics workstations are not designed to adapt to the changing needs of the workstation's user. SUMMARY OF THE INVENTION In accordance with one aspect of the invention, a workstation for processing and producing video signals comprises a video input system and a video graphics processor. The video input system comprises a video input module, a first video pipeline, and a second video pipeline. The video input module receives and forwards one or more live video signals, producing a forwarded video signal for each received live video signal. The first video pipeline pre-processes VS 1 , wherein VS 1 is a first stored video signal or one of the forwarded video signals produced in the video input module, producing a first pre-processed video signal. The second video pipeline pre-processes VS 2 , wherein VS 2 is the same video signal being pre-processed in the first video pipeline, one of the other forwarded video signals produced in the video input module or a second stored video signal, producing a second pre-processed video signal. The video graphics processor processes VS 3 , wherein VS 3 is a third stored video signal, the first pre-processed video signal, or the second pre-processed video signal, producing a processed video signal. In a further embodiment of the invention, the workstation may further comprise a video output system, the video output system producing a formatted video signal. The video output system may further comprise a receiver for receiving VS 4 , wherein VS 4 is the first pre-processed video signal, the second pre-processed video signal, or the processed video signal, a video pipeline for post-processing VS 4 , the video pipeline operating in conjunction with the video graphics processor and producing a post-processed video signal, and a video output module for converting the post-processed video signal, the video output module producing the formatted video signal. In accordance with another aspect of the invention, a workstation for processing and producing video signals comprises a video graphics processor for processing a video signal, the video graphics processor producing a processed video signal, and a video output system. The video output system comprises a receiver for receiving the processed video signal, a video pipeline for post-processing the processed video signal, the video pipeline producing a post-processed video signal, and a video output module for converting the post-processed video signal, the video output module producing a formatted video signal. In accordance with still another aspect of the invention, a workstation for processing and producing video signals comprises a video graphics processor for processing a video signal, the video graphics processor producing a processed video signal, and a video output system. The video output system comprises a video processing module for post-processing the processed video signal, the video processing module producing a post-processed video signal and having a connector for coupling a video output module, and a video output module for converting the post-processed video signal, the video output module having a specific configuration and producing a formatted video signal, the specific configuration of the video output module setting the characteristics of the video processing module. In a further embodiment of the invention, the video output module may further comprise a buffer for storing the post-processed video signal, a processor for converting the post-processed video signal into the formatted video signal, and a transmitter for transmitting the formatted video signal. In accordance with yet another aspect of the invention, a workstation for processing and producing a video signal comprises a video input system and a video graphics processor. The video input system comprises a video input module for converting a live video signal, the video input module having a specific configuration and producing a formatted video signal, and a video processing module for pre-processing the formatted video signal, the video processing module producing a pre-processed video signal, the video processing module having a connector for coupling the video input module, the specific configuration of the video input module setting the characteristics of the video processing module. The video graphics processor processes the pre-processed video signal, producing, a processed video signal. In a further embodiment of the invention, the video input module may further comprise a first receiver for receiving the live video signal, a processor for converting the live video signal into the formatted video signal, and a buffer for storing the formatted video signal. In accordance with still yet another aspect of the invention, a workstation for processing and producing a video signal comprises a video input system and a video output system. In one embodiment of the invention, the video input system comprises a video input module for receiving and forwarding one or more live video signals, the video input module producing a forwarded video signal for each received live video signal, a first video pipeline for pre-processing VS 1 , wherein VS 1 is a first stored video signal or one of the forwarded video signals produced in the video input module, the first video pipeline producing a first pre-processed video signal, and a second video pipeline for pre-processing VS 2 , wherein VS 2 is the same video signal being pre-processed in the first video pipeline, one of the other forwarded video signals produced in the video input module, or a second stored video signal, the second video pipeline producing a second pre-processed video signal. In this embodiment, the video-output-system comprises a receiver for receiving VS 3 , wherein VS 3 is a third stored video signal, the first pre-processed video signal, or the second pre-processed video signal, a video pipeline for post-processing VS 3 , the video pipeline producing a post-processed video signal, and a video output module for converting the post-processed video signal, the video output module producing a formatted video signal. In another embodiment of the invention, the video input system comprises a video input module for converting a live video signal, the video input module having a specific configuration and producing a formatted video signal, and a video processing module for pre-processing the formatted video signal, the video processing module producing a pre-processed video signal, the video processing module having a connector for coupling the video input module, the specific configuration of the video input module setting the characteristics of the video processing module. In this embodiment, the video output system comprises a video processing module for post-processing the pre-processed video signal, the video processing module producing a post-processed video signal and having a connector for coupling a video output module, and a video output module for converting the post-processed video signal, the video output module having a specific configuration and producing-a formatted video signal, the specific configuration of the video output module setting the characteristics of the video processing module. In alternate embodiments for all aspects of the invention, the video input system may include an ancillary data extractor for removing ancillary data from at least one of the live video signals, and the video output system may include an ancillary data injector for inserting ancillary data into the post-processed video signal. The video output system may also include a generator locking device. In other alternate embodiments for all aspects of the invention, the live video signal may be an analog composite video signal, an analog component video signal, a serial digital composite video signal, a serial digital component video signal, a parallel digital composite video signal, or a parallel digital component video signal. Further, the pre-processed video signal may be an RGB encoded video signal, an RGBA encoded video signal, a YUV-Type encoded video signal, or a YUVA-Type encoded video signal. In addition, the formatted video signal may be an analog composite video signal, an analog component video signal, a serial digital composite video signal, a serial digital component video signal, a parallel digital composite video signal, or a parallel digital component video signal. In still other, alternate embodiments for all aspects of the invention, the process of pre-processing may include changing the sample rate of the video signal being pre-processed, gamma removal, gamma insertion, color space conversion, dithering, and scaling. In addition, the process of pre-processing may include addressing on a frame-by-frame basis the video signal being pre-processed. Further, the video input system may be a Peripheral Component Interconnect circuit board. In-yet other alternate embodiments for all aspects of the invention, the process of post-processing may include region of interest selection, frame rate matching, scaling, framing, letter boxing, changing the sample rate of the video signal being post-processed, gamma removal, gamma insertion, color space conversion, and changing frames of video data into interleaved fields of video data. In addition, the process of post-processing may include addressing on a frame-by-frame basis the video signal being pre-processed. Further, the video output system may be a Peripheral Component Interconnect circuit board. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects and advantages of the invention will be appreciated more fully from the following further description thereof with reference to the accompanying drawings wherein: FIG. 1 shows a block diagram of an exemplary video graphics workstation for implementing the various embodiments of the invention. FIGS. 2 a through 2 b show various exemplary embodiments for a video input system for use in a video graphics workstation. FIG. 3 shows an exemplary embodiment for a scalable video input system for use in a video graphics workstation. FIGS. 4 a and 4 b show various exemplary exploded views for mounting an interchangeable connector module to a video processing module. FIG. 5 shows an exemplary embodiment for a video output system for use in a video graphics workstation. FIG. 6 shows an exemplary embodiment for a scalable video output system for use in a video graphics workstation. FIG. 7 shows an exemplary video graphics workstation for carrying out various exemplary video graphics applications. FIG. 8 shows an exemplary process in a video graphics workstation for video signal frame rate matching. FIGS. 9 a and 9 b show an exemplary process in a video graphics workstation for packing and unpacking pixels. DETAILED DESCRIPTION OF THE INVENTION In accordance with one embodiment of the invention, a video graphics workstation includes three sub-systems—a video input system, a video graphics processor, and a video output system. In general, the video input system pre-processes video signals, the video graphics processor processes and/or displays video signals and graphics input, and the video output system produces video signals. The video signals processed and produced may be analog video signals or digital video signals. FIG. 1 shows a block diagram of an exemplary video graphics workstation for implementing the various embodiments of the invention. Video graphics workstation 100 includes central processing unit 102 , chipset 104 , memory 106 , two Peripheral Component Interconnect (“PCI”) buses—a 64-bit PCI bus and a 32-bit PCI bus, and an Accelerated Graphics Port (“AGP”). Video input system 110 and storage medium 120 connect to chipset 104 via the 64-bit PCI bus. Video graphics processor 130 connects to chipset 104 via the AGP. Video output system 140 connects to chipset 104 via the 32-bit PCI bus. In addition, video input system 110 connects to video graphics processor 130 via local bus 182 and video output system 140 connects to video graphics processor 130 via local bus 184 . A. Video Input System FIGS. 2 a through 2 b show various exemplary embodiments for video input system 110 . In particular, FIG. 2 a shows an exemplary embodiment for pre-processing a live video signal in video input system 110 . The process of pre-processing a video signal includes, among other things, up sampling, down sampling, gamma insertion, gamma removal, color space conversion, scaling and dithering. For purposes of understanding and reference, and without intending to limit the meaning the above-identified processes have to a person of ordinary skill in the art, listed below are definitions for the above-identified processes: PROCESS DEFINITION Up Sampling Process of increasing the amount of digital data used to represent an image Down Sampling Process of decreasing the amount of digital data used to represent an image Gamma Insertion Process of inserting a value to compensate for the non-linear characteristics of an output device (e.g., a computer monitor) Gamma Removal Process of removing a value inserted to compensate for the non-linear characteristics of an output device (e.g., a computer monitor) Color Space Process of converting between Conversion different color encoding schemes (e.g., between a component color scheme and a composite color scheme) Scaling Process of changing the resolution of an image Dithering Process of combining colors to trick the eye into seeing more colors than the system can actually display In addition, pre-processing may include addressing on a frame-by-frame basis the video signal being pre-processed. In video, a frame is a single complete image. In frame-by-frame addressing, video input system 110 may pre-process one frame of a video signal different than, for example, the next frame of the video signal. In the embodiment shown in FIG. 2 a , video input system 110 includes video input module 200 , input multiplexer 212 , input multiplexer 222 , pipeline 210 , pipeline 220 , output multiplexer 214 , and output multiplexer 224 . Video input module 200 receives a live video signal and forwards the live video signal to, for example, a buffer (not shown) for transfer to pipeline 210 and/or pipeline 220 . The live video signal may be an analog video signal or a digital video signal. If the live video signal is an analog video signal, then video input module 200 converts the live video signal into a computer-readable format. The input multiplexers, multiplexer 212 and multiplexer 222 , route the respective video signal to the pipelines. In particular, multiplexer 212 routes video signals to pipeline 210 and multiplexer 222 routes video signals to pipeline 220 . The pipelines, pipeline 210 and pipeline 220 , pre-process the forwarded video signal. The output multiplexers, multiplexer 214 and multiplexer 224 , route the pre-processed video signals to, for example, various output buffers (not shown) accessible to video graphics workstation 100 . For example, the pre-processed video signal may be forwarded, via the 64-bit PCI bus and the AGP, to video graphics processor 130 . Or, the pre-processed video signal may be forwarded, via the 64-bit PCI bus and the 32-bit PCI bus, to video output system 140 . The pre-processed video signal may also be forwarded, via the 64-bit bus, to storage medium 120 . FIG. 2 b shows an exemplary embodiment for pre-processing a live video signal and a stored video signal in video input system 110 . In this embodiment, pipeline 210 and pipeline 220 pre-process a live video signal and/or a stored video signal. Typically, the stored video signal is forwarded from, for example, storage medium 120 , to a buffer (not shown) to allow for efficient transfer of the stored video signal to video input system 110 . With two pipelines, a single live, or stored, video signal may reach pipeline 210 and pipeline 220 . Thus, two versions of a single live, or stored, video signal may be generated at the same time. For example, video input system 110 may receive a television signal and pre-process the televison signal via pipeline 210 for display on a computer monitor and via pipeline 220 for storage on storage medium 120 . In addition, using frame-by-frame addressing, video input system 110 may pre-process more than two video signals substantially at the same time. In this embodiment, the frames of the different video signals are interleaved and routed to pipeline 210 and pipeline 220 . Moreover, video input system 110 may pass a video signal, either live or stored, through pipeline 210 and/or pipeline 220 without pre-processing the video signal. In a further embodiment of video input system 110 , video input module 200 receives and forwards more than one live video signal to, for example, a buffer (not shown) for transfer to pipeline 210 and/or pipeline 220 . The live video signals may be analog video signals or digital video signals. If the live video signal is an analog video signal, then video input module 200 converts the live video signal into a computer-readable format. For each received live video signal, video input module 200 produces a forwarded video signal. In a further embodiment of these exemplary embodiments, video input module 200 includes an ancillary data extractor for removing ancillary data from a live video signal. Typically, the ancillary data is removed from the live video signal prior to receipt of the live video signal in the input multiplexers, multiplexer 212 and multiplexer 214 . Ancillary data includes, among other things, audio data and close captioning data. FIG. 3 shows an exemplary embodiment for a scalable video input system 110 . In this embodiment, video input system 110 includes video input module 300 and video processing module 350 . Video input module 300 includes receiver 302 , processor 304 , and buffer 306 . Receiver 302 receives a live video signal and forwards the live video signal to processor 304 . Processor 304 converts the received video signal into a video signal having a common video data format. The formatted video signal is then forwarded to buffer 306 for transfer to video processing module 350 . In alternate embodiments of the invention, video input module 300 may include an ancillary data extractor for removing ancillary data from a live video signal. Video processing module 350 includes input multiplexer 352 , pipeline 354 , and output multiplexer 356 . As discussed above in regard to the embodiments shown in FIG. 2 , video processing module 350 pre-processes the formatted video signal and/or a stored video signal and routes the pre-processed video signal to, for example, a buffer (not shown) accessible to video graphics workstation 100 . Video processing module 350 may have two pre-processing pipelines. In addition, the pre-processed video signal may be forwarded to video graphics processor 130 , video output system 140 , and/or storage medium 120 . The common video data format may be an organized bit stream. As noted above, a frame is a single complete image. An image, in turn, is composed of a raster of picture elements, referred to as pixels. A pixel is represented by some number of bits stored, for example, in memory. Pixels are the smallest “units” on a screen that can be given a color (represented with color data) and an opacity (represented with alpha data). Thus, an organized bit stream may include color data, alpha data, or color data and alpha data. For example, a bit stream with color data may include 20-bits for color data. In contrast, a bit stream for alpha data may include 10-bits for alpha data. Pipeline 354 may pre-process color data separate from alpha data. In this embodiment, a color data bit stream may be forwarded on a output different from the output used to forward alpha data. In these exemplary embodiments, video input module 300 and video processing module 350 are separate modules coupled together via, for example, male/female cables. In one embodiment, video input module 300 is a daughterboard that plugs into video processing module 350 . The separation of the various functions of a video input system into a video input module and a video processing module allows for the separation of video input module 300 and video processing module 350 . In turn, the separation of video input module 300 from video processing module 350 allows for the configuration of various video input modules, each configured to receive and process different video signal formats. Because the “input” functions of video input system 110 have been separated from the “processing” functions of video input system 110 , video input module 300 may be “exchanged” without the need to replace video processing module 350 . Thus, when a user wants to input, for example, a serial digital component video signal into video input system 110 instead of an analog composite video signal, the user “exchanges” the video input module configured for the analog composite video signal with a video input module configured for the serial digital component video signal. In turn, processor 304 (on the “new” video input module) signals video processing module 350 of the new configuration. FIGS. 4 a and 4 b show various exemplary exploded views for mounting an interchangeable connector module, such as video input module 300 , to a processing module, such as video processing module 350 . In FIG. 4 a , interchangeable connector module 400 includes connectors 402 and mounting holes 404 . Circuit board 450 includes plate 455 . Plate 455 includes connector holes 452 and mounting holes 454 . Plate assembly 430 includes plate 435 a and two screws (not shown). Plate 435 a includes connector holes 432 a and mounting holes 434 a . Connectors 402 are designed to fit through connector holes 432 and 452 . The two screws, passing through mounting holes 434 a and mounting holes 454 , secure interchangeable connector module 400 to circuit board 450 via mounting holes 404 . In FIG. 4 b , plate assembly 430 further includes plate 435 b and gaskets 436 . Gaskets 436 are designed to improve electromagnetic shielding. For example, gaskets 436 may be composed of a rubber compound with embedded silver. For the exemplary embodiments shown in both FIG. 4 a and FIG. 4 b , in operation, interchangeable connector module 400 would also be coupled (not shown) to processing module 450 . B. Video Graphics Processor Various exemplary embodiments of a video graphics processor are disclosed in the following: 1. U.S. patent application Ser. No. 09/353,495, filed Jul. 15, 1999, and entitled “MULTIPROCESSOR GRAPHICS ACCELERATOR,” the disclosure of which is hereby incorporated, in its entirety, by reference; 2. U.S. patent application Ser. No. 09/354,462, filed Jul. 15, 1999, and entitled “APPARATUS AND METHOD OF DIRECTING GRAPHICAL DATA TO A DISPLAY DEVICE,” the disclosure of which is hereby incorporated, in its entirety, by reference; 3. U.S. patent application Ser. No. 09/353,420, filed Jul. 15, 1999, and entitled “WIDE INSTRUCTION WORD GRAPHICS PROCESSOR,” the disclosure of which is hereby incorporated, in its entirety, by reference; and 4. U.S. patent application Ser. No. 09/353,419, filed Jul. 15, 1999, and entitled “SYSTEM FOR DISPLAYING A TELEVISION SIGNAL ON A COMPUTER MONITOR,” the disclosure of which is hereby incorporated, in its entirety, by reference. C. Video Output System FIG. 5 shows an exemplary embodiment for video output system 140 . In FIG. 5 , video output system 140 includes receiver 500 , pipeline 510 , and video output module 520 . Receiver 500 receives a video signal and forwards the received video signal to, for example, a buffer (not shown) for transfer to pipeline 510 . The received video signal may be formatted in one of many different video data formats. For example, the received video signal may be an RGB encoded video signal or an RGBA encoded video signal. An RGB encoded video signal encodes an image in accordance with the amount of red, green, or blue contained in the image. An RGBA encoded video signal further encodes an image in accordance with the amount of opacity contained in the image. The received video signal may also be a “YUV-Type” encoded video signal or a “YUVA-Type” encoded video signal. A “YUV-Type” encoded video signal encodes an image in accordance with the amount of luma (black and white) and color differences contained in the image. A “YUVA-Type” encoded video signal further encodes an image in accordance with the amount of opacity contained in the image. A “YUV-Type” encoded video signal includes, among other things, a YUV encoded video signal, a YCbCr encoded video signal, and a YPbPr encoded video signal. A “YUVA-Type” encoded video signal includes, among other things, a YUVA encoded video signal, a YCbCrA encoded video signal, and a YPbPrA encoded video signal. Pipeline 510 post-processes the forwarded video signal and forwards the post-processed video signal to video output module 520 . The process of post-processing includes, among other things, region of interest selection, frame rate matching, spatial adaptation, up sampling, down sampling, gamma insertion, gamma removal, and color space conversion. Spatial adaptation includes, among other things, scaling and picture framing. Picture framing includes, among other things, letter boxing. For purposes of understanding and reference, and without intending to limit the meaning the above-identified processes have to a person of ordinary skill in the art, listed below are definitions for the above-identified processes not previously defined: PROCESS DEFINITION Region of Interest Process of selecting a portion of an Selection image for post-processing Frame Rate See Section E. Matching Picture Framing Process of positioning an image on a and Letter Boxing background image In addition, post-processing may include addressing on a frame-by-frame basis the video signal being post-processed. In frame-by-frame addressing, video output system 140 may post-process one frame of a video signal different than, for example, the next frame of the video signal. Also, post-processing may include changing a frame of video data into interlaced fields of video data. In using this process, video output system 140 “blends” single or multiple lines from a frame in an input video signal into a single line in an output video signal, e.g, 3:2 pull-down. Video output module 520 converts the post-processed video signal to a formatted video signal. The formatted video signal may be an analog video signal or a digital video signal. Typically, video output system 140 also includes a generator locking device, referred to as a genlock, which allows the synchronized display of graphics and video. A genlock may lock video output system 140 to, for example, video graphics processor 130 . In addition, regardless of whether video output system 140 is locked to video graphics processor 130 , a genlock may lock video output module 520 to another source, e.g., an external clock, an internal clock, etc. In a further embodiment of these exemplary embodiments, video output module 520 includes an ancillary data injector for inserting ancillary data into the post-processed video signal prior to conversion of the post-processed video signal. As noted above, ancillary data includes, among other things, audio data and close captioning data. FIG. 6 shows an exemplary embodiment for a scalable video output system 140 . In this embodiment, video output system 140 includes video processing module 600 and video output module 650 . Video processing module 600 includes receiver 602 and pipeline 604 . As discussed above in regard to the embodiments shown in FIG. 3 , video processing module 600 receives a video signal, post-processes the received video signal, and forwards the post-processed video signal to video output module 650 . Video processing module 600 may include a generator locking device for locking video processing module 600 to, for example, video graphics processor 130 . Video output module 650 includes buffer 652 , processor 654 , and transmitter 656 . Video processing module 600 forwards the post-processed video signal to buffer 652 for transfer to processor 654 . Processor 654 converts the post-processed video signal into a formatted video signal, e.g., an analog composite video signal, a parallel digital component video signal, etc. The formatted video signal is then forwarded to transmitter 656 . In alternate embodiments of the invention, video output module 650 may include an ancillary data injector for inserting ancillary data into the post-processed video signal. In these exemplary embodiments, video output module 650 and video processing module 600 are separate modules coupled together via, for example, male/female cables. In one embodiment, video output module 650 is a daughterboard that plugs into video processing module 600 . The separation of the various functions of a video output system into a video output module and a video processing module allows for the separation of video output module 650 and video processing module 600 . In turn, the separation of video output module 650 from video processing module 600 allows for the configuration of various video output modules, each configured to process and produce different video signal formats. Because the “output” functions of video output system 140 have been separated from the “processing” functions of video output system 140 , video output module 650 may be “exchanged” without the need to replace video processing module 600 . Thus, when a user wants to output, for example, a serial digital component video signal instead of an analog composite video signal, the user “exchanges” the video output module configured for the analog composite video signal with a video output module configured for the serial digital component video signal. In turn, processor 654 (on the “new” video output module) signals video processing module 600 of the new configuration. As an interchangeable connector module, video output module 650 may be mounted on video processing module 600 , a processing module, in the manner shown in FIGS. 4 a and 4 b. D. Exemplary Video Graphics Applications FIG. 7 shows an exemplary video graphics workstation implementing one embodiment of the invention for carrying out various exemplary video graphics applications In this embodiment, video input system 730 includes two pipelines, pipeline 732 and pipeline 734 . In addition, video output system 750 forwards a formatted video signal to a video tape recorder for recordation. In one application, video graphics workstation 700 captures a live video signal. First, video graphics workstation 700 receives the live video signal. Next, the received video signal is pre-processed in pipeline 732 of video input system 730 . Then, the pre-processed video signal is forwarded, via the 64-bit PCI bus, to storage medium 720 . In another application, video graphics workstation 700 captures and displays a live video signal. First, video graphics workstation 700 receives the live video signal. Next, the received video signal is pre-processed in both pipeline 732 and pipeline 734 of video input system 730 . Then, the pre-processed video signal from pipeline 732 is forwarded, via the 64-bit PCI bus, to storage medium 720 . In the interim, the pre-processed video signal from pipeline 734 is forwarded, via local bus 782 , to video graphics processor 740 for display on computer monitor 760 . The pre-processed video signal from pipeline 734 may also be forwarded to video graphic processor 740 via the 64-bit PCI bus and the AGP. In alternate embodiments, the pre-processed video signal from pipeline 734 may be forwarded, via the 64-bit bus and the 32-bit bus, to video output system 750 for recordation on video tape recorder 770 . In another application, video graphics workstation 700 plays back a stored video signal. First, video graphics workstation 700 forwards a stored video signal, via the 64-bit PCI bus to video input system 730 . Next, the stored video signal is pre-processed in pipeline 732 . Then, the pre-processed video signal is forwarded, via local bus 782 , to video graphics processor 740 for display on computer monitor 760 . In an alternate embodiment, the pre-processed video signal may also be forwarded, via local bus 784 , to video output system 750 for recordation on video tape recorder 770 . In another application, video graphics workstation 700 processes a stored video signal, for example, performs a two-dimensional or three-dimensional effect on the stored video signal, and displays the processed video signal. First, video graphics workstation 700 forwards a stored video signal, via the 64-bit PCI bus, to video input system 730 . Next, the stored video signal is pre-processed in pipeline 732 . Then, the pre-processed video signal is forwarded, via local bus 782 , to video graphics processor 740 for “effects” processing and display on a computer monitor 760 . In an alternate embodiment, the processed video signal may also be forwarded, via local bus 784 , to video output system 750 for recordation on video tape recorder 770 . In another application, video graphics workstation 700 pre-processes a stored video signal and saves the pre-processed video signal. First, video graphics workstation 700 forwards a stored video signal, via the 64-bit PCI bus, to video input system 730 . Next, the stored video signal is pre-processed in pipeline 732 . Then, the pre-processed video signal is forwarded, via the 64-bit PCI bus, to storage medium 720 . In alternate embodiments, the pre-processed video signal may be forwarded, via the 64-bit PCI bus, to central processing unit 715 or to memory 710 . In another application, video graphics workstation 700 processes a stored video signal and saves the processed video signal. First, video graphics workstation 700 forwards a stored video signal, via the 64-bit PCI bus, to video input system 730 . Next, the stored video signal is pre-processed in pipeline 732 . Then, the pre-processed video signal is forwarded, via local bus 782 , to video graphics processor 740 for “effects” processing. Last, the processed video signal is forwarded, via local bus 782 , to video input system 730 . Video input system 730 may pre-process the processed video signal, for example, to convert the processed signal to a format better suited for saving, or forward the processed signal, via the 64-bit PCI bus, to storage medium 720 . In another application, video graphics workstation 700 combines a live video signal, a stored video signal, and graphics information and records the combined video signal. First, video graphics workstation 700 receives a live video signal. Next, the received video signal is pre-processed in pipeline 732 of video input system 730 . In the interim, video graphics workstation 700 forwards a stored video signal to video input system 730 . Next, the stored video signal is pre-processed in pipeline 734 . Then, graphics information (via the AGP), the pre-processed video signal from pipeline 732 (via local bus 782 ), and the pre-processed video signal from pipeline 734 (via local bus 782 ) are forwarded to video graphics processor 740 for “effects” processing. Last, the processed video signal is forwarded, via local bus 784 , to video output system 750 for recordation on video tape recorder 770 . E. Frame Rate Matching As discussed above, a frame is a single complete image. Typically, a frame is represented, in a video graphics workstation, with frame data. In general, frame rate is how fast a new frame of frame data, in other words, an new image, is available for processing or display. The process of frame rate matching includes, among other things, matching the frame rate of, for example, a video signal to the frame rate of, for example, an output device. Typically, in a video graphics workstation, the process of frame rate matching occurs in the video output system. FIG. 8 shows an exemplary process in a video graphics workstation for video signal frame rate matching. The process begins at step 800 , in which the video graphics workstation fills a first buffer with a sequence of frame data. Next, at step 810 , the workstation reads out the frame data in the first buffer and, at substantially the same time, fills a second buffer with the next sequence of frame data. The process continues at step 820 , in which the video graphics workstation determines whether all of the frame data has been read out of the first buffer. If yes, the video graphics workstation fills the first buffer with the next sequence of frame data. If no, the video graphics workstation, at step 830 , fills the third buffer with the next sequence of frame data. Next, at step 840 , the video graphics workstation determines whether all of the frame data in the first buffer has been read out of the first buffer. If no, the video graphics workstation begins to fill the second buffer with the next sequence of frame data. If yes, the video graphics workstation, at step 850 , determines whether the second buffer or the third buffer has the most current and most complete frame data. If the second buffer has the most current and most complete frame data, the video graphics workstation, at step 860 , reads the frame data out of the second buffer. If the third buffer has the most current and most complete frame data, the video graphics workstation, at step 870 , reads the frame data out of the third buffer. In a further embodiment of the invention, the buffer determined not to have been filled with the most current and most complete frame data becomes a remainder buffer. In this embodiment, the video graphics workstation fills the remainder buffer with the next sequence of frame data. Then, if all of the frame data has not been read out of the buffer determined to have been filled with the most current and most complete frame data, the video graphics workstation fills the first buffer with the next sequence of frame data. The video graphics workstation continues to alternate between the remainder buffer and the first buffer until all of the frame data has been read out of the buffer determined to have been filled with the most current and most complete frame data. Thus, in operation, the three buffers change “roles.” For example, the buffer now being filled may, depending upon the circumstances, next become either the buffer being read or the buffer not being either filled or read. Or, the buffer now being read may, depending upon the circumstances, next become either the buffer being filled or the buffer not being either filled or read. Or, the buffer now not being either filled or read may, depending upon the circumstances, next become either the buffer being read or the buffer being filled. In both embodiments of the invention, a buffer may contain the most complete frame data when the buffer is less than 100% full. Typically, however, a buffer contains the most complete frame data when the buffer is 100% full. In addition, a buffer may contain one or more frames of frame data. Typically, however, a buffer contains one frame of frame data. Further, both embodiments of the invention are scalable. In other words, both embodiments of the invention may be used to match any frame rates. For example, a frame rate to be matched may be 24/1.001 frames/second, or 24 frames/second, or 25 frames/second, or 29.97 frames/second, or 30/1.001 frames/second, or 30 frames/second, or 50 frames/second, 60/1.001 frames/second, 60 frames/second or 75 frames/second. Also, the frame rates being matched may be the same frame rate. Or, in the alternative, the frame rates being matched may be multiples of each other. F. Packing and Unpacking Video Data As discussed above, an image is composed of a raster of picture elements, referred to as pixels. Pixels are the smallest “units” on a screen that can be given a color (represented with color data) and an opacity (represented with alpha data). In general, a pixel is represented by some number of bits stored, for example, in memory. For example, a pixel may be 1-bit in length, 8-bits in length, 10-bits in length, 24-bits in length, or 32-bits in length. In turn, memory stores data in segments, with each segment being some number of bits. For example, memory may be capable of storing data in 32-bit segments or 64-bit segments. It may inefficient, however, to store, for example, one 8-bit pixel in a 32-bit memory segment. But, four 8-bit pixels may be “packed” in a 32-bit memory segment. In the same way, four 24-bits pixels may be packed in three 32-bit memory segments. Typically, in a video graphics workstation, the process of packing and unpacking pixels occurs in the video input system. FIGS. 9 a and 9 b show an exemplary process in a video graphics workstation for packing and unpacking pixels. In particular, FIG. 9 a shows an exemplary process in a video graphics workstation for unpacking pixels. The process begins at step 900 a , in which the video graphics workstation loads a shift-down register with the pixel data contained in a first memory device. In this embodiment, the first memory device has a bit storage capacity smaller in size than the bit storage capacity of the shift-down register. For example, the first memory device may be 64-bits in length and the shift-down register may be 80-bits in length. Next, at step 910 a , the video graphics workstation shifts one complete pixel of pixel data down the shift-down register. For example, one 24-bit pixel is shifted down the shift-down register. Then, at step 920 a , the video graphics workstation determines whether the shift-down register contains another complete pixel of pixel data. If yes, the video graphics workstation shifts another complete pixel of pixel data down the shift-down register. If no, the video graphics workstation, at step 930 a , loads a shift-up register with the pixel data contained in a second memory device. In this embodiment, the second memory device is contiguous with the first memory device and has the same bit storage capacity as the first memory device. Also, the shift-up register has the same bit storage capacity as the shift-down register. Next, at step 940 a , the video graphics workstation shifts the pixel data in the shift-up register up the number of bits of pixel data remaining in the shift-down register. For example, if the shift down register has 16 bits of pixel data remaining, then the video graphics workstation shifts the pixel data in the shift-up register up 16 bits. Then, at step 950 a , the video graphics workstation moves the pixel data in the shift-up register to the shift-down register, placing the shifted-up pixel data in the same bit locations in the shift-down register the shifted-up pixel data occupied in the shift-up register. For example, if the shifted-up pixel data occupied bit locations 16 through 63 in the shift-up register, then the video graphics workstation moves the shifted-up pixel data to bit locations 16 through 63 in the shift-down register. FIG. 9 b shows an exemplary process in a video graphics workstation for packing pixels. In this embodiment, the memory device in which the pixel data will be packed has a bit storage capacity smaller in size than the bit storage capacity of the shift-up register. For example, the memory device may be 64-bits in length and the shift-up register may be 80-bits in length. The process begins at step 900 b , in which the video graphics workstation shifts one complete pixel of data up a shift-up register. Next, at step 910 b , the vide graphics workstation determines whether the shift-up register has capacity to hold another complete pixel of pixel data. If yes, the video graphics workstation shifts another complete pixel of pixel data up the shift-up register. If no, the video graphics workstation, at step 920 b , moves the pixel data in the uppermost bit locations of the shift-up register to a shift-down register, placing the moved pixel data in the same bit locations in the shift-down register the moved pixel data occupied in the shift-up register. For example, if the moved pixel data occupied bit locations 16 through 63 in the shift-up register, then the video graphics workstation moves the shifted-up pixel data to bit locations 16 through 63 in the shift-down register. The amount of pixel data moved from the uppermost bit locations in the shift-up register depends upon the bit storage capacity of the memory device in which the pixel data will be packed. For example, if the memory device is 64-bits in length, then the video graphics workstation moves the 64 uppermost bits of the shift-up register to the shift-down register. Also, the shift-down register has the same bit storage capacity as the shift-up register. Next, at step 930 b , the video graphics workstation shifts the pixel data in the shift-down register down the number of bits of pixel data remaining in the shift-up register. For examples, if the shift-up register has 16 bits of pixel data remaining, then the video graphics workstation shifts the pixel data in the shift-down register down 16 bits. Then, at step 940 b , the video graphics workstation moves the contents of the shift-down register to the memory device. In all embodiments of the invention, one complete pixel of pixel data may include a bit stream of color data, a bit stream of alpha data, or a bit stream of color data and alpha data. The color data may be RGB encoded or “YUV-Type” encoded. In addition, the color data and alpha data may be RGBA encoded or “YUVA-Type” encoded. The various embodiments of the invention may be implemented in any conventional computer programming language. For example, the various embodiments may be implemented in a procedural programming language (for example, “C”) or an object-oriented programming language (for example, “C++” or JAVA). The various embodiments of the invention may also be implemented as preprogrammed hardware elements (for example, application specific integrated circuits or digital processors), or other related components. The various embodiments of the invention may be also implemented as a computer program product for use with a computer system. Such implementation may include a series of computer instructions fixed either on a tangible medium, such as a computer readable media (for example, a diskette, CD-ROM, ROM, or fixed disk), or transmittable to a computer system via a modem or other interface device, such as a communications adapter connected to a network over a medium. The medium may be either a tangible medium (for example, optical or analog communications lines) or a medium implemented with wireless techniques (for example, microwave, infrared or other transmission techniques). The series of computer instructions preferably embodies all or part of the functionality previously described herein with respect to the system. Those skilled in the art should appreciate that such computer instructions can be written in a number of programming languages for use with many computer architectures or operating systems. Furthermore, such instructions may be stored in any memory device, such as semiconductor, magnetic, optical or other memory devices, and may be transmitted using any communications technology, such as optical, infrared, microwave, or other transmission technologies. It is expected that such a computer program product may be distributed as a removable medium with accompanying printed or electronic documentation (for example, shrink wrapped software), pre-loaded with a computer system (for example, on system ROM or fixed disk), or distributed from a server or electronic bulletin board over the network (for example, the Internet or World Wide Web). Although various exemplary embodiments of the invention have been disclosed, it should be apparent to those skilled in the art that various changes and modifications can be made which will achieve some of the advantages of the invention without departing from the true scope of the invention. These and other obvious modifications are intended to be covered by the appended claims.

A workstation for processing and producing a video signal comprises a video input system, a video graphics processor, and a video output system. The video input system may comprise a video input module, a first video pipeline, and a second video pipeline. The video output system may comprise a receiver, a video pipeline and a video output module. In addition, the video input system may comprise a video input module having a specific configuration and a video processing module having a connector for coupling the video input module, the specific configuration of the video input module setting the characteristics of the video processing module. The video output system may comprise a video processing module having a connector for coupling a video output module and a video output module having a specific configuration, the specific configuration of the video output module setting the characteristics of the video processing module.

FIELD OF THE INVENTION [0001] The present invention is directed to systems and methods for performing automated auctions, and specifically those auctions involving bidding on items that are somewhat mutually exclusive, and/or those types of auctions which are resolved on a collective basis with reference to more than one demand constraint provided in a bid. BACKGROUND OF THE INVENTION [0002] The practice of online auctions has grown at a dramatic pace. Auction sites have been developed for a wide range of products. This has resulted in an active, dynamic pricing environment for many products. The standard auction practice may result in the maximization of the seller's revenue in some instances. Additional information on electronic auction and bidding systems can be found in such U.S. patents as U.S. Pat. Nos. 6,041,308, 6,021,398, 6,012,046, 6,012,045, 5,924,082, 5,835,896, 5,845,266 and 5,689,652, which are hereby incorporated by reference herein. Commercial examples of auctions systems are also accessible online on the Internet, at websites managed by such companies as E-Bay, Yahoo, and other similar sites. [0003] However, the standard auction practice is limited in some respects. A user may not be able to utilize two mutually exclusive items. For example, one person cannot physically use two golf tee times at the same time, on the same date at two different golf courses. Or, a user may not want to take possession of more than one out of a collection of items. For example, a user may only wish to accept one golf tee time on either Saturday or Sunday, but not a time on both Saturday and Sunday. Therefore, users can bid on only one mutually exclusive item at a time. If they are the high bidder on more than one item, they may dispose of the other item through resale or allowing it to expire in the case of time-based items. At the same time, a user bidding on only one mutually exclusive item decreases the probability they will be successful. If they bid on more than one item, they increase the probability they will be successful bidding on any one of the items. However, they risk being the winning bidder on more than one item. [0004] From the seller's perspective, if bidders only place bids on one mutually exclusive item at a time, the number of bids on any one item will be less than if they placed bids on multiple items simultaneously which lowers the expected winning bid. Also, if bidders limit themselves to a single bid, the probability no one will place a bid on any individual item increases, thus lowering the probability the seller will successfully sell their item. [0005] Furthermore, the standard auction method does not allow the simultaneous maximization of two constraints. For example, a bidder may have a range of preferences and maximum prices they are willing to pay for a set of items. However, standard auction practices do not allow the simultaneous maximization of both user preference and bid prices. They only maximize based upon bid price. While U.S. Pat. No. 5,924,082 referenced above includes an option for providing ranking information, this option does not allow a bidder to prioritize bids in such system. Moreover, the system described therein does not actually consummate a bid for an item, but rather merely identifies potential acceptable transactions between two parties. [0006] Finally, while there is some prior art capability to perform bidding on multiple items of the same kind (in so-called Dutch auctions), the bidding process there is not optimized from the perspective of the seller, since the lowest winning bid price for the item is awarded to all the other winning bids, even if such latter bids are much higher. In other words, if 100 persons bid on 5 identical widgets, the five winning bidders all pay the same price, equal to the 5 th highest bid, and this result can distort the bidding process. SUMMARY OF THE INVENTION [0007] An object of the present invention, therefore, is to eliminate the problems generally inherent in the aforementioned prior art systems. [0008] Another object of the invention is to provide a system and method for flexibly auctioning mutually exclusive items. [0009] It is another object of the invention to allow users to enter bids and a rank order for mutually exclusive items to maximize the users' preference while simultaneously maximizing the bid amount, thus utilizing more than one constraint when conducting an electronic auction. [0010] A further object of the invention is to provide a system and method for allowing a user to enter bids on multiple, mutually exclusive items but only receive the item corresponding to their highest ranked, winning bid. [0011] Yet another object of the invention is to provide a system and method for allowing a seller of a particular item to maximize both the number and quality of bids made in an auction for such item by increasing the probability that an item will receive a bid; [0012] Still another object of the present invention is to provide a mechanism by which a number of similarly related items can be aggregated and auctioned simultaneously to a number of separate purchasers, such as for example, a group of tee times at a particular golf course that are allocated on a daily basis to a group of competing golf players (or alternatively, a group of travel seats, a group of restaurant seats, concert seats, hotel rooms, automobiles, etc.); [0013] A related object of the present invention is to further organize and combine successful bidders at the end of the auction so that their enjoyment of the item is further optimized, such as, for example, in the case of a group of persons successfully bidding for a golf tee time, where such persons can be allocated a priority of play within such tee time that ensures maximum playability according to some additional characteristic, such as their skill level; [0014] Still another object of the present invention is to allow a user to minimize their required involvement in the auction process by enabling them to enter multiple bids on multiple items without worry that they will receive more than one item. This can be true when all items are included in an auction ending at the same time or when items are in a series of auctions that close on successive dates. [0015] Still further objects and advantages will become apparent from a consideration of the ensuing description and accompanying drawings. These advantages and many more are realized by the many aspects and features of the present inventions, which include: [0016] A first aspect of the present invention, including a system and method for allowing a bidder to enter bid information for an electronic auction, which incorporates the steps of: reviewing a database of items available for auction; entering a set of bids for a corresponding set of items selected from the database, each bid in the set of bids including at least a bid price and a bid ranking for an item. In this manner, the bidder can specify a bid ranking for an item represents a desired order in which a bid is to be resolved in the electronic auction. [0017] In a variation of this aspect of the invention, a set of bids from any particular bidder each includes a unique bid ranking for each of the corresponding set of items. Furthermore, the bidder can also provide a maximum bid price for each bid, and an auto-bid indicator for raising the bid price as needed until the maximum bid price is reached. The bidder can also monitor a status of the electronic auction, including a high bid for an item, and information relating to other conditional bids for the item, such as a number of conditional bids that equal or exceed the highest unconditional bid. This information helps to stimulate the bidding process, and to enhance the number of bids made by participants. [0018] A further variation of this embodiment presents an option to the bidder so that they can opt out of the auction process if desired by selecting a guaranteed purchase option for an item, which is typically higher than a highest bid price, but avoids further delay and involvement for the bidder. [0019] Another aspect of the present invention concerns a system and method for monitoring bid information for an electronic auction. This includes the following operations: retrieving a set of items from an auction database in accordance with a specified search criteria; displaying the set of items; and for each item in the set of items, displaying a current highest unconditional bid price and information relating to any conditional bids for the item. Again, the display of conditional bid information acts as a facilitator for motivating submission of additional bids by potential purchasers. [0020] In a variation of this aspect of the invention, the set of items displayed correspond to inventory to be auctioned during a common auction period. Furthermore, the information relating to the conditional bids includes a numerical value indicating a number of the conditional bids having a bid price equal to or exceeding the highest unconditional bid price and/or a minimum bid price for the item. [0021] Again in a more specific variant of this aspect of the invention, the auction items correspond to access rights to an entertainment facility, such as a golf course, where the bidders are bidding to perform an activity (such as playing golf at a desired golf tee time such course. Other access rights are also auctionable, of course, for enjoying activities at movie, concert, restaurants, theme parks, travel and other venues to name a few. [0022] Another aspect of the present invention relates to a system and method of participating in an electronic auction which is based on at least two constraints, namely a bid price and a bid rank. This generally comprises the following steps by the bidding participants: reviewing a database of items available for auction; entering a set of bids for a corresponding set of items selected from the database, each bid in the set of bids including at least a bid price and a bid ranking for an item; and processing the set of bids based on both the bid price and the bid ranking for the corresponding set of items to determine if there is at least one winning bid for one of the corresponding set of items. [0023] Again, in a variation on this aspect of the present invention, the auction items are aggregated and considered en masse for a particular auction based on a common predefined auction period. The processing step determines how the corresponding set of items should be auctioned based on first considering a highest ranking bid submitted. During the bid submission process, each user submits a set of bids that includes at least one unconditional bid for a highest ranked item taken from the corresponding set of items, and the remainder of the set of bids are comprised of conditional bids for items ranked below the highest ranked item. The conditional bids are not considered unless the bidder's unconditional bid is unsuccessful for the highest ranked item. [0024] Further in a variant of this aspect of the invention, an additional notification step is performed to notify a bidder when a highest ranked bid is unsuccessful for a corresponding item. This allows the bidder to increase a bid price for the highest ranked bid and thus re-enter the auction process if desired. If the bidder does not change his/her bid, the highest ranked bid is declared inactive, and the next highest bid is now considered. If however, one bid from the set of bids is satisfied for a bidder, any remaining bids are not evaluated for the bidder. In this way, the bidder can be guaranteed never to have to take possession of more than one item, even across multiple item biddings, and multiple auctions. The system also accommodates multiple sets of bids entered by multiple participants in the auction. The multiple sets of bids are subjected to the auction processing to determine a single winning bid for each of the corresponding set of items. [0025] Yet another aspect of the present invention covers a system and method for participating in an electronic auction that considers both conditional and unconditional bids. This system and method uses the following operational steps: selecting a set of N items from a database of items available for auction, the set of N items being characterized by a common auction expiration period; entering a set of N bids for the set of N items, such that the set of N bids includes at least one unconditional bid for one item in the set of N items, and the remainder of the set of N bids being comprised of conditional bids for a remainder of the N items; processing the set of bids prior to the common auction expiration period to determine if there is at least one winning bid in the set of bids, the processing being performed such that the conditional bids are not considered unless the unconditional bid for the one item is unsuccessful, and such that at most only a single item from the set of N items is matched to a single one of the set of N bids when determining the at least one winning bid. [0026] Using this approach, a bidder can control the bidding process by ranking the N bids in accordance with a desired auction resolution order. The items are auctioned based on first considering a highest ranking bid submitted by the bidders, rather than by solely considering a highest bid made for the item. Thus, each set of bids for a bidder includes at least one unconditional bid for a highest ranked item taken from the corresponding set of items, and the remainder of the set of bids are comprised of conditional bids for items ranked below the highest ranked item. [0027] Still a further aspect of the invention includes a system and method that allow a bidder to submit a single set of bids that are considered for more than one auction. This is done generally by a system that can handle the following operations: accepting a first bid for a first auction item that is to be auctioned during a first auction expiration period; and accepting a second bid, prior to expiration of the first auction expiration period, for a second auction item that is to be to be auctioned during a second auction expiration period; processing the first bid prior to the first auction expiration period to determine if it is a winning bid for the first auction item, such that the second bid is discarded when the first bid is a winning bid; and when the first bid is not a winning bid, the second bid is processed prior to the second auction expiration period to determine if it is a winning bid for second auction item. [0028] Thus, the first bid is treated an unconditional bid, and the second bid is treated as a conditional bid until the first bid is determined to be unsuccessful. This way, the bidder can enter even two bids, but at most only one of the first bid and second bid are declared as a winning bid. [0029] A related aspect of the present invention allows a purchaser to more specifically bid on a right of access to one or more facilities, each of which facilities has a finite capacity for accommodating purchasers at a particular time. This aspect of the invention includes a system and method that achieve the following: retrieving access items related to the one or more facilities, the access items each corresponding to an access time available at the one or more facilities; selecting a set of access items from the access items, the set of access items being based on a selected access time and selected facility chosen by the purchaser; entering a set of bids for the set of access items, such that each bid from the set of bids includes both a bid price and a bid ranking for an access item. In this fashion, the purchaser can control through the bid ranking in what order the set of bids are considered to determine whether they are winning bids for any of the access items. [0030] By allowing the set of bids to further include personal information concerning the purchaser (such as the purchaser's skill level at a particular task), such personal information can be compared against that of other purchasers to determine a final access time awarded to the purchaser for the access items. For example, it may be used to ensure that advanced players at a golf course are paired together at an earlier start time than more novice players, to enhance playability and enjoyment for all the participants. [0031] In another variation of this aspect of the invention, a facility manager can participate and manage an auction inventory by dividing a capacity of the facility into a set of access time windows. This allows the capacity to be logically parceled by creating a set of access right items based on the set of access time windows, the access right items including at least an access starting time and access duration associated with performing an activity at the facility. The access right items further include a capacity value specifying a number of persons that can perform the activity at the facility during the access time window. An access time spacing can also be specified such that a plurality of access right items can be associated with an access time window, and the plurality of access right items are separated in time by the access time spacing. For instance, a particular golf tee time window may include six separate starting times spaced apart by 10 minutes for each group, so 6 separate items can be associated with a particular time window. [0032] In still another variation of this aspect of the invention, the access items correspond to a right to play golf at a selected time and at a selected golf facility. In a further preferred embodiment, the access time awarded in the auction at the golf course does not necessarily correspond not a single specific time but rather a window of time which includes multiple potential starting times. The final determination of exact starting times is determined by grouping players according to playing ability so players will be assigned to play with other purchasers of similar capability. This same principle is extendible, of course, so that purchasers with other similar skill capabilities in other fields, or other similar attributes (age, tastes, preferences) can be paired at a common final access time. [0033] A further aspect of the present invention includes an embodiment in which up to N separate items can be bid upon by M separate users submitting M sets of bids, and where M>>N, and such that each user's preferences are considered by examining a highest ranked bid, regardless of whether such bid is a highest bid for a particular item. Again, to facilitate and optimize the auction process, the bid prices for the items, but not the bid rankings by other users, are visible to the bidders during the common auction period. [0034] Another aspect of the present invention more specifically concerns a method of conducting an electronic auction of a group of items within a predetermined auction time period, which method includes the following steps: receiving a plurality of bids from a plurality of potential purchasers, the plurality of bids each including a bid price for an item in the group and a bid ranking for the item; examining the bids to create a set of active bids for the item, the set of active bids being comprised only of bids having a highest bid ranking for the item and corresponding to a subset of the plurality of bids from a subset of the plurality of potential purchasers; creating an ordered set of active bids for the item based on a bid price provided for the bid; determining a minimum winning bid for the item by examining the ordered set of active bids; notifying a corresponding one potential purchaser from the subset of potential purchasers when an associated active bid for the item from the potential purchaser has an associated active bid price below the minimum winning bid; setting a selected active bid in the ordered set of active bids as a winning bid for the item when the selected active bid exceeds the minimum winning bid. [0035] In a variation of this aspect of the invention, the associated active bid is dropped from consideration when the one potential purchaser does not increase the associated active bid price within a predetermined time period. The system then selects a next highest ranking bid as an active bid for a different item in the group for those potential purchasers not obtaining the winning bid for the item. A minimum price set by a seller of the item can also be considered in some variants to determine whether a minimum winning bid exists. [0036] Again, in these variants of the invention, the winning bid is not necessarily determined by reference to which of the bids has a highest bid price for a respective one of the group of items. [0037] An auction processing engine comprising another aspect of the present invention operates to conduct an electronic auction by identifying a set of highest ranked bids from bids made by bidders for the item; designating the set of highest ranked bids as active bids for the bidders; determining whether any of the active bids are a potential winning bid for the item by comparing the active bids against each other and any previously determined winning bid; designating any active bid that is a potential winning bid as a winning bid; deleting any active bids that are not designated as a winning bid; repeating some of the above steps during an auction period until no active bids remaining that are higher than the winning bid. [0038] One variation of the auction engine also calls for the same to perform one or more of the following additional steps: notifying a bidder if an active bid for the bidder is not a preliminary winning bid, and specifying a re-bid period for the bidder to increase the active bid; accepting a new active bid from a bidder during the re-bid period, which new active bid has a higher bid price than an earlier active bid from the bidder; designating a next highest ranked bid from the bidder as an active bid for another item when the bidder does not increase the active bid during the re-bid period. [0039] Again, in a preferred approach, any active bids for an item are designated without regard to a bid price of the bids. The auction engine can simultaneously auction a plurality of items, each with a set of corresponding active bids at the same time to determine a plurality of winning bids. A winning bid is determined by examining a highest bid price taken from the active bids, not a highest bid price taken from all bids on the item. Again, in various incarnations of the invention, each bidder can submit a plurality of bids for a plurality of items, but at most only one of the bids is declared a winning bid. [0040] Still another aspect of the present invention relates to a more particular method of auctioning mutually exclusive items, by performing the following operational steps using a computing system configured for such purpose: receiving a listing of a plurality of mutually exclusive items from a plurality of sellers; receiving a plurality of ranked bids from a plurality of users on the plurality of mutually exclusive items; identifying a plurality of highest ranked bids for each of the plurality of users; tagging the plurality of highest ranked bids as active bids; using only the active bids to determine a plurality of preliminary winning bids for the plurality of mutually exclusive items; tagging the plurality of preliminary winning bids; eliminating all non-winning bids; identifying a plurality of next highest ranked bids for each of the plurality of users not obtaining a winning bid; designating the plurality of next highest ranked bids as active bids; comparing only the active bids and the winning bids; identifying a new preliminary winning bid for each of the plurality of mutually exclusive items and tagging the new preliminary winning bid; processing the plurality of ranked bids during a bidding period until all of the plurality of users have either a winning bid or no remaining active bids; and transmitting the results of the auction to the plurality of users. [0041] In other variations of this aspect of the invention, the ranked bid is made to purchase a mutually exclusive item usable by a group of two or more individuals (such as a group of golf players). New ranked bids may be submitted any time before an end of the bidding period. A notice is conveyed to a user if an associated user current active bid is designated a non-winning bid, the notice giving a prescribed time frame to increase the non-winning bid. The non-winning bid is declared a non-active bid if the user does not increase the bid during the prescribed time frame. [0042] A further aspect of the present invention includes a system for conducting an electronic auction of items, which system includes an auction controller accessible by a number of bidding computing systems; an auction inventory database accessible by the auction controller, and being adapted to store identifying information for the items; and an auction bid database accessible by the auction controller, and being adapted to store information for bids on the items, each of the bids including both a bid price and a bid ranking for an item. The auction controller is configured such that it processes the bids for the items in accordance with both the bid price and the bid ranking for the items as noted above. [0043] A variation of this aspect of the invention includes one or more of an e-mail processor for notifying bidders of results of the electronic auction, and/or an administrative computing device for performing administrative tasks for the auction controller. The bidding computing systems (a desktop computer, a notebook computer, an intelligent terminal, a PDA, a cell phone, or some other device) is connected through a network to the auction controller. [0044] Still a further aspect of the invention relates to a system for conducting an electronic auction of items where the system includes: an electronic auction file for storing information concerning auction items; an electronic bid file for storing a set of bids for a corresponding set of items selected from the auction file, each bid in the set of bids including at least a bid price and a bid ranking for an item; and an electronic auction processor for processing the set of bids based on both the bid price and the bid ranking for the corresponding set of items to determine if there is at least one winning bid for one of the corresponding set of items. The system is set up in accordance with the discussion above so that a user can bid on more than one item in the electronic auction, but the electronic auction processor will only generate at most a single winning bid for the user. [0045] Another aspect of the invention relates to a system for participating in an electronic auction which includes a set of N items stored in a database of items available for auction, the set of N items being characterized by a common auction expiration period; a bid input interface for entering a set of N bids for the set of N items, the bid input interface constraining the set of N bids such that at least one one unconditional bid is provided for one item in the set of N items, and the remainder of the set of N bids are comprised of conditional bids for a remainder of the N items; and an auction processor coupled to the database of items and the bid input interface, and being further adapted to process the set of bids prior to the common auction expiration period to determine if there is at least one winning bid in the set of bids, the processing being performed such that the conditional bids are not considered unless the unconditional bid for the one item is unsuccessful, and such that at most only a single item from the set of N items is matched to a single one of the set of N bids when determining the at least one winning bid. In this manner, a user can control the bidding process and be assure of obtaining at most one item from an auction inventory. [0046] A further aspect of the invention concerns a system for participating in an electronic auction which includes a database of auction items, the auction items including first auction items available for bidding during a first auction period, and second auction items available for bidding during a second bidding period; a bid input device for transmitting a first bid for one of the first auction items and a second bid for one of the second auction items, the first and second bids being received from a single bidder prior to an expiration of the first auction period; and an auction processor coupled to the database of auction items and the bid input device, and being further adapted to determine if the first bid is a winning bid prior to the expiration of the first auction period; and being further configured to process the second bid when the first bid is finally determined to be not a winning bid. In this manner, a user can participate in more than one auction, and have his/her bids rolled over to a succeeding auction in the event of an unsuccessful effort during a first auction. [0047] Still another aspect of the invention pertains to an internet based system for allowing a web user/purchaser to bid on a right to play golf at a selected time and at a selected golf facility in an electronic auction. The system includes: a query interface for presenting a list of available golf playing opportunities to the purchaser, the golf playing opportunities including information identifying both a golf course and a time at the golf course available for playing golf; a bid interface adapted to allow the purchaser to enter a bid for each of the one or more golf playing opportunities, the bid including both a bid price and a bid ranking for each of the one or more golf playing opportunities, so that a set of purchaser bids are created for the one or more golf playing opportunities; an auction processor for processing the set of purchaser bids, along with third party bids for the one or more golf playing opportunities, to determine winning bids for the golf playing opportunities; and an e-mail notification system for notifying the purchaser when a currently highest ranked bid from the purchaser is determined to be a winning bid or when the currently highest ranked bid is determined to be not a winning bid. The auction processor is located on an online accessible server, and is configured: 1) to allow the purchaser to increase the bid price for the highest ranked bid within a predetermined time period when the highest ranked bid is determined to be not a winning bid; 2) to evaluate new bids until the end of the common expiration period, and until all of the purchaser bids are determined to be not winning bids, or until one of the purchaser bids is determined to be a winning bid. Using such system, a purchaser is permitted to bid on multiple golf playing opportunities using the set of purchaser bids, but at most only a single one of the set of purchaser bids is satisfied as a winning bid. [0048] A related aspect of the present invention deals with an electronic auction program for processing auction bids for an item. This program is preferably executed at least in part at a remote server destination site, and partially at a user client side site. The program includes a first program portion for identifying a set of highest ranked bids from bids made by bidders for the item, and for designating the set of highest ranked bids as active bids for the bidders; a second program portion for determining whether any of the active bids are a potential winning bid for the item by comparing the active bids against each other and any previously determined winning bid; a third program portion for designating any active bid that is a potential winning bid as a winning bid; a fourth program portion for deleting any active bids that are not designated as a winning bid; and a fifth program portion for coordinating the first program portion, the second program portion, the third program portion and the fourth program portion during an auction period until no active bids remaining that are higher than the winning bid. [0049] By preferably locating the electronic auction program at a computing system accessible by a plurality of user computing devices, this increases the exposure and likelihood of obtaining reasonable bids for the auction items. Thus, the computing system is preferably a server accessible on the internet, and the user computing devices include web browsers for interacting with web pages on the server for entering the bids. [0050] Another related aspect of the present inventions includes a web based auction system interface configured for performing I/O operations between a bidder and an auction system through a browser. This web based interface includes: an auction query interface that is adapted for viewing auction items and receiving user queries through the browser concerning the auction items, and further for retrieving one or more of the auction items in response to such user queries; and an auction bid entry interface that is adapted for receiving user bids for the auction items, the auction bid entry interface including both a bid price entry field and a bid ranking field for any auction item that receives a user bid. [0051] A variation of this aspect further includes an auction status interface for monitoring progress of an auction for the auction items during an auction period. Furthermore, the auction bid entry interface is coded so that the user can enter a plurality of bids on a plurality of auction items, with each of the plurality of auction items receiving a different ranking from any other of the plurality of auction items. This interface further allows a user to enter bids which carry over from a first auction to a second auction when the bids are not successful during the first auction. [0052] Still another aspect of the invention concerns an internet accessible electronic auction site configured for coordinating transactions between a bidder and an auction system. This internet accessible electronic auction site includes: means for accessing auction items available for bidding; an auction query interface adapted for viewing within a web browser and configured for receiving user queries through the browser concerning the auction items, and for retrieving one or more of the auction items in response to such user queries; an auction bidding interface adapted for viewing within the web browser and configured for receiving user bid entries through the browser concerning the one or more auction items, the auction bidding interface including at least a first field for receiving a bid amount and a second field for receiving a bid ranking for each user bid entry; and an auction controller for processing the user bid entries to determine winning bids for the one or more auction items. As indicated above, this system, too, as with the others, is capable of simultaneously auctioning all the items at the same time. [0053] Another aspect of the present invention is directed to a more particular electronic auction system that comprises: means for entering auction inventory items; and means for storing the auction inventory items; and means for reviewing the auction inventory items; and means for querying the auction inventory items to create selected auction inventory items satisfying selection criteria of a potential buyer; means for entering a bid amount and a bid ranking for one or more of the selected auction inventory items to create one or more bid entries; means storing the bid entries; means for processing the bid entries to determine winning bids for the auction inventory items, the winning bids being based on both the bid amount and the bit ranking; means for transmitting a notification associated with the winning bids to one or more bidders. [0054] In another variation, one or more of the following sub-systems are also included to enhance the appeal and utility of the system:means for coordinating payment of any winning bids; means to observe a status of any auctions; means to store user information; means to store vendor information; and means to store and retrieve historical auction results so that users can better understand the auction process, and more intelligently formulate bids appropriate for a particular inventory item. [0055] An advantage of the invention is that it allows a user to enter bids on multiple, mutually exclusive items yet only receive the item corresponding to their highest ranked, winning bid. Yet another advantage of the invention is that it increases the probability of any one item receiving at least one bid, thus maximizing returns to sellers of such items. [0056] The referenced system provides a highly advantageous manner to simultaneously auction mutually exclusive items. Mutually exclusive items may either be multiple items that physically cannot be possessed simultaneously or they may be more than one item that the user would not wish to simultaneously possess. This system allows the user to enter multiple, rank ordered bids that are sequentially processed. This allows the user to effectively bid on a large number of items while only receiving the item corresponding to their single, highest ranked, winning bid. This method increases the probability the user will successfully bid for one item; decreases the probability the user will be out bid at the last moment of the auction on all items of interest; significantly reduces the incentive for entering a slightly higher bid than the current winning bid at the last moment; and, significantly decreases the amount of auction involvement required by the user. [0057] This method also benefits sellers by increasing the probability of receiving at least one bid for their item and increasing the expected winning bid amount. Consider the following case. Three bidders are bidding on three nearly identical, mutually exclusive items. All three bidders place their bids moments before the end of the auction. If all three bidders bid on the same item, two of the items receive no bids. If all three bidders place bids on all three items and rank order their preferences for each item, the bids can be processed such that each bidder receives at least one item. Assuming nearly equal preference for the three items by all three bidders, this new outcome is much preferred to the case where all three bidders bid on the same item. In the present example, all bidders receive nearly the same utility from the items they won and all sellers sold their items. This contrasts sharply with only one successful bidder and only one successful seller in the baseline example. [0058] Thus, one significant benefit of the present invention lies in the fact that mutually exclusive items are included in the same auction or the items may be bid upon in successive auctions. In the latter case, the rank ordering of the items is constrained such that the auction closing date for each successively ranked item is the same or later than the auction closing date of the preceding ranked item. BRIEF DESCRIPTION OF THE DRAWINGS [0059] FIG. 1 depicts a preferred embodiment of a system for auctioning mutually exclusive items utilizing the present invention [0060] FIG. 1A shows a preferred electronic format of an auction item used in the electronic auction system of the present invention. [0061] FIG. 1B illustrates a preferred format for an auction item of the present invention; [0062] FIG. 2 is a flow chart demonstrating a preferred method used by an auction processing engine to auction mutually exclusive items with the present invention. [0063] FIG. 3 is an example showing an exemplary bid and rank order listing table for a prospective bidder. [0064] FIG. 4 is an exemplary auction cross reference table showing three items and three users with their bids and rank orderings displayed. [0065] FIG. 5 is an exemplary table indicating the outcome of the auction shown in FIG. 4 . [0066] FIG. 6 is a preferred embodiment of a user query interface screen showing auction search input data fields. [0067] FIG. 7 is a preferred embodiment of a user search results interface screen showing auction search output data fields. [0068] FIG. 8 is a preferred embodiment of a user bid entry interface screen showing a completed bid entry page. [0069] FIG. 9 is a preferred embodiment of a seller auction inventory input screen. [0070] FIG. 10 is a flow chart demonstrating the general method used by a user to identify and bid upon mutually exclusive items in the present invention. DETAILED DESCRIPTION OF THE INVENTION [0071] A detailed explanation of the preferred embodiments is now provided as illustrated in the drawings and discussed herein. [0072] FIG. 1 shows a preferred system 10 for the auction of mutually exclusive items. As described herein, while a preferred embodiment uses a particular tee time at a particular golf course as the “item” for auction, it will be understood that the term is intended in its broadest sense, and the invention is not limited in this respect. Thus, an “item” can refer to any number of tangible articles and intangible properties, or to a right of access or use to a particular facility (such as a travel seat, hotel room, restaurant seat, concert seat, etc.) Moreover, the term “mutually exclusive” in this regard is meant from the perspective that a would-be purchaser is perhaps only interested in owning one of the items (i.e., such as only one tee time on a particular day) even if he/she bids on more than one item at a time, and/or that it is not possible to own more than one item at a time because they are inconsistent, incompatible, etc. (i.e., such as owning the same tee time at two different locations). [0073] A Central Auction Controller (CAC) 100 manages all data input and auction bid processing for any items that are involved in an electronic auction. Any number of sellers can enter item inventory for auction and view auction status and results using I/O devices 105 , 115 which are attached to computers 110 , 120 that exchange data with CAC 100 . The sellers login to an electronic auction system 10 using their respective I/O devices and CPUs 105 , 110 , 115 , 120 which transmit necessary login information to CAC 100 . CAC 100 verifies seller login information or allows the seller/vendor to establish a new vendor account in one or more databases represented by database 155 , such as vendor database 170 . Once logged into system 10 , sellers may list inventory for auction using I/O devices 105 , 115 and their respective CPUs 110 , 120 . Seller CPUs 110 , 120 thus transmit auction inventory information to CAC 100 where is it stored in an auction database 165 . Sellers may also query CAC 100 regarding results of previous auctions, and can request that CAC 100 retrieve auction results from auction database 165 and transmits the same back to the sellers. The I/O devices 105 , 115 and CPUs 110 , 120 used by the Sellers can consist of conventional modem communication devices, personal computing systems, and devices which combine such functionalities (i.e., such as a PDA). Preferably, of course, the Sellers can access CAC over a network, such as the Internet, using a conventional browser viewing a website page (not shown) maintained and controlled by CAC 100 , or through a wireless network connection as provided by an intelligent cell-phone, PDA, etc. [0074] Potential purchasers of the items for auction can view open auctions and review the results of previous auctions using the I/O devices 125 , 135 which are attached to computers 130 , 140 that exchange data with the CAC 100 . These devices can be of the same type as used by the Sellers noted above. Again, too, prospective purchasers are preferably given access to auction data over a conventional Internet link and using a conventional browser to maximize the availability of the auction information, or through a wireless network connection as provided by an intelligent cell-phone, PDA, etc. Users login to system 10 using I/O devices 125 , 135 and their respective CPUs 130 , 140 , which transmit appropriate login information to CAC 100 . CAC 100 verifies user login information or allows a user to establish a new user account in user database 160 . Once a user is permitted access into system 10 , they can submit an auction inventory query and thus cause CAC 100 to search auction database 165 for inventory that meets user input query parameters (defined in more detail below). The CAC 100 transmits the auction search results for display on the user I/O devices 130 , 140 . Inventory included in the searchable database may all have the same bid closing date and time. However, the inventory available for bids may also have different bid closing dates. In the case of different bid closing dates, the rank ordering of the items must be such that the auction closing date for each successively ranked item is the same or later than the auction closing date of the preceding ranked item. [0075] System users enter bids for auction items on their respective I/O devices and CPUs 125 , 130 , 135 , 140 that are transmitted to the CAC 100 . These bids (which include more than just price information as discussed in more detail below) are stored in auction database 165 . CAC 100 processes bids as they are received, and sends notifications to users via an e-mail processor 175 . Upon close of an auction bid time window, CAC 100 processes all outstanding bids and determines any winning users for each of the auction items. [0076] Administration of the auction process is performed through I/O device 145 attached to administrative computer 150 that exchanges data with CAC 100 . As noted earlier, CAC 100 stores and retrieves relevant user, auction and vendor data from databases 155 , which databases may be located at one server, or potentially many different servers accessible to CAC 100 . In particular, user database 160 stores registration data for system users, such as names, addresses, identification numbers, payment information, etc. A system administrator can login to system 10 to check the status of current auctions, to update user or vendor information or perform other normal maintenance of the system via their I/O device and CPU 145 , 150 . [0077] Auction database 165 stores records of the inventory of items available for bid, current bids and results of previous auctions. Seller database 170 stores registration data for sellers, including names, addresses, and any other desired information appropriate for the item inventory. CAC 100 also controls an e-mail processor 175 , which, as noted above, is configured to send messages to users, sellers and an administrator, to inform them, for example, of item auction status, reminders, item particulars, etc. [0078] The particular details of the hardware described above are not material to the present invention, and therefore are not discussed at length here. It will be understood by those skilled in the art that any number of different commercially conventional computing systems could be configured in an appropriate and conventional fashion for the purposes needed to achieve the present objectives. [0079] FIG. 1A shows a preferred electronic format of an auction item 178 used in the electronic auction system 10 of the present invention, which includes at least an ID field 180 for uniquely identifying a particular item. As discussed earlier, an “item” in the preferred embodiment represents: (1) a right of access to enjoy some activity (in this case to play golf indicated by an item descriptor field 181 ; (2) at a particular location (golf course) indicated by location field 182 ; (3) at a particular time (tee time) indicated by time field 183 ; (4) for a particular duration indicated at duration field 184 ; and finally (5) a quantity of the items available at quantify field 185 (defining the size of the group of item(s) which can be a numerical value greater than or equal to 1). Thus, for each item (or group of items), information for at least these five parameters are presented to a user during the bidding process, as seen in FIG. 1A . Furthermore, each item will typically have associated with it an auction expiration date field 186 , which defines an auction time window in which bids will be processed from various users. An additional minimum price field 187 a is used to set a minimum bid price for the item, if that is desired. A reserved price field 187 b designated “guaranteed price” might be used in some applications, which can represent a numerical value for which if a bid is received, the user is guaranteed to receive the item in question without further bidding. This option might be of use, for example, so that sellers can set visible reserve prices. Additional fields for other administrative information (such as payment requirements, spacing between tee times, group sizes, etc.) can be provided in additional fields (not shown) as desired based on the nature of the particular item, system, etc. [0080] A user bid entry 179 is shown in FIG. 1B . This includes a user ID (field 188 a ) user bid price (field 188 b ) and ranking (field 189 ) and optional information (field 190 ) are also provided and are filled in by the individual bids provided by users as indicated below. Other information relevant to such bid entry 179 (i.e., such as the item ID number 180 , a user's maximum bid price, a user's skill level, etc.) is not shown here but are understood to be implicit to the extent they are useful for implementing the benefits of the present invention. [0081] The particular types of fields used in auction item 178 and used in bid entry 179 in any environment will vary, of course, from application to application, so it will be understood by those skilled in the art that the foregoing is merely the preferred approach used in the present embodiments. [0082] In the case where all displayed inventory items have bid on by the user have the same auction expiration date 186 , the values entered in the ranking field 189 for any particular bid may follow any desired order. However, in the case where the auction expiration dates 186 are different for the selected inventory bid on by the user, the values entered in the ranking field 189 are preferably constrained to simplify the auction process. In the preferred embodiment, a ranking for an item in an earlier auction closing date must always be higher (more preferred) than any ranking given to an item in a later auction closing date. This is done to ensure that all bids for each auction will be resolved before the next auction closing date. This approach thus guarantees that at any moment in time the pool of outstanding bids consists of only the set of highest ranking bids from each user and that no bid more preferable for any user is being ignored. [0083] Some users of the present invention on the vendor side may wish to have an item correspond to multiple, rather than single rights of access, so that, for example, an item might represent a tee time for four players, rather than one, so that the inventory can be packaged and managed in this fashion instead. [0084] Already one significant difference to the prior art is apparent, in that the “items” 178 and bid entries 179 of the present invention are distinct from the access rights auctioned at some prior art electronic auction sites where, for example, the user is only permitted to specify a date, and then an embarkation location followed by a disembarkation location. There is no ability to control or specify a particular seat, or even a particular flight in the prior art system. Of course, additional information could be specified for the item depending on the environment in which the invention is practiced, and it is expected that some degree of routine fine tuning will be necessary to optimize the capabilities and performance of any such system. [0085] FIG. 2 illustrates a method used in a system implementing the preferred embodiment. For any particular item 178 listed for inventory in an electronic auction system 10 , the system processes submitted “bid” information from entries 179 at step 205 , which, bid information again, in a preferred embodiment, consists of at least the following information extracted from the participating user formatted bid entries 179 : (1) a numerical value representing the price they are willing to pay for the right to play golf at the particular course and time (in bid amount field 188 b ) and the user ID (field 188 a ); and (2) a ranking representing the user's evaluation of the item relative to other items he/she has bid on in the particular group of items available in inventory (in bid ranking field 189 ). From another perspective, the bids made by the user on a group of items—other than the highest ranked bid which is a form of unconditional bid—can all be considered “conditional” bids in that each lower ranked bid has an existence that is conditioned on the non-fulfillment of the user's next highest ranked bid. The use of such conditional bids, therefore, is a new feature introduced by the present invention which allows an easy and flexible experience for the user, especially when used in conjunction with unconditional bids. [0086] Again, in other environments it is possible that other user information might be collected as part of the bid in optional field 190 , such as a time limit expiration for the bid, a maximum value the user is willing to bid, an auto-bid feature, and similar types of data. For purposes of the remainder of the discussion below, these three fields 188 , 189 and 190 define the “bid” as offered by the user. However, some additional fields, including Active/Inactive Bid field 191 and Winning/Non-winning Bid field 192 are used by CAC in connection with each user bid as explained below. Initially, these status fields, or tags, are preset to Inactive and Non-winning respectively for each bid submitted to CAC 100 . [0087] CAC 100 is continuously monitoring for new bids on items, and adjusts a status for an auction item whenever a new bid is received within the auction time window, and at the auction expiration time. Thus, at step 210 it reviews all user bids and for each user tags a highest ranked bid (i.e., the bid with the highest value in field 189 for the particular user) with a designation Active Bid by setting flag 191 for the bid. At 215 , all bids set as an Active Bid or as a Winning Bid for an item (or group of items) are put in a first grouping, and ordered from highest to lowest for a particular item. Again, because an item may be able to accommodate more than one user (i.e., it may represent four separate tee opportunities at the same time, or there may be an indication that there are four times available in the item quantify field 185 so that there can be four winning bids), there may be more than one winning bid per item. Thus, the present invention accommodates situations where items can be grouped (depending on how similar they are) and be auctioned together. If the inventory is listed for auction in blocks of multiple similar items, the number of items in the block determines the number of winning bids, which thereby sets the minimum winning bid level 217 . If there is only one item in each inventory block, the minimum, winning bid will be equal to the highest Active Bid. Thus, a Minimum Winning bid value is determined at step 217 by ranking all ordered Active Bids and Winning Bids and selecting a bid value that is equal to that bid from this set that corresponds to the xth from the top, where x represents the number of items. Thus, the bid in the xth sorted position represents the lowest possible winning bid for one of the x items; again, in some situations, x may be equal to one. [0088] At 220 a determination is made as to which if any of the ordered Active Bids and Winning Bids are higher than the Minimum Winning bid 220 . If a particular Active Bid is higher than the Minimum Winning bid, such Active Bid is tagged (by setting the Winning bid field) as a Winning Bid at step 225 . In addition, the sorted Active Bids and Winning Bids might be subjected to satisfying a second condition before they are declared Winning Bids, by comparing them to a reserve or minimum bid value provided by the seller. If necessary (depending on the number of user bids, and the number of items in the group for auction) the older lowest bid that has a Winning Bid designation (which is now supplanted by the newer higher amount in the new Winning Bid is then re-designated as an Active Bid now. If there is sufficient time remaining before the bid window closes, the user who originally provided the re-designated bid is notified at 230 that they have been outbid. Note that, in this regard, typically the “bidding window” available to users to submit bids will be shorter than (or expire before) the auction expiration period, to allow the system to properly handle any last minute provided bids. If the outbid user does not increase their bid within a specified time frame at step 235 , their bid is designated Inactive Bid at step 238 and such user's next highest ranked bid (if such exists) is tagged Active Bid 240 . If the user increases their bid during the available time period, then the bid remains an Active Bid and the maximum bid amount for that bid is increased to the new amount entered by the user at step 245 . If there is not sufficient time before the bid window closes to process/send a notification, the Active Bid expires at the end of the bid window and the user's next highest ranking bid becomes their Active Bid 240 . [0089] A determination is made at step 250 as to whether the bid window has closed by checking field 185 . If bidding for the item is not closed, the bid—now having the designation Winning Bid—is returned to the pool of outstanding bids to be examined and at 215 system 10 again goes through the process of ordering outstanding Active Bids and Winning Bids. If the bidding window is closed, a determination is made at step 255 about whether any Active Bids remain. If such bids remain, step 215 is again repeated. When there are remaining Active Bids, this means that not all Winning Bids have been resolved, and that they must be rendered into Inactive Bids or Winning Bids by the auction resolution process. If no Active Bids exist, the Winning Bid(s) are declared as winners at 260 . Winning bidders may then be notified through e-mail. All bids for the item are considered processed when the highest ranked remaining bid for all users is either set as a Winning Bid or an Inactive Bid. One benefit of the present invention, therefore, lies in the fact that a multitude of items can be resolved simultaneously, and with a multitude of potential winners. Since winners are not notified until the end of the auction time window, there is also no collusion possible between buyers to try and guess or experiment with artificial bids in an effort to glean any reserve price set. [0090] Any Active Bids below the Minimum Winning Bid are thus routed at 220 for further processing if bidding is still open. If a user bid has a Winning Bid status, but is nevertheless lower than the minimum winning bid, such bid is given a designation Active Bid at step 228 by setting such status in field 191 . After step 228 therefore, the only bids that are Active Bids are those that do not exceed the Minimum Winning Bid level. Some time after this, a message is sent at step 230 to notify the user and inform them of a time frame (which may or may not correspond to the end of the bidding period) during which they may increase their current active bid. If the user does not increase the value in field 181 for the Active Bid for the item during the available time window, their Active Bid is then given a designation (by setting field 191 ) as an Inactive Bid at 238 . An Inactive Bid designation represents the fact that it is no longer active, or in the pool of outstanding bids to be considered for the item's auction. Of course, in those applications where a maximum bid amount option is presented to the user (for inclusion in field 190 ), the value specified in this field can be compared first against the Active Bid amount to determine if the Active Bid amount can be increased without resorting to notifying the user. In this fashion, the user can avoid having to re-bid in a controlled fashion below a threshold limit of their choosing. [0091] In any event, if the user does not respond in time, the user's next highest ranked bid then receives the designation tag of Active Bid at step 240 and this next bid is now submitted to the pool of outstanding active bids and again goes through the process of ordering at 215 . [0092] If the user's Active Bid is increased at step 235 within the available defined time window, an Active Bid Amount parameter is increased by system 10 at step 245 to reflect such new amount as set out in field 181 . The now updated Active Bid returns to the pool of outstanding active bids and again goes through the process of ordering at 215 . [0093] At step 250 , a determination is made concerning whether the item's bid window has been closed. If so, all Active Bids for the item are identified at 255 ; at this stage, a resolution of all bids as Winning/Non-Winning, or as Active/Inactive, might not have been finalized. If there are any remaining Active Bids, this means that not all Winning Bids have been resolved, and that they must be rendered into Inactive Bids or Winning Bids by the auction resolution process. [0094] The timing between the close of bidding (i.e., the bid window close) and the determination of final bid results, or auction close, is configured such that there is a sufficient interval between when the last, new bid is accepted by CAC 100 and when the auction results are finalized so that all bids are processed and determined, in the end, to be either Winning Bids or Inactive Bids. [0095] Upon determining the final winning bids 260 , payment for some portion of the winning bid amount may be finalized at step 265 , based on payment information provided earlier by the user (i.e., such as a credit card number) Notifications are sent by E-mail or other suitable means to notify winning bidders 270 . These notifications confirm the commitment for sale by the seller and include information such as the date, time and location of the item, confirmation of the credit card transaction and a confirmation code or other identifying information for verification purposes. [0096] FIG. 3 shows a portion of an exemplary user auction item data input table 300 , which the user may access at any time to see the status of his/her bids. The user interacts with table 300 (as part of an appropriately designed input screen discussed below) and such table contains at least some of the bid information noted above for each item 179 , in bid amount field 188 b and bid ranking field 189 . In its simplest form, user input table 300 is created for each separate user having an ID with the system, and consists of at least three columns of information; it is understood of course that it may include other information relevant to the particular user/system. Item Description column 310 contains an item number or item description for the auction items (which can be obtained from item ID field 180 or item description field 181 ). The Bid column 315 contains a bid amount input by the user for each of the items shown in the first column, as will be used for bid amount field 188 b above. The Rank Order column 320 contains a relative ranking input by the user for each of the items shown in the first column which will be used for bid ranking field 189 noted earlier. As explained earlier, any mutually exclusive items bid on by the user must either all be included in the same auction, or alternatively the items may be in successive auctions. In the latter case, the rank ordering of the items is constrained by the data input entry mechanism such that the auction closing date for each successively ranked item is the same or later than an auction closing date of a preceding ranked item. The rankings are controlled so that they range from one to N, where one represents a highest selection, and N the lowest selection for the N items bid on by the buyer. Again, as explained above, all the bids by the user can be considered conditional bids, in that each is utilized in the auction process/becomes actualized or unconditional only when the immediately preceding, highest ranked bid is declared an Inactive Bid. [0097] The preferred method, therefore, allows two separate constraints (price and rank) to be used for an auction process, as opposed to the prior art, where only a single constraint (price) is used. In the preferred method, no ties are allowed for the ranking process. All items must be ranked relative to each other, and suitable control/filtering logic can be employed to ensure that this is done (through form auto-filling features if necessary) before the user finishes completing data entry. It should be apparent that the data needed from the user for these entries can be provided in any conventional fashion by the user, such as through an interaction with an HTML page, a Java based applet, etc. The individual user input tables 300 in a preferred system are viewable, modifiable, etc., only by the user creating the same for privacy and security reasons. [0098] An important facet of the present invention is that the user is permitted to aggregate or create collections of items representing an expression of his/her bidding desires with ease and flexibility, even across auction window boundaries. These collections of items are not defined by system 10 , but rather, under the control and specification of the user. In this manner, the user is allowed to define a bidding strategy that permits them to obtain at most 1 of the N selected items as a final selection, even across different auctions. In other words, when the user only wants or desires one golf tee time, for example, they are allowed to express and define a multitude of potential choices of dates and times, and propose a bid and ranking for each, even if they occur in different auction periods. This is in contrast to the prior art where, for example, in order to bid on a multitude of items, the user is required to make an irrevocable commitment on each, and in the end, he/she could end up having to purchase more than what they wanted. Furthermore, the user is also constrained in such systems to bid only on one auction at a time, and he/she cannot “roll over” their bid to another auction as in the present invention. In this regard, system 10 is intelligent enough to realize that the user actually only wants one of such choices, and therefore it operates on his/her behalf to find a selection that best matches the particular user's price/ranking constraints, even if multiple auctions must be resolved to satisfy such selection. While the user may not obtain his/her first choice, they are guaranteed that they will not end up with more than one of their selections. [0099] Nonetheless, the present invention has the ability to seamlessly mimic the functionality of the prior art (if such is desired) by allowing the user to define yet another set of items for which he/she wants to bid. From a practical perspective, there is no limit to the number of distinct user input auction tables that can be associated or used by a single user. For example, a user may bid on one collection of items corresponding to a single tee time at a particular course, and a separate collection of items corresponding to a single tee time at a different course. Similar situations could be set up for each distinct group of items the user wishes to bid on. [0100] FIG. 4 depicts how a cross reference table of users and items for an auction can be compiled from the auction items 178 , bid entries 179 , and auction status information gleaned from the aforementioned auction process itself depicted in FIG. 2 . 400 . To simplify the present discussion, in this example it is assumed the auction closing date for all items in the table is the same, but the resolution of cases where they are not the same will be apparent to those skilled in the art from the present teachings. Item descriptions (from ID field 180 and/or other fields 181 - 185 ) are shown in the top row of the table 405 . User identities (from user ID field 188 a ) are contained in the first column of the table 410 . Each cell of the table shows a current bid amount and rank order for each respective item by each respective user 415 . As seen in FIG. 4 , each of Item 1 , Item 2 , Item 3 have received three bids from three separate users, with Item 1 ranked highest by User 1 and User 3 , and Item 3 ranked highest by User 2 . To begin the auction, since User 1 and User 3 have ranked Item 1 the highest and User 2 has ranked Item 3 the highest, these bids would be initially identified, tagged and sorted as Active Bids to be considered when determining a Winning Bid for each item. However, the bid by User 2 on Item 1 , while higher in value than either the bid from User 1 or User 3 , would not be used during the auctioning process of the present method unless it were designated already as an Active Bid for User 2 (i.e., in the event Item 3 had already been auctioned, and User 2 had not received an indication of a Winning Bid). [0101] The auction cross reference tables 400 in a preferred system are viewable, modifiable, etc., only by a system administrator for privacy and security reasons. However, it may be desirable and in fact advantageous to permit individual users to see the status of particular auction items in some fashion in order to optimize the bidding process. While the specific types of visual output for the users are discussed in detail below (in connection with FIGS. 6, 7 , 8 , 9 and 10 ), it can be noted even generally at this point that to control the dynamics of the bidding process, a variety of choices concerning the information presented to the participants from auction items 178 , bid entries 179 and the auction status can be effectuated to influence the behavior of the participants and thus optimize the sale of the inventory and the satisfaction of the auction participants. For example, it might be desirable in some cases to control shielding of the identity of the auction participants, to discourage collaboration/manipulation of the auction process. Furthermore, it might be desirable to control what bids are shown for an item. As an example, the system may allow only the highest ranked unconditional bid for an item to be seen by the auction participants, rather than the highest ranked overall bid (conditional or unconditional) for an item. In addition, it might be beneficial to provide at least some information about the number of conditional bids for an item, and their bid value, again to help inform users and motivate them to bid appropriately for items. Information on a user by user basis (such as the value of an unconditional bid, the number of unconditional bids, etc.) may or may not be provided to other users. These are but example, of course, and it should be apparent that any one or more of these controls, some variation/combination, or some other control might be used to better stimulate and maximize the bidding process for any particular auction environment. [0102] Thus, in a preferred embodiment of the present invention, while the highest unconditional bid information is available for viewing by users for the individual items, the ranking information of each user is preferably not made visible. Therefore, there is no mechanism in the preferred embodiment by which User 1 and/or User 3 can know that it is User 2 's bid, and/or that it is only a second-ranked (conditional) bid. Instead, such users see only that there is at least one unconditional bid that is as high (or more) than the highest ranked unconditional bid, and will have to take this figure at face value as a potential Active Bid for the item unless User 2 is satisfied by some other auction item (i.e., such as Item 3 ) and thus drops out of consideration for Item 1 . This is because they do not know whether the bid by User 2 on this item might be processed because the latter's unconditional bid on another item might not be satisfied. In this fashion, therefore, bidding for items is maximized from the perspective of the seller, since many more bids are obtained and processed. Even if some of them ultimately may not materialize into real purchases because they are only conditional bids, their mere existence is enough to increase the demand for the item, and thus the potential bid price. To prevent bid manipulation, the various user bids can be made non-retractable, so that users cannot reduce their bids if it turns out that a potential co-bidder is eventually eliminated. For example if a user 1 submits a bid at X+1$—because he/she sees a bid at X$ by user 2 —user 1 is preferably not allowed to change the bid (or ranking) later to take advantage of user 2 's withdrawal. In the preferred embodiment, a graphical representation indicates the number and amount of bids that are not currently Active Bids or Winning Bids and clearly indicates the status of conditional and unconditional bids. For example, the table may indicate the number of next highest ranked bids for all system users that are as high or higher than the current winning bid amount. As a further refinement, the system may show the number of bids exceeding the current winning bid versus the relative rank order of the bids (i.e., by grouping the bids based upon whether they are the next highest ranked bids, two rank orders higher, three rank orders higher, etc.). [0103] FIG. 5 illustrates in more detail how an auction process illustrated in FIG. 2 of the present system would utilize an auction outcome table 500 to determine and record the outcome of the various bid entries entered in auction cross reference table 400 in FIG. 4 . The item IDs are shown in the first row 505 and the user IDs are listed in the first column 510 . For simplicity, it is assumed that no bids are increased and that Item 1 , Item 2 and Item 3 are to be auctioned simultaneously with the same auction closing. In this example, system 10 first tags user bids ranked highest (i.e., with a #1 rating) as Active Bids; thus, bids 515 , 540 , 545 are initially designated as Active Bids. User 1 's Active Bid 515 is tagged Winning Bid because it is higher than user 3 's Active Bid 545 . User 2 's Active Bid 540 is tagged as a Winning Bid because there are no other Active Bids or Winning Bids for Item 3 . User 3 is notified they must increase their Active Bid for Item 1 . In this scenario if no bid is increased, User 3 's Active Bid 545 is tagged as an Inactive Bid and User 3 's second ranked bid 560 is now tagged Active Bid. [0104] In a second iteration, User 3 's second ranked bid 560 is tagged as a Winning Bid for Item 3 because it is higher ($13) than User 2 's first ranked bid ($12) for Item 3 . User 3 's second ranked bid has previously changed from a purely conditional bid to an actual bid at step 210 ( FIG. 2 ). At this point, nothing has changed for Items 1 and 2 , so they are not considered in this iteration. User 2 's bid 540 for Item 3 is now re-designated from a Winning Bid to Active Bid. User 2 is notified they must increase their bid, or potentially lose Item 3 . Again, in the event of no increases, User 2 's Active Bid 540 is tagged as an Inactive Bid and their second ranked bid 530 for Item 1 is now tagged as their Active Bid. In other words, as for User 3 earlier, User 2 's second ranked bid (which was only conditional before) becomes converted into an actual bid for the auction process. [0105] In a third iteration, User 2 's second ranked bid 530 for Item 1 is tagged as a Winning Bid because it is higher than User 1 's first ranked bid 515 . User 1 's first ranked bid 515 is tagged Active Bid and a notification is sent to increase the bid. Assuming no increase, User 1 's Active Bid 515 is tagged Inactive Bid and their second ranked bid 520 is tagged Active Bid. [0106] In a fourth iteration, User 1 's second ranked bid 520 for Item 2 is tagged as a Winning Bid because it is the highest, and only outstanding, Active Bid on Item 2 . The auction for all three items is now completed because all three users each have a bid that is tagged as a Winning Bid. As a final result, User 1 is declared the winner for Item 2 , User 2 is declared the winner for Item 1 , and User 3 is declared the winner for Item 3 . Thus, the auction process for the group of items is resolved with reference to considering both the items and bids collectively at the same time, rather than on considering only one item at a time, or one bidder at a time. [0107] While the situation involving an increase in bid is not discussed specifically above, it is apparent that this event merely requires yet another iteration to be processed for the item in question. Some observations can be made about the bidding process of the present invention, including the following: (1) An item does not necessarily go to the user submitting the highest bid (see e.g., Item 2 ) since there is an extra dimension of ranking involved which modifies the auction behavior and resolution process. Nonetheless, assuming no minimum bid amounts, whenever the number of bidders exceeds the number of items and every item is given the highest possible ranking by at least one user, each item should be successfully auctioned. While it is possible that an item might not be the subject of a successful bid if it is not given the highest possible ranking by at least one user, this could be avoided by requiring that every user make a bid, even a conditional one, on every item in the group. Even if the bid is very low, this approach at least guarantees to the seller that the inventory will be disposed of, and encourages buyers to make higher bids for the items they really want (to avoid being forced to accept their lower ranked selections). (2) The existence of many bids (the unconditional highest ranked bid and the lower ranked conditional bids) can result in a higher overall winning bid when at least some outstanding bid information is presented to users (see, e.g., Item 3 , where the bid by User 1 can influence the bids by User 2 and User 3 ) thus increasing the profitability to the seller,. (3) While the seller's profitability is increased because bidding is encouraged on multiple items (since the user is only accountable for one item in the end he/she feels more at liberty to put in a bid for more than one item) the resolution of the auction is done in a manner that considers first the ranking constraints provided by the users, rather than the pricing parameters set out by the bidder or those associated with the item. In other words, the process is driven from the perspective of finding a winning bid for each user based on their highest ranking, and he/she is allowed to change this bid as needed to maximize their satisfaction and price constraints. (4) The types of items that can be auctioned simultaneously can be expanded to include such things as those involving access of some kind, such as transportation (airplane, train, bus, etc.) seats, restaurant seats, theatre/concert seats, sporting event seats, and/or to groups of similarly related tangible articles such as collectibles, coins, stamps, books, antiques, recordings, paintings, furniture pieces, clothing, jewelry, automobiles, appliances, electronic devices (computers, stereos, VCRs, TVs, cameras, etc.) real properties, office materials, food, and other consumer staples and/or to groups of similarly related tangible articles such as grains, chemicals, packaging containers, wood pulp or other industrial raw materials and/or to groups of similarly related industrial things such as those involving access of some kind, such as freight transportation (airplane, train, truck, etc.), pollution permits, water rights or other such industrial requirements. (5) The process can be extended to N items logically grouped in some fashion, and M separate users competing for this group, so that each of the N items is the subject of a corresponding single Winning Bid from one of the M users. This type of auction situation is not easily (if at all) resolvable using prior art techniques, and yet the present invention accomplishes a fair result that is appealing to both buyers and sellers. Moreover, it allows a user to enter a bid for a single item that may be handled across multiple successive auctions, and thus allow the user more flexibility and control for ultimately satisfying a particular item need. By automatically rolling over the user's highest ranked bid to an item in a successive auction, the user is guaranteed ongoing participation with a minimum of interaction/monitoring and involvement. [0113] In a related variation, to smooth out the computational load on CAC 100 , system 10 can restrict and categorize an inventory of items so that during any particular period, a predetermined number of items are resolved on a regular basis. For example, it is probably better to schedule a resolution of 100 items daily, rather than 700 items at the end of the week. Using a number of conventional programming techniques, the inventory can be controlled and managed so that users cannot overload a particular resolution period with too much inventory. [0114] FIG. 6 depicts a preferred user item search input screen as it would appear within a user's browser loaded with a web page containing data entry fields that are appropriately configured to participate in locating inventory items 178 in an auction search from databases 165 and 170 ( FIG. 1 above). To conduct a search, the user first selects a range in date entry field 610 corresponding to the dates on which they wish to play. The user inputs a region in region entry field 620 which they wish to review available tee times. Finally, the user inputs the number of players in their group in group size entry field 630 . The number of players in their group may be different then the golf courses' normal group size. For example, a user may have a group of two people, themselves and one other person. However, golf courses normally send out groups of four persons. In this case, the user would normally expect their group, if they successfully bid, to be paired with two additional golfers. Other environments where the invention is used may or may not have such groupings, of course. [0115] After inputting the necessary information, the user submits their search criteria by pressing a Search command button 640 . Results of the search are displayed on a new page, in the form of a search results page 700 , as illustrated in FIG. 7 generally. [0116] FIG. 7 illustrates a preferred embodiment of a user search results page 700 as it also would appear within a user's browser. In this example, the search result page is specifically tailored to display searches of available golf tee times from available auction items 178 matching the user's criteria. Page 700 displays the search criteria including a date range 705 and group size 710 corresponding to the user's selection. In addition, search results page 700 includes a number of data fields visible to the user, which, as mentioned above, can be tailored to display various types of information adjusted to the specific needs, desires, design goals, etc. of a particular auction system. In the present preferred embodiment, page 700 includes at least an auction closing date indicator for the selected display times in field 715 . In this instance, the specified auction closing date in field 715 is the same for all displayed times. However, it is possible, as mentioned earlier, to have multiple auction closing dates for the available inventory. Search results page 700 also shows a golf course name in field 720 , a date of an available time for each item in field 725 , a time window for the item in field 730 , a number of inventory items available in such time window of the size specified by the user in field 735 , a minimum acceptable bid or reserve price in field 740 , a current winning bid level in field 745 (which, as noted above, is preferably the highest unconditional bid), selection fields 750 for each available inventory item, a guaranteed price in field 755 indicating an amount which the use can bid so as to guarantee purchasing an item without further processing in the auction process described earlier and an purchase selection button 760 that allows the user to immediately buy the inventory item at the price specified in field 755 . [0117] The user has three options from search results page 700 . They can return to search criteria input screen 600 by pressing a conventional back button on their browser and change their search criteria if desired. Or, they can immediately purchase a tee time within one of the time windows by pressing Buy Now button 760 next to an inventory item of their choice. Or they may elect to enter the auction process by selecting one or more inventory items for bid by selecting the respective selection buttons in field 750 next to the item of interest 750 . Upon selecting one or more items for bid, the user submits their items of interest for bid entry by pressing Submit button 765 . [0118] FIG. 8 depicts a preferred embodiment of a user bid entry page 800 as it would appear within a user's browser, and as used to create bid entries 179 , table 400 , etc. Again, in this embodiment the user bid entry screen is tailored specifically for entering bids on golf tee times. This page combines some of the results from a search of all available tee times as shown earlier in FIG. 7 , based upon the user-defined parameters selected there—i.e., by the user's selection in field 750 of the top three items in screen 700 . With reference to FIG. 8 , the use of like numerals here is intended to represent the corresponding feature from earlier figures unless otherwise noted. For example, date range 805 , group size 810 and auction closing date 815 are the same as noted above for their counterparts. Similarly as for FIG. 7 , for each line item, screen 800 displays tee time window date 825 , golf course 820 , desired tee time time window 830 , minimum bid 840 , and current winning bid amount 845 . The new display fields in this screen include, however, a a first field 846 identifying a number of conditional bids higher than current winning bid (which can be gleaned easily with reference to the auction items 178 and user bid entries 179 ) and two additional fields for user bid input at 848 and 849 . Other potential entry fields, such as for specifying personal data about the user (payment information, skill level, etc.) are not shown, but, of course, could be implemented in any conventional fashion. [0119] The first bid input field 848 is provided for the user to identify a maximum bid for each tee time window that they bid on. The second bid input field 849 is provided for the user to identify a rank ordering of the items, in this case, the tee time windows. As noted earlier, this input capture screen 800 ensures that the rank ordering provided by the user is constrained such that each tee time window has a unique rank in field 849 . The ranking can be provided in any convenient form, and in the present example, textual descriptions are used, but other numerical designations could be employed instead. The ranking ordering constraint is also imposed in a manner that requires that items having an earlier auction expiration period must receive a higher ranking. For example, an item with an auction closing date of Jan. 1, 2000, must be given a higher ranking than an item with an auction closing date of Jan. 2, 2000. In the event that the first item is not successfully acquired by the user, the present invention automatically designates the next highest ranked bid as the active bid, and this can occur even across items having different auction closing times. In this way, a user can enter a single bid, and yet have such bid carried over multiple auctions until they achieve a successful result. [0120] Upon entering a maximum bid and rank for each selected tee time, the user submits their bids by pressing Submit button 860 , and they are thereafter processed in the manner explained above with reference to FIGS. 1, 2 . [0121] FIG. 9 illustrates a seller inventory input page 900 for sellers to provide information on inventory items 178 for auction, which, in the preferred embodiment, is for golf tee times. Again, the input mechanism is preferably available online through a conventional browser to maximize convenience to sellers. As above, like numerals are used to denote like parameters where appropriate. Thus, a seller inputs new inventory for an auction by first inputting a date for the tee time in field 905 . The seller then specifies in field 906 whether an auction administrator should collect the entire bid amount or only the premium above the standard greens fee at the end of the auction. The seller also specifies a normal greens fee for this date in field 907 (which can be useful for various comparative analyses not relevant to the present invention) and a time interval between tee times in field 908 , which is used to notify winning bidders of the exact winning time at the close of the auction period—in other words, an item might be identified as an 8:00 tee time, but the actual exact time might be offset by some spacing period to accommodate multiple persons within the time slot. [0122] To input information for the auction items (tee times), the seller first specifies a time window in field 930 for the tee times, and the first tee time available within that time window in field 931 for each line item listed. The seller also provides a group size in field 936 , which specifies the number of available spots of that group size within the specified time window in field 935 . The seller also specifies a minimum acceptable bid amount/reserve price 945 and a Buy Now price in field 955 , which represents a price at which the buyer can be guaranteed to purchase a tee time immediately, without having to wait for the end of the auction. Finally, the seller enters the inventory for sale by pressing Submit button 965 . [0123] It should be noted that user interaction screens of FIGS. 6, 7 , 8 and 9 are web pages with interfaces specifically adapted for a golf tee time auction, and are but one expression of a preferred embodiment of the invention. It will be understood that the invention will be tailored and expressed through routine skill in different ways to accommodate different auction environments, and therefore it is not limited to any particular implementation. For example, while an Internet version of the auction input/review screens is described that operates within a browser, these aspects of the invention could also be implemented in hand-held devices or terminals. Furthermore, it is not necessary that the users be remote from each other, and, in fact, they can be at a single centralized location as in the case of a live car auction, for example, where many participants may be at a single location bidding on an item put up for display. Thus, the particulars of the I/O interactions are not material except to the extent that they are sufficient to allow users to engage in the auctioning processes described herein. Furthermore, those skilled in the art will appreciate that the underlying software code associated with such screens for handling and interacting with databases 160 , 165 , 170 , auction items 178 , processing user queries and bid submissions, retrieving and presenting search results, etc. can be implemented in any conventional fashion, and thus is not discussed at length here since it is not material to an understanding of the present invention. [0124] FIG. 10 is a simplified flow chart of the bidding process as seen from a user's viewpoint from interacting with screens 600 , 700 and 800 above. The user can search the available inventory with user item search input screen 600 ( FIG. 6 ) by specifying their particular criteria at step 1010 (for example, available times at a particular course). At step 1020 CAC 100 will search the appropriate databases 155 and present a list of potential items for the user using search results page 700 ( FIG. 7 ). If there is no item acceptable to the user at step 1030 , the user is allowed to specify a new search at 1035 , or to end the query at step 1037 . If the search is continued, new search parameters are entered at step 1040 , and the process is repeated. [0125] In the case where at least one item is found that matches the user's criteria, the search results are tagged at step 1050 . For each of the items presented to the user using bid entry page 800 , he/she can enter bids at 1060 , and rank them at step 1070 . Thus, the unconditional bids and conditional bids are submitted at the same time for any group of items. At 1080 , the user can submit the bids, and, if desired, monitor the auction process at step 1090 using search results page 700 . At step 1095 , the user may receive auction results, either in the form of e-mail messages requesting an increase in a bid, or in the form of a notification of the final auction results. Thereafter the user can take appropriate action such as by increasing an amount of the bid, or by simply letting a next highest bid roll be considered instead by default. [0126] Thus the reader will see that the above system provides a highly advantageous system to simultaneously auction mutually exclusive items. This system allows the user to enter multiple, rank ordered bids that are sequentially processed. This allows the user to effectively bid on a large number of items without the concern that they will receive more than one item. The system has the additional advantages of increasing the average expected winning bid for each item, increasing the probability of sale for each of the items and decreasing the incentive for a user to enter incrementally higher bids at the last moment of the auction (sniping). [0127] It will also be appreciated by those skilled in the art that the above discussion is directed to a preferred embodiment of the present invention, and that the present teachings can be used in a variety of different forms, in a number of different environments, applications, etc. and with various supplementary features. For example, to enhance the experience of successful participants, at least in a golf environment application, it is beneficial to evaluate user provided skill levels to combine and stagger play accordingly. Thus, an ultimate decision for identifying a specific winning tee time for an 8:00 tee slot an auction participant (i.e., whether it is actually 8:10, 8:20, 8:30, etc.) could be based on playability factors particular to the participants, the course, available play spacings, etc. Accordingly, it is intended that all such alterations and modifications be included within the scope and spirit of the invention as defined by the following claims.

Various methods and systems for auctioning mutually exclusive items such as golf tee times, restaurant reservations, concert tickets or hotel reservations are disclosed. Mutually exclusive can refer to items that cannot be possessed simultaneously because of physical limitations or to multiple items that could be simultaneously physically possessed but the bidder would only want possession of, at most, one of the items. An electronic auction method therefore performs the following operations: (1) an ordered processing of ranked bids to compare currently active bids with current winning bids to determine the new winning bids; (2) notifying unsuccessful bidders via e-mail to increase their bids; (3) comparing the new bid amount to all outstanding active and winning bids if the unsuccessful active bid is increased; (4) designating the active bid an inactive bid and designating the next highest ranked bid as the user's current active bid if the unsuccessful bid is not increased in the allotted time; and, (5) continuing the protocol until all bidders either have a winning bid or no remaining active bids. An auction system includes a Central Auction Controller (CAC) that allows sellers to list items for auction and users to enter bids and rank orderings. The CAC maintains a central database comprising a database of user information, a database of items and bids and a database of vendor information. Administration of the system is accomplished via an I/O device and CPU and an optional e-mail processor allows automated messaging to users. This methodology allows users to effectively bid on a large number of mutually exclusive items but receive at most one item at the end of the auction. This method has the favorable effects for the users of: (1) increasing the probability of successfully bidding for at least one item; (2) making the auction process more convenient by greatly reducing the need for actively monitoring the auction; and, (3) decreasing the possibility a user will be out bid at the last moment and receive no item. This method has the favorable effects for the seller of increasing the probability their listed items will sell and increasing the expected average sales price.

BACKGROUND OF THE INVENTION [0001] The present application relates generally to the distribution of fluids, and specifically to methods and systems for distributing such fluids. [0002] There are many uses of industrial fluids. For example, manufacturing industries often use industrial fluids to lubricate manufacturing equipment, as coolant in cutting operation, and the like. Similarly, in the automotive industry, vehicle service centers use a variety of fluids in the repair and/or maintenance of vehicles. [0003] Generally if a user consumes such fluids in any substantial quantity, the user prefers to receive the fluids in bulk form, in order to realize cost savings in supply and delivery costs, reduce container waste, and the like. Merely by way of example, an automotive repair shop might maintain an underground (or aboveground) bulk storage tank for motor oil, and might contract with an oil supplier for delivery of bulk oil to that tank on a periodic or as-needed basis. [0004] The receipt of fluids in bulk, however, presents several problems, for both the fluid supplier and the user of those fluids. For example, the installation and/or maintenance of facilities for storing and/or dispensing bulk fluids generally are relatively expensive, requiring a substantial outlay of initial capital to install the facilities as well as period costs to maintain the facilities. Further, the user generally must purchase the fluid at the time of delivery, even though most of the fluid may not be used for some time, tying up additional capital that could be better used in other ways. In addition, fluid stored in bulk tanks is difficult to use, requiring specialized equipment to transfer a usable quantity of the fluid from the bulk tank to the location in which is the fluid is to be used. For example, many users of bulk fluids use hoses incorporated within hose reels, such as those available from Samoa Industrial, S.A. of Gijon, Spain, to deliver fluids from bulk tanks to the location of use. Such reel systems, however, are often expensive, and they do not allow the use of fluids in locations outside the reach of the hoses. Moreover, such hose reels require bulk tank systems, including pumps, pipes and reels, and therefore normally are used only for fluids consumed in relatively high volumes—other fluids are generally purchased in individualized containers, imposing higher per-unit costs on the supplier and/or user. Additionally, such installed systems are normally considered, for tax purposes, appurtenances to the property on which they are installed, requiring lengthy amortization and other unfavorable tax treatment. Those skilled in the art will appreciate that such classification of these systems also hinders the fluid supplier's ability to lease (or provide other favorable terms towards the user's acquisition of) the systems. [0005] Alternatively, a user may pump a limited quantity of a fluid from a bulk tank into a portable cart, which the user then transports to the use location. Such carts, examples of which are also available from Samoa Industrial, are generally inefficient, however, because they must be refilled periodically, requiring additional trips between the tank location and the use location. Moreover, neither the hose reels nor the mobile carts can mitigate the costs to both the supplier and the user associated with the delivery and/or storage of bulk fluids. [0006] Bulk delivery of fluids also presents other limitations for the fluid supplier. Generally, bulk fluids must be transported in specialized trucks with large tanks, requiring the fluid supplier to operate and maintain a fleet of such trucks, along with the personnel to operate the fleet. An article in the May 2001 issue of Compoundings magazine, written by Thomas F. Glenn and entitled “What Does It ‘Really’ Cost To Deliver A Gallon Of Lubricant?” (the entirety of which is incorporated herein by reference for all purposes), describes many of the costs facing fluid suppliers. This problem is exacerbated for the supplier in the case of small and mid-sized users, who may require fluids in quantities insufficient to justify delivery by tank truck. Such users, moreover, may be situated in remote locations, often requiring a long, expensive trip for the truck to deliver a relatively modest amount of the supplied fluid. [0007] Thus, there is a need for novel systems and methods for delivering and/or dispensing fluids, and particularly industrial fluids. BRIEF SUMMARY OF THE INVENTION [0008] Embodiments of the invention provide novel containers, systems, methods and software products to facilitate efficient packaging, delivery and/or dispensing of fluids, and in particular, industrial fluids. Such industrial fluids can include, without limitation, petroleum-based fluids, automotive fluids, industrial lubricants, cutting fluids, cooling fluids, and the like. In accordance with certain embodiments of the invention, fluids may be delivered in transportable and/or ready-to-dispense containers, eliminating the need for expensive, custom delivery solutions. Advantageously, therefore, such containers may be delivered using general purpose delivery vehicles, allowing delivery to be outsourced to a third party (if desired), and reducing the capital expenditures and operating costs fluid suppliers experience in securing delivery of their supplied fluids. Moreover, receipt of fluids packaged in such containers allows the users of fluids to forego expensive equipment installation and provides a more flexible environment for the use of fluids. [0009] In accordance with certain aspects of the invention, a fluid container may be configured to be coupled to a fluid delivery station, which can be mobile and/or capable of locomotion, allowing the user to position the fluid delivery station in an optimal location for the dispensation of fluids and/or to move the delivery station among various locations, providing flexible dispensing options for the user. In accordance with some embodiments, the fluid station can be configured to communicate with a control terminal, which can serve to authorize the dispensation of fluids and/or account for fluids dispensed. The control terminal, which may be (but need not be) situated at the user's location, can also be configured to communicate with the fluid supplier. In this way, fluid can be accounted for as it is dispensed, if desired. Further, fluid consumption by a machine may thus be monitored, and problems such as leaks, over-consumption, etc. (which may indicate a machine failure) can be monitored by the user and/or supplier. [0010] Merely by way of example, in accordance with some embodiments, the fluid may be owned by the supplier even after delivery, and ownership of the fluid may be transferred to the user only upon dispensation from the fluid container. This may allow the user increased financial flexibility, since the user need not pay for the fluid in bulk. Additionally, the dispensed fluid may be measured and monitored, and the amount of fluid remaining in the container calculated, so that an order for one or more additional container(s) of fluid may be recorded automatically upon reaching a certain threshold amount of fluid dispensed from the container and/or remaining in the container. [0011] One set of embodiments, therefore, provides fluid containers that may be used for the delivery and/or dispensation of fluids. Merely by way of example, an exemplary embodiment provides a fluid container, which may be transportable and which can be used in a relationship between a fluid supplier and a user of fluids. The exemplary fluid container can be used for delivering a fluid from the fluid supplier to the user. The fluid container can be configured to be transported by a general-purpose delivery vehicle, if desired. The fluid container can also be configured to contain therein a fluid that may be dispensed by the user. The fluid may be an industrial fluid, which can include, inter alia, a petroleum-based fluid, a lubricant for a vehicle, a cutting fluid, and/or the like. [0012] In some embodiments, the transportable fluid container further can be configured to be placed in fluid communication with a fluid distribution station, including without limitation those stations described below. Thus, the user may dispense a first amount of fluid from the transportable fluid container using the fluid distribution station, and, in some cases, the first amount of fluid dispensed from the transportable fluid container may be measured and accounted for separately from a second amount of fluid remaining in the transportable fluid container. Optionally, ownership of the first amount of fluid dispensed from the transportable fluid container can be transferred from the fluid supplier to the user, while ownership of the second amount of fluid remaining in the transportable fluid container can remain with the fluid supplier. [0013] In particular embodiments, the fluid container may comprise a fluid displacement mechanism, which can be configured to be coupled to the fluid distribution station, thereby providing fluid communication between the fluid container and the station. The fluid displacement mechanism can be operable to dispense fluid from the fluid container via the fluid distribution station. In other embodiments, the fluid container may be associated with an identifier, which can be configured to identify the container and/or the fluid contained within the container. [0014] Another set of embodiments provides fluid distribution stations, which can be configured to dispense at least one fluid. An exemplary fluid distribution station can comprise a connecting mechanism for providing fluid communication between the fluid distribution station and one or more fluid container(s). The fluid container(s) may be similar to the fluid containers described above and hereinafter. The fluid distribution station may further comprise a fluid displacement mechanism configured to transfer an amount of fluid from one of the container(s) and/or fluid measurement device for measuring the amount of fluid transferred from the container. The fluid measurement device may comprise an impulse flow meter, a scale, etc. [0015] In some cases, the fluid displacement mechanism may operate using a pressurized gas. The fluid distribution station may also feature an attachment mechanism configured to provide fluid communication between an external source of pressurized gas and one or more of the fluid container(s). Alternatively and/or in addition, the fluid distribution station may be further configured to be in fluid communication with an additional container having contained therein a supply of pressurized gas. The fluid distribution station can be operable to provide fluid communication between the additional container and one or more of the fluid container(s), and the fluid displacement mechanism, therefore, can operate using this supply of pressurized gas. [0016] The distribution station may also include a communication system operable to transmit information about the fluid transferred from the fluid container. In some cases, the communication system can comprise a radio frequency (“RF”) antenna. In certain embodiments, the fluid distribution station can further comprise a control system, which can include a processor and/or instructions executable by the processor to receive from the fluid measurement device data about the fluid transferred from the fluid container(s). In other embodiments, the control system can comprise further instructions for transmitting to a control terminal via the communication system data about the fluid transferred from the fluid container(s) and/or instructions for receiving from a control terminal an authorization to dispense an amount of fluid from one or more of the fluid container(s). [0017] A further set of embodiments provides systems for distributing fluids. One such exemplary system can be used in a relationship between a fluid supplier and a user, and the system can comprise one or more fluid container(s), which may be transportable and/or may be similar to the fluid containers described herein. Some systems can also include fluid distribution stations, which likewise can be similar to those stations described herein. In accordance with some embodiments, the fluid distribution station can be configured to dispense an amount of fluid from the fluid container(s) and/or determine/measure the amount of fluid being dispensed from the fluid container(s). The station can be further configured to transmit information about the dispensed fluid. [0018] In some embodiments, the system can further include a computer system in communication with the fluid distribution station. The computer system can be incorporated within the fluid distribution station and/or a control terminal remote from the fluid distribution station. The computer system can comprise a processor and/or instructions executable by the processor to receive the information about the dispensed fluid and/or account for the dispensed fluid. Accounting for the fluid dispensed can comprise, inter alia, any of the accounting procedures described below. [0019] Further embodiments of the invention include computer software products for facilitating the distribution of industrial fluids and/or computers executing such software products. The software may be embodied on a computer readable medium and may include instructions executable by a computer processor to perform any of the methods and/or functions described herein. Merely by way of example, some computer software products can include instructions executable by a processor to receive information about a fluid being dispensed from a fluid distribution station and/or fluid container, including without limitation those described elsewhere herein. The instructions can further be executable to determine the amount of fluid dispensed from the fluid distribution station/container, transmit information about the dispensed fluid and/or account for the dispensed fluid. At least part of the software product may be configured to be executed on a processor incorporated in a fluid distribution station, a control terminal (which can be located at a facility operated by the user) and/or a server (which can be operated by the fluid supplier). [0020] Another set of embodiments includes methods of distributing and/or dispensing fluids, which can be, inter alia, any of the industrial fluids described herein. One exemplary method of distributing an industrial fluid, which can be used in a relationship between a fluid supplier and a user, comprises providing at the user's location a fluid container (which can be transportable). The fluid container can have contained therein an industrial fluid, and/or the fluid container and/or the industrial fluid can be owned by the fluid supplier. In some cases, providing the fluid container can comprise transporting the fluid container to the user's location while the container has contained therein the industrial fluid. [0021] The method can further comprise allowing the user to dispense an amount of industrial fluid from the transportable fluid container and/or, as the amount of industrial fluid is being dispensed from the fluid container, determining the amount of industrial fluid dispensed. The method can also include accounting for the fluid dispensed from the transportable fluid container, which can comprise, inter alia, any of the procedures described herein for accounting for the fluid. Merely by way of example, accounting for the dispensed fluid can comprise transferring from the fluid supplier ownership of the dispensed fluid, transmitting to the fluid supplier information about the dispensed fluid, billing the user for the dispensed fluid, determining an amount of fluid remaining in the fluid container(s) and/or, if the amount of fluid remaining in the container is less than a threshold value, recording an order for additional industrial fluid and/or recording an order for an additional fluid container having contained therein the additional industrial fluid. As another example, accounting for the dispensed fluid can include determining whether a machine using the dispensed fluid is operating properly. [0022] A method in accordance with other embodiments can comprise providing a fluid distribution station at the user's location, and the fluid distribution station can be configured to be coupled with one or more fluid container(s). In some cases, providing the fluid distribution station can comprise leasing the fluid distribution station to the user. In other cases, the fluid distribution station may be mobile and/or may comprise means for locomotion. The method can further comprise providing at least one fluid container having disposed therein a fluid for distribution and/or coupling the fluid container(s) with the fluid distribution station, such that the fluid distribution station and the container(s) are in fluid communication. In some cases, the fluid and/or the container(s) can be owned by the fluid supplier. [0023] In some embodiments, the method can further comprise allowing the user to dispense an amount of fluid from the fluid container(s), e.g., by using the fluid distribution station, and/or, as the fluid is being dispensed, determining with the fluid distribution station the amount of fluid dispensed from the fluid container(s). The method can also include communicating to the fluid supplier information about the fluid dispensed from the fluid container(s) and/or transferring ownership of the dispensed fluid from the fluid supplier. Moreover, the method can include determining an amount of fluid remaining in the fluid container(s) based on the amount of fluid dispensed from the fluid container(s) and/or communicating to the fluid supplier the amount of fluid remaining in the fluid container. [0024] A control terminal may also be provided, and the control terminal can be in communication with the fluid distribution station. The control terminal, therefore, can be configured to received data from the fluid distribution station about the fluid dispensed from the fluid container(s). Thus, communicating to the fluid supplier information about the fluid dispensed from the fluid container can comprise transmitting from the fluid distribution station data about the fluid dispensed from the fluid container, receiving at the control terminal the data about the fluid dispensed from the fluid container, and/or transmitting from the control terminal to the fluid supplier the data about the fluid dispensed from the fluid container. Alternatively and/or in addition, an authorization to dispense fluid from the fluid container may be transmitted from the control terminal. The authorization may specify an amount of fluid to be dispensed, and/or a request for authorization may be transmitted from the fluid distribution station. [0025] In accordance with yet further embodiments of the invention, a method of dispensing an industrial fluid may comprise providing a fluid distribution station, which can be configured to be coupled with one or more fluid containers. The method can further include coupling one or more fluid container(s) (which may be transportable) with the fluid distribution station, such that the station an the fluid container(s) are in fluid communication. The fluid container(s) can have contained therein one or more industrial fluid(s) owned by a fluid supplier. Fluid may be dispensed from the fluid container(s), perhaps by using the fluid distribution station, and/or as the fluid is being dispensed, the amount of fluid dispensed can be determined. Further, information about the fluid dispensed can be transmitted to a computer remote from the fluid distribution station. In some cases, a second container may be coupled with the fluid distribution station and/or pressurized with a gas. The gas may also be dispensed from the second container, and/or the gas may serve as a source of pressure for dispensing the industrial fluid. [0026] The invention has been summarized briefly above. Those skilled in the art may ascertain additional benefits and features attendant to various embodiments of the invention by reference to the Figures, which are described in detail below, and to the remaining disclosure, which describes those Figures in detail. BRIEF DESCRIPTION OF THE DRAWINGS [0027] The figures illustrate one or more exemplary embodiments of the invention, which are described in detail in the remaining portions of the specification. In the figures, like reference numerals are used throughout to refer to similar components. In some instances, a sub-label consisting of a lower case letter is associated with a reference numeral to denote one of multiple similar components. When reference is made to a reference numeral without specification to an existing sub-label, it is intended to refer to all such multiple similar components. [0028] FIG. 1 illustrates a system for distributing and/or dispensing fluids, in accordance with various embodiments of the invention. [0029] FIG. 2 is a generalized schematic illustration of a computer system, which may be used in the distribution and/or dispensation of fluids, in accordance with various embodiments of the invention. [0030] FIG. 3A is a perspective drawing of a fluid distribution station, in accordance with various embodiments of the invention. [0031] FIG. 3B is a generalized schematic drawing illustrating a processor for controlling a fluid distribution station and/or a fluid container, in accordance with embodiments of the invention. [0032] FIG. 4 is a generalized schematic drawing of a system for dispensing fluid from a fluid container, in accordance with various embodiments of the invention. [0033] FIG. 5 is a generalized schematic drawing of a system for providing a pressurized gas to displace fluid from a fluid container, in accordance with various embodiments of the invention. [0034] FIGS. 6A and 6B illustrate the exterior of a transportable fluid container in accordance with embodiments of the invention. [0035] FIG. 7 is a process flow diagram illustrating an exemplary method for dispensing a fluid, in accordance with embodiments of the invention. DETAILED DESCRIPTION OF THE INVENTION [0036] Various detailed embodiments of the present invention are disclosed below; one skilled in the art should understood, however, that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. [0037] Among other things, embodiments of the present invention provide systems and methods for delivering and/or dispensing fluids. Although various embodiments of the invention may be suitable for delivery and/or dispensation of any type of fluid, one skilled in the art will appreciate, based on the disclosure herein, that certain embodiments are particularly appropriate for delivering and/or dispensing (sometimes collectively referred to herein as “distributing”) industrial fluids. As used herein, the term “industrial fluid” can mean any type of fluid that may be delivered for use in bulk form, including without limitation in industrial, manufacturing and/or automotive applications. Merely by way of example, industrial fluids used in automotive applications can include, inter alia, fuels, motor oils (synthetic, petroleum-based), coolants, transmission fluids, power steering fluids, windshield washer fluids, etc. Exemplary fluids used in industrial and/or manufacturing applications can include without limitation machine lubricants, coolants, cutting fluids, machining fluids, solvents, dilutants, cleaning fluids, manufacturing chemicals, reagents, and/or the like. In many (but by no means all) cases, industrial fluids can be petroleum-based. [0038] Turning now to FIG. 1 , some embodiments of the invention provide systems for distributing fluids, and system 100 can be considered exemplary of some such systems. The exemplary system 100 can utilize a network 105 . The network 105 can be any type of network familiar to those skilled in the art that can support data communications using any of a variety of commercially-available protocols, including without limitation TCP/IP, SNA, IPX, AppleTalk, and the like. Merely by way of example, the network 105 can be a local area network (“LAN”), including without limitation an Ethernet network, a Token-Ring network and/or the like; a wide-area network; a virtual network, including without limitation a virtual private network (“VPN”); the Internet; an intranet; an extranet; a telephone network, including without limitation a public switched telephone network (“PSTN”), a wireless telephone network, a private branch exchange (“PBX”) and/or the like; an infra-red network; a wireless network, including without limitation a radio frequency (“RF”) and/or microwave network, such as a network operating under any of the IEEE 802.11 suite of protocols, the Bluetooth™ protocol known in the art, frequency modulation (“FM”) band transmission, shortwave transmission, and/or any other wireless protocol; and/or any combination of these and/or other networks. [0039] In particular embodiments, the network 105 may comprise a PSTN, wherein device communicate with one another via telephone call, sometimes via intermediation by modem. The network 105 may provide continuous, periodic and/or as-needed communication between various devices. It should be noted as well that, although for ease of illustration, only one unified network is illustrated, a plurality of networks (which may be in communication with one another) may be utilized to provide communications between different devices. [0040] The system 100 can also include a variety of devices, which can be in communication with one another, either directly (e.g., via serial connect, parallel connection, etc.) and/or via the network 105 . For example, the system 100 illustrated by FIG. 1 includes a server computer 110 and a control terminal 115 , which may be in communication via the network 105 . In the illustrated embodiment, the server 110 is be situated at a fluid provider's location, and the control terminal 115 is located at the user's location. The physical locations of these devices, however, are discretionary and therefore may vary in other embodiments. For instance, the control terminal 115 may be located at the fluid supplier's location and/or the server 110 may be located at the user's location. In some embodiments, the functionality (described in detail below) of both the server 110 and the control terminal 115 may be incorporated into a single computer. [0041] The server, as described in more detail below, can allow the fluid supplier to monitor and/or account for fluid dispensed using the system 100 , and can have any hardware and/or software configuration commonly used by those skilled in the art. Merely by way of example, a server 110 may incorporate one or more of the components described in detail with respect to FIG. 3 , infra. The server 110 can be programmed with any suitable operating system, including without limitation any of those discussed below, as well as any commercially-available server operating systems, including, merely by way of example, OS/390™, OS/400™, VMS™, UNIX™ (including any of its varieties and/or similar variants), and the like. The server 110 can also run a any server applications necessary to provide communication with the control terminal 115 and/or other devices; such applications can include including HTTP servers, FTP servers, CGI servers, database servers, Java servers, and the like. In particular, the server 110 can be encoded with any necessary communications and/or database software to allow the server 110 to receive information from, and/or transmit instructions/information to, the control terminal 115 . [0042] Merely by way of example, the server 110 can include one or more applications accessible by a the control terminal 115 (or another device, such as a client computer, not illustrated on FIG. 1 but familiar to those skilled in the art, a telephone, a pager, a wireless device, and the like). Merely by way of example, the server 110 can be comprise or more general purpose computers capable of executing programs or scripts in response to requests from and/or interaction with client devices, including without limitation web applications. Such web applications can be implemented as one or more scripts or programs written in any programming language, including merely by way of example, C, C++, Java™, COBOL, or any scripting language, such as Perl, Python, or TCL, or any combination thereof. Such web applications can be used to access information about fluid distribution, authorize distribution, record orders for additional fluid(s), configure the server 110 , and the like. [0043] As mentioned above, the server 110 can also include database server software, including without limitation packages commercially available from Oracle™, Microsoft™, Sybase™, IBM™ and the like, which can process requests from database clients running on a client device (which may be the control terminal 115 ). The database software can be used to manage a database of fluid users, fluids delivered and/or dispensed, fluid inventory, delivery schedules and/or the like. The database may be incorporated within a storage device 120 , which can comprise one or more hard drives, databases, etc. FIG. 1 depicts the storage device 120 as located proximate to the server 110 , as this location generally provides for efficient operation of the system 100 , but the location of the storage device 120 is discretionary: it can reside on a storage medium local to (and/or resident in) one or more of the server 110 , the control terminal and/or other devices. Alternatively, the storage device 120 can be remote from any or all of these device, so long as it is in communication (e.g., via the network 105 ) with one or more of these. In some embodiments, the storage device 120 can comprise a storage-area network (“SAN”) familiar to those skilled in the art. [0044] In some implementations, the server 110 may include a telephone interface, which can allow the server to interact with an ordinary (POTS) telephone. The telephone interface, which may be implemented in software and/or hardware embodied in the server 110 and/or in a separate device in communication with the server, can provide integrated voice response (“IVR”) features familiar to those skilled in the art. The telephone interface also can be configured to interpret dual tone multi-frequency (“DTMF”) tones as data input. Thus, in accordance with embodiments of the invention, the telephone interface 115 can allow for a user and/or administrator to interact with a server 110 via voice and/or DTMF commands. Thus, for example, a user may request a delivery of fluid by calling the server 110 and submitting voice and/or DTMF commands. Alternatively, the user may place a request by using a web browser communicating with the server and/or by communicating a request through the control terminal 115 . In still other embodiments, as described in detail below, the control terminal 115 may be configured to record an order automatically for additional fluid by contacting the server 110 . [0045] The control terminal 115 can be in communication with a fluid distribution station 125 . The communication between the control terminal 115 and the fluid distribution station 120 may be direct and/or via the network 105 (and/or a private subset of the network 105 , such as a LAN and/or VPN). In particular embodiments, the communication between the control terminal 115 and the fluid distribution station 120 (and/or fluid container 130 ) may be wireless, including without limitation via any of the wireless communication methods discussed above. Merely by way of example, the communication between the control terminal and the fluid distribution station/fluid container can comprise a spread-spectrum RF transmission (utilizing any necessary hardware known in the art, such as repeaters, etc. to facilitate the transmission). In other embodiments, the communication may be via a solid medium, such as a serial link, an Ethernet link, an IEEE 1394 link, etc. [0046] The fluid distribution station 120 , which is described in detail with respect to FIGS. 3-5 , can be coupled with one or more fluid containers 130 , each of which contains therein one or more industrial fluids to be dispensed by the user. (As used herein, the term “coupled with” implies any connection between the two elements coupled with one another, whether indirect or direct. In particular, where two elements are coupled with each other for purposes of providing fluid communication between those elements, the term “coupled with” should be interpreted as connoting any connection that provides the required fluid communication, regardless of the means of coupling the elements with one another.) As described in detail below, the fluid container(s) 130 can be configured to allow dispensation of the fluid directly from the container 130 , allowing the user to forego bulk storage of the fluid and eliminating the need to install or otherwise use additional dispensing equipment. The fluid container(s) 130 also can, in some embodiments, be configured to be easily transportable by a general purpose transportation vehicle, such as a utility truck. In this way, for instance, a fluid supplier may deliver (or contract to have delivered) to the user any necessary fluids in a container 130 already configured to dispense the fluid, providing enhanced efficiency to both the user and the fluid supplier. [0047] In addition, as described in detail below, the modular format of the fluid containers 130 can allow for accounting of the fluid on an as-used basis, if desired. Many previous fluid distribution methods, whereby fluids are delivered in bulk to a tank at the user location, fail to allow for this flexibility in accounting. Thus, the containers 130 featured in some embodiments of the invention can allow a fluid user to eliminate the need for an inventory of fluids, thereby reducing costs for the user. As another advantage over other fluid distribution systems, the containers 130 may be reusable, reducing both waste products and costs for both the fluid supplier and the user. Merely by way of example, when a new fluid container is delivered, an empty container may be placed on the delivery vehicle for return to the fluid supplier, where it may be refilled for future use. [0048] Moreover, the fluid containers 130 may be used for other purposes as well. Merely by way of example, an otherwise empty fluid container may be charged with a pressurized gas (by the user and/or the fluid supplier) and thereafter used to dispense the gas and/or provide a source of pressurized gas for dispensation of other fluids. In addition, the containers 130 may (but need not be) configured to allow the user to fill the container with a fluid of the user's choice, allowing the containers 130 to be used for many purposes. [0049] The fluid containers 130 may be provided in any appropriate size. Generally, the containers 130 will range in volume from about one pint to about one hundred gallons in capacity, and more particularly, from about twenty gallons to about fifty gallons in capacity, although containers of other sizes certainly may be used in accordance with various embodiments of the invention. In a certain set of embodiments, the containers 130 are standardized to hold between about two quarts and about fifty gallons of fluid, and more particularly between about one gallon and about twenty gallons of fluid. Often, the containers 130 are generally cylindrical in shape, although other configurations may be used as well. [0050] The fluid containers 130 may be configured to dispense fluid without assistance from any other equipment. Alternatively, a fluid distribution station 120 may be used to facilitate the distribution of fluids. The fluid distribution station 120 , as described in detail below, can include facilities for measuring the fluid as it is dispensed, controlling the dispensation of fluid (e.g., for security and/or safety purposes), and/or communication data about the fluid and/or its dispensation to the control terminal 115 . In an alternative embodiment, the functionality ascribed herein to the fluid distribution station 120 may be incorporated within one or more of the fluid containers 130 . [0051] The control terminal 115 , therefore, can be used to authorize dispensation of fluid from the fluid distribution station 125 and/or the fluid container(s) 130 . The authorization may be in response to a request from the fluid distribution station, as described in more detail below. The control terminal 115 may also be used to calculate and/or make a record (locally and/or at the server 110 ) of the amount and/or nature of the fluid dispensed, the amount of fluid remaining in a fluid container 130 , and/or any other information relating to the dispensing of fluid using the station 120 . As described above, the control terminal 115 may also be in communication with one or more servers (e.g., 110 ), and the control terminal may be configured to transmit information to and/or receive information from the server(s) 110 . Detailed examples of such transmissions are discussed below with respect to FIG. 6 . In some embodiments, a plurality of control terminals 115 , distribution stations 120 (and/or fluid containers 130 ), and/or servers 110 may be in communication. Thus, for example, a single control terminal could communicate with several distribution stations at a user facility and/or a single server could communicate with several control terminals at one or more user facilities. Alternatively, a user facility could employ a network of control terminals, each communicating with one or more distribution stations. In further embodiments, a distribution station could incorporate the functionality of a control terminal and/or could communicate directly with a server. [0052] In some embodiments, a control terminal can comprise specialized hardware adapted to communicate with a fluid distribution station 120 and/or a server 110 . In fact, the control terminal can serve merely as a communication intermediary between these components. In other embodiments, however, the control terminal can comprise one or more general purpose personal computers (e.g., 115 ) (including, merely by way of example, personal computers and/or laptop computers running any appropriate flavor of Microsoft Corp.'s Windows™ and/or Apple Corp.'s Macintosh™ operating systems) and/or workstation computers running any of a variety of commercially-available UNIX™ or UNIX-like operating systems. The control terminal 115 may incorporate one or more of the components described with respect to FIG. 2 , infra. [0053] The system 100 may also include one or more additional client devices, which, depending on their capabilities, can operate to receive information about the system (e.g., fluid levels, fluids dispensed, accounting information, system status information, etc.) and/or to transmit information (e.g., requests for authorization to dispense a fluid, orders for more fluid, status inquiries, etc.) to the server 110 , control terminal 115 and/or fluid distribution system 120 These client devices, which can be located at the supplier location, user location and/or elsewhere, and which can be operated by the supplier, user and/or a third party) can comprise any electronic device capable of communicating with the system 100 (using voice communications, data communications, and/or the like). Exemplary devices include, but are not limited to, personal computers, thin-client computers, POTS telephones and/or wireless telephones (e.g., 145 ), Internet-enabled mobile telephones, handheld computers and/or personal digital assistant (e.g., 135 ), pagers (e.g., 140 ). These client devices, again depending on their capabilities, can also have any of a variety of applications, including one or more database client and/or server applications, and/or web browser applications. Although the exemplary system 100 is shown with three client devices, any number of each of the illustrated client devices can be supported, and those skilled in the art will appreciate that the illustrated devices, while exemplary, are not exhaustive of the types of client devices that could be supported by embodiments of the invention. [0054] FIG. 2 provides a generalized schematic illustration of a processing device 200 that may be used in accordance with the embodiments of the invention, including, for instance, the exemplary system 100 described above. Merely by way of example, one or more of the components described as part of the processing device 200 may be incorporated into the server 110 , control terminal 115 , fluid distribution station 120 and/or other client devices supported by various embodiments of the invention. [0055] FIG. 2 provides a schematic illustration of one embodiment of a system 200 that can perform the methods of the invention and/or the functions of a client device, server computer and/or communication processing system, as described herein. This figure broadly illustrates how individual system elements may be implemented in a relatively separated or relatively more integrated manner. The device 200 is shown comprising hardware elements that can be coupled electrically via a bus 255 , including a processor 205 ; an input device 210 , which can include without limitation a mouse, a keyboard, a numeric keypad, a tablet and/or the like; an output device 215 , which can include without limitation a speaker, a display device, a printer and/or the like; a storage device 220 , which can include without limitation a disk drive, an optical storage device, solid-state storage device such as a random access memory (“RAM”) and/or a read-only memory (“ROM”), which can be programmable, flash-updateable and/or the like; and a computer-readable storage media reader 225 . The computer-readable storage media reader 225 can further be connected to a computer-readable storage medium 230 , together (and, optionally, in combination with storage device(s) 220 ) comprehensively representing remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing computer-readable information. Such storage media (sometimes in conjunction with one or more processors, memory devices, instructions and/or the like) can serve as a means to perform many of the storage functions described elsewhere herein. [0056] The processing device 200 can further comprise a communications system 235 ; which can include without limitation a modem, a network card (wireless or wired), an infra-red communication device, an RF and/or wireless transceiver and/or antenna, and/or the like. The communications system 235 may permit data to be exchanged with the network 105 and/or any other computer/device described above with respect to the system 100 . The processing device 200 can also include a memory 240 , which can include a RAM or ROM device, as described above. [0057] The computer system 200 also can incorporate software and/or firmware instructions, which can be executed by one or more of the hardware components to accomplish specific functions in accordance with embodiments of the invention. In this way, for instance, a processor (e.g., the illustrated processor 205 , perhaps in conjunction with the illustrated processing acceleration unit 235 ), when executing such instructions, can serve as a means to perform many of the functions described elsewhere herein. These instructions can include operating systems and application programs, as described in detail above and/or as known in the art. Such instructions are illustrated in FIG. 2 as located within a working memory 240 , including an operating system 245 and other code 250 (e.g., an application program), which are described above and/or designed to implement methods of the invention. It will be apparent to those skilled in the art that substantial variations may be made in accordance with specific requirements. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, software (including portable software, such as applets), or both. Further, connection to other computing devices such as network input/output devices may be employed. [0058] FIG. 3A provides a detailed perspective drawing illustrating a fluid distribution station 120 in accordance with various embodiments of the invention. The station 120 generally comprises a body 305 capable of supporting one or more fluid containers (which may include fluid containers 130 described above). The body 305 can be constructed of any suitable material, including without limitation, steel, aluminum, titanium, plastic (including suitable thermoplastics), and/or the like. The body 305 can include one or more means for facilitating the dispensation of fluid from the containers 130 , including, merely by way of example, one or more hose reels 310 . Any of several varieties of commercially-available hose reels may be used, including, for instance, those hose reels available from Cox Reels, of Tempe, Ariz., USA. Other means for facilitating the dispensation of fluid may be used as well, including simple hoses (which can be constructed of any suitable material, including rubber, nylon, and the like). In some cases, it may be preferable for the hoses to be resistant to corrosion from the types of fluids likely to be dispensed by the cart 120 . In other embodiments, other devices may be used to facilitate dispensation of fluid, including taps, spigots and the like. Such devices may rely exclusively on gravity for their operation, or they may be assisted by one or more pumps, pressurized gas, etc. [0059] In some embodiments, such devices for dispensing the fluid may be connected to and/or incorporated in the fluid containers 130 , and/or the devices may be mounted on, incorporated in and/or attached to the fluid distribution system 120 itself. Merely by way of example, the hose reels 310 in the example illustrated here are coupled to a mounting frame 315 , which may be attached to and/or incorporated with the cart body 305 . Each of the dispensing devices may include any necessary additional apparatus (not illustrated in FIG. 3A but described in detail below) to facilitate dispensing, including without limitation, handles (which can incorporate triggering devices to control the flow of dispensed fluid), check valves (e.g., to prevent backflow of the fluid), metering devices, and the like. [0060] In some embodiments, the mounting frame 315 may be removably attached to the body 305 (e.g., with bolts and/or other similar fasteners, tongue-and-groove fittings and/or the like), allowing the frame 315 and/or the hose reels 310 to be easily removed and/or replaced. In other embodiments, the frame 315 may be attached relatively permanently (e.g., welded, etc.) to and/or formed together with the body 305 . In such embodiments, the dispensing devices (e.g., hose reels 310 ) may be relatively removably attached to the frame 315 . In some cases, each of a plurality of dispensing devices may be in contact with each of a plurality of containers, for instance to prevent cross-contamination of different fluids being dispensed and/or to allow the dispensation of multiple fluids simultaneously. Merely by way of example, the fluid distribution station 120 of FIG. 3A includes a plurality of connection hoses 320 , each of which can provide fluid communication between a container 130 (and/or another fluid source, such as a source of pressurized gas) and a hose reel 315 . In other cases, a single dispensing device may be in fluid communication with a plurality of containers (or vice-versa) using manifold and/or other fluid routing systems familiar to those skilled in the art. [0061] In accordance with certain embodiments, the fluid distribution station 120 may include one or more means for providing pressure to the station 120 and/or the fluid containers 130 . Merely by way of example, the station 120 can include one or more gas input hose reels 325 , which can be configured to accept a supply of pressurized gas, such as air, oxygen, nitrogen and/or the like. (In some cases, it may be desirable that the pressurized gas comprises an inert substance, such as argon, etc., to prevent reaction with the fluid being dispensed.) Alternatively (or in addition), one or more of the fluid containers 130 may be filled with a pressurized gas (from a hose reel 320 and/or another source) and used as a source of pressurized gas, allowing the fluid distribution station 120 to be used without a connection to a separate source of pressurized gas. In other embodiments, other pressurizing methods may be used; for example, a pump (which can either be a liquid pump and/or a gas pump) may be integrated with and/or attached to the station 120 and/or one or more containers to provide direct pressure on the fluids being dispensed and/or to provide an independent source of pneumatic pressure for the fluid containers 130 . Merely by way of example, the station 120 and/or any of the containers 130 could include (and/or be in fluid communication with) a manual pump, an electric and/or combustion-driven pump, and/or the like. [0062] As noted above, in accordance with many embodiments, a fluid distribution station and/or a fluid container may include control electronics, which can include one or more processors and/or any of the other components described with respect to FIG. 2 , to facilitate, monitor and/or control the dispensing of fluid from the station and/or container. Merely by way of example, the fluid dispensing station 120 of FIG. 3A features a housing 330 which can be (but need not be) accessible to the user of the station 120 via a hatch, door, etc. (not shown on FIG. 3A ). The housing 330 can enclose such control electronics (not illustrated in FIG. 3A but described in detail with respect to FIG. 3B , infra, and referred to generally as a “processor” in this discussion), which can include one or more specialized processors (e.g., a processor embedded incorporating and/or coupled with a memory having instructions to control the processor) and/or a general-purpose computer having specialized software. In either case, the processor can have instructions for operating various functions of the fluid distribution station 120 and/or fluid container(s) 130 . [0063] The processor may have an input interface, such as a keyboard, touch pad, joystick, trackball, etc. to allow a user to input data, control station 120 and/or fluid container 130 functions, request authorization to dispense, etc. The processor may also have an output interface, such as a screen (which can be a CRT, an LCD and/or the like) a LED/LCD readout, indicator light(s), and the like, to convey to a user information about functioning of the station 120 and/or fluid containers 130 . Merely by way of example, the illustrated fluid distribution station 120 includes a keypad 335 and a display screen 340 as input and output interfaces, respectively, to the processor. The location of the input and/or output interfaces are discretionary. For example, in the illustrated station 120 , the keypad 335 and display screen 340 are affixed to (and/or incorporated in) the housing 330 . In other embodiments, the input and/or output devices may be located elsewhere, such as attached to the frame 315 , to allow for easier viewing and/or input of data. In still other embodiments, there may be a plurality of input and/or output interfaces on the station 120 , to allow for expeditious data input and/or review from a variety of positions respective to the station. [0064] As described in more detail below, the processor can provide communication and/or control with various of the systems implemented by the distribution station 120 , in accordance with certain embodiments of the invention. In addition, the processor may include (or be in communication with) one or more data communication interfaces, which can serve as a means for communicating with a control terminal and/or a server. Some exemplary communication devices are described above. Thus, for instance, the station 120 may include a wireless transmitter, receiver and/or antenna 345 , which can communicate by wireless and/or RF communication with a control terminal and/or server similarly equipped. Alternatively (and/or in addition), the station 120 may comprise a wired communication interface (e.g., an Ethernet port, a serial port, etc.) to support a wired connection. [0065] As noted above, in some embodiments, the fluid distribution station may be mobile. Thus, the station 120 may be mounted on one or more mobility devices, which can include, inter alia, casters, wheels, tires, treads, and the like, and which may be of uniform or different sizes. Those skilled in the art will appreciate that different types of mobility devices can be used to accommodate different operating environments and/or surfaces. In some cases, the mobility devices can be adapted to correspond to tracks, rails, etc., allowing the station 120 to move only along specified paths. In other cases, the mobility devices can allow for relatively free movement of the station 120 , allowing the station 120 to be maneuvered into any desired position. Merely by way of example, the station 120 illustrated in FIG. 3A includes a plurality of wheels 350 , which can allow the station relatively free mobility along any relatively smooth surface. If desired, the fluid distribution station 120 may have one or more controls (e.g., a tiller 365 , which is commonly available and known in the art, a steering wheel, a joystick, a keypad, a touchscreen, a mouse, a trackball, etc.) and/or handles to allow for the manipulation of the station 120 . The controls (e.g., the tiller 365 ) may be coupled, electronically and/or mechanically (e.g., via linkages known in the art) to one or more of the mobility devices, which may be steerable, allowing the tiller 365 to be used as a steering apparatus. Optionally, the tiller 365 and/or other means, such as friction brakes, etc., can be used to lock the mobility devices, preventing undesired movement of the station 120 . [0066] In addition, the distribution station 120 may be capable of powered movement, to mitigate and/or eliminate any physical effort from a user in moving the station 120 . Thus, the station 120 may include one or more means for locomotion (also referred to herein as “locomotive means”), which can comprise, inter alia, one or more electric motors, combustion-driven motors, and/or the like, along with, in some cases, any necessary control apparatus, including without limitation those discussed above. Merely by way of example, the illustrated station 120 includes an electric motor 355 (illustrated as enclosed within a housing), which is in communication with one or more of the wheels 350 , using a standard drive train known in the art. The choice of motors is discretionary. In some embodiments, the motor(s) collectively can produce sufficient power to move the station 120 at the desired velocity. Those skilled in the art will appreciate that there are many commercially-available powered cards and/or cart-powering systems, including without limitation the systems available from the Hilgendorf Cart Division of CSF, Inc., Stouton, Wis., USA and/or the systems described in U.S. Pat. No. 5,522,471 issued Jun. 4, 1996 to Hilgendorf and/or U.S. Pat. No. 3,308,974 issued Mar. 14, 1967 to Rosenbaum, of which the entire disclosures of each are incorporated herein by reference for all purposes. One skilled in the art will appreciate, based on the disclosure herein, that such powered carts and/or powering systems may be modified as appropriate and used to perform certain functions of a distribution station in accordance with various embodiments of the invention. [0067] In some embodiments, the tiller 365 (and/or other controls) can be in communication with the locomotive means (directly and/or via control electronics, as described below), allowing the use of the tiller 365 to regulate both the direction and the speed of the station 120 . Merely by way of example, in particular embodiments, the station 120 comprises three wheels, two disposed near one end and toward either side of the station 120 , with the third wheel disposed centrally and toward the other end. The third wheel may be steerable, and the tiller 365 may be in communication with the third wheel, to provide steering control to the user. The third will may also be coupled (via a linkage and/or a direct-axle drive) to the locomotive means, such that the locomotive means drives the third wheel, with the tiller providing both velocity control (via the locomotive means and/or a brake) and steering control (via the positioning of the third wheel). [0068] The fluid distribution station 120 may also provide a fuel source for the locomotive means and/or the control electronics. If the locomotive means comprises an electric motor, a suitable fuel source can be one or more batteries (e.g., battery 360 ) having a suitable output current. In such cases, the battery 360 can also be used to power the control electronics (and/or any other components incorporated in and/or attached to the station 120 and/or fluid tanks 130 requiring electric power), and/or one or more additional batteries can be provided for this purpose. If the locomotive means comprises a combustion engine, the fuel source for the engine can be a tank containing the appropriate fuel for the engine, and the engine may drive a generator and/or alternator for providing electric power to the control electronics and/or other devices. Alternatively, a separate generator and/or batteries may be provided for this purpose. [0069] In accordance with some embodiments, the station 120 can include wiring to provide electrical communication between the processor and various other components. FIG. 3B provides a schematic diagram illustrating a processor 370 coupled to several such components, in accordance with certain embodiments of the invention. As illustrated in FIG. 3B , the processor 370 can be in communication with one or more flow metering and/or control devices 375 (discussed in detail infra), which themselves can be in fluid communication with the station 120 , fluid containers 130 , and or any attached fluid distribution devices, such as hose reels. In a particular embodiment, a separate flow meter and/or flow control device can measure and/or regulate the flow of fluid out of each container. In this way, the processor 370 can control and/or receive data regarding the flow of fluid through such devices. The processor 370 may also be in communication with one or more pressure regulators and/or gauges (also described in detail, infra), allowing the processor to control and/or receive data regarding the gas pressure transmitted to (and/or within) the fluid containers 130 . In some cases, a single regulator/gauge may be used to measure/regulate pressure (e.g., the regulator/gauge can be attached to a main supply line from a pressure source, while in other cases, each container 130 (or supply line thereto) may incorporate and/or be in communication with its own regulator/gauge. If a pump 385 is used to facilitate the distribution of fluid, the processor 370 may also be in communication with the pump 385 , and therefore the processor can be used to monitor and/or control the operation of the pump. [0070] In order to receive instructions (e.g., for controlling a flow control device, etc.), the processor may be in communication with an input interface, such as the keypad 335 (and/or any other input interface, including those discussed above). Similarly, to allow the user to monitor the operation of various components of the station 120 (and/or the processor's control over those components), the processor can be in communication with an output interface, such as the display 340 illustrated here. To provide data communication between the station 120 and a control terminal and/or server, the processor may be in communication with a communication device, which can include, for instance an wireless transmitter, receiver and/or antenna 345 , as well as various other communication devices discussed above. [0071] In accordance with embodiments where the fluid distribution station is configured for powered movement, the processor 370 may be in communication with any locomotive means (including, for instance an electric motor 355 ) and/or any control device 365 used to operate the locomotive means. In this fashion, the processor may (but need not) assist in the control of the station's motion (for instance, regulating and/or translating input from the control device 365 ) and/or monitor the motion of the station 120 (e.g., by calculating and/or providing information about the velocity of the station 120 ). In accordance with other embodiments, however, the control device may be in direct communication with the locomotive means, bypassing the processor. [0072] Similarly, those skilled in the art will appreciate that the functions ascribed to the processor 370 may be divided among a plurality of processors (e.g., one processor relating to dispensing operations, another related to locomotive operations, and yet another covering communication with a control terminal and/or server). Each of the plurality of processors may be (but need not be) in communication one with another. In other embodiments, some of the operations may not utilize a processor. [0073] Certain embodiments of the invention may feature an “attachment mechanism” and/or a “connecting mechanism,” which can be any device (or system of devices) that function to provide fluid communication between two components, including for example, a fluid container and a fluid distribution station (in the case of a connecting mechanism) and/or a pressure source and a distribution station/fluid container (in the case of an attachment mechanism). Merely by way of example, a connecting/attachment mechanism can comprise a delivery tube, a quick-connect fitting, a threaded fitting, etc. Thus, one or more of components of a dispensing system and pressure supply system, examples of which are illustrated schematically on FIGS. 4 and 5 , respectively, may function as an connecting mechanisms and/or attachment mechanisms. [0074] The exemplary dispensing system 400 of FIG. 4 may be implemented in conjunction with (and/or as a part of) a fluid distribution station and/or fluid container, such as those described above. The exemplary dispensing system 400 includes a fluid container 130 , which may comprise a delivery tube 405 incorporating (and/or in fluid communication with) a check valve 410 , which can prevent fluid backflow, as will be appreciated by those skilled in the art. Disposed at (or near) one end of the delivery tube 405 , there may be a contaminant-prevention device (such as a filter, strainer, etc. commonly used in the art), which can serve to prevent any particulate or other contaminants in the stored fluid from entering the delivery tube 405 . [0075] The other end of the delivery tube may extend through one surface of the fluid container 130 , where it may terminate in any of several well-known hydraulic valves and/or connectors, including for example, a quick-connect valve 420 (of which the whole and/or a part can serve as a connecting mechanism). The valve 420 can provide fluid communication between the delivery tube 405 and a fluid supply hose 425 , which can further be in fluid communication with a fluid dispensing device, such as a hose reel 310 . A flow measuring device 430 , which can comprise an impulse meter and/or any similar device known in the art, may be incorporated and/or coupled to the supply hose 425 in such a way that the flow measuring device 430 is operable to measure the rate and/or volume of fluid flowing out of the container 130 and/or through the supply hose 425 . In addition, the fluid dispensing system 400 may incorporate a flow control device 435 , such as a solenoid valve, manual valve, pressure sensitive valve, etc. to regulate or otherwise control the flow of fluid from the container 130 . The hose reel 310 (and/or a hose incorporated with the hose reel 310 ) may be in fluid communication with an additional dispensing device 440 , which can facilitate the dispensing of fluid using the system 400 . Examples of dispensing devices can include oil control guns, such as those commercially available from, among others, Samoa Industrial, S.A.; Graco, Inc., Minneapolis, Minn., USA; Alemite Corp., Charlotte, N.C., USA; Balcrank Products, Inc., Weaverville, N.C., USA; and Lincoln Industrial Corp., St. Louis, Mo., USA. In some cases, the dispensing device 440 can include additional flow control apparatus, allowing a user to control directly the flow of fluid through the dispensing device 440 . [0076] The fluid dispensing system 400 can also include a pressure source 445 , the operation of which is described in further detail with respect to FIG. 5 and which can include a supply line for supplying a pressurized gas, a pump, and/or the like. In operation, therefore, the pressure source 445 can apply a pressure to the fluid in the container 130 , forcing fluid through the delivery tube 405 into the supply hose 425 , where the flow of the fluid can be measured by the flow measuring device 430 and/or controlled by the flow control device 435 . If allowed by the flow control device 435 , the fluid can flow to the hose reel 310 and/or the dispensing device 440 , where it may be dispensed by the user. The fluid container 130 may also be coupled with a gas supply line 445 , which can provide a supply of pressurized gas to facilitate the dispensing of fluid from the container 130 . [0077] FIG. 5 illustrates an example system 500 for supplying pressurized gas in accordance with embodiments of the invention. The system 500 includes a fitting 505 that may be coupled to a source of compressed gas, and which may function as an attachment mechanism. In some embodiments, the source of the compressed gas may be external to the fluid distribution station (e.g., a commercially available, high-volume compressor installed at the user's facility, etc.), while in other cases, the source of the compressed gas can be incorporated in (and/or attached to) the station itself (e.g., a fluid container having stored therein pressurized gas, a portable pump and/or compressor, etc.). The fitting 505 can be a commercially-available pneumatic quick-connect fitting and/or any other suitable fitting that can provide communication between the system 500 and a source of pressurized gas. The system 500 can further include a source hose reel 510 in communication with the fitting 505 , so that the fitting 505 may be extended away from the system (and, by implication, from the station and/or containers with which the system 500 is used), allowing for the use of a fixed source of pressurized gas while still allowing positional freedom and/or mobility for the station/containers. The source hose reel 510 can provide pressurized gas to a distribution line 515 , which may incorporate (and/or be coupled to) any known measuring and/or regulating device (collectively depicted as a regulator/gauge 520 ), which can include, merely by way of example, a gauge (which can be analog and/or digital, and/or which can be in communication with control electronics, as described above), a regulator (which likewise can be in communication with control electronics), a filter, and/or the like. Using such devices, system-wide pressure can be controlled and/or monitored (manually and/or via the control electronics). [0078] The distribution line 515 can comprise any suitable material, including several varieties of commercially-available air hoses, metallic (e.g., copper, steel, etc.) tubing, and/or the like, and can be in communication with one or more fluid containers 130 , for instance as described with respect to FIG. 4 . Merely by way of example, the distribution line may be coupled with a plurality of T-adaptors, each of which can be coupled (using an extension hose, if needed, and/or any necessary attachment fittings) with one or more fluid containers 130 . The distribution line 515 can also include means for interrupting the supply of pressurized gas to the containers, for instance to allow for a quick method of ceasing all fluid distribution options. Merely by way of example, the exemplary system uses a solenoid valve 525 , which may be in communication with control electronics. Other means could include a manual valve, a pressure-sensitive valve, and/or the like. The supply line 515 may also provide a supply of pressurized gas to one or more gas distribution hose reels 530 via an auxiliary supply line 535 , which may be coupled with the distribution line 515 using any suitable means. The gas distribution hose reels therefore can provide a supply of pressurized gas for any suitable use (such as inflation of tires, cleaning, operation of pneumatic tools, and/or the like), and may include and/or be coupled to any fittings suitable for such uses. [0079] In some embodiments, the layout of the distribution line 515 and the auxiliary line 535 may be arranged to subject to regulation and/or monitoring by the gauge/regulator 420 and/or the solenoid valve 525 . In other embodiments (such as that illustrated by FIG. 5 ), the auxiliary line 525 may be coupled to the distribution line in such a way as to bypass these devices. In further embodiments, the auxiliary line 535 may include similar devices for monitoring, filtering and/or controlling the flow of pressurized gas to the gas distribution hose reels 530 . [0080] Taken together, the systems described with respect to FIGS. 4 and 5 (and/or any of the components thereof) can represent one example of a “fluid displacement” mechanism, which, for purposes of this document, should be thought of as any mechanism/system for displacing fluid from a fluid container, allowing the dispensation of that fluid in a desired location. Other examples of fluid displacement mechanisms, described in detail above, can feature pumps, vacuum systems, etc., and/or any necessary hoses, tubing, fittings, etc. [0081] FIGS. 6A and 6B depict the exterior of an exemplary fluid container 130 . In accordance with some embodiments of the invention, a top portion 605 of the container 130 may describe several openings, each of which may be used for various purposes, and each of which may include to appropriate valves, fittings and/or the like. In particular, each of the openings may include valves (which may be self-sealing) in order to allow the interior portion of the container 130 to be pressurized to facilitate the dispensation of fluid therefrom. In some embodiments, the openings may be circular (and/or any other suitable shape) andy may vary in size (according to application) from one-eight inch to two inches, and in particular from one-quarter inch to one-half inch. Merely by way of example, the top portion 605 may feature a first opening 610 , through which a fluid delivery tube 405 may extend from the exterior of the container 130 into the interior, to allow the transmission of fluid from the container. The opening 610 may be configured to form a tight fit around the delivery tube 405 to prevent the loss of pressure from the container 130 . Alternatively, the opening 610 may comprise a fitting (e.g., a hydraulic quick connect, a threaded fitting, etc.) coupled to the delivery tube 425 (which can extend therefrom into the interior of the container 130 ), such that the delivery tube 425 does not extend to the exterior of the container, and the fitting may further be coupled to a fluid supply hose 425 . Thus, the fitting may function as a connecting mechanism in accordance with certain embodiments of the invention. [0082] The top portion 605 may also comprise a second opening 615 , which also can be coupled to a gas supply line 445 (e.g., by a pneumatic quick-connect valve, a threaded fitting, etc.), to allow for the pressurization of the container 130 . A third opening 620 can feature a fitting to allow the attachment of a gauge, regulator, etc (as described above), to allow for the monitoring and/or control of the pressure inside the container 130 . A fourth opening 625 can be configured to have disposed therein a pressure-relief valve commonly known in the art, which can be configured to open at a certain pressure (which may be configurable by the user), to prevent overpressure in the container 130 , reducing the risk of equipment failure. A fifth opening 630 can be configured to accept a cap (e.g., by including threading that corresponds to a threaded portion of the cap, etc.), which, when removed, can provide access to the interior of the container 130 , to allow inspection, refilling, etc. In accordance with particular embodiments, the fifth opening can be between about one-and-one-half inches and about two-and-one-half inches, which can allow for quick refilling of the container 130 . [0083] In various embodiments, the openings on the top portion 605 may be arranged differently, and/or openings may be added and/or omitted. Likewise, the openings (or others) may be positioned on different portions of the container. Those skilled in the art will appreciate that the configuration of the container and/or openings is discretionary, and that the configuration illustrated on FIGS. 6A and 6B is merely exemplary. [0084] Some embodiments of the invention provide methods of distributing fluids. One exemplary method 700 in accordance with various embodiments is illustrated by FIG. 7 . The method can include providing a distribution station and/or control terminal to a user (block 705 ). In some cases, providing this equipment can comprise selling the equipment to the user. In other cases, a fluid supplier might provide the equipment in other ways, to mitigate the up-front capital outlay required of the user. Merely by way of example, if the user agrees to a relatively long-term contract for purchasing fluids (and/or other goods/services) from the supplier, the supplier could agree to offer favorable financing terms for the equipment, or even provide the equipment for a reduced price (or for free, either permanently or for the duration of the contract term). In addition, the supplier could lease the equipment to the user, again mitigating up-front costs to the user and providing an incentive for the user to contract with that supplier. (Alternatively, if the user may provide a general computer, and providing the control terminal can comprise providing (e.g., selling, licensing, giving) the necessary control software and/or communication equipment to the user for use with the user's computer.). [0085] The method can further comprise filling one or more transportable fluid containers (block 710 ). Because the containers can be configured to be transportable when full, filling the container usually (but not necessarily) occurs at a factory, refinery, depot, etc., where the fluids are stored in large quantities by the supplier and/or a third party. Alternatively, in some embodiments, the container may be filled at another location, such as at the user's location, either by the user, the fluid supplier and/or by a third party. In this way, embodiments of the invention can allow the user and/or supplier great flexibility in determining how the containers are used and/or filled. (If desired, containers may be configured to be openable for filling only by the supplier, allowing the supplier to control how the containers are used/filled). [0086] The fluid and/or containers (either filled or unfilled) may be transported to the user's location (block 715 ). Advantageously, because the containers can be modular and/or transportable, transportation of the fluid in containers may be accomplished by any general purpose vehicle (such as a dry-goods delivery vehicle), obviating the need for the traditional tank truck for the delivery of the fluids. Thus, if desired, transporting the containers can comprise contracting with a third party (such as a delivery services, freight shipper, etc.) to transport the containers to the user's location. In any case, transport of the fluid (within the containers) is likely to be significantly more efficient and/or less expensive than delivery by traditional methods. In some cases, however, the supplier and/or user may choose to have fluids transported more traditionally (e.g., in a tank truck), and the containers may be filled from that truck (and/or a larger storage tank) located at the user's facility. [0087] Notably, however, in accordance with certain embodiments, transport of a fluid and/or container to the user need not include transferring ownership of the fluid from the supplier (and/or a third party) to the user. As explained in more detail below, the supplier (and/or a third party) may retain ownership of the fluid until some of the fluid is dispensed from the container, at which point the dispensed fluid may be accounted for, while the fluid remaining in the container can remain the property of the supplier and/or the third party. (Of course, in alternative embodiments, ownership of the fluid may be transferred upon delivery, in the traditional fashion). [0088] One or more containers may then be coupled to a fluid distribution station (block 720 ). The containers may be filled or empty, and coupling a container to the fluid distribution system can comprise placing the container on, in or near the station, and/or providing fluid communication between the container and the station. Additionally, coupling a container to a station can comprise coupling the container to a source of pressurized gas (as described above), to provide a fluid displacement mechanism for the fluid in the container. Coupling the container to the station can further comprise inputting (via an input interface at the station, via a control terminal, and/or via a server) data about the container and/or the fluid contained therein. Such data can include instructions about whether authorization is required to dispense the fluid, the volume of fluid in the container when first coupled to the station, the nature of the fluid in the container, and/or the like. [0089] In some cases, each container might have an associated identifier, which can serve to identify the container and/or the fluid it contains. Such an identifier can be displayed on the container, printed on a manifest, included in a bar code on the container and/or manifest (such that the user and/or supplier can use commonly-available bar code scanners to input information about the container), stored in an Radio Frequency Identification (RFID) chip (such that a receiver in communication with the distribution station, control terminal and/or server can receive information about the container electronically, and/or the like). In some cases, the identifier (or a portion thereof) might be a code that indicates the type and/or quantity of fluid in the container when delivered, such that the identifier (or portion thereof) is common to each container having that type of fluid and/or is modifiable depending on the type and/or amount of fluid currently stored in the container. In other cases, the identifier (or a portion thereof) might be an identifier that uniquely identifies the container, such that the identifier can be used to determine the type and/or amount of fluid in the container when transported (e.g., by querying the supplier's server using the identifier as a key). Such identifiers can provide for efficient inventory control for both the supplier and/or the user. Alternatively, data about the container and/or fluid in the container may be input manually by the supplier and/or user into the server, control terminal and/or distribution station. [0090] In some embodiments, the distribution station/fluid container can include a menu-driven system for selecting fluids to be dispensed. If desired, information about available fluids may be transmitted to and/or stored at the distribution station, and/or the user may be presented with a menu of fluids available for dispensing. The menu can be updated automatically and/or manually as needed, and the menu can, if desired, display the currently-available amount of each fluid. Optionally, a certain amount of one or more fluids may be reserved (for instance, for a future, high-priority project and/or to prevent the complete consumption of fluids before additional fluids can be ordered), so that the menu indicates that less fluid is available than is actually present. If the user has sufficient authority, this reservation may be overridden. [0091] In cases in which authorization is required before fluid may be dispensed from the container, the method can comprise authorizing the dispensation of fluid (block 625 ). In some cases, the distribution station may request authorization. For example, a user may input (e.g., using an input interface) at the station a request to dispense a given volume from a certain container coupled with the station. Alternatively, the user may simply attempt to dispense from a given container. In either case, the station may respond to the user's actions by sending an authorization request to a control terminal and/or server and/or waiting to dispense fluid until an authorization has been received from the control terminal and/or server. In other cases, a control terminal and/or server may authorize dispensation without a request from a station. For instance, a user (and/or the fluid supplier) may input a command at the control terminal (and/or server) to authorize a fluid distribution station to dispense a particular fluid without requiring a request for authorization from the station. In some cases, a user may be required to “log in” to the fluid distribution station/fluid container by entering an identifier and/or password before the dispensing of any fluid is allowed. This login information can be verified by the station, control terminal, server, etc. as desired. (In some cases, the process of logging in can automatically activate procedures preliminary to dispensing activities, such as pressurization of fluid containers, etc.) [0092] In either case, the authorization may be a general authorization (e.g., authorizing the station to dispense any amount of fluid up to the amount remaining in a given container and/or authorizing the station to dispense from any container coupled to the station) or a more limited authorization (authorizing the station to dispense only a specified amount of fluid and/or to dispense from only a specified container). For instance, a general authorization scheme may be implemented for security purposes, such that a user must “log in” by inputting a security code at the station, at which point the station will be generally authorized to dispense fluid (either for a specified period of time, until a specified period of inactivity has lapsed, until the user has logged out, etc.). Alternatively and/or in addition, a limited authorization scheme may be implemented (e.g., with respect to relatively expensive fluids, etc.), whereby each time a user wants to dispense an amount of a certain fluid, the user must input the type and/or amount of fluid desired, and the control terminal and/or server then can authorize the dispensation of only the requested type/amount of fluid. (It should be noted that, in some embodiments, limited and/or general authorization schemes may be implemented by the distribution station, without requiring any communication with a control terminal and/or a server.) In some cases, the system can verify that the desired amount of fluid is present in the fluid container(s) before authorizing dispensation of those fluids and/or can display for the user a message (e.g., at the distribution station and/or control terminal) that sufficient fluid is/is not present. If insufficient fluid is present, the user may be logged out of the station automatically and/or the station may be shut down [0093] At this point, fluid may be dispensed from the station and/or a fluid container (block 730 ). Dispensing the fluid can comprise operating the station/container as described above to allow fluid to be dispensed as desired. In some cases, the type, amount and/or rate of fluid dispensed can be controlled manually (e.g., by operating a fluid dispensing gun until the desired amount of fluid has been dispensed). In other cases, these values may be controlled by the control electronics, in conjunction with flow metering and/or control devices, either before and/or during dispensing Thus, the user may enter, using an input interface, the desired amount, type, flow rate, etc. of the fluid to be dispensed, and the station may control the dispensing electronically, such that the user need only to position the output hose (or other dispensing device) in the proper position and instruct the station to begin dispensing the fluid. (One skilled in the art will note from the disclosure herein that this process can be combined with the authorization process, if desired). Alternatively, the fluid may be dispensed until the user indicates (perhaps via the control electronics) that dispensing should cease. In addition, the user may enter an identifier associated with the fluid being dispensed (e.g., a project code, customer identifier, etc.), which can facilitate the user's accounting for and/or billing of the fluid used. Optionally, there may be a facility on a distribution station/fluid container to allow for relatively immediate cessation of dispensing activities, allowing for an emergency stop, etc. This facility can include closing a valve on a supply pressure line, a fluid distribution line, etc. [0094] As the fluid is being dispensed (and/or thereafter), the amount of fluid dispensed may be determined (block 735 ), by direct measurement, calculation, etc. Merely by way of example, as discussed above, a station and/or container may include an impulse flow meter that functions to measure the fluid as it is dispensed. Alternatively and/or in addition, the station may comprise means for weighing the container before and/or after dispensing (e.g., a scale upon which the container sits, etc.), and the amount dispensed can be calculated (by mass, and/or if the specific gravity of the fluid is known, by volume). In some cases, the distribution station may include software (and/or hardware, firmware, etc.) that can track/display for the user a list of dispensing activity, which can include such information as the amount of each fluid dispensed, an associated identifier (project code, etc.) for each amount of fluid dispensed, the name (or other identifier) of the user dispensing each amount of fluid, etc. [0095] Information then may be transmitted by the station and/or container (block 740 ). The information may transmitted to the control station and/or the server, and the information can include, inter alia, data about the type and/or quantity of fluid dispensed from and/or remaining in a container, information about the date and/or time of dispensing, any identifier associated with the dispensed fluid, and/or the like. Transmitting the information may comprise any suitable transmission method, including without limitation those discussed above. [0096] The transmitted information may be received by a control station (block 745 ) and/or transmitted by the control station to the fluid supplier (and/or a server operated by the fluid supplier (block 750 ). In some cases, the information transmitted by the station/container may simply be forwarded by the control terminal to the supplier. (Alternatively, as noted above, the station/container may be configured to transmit information directly to the supplier.) In other cases, information may be stored, modified and/or consolidated before transmission to the supplier. Merely by way of example, information received by the control terminal but not germane to the suppler (e.g., project/client information, time/date of dispensing, information about fluids not supplied by that supplier) may not need to be transmitted to the supplier. As another example, the control terminal may be configured to transmit information to the supplier only periodically and/or when supplies are low (as discussed below). [0097] Optionally, the fluid dispensed may be accounted for (block 755 ). In some cases, accounting for the fluid dispensed can take place at the control terminal, the supplier (e.g., the supplier's server), the fluid distribution station/fluid container, and/or some combination thereof. In many cases, the software (and/or firmware) on one or more of these system components may include instructions for accounting automatically (and/or with human intervention) for the fluid dispensed. Accounting for the fluid dispensed can include many functions. Merely by way of example, accounting for the fluid dispensed can comprise determining the fluid remaining in a container from which fluid was dispensed (block 760 ). For instance, if the amount of fluid in the container prior to dispensation is known, the determined amount dispensed can be subtracted from this known value to determine the amount of fluid remaining. Alternatively, the amount remaining may be determined by weighing a container after dispensation is finished. [0098] Accounting for the fluid dispensed can further include transferring ownership of the fluid dispensed (block 765 ). As noted above, one of the benefits of certain embodiments of the invention is that fluid may be delivered to the user without requiring ownership of the fluid to be transferred until the fluid actually is dispensed. Thus, once a quantity of fluid has been dispensed, ownership of that quantity can be transferred to the user (and/or to a customer of the user, in cases for instance, in which the fluid is provided to a customer of the user, such as in automotive applications). Transferring ownership can (but need not) involve communication between the user (e.g., the station, control terminal, etc.) and the supplier (e.g., the server) at—or shortly after—the time of the transfer. Alternatively, the transfer can be recorded in one location (e.g., at the station, control terminal, etc.), and a reconciliation transaction can be performed periodically (e.g., monthly, etc.) and/or at the time all of the fluid in the container has been dispensed. [0099] In conjunction with (or in lieu of) the transfer of ownership, accounting for the fluid dispensed can comprise billing the user for the fluid dispensed (block 770 ). In some cases, billing the user can comprise invoicing the user electronically and/or on paper. In other cases, billing the user can comprise an electronic transaction (which can be automatic), such as a credit card charge, electronic funds transfer, etc. Thus, in particular embodiments, once a quantity of fluid has been dispensed, ownership of the fluid can be transferred (e.g., in the accounting records of the supplier and/or user), and funds may be transferred from a bank account of the user to a bank account of the supplier, all in a relatively short period of time (e.g., within a day) if desired, and all without human interaction, if desired. Thus, embodiments of the invention can provide for efficient and/or automated accounting of fluid dispensed, reducing both transaction costs and funds “float” by the user and/or the supplier. [0100] Accounting for the fluid dispensed can further include recording an order for additional fluid (e.g., one or more additional containers of fluid). As described above, in accordance with certain embodiments of the invention, the amount of fluid remaining in a given container can be determined. In cases, therefore, where the distribution of fluid from a container leaves remaining in the container a quantity of fluid falling below a certain threshold (e.g., twenty-five percent of the original amount of fluid in the container, etc.), embodiments of the invention can be configured to record an order for additional fluid of that type, either automatically or via human interaction. Once an additional order has been recorded, additional containers may be provided by the supplier (block 780 ), for instance in the manner discussed above. [0101] Merely by way of example, if a user takes delivery of a container having contained therein twenty-five gallons of motor oil and subsequently dispenses twenty gallons of that oil (in one or more dispensing activities), the distribution station used to dispense the oil can measure the oil being dispensed and transfer that information to a control terminal. When the container was delivered, the control terminal may have been was updated (as discussed above) to reflect that the container contained the twenty-five gallons of oil. Thus, when oil is dispensed, the distribution station can transmit to the control terminal the amount of oil dispensed (and/or the container from which it was dispensed), and the control terminal (and/or the station) can determine the amount of oil remaining. At the point that it is determined that less than 5 gallons remain, the control terminal can automatically place an order for additional container(s) from the supplier (e.g., by transmitting the order to the supplier's server). Upon receiving the order, the supplier can arrange for the transport of the ordered container(s) to the user. Those skilled in the art will recognize, additionally, that this process can be adapted to cover situations in which multiple containers of a given fluid are used, such that an order is placed when the user has only a threshold quantity of fluid (and/or containers) remaining overall. [0102] Some embodiments of the invention can be used to determine whether a machine, which uses fluids dispensed by a distribution station and/or fluid container, is operating properly, for instance by comparing the amount of fluid dispensed to that machine with an anticipated amount of fluid. (This process can be thought of as another way of accounting for the fluid dispensed). Merely by way of example, if a particular machine normally uses one quart of lubricant (or any other fluid) over a particular period, software running on a distribution station, fluid container, control terminal and/or server can be configured to track the amount of lubricant (or other fluid) dispensed to that machine over time. For instance, before and/or after dispensing fluid in service of the machine, a distribution station can be configured to allow a user to enter an identifier, project code, etc. associated with the machine to be serviced, and the type/amount of fluid dispensed in relation to that identifier can be recorded and/or tracked. The software can also be configured with a nominal amount of fluid that the machine should receive, such that, if more fluid is dispensed (in a single dispensation and/of in multiple dispensations over time) than the machine should need based on its nominal usage characteristics, the software can notify the user, supplier, etc. that the machine is using more fluid than it should need, which can indicate a machine malfunction, fluid leakage, etc. [0103] As noted above, in some embodiments, a fluid distribution station can be mobile. Therefore, the method 700 can include moving the fluid distribution station (block 785 ), under either external power (e.g., by pushing the station, towing the station, etc.), and/or by using the station's own capacity for powered movement. Once the station has been positioned in its new location, fluid may be dispensed (block 690 ) in the manner indicated above. [0104] As described herein, various embodiments of the invention provide inventive methods and systems for distributing industrial fluids. The description above identifies certain exemplary embodiments for implementing the invention, but those skilled in the art will recognize that many modifications and variations are possible within the scope of the invention. Merely by way of example, although the described embodiments relate to the distribution of industrial fluids, the methods and systems of the invention could be used to facilitate the distribution of virtually any type of fluid. The invention, therefore, is defined only by the claims set forth below.

Embodiments of the invention provide novel containers, systems, methods and software products to facilitate efficient delivery, packaging and/or dispensing of fluids, and in particular, industrial fluids. Such industrial fluids can include, without limitation, petroleum-based fluids, automotive fluids, industrial lubricants, cutting fluids, cooling fluids, and the like. In accordance with certain embodiments of the invention, fluids may be delivered in transportable and/or ready-to-dispense containers, eliminating the need for expensive, custom delivery solutions. Advantageously, therefore, such containers may be delivered using general purpose delivery vehicles, allowing delivery to be outsourced to a third party (if desired), and reducing the capital expenditures and operating costs fluid suppliers experience in securing delivery of their supplied fluids. Moreover, receipt of fluids packaged in such containers allows the users of fluids to forego expensive equipment installation and provides a more flexible environment for the use of fluids.

FIELD OF THE INVENTION The invention relates to a surfactant composition, suitable for enhanced oil recovery and to a method for enhancing oil recovery. BACKGROUND OF THE INVENTION It is well known in the art of oil production that only a portion of the oil present in subterranean oil reservoirs can be recovered by direct methods, also called primary recovery techniques. A portion of the oil which is not recoverable by primary recovery techniques, can be recovered by secondary recovery techniques. The latter techniques include the use of a displacement fluid e.g. water, which is injected into the oil reservoir or into the vicinity of the reservoir. If after application of the secondary recovery techniques an appreciable amount of oil is still retained in the reservoir, it is still possible to recover a part of that oil from that reservoir. This oil, in the form of immobile, capillary-trapped droplets, can be mobilized by injection of suitable surfactant solutions; these interact with the oil to form a micro-emulsion that reduces the capillary trapping forces to a very low level. The process is called surfactant flooding. Once mobilized, the oil forms a growing bank that leaves almost no oil behind in the flooded part of the reservoir. Since the oil bank precedes the surfactant bank it is not necessary to inject surfactant continuously throughout the flood. So when a certain volume of surfactant solution has been injected, it may be followed by a cheaper fluid, such as viscous water; and later water alone. The injection of the surfactant, viscous water and water involves the displacement of oil to the production well. The micro-emulsion on its turn is displaced in the direction of the production well by the viscous water. Consequently a number of moving zones and banks is developing in the oil reservoir and as long as the micro-emulsion is intact, oil can be recovered. Surfactants are soaps or soap-like chemicals. Their molecules consist of a hydrophilic part, attracted to water, and a lipophilic part, attracted to oil. Because of this amphiphilic nature, even at small concentrations, they can greatly reduce the interfacial tension between oil and water and form micro-emulsions. It is a problem to recover the oil from deeper reservoirs, since at ever increasing depths the temperature becomes higher and the micro-emulsion breaks down in oil and water, whereby the oil is again trapped in the pores. The micro-emulsions formed by oil, surfactant and water are thus not stable enough to withstand the higher temperatures. It is an object of the invention to find surfactant compositions which are able to form micro-emulsions which are stable at high temperatures as well as at low temperatures and which over a broad temperature range are in equilibrium with their environment and do not deteriorate. SUMMARY OF THE INVENTION The present invention therefore relates to a surfactant composition, suitable for enhanced oil recovery, which comprises: a) a dialkylated benzenesulfonate of the chemical formula ##STR1## wherein M is an alkali metal and R 1 and R 2 are the same or different C 2 -C 20 alkyl groups, and b) a polyalkoxyphenylethersulfonate of the chemical formula ##STR2## wherein M is an alkali metal, R is a C 9 -C 22 -alkyl group and R 3 is a C 1 -C 4 -alkylene group, and n is an integer from 1 to 20, the weight ratio of a:b being in the range of from 60:40 to 10:90. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a phase diagram of a composition according to the invention. FIG. 2 shows the production performance of the waterflood carried out in the example. FIG. 3 shows the production performance of the surfactant flood carried out in the example. DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred compostions are those wherein M is sodium and wherein R 1 and R 2 independently are C 6 -C 14 -alkyl groups. In a more preferred composition according to the invention R is a C 10 -C 18 -alkyl group, R 3 is an ethylene group and n is an integer of from 1 to 5 and the dialkylated benzene sulfonate predominantly contains the two alkyl groups situated in the para position to each other. In a preferred surfactant composition according to the invention, the weight ratio of the dialkylated benzenesulfonate and polyalkoxy phenylethersulfonate lies between 50:50 and 15:85, preferably between 40:60 and 20:80. The surfactant composition may comprise a thickener, e.g. a polysaccharide. The invention further relates to a method of enhancing recovery of oil from a subterranean oil-containing reservoir, which method comprises injecting into the reservoir an aqueous solution of the surfactant composition, displacing said aqueous solution within said subterranean reservoir, and recovering oil from the reservoir. This procedure can be applied after the water-flooding or already in an early stage of the water-flooding, the latter called the surfactant enhanced water-flooding. The surfactant composition according to the invention has an excellent solubility in cold seawater (20° C.) as well as in seawater at reservoir conditions (95° C.). When oil is present, a type III phase behavior or middle phase is generated which is highly active, thus a low interfacial tension between oil and micro-emulsion water exists. The surfactant composition according to the invention is not sensitive to fluctuations in temperature and salinity. In FIG. 1 is disclosed a phase diagram of a composition according to the invention, given on the right leg of the triangle. On its basis is given the volume percentage (gram surfactant per 100 ml water), while the oil/water ratio is 1. Temperature measurements are all at 95° C. As water seawater is taken. The hatched part of the phase diagram includes the compositions which form a micro-emulsion in equilibrium with both water and oil; consequently in the hatched part a 3-phase system exists. Outside the hatched part a one-phase or two-phase system exists. On the top of the triangle is given 100% weight of C 8 -C 10 -dialkylated sodium benzene sulfonate (DABS), while below on the right is given 100% weight of the C 12 -C 15 -alcoholethoxy sodium benzene sulphonate (containing 5 ethoxy groups per molecule), abbreviated DEBS 25-5. The hatched area of the phase diagram coincides with a single phase area in a phase diagram of seawater/DABS and DEBS 25-5, without oil, at 95° C. as well as at 20° C. The formulations can be injected at 20° C. The invention will now be described further by means of the following example which is illustrative and is not intended to be construed as limiting the scope of the claimed invention. EXAMPLE A surfactant composition according to the invention was tested on its oil production performance in an outcrop sandstone (Bentheim core) at 95° C. The composition comprised the same surfactants as disclosed above in relation with FIG. 1, namely C 8 -C 10 -dialkylated sodium benzene sulfonate (DABS) and C 12 -C 15 -alcohol ethoxy sodium benzene sulfonate (DEBS 25-5) in a concentration of 12.76 g/l and 20.83 g/l respectively. The properties of the Bentheim core were as follows. ______________________________________Length 31.0 cmArea 24.0 cm.sup.2Porosity 20.7%Pore volume 154.0 mlPermeability 1300 mD(arcy)K.sub.ocw 440 mDK.sub.wor 80 mDS.sub.cw 29%S.sub.or 43%______________________________________ The Bentheim core was firstly saturated with seawater, brought to connate water saturation by injecting North Sea crude oil and was followed by a seawater drive. The result of this flood is found in FIG. 2. The cumulative recovery is 39% of the oil initially in place (OIIP). OIIP was 70.8% of PV. For the subsequent surfactant drive, the core was resaturated with crude oil until the connate water saturation was restored. The surfactant composition was injected (total volume 1.75 PV (pore volume)). The result of the surfactant flood is given in FIG. 3. Water breakthrough occurred after 0.39 PV injection, compared with 0.24 PV for the water drive. The subsequent oil bank was produced with an oil cut of 43% and lasted until 1.0 PV total injection. Thereafter clean oil continued to be produced at an average oil cut of 22% during 0.3 PV. An oil-containing micro-emulsion was produced over a period of about 0.4 PV. If oil present in the micro-emulsion was included, the oil recovery reached 100% at 1.4 PV. ______________________________________DATA OF THE VERTICALSURFACTANT FLOOD EXPERIMENT______________________________________WATERFLOODMoveable pore volume (PV) 0.28Water breakthrough (PV) 0.24Oil production at breakthrough (% OIIP) 32Ultimate waterflood recovery (% OIIP) 39S.sub.or (%) 43SURFACTANT FLOODWater breakthrough (PV) 0.39Cum. clean oil production at: 1.0 PV 91(% OIIP) 1.2 PV 97 1.4 PV 100Cum. total oil production at: 1.0 PV 91(% OIIP) 1.2 PV 98 1.4 PV 100______________________________________

A surfactant composition, suitable for enhanced oil recovery comprising in a 60:40 to 10/90 weight ratio a) (o,m)- and/or (o,p)-dialkylbenzene alkali sulfonate and b) polyalkoxyphenyl ether alkali sulfonate.

CROSS REFERENCE TO RELATED APPLICATIONS [0001] None. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] None. LATIN NAME OF THE GENUS AND SPECIES [0003] Ilex×attenuate VARIETAL DENOMINATION [0004] Holly tree which I have named ‘IABOF’. BACKGROUND OF THE INVENTION [0005] The present invention relates to a new and distinct variety of a holly tree ( Ilex×attenuata ), which I have named ‘IABOF’. Discovery: [0007] I discovered my new tree in the summer of 2002 growing in a production field in Belleview, Fla. among a group of cultivated East Palatka holly trees. These trees were grown from 3 gallon liners purchased in the spring of 2001 from a nursery in Florida. In the summer of 2002, these liners were stepped up into larger containers and relocated to a production field. It was here that I discovered the claimed cultivar ‘IABOF.’ Evaluation of this tree continued in this field until it was relocated to an observation area at the University of Georgia, Department of Horticulture Coastal Plain Experiment Station in Tifton, Ga. in 2006. Propagation: [0009] ‘IABOF’ was asexually propagated by the method of vegetative cutting in the summer of 2003 in Belleville, Fla. using four inch long cuttings quick dipped in 2500 Indole-3-butyric acid and 1250 1 -naphthaleneacetic acid without wounding. This propagation from semi-hardwood cuttings in a peat-perlite media took approximately 10 weeks to complete. Resulting progeny has proven the characteristics of my new variety to be genetically stable. Furthermore, these observations have confirmed that my new variety represents a new and improved variety of holly tree as particularly evidenced by a shorter internode length which develops a more compact, dense canopy, an increased caliper to height ratio, and reduced berry weight load. Uniqueness: [0011] ‘IABOF’ was discovered in a block of seedling East Palatka holly trees purchased by a nursery from a supplier of liners in Florida. I claim that the genetic characteristics of this tree are the result of naturally occurring cross-pollination. Due to the nature of the liner purchase, the exact source of the mutation is not known. These improved characteristics distinguish my new trees from other typical East Palatka holly trees. At the time this tree was selected, I observed the ‘IABOF’ holly tree as a darker green, compact growing holly tree having a heavy caliper, reduced fruiting weight load, and tight internode spacing. The remaining trees in this block were typical of the species with irregular structure, branches drooping from berry weight, and signs of Sphaeropsis knot susceptibility. I claim that my ‘IABOF’ exhibits improved structural and aesthetic qualities in comparison to traditional East Palatka holly trees. Use: [0013] ‘IABOF’ was observed for a period of several years and is believed to be particularly useful for street tree planting and in large areas such as, but not limited to, golf courses, commercial sites and parks. ‘IABOF’ will also benefit growers who will profit from a consistent growing tree having a compact form and reduced weight load damage resulting from berry production. SUMMARY OF THE INVENTION [0000] Background: [0015] An East Palatka holly tree, which was discovered as a hybrid in East Palatka, Fla. in the 1920's, is typically pyramidal-shaped in youth and develops an upright oval canopy at maturity. The East Palatka holly tree is native to central Florida. It thrives well in the heat and humidity of the southeastern United States. East Palatka holly trees prefer moist, well-drained soils in these areas, but adapts readily to harsh conditions such as poor drainage, compacted soils, and drought. My new cultivar differs from the species in that it is more compact in height and width, heavier in caliper to height ratio, has shorter internode length and is less susceptible to branch damage due to reduced weight of berries. I expect my new variety ‘IABOF’ to perform as well as the species. Industry Representation: [0017] A cultivated East Palatka holly tree is represented in the industry by materials reproduced by vegetative cuttings from multiple sources. This accounts for a degree of variability in growth rate and habit both in the landscape industry and nursery industry. East Palatka holly trees are widely used in the coastal southeastern United States as an evergreen screen and specimen accent tree. At the time of this submittal, there is no cultivar selection of East Palatka holly tree that I am aware of in the nursery industry. The dark foliage color, reduced berry load, compact pyramidal form and increased caliper make my selection unique. DESCRIPTION OF THE DRAWINGS [0018] The accompanying photographs depict the color and foliage of my new variety East Palatka holly tree as nearly as is reasonably possible to make the same in a color illustration of this character. [0019] FIG. 1 , taken at the University of Georgia, Department of Horticulture Coastal Plain Experiment Station in Tifton, Ga. in 2006, shows the transplanted parent tree at 5 years old, 6.5 feet high, 3.0 feet wide and 2.0 inches in caliper. This photo depicts pyramidal habit with dense branching; [0020] FIG. 2 , taken at the University of Georgia, Department of Horticulture Coastal Plain Experiment Station in Tifton, Ga. in Late summer of 2006, shows the foliage and fruit of the ‘IABOF’ parent tree; [0021] FIG. 3 shows the lower leaf surface of my new variety of holly tree; and [0022] FIG. 4 shows the trunk of my new variety of holly tree. DETAILED DESCRIPTION [0000] Botanical description of the plant: The following is a detailed description of the ‘IABOF’ holly tree with color terminology in accordance with The Royal Horticulture Society (R.H.S.) color chart except where the context indicates a term having its plain and ordinary meaning. My new tree has not been observed under all growing conditions and variations may occur as a result of different growing conditions. All progeny of my new variety, insofar as have been observed, have remained genetically stable in all characteristics described hereinafter. Other than as set out hereinafter, as of this time, no other characteristics have been observed by the inventor are different from that of common East Palatka holly trees. Parentage.— Seedling of East Palatka holly trees grown from container liner purchased in 2001 from a nursery in Florida. Locality where grown and observed.— ‘IABOF’ holly trees are currently in production at a nursery in Belleview, Marion County, Fla. This area of Marion County has a sandy loam soil type with rainfall that varies between 30 inches and 60 inches annually. This particular area is located in USDA Hardiness Zone 9. Size and growth rate.— The original tree, aged 5 years measured 2.0 inches in caliper at 6.0 inches above the ground. The height of 6.5 feet and spread of 3.0 feet provides a 2.17 height to width ratio. Prior to my ‘IABOF’ holly tree being transplanted to the observation area, the average growth rate was 1.25 feet in height per year. Foliage.— Alternate, simple, ovate-rounded. The leaf margin is entire with a terminal spine, cuspidate tip and cuneate base. Entire dimension: 1.25 inches wide by 2.5 inches long. Upper surface is smooth, waxy with medium green like (RHS 137C). The underside is smooth, waxy and yellow green like (RHS144B). The midrib vein color is yellow green like (RHS144C). The internode length is 0.33 inches. Petiole.— ⅜ inch long with channeled texture on upper surface and orange red like (RHS31C). Stem.— 1 year wood is yellow green like (RHS145B) and has pubescence. Flowers.— Early to mid May without fragrance. Size is ¼ inch wide and 1/10 inch high with 4 oblong petals that have rounded tips that are green white like (RHS157D) fading to grayed-orange like (RHS 1 66D). Buds.— Flower buds are ovate, 1/12 inch long and wide and angled at 30-45 degrees and upright color that is green like (RHS 138B). Fruit.— Occurs in tight clusters that are ⅕ inch to ¼ inch diameter and are glossy red like (RHS43A). Fruit appears in late November to mid December. Trunk.— Smooth, gray, becoming gray-brown like (RHS201 B). At time of submittal, the trunk diameter was 2.0 inches measured 6.0 inches above the ground. Branching.— Slightly ascending to nearly horizontal at the base, emerging at 80-90 degrees from the trunk. Upper branches are more ascending, emerging at 30 degrees or more from the trunk. Color is gray (RHS 195B), becoming gray-brown with age. Shape.— Broad pyramidal with dense branching and dominant central leader. Root system.— Fibrous. Vigor.— In production, the progeny have averaged 1.25 feet of vertical new growth per year. The root development from time of softwood cuttings to a finished rooted 3.5 inch pot is five to seven weeks. Disease.— Less susceptible to Sphaeropsis. Pests.— Susceptible to spittlebug.

A holly tree ( Ilex attenuata ) named ‘IABOF’ having a compact, dense canopy, an increased caliper to height ratio, reduced berry weight load and also capable of being reproduced reliably from vegetative cuttings.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a position measurement apparatus, an imaging apparatus, and an exposure apparatus, which can manufacture a device having a micro pattern, such as an a semiconductor chip (e.g., an integrated circuit (IC) or a large scale integration (LSI)), a liquid crystal panel, a charge coupled device (CCD), a thin-film magnetic head, and a micro machine. [0003] 2. Description of the Related Art [0004] A conventional reduced projection exposure apparatus (stepper), capable of manufacturing semiconductor devices, requires a high-accurate technique for capturing an image of a mark formed on a wafer or a reticle and detecting a position of the mark based on a signal waveform obtained from the captured image. [0005] A conventional method for capturing a mark image is described below. FIG. 8 illustrates a conventional exposure apparatus usable in the manufacturing of semiconductor devices. In FIG. 8 , “R” represents a reticle (i.e., an original plate for exposure use), “W” represents a wafer (i.e., a substrate to be exposed), and “WM” represents a wafer mark (i.e., a mark to be observed). A projection optical system 1 has an optical axis parallel to a z-axis of the xyz-coordinate system. A mark imaging optical system S includes an alignment illumination unit 2 , a beam splitter 3 , two imaging optical systems 4 and 5 , and an imaging unit 6 . Furthermore, the conventional exposure apparatus includes an analog/digital (A/D) conversion circuit 7 , an integrating circuit 8 , an image processing circuit 9 , a stage driving unit 10 , a movable stage 11 causing a three-dimensional motion, and a stage position measurement unit 12 (e.g., an interferometer). [0006] The conventional exposure apparatus captures an image of the wafer mark WM according to the following procedure. First, the stage driving unit 10 moves the stage 11 to a position where the stage position measurement unit 12 can observe the mark WM on the stage 11 . Next, the alignment illumination unit 2 emits exposure light (luminous flux) that reaches the wafer mark WM via the beam splitter 3 , the reticle R, and the projection optical system 1 . FIG. 2A illustrates an exemplary wafer mark WM which includes a plurality of same lattice patterns. The luminous flux reflects on the wafer mark WM and returns to the beam splitter 3 via the projection optical system 1 and the reticle R. Furthermore, the luminous flux reflects on the beam splitter 3 and, via the imaging optical system 5 , forms an image of the wafer mark WM on an imaging plane of the imaging unit 6 . [0007] The imaging unit 6 applies photoelectric conversion to the image of the wafer mark WM. The A/D conversion circuit 7 converts the image signal into a two-dimensional digital signal sequence. The integrating circuit 8 receives the two-dimensional digital signal sequence from the A/D conversion circuit 7 and integrates the received digital signal sequence in the Y-direction of FIG. 2A . In other words, the integrating circuit 8 converts the two-dimensional digital signal into a one-dimensional digital signal sequence S 0 ( x ) as illustrated in FIG. 2B . The image processing unit 9 measures a central position of the wafer mark WM based on the converted digital signal sequence, or measures a contrast value as an index for searching a focal position of the optical system. [0008] The above-described mark imaging method is effective when an apparatus requires an accurate waveform of a mark signal. However, as illustrated in FIG. 3A , an x-axis, y-axis or z-axis position of the stage 11 fluctuates during a mark image capturing operation. The position may vibrate or move away from the initially set position (x-axis position x 0 , y-axis position y 0 , or z-axis position z 0 ). [0009] Accordingly, the integrating circuit 8 cannot generate an ideal digital signal sequence S 0 ( x ) illustrated in FIG. 2B , and generates a deformed signal sequence S 1 ( x ) due to fluctuation of the stage 11 as illustrated FIG. 2C . The deformed signal sequence S 1 ( x ) may induce measurement errors in image processing, such as a contrast measurement or a pattern matching. [0010] To solve the above-described problem, as discussed in Japanese Patent Application Laid-Open No. 6-36990 or in Japanese Patent Application Laid-Open No. 2003-203839, there is a conventional method for correcting an alignment measurement value or a deformation value of the digital signal sequence based on a continuously monitored stage position during an image accumulation operation. [0011] However, as illustrated in FIG. 3B , the luminous intensity of the alignment illumination unit 2 may fluctuate during an image accumulation operation. In this case, the above-described conventional method cannot accurately correct an alignment measurement value or a deformation value of the digital signal sequence. When the luminous intensity of the alignment illumination unit 2 has a peak value in a temporal distribution, or when the illumination unit 2 emits pulsed light, similar problems may arise. SUMMARY OF THE INVENTION [0012] Exemplary embodiments of the present invention are directed to an apparatus and technique capable of improving accuracy in a mark position measurement. [0013] According to an aspect of the present invention, an exposure apparatus performs a relative alignment between a reticle and a substrate and exposes the substrate to light via a pattern formed on the reticle. The exposure apparatus includes a movable stage that carries one of the reticle and the substrate, and a position measurement apparatus that measures a position of at least one of the reticle and the substrate. The position measurement apparatus includes an illumination unit configured to emit light toward a mark that indicates the position of the reticle or the substrate, a light intensity measurement unit configured to measure an intensity of the light, an imaging unit configured to capture an image of the mark, a stage position measurement unit configured to measure a position of the stage, and a signal waveform correction unit configured to correct a signal waveform output from the imaging unit based on a change in stage position and a change in illumination light intensity during a period of time the imaging unit captures the image of the mark. [0014] According to another aspect of the present invention, an exposure apparatus performs a relative alignment between a reticle and a substrate and exposes the substrate to light via a pattern formed on the reticle. The exposure apparatus includes a movable stage that carries one of the reticle and the substrate, and a position measurement apparatus that measures a position of at least one of the reticle and the substrate. The position measurement apparatus includes an illumination unit configured to emit light toward a mark that indicates the position of the reticle or the substrate, a light intensity measurement unit configured to measure an intensity of the light, an imaging unit configured to capture an image of the mark, a stage position measurement unit configured to measure a position of the stage, and a mark position correction unit configured to determine an average stage position representing an average position of the stage during an image capturing operation based on a change in stage position and a change in illumination light intensity during a period of time the imaging unit captures the image of the mark, and correct a mark position obtained based on a signal waveform output from the imaging unit with reference to the average stage position. [0015] According to yet another aspect of the present invention, an exposure apparatus performs a relative alignment between a reticle and a substrate and exposes the substrate to light via a pattern formed on the reticle. The exposure apparatus includes a movable stage that carries one of the reticle and the substrate, and a position measurement apparatus that measures a position of at least one of the reticle and the substrate. The position measurement apparatus includes an illumination unit configured to emit light toward a mark that indicates the position of the reticle or the substrate, a light intensity measurement unit configured to measure an intensity of the light, an imaging unit configured to capture an image of the mark, a stage position measurement unit configured to measure a position of the stage, and an imaging control unit configured to cause the imaging unit to initiate the processing for capturing an image of the mark after a position change of the stage and an intensity change of illumination light fall within allowable ranges. [0016] According to yet another aspect of the present invention, an exposure apparatus performs a relative alignment between a reticle and a substrate and exposes the substrate to light via a pattern formed on the reticle. The exposure apparatus includes a movable stage that carries one of the reticle and the substrate, and a position measurement apparatus that measures a position of at least one of the reticle and the substrate. The position measurement apparatus includes an illumination unit configured to emit light toward a mark that indicates the position of the reticle or the substrate, a light intensity measurement unit configured to measure an intensity of the light, an imaging unit configured to capture an image of the mark, a stage position measurement unit configured to measure a position of the stage, and an imaging control unit configured to cause the imaging unit to repeat the processing for capturing an image of the mark when a position change of the stage and an intensity change of illumination light are outside allowable ranges. [0017] Further features and aspects of the present invention will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0018] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments and features of the invention and, together with the description, serve to explain at least some of the principles of the invention. [0019] FIG. 1 illustrates an exposure apparatus capable of manufacturing semiconductor devices according to a first exemplary embodiment of the present invention. [0020] FIGS. 2A to 2C illustrate an exemplary mark used in the exposure apparatus illustrated in FIG. 1 and mark imaging signals. [0021] FIGS. 3A to 3C illustrate an exemplary method for calculating a weighting function based on a change in illumination light intensity and a stage position change in a direction perpendicular to an optical axis of the exposure apparatus illustrated in FIG. 1 . [0022] FIGS. 4A to 4C illustrate an exemplary method for calculating a weighting function in a case where the exposure apparatus illustrated in FIG. 1 causes a large change in stage position which exceeds a pixel resolution. [0023] FIGS. 5A and 5B illustrate an illumination light intensity and a weighting function in relation to a stage position of the exposure apparatus illustrated in FIG. 1 . [0024] FIG. 6 illustrates an exposure apparatus capable of manufacturing semiconductor devices according to a third exemplary embodiment of the present invention. [0025] FIG. 7 illustrates an exposure apparatus capable of manufacturing semiconductor devices according to a fourth exemplary embodiment of the present invention. [0026] FIG. 8 illustrates a conventional exposure apparatus capable of manufacturing semiconductor devices. [0027] FIG. 9 is a flowchart illustrating exemplary manufacturing processes of a semiconductor device. DETAILED DESCRIPTION OF THE EMBODIMENTS [0028] The following description of exemplary embodiments is illustrative in nature and is in no way intended to limit the invention, its application, or uses. It is noted that throughout the specification, similar reference numerals and letters refer to similar items in the following figures, and thus once an item is described in one figure, it may not be discussed for following figures. Exemplary embodiments will be described in detail below with reference to the drawings. [0029] An exposure apparatus according to an exemplary embodiment of the present invention is configured to continuously measure a momentary position of a stage and the intensity of illumination light while an imaging system captures an image (i.e., stores electric charge of an image signal) of a mark on the stage. Then, the exposure apparatus corrects the signal sequence S 1 ( x ) illustrated in FIG. 2C referring to a stage position distribution and a luminous intensity distribution during an image accumulation operation. Thus, the exposure apparatus can obtain an ideal digital signal sequence S 0 ( x ) illustrated in FIG. 2B . The mark used in an exemplary embodiment is, for example, a mark formed on a wafer (e.g., a silicon or glass plane) placed on a stage or formed on a fixed plane of the stage. First Exemplary Embodiment [0030] FIG. 1 illustrates an exposure apparatus capable of manufacturing semiconductor devices according to a first exemplary embodiment of the present invention. In FIG. 1 , “R” represents a reticle, “W” represents a wafer (i.e., a substrate to be exposed), and “WM” represents a wafer mark. A projection optical system 1 has an optical axis parallel to a z-axis of the xyz-coordinate system. A mark imaging optical system S includes a light source 2 , two beam splitters 3 and 17 , two imaging optical systems 4 and 5 , an imaging unit 6 (e.g., CCD), an illumination light intensity measurement unit 15 measuring an intensity of light emitted toward the wafer mark WM, and an illumination light intensity storage circuit 16 . [0031] An analog/digital (A/D) conversion circuit 7 receives an analog image signal from the mark imaging optical system S and converts the input analog signal into a digital signal. An integrating circuit 8 generates a one-dimensional digital signal sequence. An image processing circuit 9 performs predetermined processing on an input image signal. A movable stage 11 can cause a three-dimensional movement in the xyz-coordinate system. Namely, the stage 11 moves in x-, y-, and z-axis directions. A stage driving unit 10 drives the movable stage 11 . A stage position measurement unit 12 , such as a laser interferometer, measures a momentary position of the stage 11 on a plane normal to the optical axis extending in the x- and y-axis directions. A stage position storage circuit 13 stores a measurement result (position data) obtained by the stage position measurement unit 12 . A waveform correction circuit 14 corrects the digital signal sequence produced from the integrating circuit 8 . [0032] Next, exemplary mark imaging processing and signal waveform correction processing performed by the exposure apparatus illustrated in FIG. 1 is described below. First, the stage driving unit 10 moves the stage 11 to a position where the position measurement unit 12 can observe the wafer mark WM on the stage 11 . Next, the light source 2 emits a luminous flux (i.e., light having a wavelength similar to the exposure light to be used for exposing the wafer W) which reaches the wafer mark WM via the beam splitters 17 and 3 , the imaging optical system 4 , the reticle R, and the projection optical system 1 . [0033] FIG. 2A illustrates an exemplary wafer mark WM which includes a plurality of same lattice patterns. The luminous flux reflects on a surficial region including the wafer mark WM (i.e., an observed plane) and returns to the beam splitter 3 via the projection optical system 1 and the reticle R. Furthermore, the luminous flux reflects on the beam splitter 3 and, via the imaging optical system 5 , forms an image of the wafer mark WM on an imaging plane of the imaging unit 6 . [0034] The imaging unit 6 applies photoelectric conversion to the image of the wafer mark WM. The imaging unit 6 outputs an imaging signal (i.e., a signal indicating accumulation of electric charge) to the stage position storage circuit 13 and the illumination light intensity storage circuit 16 . When the imaging signal is in an ON state, the position measurement unit 12 continuously measures the position of the stage 11 . Similarly, the illumination light intensity measurement unit 15 continuously measures the intensity of illumination light. The stage position storage circuit 13 stores the measured stage position, and the illumination light intensity storage circuit 16 stores the measured illumination light intensity. [0035] The A/D conversion circuit 7 receives the mark image signal having been subjected to the photoelectric conversion (charge accumulation) processing from the imaging unit 6 and converts the received image signal into a two-dimensional digital signal sequence S(x,y). [0036] The integrating circuit 8 receives the digital signal sequence S(x,y) from the A/D conversion circuit 7 and integrates the digital signal sequence S(x,y) in the Y-direction of FIG. 2A as illustrated in FIG. 2C . Namely, the integrating circuit 8 converts the two-dimensional digital signal sequence into a one-dimensional digital signal sequence S 1 ( x ). [0037] FIG. 3A illustrates a temporal change of the stage position stored in the stage position storage circuit 13 during an imaging operation (charge accumulation operation). FIG. 3B illustrates a temporal change of the illumination light intensity stored in the illumination light intensity storage circuit 16 . [0038] The waveform correction circuit 14 serving as a mark position correction unit multiplies the stage position change (data) illustrated in FIG. 3A and the illumination light intensity change (data) illustrated in FIG. 3B . The waveform correction circuit 14 separately integrates vibration components in the +x direction and vibration components in the −x direction as illustrated in FIG. 3C . [0039] The waveform correction circuit 14 obtains a vibration component weighting factor Sp in the +x direction and a vibration component weighting factor Sm in the −x direction based on the integrated data. [0040] As illustrated in TABLE 1, the waveform correction circuit 14 calculates the following 1st-order simultaneous equations with respect to (xe−xs+1) variables based on the digital signal sequence S 1 ( x ) and the obtained weighting factors Sp and Sm in the range of x (xs≦x≦xe). [0000] TABLE 1 ( S   1  ( xs ) S   1  ( xs + 1 ) S   1  ( xs + 2 ) ⋮ S   1  ( xn - 1 ) S   1  ( xn ) S   1  ( xn + 1 ) ⋮ S   1  ( xe - 2 ) S   1  ( xe - 1 ) S   1  ( xe ) ) = ( 1 - Sp Sp Sm Ss Sp Sm Ss Sp 0 ⋮ Sm Ss Sp Sm Ss Sp Sm Ss Sp ⋮ 0 Sm Ss Sp Sm Ss Sp Sm 1 - Sm ) · ( S   0  ( xs ) S   0  ( xs + 1 ) S   0  ( xs + 2 ) ⋮ S   0  ( xn - 1 ) S   0  ( xn ) S   0  ( xn + 1 ) ⋮ S   0  ( xe - 2 ) S   0  ( xe - 1 ) S   0  ( xe ) )  Ss = 1 − Sm − Sp In this case, as illustrated in FIG. 2C, the setting position of xs and xe is outside a region of the wafer mark WM, where the signal sequence S 1 ( x ) has a constant value and does not receive any effect from fluctuation in the stage position. [0041] The waveform correction circuit 14 serving as the mark position correction unit solves the above-described 1st-order simultaneous equations with respect to the (xe−xs+1) variables according to the Gaussian elimination widely used for numerical calculations. Then, the waveform correction circuit 14 can obtain the signal sequence S 0 ( x ) in the range of xs≦x≦xe illustrated in FIG. 2B , as a result of correction applied to the stage vibration component considering the illumination light intensity change. [0042] The image processing circuit 9 measures a central position of the wafer mark WM using the corrected digital signal sequence S 0 ( x ), or measures a contrast value of the digital signal sequence S 0 ( x ) (i.e., a contrast value of the mark image) to detect a focal position (best-focused position) of the projection optical system 1 . [0043] An exemplary embodiment obtains the weighting components Sm and Sp of neighboring pixels for the above-described correction, based on an assumption that a position change of the stage 11 is generally smaller than a pixel resolution of the imaging unit 6 and S 1 (xn) can be determined based on three data of S 0 (xn−1), S 0 (xn), and S 0 (xn+1). [0044] If the position change of the stage 11 is dependent on two preceding pixels and two succeeding pixels, the waveform correction circuit 14 can dissect the vibration component into plural regions according to the pixel resolution as illustrated in FIG. 4A . Then, as illustrated in FIG. 4C , the waveform correction circuit 14 can obtain weighting factors Sm 2 , Sm 1 , Ss, Sp 1 , and Sp 2 corresponding to S 0 (xn−2), S 0 (xn−1), S 0 (xn), S 0 (xn+1), and S 0 (xn+2), and perform the waveform correction using the obtained weighting factors. If the position change of the stage 11 is dependent on three or more preceding and succeeding pixels, the waveform correction circuit 14 can perform the waveform correction according to a similar procedure. [0045] Furthermore, if a longer processing time is unacceptable, the waveform correction circuit 14 can skip the waveform correction to reduce the processing time. In this case, the waveform correction circuit 14 can use a correction value (mark position) representing an average stage position obtainable according to the weighting function that multiplies the stage position fluctuation with the illumination light intensity change. [0046] If the weighting factors Sm and Sp exceed predetermined setting ranges (allowable ranges) due to large variations in the stage position change and the illumination light intensity change, the waveform correction circuit 14 functioning as an imaging controller can cause an imaging unit 6 to re-execute the processing for capturing an image of the mark MW. [0047] Furthermore, if continuous monitoring of the stage position or the illumination light intensity is feasible before starting an imaging operation (or during a preparation for the imaging operation), the waveform correction circuit 14 functioning as the imaging controller can cause an imaging unit 6 to postpone the processing for capturing an imaging of the mark MW until a deviation or dispersion falls within a predetermined range. [0048] The above-described exemplary embodiment uses a mark capable of measuring the position in the x-axis direction and performs the position measurement in the x-axis direction. However, if rotated by 90 degrees, the above-described mark can be used for position measurement in the y-axis direction. The waveform correction circuit 14 can perform the waveform correction for the position measurement in the y-axis direction according to a procedure similar to the above-described procedure in the x-axis direction. Second Exemplary Embodiment [0049] According to the first exemplary embodiment, the stage driving unit 10 moves the stage 11 to a position where the position measurement unit 12 can observe the wafer mark WM on the stage 11 and stops the stage 11 to execute a mark position measurement. A second exemplary embodiment is different from the first exemplary embodiment in performing the mark position measurement when the stage 11 is moving. [0050] The exposure apparatus according to the second exemplary embodiment has a hardware arrangement similar to that of the first exemplary embodiment and is not described below. First, the stage driving unit 10 moves the stage 11 . The position measurement unit 12 starts the mark position measurement after the wafer mark WM on the stage 11 enters an observation range of the imaging unit 6 . The mark position measurement includes emitting a luminous flux from the light source 2 and illuminating the wafer mark WM via the beam splitters 17 and 3 , the imaging optical system 4 , the reticle R, and the projection optical system 1 . FIG. 2A illustrates an exemplary wafer mark WM which includes a plurality of same lattice patterns. [0051] The luminous flux reflects on a surficial region including the wafer mark WM and returns to the beam splitter 3 via the projection optical system 1 and the reticle R. Furthermore, the luminous flux reflects on the beam splitter 3 and, via the imaging optical system 5 , forms an image of the wafer mark WM on an imaging plane of the imaging unit 6 . The imaging unit 6 applies photoelectric conversion to the image of the wafer mark WM. The imaging unit 6 outputs an imaging signal (i.e., a signal indicating accumulation of electric charge) to the stage position storage circuit 13 and the illumination light intensity storage circuit 16 . [0052] When the imaging signal is in an ON state, the position measurement unit 12 continuously measures the position of the stage 11 while the illumination light intensity measurement unit 15 continuously measures the intensity of illumination light. The stage position storage circuit 13 stores the measured stage position, and the illumination light intensity storage circuit 16 stores the measured illumination light intensity. The A/D conversion circuit 7 receives the mark image signal having been subjected to the photoelectric conversion (charge accumulation) processing from the imaging unit 6 and converts the received signal into a two-dimensional digital signal sequence S(x,y). The integrating circuit 8 receives the digital signal sequence S(x,y) from the A/D conversion circuit 7 and integrates the received digital signal sequence S(x,y) in the Y-direction of FIG. 2A . In other words, the integrating circuit 8 converts the two-dimensional digital signal sequence S(x,y) into a one-dimensional digital signal sequence S 1 ( x ) as illustrated in FIG. 2C . [0053] FIG. 5A illustrates a temporal position change of the stage 11 stored in the stage position storage circuit 13 during an imaging operation (image accumulation operation of the imaging unit 6 ). In this case, the stage 11 is moving in the −x direction. FIG. 5B illustrates a temporal change of the illumination light intensity stored in the illumination light intensity storage circuit 16 during the imaging operation. [0054] The waveform correction circuit 14 calculates weighting factors (W 0 , W 1 , W 2 , - - - , WN) of respective pixels based on the graph of FIG. 5B that illustrates the illumination light intensity change. Each pixel has a time width equivalent to a ratio of the pixel resolution of the imaging unit 6 to the moving speed of the stage 11 . [0055] The waveform correction circuit 14 calculates the following 1st-order simultaneous equations with respect to (xe−xs+1) variables based on the digital signal sequence S 1 ( x ) in the range of x (xs≦x≦xe). [0000] [ S   1  ( xs ) S   1  ( xs + 1 ) S   1  ( xs + 2 ) ⋮ S   1  ( xn - 1 ) S   1  ( xn ) S   1  ( xn + 1 ) ⋮ S   1  ( xe - 2 ) S   1  ( xe - 1 ) S   1  ( xe ) ] = [ W   0 W   1 W   2 … Wn W   0 W   1 W   2 … W   N 0 W   0 W   1 W   2 … W   N ⋮ ⋮ W   0 W   1 W   2 … W   N ⋮ ⋮ 0 W   0 W   1 Σ   Wi  ( i > 1 ) W   0 Σ   Wi  ( i > 0 ) Σ   Wi ] · [ S   0  ( xs ) S   0  ( xs + 1 ) S   0  ( xs + 2 ) ⋮ S   0  ( xn - 1 ) S   0  ( xn ) S   0  ( xn + 1 ) ⋮ S   0  ( xe - 2 ) S   0  ( xe - 1 ) S   0  ( xe ) ] In this case, as illustrated in FIG. 2C, the setting position of xs and xe is outside a region of the wafer mark WM, where the signal sequence S 1 ( x ) has a constant value and does not receive any effect from fluctuation in the stage position. [0056] The waveform correction circuit 14 solves the above-described 1st-order simultaneous equations with respect to the (xe−xs+1) variables according to the Gaussian elimination widely used for numerical calculations. Then, the waveform correction circuit 14 can obtain the signal sequence S 0 ( x ) in the range of xs≦x≦xe illustrated in FIG. 2B , as a result of correction applied to the stage vibration component considering the illumination light intensity change. [0057] The image processing circuit 9 measures a central position of the wafer mark WM using the corrected digital signal sequence S 0 ( x ), or measures a contrast value of the digital signal sequence S 0 ( x ) (i.e., a contrast value of the mark image) to detect a focal position (best-focused position) of the projection optical system 1 . [0058] Although the above-described exemplary embodiment uses a mark for a position measurement in the x-axis direction, a similar mark can be used for a position measurement in the y-axis direction to perform the waveform correction in the same manner. Furthermore, if a longer processing time is unacceptable, the waveform correction circuit 14 can skip the waveform correction to reduce the processing time. In this case, the waveform correction circuit 14 can use a correction value (mark position) representing an average stage position obtainable according to the weighting function that multiplies the stage position fluctuation with the illumination light intensity. Third Exemplary Embodiment [0059] FIG. 6 illustrates an exposure apparatus capable of manufacturing semiconductor devices according to a third exemplary embodiment of the present invention. In FIG. 6 , “R” represents a reticle, “W” represents a wafer (i.e., a substrate to be exposed), and “WM” represents a wafer mark. A projection optical system 1 has an optical axis parallel to a z-axis of the xyz-coordinate system. A mark imaging optical system S includes a light source 2 , two beam splitters 3 and 17 , two imaging optical systems 4 and 5 , an imaging unit 6 (e.g., CCD), an illumination light intensity measurement unit 15 measuring an intensity of light emitted toward the wafer mark WM, and an illumination light intensity storage circuit (unit) 16 . [0060] An analog/digital (A/D) conversion circuit 7 receives an analog image signal from the mark imaging optical system S and converts the input analog signal into a digital signal. An integrating circuit 8 generates a one-dimensional digital signal sequence. An image processing circuit 9 performs predetermined processing on an input image signal. A movable stage 11 can cause a three-dimensional movement in the xyz-coordinate system. Namely, the stage 11 moves in x-, y-, and z-axis directions. A stage driving unit 10 drives the movable stage 11 . A stage position measurement unit 12 , such as a laser interferometer, measures a momentary position of the stage 11 in the x- and y-axis directions. A stage position storage circuit 13 stores a measurement result (position data) obtained by the stage position measurement unit 12 . A waveform correction circuit 14 corrects the digital signal sequence produced from the integrating circuit 8 . [0061] The first and second exemplary embodiments are configured to capture an image of the wafer mark WM via the reticle R. However, the third exemplary embodiment can directly capture an image of the wafer mark WM on the stage 11 without using the reticle R. The exposure apparatus according to the third exemplary embodiment performs mark imaging processing and signal waveform correction processing which are similar to those described in the first and second exemplary embodiments. Fourth Exemplary Embodiment [0062] FIG. 7 illustrates an exposure apparatus capable of manufacturing semiconductor devices according to a fourth exemplary embodiment of the present invention. The exposure apparatus according to the fourth exemplary embodiment can directly capture an image of the wafer mark WM on the stage 11 without using the reticle R and the projection optical system 1 . The exposure apparatus according to the fourth exemplary embodiment performs mark imaging processing and signal waveform correction processing which are similar to those described in the first and second exemplary embodiments. [0063] As described above, the above-described exemplary embodiments can correct a change in the imaging signal waveform caused by a change in stage position or a change in illumination light intensity during a mark imaging operation, and can perform accurate image processing. Furthermore, an exemplary embodiment can perform a mark position measurement before the stage 11 perfectly stops. An exemplary embodiment can perform a mark position measurement while the stage 11 is not stopped or is continuously moving. Thus, the exemplary embodiments can realize a high-throughput exposure system. [0064] Especially, when the above-described signal waveform correction method is employed, an exposure apparatus can accurately perform contrast measurement processing and pattern matching processing in the manufacturing of a semiconductor device even if the alignment illumination light source is a pulsed light source or a light source causing a large temporal change in the illumination light intensity. Therefore, the above-described exemplary embodiments can bring various effects in the focal position measurement and the mark position measurement. Fifth Exemplary Embodiment [0065] Exemplary manufacturing processes of a micro device (such as a semiconductor chip (e.g., IC or LSI), a liquid crystal panel, a CCD, a thin-film magnetic head, or a micro machine) using the above-described exposure apparatus is described below. [0066] FIG. 9 is a flowchart illustrating exemplary manufacturing processes of a semiconductor device. Step S 1 (i.e., a circuit design process) is for designing a circuit of a semiconductor device. Step S 2 (i.e., a mask making process) is for fabricating a mask that forms a designed pattern. Step S 3 (i.e., a wafer manufacturing process) is for manufacturing a wafer from a silicon or comparable material. Step S 4 is a wafer process (which is referred to as “preprocess”) for forming an actual circuit on a wafer using an exposure apparatus with the above-described prepared mask according to the lithography technique. [0067] Step S 5 is an assembling process (which is referred to as “postprocess”) for forming a semiconductor chip using the wafer manufactured in step S 4 . The post process includes an assembly process (e.g., dicing, bonding, etc) and a packaging process (chip sealing). Step S 6 (i.e., an inspection process) is for inspecting the semiconductor device manufactured in step S 5 . The inspection includes an operation confirmation test and an endurance test. Step S 7 (i.e., a shipment process) is for shipping the semiconductor device completed through the above-described processes. [0068] The above-described wafer process in step S 4 includes an oxidation step of oxidizing a wafer surface, a chemical vapor deposition (CVD) step of forming an insulating film on the wafer surface, and an electrode formation step of forming electrodes on the wafer by vaporization. [0069] Furthermore, the wafer process includes an ion implantation step of implanting ions into the wafer, a resist processing step of coating the wafer with a photosensitive material, and an exposure step of exposing the wafer subjected to the resist processing step to light using the above-described exposure apparatus with a mask having a circuit pattern. [0070] Furthermore, the wafer process in step S 4 includes a developing step of developing the wafer exposed in the exposure step, an etching step of cutting a portion other than a resist image developed in the developing step, and a resist separating step of removing unnecessary resist remaining after the etching step is accomplished. The processing repeating the above-described steps can form multiple circuit patterns on a wafer. [0071] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all modifications, equivalent structures, and functions. [0072] This application claims priority from Japanese Patent Application No. 2006-341055 filed Dec. 19, 2006, which is hereby incorporated by reference herein in its entirety.

An exposure apparatus performs a relative alignment between a reticle and a substrate, and exposes the substrate to light via a pattern formed on the reticle. The exposure apparatus includes a movable stage that carries one of the reticle and the substrate and a position measurement apparatus that measures a position of at least one of the reticle and the substrate. The position measurement apparatus includes an illumination unit configured to emit light toward a mark that indicates the position of the reticle or the substrate, a light intensity measurement unit configured to measure an intensity of the light, an imaging unit configured to capture an image of the mark, a stage position measurement unit configured to measure a position of the stage, and a signal waveform correction unit configured to correct a signal waveform output from the imaging unit based on a change in stage position and a change in illumination light intensity.

CLAIM OF PRIORITY The present application claims priority to the following provisional application, the contents of which are incorporated by reference herein in their entirety: U.S. Provisional Patent Application No. 60/598,315, entitled SYSTEM AND METHOD FOR RUNTIME INTERFACE VERSIONING, by Neil Smithline, filed on Aug. 3, 2004. CROSS REFERENCE TO RELATED APPLICATIONS The present application relates to the following application, the contents of which are hereby incorporated by reference in their entirety: U.S. patent application Ser. No. 10/373,532 entitled SYSTEM AND METHOD FOR ENTERPRISE AUTHENTICATION, by Paul Patrick, filed on Feb. 24, 2003. COPYRIGHT NOTICE A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. FIELD OF THE INVENTION The present invention relates to systems, methods and computer readable media for upgrading servers. The present invention relates more particularly to enabling interoperability between related software products that are designed to work with different versions of servers. BACKGROUND OF THE INVENTION Since its inception in 1995, the Java™ programming language has become increasingly popular. (Java™ is a trademark of Sun Microsystems, Inc.) Java, which is an interpreted language, enabled the creation of applications that could be run on a wide variety of platforms. This ability to function across a variety of different client platforms, i.e. platform independence, and Java's relatively easy implementation of network applications has resulted in its use in endeavors as basic as personal webpages to endeavors as complex as large business-to-business enterprise systems. As Java has become more commonplace, a wide variety of tools and development platforms have been created to assist developers in the creation and implementation of applications and portals using Java or other languages supporting platform independence. Many of such applications and portals are based around one or more servers that provide, inter alia, application support and control access to resources. It is often desirable to enable third parties to produce custom software modules or plugins that can be inserted into such servers to perform functions that would otherwise be performed by the base software of the server. Server architectures can be designed to enable easy development of plugins for certain features such as security. However, as the interfaces through which the plugins interact with the server are upgraded, plugins that were designed for previous versions of the interfaces may be rendered incompatible. The process of upgrading the plugins can be time consuming and expensive. What is needed is an improved interface that allows legacy plugin products to be used with newer plugin interfaces. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating one embodiment of a security framework. FIG. 2 is a block diagram illustrating one embodiment of an interaction among a security provider interface, an adapter, and a security provider. FIG. 3 is a block diagram illustrating another high-level view of an adapter in an embodiment. FIG. 4 is a flow chart illustrating one embodiment of a process for utilizing a security provider. DETAILED DESCRIPTION The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. References to embodiments in this disclosure are not necessarily to the same embodiment, and such references mean at least one. While specific implementations are discussed, it is understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without departing from the scope and spirit of the invention. In the following description, numerous specific details are set forth to provide a thorough description of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail so as not to obscure the invention. Although a diagram may depict components as logically separate, such depiction is merely for illustrative purposes. It can be apparent to those skilled in the art that the components portrayed can be combined or divided into separate software, firmware and/or hardware components. For example, one or more of the embodiments described herein can be implemented in a network accessible device/appliance such as a router. Furthermore, it can also be apparent to those skilled in the art that such components, regardless of how they are combined or divided, can execute on the same computing device or can be distributed among different computing devices connected by one or more networks or other suitable communication means. In accordance with embodiments, there are provided mechanisms and methods for versioning plugin adapters for servers. These mechanisms and methods can enable embodiments to provide legacy versions of software plugins the capability to function when the interfaces configured to accept the plugins are upgraded. The ability of embodiments to provide plugins with the capability to function when the interfaces configured to accept the plugins are upgraded can enable easier migrations to new versions, extended use from legacy plugins and so forth. In an embodiment, a method for utilizing a plugin product for a server is provided. The plugin product can have an old interface version. One embodiment of the method includes accepting a request directed towards a new interface version of the plugin. The request directed towards the new interface version is converted to a request directed towards the old interface version. The request directed towards the old interface version is transmitted to the plugin. In some embodiments, the request may be a request directed to a security provider. In various embodiments, accepting a request to a security provider accessible via the plugin can include accepting a request for any of: an authentication system, an identity assertion system, an authorization system, and an auditing system. While the present invention is described with reference to an embodiment in which security providers create executable adapter programs written in the Java™ programming language that are executed in conjunction with plugin interfaces adapted to work with legacy versions of software, the present invention is not limited to security providers, nor to the Java™ programming language and may be practiced using other programming languages, i.e., JSP and the like without departing from the scope of the embodiments claimed. (Java™ is a trademark of Sun Microsystems, Inc.) In one embodiment, the servers utilize an application server product, such as WebLogic® Server by BEA systems of San Jose, Calif. FIG. 1 is a block diagram illustrating one embodiment of a security framework of a server. In one embodiment, the server is a Java server. The security framework includes a resource container 118 containing resources 105 , 110 , and 115 . Preferably, the resource container contains all of the resources required by a particular activity or particular group of activities. The resources include information and programs that will be utilized within the activities. The resource container is configured to provide the resources in response to an approved request from a security framework 122 . The security framework 122 includes multiple Service Provider Interfaces (SPIs). These interfaces may also be referred to as Security Provider Interfaces. The SPIs are configured to access security providers that provide security verification services for users attempting access the resources 105 , 110 , and 115 . The SPIs include an authentication SPI 125 . The authentication SPI 125 is configured to utilize an external authentication provider 140 to verify a user's credentials. The authentication provider 140 accepts credentials from a user and uses those credentials to verify the user's identity. The authentication provider 140 , like the identity assertion provider 145 , authorization provider 150 , and adjudication provider 155 is a software plugin that interacts with the security framework 122 through the SPIs. The credentials utilized by the authentication provider can include usernames and passwords, secure tokens, biometric data, secure hardware keys, or any other credentials that can be used to verify a user identity. The authentication provider returns to the security framework 122 a value indicating whether the user has been successfully authenticated and information about the user (e.g. what groups the user belongs to). Another type of SPI is an identity assertion SPI 130 . The identity assertion SPI 130 is configured to accept identity assertions for users from external systems such as the identity assertion provider 145 . The identity assertion SPI can be configured for multiple provider types, including multiple tokens and certificates for verifying a user's identity. The identity assertion SPI provides a response to an authentication request indicating whether a user is permitted to access the resource. An authorization SPI 135 is configured to use an authorization provider 150 to determine whether a user is permitted to access a resource. Once a user's identity has been established through the authentication provider 140 or the identity assertion provider, the authorization provider 150 determines whether the user as currently identified is permitted to access the resource. The security framework also includes an auditing SPI 120 . In some embodiments, the various SPIs can utilize multiple providers. The auditing SPI 120 utilizes an auditing provider 158 to record the various responses from the differing security providers. An adjudication SPI 138 and adjudication provider 155 are configured to resolve a conflict when one exists. For example, in some embodiments, the authentication SPI 125 can utilize multiple authorization providers 150 . If some return a successful authentication and some return an unsuccessful authentication in response to an authentication request, the adjudication provider 155 determines whether the user should be authenticated. In some embodiments, an administrator can set adjudication criteria indicating how conflicts are resolved. For example, the criteria could be set such that a successful authentication from any of the providers, or all of the providers is needed for a user to be considered authenticated. In some embodiments, the security provider also includes role mapping SPIs, credential mapping SPIs and other SPIs for outsourcing security functions to plugins. FIG. 2 is a block diagram illustrating one embodiment of an interaction among a security provider interface 215 , an adapter 210 , and a security provider 205 in an embodiment. The legacy security provider 205 is one of the service providers 140 , 145 , 150 , 155 illustrated in FIG. 1 . The SPI 215 is one of the SPIs 125 , 130 , 135 , 138 , 158 illustrated in FIG. 1 . The SPI 215 has a set of interface parameters governing how it will interact with the security provider 205 . These parameters indicate the formatting and content of data transmitted to and received from the security provider 205 . As new versions of the SPI are released, these interface parameters can change, thus requiring that the security provider 205 be updated to interact with the SPIs correctly. However, security providers are often difficult to update, requiring considerable amounts of time and expense. Thus, legacy providers 205 often remain in place long after the SPI 215 is updated. Thus, an adapter 210 is used to translate information passed between the SPI 215 and the security provider 205 . The adapter 210 receives communications from the SPI 215 configured for a new version of the provider 205 , and translates the communications into communications configured for the legacy version of the provider 215 . The adapter also receives communications configured for the legacy version of the SPI and converts the communications to communications designed for the new version of the SPI. In some embodiments, the adapter 210 “wraps” the service provider, generating a new service provider object that interacts with SPI as a provider 215 , but is capable of converting requests between versions. FIG. 3 is a block diagram illustrating another high-level view of an adapter in an embodiment. The adapter includes an input module 305 that is configured to receive communications from either the SPI 205 or the security provider. These communications are passed to a translator 310 . The translator 310 receives the communications and according to the type of communications, translates them as necessary. The translator 310 preferably stores information indicating a version of the SPI 205 and the security provider 215 . In some embodiments, the translator can translate between multiple differing versions of the SPI and providers. When the translator 310 receives input from the SPI 205 or the provider 215 through the input module, it converts it to output that is configured for the type of the destination and passes it to an output module 315 . While in the present embodiment, the adapter 210 is used to bridge communications between legacy security providers and new SPIs, in alternate embodiments, adapters can be used to enable any type of plugin having similar compatibility issues. Disclosed below is computer code for implementing an adapter for an authorization provider in an embodiment. package weblogic.security.service.adapters; import javax.security.auth.login.AppConfigurationEntry; import weblogic.security.spi.AuthenticationProvider; import weblogic.security.spi.AuthenticationProviderV2; import weblogic.security.spi.ChallengeIdentityAsserter; import weblogic.security.spi.ChallengeIdentityAsserterV2; import weblogic.security.spi.IdentityAsserter; import weblogic.security.spi.IdentityAsserterV2; import weblogic.security.spi.PrincipalValidator; public class AuthenticationProviderV1Adapter extends SecurityProviderV1Adapter implements AuthenticationProviderV2 { public AuthenticationProviderV1Adapter(AuthenticationProvider provider) { base = provider; } public AppConfigurationEntry getLoginModuleConfiguration() { AuthenticationProvider atn = (AuthenticationProvider) base; return atn.getLoginModuleConfiguration(); public AppConfigurationEntry getAssertionModuleConfiguration() { AuthenticationProvider atn = (AuthenticationProvider) base; return atn.getAssertionModuleConfiguration(); } public Principal Validator getPrincipalValidator() { AuthenticationProvider atn = (AuthenticationProvider) base; return atn.getPrincipalValidator(); } public IdentityAsserterV2 getIdentityAsserter() { AuthenticationProvider atn = (AuthenticationProvider) base; IdentityAsserter asserter = atn.getIdentityAsserter(); if (asserter instanceof ChallengeIdentityAsserter) { return new ChallengeIdentityAsserterV1Adapter((ChallengeIdentityAsserter)asserter); } else { return new IdentityAsserterV1Adapter(asserter); } } } FIG. 4 is a flow chart illustrating one embodiment of a process for utilizing a security provider. In block ( 405 ) the security framework 122 receives a request for a protected resource. In block ( 410 ) the security framework creates a provider object from the security provider. Creating a provider object can entail generating an object to perform the provider's tasks. In block ( 412 ), the system determines whether the provider object uses a current version of the interface or a legacy version. If the provider uses the current interface version, the process jumps to block ( 420 ), where the existing provider is utilized as the provider object. If the provider uses the legacy interface, the process moves to block ( 415 ), in which it wraps the existing provider around the adapter. In some embodiments, block ( 415 ) is implemented by the code disclosed below: SecurityProvider provider= AdapterFactory.getAuthenticationProvider(mbean, auditor); The code disclosed above utilizes an adapter factory to produce an adapter module instance, that with the SPI, communicates with the service provider. The security framework 122 does not need to be aware of any conversion steps being performed by the adapter, instead only receiving notification from the SPI of the response (i.e., successful/unsuccessful authentication/authorization etc.). In block ( 420 ), the security provider is utilized to return an authentication/authorization response. If the security provider and adapter have the same version, the adapter does not perform any conversion. The type of conversion depends on the level of change between the two versions of the plugin interface. For example, in the case of an improved identity assertion SPI, an original version of a method used to access the identity assertion provider might call the identity assertion provider with one argument, whereas the improved SPI calls the provider with two arguments. The adapter receives the two-argument call from the SPI, and makes a call to the provider with a single argument. The new wrapped security provider is used for future operations. In some embodiments, the creation of the provider object and wrapping of the adapter occurs during an initiation/bootup/deployment stage rather than when a specific request is received. It should also be understood that while a security provider is discussed as an exemplary embodiment, the embodiments discussed above can be applied to any type of software plugin. Other features, aspects and objects of the invention can be obtained from a review of the figures and the claims. It is to be understood that other embodiments of the invention can be developed and fall within the spirit and scope of the invention and claims. The foregoing description of preferred embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to the practitioner skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalence. In addition to an embodiment consisting of specifically designed integrated circuits or other electronics, the present invention may be conveniently implemented using a conventional general purpose or a specialized digital computer or microprocessor programmed according to the teachings of the present disclosure, as will be apparent to those skilled in the computer art. Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those skilled in the software art. The invention may also be implemented by the preparation of application specific integrated circuits or by interconnecting an appropriate network of conventional component circuits, as will be readily apparent to those skilled in the art. The present invention includes a computer program product which is a storage medium (media) having instructions stored thereon/in which can be used to program a computer to perform any of the processes of the present invention. The storage medium can include, but is not limited to, any type of disk including floppy disks, optical discs, DVD, CD-ROMs, microdrive, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of media or device suitable for storing instructions and/or data. Stored on any one of the computer readable medium (media), the present invention includes software for controlling both the hardware of the general purpose/specialized computer or microprocessor, and for enabling the computer or microprocessor to interact with a human user or other mechanism utilizing the results of the present invention. Such software may include, but is not limited to, device drivers, operating systems, and user applications. Included in the programming (software) of the general/specialized computer or microprocessor are software modules for implementing the teachings of the present invention.

The present invention provides methods, machine readable memories and systems for versioning plugin adapters for servers so as to allow legacy versions of software plugins to function when the interfaces configured to accept the plugins are upgraded. An adapter resides between a plugin interface and the plugin module and converts requests designed for a current or new version to requests designed for legacy versions. In some embodiments, the interface elements are designed to extend and adapt the functionality of a security apparatus by enabling the security apparatus to utilize third party security providers.

BACKGROUND OF THE INVENTION [0001] Tissue defects are sometimes repaired with porous scaffolds comprising biocompatable materials. The porous nature of the devices allows the inward migration of cells, followed by the in-growth of tissue, thereby repairing the defect. The pore structure must be controlled to ensure optimal inward cell migration (e.g., sized large enough to accommodate cells, and avoid altering the cell phenotype), from which the new tissue may form. Current devices do not adequately control pore geometry, size, and distribution, with processes that are economically attractive. Additionally, open porous networks facilitate cell migration throughout the implant, thereby speeding up regeneration. Also, mechanical properties of existing porous structures are less than desirable for applications where the implant is subjected to post implant stresses. The porous nature also minimizes the amount of foreign material placed into the patient. [0002] Most processes for producing porous biomaterial implants utilize a leaching method wherein a leachable substance such as sodium chloride is mixed with a biomaterial such as polymethylmethacrylate (PMMA) and later removed with a solvent such as water. U.S. Pat. No. 4,199,864 (Ashman), U.S. Pat. No. 4,636,526, (Dorman et al), and U.S. Pat. No. 5,766,618 (Laurencin et al), describe such methods. Such leaching methods are time consuming and in many instances only a portion of the leachable substance is effectively removed from the implant. [0003] Other processes for creating porous medical implants utilize a vacuum freezing operation as described in U.S. Pat. No. 6,306,424 (Vyakarnam, et al), U.S. Pat. No. 5,766,618 (Laurencin et al), and U.S. Pat. No. 5,133,755 (Brekke). These processes are not generally suited to mass production and often utilize non-biocompatable solvents. [0004] A “plasticized melt-flow” process (PMF) has been developed, in an effort to increase the strength, and reduce costs, of molded polymeric parts. Such a process is described in U.S. Pat. No. 6,169,122 (Blizard et al) and U.S. Pat. No. 6,231,942 (Blizard et al) and by David Pierick and Kai Jacobsen, “Injection Molding Innovation: The Microcellular Foam Process,” Plastics Engineering, May 2001, pp 46-51 (such disclosures being incorporated herein by reference). In general, such a process uses a gas (e.g., N 2 , or CO 2 ) under high pressures to create a supercritical fluid (SCF). The SCF, when depressurized, liberates the gas, thereby creating a porous structure. [0005] The pores in the PMF processes noted above are nucleated by nucleating agents which are added in the range of 2 to 7 percent. As a result the pores may be more homogeneously dispersed through the molded part, than pores seen in other processing methods known in the art. The Pierick-Jacobsen paper reports that the aim of this technology is reducing costs, through the reduction of polymer used and decreasing cycle time, i.e., nucleating agent takes the place of matrix polymer, thereby reducing the amount of polymer needed. [0006] The process is proposed for use in various industrial components (e.g., car mirror housings, ink and Laserjet printer parts), no medical applications, procedures, or devices are disclosed. [0007] A CESP process (Controlled Expansion of Saturated Polymers), however, has been contemplated for use in manufacturing implantable polymer structures by Pfannschmidt, et al, “Production of Drug-Releasing Resorbable Polymer Stents with Foam Structure”, Medical Plastics Technology News, Fall 1999-Winter 1999-2000, pp10-12. The focus of the paper is the use of CESP for the incorporation of “thermally sensitive additives.” These additives are suggested to include proteins and growth factors. The devices proposed to deliver these additives are stents. No structural or load-bearing applications are disclosed. In fact, the focus of the invention is the low temperature processability of the invention, however, the resulting process is not readily mass producible. [0008] The CESP may be useful for the delivery of those agents because of the low temperature employed in the CESP process; that is, as previously mentioned, the temperature is not raised to create flow, but rather the pressure is. Therefore, additives may be used that would not survive the temperature of traditional high-temperature molding techniques. However, the CESP process additionally does not adequately address the problem of satisfactory tissue ingrowth or regeneration. [0009] The need for higher strengths in porous polymers has previously been recognized, as in U.S. Pat. No. 6,169,122 (Blizard, et al), where the process is controlled to minimize the cell (i.e., porosity) growth. The aim of the invention is to create homogeneously distributed pores, of a small size (i.e., preferably below 50 microns). To this end, nucleation aids (e.g., talc and titania) are added to the polymer, in an effort to nucleate a larger number of pores during the decompression step (as previously described). However, this paper does not contemplate the problem of satisfactory tissue ingrowth or regeneration, since it strives to create pores that may not be of suitable size to cause effective cellular differentiation and reproduction. [0010] These approaches to utilizing PMF and CESP types of processes for creating porous polymers , for the repair of tissue, would fall short of what is needed in existing surgical procedures. Higher strengths are paramount for implants that may need to withstand any loading following implant; additionally, some implant products (e.g., screws) require continuing strength to withstand the procedural stress. However, proper cell migration into the implant structure, in most cases, require pores on the order of 100 to 250 microns. Therefore, decreasing the pore size below about 100 microns—while increasing strength—could actually prohibit proper cell ingress. [0011] Additionally, talc or titania nucleation aids may not be suited for certain cellular environments, and may further deter cell ingress, or damage or alter normal cellular function and differentiation if such cells were to infiltrate the implant. [0012] The PMF and CESP processes, as disclosed above, creates pores that typically do not communicate with each other. This isolation slows and potentially prevents the continued ingress of cells, through the entire implant cross section, which may delay tissue development, and/or restrict tissue development to the regions at or near the surface of the implant. [0013] Additionally, the closed cell pores of the PMF process do not address the concerns of heterogeneous degradation that occur in massive biodegradable implants. Hydrolysis is not an erosion phenomenon for most biodegradable polymers, but is, instead, a bulk process with random hydrolytic scission of covalent ester bonds. The correlation of in vivo and in vitro rates of hydrolysis has led to the theory that degradation is not facilitated by enzymatic catalysis, or at least not during the initial loss of molecular weight. Hydrolysis is affected by many factors including crystallinity, molecular weight, polydispersity, sterilization process, geometry of the device, total surface area exposed to interstitial fluid, sight of implantation, etc. Although many functions affect biodegradation, hydrolysis has generally been identified to proceed in four main steps i.e., hydration, strength loss, structural integrity loss, and mass loss. [0014] The closed cell pores of the PMF and CESP processes may exasperate problems associated with heterogeneous degradation by providing multiple isolated chambers separated by a thin membrane. These thin membranes may expedite the movement of body fluids deep into the implant where they may pool for a prolonged period of time isolated from interstitial turnover. [0015] In addition, the pores produced by these, and similar, processes typically have uniform or smooth surfaces between the matrix juncture (similar to that of honeycomb structures). Even if these processes were able to yield pores with open architectures, the smooth walls would not be conducive to cell attachment. [0016] Accordingly, there exists a need for homogenous, mass-producible, higher strength, resorbable implants with large pores. The pores may be modeled (i.e., the surfaces made rough or irregular) or intercommunicating and/or foster cell attachment. Embodiments of the current invention address these and other shortcomings in the prior art. SUMMARY OF THE INVENTION [0017] The present invention provides a resorbable porous structure for healing tissue defects comprising a porous polymer body produced from a process utilizing an SCF but without, in a preferred embodiment, any nucleating aids or fillers. [0018] In yet another embodiment, the present invention relates to an improved porous implant wherein the pores of the implant present a modeling material or agent on their surfaces. This “second” material provides a textured or roughened face to the internal surfaces of pores. Additionally, this second material can be incorporated in sufficient quantity to, among other things, create a microporous network connecting interior closed cell pores with each other as well as the exterior of the device. [0019] In yet another embodiment, the structure is reinforced with a strengthening agent, as will be discussed later. [0020] Certain polymers are very thermally sensitive and extended residence time within melt processing equipment (e.g., PMF equipment) can lead to extensive molecular weight degradation. Other polymers have very narrow processing windows where on the high end of a narrow range the polymer burns and on the low end of the range the polymer does not flow effectively and high stress conditions are created in the final part. By using a gas or solvent to plasticize the polymer, processing temperatures, pressures and time can be reduced. For example, when processing resorbable polymers (e.g. polylactide, polyglycolide, polycaprolactone, etc.), this reduction in processing temperature, pressure and time can help to preserve the molecular weight of the final product. By using described processes for this invention, these polymers can be used for creating large low-stress mass-produced resorbable medical devices. [0021] PMF and PSPC (Phase Separation Polymer Concentration) (as described later) processes may appear complex and varied but in actuality produce similar results. It is recognized that there exists other processes that are known in the art, which also produce analogous systems and results These alternate processes are incorporated herein, to the extent practicable. [0022] In the PMF process, the nucleating agent, if any, can be mixed into a gas permeated plasticized polymer. The gas (e.g. air, oxygen, carbon dioxide, nitrogen, argon, or any inert gas, including combinations thereof) trapped within the polymer begins to expand as the pressure external to the polymer is reduced. As the gas expands it attempts to create uniformly dispersed homogeneous spherical pores. The growth of the pores is disrupted as the walls defining the pores thin to the point that the nucleating agent begins to protrude and therefore the nucleating agent may act as a “modeling agent”. As the gas continues to expand the modeling agent particles begin to interfere with each other and/or the expanding pore walls, and force the pore to take on an irregular shape. [0023] In the PSPC process, the modeling agent is dispersed within a polymer solvent solution. The temperature of the mixture is lowered until crystals form within the solution. As the crystals grow they force the polymer into a smaller and smaller area similar to the expanding gas in the PMF process. The growth of the crystals is disrupted as they come in contact with the modeling agent. As the crystals continue to grow they press the modeling agent particles in contact with each other and are thus forced to grow around the particles in an irregular fashion. After solidification vacuum or leaching, a chilled non-solvent removes the solvent crystals. [0024] By varying the ratio of polymer to modeling agent in the PMF and PSPC processes, the porosity, pore surface texture and geometry of the matrix may be controlled; wherein matrix is polymer, molding agent and porosity combined. Low polymer constituent concentrations combined with longer processing times allows the growth of large pores, thereby affecting mechanical and physical properties. The rate at which the pores grow (via gas expansion or crystal growth, as appropriate) can determine where in the polymer mass the modeling agent is located. Slow growth of pores allows the modeling agent to migrate within the thinning polymer walls and remain covered or encapsulated [see (FIGS. 8 - 10 ). Rapid expansion of the pores does not allow sufficient time for the modeling agent to migrate within the walls resulting in partial exposures of the modeling agent (see FIGS. 11 - 13 ). The modeling agent may also control physical and biologic properties, as will be described later. Examples of polymers useful for current invention are listed in Table 1. TABLE 1 Examples and Subtypes of Bioresorbable Polymers for Construction of the Device of the Current Invention: Alginate Aliphatic polyesters Bioglass Cellulose Chitin Collagen Types 1 to 20 Native fibrous Soluble Reconstituted fibrous Recombinant derived Copolymers of glycolide Copolymers of lactide Elastin Fibrin Glycolide/l-lactide copolymers (PGA/PLLA) Glycolide/trimethylene carbonate copolymers (PGA/TMC) Polylactides (PLA) Glycosaminoglycans Hydrogel Lactide/tetramethylglycolide copolymers Lactide/trimethylene carbonate copolymers Lactide/ε-caprolactone copolymers Lactide/σ-valerolactone copolymers L-lactide/dl-lactide copolymers Methyl methacrylate-N-vinyl pyrrolidone copolymers Modified proteins Nylon-2 PHBA/γ-hydroxyvalerate copolymers (PHBA/HVA) PLA/polyethylene oxide copolymers PLA-polyethylene oxide (PELA) Poly (amino acids) Poly (trimethylene carbonates) Poly hydroxyalkanoate polymers (PHA) Poly (alklyene oxalates) Poly (butylene diglycolate) Poly (hydroxy butyrate) (PHB) Poly (n-vinyl pyrrolidone) Poly (ortho esters) Polyalkyl-2-cyanoacrylates Polyanhydrides Polycyanoacrylates Polydepsipeptides Polydihydropyrans Poly-dl-lactide (PDLLA) Polyesteramides Polyesters of oxalic acid Polyglycolide (PGA) Polyiminocarbonates Polylactides (PLA) Poly-l-lactide (PLLA) Polyorthoesters Poly-p-dioxanone (PDO) Polypeptides Polyphosphazenes Polysaccharides Polyurethanes (PU) Polyvinyl alcohol (PVA) Poly-β-hydroxypropionate (PHPA) Poly-β-hydroxybutyrate (PBA) Poly-σ-valerolactone Poly-β-alkanoic acids Poly-β-malic acid (PMLA) Poly-ε-caprolactone (PCL) Pseudo-Poly (Amino Acids) Starch Trimethylene carbonate (TMC) Tyrosine based polymers [0025] In certain embodiments, the nucleating agent (or modeling agent) may be left out of the processing mix to allow the pores to grow (e.g. since fewer pores are nucleated they may grow larger). Pores in the range of about 50-500 microns may be used in an implant, but may preferably be about 100-300 microns. It is realized that there may be a strength trade-off with this approach. [0026] The modeling agent may also be composed of one or more materials that may have the ability to react with each other to create additional substances within the porosity of the invention. For example, Chitosan and sodium hyaluronate powders can be blended into the polymer and chemically linked to each other within the pores of the invention. This is accomplished by rapid expansion of the pores resulting in exposure of the two modeling agents after which the pores are flooded with a pH-adjusted fluid. The pH-adjusted fluid dissolves the modeling agents within the pores creating a polyelectrolytic system. Within this system chitosan and hylauronate become bound to each other and precipitate out of solution as an insoluble hydrogel. [0027] The incorporation of high modulus strengthening components (e.g., polymers, ceramics or metallics) as the modeling agent will affect the strength and toughness of the resulting structure. The strengthening agent may be in various forms (e.g., particulate, fiber or whisker). The incorporation of these strengthening components improves the strength, such that the pore size may be increased to allow inward cell migration, while retaining or improving the mechanical properties (when compared with a small pore implant without a strengthening component). Additionally, the same modeling agent used to affect the physical properties of the implant can also affect its biologic properties. Hydroxyapatite would not only improve the strength of the implant, but also be capable of, for example, extracting endogenous growth factors from the host tissue bed while functioning as a microporous conduit facilitating movement of interstitial fluid throughout the isolated porosities of the device. Examples of materials useful as modeling agents are listed in Table 2. TABLE 2 Examples of Materials that may be Utilized as Modeling Agents of the Current Invention: Alginate Bone allograft or autograft Bone Chips Calcium Calcium Phosphate Calcium Sulfate Ceramics Chitosan Cyanoacrylate Collagen Dacron Demineralized bone Elastin Fibrin Gelatin Glass Gold Glycosaminoglycans Hydrogels Hydroxy apatite Hydroxyethyl methacrylate Hyaluronic Acid Liposomes Mesenchymal cells Microspheres Natural Polymers Nitinol Osteoblasts Oxidized regenerated cellulose Phosphate glasses Polyethylene glycol Polyester Polysaccharides Polyvinyl alcohol Platelets, blood cells Radiopacifiers Salts Silicone Silk Steel (e.g. Stainless Steel) Synthetic polymers Thrombin Titanium Tricalcium phosphate [0028] The modeling agent can serve multiple purposes which may include but are not limited to: [0029] 1. creating a textured surface on the internal surfaces defining the pores; [0030] 2. creating a microporous conduit system between pores; [0031] 3. reaction-extraction of endogenous growth factors; [0032] 4. carrying and/or delivering drugs, biologically active or therapeutic agents; [0033] 5. function as a drug, biologically active or therapeutic agent; [0034] 6. modifying mechanical properties (e.g. strength, flexibility, etc); [0035] 7. function as an in-vivo leachate to increase the overall porosity. [0036] The irregular pore surfaces formed by the modeling agent serves multiple purposes which may include but are not limited to: [0037] 1. increased surface area provides greater numbers of anchorage points for cell attachment; [0038] 2. increased surface area permits modification to the leaching rate of drugs or other therapeutics; [0039] 3. textured surfaces increase quantity of material that can be coated on the interior pore surfaces; [0040] 4. irregular surfaces increase the resistance to flow through the implant. [0041] 5. engineered surfaces can affect how cells attach, thereby modifying the resulting tissue that is generated. [0042] 6. engineered or roughened surfaces can alter the overall pore geometry, which can affect stresses on differentiating cells, thereby dictating cell differentiation modalities. [0043] Additional materials may also be used at the time of manufacture to control the process output (e.g. plastisizers, surfactants, dyes, etc.) For example, processing the polymer with stearic agents will cause the thinning of matrix between the pores, which is most easily penetrable, or rapidly resorbing, following implantation. This will result in a device with high strength, and interconnected pores, which will afford easier migration of cells through the implant. [0044] In yet another embodiment, the polymer and modeling agent, as well as the pores, once formed, can be invested with drugs or other biologically active or therapeutic agents including cells and cellular components (together “therapy”) for rapid or slow delivery, as will be discussed. Additionally, microspheres may be incorporated for an additional mode of therapy delivery, as will be discussed. The methods of therapy delivery contemplated by the various embodiments of the current invention include: delivery from the polymer constituent, delivery from the pores, delivery from the modeling agent, and/or delivery via microspheres, including any combination of the preceding modalities. These therapies may treat any underlying condition, which necessitated the implant or procedure, and/or the therapy may treat or support the ingrowing or regenerated tissue. Examples of materials that can be incorporated into and/or delivered by the implant are listed in Table 3. TABLE 3 Examples with Some Sub-types of Biological, Pharmaceutical, and other Therapies that can be Incorporated into and/or Delivered via the Device in Accordance with the Present Invention Cellular Material Deliverable via this Invention Adipose cells Blood cells Bone marrow Cells with altered receptors or binding sites Endothelial Cells Epithelial cells Fibroblasts Genetically altered cells Glycoproteins Growth factors Lipids Liposomes Macrophages Mesenchymal stem cells Progenitor cells Reticulocytes Skeletal muscle cells Smooth muscle cells Stem cells Vesicles Some Sub-types of Biological, Pharmaceutical, and other Therapies Adenovirus with or without genetic material Angiogenic agents Angiotensin Converting Enzyme Inhibitors (ACE inhibitors) Angiotensin II antagonists Anti-angiogenic agents Antiarrhythmics Anti-bacterial agents Antibiotics Erythromycin Penicillin Anti-coagulants Heparin Anti-growth factors Anti-inflammatory agents Dexamethasone Aspirin Hydrocortisone Antioxidants Anti-platelet agents Forskolin Anti-proliferation agents Anti-rejection agents Rapamycin Anti-restenosis agents Antisense Anti-thrombogenic agents Argatroban Hirudin GP IIb/IIIa inhibitors Anti-virus drugs Arteriogenesis agents acidic fibroblast growth factor (aFGF) angiogenin angiotropin basic fibroblast growth factor (bFGF) Bone morphogenic proteins (BMP) epidermal growth factor (EGF) fibrin granulocyte-macrophage colony stimulating factor (GM-CSF) hepatocyte growth factor (HCF) HIF-1 Indian hedgehog (Inh) insulin growth factor-1 (IGF-1) interleukin-8 (IL-8) MAC-1 nicotinamide platelet-derived endothelial cell growth factor (PD-ECGF) platelet-derived growth factor (PDGF) transforming growth factors alpha & beta (TGF-.alpha., TGF-beta.) tumor necrosis factor alpha (TNF-.alpha.) vascular endothelial growth factor (VEGF) vascular permeability factor (VPF) Bacteria Beta blocker Blood clotting factor Bone morphogenic proteins (BMP) Calcium channel blockers Carcinogens Cells Stem cells Bone Marrow Blood cells Fat Cells Muscle Cells Umbilical cord cells Chemotherapeutic agents Ceramide Taxol Cisplatin Paclitaxel Cholesterol reducers Chondroitin Clopidegrel (e.g., plavix) Collagen Inhibitors Colony stimulating factors Coumadin Cytokines prostaglandins Dentin Etretinate Genetic material Glucosamine Glycosaminoglycans GP IIb/IIIa inhibitors L-703,081 Granulocyte-macrophage colony stimulating factor (GM-CSF) Growth factor antagonists or inhibitors Growth factors Autologous Growth Factors B-cell Activating Factor (BAFF) Bovine derived cytokines Cartilage Derived Growth Factor (CDGF) Endothelial Cell Growth Factor (ECGF) Epidermal growth factor (EGF) Fibroblast Growth Factors (FGF) Hepatocyte growth factor (HGF) Insulin-like Growth Factors (e.g. IGF-I) Nerve growth factor (NGF) Platelet Derived Growth Factor (PDGF) Recombinant NGF (rhNGF) Tissue necrosis factor (TNF) Tissue derived cytokines Transforming growth factors alpha (TGF-alpha) Transforming growth factors beta (TGF-beta) Vascular Endothelial Growth Factor (VEGF) Vascular permeability factor (UPF) Acidic fibroblast growth factor (aFGF) Basic fibroblast growth factor (bFGF) Epidermal growth factor (EGF) Hepatocyte growth factor (HGF) Insulin growth factor-1 (IGF-1) Platelet-derived endothelial cell growth factor (PD-ECGF) Tumor necrosis factor alpha (TNF-.alpha.) Growth hormones Heparin sulfate proteoglycan HMC-CoA reductase inhibitors (statins) Hormones Erythropoietin Immoxidal Immunosuppressant agents inflammatory mediator Insulin Interleukins Interlukins Interlukin-8 (IL-8) Lipid lowering agents Lipo-proteins Low-molecular weight heparin Lymphocites Lysine MAC-1 Morphogens Bone morphogenic proteins (BMPs) Nitric oxide (NO) Nucleotides Peptides PR39 Proteins Prostaglandins Proteoglycans Perlecan Radioactive materials Iodine-125 Iodine-131 Iridium-192 Palladium 103 Radio-pharmaceuticals Secondary Messengers Ceramide Signal Transduction Factors Signaling Proteins Somatomedins Statins Stem Cells Steroids Thrombin Sulfonyl Thrombin inhibitor Thrombolytics Ticlid Tyrosine kinase Inhibitors ST638 AG-17 Vasodilator Histamine Forskolin Nitroglycerin Vitamins E C Yeast [0045] The resulting embodiments of this invention will be useful in the improved repair and regeneration of various soft tissue (e.g. tendon, muscle, skin) and hard tissue (e.g. bone, cartilage) types. Furthermore, it is contemplated that organs or sections thereof (e.g., liver, a heart valve, etc., see Table 4) may also be re-grown or regenerated with implants incorporating the technology of this invention. TABLE 4 Examples of tissues and procedures potentially benefiting from the present invention Ankle reconstruction Artery Biopsy Bone Bone biopsy Bone tissue harvest Burn treatment Bypass surgery Cardiac catheterization Cartilage Compression fractures Cosmetic Surgery Dental Dura Elbow reconstruction Foot reconstruction Gall bladder Hand reconstruction Heart Heart valve replacement Hip reconstruction/replacement Kidney Knee reconstruction/replacement Ligament Liver Long bone fixation Lung Maxillofacial reconstruction/repair Meniscus Mosaicplasty Muscle Nerves Osteotomy Pancreas Ridge augmentation Shoulder reconstruction Skin Spinal arthrodesis Spinal fixation/fusion Tendon Third molar extraction Topical wound Trauma repair Wrist reconstruction [0046] Suitable materials, and additives, for the polymer constituent of these various embodiments includes, but is not limited to, those listed in the above referenced tables. Various resorbable polymers are contemplated by this invention, but components or constituents may also be made of non-resorbable materials, as well. In this regard, In these various embodiments, as well as the balance of the specification and claims, the term “resorbable” is frequently used. There exists some discussion among those skilled in the art, as to the precise meaning and function of resorbable materials (e.g., polymers, ceramics), and how they differ from bioabsorbable, absorbable, bioresorbable, biodegradable, and bioerodable materials. The current disclosure contemplates all of these materials, modalities, or mechanisms, and considers them as equivalent with regard to the function of the current embodiments, even though these processes may be proved to differ significantly in practice, as they are similar in objective and result. BRIEF DESCRIPTION OF THE DRAWINGS [0047] [0047]FIG. 1 shows the process by which pores having a textured surface grow into irregular shapes. The drawings focus in on 3 time points in a dynamic process (FIGS. 1 A-B, 1 C-D, 1 E-F). FIG. 1A shows the genesis of pores 110 in the polymer 100 filled with a modeling agent 120 . The pores 110 are the result of expanding gas, vapors, or crystals. FIG. 1B fills in the polymer and modeling agent with a solid black color 190 so that the shape and orientation of the pores 110 can be easily identified. FIG. 1C show the expanding pores 150 coming in contact with modeling agent 140 while pushing polymer 130 out of the way. [0048] [0048]FIG. 1D fills in the polymer and modeling agent with a solid black color 190 so that the texturing of the pores 150 can be easily identified. In FIG. 1E, the modeling agent particles 170 has been pushed together by the further expanding pores 180 . As the modeling agent particles 170 interfere with each other the pores 180 are forced into irregular shapes. The polymer 160 separating the pores has now been squeezed into thin partitions. [0049] [0049]FIGS. 2 and 3 are Scanning Electron Microscope (SEM) images of porous polymer constructs not using a modeling agent, showing a smooth flowing surface, and regularly shaped pores. [0050] [0050]FIG. 4 shows a SEM image of a porous polymer construct using an insufficient quantity of particulate to be classified as a modeling agent. showing smooth flowing surfaces and regularly shaped pores. [0051] [0051]FIG. 5 demonstrates a construct containing approximately the minimal amount of particulate to be considered a modeling agent. Notice the textures surface and weakly irregular pore structure. [0052] [0052]FIGS. 6 and 7 demonstrate constructs containing sufficient quantities of particulate material to be classified as, and have the desired effect of, modeling agents. Notice the highly textured surfaces and large irregular pores resulting from the modeling agents presence. [0053] FIGS. 8 - 10 show constructs demonstrating the use of microspheres as a modeling agent to create irregular pores with a textured surface wherein the modeling agent is embedded into and covered by the polymer. [0054] FIGS. 11 - 13 show constructs demonstrating the use of microspheres as a modeling agent to create irregular pores with a textured surface wherein the modeling agent is held on the surfaces of the pore walls. [0055] [0055]FIG. 14 shows a cross-section of a bone screw, as an example of an application of such a product created by this process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0056] An ideal tissue repair/treatment/prosthetic device should possess various of the following properties: (1) it should be chemically biocompatable; (2) it should be partially if not completely resorbable so that the patient's own tissue ultimately replaces at least a portion of the device; (3) it should be porous to allow the infiltration of cells over time; (4) the porosity should provide it with a high surface area to mass ratio for cell attachment and delivery of therapeutics; (5) despite the porosity, it should provide a high degree of structural integrity in order to support, fixate, or treat surrounding tissues until the patient's own bone/tissue heals; (6) the device should have the ability to incorporate additives used to enhance the mechanical or biochemical performance of the device (e.g. strengthening agents, cells, drugs, biomolecules, other agents); and, (7) the device should be mass manufacturable to be able to provide the product at a reasonable price to the consumer. The various embodiments of the current invention address these properties. [0057] The basic PMF process entails four general steps: 1) gas dissolution, 2) nucleation, 3) cell growth, and 4) shaping. During gas dissolution, a blowing agent or supercritical fluid (e.g., CO 2 or N 2 ) is injected into molten polymer (together the “chamber material”), in a pressurized process chamber. During nucleation, the gas, which is in solution within the polymer melt, comes out of solution to form a suspension of bubbles within the melt (i.e., acts as a “pore induction fluid”). This occurs as a result of a change in the conditions that affect the solubility of the gas within the polymer melt. For example, a rapid pressure drop or temperature change would affect gas solubility. In some instances, a nucleating agent such as talc is added to the chamber material to promote the formation of a nucleation site. As such, the processing conditions and the presence of a nucleating agent can affect, and therefore lead to control of, the cell growth. The shaping of the final part is controlled by the mold or by some type of final post processing (e.g. machining). [0058] In a preferred embodiment, the improved process of the current invention entails the combining of a system for delivering controlled gas dispersion with a system for producing the porous component in its final form. The component may be produced by one of several methods traditionally used in the manufacture of plastic products. These include injection molding, extrusion, and blow molding. [0059] The gas delivery unit provides a high pressure, accurately metered flow of gas that has reached a stage of Supercritical Flow (SCF). This gas in its SCF state is then delivered to the plastic process equipment at a point in the melt flow of the plastic material that has been determined to produce a final molded or extruded component with an optimized degree of porosity. The addition of a modeling material (as previously described), at this stage or earlier, may result in the formation of irregular pores with a textured surface. [0060] In various of these embodiments, the optimization of this system includes the balancing of three conditions: 1. The gas blowing agent chosen may be introduced in amounts higher than conventionally used in foaming applications and must be completely dissolved in the polymer before pressure is lowered; 2. The blowing agent or SCF gas stays in solution in the melt flow by maintaining a consistent pressure profile; 3. There must be a high rate of change of solubility versus pressure. [0061] The gas delivery system must introduce the proper amount of SCF gas into the melt flow in the plasticising unit of the injection molding or extrusion equipment to create the desired effect on the melt flow. This gas must be introduced at a pressure that is higher than pressure existing in the plasticising unit. In a preferred embodiment, the chamber material may be heated to improve flowablility or to tailor the resulting porosity. Heat may be supplied to the chamber material while it is under pressure in the chamber and/or while it is being expanded in the mold. [0062] Both injection molding and extrusion or blow molding applications of the PMF system should require customization of a standard plasticizing unit to allow creation of a homogeneous and single-phase polymer melt solution, which, in a preferred embodiment, contains a modeling agent. Changes to tooling may be required to optimize production of specific components. In addition, the software that controls machine cycle functions of an injection molding or other processing system may need to be modified. [0063] In yet another embodiment, the process includes subjecting the polymer and any modeling agent to solvent vapors under high pressure. The solvent vapors penetrate and plasticize the polymer without the addition of high heat. The polymer is then rapidly subjected to reduced pressure thereby boiling off the solvent vapors, expanding the polymer and leaving behind a porous structure. Solvents with low boiling points are favorable in this process (e.g. acetone, tetrahydrofuran, etc.) [0064] In yet another embodiment, the modeling agent is dispersed within a polymer solvent solution. The temperature of the mixture is lowered until crystals form within the solution. As the crystals grow they force the polymer into a smaller and smaller area similar to the expanding gas in the PMF process. The growth of the crystals is disrupted as they come in contact with the modeling agent. As the crystals continue to grow they press the modeling agent particles in contact with each other and are thus forced to grow around the particles in an irregular fashion. After solidification vacuum drying or leaching in a chilled non-solvent removes the solvent crystals. [0065] In addition to catalyzing the formation of irregular shaped pores with a textured surface, a preferred embodiment uses the modeling agent as a strengthening component. The strengthening components are added to the matrix, thereby increasing strength and/or toughness. These strengthening components may be polymers, resorbable or non-resorbable, which may be suitable for primary matrix components themselves (but vary in a mechanical or physical property from the primary polymer); or the strengthening component may be non-polymeric (e.g., ceramic). [0066] There are numerous ceramic systems that display both biocompatability and degradability. One application of devices made with the process of this invention is devices for repair of bone. In the body, the bone itself is the natural storehouse of minerals. The major mineral component of bone is hydroxyapatite, a form of calcium phosphate. Other calcium phosphate salts in bone include monotite, brushite, calcium pyrophosphate, tricalcium phosphate, octocalcium phosphate, and amorphous calcium phosphate. Additionally, bone contains calcium carbonates. Hydroxyapatites and tricalcium phosphates are the most widely studied of the calcium phosphates, which have calcium to phosphate ratios of between 1.5 and 1.67, respectively. Calcium phosphate, Ca 10 (PO 4 ) 6 (OH) 2 , is known as a physiologically acceptable biomaterial which is useful as a hard tissue prosthetic. Another calcium mineral used as a bone replacement material is calcium sulfate. Each of these materials either alone or in combination with other materials would serve as suitable strengthening agents. In addition, it is recognized that other osteoinductive, osteoconductive, and inert materials may be suitable for the strengthening agent of the present invention. [0067] Alternatively, strengthening agents may comprise fibers, whiskers, platelets or other oriented additions. These agents also may be resorbable, non-resorbable, or even non-polymeric in composition. [0068] [0068]FIG. 14 shows a cross-section of an implantable screw (e.g. a bone screw) which may be manufactured by the current invention. The typical screw 200 comprises a body 210 with threads 220 or other attachment or securement means (e.g. barbs, etc.), not shown. The screw may have a geometry to accommodate an insertion device, for example a slot 230 or a hexagonal indentation, etc. (not shown) such screw may have a pointed or semi-pointed end 240 , or it may be blunt (not shown). Various other fixation and reconstructive devices are contemplated by this invention, including but not limited to fixation plates, rods, pins, rivets, anchors, cages, brackets, etc. [0069] The methods of therapy delivery contemplated by the various embodiments of the current invention include: delivery from the polymer constituent, delivery from the pores, delivery from the modeling agent, delivery from a coating, and/or delivery via microspheres, including any combination of the preceding modalities. [0070] Polymer constituent therapy delivery may be through various mechanisms, including but not limited to, therapy incorporated into the polymer constituent by physical entrapment or by conjugation of the therapy with the monomer or polymer. [0071] Therapy delivery may come from the pores, as release from physical entrapment of the therapy from an enclosed pore, it may come from material adsorbed or loosely adhering to the surface of enclosed or interconnected pores, or it may stay suspended within the pores of the implant awaiting contact with cells entering the pores. [0072] It is recognized that each of the delivery modes could result in different delivery rates. That is, therapy may evolve more rapidly from interconnected pores, than from isolated pores, which may in-turn release therapy faster than any therapy delivered by the polymer constituent (i.e., as it degrades). [0073] In one embodiment the therapy is co-mingled with the various other constituents and components prior to the processing. This allows for some concentration of the therapy to remain in the polymer constituent, while some of the same therapy migrates or precipitates into the porous region of the matrix. An equilibrium phase diagram for the components and constituents would allow the tailoring of the concentration of therapy in each region (i.e., pore or polymer constituent), additionally, therapies with low solubility in either component will aid preferential placement of therapy. Therapy composition, PMF process pressure-temperature parameters, and time, among other variables, will affect the final location and concentration of the therapy. [0074] Addition of a secondary therapy, or other active or inactive agent, may alter the solubility of a primary therapy in either region, thereby altering primary therapy placement. [0075] Alternatively, a secondary therapy may be added because of its complementary therapeutic effect, or because of its preference to precipitate in an alternate region of the matrix (compared with the primary therapy). Any plurality of therapies are deliverable by these techniques. [0076] The therapies may be of various states (i.e., solid, liquid, gas, plasma, etc.), prior to introduction, into the pore forming process; this may affect their ultimate solubility, and it is recognized that the therapy state in the finished matrix may not be the same as what was added. [0077] In some instances it may be beneficial to utilize multiple gases with the polymer processing system. For example, each specific gas could be utilized to carry one or more therapies. The incorporation of the gas into the polymer solution could be customized to optimize the delivery of the therapy. Multiple gases could also be used to create a multi-phasic system of cell sizes and distribution within the final device. [0078] The subject invention can also incorporate cellular additions. Cellular material may be delivered in combination with, or independent of drug delivery. The cellular material may be present on the inside of the implant, outside of the implant, or incorporated within the implant in a porous construct, or other such embodiment. The cellular material may be added to the implant immediately prior to insertion into the body of the living being or may be grown on the implant in the days or weeks prior to implantation so more mature cells are in place when the device is implanted. If the cells are seeded on the implant several days or weeks prior to implantation, the implant may be placed in an in-vitro setup that simulates the in-vivo environment (e.g., where blood or a blood substitute medium is circulated at appropriate pressure and temperature) to acclimate the cells to the host environment. The cell-seeded implant may be incubated in this in-vitro setup at physiologic conditions for several days prior to implantation within the body. Cell seeding techniques have been developed for a variety of cell types. Examples of cellular material that may be seeded on implant include those listed in Table 3. [0079] It is also conceived that a source of cytokines or growth factors (e.g. platelet-rich plasma, bone marrow cells, etc.), whether synthetic, autologous or allograft in origination, can be delivered with the devices of this invention (e.g. incorporated into the implant or delivered via the delivery system). For example, it is known that one of the first growth factors to initiate the cascade leading to bone regeneration are platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-β). Each of these growth factors is derived from the degranulation of platelets at the wound, defect or trauma site. It is believed that increasing the presence of such platelets at the wound or trauma site can increase the rate of healing and proliferation needed to regenerate bone. [0080] The application of platelet-rich plasma (PRP) or other autologous blood components is one way to deliver a highly concentrated dose of autologous platelets. PRP is easily prepared by extracting a small amount of the patient's blood and processing it, for example using gradient density centrifugation, to sequester and concentrate the patient's platelet derived growth factors. [0081] Bone marrow may also be added to the present invention to aid in healing and repair. [0082] It is further contemplated that gene therapy may be delivered via the various embodiments of this device. Gene therapies are currently of two primary types, and are both together hereinafter referred to as “gene therapy” or “engineered cells”, however others are anticipated; the primary methodologies and basic understandings are described herein (see also table 3). [0083] First, nucleic acids may be used to alter the metabolic functioning of cells, without altering the cell's genome. This technique does not alter the genomic expressions, but rather the- cellular metabolic function or rate of expression (e.g., protein synthesis). [0084] Second, gene expression within the host cell may be altered by the delivery of signal transudation pathway molecules. [0085] In a preferred embodiment, mesenchymal stem cells are harvested from the patient, and infected with vectors; currently, preferred vectors include phages or viri (e.g., retrovirus or adenovirus). This preferred infection will result in a genetically engineered cell, which may be engineered to produce a growth factor (e.g., insulin like growth factor (IGF-1)) or a morphogen (e.g., bone morphogenic protein (BMP-7)), etc. (see also those listed in Table 3). Methods of infection as well as specific vectors are well known to those skilled in the art, and additional ones are anticipated. Following this procedure, the genetically engineered cells are loaded into the implant. Cytokines as described and used herein are considered to include growth factors. [0086] Loading of the cells in this embodiment may be achieved prior to processing, during, or immediately following the implantation procedure. Loading may be achieved by various methods including, but not limited to, the injection of a solution containing said engineered cells into the implant, by combining said cells with said matrix components prior to fabrication, or following fabrication or implant. [0087] The term “microsphere” is used herein to indicate a small additive that is about one to three orders of magnitude smaller (as an approximate relative size) than the implant. The term does not denote any particular shape, it is recognized that perfect spheres are not easily produced. In addition to true spheres, the present invention contemplates elongated spheres and irregularly shaped bodies. “Nanosphere” is used herein to denote particles, whether spherical or irregular, that are several orders of magnitude smaller than microspheres. [0088] Microspheres can be made of a variety of materials such as polymers, silicone and metals. Biodegradable polymers are ideal for use in creating microspheres for use in these embodiments (e.g., see those listed in Table 1). The release of agents from bioresorbable microparticles is dependent upon diffusion through the microsphere polymer, polymer degradation and the microsphere structure. Although most any biocompatible polymer could be adapted for this invention, the preferred material would exhibit in vivo degradation. It is well known that there can be different mechanisms involved in implant degradation like hydrolysis, enzyme-mediated degradation and bulk or surface erosion. These mechanisms can alone or combined influence the host response by determining the amount and character of the degradation product that is released from the implant. The most predominant mechanism of in vivo degradation of synthetic biomedical polymers like polyesters and polyamides is generally considered to be hydrolysis, resulting in ester bond scission and chain disruption. In the extracellular fluids of the living tissue, the accessibility of water to the hydrolysable chemical bonds makes hydrophilic polymers (i.e. polymers that take up significant amounts of water) susceptible to hydrolytic cleavage or bulk erosion. Several variables can influence the mechanism and kinetics of polymer degradation. Material properties like crystallinity, molecular weight, additives, polymer surface morphology, and environmental conditions. As such, to the extent that each of these characteristics can be adjusted or modified, the performance of this invention can be altered. [0089] In a homogeneous embodiment (i.e., monolithic or composite of uniform heterogeneity) of a therapy delivering implant material, the device provides continuous release of the therapy over all or some of the degradation period of the device. In an embodiment incorporating microspheres, the therapy is released at a preferential rate independent of the rate of degradation of the matrix resorption or degradation. In certain applications it may also be necessary to provide a burst release or a delayed release of the active agent. The device may also be designed to deliver more than one agent at differing intervals and dosages, this time-staged delivery also allows for a dwell of non-delivery (i.e., a portion not containing any therapy), thereby allowing alternating delivery of non-compatible therapies. Delivery rates may be affected by the amount of therapeutic material, relative to the amount of resorbing structure, or the rate of the resorption of the structure. [0090] Time-staged delivery may be accomplished via microspheres, in a number of different ways. The concentration of therapeutic agent may vary radially, that is, there may be areas with less agent, or there may be areas with no agent. Additionally, the agent could be varied radially, such that one therapy is delivered prior to a second therapy—this would allow the delivery of non-compatible agents, with the same type of sphere, during the same implant procedure. The spheres could also vary in composition among the spheres, that is, some portion of the sphere population could contain one agent, while the balance may contain one or more alternate agents. These differing spheres may have different delivery rates. Finally, as in the preceding example, there could be different delivery rates, but the agent could be the same, thereby allowing a burst dose followed by a slower maintained dose. [0091] Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Devices and processes (e.g., improved Plasticized Melt Flow processes (PMF) or improved Phase Separation Polymer Concentration (PSPC), etc.) used to make resorbable and non-resorbable structures for treating and/or healing of tissue defects are disclosed. Among the advantages of using these improved processes are the preservation of molecular weight and the broadening of the processing conditions for temperature sensitive polymers and therapies (e.g. polylactide, polyglycolide, polycaprolactone or Cisplatin, etc.). This reduction in processing temperature, pressure and time can help to preserve the molecular weight and/or integrity of the final product or any additive incorporated therein. Additionally, pore size and shape tailoring can increase the osteoconductive nature of the device.

FIELD OF THE INVENTION The present invention relates generally to pupilometry systems and, more particularly, to pupilometry systems having a pupil irregularity detection capability. In one particularly innovative aspect, the present invention relates to hand-held pupilometry systems having a pupil irregularity detection capability, to methods and processing sequences used within such systems, and to methods of using such systems. In another innovative aspect, the present invention relates to a medical diagnostics system incorporating a pupilometer and medical database for correlating actual or derived pupilary image analysis data with stored medical data to formulate medical diagnoses, and to methods of implementing and utilizing such a diagnostics system. BACKGROUND OF THE INVENTION Systems for monitoring pupil size and pupil responsiveness characteristics are well known in the art and are generally referred to as pupilometry systems or, simply, pupilometers. One early pupilometer is described in U.S. Pat. No. 3,533,683, which issued to Stark et al. on Oct. 13, 1970 and is entitled "Dynamic Pupilometers Using Television Camera System." The Stark et al. system employed a television camera system, a digital computer system, an infrared light source, and a visual light stimulator for determining the instantaneous size of a pupil as an eye (or neurologic pupilary control system) of a patient was exposed to various stimuli. Like the early Stark et al. system, conventional pupilometers measure, for example, the diameter of a pupil before and after the pupil is exposed to a light stimulus pulse and also measure the rates at which the pupil may constrict and dilate in response to the initiation and termination of the light stimulus pulse. Pupilometers may comprise hand-held units or, alternatively, may comprise desk or table-mounted, stand-alone units. Pupilometers also generally include some mechanism for ensuring that an imager within the pupilometer is properly positioned in relation to a pupil to be imaged. For example, U.S. Pat. No. 5,646,709, issued to Elbert P. Carter, describes an electronic centering system for ensuring that a pupilometer is properly positioned in relation to a pupil to be imaged. Similarly, U.S. Pat. No. 5,187,506, issued to Elbert P. Carter, describes an eye orbit housing for ensuring proper positioning between a pupilometer and an eye of a subject prior to the initiation of a pupilary scanning procedure. Those skilled in the art will appreciate, however, that for a pupilometer to have maximum utility maximum flexibility should be provided for positioning the imager. For example, in the case of a hand-held system few, if any, restrictions should be placed upon the orientation of the imager prior to enabling an imaging function. The reason for this is that medical personnel at, for example, an accident site may have difficulty in positioning an imager in a prescribed position for acquiring pupilary response data. Thus, it is believed that, for hand-held units in particular, a need exists within the pupilometer field for improved data acquisition and processing systems and methods, as such systems and methods may substantially reduce system dependence on imager orientation and may allow pupilometers to become more user friendly. Similarly, those skilled in the art will appreciate that a need exists for pupilometers that are capable of evaluating more than a mere pupilary response to light stimulus pulses. For example, it is believed that a substantial need exists for a pupilometer that is capable not only of measuring changes in pupilary diameter in response one or more light stimulus pulses, but also of evaluating pupil shape and/or segmental responses to a visual stimulus. Stated somewhat differently, it is believed that a substantial need exists for a pupilometer having a pupilary shape irregularity or non-uniformity detection capability. Finally, it is believed that a substantial need exists for pupilometer-based diagnostics systems, as such systems may provide medical practitioners with a cost effective, non-invasive means for gathering and assessing numerous physiologic parameters. SUMMARY OF THE INVENTION In one particularly innovative aspect, the present invention is directed toward a pupilometer having a pupil shape irregularity detection capability. For example, a pupilometer in accordance with the present invention may comprise an imaging sensor for generating signals representative of a pupil of an eye, a data processor coupled to the imaging sensor, and a program executable by the data processor for enabling the data processor to process signals received from the imaging sensor and to thereby identify one or more regions of non-uniformity or irregularity within an image of a perimeter of the imaged pupil. In one presently preferred embodiment, the one or more regions of pupilary non-uniformity or irregularity are identified by identifying a center point of a pupil and determining a plurality of radii representing distances from the center point to the perimeter of the pupil along a respective plurality of angles in a R,θ coordinate system. In another innovative aspect, the present invention is directed to a medical diagnostics system incorporating a pupilometer and medical database for correlating actual or derived pupilary image analysis data with stored medical data to formulate medical diagnoses, and to methods of implementing and utilizing such a diagnostics system. In still other innovative aspects, the present invention is directed to improved thresholding and image data processing algorithms for use within a pupilometer. For example, a pupilometer in accordance with the present invention may utilize a plurality of row and column histogram data sets in an iterative fashion to identify a preferred threshold value for locating the pupil of an eye within an image data frame. A pupilometer in accordance with the present invention also may process image frame data to determine a shape and/or diameter of the sclera/iris border of an eye and, thereafter, use the determined shape or diameter to evaluate an orientation of the eye of the patient and/or to correlate measured units with defined units of measurement. Finally, when provided with an additional armature supporting, for example, a visible light emitting diode (LED), a pupilometer in accordance with the present invention may be used to measure afferent or consensual pupilary responses to visual stimulus pulses. In such embodiments, a visual stimulus is applied to an eye under examination, and the response of the monitored pupil is recorded and evaluated. Then, as the monitored pupil is allowed to dilate, a stimulus pulse is applied to the other eye of the patient, to see whether or not the monitored pupil again constricts. Following the second stimulus pulse, the monitored pupil is allowed again to dilate, and a final visual stimulus is applied to the eye under examination. During the final stimulus pulse, the constrictive response of the monitored pupil (or lack thereof) is again measured. By measuring the response of the monitored pupil to each stimulus pulse, it is possible to detect retinal impairment in each eye of the patient. Other objects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a hand-held pupilometer in accordance with a preferred form of the present invention. FIG. 2 is an illustration of a liquid crystal display and keypad that may be provided on a hand-held pupilometer in accordance with the present invention. FIG. 3 is an enlarged cross-sectional view of an imaging section of a hand-held pupilometer in accordance with the present invention. FIG. 4 is a three-dimensional plan view showing a preferred arrangement of a plurality of IR, blue and yellow LEDs that may be used for ocular illumination and stimulation within a pupilometer in accordance with the present invention. FIG. 5 is a block diagram illustrating a group of programming objects that preferably comprise an operating program of a pupilometer in accordance with the present invention. FIG. 6 is a timing diagram illustrating a typical stimulus/illumination sequence for the IR, blue and yellow LEDs that may be used within a pupilometer in accordance with the present invention. FIGS. 7(a) and 7(b) are illustrations of histogram data sets that may be developed in accordance with a preferred thresholding algorithm utilized by a pupilometer in accordance with the present invention. FIG. 8 is a flow chart illustrating a basic operating protocol for a pupilometer in accordance with the present invention. FIG. 9 is an illustration of a pupilometer incorporating a consensual measurement attachment in accordance with the present invention. DESCRIPTION OF PREFERRED EMBODIMENTS A. Hardware Components of a Pupilometer in Accordance with the Present Invention Turning now to the drawings, FIG. 1 provides a cross-sectional view of a hand-held pupilometer 10 in accordance with the present invention. FIG. 2 provides an illustration of a liquid crystal display and key pad that may be provided on the hand-held pupilometer 10, and FIG. 3 is an enlarged cross-sectional view of an imaging section of the hand-held pupilometer 10. As shown in FIGS. 1-3, the pupilometer 10 preferably includes a housing 12 wherein an imaging sensor 14, an objective lens 16, first and second beam splitters 18 and 20, a shield 22, four infrared (IR) LEDs 24, two yellow LEDs 26, a blue LED 28 (shown in FIG. 4), a reticle 30, a battery 32, an image signal processing board 34 and a liquid crystal display 36 are mounted. Stated somewhat differently, the pupilometer may comprise a viewing port (reticle 30 and shield 22), an imaging system (objective lens 16, imaging sensor 14 and related image processing electronics), an illumination system (IR LEDs 24, blue LED 28 and related control circuitry) and a stimulus system (yellow LEDs 26 and related control circuitry). 1. The Viewing Port The viewing port (reticle 30 and shield 22) is provided to aid a user in properly positioning the pupilometer 10 for initial data acquisition. By looking through the reticle 30 and shield 22, the user of the pupilometer 10 is able to properly position the pupilometer 10 in front of an eye 38 of a patient, such that an image of the pupil of the patient's eye may be projected onto the imaging sensor 14. The reticle 30 preferably has circular targets (not shown) silk screened or etched on one surface. The targets are positioned along the user's line of sight so as to appear concentric with the iris and pupil of an eye 38 under observation. Those skilled in the art will appreciate that the reticle 30 and shield 22 also serve as environmental barriers and function to minimize exposure of the imaging system to caustic cleaning agents, biological material and airborne dust, all of which can have a negative impact upon the performance of the imaging system. 2. The Imaging System The imaging sensor 14 preferably comprises a N×M bit CMOS imaging sensor of a type that is commercially available. One such imaging sensor is the 384×288 bit, Model OV5017, CMOS imaging sensor manufactured and distributed by Omnivision Technologies, Inc. of Sunnyvale, Calif. The imaging sensor 14 is mounted to an imager board 31 of the pupilometer 10 and is coupled to a microprocessor (not shown) provided on a main processing or mother board 34 of the pupilometer 10. This allows for direct capture of digital images. Images in the form of 8 bit (or greater) gray scale bit maps are stored in system memory for image analysis and display on the liquid crystal display 36 (shown in FIG. 2). The microprocessor(not shown) preferably comprises an Elan SC 400 manufactured and distributed by Advanced Micro Devices, Inc., of Austin, Tex. The imaging system of the present invention is designed such that, when the hand-held pupilometer 10 is positioned in front of the eye 38 of a subject, a properly illuminated and in-focus image of the pupil 43 of the subject's eye 38 is obtained at the sensor plane 40 of the pupilometer 10. The objective lens 16 and a first beam splitter (i.e., wavelength selective filter) 18 preferably are used to focus an image of the pupil 43 of the subject's eye 38 on the sensor plane 40. In a preferred form, the objective lens 16 comprises a five element lens having a focal length of 7.0 mm. The first beam splitter 18 preferably comprises a glass substrate having a thickness of 1.6 mm that is coated with a multi-layer dielectric coating (not shown) to form a wavelength selective filter. The subject side 42 of the beam splitter 18 is coated to enhance reflection at the blue and infrared (IR) wavelength bands with a 45° angle of incidence. The user side 44 of the beam splitter 18 is AR coated to minimize effects resulting from multiple reflections in the image path. Thus, as shown in FIGS. 1 and 3, the beam splitter 18 functions to direct blue and/or IR light generated by the blue and IR LEDs 28 and 24, respectively, toward the eye 38 of a patient and to provide a return path to the imaging sensor 14 for blue and/or IR light that is reflected from the eye 38 ofthe patient. The microprocessor (not shown) provided on the main signal processing board 34 controls the operation and function of the various components comprising the imaging system as described more fully below. 3. The Illumination System The illumination system preferably comprises a blue light emitting diode (LED) 28 and four infrared (IR) LEDs 24. The IR LEDs 24 preferably are arranged symmetrically about the objective lens 16 of the imaging system. The IR LEDs 24 and blue LED 28 are coupled to a flex circuit 33 that is coupled to the main signal processing board 34. When activated by the microprocessor (not shown), the IR LED's 24 emit IR light preferably having a wavelength of substantially 850 nm. Thus, those skilled in the art will appreciate that the emission bandwidth of the IR LEDs 24 lies beyond the physiological response of the human eye but within the photoelectric response of the imaging sensor 14. Stated somewhat differently, while the human eye is unable to detect the IR light emitted by the IR LEDs 24, IR light generated by the IR LEDs 24 and reflected by the eye 38 of a subject may be detected by the imaging sensor 14. The four IR LEDs 24 preferably are arranged in diametrically opposed groups of two, as shown in FIG. 4. By arranging the IR LEDs 24 in the manner shown in FIG. 4, it is possible to more precisely control the IR illumination of a patient's eye 38 and, moreover, to achieve levels of 0, 50 and 100% illumination, if desired. The blue LED 28 is used for ocular illumination in situations where the sclera/iris border of a patient's eye 38 may be difficult to detect with IR illumination alone. As shown in FIG. 4, the blue LED 28 preferably is placed on the same radial arc that is defined by the IR LEDs 24, which surround the objective lens 16. The blue LED 28, when activated by the microprocessor (not shown), preferably emits light having a wavelength of substantially 470 nm. It has been discovered by the inventors hereof that light in the blue color band may be used to substantially improve sclera/iris border image contrast because the iris 37 and sclera 41 of a subject's eye 38 generally have substantially different light absorption and reflection characteristics in the blue color band. Thus, the use of a blue LED 28 for sclera/iris border imaging is believed to be a particularly innovative aspect of the present invention. Because the human eye is responsive to blue radiation, the blue LED 28 preferably is only activated for brief periods of time in relation to the temporal response of a subject's eye 38 or, alternatively, is used in conjunction with the stimulus LEDs 26 described below. Moreover, in a preferred form, IR and blue light illumination of the eye 38 of a subject may be performed in a multiplexed fashion, such that the eye of the subject is illuminated with IR light for a first period of time and, thereafter, illuminated with blue light for a second period of time. This is discussed more fully below with reference to FIG. 6. The microprocessor (not shown) provided on the main signal processing board 34 controls the operation and function of the various components comprising the illumination system as described more fully below. 4. The Stimulus System The stimulus system of the pupilometer 10 comprises two yellow LEDs 26 and a second beam splitter 20. The yellow LEDs 26 preferably are coupled to the flex circuit 33 and, when activated by the microprocessor (not shown), emit light having a wavelength of substantially 570 nm. Like the first beam splitter 18, the second beam splitter 20 preferably comprises a glass substrate having a thickness of 1.6 mm and is coated with a multi-layer dielectric coating (not shown) to form a wavelength selective filter. The subject side 50 of the beam splitter 20 is coated to enhance reflection at the yellow wavelength band with a 45° angle of incidence, and the user side 52 of the beam splitter 20 is AR coated to minimize effects resulting from multiple reflections in the user's observation path. The stimulus system of the pupilometer 10 preferably provides on-axis illumination of the pupil 43 of the eye 38 of a patient, as shown in FIG. 1. B. Software Components of a Pupilometer in Accordance with the Present Invention Turning now to FIGS. 5-7, a pupilometer 10 in accordance with the present invention is a microprocessor based system and, therefore, preferably includes several software components or modules for controlling its operation. As is well know in the art, an operating system provides fundamental machine level interfaces between the hardware elements comprising the pupilometer 10. More specifically, various device drivers are used to provide an interface between the microprocessor (not shown) and the imaging sensor 14, IR LEDs 24, yellow LEDs 26, blue LED 28, keypad 39 and liquid crystal display 36. The highest level of programming or code used within the pupilometer 10 is referred to herein as the P-Program, and the P-Program preferably is divided into five principal objects corresponding to different hardware and mathematical components. The five principal objects are illustrated in block diagram form in FIG. 5 and preferably include a graphic user interface (GUI) object 100, a stimulus/illumination object 102, a CMOS camera object 104, a feature extraction object 106 and an analysis object 108. All of the above-listed objects preferably are developed in Microsoft Visual C++ and Windows CE, and the graphic user interface (GUI) object 100 preferably is based on Win32 Api functions that are available in Windows CE. Visual C++ and Windows CE are software products distributed by Microsoft Corp. of Redmond, Wash. 1. Graphic User Interface (GUI) Object The graphic user interface object 100 allows for data/information exchange between a user and the pupilometer 10. Information relating to the current status of the pupilometer 10 including mode of operation (i.e., direct or consensual response, left or right eye measurement etc.) and the battery level is displayed via the graphic user interface object 100. All inputs and outputs of the pupilometer 10 preferably are coordinated via the graphic user interface object 100. Verification of subject ID numbers and/or patient identification data may be accomplished under control of the graphic user interface object 100. Measurement parameters are determined and set with the assistance of the graphic user interface object 100. Instructions during measurement sequences and images of the iris 37 of the eye 38 of a subject are provided on the liquid crystal display 36 under control of the graphic user interface object 100. Similarly, results of measurement sequences are displayed on the liquid crystal display 36 under control of the graphic user interface object 100, and the option to transfer measurement results to a printer or network computer (not shown) is available through the graphic user interface object 100. 2. Stimulus/Illumination Object The stimulus/illumination object 102 defines and controls the function of the yellow LEDs 26, IR LEDs 24 and blue LED 28 and, therefore, controls the stimulation and illumination of the eye 38 of a subject. The stimulus/illumination object 102 defines the various light profiles (i.e., yellow, IR and blue) as a function of time and controls activation of the yellow, IR and blue LEDs 26, 24 and 28, accordingly. In a typical stimulus/illumination sequence, the LEDs 26, 24 and 28 preferably are activated in the manner described below. However, those skilled in the art will appreciate that the stimulus/illumination sequence may be varied depending upon the circumstances of any given situation, and that variations in the stimulus/illumination sequence may be effected through the user interface object 100. During a typical stimulus/illumination sequence, the LEDs 24, 26 and 28 may be operated as shown in FIG. 6. For example, during a typical measurement sequence, the yellow LEDs 26 may be activated and deactivated for successive 1 second intervals (i.e., "on" for 1 second and "off" for 1 second) for a period of 10 seconds total. Simultaneously, the IR LEDs 24 may be activated for all periods when the yellow LEDs 26 are "off," and may be deactivated, activated and deactivated (i.e., turned "off," "on" and "off") for respective 0.04, 0.92 and 0.04 second intervals, while the yellow LEDs 26 are turned "on." Similarly, the blue LED 28 may be activated, deactivated and activated for respective 0.04, 0.92 and 0.04 second intervals, while the yellow LEDs 26 are turned "on," and may be deactivated during all periods when the yellow LEDs are turned "off." This allows for the operation of the IR LEDs 24 and blue LED 28 to be multiplexed. In such an embodiment, the image frame transfer rate preferably would be set, for example, to 50 frames per second. 3. The CMOS Camera Obiect The CMOS camera object 104 controls the transfer of image data frames between the CMOS imaging sensor 14 and memory associated with the microprocessor (not shown) provided on the main signal processing board 34 (i.e., between the imaging sensor 14 and the P-Program). Preferably, the rate of image frame transfer between the imaging sensor 14 and the memory associated with the microprocessor (not shown) may be programmably set within a range from 1 frame per second to 50 frames per second, depending upon the needs and/or desires of the user. However, those skilled in the art will appreciate that in some instances it may be desirable to provide for faster frame transfer rates, and that such rates might be as high or higher than 100 frames per second. The image frame acquisition or transfer rate is defined by the user under control of the graphic user interface object 100. 4. The Feature Extraction Object The feature extraction object 106 defines several image processing procedures that are used to isolate a pupil within an image and to extract several pupil features such as size, shape and position from each pupil image data frame. All processing procedures defined by the feature extraction object preferably are performed on each image data frame, with the exception of the automatic thresholding procedure described below. The automatic thresholding procedure is applied during an initial calibration phase and, therefore, does not need to be applied to each image data frame. Rather, the results of the automatic thresholding procedure are used during feature extraction processing for each image data frame. The results of the automatic thresholding procedure also may be used to set and/or adjust image exposure gain settings within the system. The feature extraction object 106 employs a flying spot processing algorithm to identify the center of the pupil, a fitted circumference and/or radius of the pupil and, preferably, 48 radii representing the distance between the center and perimeter of the pupil at 48 separate angles in an R,θ coordinate system, where θ defines an angular orientation about the center of the pupil, and R represents the radius of the pupil at that orientation. The fitted radius of the pupil is determined by selecting a circumference that best fits a contour of the pupil and by solving the equation 2πr to obtain the radius value (r). Those skilled in the art will appreciate that, by defining and evaluating 48 distinct radii about the center of the pupil, it is possible in accordance with the present invention to detect one or more non-uniformities or irregularities that may exist around the perimeter of the pupil. It also is possible to characterize the shape of the pupil as circular, elliptical etc. based upon the determined radii. It also is possible to evaluate selected sections of a pupil perimeter to determine whether or not those sections exhibit normal contour characteristics and/or normal responses to visual stimulus. It is believed that these capabilities represent significant improvements over conventional pupilometry systems, as these features allow not only for the performance of conventional pupil aperture and response evaluations, but also for the performance of pupil shape and sectional contour evaluations. Thus, where a particular affliction may produce a defined irregularity in pupil shape or defined sectional response to visual stimulus, the affliction may be identified through the use of a pupilometer in accordance with the present invention. The inputs to, and outputs obtained from, the flying spot algorithm may be defined as follows: Input Parameters: Frame=eye image frame generated by the CMOS imaging sensor 14 Threshold=gray level threshold value; any pixel having a gray scale value greater than the threshold value is considered to be part of the pupil. Output Parameters: Output=fitted radius and center of pupil, 48 radii. It is assumed herein that within the gray scale used by the pupilometer 10 the color black will be associated with a high gray scale value, such as 255, and the color white will be associated with a low gray scale value, such as 0. However, those skilled in the art will appreciate that the relative maximum and minimum values could be reversed. It is believed that the use of flying spot algorithms are well known in the art and, therefore, that the flying spot algorithm need not be described in detail herein. Nonetheless, the basic flying spot procedure may be described as follows. The flying spot procedure starts with a large circumference centered on the image of an eye and iteratively reduces the size of the circumference. In reducing the size of the circumference and adjusting the center location of the circumference, for each iteration the following momentums will be computed: ##EQU1## where N represents the number of pixels having coordinates x,y in the circumference contour; gray -- level -- sign(x,y) is +1, if the gray level value of the pixel (x,y) is greater than the threshold value; gray -- level -- sign(x,y) is -1, if the gray level value of the pixel (x,y) is less than the threshold value; and x0,y0 are the center coordinates of the circumference. The x and y coordinates of the circumference center and the radius are updated as follows: x0=x0+μx* Gain.sub.-- x y0=y0+μy* Gain.sub.-- y radius=radius+μr* Gain.sub.-- r. As indicated above, the updating procedure is applied iteratively, each time calculating the momentum and then changing the center and radius of the flying spot, such that the circumference finally converges to a circumference that best fits the contour of the pupil. Once the fitted radius and center of the pupil are determined, 48 radii representing the distance between the center and perimeter of the pupil at 48 separate angles in an R,θ coordinate system preferably are determined, where θ defines an angular orientation about the center of a pupil, and R represents the radius of the pupil at that orientation. By evaluating the 48 determined radii, it is possible to characterize the overall shape of the pupil and to determine whether or not any sectional non-uniformities or irregularities are present about the perimeter of the pupil. Such processing may be performed either by the feature extraction object 106 or the analysis object 108. Another principal function performed by the feature extraction object is thresholding. The thresholding function automatically identifies a gray level value that separates the pupil from the background in an image data frame. Moreover, when an appropriate threshold value is determined, all pixels having a gray level value greater than the threshold value are considered to comprise part of the image of the pupil, and all pixels having a gray level value less than the threshold are considered to correspond to background. Preferably, the defined threshold value represents the average of a maximum hypothetical threshold value and a minimum hypothetical threshold value. The maximum and minimum hypothetical threshold values are derived through respective histogram analysis routines. Moreover, as shown in FIGS. 7(a) and 7(b), for each hypothetical threshold value two histograms are evaluated, one for the rows of pixels within an image frame, and one for the columns of pixels within the image frame. The histogram value for a given row or column is determined by counting the pixel locations in that row or column that have a gray level value that exceeds the hypothetical threshold level. Thus, the number of values within a histogram preferably corresponds to the number of rows or columns in the image data frame, and each value represents the number of pixels in the specific row or column that have a gray level exceeding the hypothetical threshold value. Turning now in particular to FIGS. 7(a) and 7(b) the hypothetical maximum and hypothetical minimum threshold values are determined by iteratively altering a hypothetical threshold value until a prescribed histogram profile is achieved. An acceptable profile is illustrated in FIG. 7(a) and is one in which a null-high-null pattern is achieved for both a row histogram (y Hist) and column histogram (x Hist). More specifically, an acceptable profile preferably comprises a single "high" bordered by a pair of "nulls." Unacceptable profiles are illustrated, for example, in FIG. 7(b). The hypothetical maximum threshold value is determined by selecting an absolute maximum value and iteratively decreasing that value and deriving corresponding histogram data sets until acceptable row and column histogram profiles are achieved. Similarly, the hypothetical minimum threshold value is determined by selecting an absolute minimum value and iteratively increasing that value and deriving corresponding histogram data sets until acceptable row and column histogram profiles are achieved. Once the hypothetical maximum and minimum threshold values are determined, those values are averaged to determine the defined threshold value that will be used by the feature extraction object 106. Those skilled in the art will appreciate that the defined threshold value may correspond to the maximum hypothetical threshold value, the minimum hypothetical threshold value, or any value that is between those values. Thus, in alternative embodiments, the defined threshold value could be determined, for example, based on a weighted average of the maximum and minimum hypothetical threshold values. In such an embodiment, the defined threshold value may comprise a value corresponding to the sum of the minimum hypothetical threshold value and 2/3 of the difference between the maximum and minimum hypothetical threshold values. 5. The Analysis Object The analysis object 108 analyzes the configuration characteristics of a pupil as a function of time. Preferably, the analysis object 108 receives, as inputs, from the feature extraction object 106 a plurality of data sets for each captured image data frame. The data sets preferably include the time of image capture in msec, x and y coordinates of the pupil center, radius of the flying spot circumference, 48 radii representing the distance between the center and border of the pupil for 48 selected angles within an R,θ coordinate system, and an applied stimulus record for the relevant entry. Upon receiving the input data sets, the analysis object 108 preferably derives at least the following information from the data sets: minimum pupil aperture, maximum pupil aperture, difference between maximum and minimum pupil apertures, latency of pupil response to yellow light stimulus, pupil constriction velocity, first and second pupil dilation velocities and, if desired, pupil irregularity magnitude and location information. Where pupil irregularities are detected, the location of the irregularity preferably is identified by its θ coordinate. However, graphical indications also may be provided on the display 36 of the pupilometer 10. Further, in alternative embodiments, the analysis object 108 may include programming for effecting a multi-varied analysis wherein a plurality of selected variables including, for example, latency indicia, constriction velocity indicia, first and second dilation velocity indicia, segmental static and/or dynamic analysis indicia, constriction/dilation velocity ratio indicia, and maximum and minimum diameter indicia are evaluated for one or both eyes of a patient to arrive at one or more scalar values that are indicative of an overall physiologic or pathologic condition of the patient or, alternatively, to arrive at one or more scalar values that are indicative of an overall opto-neurologic condition of the patient. With regard to the information derived by the analysis object 108, the maximum pupil aperture, minimum pupil aperture and difference determinations require the identification of the maximum pupil aperture and minimum pupil aperture within a set of image data frames and, thereafter, computation of the difference between those values. The latency determination provides an indication in milliseconds of the time that it takes for a pupil to begin to respond to a visible (i.e., yellow) light stimulus pulse. Further, those skilled in the art will appreciate that, when a pupil is exposed to a visual light stimulus pulse, the pupil generally will, after some latency period, constrict and, once the stimulus is discontinued, dilate and return to its original size and configuration. Thus, the analysis object 108 evaluates the response of a pupil to a visual stimulus to determine a pupil constriction velocity and evaluates the response of the pupil to termination of the stimulus to determine first and second dilation velocities. First and second dilation velocities are evaluated because a pupil generally will dilate quickly for a first period of time and, thereafter, will dilate more slowly until its original size and configuration are achieved. Finally, as explained above, an analysis object 108 in accordance with the present invention also preferably identifies any irregularities in the shape of the pupil. Such irregularities may be either static or dynamic in nature. For example, a static irregularity may take the form of an irregular pupil shape in ambient light, whereas a dynamic irregularity may take the form of increased latency for a particular section of the pupil during a response to a the initiation or termination of a visual stimulus. With regard to static irregularities, such irregularities may be identified by identifying the angular orientations of radii that do not fall within prescribed limits, differ from other calculated radii by a predetermined deviation or differ from the fitted radius by a predetermined amount, deviation or percentage. Finally, an analysis object 108 in accordance with the present invention preferably includes programming for identifying statistical anomalies within derived results. This allows an analysis object 108 in accordance with the present invention to discard either actual pupilary response data sets (i.e., fitted radius, center and radii calculations) or derived data sets (i.e., max aperture, min aperture, latency, constriction rate or dilation rates) when a selected value differs from other values by a statistically significant degree. When such anomalies are identified, the relevant data sets are not included in averaging functions, and where many anomalies are identified, an imaging sequence will be invalidated and must be repeated. C. Operation of a Pupilometer in Accordance with the Present Invention Turning now to FIG. 8, operation of a pupilometer 10 in accordance with the present invention proceeds as follows. Generally the pupilometer 10 will be configured according to a default mode of operation. The default mode defines a set of values for basic operation of the device. The defined values may include, for example, values for scan duration, illumination duration and/or profile, stimulus duration and/or profile and stimulus intensity level. However, it will be appreciated that all of the above-listed values may be programmably set under control of the graphic user interface object 100. Thus, it will be appreciated that default programming values generally will be utilized by the pupilometer 10 absent entry of an override by the user in a scan sequence program mode. A typical image acquisition and analysis procedure may proceed as follows. If the pupilometer 10 has been idle for a predetermined period of time (e.g., 120 seconds), the pupilometer 10 is automatically placed in a battery-conserving sleep mode (step 202). By depressing the "scan" button 45 (shown in FIG. 2), the user causes the pupilometer 10 to enter a "ready" mode (step 200). At this time, the user is prompted to enter an alphanumeric subject or patient identification number via the keypad 39 or to download any necessary patient information from a network computer via an infrared data interface, such as an IrDA interface that is provided on numerous conventional personal computer products (step 204). Once any requisite patient identification data has been entered into the system, the user is prompted via the liquid crystal display 36 or an audio prompt to hold down the "scan" button 45 and to position the pupilometer 10 in front of the eye 38 of a subject (step 210). When the user depresses the "scan" button 45, the microprocessor (not shown) initiates an imaging test sequence. The yellow LEDs 26 preferably are not activated during the test sequence. During the test sequence the images that are acquired by the imaging sensor 14 may be displayed on the liquid crystal display (LCD) 36. Preferably, the P-program analyzes the image data frames that are acquired during the test sequence, determines whether or not the pupilometer 10 is properly positioned for obtaining measurements, and determines if all necessary parameters are met to ensure high-quality data recovery. If the test criteria are not met, the user is prompted to reposition the pupilometer 10. After any requisite test criteria are met, the P-program will continue to run the test sequence until the "scan" button 45 is released. Once the scan button 45 is released, the P-program preferably will initiate a prescribed measurement sequence and will activate the illumination system of the pupilometer 10 as needed during the measurement sequence. Upon completion of the measurement sequence, the user is informed via the LCD 36 or an audio prompt that the measurement sequence has been completed (steps 226-228). Following completion of the measurement sequence, the P-program preferably will analyze the image data frames that have been obtained and will display the results of the analysis on the LCD 36. If the results are satisfactory (i.e., are statistically sound), the user may then be prompted to download the results to a printer or related network via the IrDA interface (not shown) (step 246). If the results are not satisfactory, the user is prompted to repeat the measurement sequence (step 222). Finally, after an initial set of measurement are obtained, the user may be prompted for a decision to measure the pupilary characteristics of the other eye of the subject/patient, or the user may be prompted for a decision to make a consensual response measurement (steps 238, 242). The consensual response measurement may take the form of a "swinging flashlight" measurement discussed more fully below. If a consensual measurement is to be performed, the user may be prompted to couple a consensual measurement attachment (shown in FIG. 9) to the pupilometer and to position a yellow LED 52 mounted on the attachment in front of the appropriate eye of the subject/patient. If the consensual measurement attachment is permanently affixed to the pupilometer 10, the user may only need to deploy and/or properly position the attachment. D. Incorporation of Consensual Measurement Apparatus in a Pupilometer in Accordance with the Present Invention Turning now to FIG. 9, a pupilometer 10 in accordance with the present invention may incorporate a consensual measurement apparatus or armature 50 to enable consensual pupilary responses to be analyzed. In a preferred embodiment, the armature 50 may detachably engage a main body 11 of the pupilometer 10. However, as explained above, the armature 50 also may be permanently affixed to the main body 11 of the pupilometer 10. One test for analyzing consensual pupilary responses is commonly referred to within the medical community as a "swinging flashlight test." During a typical swinging flashlight test one eye of a subject is monitored, and a visible light stimulus is applied first to the eye of the patient that is being monitored, then to the eye of the patient that is not monitored and, finally, again to the eye that is monitored. If the eyes of the patient are normal, the pupil of the monitored eye should constrict in response to all of the light stimulus pulses (regardless of which eye the stimulus pulse is applied to). Following application of the first light stimulus, the pupil of the monitored eye should begin to dilate, and upon application of the second light stimulus (i.e., upon application of stimulus to the non-monitored eye), the pupil of the monitored eye should again constrict. If the monitored pupil does not respond adequately to the second stimulus pulse, it may be inferred that the retina of the non-monitored eye somehow may be impaired. If the monitored pupil does not respond adequately to the third stimulus pulse, it may be inferred that the retina of the monitored eye somehow may be impaired. By using a consensual measurement attachment 50 in accordance with the present invention, it is possible to perform a "swinging flashlight" test using the pupilometer 10. For example, the when performing a "swinging flashlight" test, the P-program may first cause the yellow LEDs 26 within the pupilometer 10 to be activated for a period of, for example, 1 second. The P-program then may deactivate the yellow LEDs 26, and 0.5 second following deactivation of the yellow LEDs 26 may activate for 0.5 second the yellow LED 52 located at the distal end 54 of the consensual attachment. Finally, after deactivating the yellow LED 52 and waiting for a period of, for example, 0.5 second, the P-program may again activate the yellow LEDs 26 for a period of 1 second. Image frames may be obtained by the imaging sensor 14 at a rate of, for example, 10 frames per second and for a total period of 5.0 or more seconds to evaluate the consensual response of the imaged eye. If desired, the process may be repeated a predetermined number of times. E. Miscellaneous System Calibration and Pupil Identification Processing Techniques In alternative embodiments, the P-program of a pupilometer 10 in accordance with the present invention may incorporate a calibration algorithm that uses acquired data descriptive of the perimeter of the iris 37 of the eye 38 of a patient to define a relationship between pixel spacing data and real world measurement parameters and/or to evaluate an orientation of a patient's eye 38 in relation to the pupilometer 10. For example, in one innovative aspect, the P-program of a pupilometer 10 may cause the iris of the eye of a patient to be illuminated by blue light (i.e., may activate the blue LED 28) and, while the patient's eye is so illuminated, may obtain an image of the sclera/iris border of the patient's eye. A flying spot or similar processing algorithm may then be used to identify a best fitting elliptical circumference for the sclera/iris border of the patient's eye, and the radii or horizontal and vertical diameters of the circumference may be compared to or correlated with assumed sclera/iris border radii or diameters to provide a correlation between a pixel count and a real world measurement. For example, if the horizontal diameter of a sclera/iris border is assumed to be 11.7 mm, and the sclera/iris border measures 117 pixels in diameter, the P-program of the pupilometer 10 may derive a pixel measurement to real world correlation factor of 10 pixels/mm, and that correlation factor may be used to provide the user with pupil measurement information. In accordance with one preferred form of the present invention, the horizontal diameter of the sclera/iris border is assumed to be 11.75 mm for in all subjects. However, those skilled in the art will appreciate that a different diameter, such as 11.0 mm or 12.0 mm, may also be assumed. Similarly, by evaluating the shape of the sclera/iris border of an eye it is possible to estimate the angular orientation of the eye with respect to the pupilometer 10 and, moreover, to evaluate the orientation of an eye with relation to a vertical axis of the eye. Preferably, this may be done by evaluating a degree of ellipticity of the imaged sclera/iris border and assuming that the shape of the sclera/iris border has a predetermined elliptical shape. Such, measurements may be further refined by comparing the shape of a pupil to the shape of a surrounding sclera/iris border to determine whether variations in the shape of a pupil arise from angular orientation of the eye in relation to the pupilometer 10, or from non-uniformities or irregularities in the perimeter of the pupil. In another innovative aspect, a pupilometer 10 in accordance with the present invention may include software for utilizing physical landmarks to assist in locating a pupil within an image data frame. In such an embodiment, the feature extraction object 106 of the P-program executed by the microprocessor (not shown) may include code for identifying characteristic structures of ocular tissue such as eyelids and/or eyelashes within an image data frame, and for using the location of those structures to predict the location of a pupil within the image data frame. Additional landmarks that may be located in accordance with the present invention include the lachrymal punctum, lachrymal caruncula, and lateral and medial papebral commisures of a patient's eye. These landmarks also may be used to identify which eye of a patient is being monitored. F. Diagnostics Systems and Methods in Accordance with the Present Invention In still another innovative aspect, the present invention is directed to improved diagnostics systems and methods incorporating a pupilometer 10 and medical database (not shown). For example, it is contemplated in accordance with the present invention that data representative of a plurality of pupilary response or configuration characteristics associated with one or more physical or pathological conditions may be stored within a medical diagnostics data base, that a pupilometer 10 may be used to obtain data descriptive of one or more pupilary response or configuration characteristics from a patient, and that the obtained data may be compared to the stored data within a data analysis system to identify one or more physiologic or pathologic characteristics or conditions of the patient. Further, in a preferred form, the obtained and/or stored pupil configuration data may be descriptive of one or more static or dynamic regional non-uniformities that may exist within the perimeter of a patient's pupil. While the invention is susceptible to various modifications and alternative forms, specific examples thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims.

A pupilometer having a pupil irregularity or non-uniformity detection capability. The pupilometer may comprise an imaging sensor for generating signals representative of a pupil of an eye, a data processor; and a program executable by the data processor for enabling the data processor to process signals received from the imaging sensor and to thereby identify one or more regions of non-uniformity within an image of a perimeter of the pupil. The pupilometer may incorporate several innovative calibration and thresholding routines and may provide the basis for an innovative medical diagnostics system, when coupled to a network containing a suitable medical database and data processing hardware.

BACKGROUND OF THE INVENTION The present invention relates to a recording/playback apparatus with telephone and its control method, a video camera with telephone and its control method, an image communication apparatus, and a storage medium. Since a conventional video camera and telephone are used for different purposes, they have independent product forms. In recent years, upon development of semiconductors, communication techniques, and the like, proliferation of the information industries represented by the Internet, broadening of the range of consumers' needs, and so on, various product forms have emerged. Even in a video camera, there are needs to not only for a photographer or a person whose image is sensed personally observe the image, but also to quickly transmit video data as a kind of information to a broad range of recipients via a public line. However, since information sensed by a video camera is temporarily saved in a recording medium, and is then transmitted via the public line, troublesome operation for the operator for connecting a device such as a telephone or the like and the video camera via an interface device, and transmitting information, and a special device therefor are required. Also, on the receiving side of that information, some device for receiving the information, cumbersome operation for waiting for the information after preparation for receiving the information, and a special device therefor are required. As a method of solving this problem, a device that integrates a camera and telephone, which is called a videophone, has been developed. FIG. 1 shows the arrangement of a conventional videophone. Referring to FIG. 1, reference numeral 1 denotes a lens; 2 , a stop of the lens; 3 , a motor for driving a zoom lens; 4 , a driving means for driving the zoom lens; 5 , a motor for driving the stop; 6 , a driving means for driving a stop mechanism; 7 , a motor for driving a focus lens; and 8 , a driving means for driving the focus lens. Reference numeral 9 denotes an image sensing element (CCD); 10 , a CDS/AGC circuit for sampling & holding a video signal output from the image sensing element, and performing AGC (auto gain control) of the video signal; 11 , an A/D converter for converting an analog signal into a digital signal; 12 , a camera signal processing circuit for processing luminance and color signals to obtain an appropriate video signal; and 13 , an image compression/expansion circuit for compressing/expanding an image. The image compression/expansion circuit 13 uses, for example, JPEG, H263, a DV format, or the like. Reference numeral 14 denotes a memory; 15 , a communication protocol circuit; 16 , a PHS transmitter/receiver;. 17 , a microcomputer; 18 , a D/A converter for converting a digital signal into an analog signal; 19 , an antenna; 20 , a monitor (or a liquid crystal display device); 21 , a key discrimination circuit; and 22 , a ten-key pad for inputting a telephone number. Reference numeral 23 denotes a microphone; 24 , an audio signal processing circuit for processing an audio signal input from the microphone to obtain an appropriate signal; and 25 , an A/D converter for converting an analog audio signal into a digital signal. The operation of the above arrangement will be explained below. Incoming light from an object via the lens 1 is photoelectrically converted into an electrical signal by the image sensing element 9 . The electrical signal is processed by the camera signal processing circuit 12 to obtain a video signal. Furthermore, the video data is compressed by the image compression/expansion circuit 13 , and the compressed data is stored in the memory 14 . The data compressed by the image compression/expansion circuit 13 is processed by the communication protocol circuit 15 to obtain data according to a prescribed communication protocol, and the processed data is transmitted from the antenna 19 via the PHS transmitter/receiver 16 . The data output from the camera signal processing circuit 12 is converted into an analog signal by the D/A converter 18 , and the analog signal is processed to be displayed on the monitor. After that, an image is output to the monitor. Moreover, image and audio radio signals transmitted from an external device are received by the PHS transmitter/receiver 16 via the antenna 19 , and image and audio data are obtained via the communication protocol circuit 15 . The image data is then expanded by the image compression/expansion circuit 13 , and is output to the monitor via the D/A converter 18 . The microcomputer 17 controls the system of this apparatus, and performs various kinds of lens control (control of the focus lens, zoom lens, and stop), camera signal processing control, communication control, key control, and the like. The ten-key pad 22 is used for inputting a telephone number of the called party upon placing a call, and the discrimination circuit 21 discriminates the input key. The output from the discrimination circuit 21 is input to the microcomputer 17 , which executes a series of control processes for placing a call. The same applies to an audio signal. That is, after a voice is input from the microphone 23 , the audio signal is processed by the audio signal processing circuit 24 , and is input to the communication protocol circuit 15 via the audio A/D converter 25 . After that, the audio signal is transmitted as a radio signal from the antenna 19 via the PHS transmitter/receiver as in the video signal. However, the conventional videophone has no special function, e.g., a function of automatically adjusting the focus on a person designated on a screen, or a function of optimizing exposure of a person designated on the screen, upon sensing an image by the camera. Even if such functions are available, they are not suitable for a product like a videophone for which a compact structure is of prime importance, since operation keys therefore must be added. Also, in the conventional videophone, since the function of placing a call and a function of sensing an image by the camera are simultaneously executed, the battery is used up soon. In addition, an operation means for placing a call, and an operation means for sensing a camera image are separately present, and such means are not suitable for a product like a videophone for which a compact structure is of prime importance, since operation keys therefore must be further added. SUMMARY OF THE INVENTION The present invention has been made in consideration of the conventional problems, and has as its object to improve the operability of both a recording/playback apparatus or video camera with a telephone function, and the telephone function. It is another object of the present invention to provide an image communication apparatus which can automatically adjust the focus on a designated object. It is still another object of the present invention to provide an image communication apparatus which can optimize the exposure value of a designated object. It is still another object of the present invention to provide an image communication apparatus which can enlarge or reduce the image of a designated object. It is still another object of the present invention to provide an image communication apparatus which can easily select a menu displayed on a monitor. It is still another object of the present invention to provide an image communication apparatus which can be rendered compact by reducing the number of operation keys. In order to solve the aforementioned problems and to achieve the above objects, a recording/playback apparatus with telephone according to the present invention is characterized by the following arrangement. That is, a recording/playback apparatus with telephone, which has a telephone and recorder/player in a single housing, comprises means for muting a ringing tone upon reception of a call during recording by the recorder/player. A video camera with telephone according to the present invention is characterized by the following arrangement according to its first aspect. That is, a video camera with telephone, which has a telephone and video camera in a single housing, comprises means for muting a ringing tone upon reception of a call during image sensing by the video camera. A video camera with telephone according to the present invention is characterized by the following arrangement according to its second aspect. That is, a video camera with telephone, which has a telephone and video camera in a single housing, comprises means for pausing image sensing of the video camera upon reception of a call during image sensing by the video camera. A video camera with telephone according to the present invention is characterized by the following arrangement according to its third aspect. That is, a video camera with telephone, which has a telephone and video camera in a single housing, comprises means for stopping various call reception informing functions that disturb image sensing, and displaying a call reception message on a display, upon reception of a call during image sensing by the video camera. A video camera with telephone according to the present invention is characterized by the following arrangement according to its fourth aspect. That is, a video camera with telephone, which has a telephone and video camera in a single housing, comprises selection means for selecting a function of stopping various call reception informing functions that disturb image sensing, and displaying a call reception message on a display, upon reception of a call during image sensing by the video camera. A method of controlling a recording/playback apparatus with telephone according to the present invention is characterized by the following arrangement. That is, a method of controlling a recording/playback apparatus with telephone, comprises the step of muting a ringing tone upon reception of a call during recording by the recording/playback apparatus. A method of controlling a video camera with telephone according to the present invention is characterized by the following arrangement according to its first aspect. That is, a method of controlling a video camera with telephone, comprises the step of muting a ringing tone upon reception of a call during image sensing by the video camera. A method of controlling a video camera with telephone according to the present invention is characterized by the following arrangement according to its second aspect. That is, a method of controlling a video camera with telephone, comprises the step of pausing image sensing of the video camera upon reception of a call during image sensing by the video camera. A method of controlling a video camera with telephone according to the present invention is characterized by the following arrangement according to its third aspect. That is, a method of controlling a video camera with telephone, comprises the step of stopping various call reception informing functions that disturb image sensing, and displaying a call reception message on a display, upon reception of a call during image sensing by the video camera. A method of controlling a video camera with telephone according to the present invention is characterized by the following arrangement according to its fourth aspect. That is, a method of controlling a video camera with telephone, comprises the step of selecting a function of stopping various call reception informing functions that disturb image sensing, and displaying a call reception message on a display, upon reception of a call during image sensing by the video camera. A storage medium according to the present invention is characterized by the following arrangement according to its first aspect. That is, a storage medium stores a program for implementing a method of controlling a recording/playback apparatus with telephone of a method of controlling a recording/playback apparatus with telephone, comprising the step of muting a ringing tone upon reception of a call during recording by the recording/playback apparatus. A storage medium according to the present invention is characterized by the following arrangement according to its second aspect. That is, a storage medium stores a program for implementing a method of controlling a video camera with telephone of a method of controlling a video camera with telephone, comprising the step of muting a ringing tone upon reception of a call during image sensing by the video camera. A storage medium according to the present invention is characterized by the following arrangement according to its third aspect. That is, a storage medium stores a program for implementing a method of controlling a video camera with telephone of a method of controlling a video camera with telephone, comprising the step of pausing image sensing of the video camera upon reception of a call during image sensing by the video camera. A storage medium according to the present invention is characterized by the following arrangement according to its fourth aspect. That is, a storage medium stores a program for implementing a method of controlling a video camera with telephone of a method of controlling a video camera with telephone, comprising the step of stopping various call reception informing functions that disturb image sensing, and displaying a call reception message on a display, upon reception of a call during image sensing by the video camera. A storage medium according to the present invention is characterized by the following arrangement according to its fifth aspect. That is, a storage medium stores a program for implementing a method of controlling a video camera with telephone of a method of controlling a video camera with telephone, comprising the step of selecting a function of stopping various call reception informing functions that disturb image sensing, and displaying a call reception message on a display, upon reception of a call during image sensing by the video camera. An image communication apparatus according to the present invention is characterized by the following arrangement according to its first aspect. That is, an image communication apparatus comprises an image sensing element for photoelectrically converting light coming from an object, and outputting an image signal, focusing means for focusing the light coming from the object on the image sensing element, focus adjustment means for adjusting a focus position of the focusing means, display means for displaying at least an image sensed by the image sensing element, area setting means for setting an area including an object image to be focused on the image sensing element on a screen of the display means, driving means for driving the focus adjustment means to focus the object image in the area set by the area setting means on the image sensing means, transmission means for transmitting data including an image signal sensed by the image sensing element by radio, and reception means for receiving data from another apparatus by radio. An image communication apparatus according to the present invention is characterized by the following arrangement according to its second aspect. That is, an image communication apparatus comprises an image sensing element for photoelectrically converting light coming from an object, and outputting an image signal, focusing means for focusing the light coming from the object on the image sensing element, stop adjustment means for adjusting a stop of the focusing means, display means for displaying at least an image sensed by the image sensing element, area setting means for setting an area including an object image, which is to have an appropriate exposure value on the image sensing element, on a screen of the display means, driving means for driving the stop adjustment means to obtain an appropriate exposure value of the object image in the area set by the area setting means on the image sensing means, transmission means for transmitting data including an image signal sensed by the image sensing element by radio, and reception means for receiving data from another apparatus by radio. An image communication apparatus according to the present invention is characterized by the following arrangement according to its third aspect. That is, an image communication apparatus comprises an image sensing element for photoelectrically converting light coming from an object, and outputting an image signal, display means for displaying at least an image sensed by the image sensing element, image enlargement/reduction means for enlarging or reducing an image on the display means, area setting means for setting an area including an object image to be enlarged to reduced on a screen of the display means, control means for controlling the image enlargement/reduction means to enlarge or reduce the object image in the area set by the area setting means, transmission means for transmitting data including an image signal sensed by the image sensing element by radio, and reception means for receiving data from another apparatus by radio. An image communication apparatus according to the present invention is characterized by the following arrangement according to its fourth aspect. That is, an image communication apparatus comprises an image sensing element for photoelectrically converting light coming from an object, and outputting an image signal, display means for displaying at least an image sensed by the image sensing element and/or a character, selection means for displaying a menu used for selecting or executing one of a plurality of functions on the display means, and selecting a predetermined function from the displayed menu, transmission means for transmitting data including an image signal sensed by the image sensing element by radio, and reception means for receiving data from another apparatus by radio. In the image communication apparatus according to the present invention, the display means further displays an image signal in the data received from the other apparatus. An image communication apparatus according to the present invention is characterized by the following arrangement according to its fifth aspect. That is, an image communication apparatus comprises image sensing means for sensing an object image, transmission/reception means for transmitting/receiving data by radio, operation means for operating the image sensing means and the transmission/reception means, and switching means for switching the operation means between a state for operating the image sensing means, and a state for operating the transmission/reception means. Other objects and advantages besides those discussed above shall be apparent to those skilled in the art from the description of a preferred embodiment of the invention which follows. In the description, reference is made to accompanying drawings, which form a part hereof, and which illustrate an example of the invention. Such example, however, is not exhaustive of the various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a prior art; FIG. 2 is a front perspective view of the first embodiment of the present invention; FIG. 3 is a rear perspective view of the first embodiment; FIG. 4 is a block diagram of the first embodiment; FIG. 5 is a block diagram of a CPU shown in FIG. 4; FIG. 6 is a flow chart showing the operation of the first embodiment; FIG. 7 is a sequence chart of the first embodiment; FIG. 8 is a front view showing a display example on a display in the first embodiment; FIG. 9 is a block diagram of an image communication apparatus according to the second embodiment of the present invention; FIG. 10 shows the layout of operation switches; FIG. 11 is a block diagram of an image communication apparatus according to the third embodiment of the present invention; FIG. 12 is a block diagram of an image communication apparatus according to the fourth embodiment of the present invention; FIG. 13 is a block diagram of an image communication apparatus according to the fifth embodiment of the present invention; FIG. 14 shows the layout of operation keys in the fifth embodiment; FIG. 15 is a block diagram of an image communication apparatus according to the sixth embodiment of the present invention; FIG. 16 shows the layout of operation switches; FIG. 17 is a flow chart showing the operation of the image communication apparatus of the sixth embodiment; FIG. 18 shows another example of the switch layout; and FIG. 19 is a block diagram of an image communication apparatus according to the seventh embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described in detail hereinafter with reference to the accompanying drawings. (First Embodiment) FIG. 2 is a front perspective view of a video camera with telephone according to the first embodiment of the present invention. Referring to FIG. 2, reference numeral 300 denotes a video camera main body with telephone; 301 , an antenna; 302 , an external input/output terminal; 303 , a camera; 304 , a loudspeaker for outputting a received voice; 305 , a display for outputting a received image or an image sensed by the video camera main body; 306 , operation keys; 307 , a microphone; and 310 , a trigger switch. FIG. 3 is a rear perspective view of the video camera with telephone shown in FIG. 2 . Referring to FIG. 3, reference numeral 308 denotes an insertion panel of a recording medium; and 309 , an external power supply for the video camera main body with telephone. In the video camera with telephone having the above arrangement, the operator inserts a recording medium into the recording medium insertion panel 308 upon sensing an image by the video camera, and records an image sensed by the camera 303 , a voice picked up by the microphone 307 , and various kinds of information such as image sensing information and the like on the recording medium. To access a radio public telephone network or a partner station, the operator operates the operation keys 306 to connect to a radio transmission path via the antenna 301 so as to establish connection with the partner station. Upon establishing connection, video data sensed by the camera 303 , audio data input by the microphone 307 , and various kinds of information for control are transmitted as transmission information. Of received information, video information is displayed on the display 305 , and audio information is output to the loudspeaker 304 . Also, such received information can be recorded on the recording medium. The video camera with telephone may be remote-controlled by received control information. Upon receiving a call by access from the radio public network or the partner station during image sensing by the operator, the video camera with telephone operates in accordance with a call reception mode and a video camera operation mode of the video camera main body 300 with telephone, which are set by the operator. The video camera operation mode is selected from a-1: no mode change, and a-2: pause image recording. If a-1 is selected, no mode change is made; if a-2 is selected, the control enters an image recording pause mode. The call reception mode is selected from b-1: normal call reception, and b-2: image recording call reception. If b-1 is selected, normal call reception proceeds, i.e., an alerting bell, vibrator, LED, or the like functions; if b-2 is selected, image recording call reception proceeds, and the call reception function is stopped if it may disturb normal image recording. The call reception function that may disturb normal image recording includes sound produced by the alerting bell, vibration generated by the alerting vibrator, and a light source such as the call reception LED. In case of image recording call reception, a call reception message is displayed on the display 305 . At this time, the telephone number of the calling party, video information, importance level of the access purpose, subject matter, and the like are additionally displayed. Furthermore, as the video camera operation mode, other operation modes such as a stop mode, and the like, a mode of turning off the video camera unit, and the like may be added. Also, as the call reception mode, a call reception deny mode, transfer mode, automatic answering mode, and the like may be added. The display 305 can display an image sensed by the camera 303 , and received information. Various kinds of information obtained can be input/output via the external input/output terminal 302 . The video camera with telephone operates on the battery 309 . The call reception mode and video camera operation mode are set using the operation keys 306 . The recording medium is not particularly limited. For example, a magnetic tape, solid-state memory, and the like may be used. FIG. 4 is a block diagram of the video camera with telephone in the first embodiment. Referring to FIG. 4, reference numeral 200 denotes the overall block of the video camera with telephone; 201 , a lens for receiving an image; 202 , a solid-state sensor for converting an image into an electrical signal; 203 , an A/D converter for converting an analog signal into digital data; 204 , a motor for driving the lens 201 ; 205 , an alerting vibrator for informing the operator of reception of an incoming call; 209 , a microphone for picking up a voice; 210 , a microphone amplifier for amplifying an audio signal; 211 , an A/D converter for converting an audio signal into digital data; 212 , operation keys used for operating the video camera 200 with telephone; 213 , a display driver for converting an image into a display format; 214 , a display for displaying an image; 215 , a loudspeaker driver for outputting an audio signal; 216 , a loudspeaker; 217 , an external input/output terminal for inputting/outputting various kinds of information; 218 , a PHS interface for performing line control of, e.g., a PHS or the like; 219 , an RF circuit for converting transmission data into radio data; 220 , an antenna; 221 , a power supply; 222 , an external memory; 223 , a recorder/player; and 230 , a CPU for controlling the video camera system with telephone. FIG. 5 is a block diagram showing the CPU 230 in FIG. 4 in detail. Referring to FIG. 5, reference numeral 251 denotes a clock circuit for operating the CPU; 252 , a CPU core; 253 , a ROM for storing a program; 254 , a RAM for storing data; 255 , a memory controller for controlling an external memory and the like; 256 , a bus controller for controlling a bus; 257 , an I/O controller for interfacing external input/output; 258 , a programmable pulse generator (PPG) for generating pulse data; 259 , a serial communication interface (SCI) for controlling communications with an external device; 260 , an extra bus controller for controlling communications with an external bus; 261 , a D/A converter for converting digital data into analog data; 262 , a display controller for controlling the display; and 263 , a DMA for data transfer. The individual blocks are connected to each other via a data bus, address bus, and control bus. In the block diagram shown in FIG. 4, incoming light from an object via the lens 201 is converted into an electrical signal by the solid-state sensor 202 . The electrical signal is sampled by the A/D converter 203 to be converted into digital signal, and is input to the CPU 230 as a digital video signal. The lens 201 is driven by the motor 204 in accordance with a control command from the CPU : 230 to attain an auto-focus function and zoom function. A timing signal for reading data from the solid-state sensor 202 is generated by the CPU 230 . An audio signal picked up by the microphone 209 is amplified by the microphone amplifier 210 , and is sampled by the A/D converter 211 to be converted into digital data. The digital audio data is input to the CPU 230 . The digital video data undergoes basic processes such as color separation, white balance, gamma correction, aperture correction, and the like, and additional processes such as image size/image quality adjustment, position adjustment, and the like set using the operation keys 212 of the video camera 200 with telephone. Furthermore, the digital video data is compressed by a pre-set compression method and compression parameters to obtain compressed image data. The audio data undergoes additional processes such as audio adjustment set using the operation keys 212 of the video camera 200 with telephone, and is compressed by the pre-set compression method and compression parameters to obtain compressed audio data. The compressed image and audio data are re-formatted as radio transmission data, and are sent to the PHS interface 218 as transmission data together with control data. Also, the compressed image and audio data are sent to the recorder/player 223 , and are recorded in an image recording mode. Furthermore, the compressed image and audio data are sent to the external input/output terminals 217 as needed. Moreover, the compressed image data is expanded as needed (in response to an operation of a corresponding one of the operation keys 212 ), and is displayed on the 214 via the display driver 213 as an image used for confirming transmission video data. Data converted according to the radio protocol by the PHS interface 218 is modulated by the RF circuit 219 , and the modulated data is transmitted from the antenna 220 . On the other hand, radio data received at the antenna 220 is demodulated by the RF circuit 219 , and is converted according to the radio protocol by the PHS interface 218 to obtain received data. The received data is sent to the CPU 230 . The received data is separated into received control data, received compressed audio data, and received compressed audio data, and the video camera 200 with telephone is controlled according to the received control data. The received compressed audio data is expanded and output to the loudspeaker 216 via the loudspeaker driver 215 . The received compressed image data is expanded and output to the display 214 via the display driver 213 . The external memory 222 such as a DRAM, SRAM, or the like is used for the data process of the CPU 230 . The external memory 222 can save a sensed image, received image, recorded voice, received voice, and the like. The power of the video camera 200 with telephone is supplied from the power supply 221 . The alerting vibrator 205 vibrates to inform the user of reception of an incoming call upon receiving a call in the normal call reception mode. The operation of the CPU 230 shown in the block diagram in FIG. 5 will be explained below. The clock circuit 251 generates CPU driving clocks, and supplies them to peripheral circuits. In this embodiment, fundamental clocks of 27 MHz are multiplied 10-fold by a PLL to obtain driving clocks of 270 MHz for the CPU 230 . The ROM 253 is a memory that stores program codes, and a program is executed by those codes. This memory may be replaced by a flash memory, EEPROM, or the like. The RAM 254 serves as a data memory for temporarily saving data. The memory controller 255 is a circuit block for interfacing with an external memory, which is used for temporarily saving large-size data such as image data, audio data, and the like. The display controller 262 is a circuit block for converting digital image data into output data to be sent to the display 214 . The D/A converter 261 is used for, e.g., converting digital audio data into analog data. The serial communication interface 259 makes serial data communications with external peripheral circuits, the PHS interface 218 , and the like. The programmable pulse generator 258 generates driving pulses for the alerting vibrator, solid-state sensor, and motor. At this time, by arbitrarily setting the driving pulses for the solid-state sensor, various input conditions such as the size, the number of pixels, and the like of an input image can be arbitrarily set. The I/O controller 257 serves as a data I/O interface, which inputs/outputs digital image data, digital audio data, operation key inputs, and other control signals. These blocks are connected via the bus, which is controlled by the bus controller 256 , and transfers data under the control of the DMA 263 . Also, the bus can be connected to an external bus via the extra bus controller 260 . Using these peripheral circuits, the CPU core 252 executes data processes. In this embodiment, the PHS is used for radio transmission. However, communication bands, methods, and the like are not particularly limited. For example, an analog radio telephone, W-CDMA, and the like may be used. FIG. 6 shows some steps of the flow chart of the CPU 230 . The flow starts in step S 100 , and it is checked in step S 101 if an incoming call is detected. If NO in step S 101 , the flow jumps to step S 110 ; otherwise, it is checked in step S 102 if image recording is underway. If NO in step S 102 , the flow jumps to step S 105 ; otherwise, the pre-set mode is checked in step S 103 . If “no mode change” is set, the flow jumps to step S 105 ; if the image recording pause mode is set, the image recording mode is switched to the image recording pause mode in step S 104 . In step S 105 , the call reception mode is checked. If normal call reception is selected, the call reception informing function normally operates to inform the user of reception of an incoming call in step S 107 . On the other hand, if image recording call reception is selected, some call reception functions that may influence image recording are stopped, and a call reception message is displayed on the display in step S 106 . Then, the flow advances to step S 110 . FIG. 7 is a sequence chart upon receiving a call. Upon reception of a connection request from the calling party, the video camera issues a connection standby command to the calling party depending on the pre-set operation mode of the video camera. The video camera changes the mode or displays a call reception message if required depending on the pre-set contents of the call reception mode and video camera operation mode, and the current video camera operation mode, and issues a connection completion command. Then, normal connection proceeds in response to a connection completion acknowledge message from the calling party. FIG. 8 shows a display example on the display 214 in this embodiment. A screen 600 displays an image which is being recorded, and a window 601 shows information of the calling party. More specifically, the window 601 displays various kinds of information, i.e., “call reception” indicating that an incoming call is received, “important” indicating the importance level of a connection request, “meeting” indicating subject matter, and the face image of the calling party. Those information contents are displayed based on information appended to the connection request from the calling party. According to this embodiment, image recording can be satisfactorily done without being influenced by an unexpected call. In accordance with the pre-set modes, the operator can be appropriately informed of reception of an incoming call. Also, the operator can be adequately informed of the information contents. To restate, according to this embodiment, since the operator is adequately informed of reception of an incoming call in accordance with the operation mode of the video camera at the time of call reception, the telephone function and video camera function can be appropriately combined. Hence, a video camera with telephone having high operability can be provided. (Second Embodiment) FIG. 9 is a block diagram showing the arrangement of an image communication apparatus according to the second embodiment of the present invention. Referring to FIG. 9, reference numeral 401 denotes a lens; 402 , a stop of the lens; 403 , a motor for driving a zoom lens; 404 , a driving means for driving the zoom lens; 405 , a motor for driving the stop; 406 , a driving means for driving a stop mechanism; 407 , a motor for driving a focus lens; and 408 , a driving means for driving the focus lens. Reference numeral 409 denotes an image sensing element (CCD); 410 , a CDS/AGC circuit for sampling & holding a video signal output from the image sensing element, and performing AGC (auto gain control) of the video signal; 411 , an A/D converter for converting an analog signal into a digital signal; 412 , a camera signal processing circuit for processing luminance and color signals to obtain an appropriate video signal; and 413 , an image compression/expansion circuit for compressing/expanding an image. The image compression/expansion circuit 413 uses, for example, JPEG, H263, a DV format, or the like. Reference numeral 414 denotes a memory; 415 , a communication protocol circuit; 416 , a PHS transmitter/receiver; 417 , a microcomputer; 418 , a D/A converter for converting a digital signal into an analog signal; 419 , an antenna; 420 , a monitor (or a liquid crystal display device); 421 , a key discrimination circuit; and 422 , a ten-key pad for inputting a telephone number. Reference numeral 423 denotes a microphone; 424 , an audio signal processing circuit for processing an audio signal input from the microphone to obtain an appropriate signal; 425 , an A/D converter for converting an analog audio signal into a digital signal; 426 , an area setting pulse generation circuit; 427 , a gate circuit for setting an AF (auto-focus) area; and 429 , an AF evaluation value processing circuit. Reference numeral 431 denotes a telephone/camera mode selection switch; and 432 , a character generator. The operation of the above arrangement will be explained below. Incoming light from an object via the lens 401 is photoelectrically converted into an electrical signal by the image sensing element 409 . The electrical signal is processed by the camera signal processing circuit 412 to obtain a video signal. Furthermore, the video data is compressed by the image compression/expansion circuit 413 , and the compressed data is stored in the memory 414 . The data compressed by the image compression/expansion circuit 413 is processed by the communication protocol circuit 415 to obtain data according to a prescribed communication rule, and the processed data is transmitted from the antenna 419 via the PHS transmitter/receiver 416 . The data output from the camera signal processing circuit 412 is converted into an analog signal by the D/A converter 418 , and the analog signal is processed to be displayed on the monitor. After that, an image is output to the monitor. Moreover, image and audio radio signals transmitted from an external device are received by the PHS transmitter/receiver 416 via the antenna 419 , and image and audio data are obtained via the communication protocol circuit 415 . After that, the image data is. expanded by the image compression/expansion circuit 413 , and is output to the monitor via the D/A converter 418 . The microcomputer 417 controls the system of this apparatus, and performs various kinds of lens control (control of the focus lens, zoom lens, and stop), camera signal processing control, communication control, key control, and the like. The ten-key pad 422 is used for inputting the telephone number of the called party upon placing a call, and the discrimination circuit 421 discriminates the input key. The output from the discrimination circuit 421 is input to the microcomputer 417 , which executes a series of control processes for initiating a call. The same applies to an audio signal. That is, after a voice is input from the microphone 423 , the audio signal is processed by the audio signal processing circuit 424 , and is input to the communication protocol circuit 415 via the audio A/D converter 425 . After that, the audio signal is transmitted as a radio signal from the antenna 419 via the PHS transmitter/receiver as in the video signal. The characteristic feature of this embodiment will be explained below. An auto-focus signal is output from the camera signal processing circuit 412 , and an image signal is gated based on arbitrarily set area setting pulses output from the area setting pulse generation circuit 426 in the AF gate circuit 427 . More specifically, this block can designate an object to be focused on the screen. After that, the AF evaluation value processing circuit 429 appropriately processes the auto-focus signal, and outputs the processed signal to the microcomputer 417 . The microcomputer 417 outputs a signal for driving the lens to adjust the focus on the object to be focused. The timings of pulses generated by the area setting pulse generation circuit 426 are set by the ten-key pad 422 (#0 to #9). The ten-key pad 422 is also used for inputting a telephone number, and is one of the characteristic features of this embodiment. The operations and arrangement of the ten-key pad will be explained below. The ten-key pad 422 can be used in two modes by the telephone/camera mode selection switch 413 , as shown in FIG. 10 . When the user sets the telephone mode using the telephone/camera mode selection switch 431 to make a call, the ten-key pad 422 serves as keys used for inputting a telephone number, as in the telephone mode shown in FIG. 10 . More specifically, when the user inputs a telephone number using the ten-key pad 422 , the microcomputer 417 recognizes the telephone number via the key discrimination circuit 421 , and supplies a signal to the communication protocol circuit 415 to call a person corresponding to the input telephone number. After that, a call is placed to the person corresponding to the input telephone number from the antenna 419 via the PHS transmitter/receiver 416 . On the other hand, when the telephone/camera mode selection switch 431 is switched to the camera mode, the ten-key pad 422 serves: as keys for inputting an AF (auto-focus) set area, as shown in FIG. 10 . For example, when the user wants to set an area from the center toward the upper right corner, as shown in FIG. 10, he or she pushes key #3 of the ten-key pad 422 , and the key discrimination circuit 421 converts that input into a signal for discriminating that key #3 has been pressed. The microcomputer 417 processes data to set an upper right area, and sends that data to the area setting pulse generation circuit 426 , which generates pulses corresponding to the position of the received data. After that, the AF area gate circuit 427 gates an image signal on the basis of those pulses, i.e., passes only a focus signal within the set area. The AF evaluation value processing circuit 429 processes the focus signal to attain in-focus, and inputs the processed signal to the microcomputer 417 , which outputs data for driving the lens to adjust a focus. The focus lens driving circuit 408 drives the lens based on the received data. In this way, an object within the set area can be focused. The microcomputer 417 inputs area setting data to the character generator 432 , which generates an area setting frame to be displayed on a display circuit, and displays the frame on the monitor 420 . Likewise, to move the area setting frame around #5 as the center, the user pushes key #1 (upper left), #2 (upper), #3 (upper right) #4 (left), #5 (preset at the center), #6 (right), #7 (lower left), #8 (lower), or #9 (lower right) to adjust the focus on an object within the set area he or she selected, on the basis of the same operation principle as mentioned above. The monitor 420 displays the area setting frame at that time. As described above, according to this embodiment, since a common switch can efficiently provide two functions, the design of a compact portable device can be prevented from being impaired and its size can be prevented from increasing. (Third Embodiment) FIG. 11 is a block diagram showing the arrangement of an image communication apparatus according to the third embodiment of the present invention. The same reference numerals in the third embodiment shown in FIG. 11 denote the same parts as those in the second embodiment shown in FIG. 9, and a detailed description thereof will be omitted. Referring to FIG. 11, reference numeral 428 denotes an AE area gate circuit; and 430 , an AE evaluation value processing circuit. The characteristic feature of this embodiment will be explained below. An image exposure signal is output from the camera signal processing circuit 412 , and an image signal is gated based on arbitrarily set area setting pulses output from the area setting pulse generation circuit 426 in the AE gate circuit 428 . More specifically, this block can designate an object to be adjusted to have optimal exposure state on the screen. After that, the AE evaluation value processing circuit 430 appropriately processes the signal for obtaining an optimal exposure value, and outputs the processed signal to the microcomputer 417 . The microcomputer 417 outputs a signal for driving the stop so that the selected object has an optimal exposure value. The timings of pulses generated by the area setting pulse generation circuit 426 are set by the ten-key pad 422 (#0 to #9). The ten-key pad 422 is also used for inputting a telephone number, and is one of the characteristic features of this embodiment. The operations and arrangement of the ten-key pad will be explained below. The ten-key pad 422 can be used in two modes, as shown in FIG. 10 . When the user sets the telephone mode using the telephone/camera mode selection switch 431 to make a call, the ten-key pad 422 serves as keys used for inputting a telephone number, as in the telephone mode shown in FIG. 10 . More specifically, when the user inputs a telephone number using the ten-key pad 422 , the microcomputer 417 recognizes the telephone number via the key discrimination circuit 421 , and supplies a signal to the communication protocol circuit 415 to call a person corresponding to the input telephone number. After that, a call is placed to the person corresponding to the input telephone number from the antenna 419 via the PHS transmitter/receiver 416 . On the other hand, when the telephone/camera mode selection switch 431 is switched to the camera mode, the ten-key pad 422 serves as keys for inputting an AE (auto-iris) set area, as shown in FIG. 10 . For example, when the user wants to set an area from the center toward the upper right corner, as shown in FIG. 10, he or she pushes key #3 of the ten-key pad 422 , and the key discrimination circuit 421 converts that input into a signal for discriminating that key #3 has been pressed. The microcomputer 417 processes data to set an upper right area, and sends that data to the area setting pulse generation circuit 426 , which generates pulses corresponding to the position of the received data. After that, the AE area gate circuit 428 gates an image signal on the basis of those pulses, i.e., passes only an exposure signal within the set area. The AE evaluation value processing circuit 430 processes the exposure signal to obtain an optimal exposure value, and inputs the processed signal to the microcomputer 417 , which outputs data for driving the stop to obtain an optimal exposure value. The stop mechanism driving means 406 drives the stop 402 based on the received data. In this way, an optimal exposure value can be obtained with respect to an object within the set area. The microcomputer 417 inputs area setting data to the character generator 432 , which generates an area setting frame to be displayed on a display circuit, and displays the frame on the monitor 420 . Likewise, to move the area setting frame around #5 as the center, the user pushes key # 1 (upper left), #2 (upper), #3 (upper right) #4 (left), #5 (preset at the center), #6 (right), #7 (lower left), #8 (lower), or #9 (lower right) to obtain an optimal exposure value for an object within the set area he or she selected, on the basis of the same operation principle as mentioned above. The monitor 420 displays the area setting frame at that time. As described above, according to this embodiment, since a common switch can efficiently provide two functions, the design of a compact portable device can be prevented from being impaired and its size can be prevented from increasing. (Fourth Embodiment) FIG. 12 is a block diagram showing the arrangement of an image communication apparatus according to the fourth embodiment of the present invention. The same reference numerals in the fourth embodiment shown in FIG. 12 denote the same parts as those in the second embodiment shown in FIG. 9, and a detailed description thereof will be omitted. Referring to FIG. 12, reference numeral 433 denotes an image enlargement/reduction circuit. The characteristic feature of this embodiment will be explained below. An image signal is output from the camera signal processing circuit 412 , and the image enlargement/reduction circuit 433 electronically enlarges an image within a set area on the basis of area setting data output from the area setting pulse generation circuit 426 . The enlarged image is displayed on a display circuit via the camera signal processing circuit 412 and D/A converter 418 . The timings of pulses generated by the area setting pulse generation circuit 426 are set by the ten-key pad 422 (#0 to #9). The ten-key pad 422 is also used for inputting a telephone number, and is one of the characteristic features of this embodiment. The operations and arrangement of the ten-key pad will be explained below. The ten-key pad 422 can be used in two modes, as shown in FIG. 10 . When the user sets the telephone mode using the telephone/camera mode selection switch 431 to make a call, the ten-key pad 422 serves as keys used for inputting a telephone number, as in the telephone mode shown in FIG. 10 . More specifically, when the user inputs a telephone number using the ten-key pad 422 , the microcomputer 417 recognizes the telephone number via the key discrimination circuit 421 , and supplies a signal to the communication protocol circuit 415 to call a person corresponding to the input telephone number. After that, a call is placed to the person corresponding to the input telephone number from the antenna 419 via the PHS transmitter/receiver 416 . On the other hand, when the telephone/camera mode selection switch 431 is switched to the camera mode, the ten-key pad 422 serves as keys for arbitrarily inputting an area to be enlarged on the screen by the user, as shown in the camera mode of FIG. 10 . For example, when the user wants to enlarge an upper right object, as shown in FIG. 10, he or she pushes key #3 of the ten-key pad 422 , and the key discrimination circuit 421 converts that input into a signal for discriminating that key #3 has been pressed. The microcomputer 417 processes data to set an upper right area, and sends that data to the area setting pulse generation circuit 426 , which generates pulses corresponding to the position of the received data. After that, the image enlargement/reduction circuit 433 electronically enlarges an image within the area of that data. The enlarged image is displayed on the display circuit via the camera signal processing circuit 412 and D/A converter 418 . The microcomputer 417 inputs area setting data to the character generator 432 , which generates an area setting frame to be displayed on the display circuit, and displays the frame on the monitor 420 . Likewise, to move the area setting frame around #5 as the center, the user pushes key #1 (upper left), #2 (upper), #3 (upper right) #4 (left), #5 (preset at the center), #6 (right), #7 (lower left), #8 (lower), or #9 (lower right) to an area for an object to be enlarged, and the object within that area can be displayed as an enlarged image, on the basis of the same operation principle as mentioned above. Also, the set frame is displayed on the monitor 420 . Also, reduction is done based on the same operation principle as in enlargement. (Fifth Embodiment) FIG. 13 is a block diagram showing the arrangement of an image communication apparatus according to the fifth embodiment of the present invention. The same reference numerals in the fifth embodiment shown in FIG. 13 denote the same parts as those in the second embodiment shown in FIG. 9, and a detailed description thereof will be omitted. The characteristic feature of this embodiment will be explained below. The microcomputer 417 controls a plurality of functions. For example, the microcomputer 417 controls white balance set, shutter, and fade as camera functions, and teleconversion, wipe, scroll, and the like as digital effect functions, and executes a function selected by external operation. As a method of allowing the user to easily operate such multiple functions, menu setup is available. This embodiment is directed to improving the functions of operation switches to attain menu setups, and will be explained in detail with reference to FIGS. 13 and 14. The ten-key pad 422 can be used in two modes by a telephone/menu mode selection switch 431 , as shown in FIG. 14 . When the user sets the telephone mode using the telephone/menu mode selection switch 431 to make a call, the ten-key pad 422 serves as keys used for inputting a telephone number, as in the telephone mode shown in FIG. 14 . More specifically, when the user inputs a telephone number using the ten-key pad 422 , the microcomputer 417 recognizes the telephone number via the key discrimination circuit 421 , and supplies a signal to the communication protocol circuit 415 to call a person corresponding to the input telephone number. After that, a call is placed to the person corresponding to the input telephone number from the antenna 419 via the PHS transmitter/receiver 416 . On the other hand, when the telephone/menu mode selection switch 431 is switched to the menu mode, a plurality of functions available are displayed on the screen, and the user selects a function to be executed using the ten-key pad 422 , as shown in the menu mode of FIG. 14 . For example, when the user wants to execute “title”, and if the cursor is currently located at “scroll”, the user pushes key #6 of the menu-key pad (ten-key pad) 422 , and then pushes key #2 to select “title”. That is, the user can move the cursor upward, leftward, downward, and rightward by pushing keys #2, #4, #8, and #6 of the ten-key pad 422 to select a function he or she wants to designate. At this time, when the user pushes a given key on the ten-key pad 422 , data of the selected item is input from the microcomputer 417 to the character generator 432 via the key discrimination circuit 421 , and the character generator 432 generates display data to be displayed on the display circuit, thus making a display on the monitor 420 . More specifically, the user can select and execute a desired function while observing displayed menu items, and switches are easy to operate since they have the same layout as that of menu items displayed. Since common switches are efficiently and selectively used in the TEL and menu modes, such arrangement is very effective for a portable device which must attain a size reduction. As described above, according to the second to fifth embodiments, in a portable device which has camera and communication functions like a videophone, a compact image communication apparatus which has a function of allowing the user to adjust the focus on an arbitrary object to be sensed on the screen, and can provide many functions without increasing the number of switches and impairing design, can be provided. Also, a low-cost image communication apparatus which is easy to operate since it adopts an efficient switch layout can be provided. Furthermore, a compact image communication apparatus which has a function of allowing the user to obtain an optimal exposure value on an arbitrary object to be sensed on the screen, and can provide many functions without increasing the number of switches and impairing design, can be provided. Moreover, a compact image communication apparatus which has a function of allowing the user to enlarge or reduce an arbitrary object to be sensed on the screen, and can provide many functions without increasing the number of switches and impairing design, can be provided. In addition, a compact image communication apparatus which allows the user to select and execute a function while observing menu items displayed, is easy to operate since switches and displayed items have a common layout, and can provide many functions without increasing the number of switches and impairing design, can be provided. To restate, according to the second to fifth embodiments, a low-cost image communication apparatus, which is easy to operate since it adopts an efficient switch layout, while providing many functions, can be provided. (Sixth Embodiment) FIG. 15 is a block diagram showing the arrangement of an image communication apparatus according to the sixth embodiment of the present invention. Referring to FIG. 15, reference numeral 501 denotes a lens; 502 , a stop of the lens; 503 , a motor for driving a zoom lens; 504 , a driving means for driving the zoom lens; 505 , a motor for driving the stop; 506 , a driving means for driving a stop mechanism; 507 , a motor for driving a focus lens; and 508 , a driving means for driving the focus lens. Reference numeral 509 denotes an image sensing element (CCD); 510 , a CDS/AGC circuit for sampling & holding a video signal output from the image sensing element, and performing AGC (auto gain control) of the video signal; 511 , an A/D converter for converting an analog signal into a digital signal; 512 , a camera signal processing circuit for processing luminance and color signals to obtain an appropriate video signal; and 513 , an image compression/expansion circuit for compressing/expanding an image. The image compression/expansion circuit 513 uses, for example, JPEG, H263, a DV format, or the like. Reference numeral 514 denotes a memory; 515 , a communication protocol circuit; 516 , a PHS transmitter/receiver; 517 , a microcomputer; 518 , a D/A converter for converting a digital signal into an analog signal; 519 , an antenna; 520 , a monitor (or a liquid crystal display device); 521 , a key discrimination circuit; and 522 , a ten-key pad for inputting a telephone number. Reference numeral 523 denotes a microphone; 524 , an audio signal processing circuit for processing an audio signal input from the microphone to obtain an appropriate signal; 525 , an A/D converter for converting an analog audio signal into a digital signal; 526 , an area setting pulse generation circuit; 527 , a gate circuit for setting an AF (auto-focus) area; 529 , an AF evaluation value processing circuit; and 531 , a selection switch for selecting a telephone function upon placing a call. The operation of the above arrangement will be explained below. Incoming light from an object via the lens 501 is photoelectrically converted into an electrical signal by the image sensing element 509 . The electrical signal is processed by the camera signal processing circuit 512 to obtain a video signal. Furthermore, the video data is compressed by the image compression/expansion circuit 513 , and the compressed data is stored in the memory 514 . The data compressed by the image compression/expansion circuit 513 is processed by the communication protocol circuit 515 to obtain data according to a prescribed communication protocol, and the processed data is transmitted from the antenna 519 via the PHS transmitter/receiver 516 . The data output from the camera signal processing circuit 512 is converted into an analog signal by the D/A converter 518 , and the analog signal is processed to be displayed on the monitor. After that, an image is output to the monitor. Moreover, image and audio radio signals transmitted from an external device are received by the PHS transmitter/receiver 516 via the antenna 519 , and image and audio data are obtained via the communication protocol circuit 515 . After that, the image data is expanded by the image compression/expansion circuit 513 , and is output to the monitor via the D/A converter 518 . The microcomputer 517 controls the system of this apparatus, and performs various kinds of lens control (control of the focus lens, zoom lens, and stop), camera signal processing control, communication control, key control, and the like. The ten-key pad 522 is used for inputting the telephone number of the called party upon placing a call, and the discrimination circuit 521 discriminates the input key. The output from the discrimination circuit 521 is input to the microcomputer 517 , which executes a series of control processes for initiating a call. The same applies to an audio signal. That is, after a voice is input from the microphone 523 , the audio signal is processed by the audio signal processing circuit 524 , and is input to the communication protocol circuit 515 via the audio A/D converter 525 . After that, the audio signal is transmitted as a radio signal from the antenna 519 via the PHS transmitter/receiver as in the video signal. In this embodiment, an image can be sensed by the camera, and a function of adjusting the focus on an object at an arbitrary position on the screen is available as one of functions that can be used upon image sensing. The function will be explained below. An auto-focus signal is output from the camera signal processing circuit 512 , and an image signal is gated based on arbitrarily set area setting pulses output from the area setting pulse generation circuit 526 in the AF gate circuit 527 . More specifically, this block can designate an object to be focused on the screen. After that, the AF evaluation value processing circuit 529 appropriately processes the auto-focus signal, and outputs the processed signal to the microcomputer 517 . The microcomputer 517 outputs a signal for driving the lens to adjust the focus on the object to be focused. The timings of pulses generated by the area setting pulse generation circuit 526 are set by the ten-key pad 522 (#0 to #9). The ten-key pad 522 is also used for inputting a telephone number, and is one of the characteristic features of this embodiment. The operation and arrangement of the ten-key pad 522 will be explained below. The telephone mode execution switch 531 is used for selecting the telephone function upon placing a call. When the telephone mode execution switch 531 has been pressed, the ten-key pad 522 has a telephone mode function shown in FIG. 16; when the switch 531 is not pressed, the ten-key pad 522 has a camera mode function shown in FIG. 16 . When the user has pressed the telephone mode execution switch 531 to place a call, the ten-key pad 522 serves as keys for inputting a telephone number, as shown in the telephone mode of FIG. 16 . When the user inputs a telephone number using the ten-key pad 522 , the microcomputer 517 recognizes the telephone number via the key discrimination circuit 521 , and supplies a signal to the communication protocol circuit 515 to call a person corresponding to the input telephone number. After that, a call is placed to the person corresponding to the input telephone number from the antenna 519 via the PHS transmitter/receiver 516 . When the user does not make a call or is talking to another person, the ten-key pad 522 serve as keys for inputting an AF (auto-focus) set area, as shown in the camera mode in FIG. 16 . For example, when the user wants to set an area from the center toward the upper right corner, as shown in FIG. 16, he or she pushes key #3 of the ten-key pad 522 , and the key discrimination circuit 521 converts that input into a signal for discriminating that key #3 has been pressed. The microcomputer 517 processes data to set an upper right area, and sends that data to the area setting pulse generation circuit 526 , which generates pulses corresponding to the position of the received data. After that, the AF area gate circuit 527 gates an image signal on the basis of those pulses, i.e., passes only a focus signal within the set area. The AF evaluation value processing circuit 529 processes the focus signal to attain in-focus, and inputs the processed signal to the microcomputer 517 , which outputs data for driving the lens to adjust the focus. The focus lens driving circuit 508 drives the lens based on the received data. In this way, an object within the set area can be focused. Likewise, to move the area setting frame around # 5 as the center, the user pushes key #1 (upper left), #2 (upper), #3 (upper right) #4 (left), #5 (preset at the center), #6 (right), #7 (lower left), #8 (lower), or #9 (lower right) to adjust the focus on an object within the set area he or she selected, on the basis of the same operation principle as mentioned above. The monitor 520 displays the area setting frame at that time. As described above, the characteristic feature of this embodiment is to efficiently and selectively use common switches in two functions (one of which is the telephone mode function, and the other is the camera mode function). The characteristic feature of this embodiment will be explained in more detail below with reference to the flow chart in FIG. 17 . All operations in this flow chart are processed by the microcomputer 517 . When the flow starts in step S 601 , the user turns on the power switch of the apparatus in step S 602 . Upon power ON, camera functions such as an image sensing system, AF function, ZOOM function, AF frame movement setup function, and the like, are enabled in step S 603 . In step S 604 , the control waits until the user selects the telephone mode. If the user has pressed the telephone mode execution switch 531 to place a call, the telephone mode function is enabled. In step S 605 , some of the camera functions are turned off or disabled. After the telephone function mode is selected, the ten-key pad 522 serves as switches for inputting a telephone number to be called, and the user inputs the telephone number to be called in step S 606 . In step S 607 , transmission to the called party is executed. It is checked in step S 608 if a voice communication with the called party has been established. If YES in step S 608 , some of telephone mode functions are automatically turned off in step S 609 . For instance, the telephone number input function is turned off. After that, the camera mode function is turned on again in step S 610 to enable the image sensing system and AF and ZOOM functions. The operation then ends in step S 612 . More specifically, as can be seen from the aforementioned flow chart, in this embodiment, two functions are assigned to common switches: one is the camera mode (image sensing mode) function, and the other is the telephone mode function. Upon depression of the telephone mode execution switch 531 , the telephone mode function is enabled, and the ten-key pad 522 serves as telephone number input switches. After that, if a voice communication with a partner has been confirmed, the telephone mode function is automatically switched to the camera mode (image sensing mode) function, and the ten-key pad 522 serves as AF frame movement setup switches. Only a required function is automatically enabled when it is required in place of always enabling two functions, so as to attain power savings. Also, since two functions are attained using common switches, a compact, low-cost image communication apparatus can be provided. FIG. 18 shows another example of common switches used in two functions in addition to the aforementioned ten-key pad. This switch is a rotary switch. As shown in FIG. 18, the switch serves as one for selecting one of telephone numbers registered in advance in the telephone mode. When the user has confirmed a voice communication with a partner, the switch is automatically switched to the one for the camera mode. In FIG. 18, the switch serves as a zoom switch. (Seventh Embodiment) FIG. 19 is a block diagram showing the arrangement of an image communication apparatus according to the seventh embodiment of the present invention. The same reference numerals in the seventh embodiment shown in FIG. 19 denote the same parts as those in the sixth embodiment shown in FIG. 15, and a detailed description thereof will be omitted. The seventh embodiment comprises a character generator 532 unlike the sixth embodiment. The arrangement and contents as the characteristic feature of this embodiment will be explained below. As in the sixth embodiment described above, incoming light from an object via the lens 501 is photoelectrically converted into an electrical signal by the image sensing element 509 . The electrical signal is processed by the camera signal processing circuit 512 to obtain a video signal. Furthermore, the video data is compressed by the image compression/expansion circuit 513 , and the compressed data is stored in the memory 514 . The data compressed by the image compression/expansion circuit 513 is processed by the communication protocol circuit 515 to obtain data according to a prescribed communication rule, and the processed data is transmitted from the antenna 519 via the PHS transmitter/receiver 516 . The data output from the camera signal processing circuit 512 is converted into an analog signal by the D/A converter 518 , and the analog signal is processed to be displayed on the monitor. After that, an image is output to the monitor. Moreover, image and audio radio signals transmitted from an external device are received by the PHS transmitter/receiver 516 via the antenna 519 , and image and audio data are obtained via the communication protocol circuit 515 . After that, the image data is expanded by the image compression/expansion circuit 513 , and is output to the monitor via the D/A converter 518 . The microcomputer 517 controls the system of this apparatus, and performs various kinds of lens control (control of the focus lens, zoom lens, and stop), camera signal processing control, communication control, key control, and the like. The ten-key pad 522 is used for inputting the telephone number of the called party upon placing a call, and the discrimination circuit 521 discriminates the input key. The output from the discrimination circuit 521 is input to the microcomputer 517 , which executes a series of control processes for placing a call. The same applies to an audio signal. That is, after a voice is input from the microphone 523 , the audio signal is processed by the audio signal processing circuit 524 , and is input to the communication protocol circuit 515 via the audio A/D converter 525 . The audio signal is then transmitted as a radio signal from the antenna 519 via the PHS transmitter/receiver as in the video signal. In this embodiment, an image can be sensed by the camera, and a function of adjusting the focus on an object at an arbitrary position on the screen is available as one of functions that can be used upon image sensing. In this case, the operations that have already been described in the sixth embodiment are done. As described in the sixth embodiment, the characteristic feature of the sixth and seventh embodiments is to efficiently and selectively use common switches in two functions (one of which is the telephone mode function, and the other is the camera mode function). The contents of that characteristic feature has already been described with reference to the flow chart in FIG. 17 . Furthermore, in the seventh embodiment, the display in the telephone mode can be automatically switched between those shown in FIGS. 16 and 18. When the user has pressed the telephone mode execution switch 531 to place a call, the microcomputer 517 outputs data to the character generator 532 to display the telephone number and called party's name on the monitor 520 . When the user does not make a call or when it is confirmed that a voice communication with a partner has been established upon placing a call, the camera mode is set, and an AF frame movement setup frame or a zoom state (FIG. 18) is displayed on the monitor 520 . As has been described above, according to the sixth and seventh embodiments, in a portable device which has camera and communication functions like a videophone, a compact image communication apparatus which can efficiently and selectively use the camera and telephone functions based on the outputs from the telephone mode execution switch and a voice communication detection circuit for determining if a voice communication has been established, so as to attain power savings, and selectively use common switches in two functions (camera and telephone functions) to provide many functions without increasing the number of switches and impairing design, can be provided. Also, a low-cost image communication apparatus which is easy to operate since it adopts an efficient switch layout can be provided. The present invention is not limited to the above embodiments and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, to apprise the public of the scope of the present invention the following claims are made.

This invention has as its object to appropriately inform the user of reception of an incoming call in accordance with the operation mode of a video camera upon arrival of call. To achieve this object, an apparatus has a telephone and video camera in a single housing, and comprises a device for muting a ringing tone during image sensing by the video camera.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a drive device that drives a movable part on which, for example, an image sensor of a camera is attached. [0003] 2. Description of the Related Art [0004] A device which is provided in a photographing device such as a digital camera and removes dust particles attached to the camera's image sensor and its cover is proposed. [0005] United States Published Patent Application Publication Number 2005-0264656 A discloses a drive device which vibrates attached dust particles by striking a movable part against a fixed part for a constant interval so as to dislodge the dust particles attached to an image sensor and its cover with the impact of the strike. [0006] However, dust particles vary in weight, but only a constant vibrational frequency is generated by striking a movable part against a fixed part for a constant interval. Therefore, some dust particles may not be removed from an image sensor and its cover by the impact of the strike. SUMMARY OF THE INVENTION [0007] An object of the present invention is to provide a drive device which efficiently removes dust particles from an image sensor and its cover. [0008] A drive device is provided having a movable part, a fixed part, and a drive part. The fixed part is provided within a movement range of the movable part. The drive part drives the movable part in a first direction so as to strike said fixed part. The drive part drives the movable part to and fro along the first direction alternately for different time intervals so as to strike the fixed part. BRIEF DESCRIPTION OF THE DRAWINGS [0009] The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which: [0010] FIG. 1 is a perspective view of the image-capturing device according to the embodiment of the present invention; [0011] FIG. 2 is a front view of the image-capturing device; [0012] FIG. 3 is a block diagram of the image-capturing device; [0013] FIG. 4 is a flowchart showing a main process of the image-capturing device; [0014] FIG. 5 is a flowchart showing an interrupting process; [0015] FIG. 6 is a flowchart showing a dust-removal process; [0016] FIG. 7 shows the trajectory of the movable part in the y-direction during the dust-removal process; [0017] FIG. 8 schematically shows the trajectory of the movable part watching an imaging device from the lens side; and [0018] FIG. 9 shows the trajectory of the movable part in the x-direction during the dust-removal process. DESCRIPTION OF THE PREFERRED EMBODIMENTS [0019] The present invention is described below with reference to the embodiment shown in the drawings. FIGS. 1 to 3 show the construction of an image-capturing apparatus 1 which comprises a drive device according to the present embodiment. In this embodiment, the photographing apparatus 1 is a digital camera. A photographing optical system, such as a camera lens 67 etc., that captures an optical image on a photographing surface of the image sensor of the photographing apparatus 1 has an optical axis LX. In order to explain the orientation of the embodiment, an x-direction (the first direction), a y-direction (the second direction), and a z-direction are defined (refer to FIG. 1 ). The x-direction is in the horizontal plane and perpendicular to the optical axis LX. The y-direction is perpendicular to the optical axis LX and the x-direction. The z-direction is parallel to the optical axis LX and perpendicular to both the x-direction and the y-direction. The positive x-direction is the XP-direction; the negative x-direction is the XM-direction. The positive y-direction is the YP-direction; the negative y-direction is the YM-direction. The positive x-direction is the XP-direction; the negative x-direction is the XM-direction. The positive y-direction is the YP-direction; the negative y-direction is the YM-direction. [0020] The photographing apparatus 1 comprises a power button 11 which is used to turn on or off the power of the photographing apparatus, a release button 13 , an anti-shake button 14 , an LCD monitor 17 , a mirror-aperture-shutter unit 18 , a DSP 19 , a CPU 21 , an AE (automatic exposure) unit 23 , an AF (automatic focus) unit 24 , an anti-shake unit 30 , imaging unit 39 a, and a camera lens 67 . These components perform the imaging function. [0021] Whether the power switch 11 a is in the ON state or the OFF state is determined by the state of the power button 11 , so that the ON and OFF states of the photographing apparatus 1 correspond to the ON and OFF states of the power switch 11 a. The photographic subject image is captured as an optical image through the camera lens 67 by the imaging unit 39 a, and the captured image is displayed on the LCD monitor 17 . The photographic subject image can be observed through the optical finder (not depicted). [0022] After the power button 11 is depressed, putting the photographing apparatus 1 in the ON state, a dust-removal operation is performed in a first period (320 ms). [0023] When the release button 13 is partially depressed by the operator, the photometric switch 12 a changes to the ON state so that the photometric operation, the AF-sensing operation, and the focusing operation are performed. When the release button 13 is fully depressed by the operator, the release switch 13 a changes to the ON state so that the imaging operation by the imaging unit 39 a (the imaging apparatus) is performed, and the image is captured and stored. [0024] The mirror-aperture-shutter unit 18 is connected to port P 7 of the CPU 21 and performs an UP/DOWN operation of the mirror (a mirror-up operation and a mirror-down operation), an OPEN/CLOSE operation of the aperture, and an OPEN/CLOSE operation of the shutter according to the ON state of the release switch 13 a. [0025] The DSP 19 is connected to the imaging unit 39 , and port P 9 of the CPU 21 . Based on a command from the CPU 21 , the DSP 19 performs calculations such as image processing, etc., on the image signal obtained by the imaging operation of the imaging unit 39 a. [0026] The CPU 21 is a control apparatus that controls each part of the photographing apparatus 1 regarding the imaging operation, the dust-removal operation, and the anti-shake operation (i.e., the image stabilizing operation). The anti-shake operation includes both the movement of the movable part 30 a and a position-detection operation. Furthermore, the CPU 21 stores the value of anti-shake parameter IS, the value of release state parameter RP, the value of dust-removal state parameter GP, and the value of dust-removal time parameter CNT. [0027] Anti-shake parameter IS indicates whether the photographing apparatus 1 is in the anti-shake mode. When the anti-shake parameter IS equals one, the photographing apparatus 1 is in the anti-shake mode; when it equals zero, the photographing apparatus 1 is not in the anti-shake mode. [0028] The value of the release state parameter RP changes with respect to the release sequence operation. When the release sequence operation is performed, the value of the release state parameter RP is set to one (refer to steps S 24 to S 31 in FIG. 4 ); and when the release sequence operation is finished, the value of the release state parameter RP is set (reset) to zero (refer to steps S 13 and S 32 in FIG. 4 ). [0029] The dust-removal state parameter GP indicates whether the dust-removal operation is finished. The value of the dust-removal state parameter GP is set to one because the dust-removal operation may be considered underway from the moment immediately after the photographing apparatus 1 is set to the ON state until the first period (320 ms) has elapsed (refer to step S 14 in FIG. 4 ). [0030] The value of the dust-removal state parameter GP is set to zero because the dust-removal operation may be considered to be finished from the moment when the first period (320 ms) has elapsed after the photographing apparatus 1 is set to the ON state (refer to step S 16 in FIG. 4 ). [0031] The dust-removal time parameter CNT is used for measuring the length of time the dust-removal operation is underway. The initial value of the dust-removal time parameter CNT is substituted by zero. While the dust-removal operation is being performed, the value of the dust-removal time parameter CNT is increased by one at every time interval of 1 ms (refer to step S 701 in FIG. 6 ). [0032] The CPU 21 moves the movable part 30 a to a predetermined initial position in the dust-removal operation before the anti-shake operation. This operation is named the centering operation (refer to step S 84 in FIG. 7 ). In this embodiment, the predetermined position is the center of the movement range (where the coordinate values in the x-direction and in the y-direction are both 0). [0033] Then, the center of mass of the movable part 30 a is kept at a certain position relative to the x-direction by the CPU 21 . The XP-side of the movable part 30 a is driven in the YP-direction of the y-direction, and the XM-side of the movable part 30 a is driven in the YM-direction at the same time. Therefore, the movable part 30 a swings relative to a given axis, so that the XP-end of the YP-side of the movable part 30 a strikes the upper boundary 34 a of the movable range and the XM-end of the YM-side of the movable part 30 a strikes the lower boundary 34 b of the movable range. [0034] Then, the XP-side of the movable part 30 a is driven in the YM-direction of the y-direction, and the XM-side is simultaneously driven in the YP-direction, while the movable part 30 a is kept at a certain position concerning to the x-direction. Therefore, the movable part 30 a swings in the direction opposite to last swing, so that the XM-end of the YP-side strikes the upper boundary 34 a of the movable range and the XP-end of the YM-side strikes the lower boundary 34 b of the movable range. After repeating these processes, the dust-removal operation ends. [0035] The dust particles on the imaging unit 39 a of the movable part 30 a (the image sensor and the low-pass filter) are removed by the shock of the impact of the movable part 30 a against the boundary of said movable range. After the dust-removal operation is completed, the anti-shake operation begins. [0036] Next, the CPU 21 stores the values of a first digital angular velocity signal Vxn, a second digital angular velocity signal Vyn, a first digital angular velocity VVxn, a second digital angular velocity VVyn, a first digital displacement angle Bxn, a second digital displacement angle Byn, the coordinate of position Sn in the x-direction, Sxn; the coordinate of position Sn in the y-direction, Syn; the first driving force, Dxn; the second driving force, Dyn; the coordinate of position Pn after A/D conversion in the x-direction, pdxn; the coordinate of position Pn after A/D conversion in the y-direction, pdyn; a first subtraction value, exn; a second subtraction value, eyn; a first proportional coefficient, Kx; a second proportional coefficient, Ky; a sampling cycle θ of the anti-shake operation; a first integral coefficient, Tix; a second integral coefficient, Tiy; a first differential coefficient, Tdx; and a second differential coefficient, Tdy. [0037] The AE unit 23 (an exposure calculating unit) performs the photometric operation and calculates the photometric values, based on the subject being photographed. The AE unit 23 also calculates the aperture value and the duration of the exposure, with respect to the photometric values, both of which are needed for imaging. The AF unit 24 performs the AF-sensing operation and the corresponding focusing operation, both of which are also needed for imaging. In the focusing operation, the camera lens 67 is moved along the optical axis LX. [0038] The anti-shake part (the anti-shake apparatus) of the photographing apparatus 1 comprises an anti-shake button 14 , an anti-shake switch 14 a, an LCD monitor 17 , a CPU 21 , an angular velocity detection unit 25 , a driver circuit 29 , an anti-shake unit 30 , a hall-element signal-processing unit 45 (a magnetic-field change-detecting element), and the camera lens 67 . [0039] When the anti-shake button 14 is depressed by the operator, the anti-shake switch 14 a is set to the ON state. When the anti-shake switch 14 a is in the ON state, the photographing apparatus 1 is in the anti-shake mode, and the anti-shake parameter IS is set to one (IS =1). When the anti-shake switch 14 a is not in the ON state, the photographing apparatus 1 is in the non-anti-shake mode, and the anti-shake parameter IS is set to zero (IS=0). In the anti-shake mode, the anti-shake operation is executed. In the anti-shake operation, the angular velocity detection unit 25 and the anti-shake unit 30 are driven for the second period independent of other operation, such as the photometry operation. In this embodiment, the value of the predetermined time interval is set to 1 ms. [0040] The CPU 21 controls the various output commands corresponding to the input signals from these switches. The port P 12 of the CPU 21 receives a 1-bit digital signal indicating whether the photometric switch 12 a is in the ON state or the OFF state. The port P 13 of the CPU 21 receives a 1-bit digital signal indicating whether the release switch 13 a is in the ON state or the OFF state. The port P 14 of the CPU 21 receives a 1-bit digital signal indicating whether the anti-shake switch 14 a is in the ON state or the OFF state. The AE unit 23 , the AF unit 24 , and the LCD monitor 17 are respectively connected to port P 4 , P 5 and P 6 of the CPU 21 for I/O. [0041] Next, the details of the angular velocity detection unit 25 , the driver circuit 29 , the anti-shake unit 30 , and the hall-element signal-processing unit 45 are described. [0042] The angular velocity detection unit 25 has a first angular velocity sensor 26 a, a second angular velocity sensor 26 b, a first high-pass filter circuit 27 a, a second high-pass filter circuit 27 b, a first amplifier 28 a and a second amplifier 28 b. [0043] The first angular velocity sensor 26 a detects the angular velocity of a rotary motion (the yawing) of the photographing apparatus 1 about the axis of the y-direction, i.e., it detects the velocity component in the x-direction of the angular velocity of the photographing apparatus 1 . The first angular velocity sensor 26 a is a gyro sensor that detects the yaw angular velocity. [0044] The second angular velocity sensor 26 b detects the angular velocity of a rotary motion (the pitch) of the photographing apparatus 1 about the axis of the x-direction i.e., detects the velocity component in the y-direction of the angular velocity of the photographing apparatus 1 . The second angular velocity sensor 26 b is a gyro sensor that detects a pitch angular velocity. [0045] The first high-pass filter circuit 27 a reduces a low-frequency component of the signal output from the first angular velocity sensor 26 a, because the low-frequency component of the signal output from the first angular velocity sensor 26 a includes signal elements that are based on a null voltage and panning motion, neither of which are related to camera shake. The second high-pass filter circuit 27 b reduces a low-frequency component of the signal output from the second angular velocity sensor 26 b, because the low-frequency component of the signal output from the second angular velocity sensor 26 b includes signal elements that are based on a null voltage and panning motion, neither of which are related to camera shake. The processes performed by the first and second high-pass filter circuit 27 a and 27 b are analog high-pass filter processes. [0046] The first amplifier 28 a amplifies a signal related to the yawing angular velocity, whose low-frequency component has been reduced, and outputs the analog signal to the port A/DO of the CPU 21 as a first angular velocity vx. The second amplifier 28 b amplifies a signal relating to the pitch angular velocity, whose low-frequency component has been reduced, and outputs the analog signal to the port A/D 1 of the CPU 21 as a second angular velocity vy. [0047] The reduction of the low-frequency signal component is a two-step process; the primary part of the analog high-pass filter process is performed first by the first and second high-pass filter circuits 27 a and 27 b, followed by the secondary part of the digital high-pass filter process that is performed by the CPU 21 . The cut-off frequency of the secondary part of the digital high-pass filter process is higher than that of the primary part of the analog high-pass filter process. In the digital high-pass filter process, the value of a time constant (a first high-pass filter time constant hx and a second high-pass filter time constant hy) can be easily changed. [0048] The supply of electrical power to the CPU 21 and all parts of the angular velocity detection unit 25 begins after the power switch 11 a is set to the ON state (i.e., the main power supply is set to the ON state). The calculation of a camera-shake value begins after the power switch 11 a is set to the ON state and the dust-removal operation is finished. [0049] The CPU 21 converts the first and second angular velocities vx and vy, which are respectively input to the ports A/D 0 and A/D 1 , to a first and second digital angular velocity signals Vxn and Vyn. It then calculates first and second digital angular velocities VVxn and VVyn by reducing a low-frequency component of the first and second digital angular velocity signals Vxn and Vyn (the digital high-pass filter process) because the low-frequency component of the first and second digital angular velocity signals Vxn and Vyn include signal elements that are based on a null voltage and panning motion, neither of which are related to camera shake. Moreover, it calculates a camera-shake displacement angle (the first and second digital displacement angles Bxn and Byn) by integrating the first and second digital angular velocities VVxn and VVyn (the integration process). [0050] The CPU 21 and the angular velocity detection unit 25 use a function to calculate the camera-shake value. [0051] “n” is an integer greater than zero and indicates the length of time (ms) from the commencement of the timer interruption process, (t=0; refer to step S 12 in FIG. 4 ), to the point when the latest anti-shake operation is performed (t=n). [0052] In the digital high-pass filter process regarding the x-direction, the first digital angular velocity VVxn is calculated by dividing the summation of the first digital angular velocities VVx 0 to VVxn−1 (calculated by the timer interruption process before the 1 ms predetermined time interval; i.e., before the latest anti-shake operation was performed), by the first high-pass filter time constant hx, and then subtracting the resulting quotient from the first digital angular velocity signal Vxn (VVxn=Vxn−(ΣVVxn−1)÷hx). In the digital high-pass filter process regarding the y-direction, the second digital angular velocity VVyn is calculated analogously to VVxn to give(VVyn=Vyn−(ΣVVyn−1)÷hy). [0053] In this embodiment, the angular velocity detection operation in (a portion of) the timer interruption process includes the processing by the angular velocity detection unit 25 and the process of inputting the first and second angular velocities vx and vy from the angular velocity detection unit 25 to the CPU 21 . [0054] In the integration process regarding the x-direction, the first digital displacement angle Bxn is calculated by summing from the first digital angular velocity VVx 0 at the point when the timer interruption process commences (t=0; refer to step S 12 in FIG. 4 ), to the first digital angular velocity VVxn at the point when the latest anti-shake operation is performed (t=n; Bxn=ΣVVxn). [0055] Similarly, in the integration process regarding the y-direction, the second digital displacement angle Byn is calculated by summing from the second digital angular velocity VVy 0 at the point when the timer interruption process commences, to the second digital angular velocity VVyn at the point when the latest anti-shake operation is performed (Byn=ΣVVyn). [0056] The CPU 21 calculates the position Sn where the imaging unit 39 a (the movable part 30 a ) should be moved, corresponding to the camera-shake value (the first and second digital displacement angles Bxn and Byn) that is calculated for the x-direction and the y-direction on the basis of a position conversion coefficient zz (a first position conversion coefficient zx for the x-direction and a second position conversion coefficient zy for the y-direction). [0057] The coordinate of position Sn in the x-direction is defined as Sxn, and in the y-direction as Syn. The movement of the movable part 30 a, which includes the imaging unit 39 a, is performed using electromagnetic force, and is described later. [0058] The driving force Dn drives the driver circuit 29 in order to move the movable part 30 a to the position Sn. The coordinate of the driving force Dn in the x-direction is defined as the first driving force Dxn (after D/A conversion: a first PWM duty dx). The coordinate of the driving force Dn in the y-direction is defined as the second driving force Dyn (after D/A conversion: a second PWM duty dy). A first driving coil 31 a is driven according to the value of the first driving force Dxn. A second driving coil 32 a is driven according to the second driving force Dyn. [0059] The first PWM duty dx is the duty ratio of the driving pulse corresponding to the first driving force Dxn. The second PWM duty dy is the duty ratio of the driving pulse corresponding to the second driving force Dyn. [0060] The value of second driving force Dyn is represented by +DD or −DD. +DD indicates that the movable part 30 a is driven in the positive y-direction (YP-direction), i.e., towards the upper end of the fixed part 30 b. −DD indicates that the movable part 30 a is driven in the negative y-direction (YM-direction), i.e., towards the bottom end of the fixed part 30 b. [0061] However, the position Sn, where the imaging unit 39 a (the movable part 30 a ) should be moved in the first period (320 ms) for the dust-removal operation before the anti-shake operation is performed, is set to “a” value that does not correspond to the camera shake value (refer to step S 704 in FIG. 6 ). [0062] For example, the position Sn is set on the center of the fixed part 30 b in the “a” trajectory of the dust-removal operation. Therefore, the movable part 30 a is set on the center of the fixed part 30 b. In the “b” to “d” trajectories of the dust-removal operation, the x-direction component of the position Sn is set at a certain value, but in the y-direction, only the PWM duty is set and the y-direction component of the position Sn is not set. Thus, the movable part 30 a is moved towards the top or bottom of the fixed part 30 b by constant force, and strikes it. [0063] In a positioning operation along the x-direction, the coordinate of position Sn in the x-direction is defined as Sxn, and is the product of the latest first digital displacement angle Bxn and the first position conversion coefficient zx (Sxn=z×Bxn). [0064] In a positioning operation along the y-direction, the coordinate of position Sn in the y-direction is defined as Syn, and is the product of the latest second digital displacement angle Byn and the second position conversion coefficient zy (Syn=zy×Byn). [0065] The anti-shake unit 30 corrects for camera shake by repeatedly moving the imaging unit 39 a to position Sn. This stabilizes the photographing subject image displayed on the imaging surface of the image sensor during the exposure time when the anti-shake operation is performed (IS=1). [0066] The anti-shake unit 30 has a fixed part 30 b that forms the boundary of the movement range of the movable part 30 a, and the movable part 30 a which includes the imaging unit 39 a and can be moved on the xy plane. The movement range is wider than the shake-correction area in which the movable part 30 a is moved during the anti-shake operation. [0067] During the exposure time when the anti-shake operation is not performed (IS=0), the movable part 30 a is held in the predetermined position. The predetermined position is the center of the movement range. [0068] In the first period (320 ms), after the photographing apparatus 1 is set to the ON state, the movable part 30 a is driven to the predetermined position (i.e., the center of the movement range). Next, the movable part 30 a is driven against the boundary of the movement range in the y-direction. [0069] Otherwise (except for the first period and the exposure time), the movable part 30 a is not driven. [0070] The anti-shake unit 30 does not have a fixed-positioning mechanism that maintains it in a fixed position when it is not being driven (i.e., the drive OFF state). [0071] The driving of the movable part 30 a of the anti-shake unit 30 , including the movement to a predetermined fixed position, is performed by the electromagnetic force of the coil and magnetic units for driving, by action of the driver circuit 29 which has first PWM duty dx input from the PWM 0 of the CPU 21 and second PWM duty dy input from the PWM 1 of the CPU 21 . [0072] The movable part 30 a of the anti-shake unit 30 is driven by the electromagnetic force created by the coil and magnet units. The electromagnetic force is generated when the driver circuit 29 energizes the coil units. The driver circuit 29 energizes a first driving coil 31 a when receiving first PWM duty dx output by the PWM 0 of the CPU 21 , and a second driving coil 32 a when receiving second PWM duty dy output by the PWM 1 . [0073] The position Pn of the movable part 30 a, either before or after the movement effected by the driver circuit 29 , is detected by the hall element 44 a and the hall-element signal-processing unit 45 . [0074] Information regarding the first coordinate of the detected position Pn in the x-direction, in other words the first detected position signal px, is input to the A/D converter A/D 2 of the CPU 21 (refer to ( 2 ) in FIG. 6 ). The first detected position signal px is an analog signal that is converted to a digital signal by the A/D converter A/D 2 (A/D conversion). Through the A/D conversion, analog px becomes digital pdxn. [0075] Similarly, regarding the y-direction, py is input to the A/D converter A/D 3 of the CPU 21 . Through the A/D conversion, analog py is becomes digital pdyn. [0076] The PID (Proportional Integral Differential) control procedure calculates the first and second driving forces Dxn, Dyn on the basis of the coordinate data for the detected position Pn (pdxn, pdyn) and the position Sn (Sxn, Syn) following movement. [0077] The calculation of the first driving force Dxn is based on the first subtraction value exn, the first proportional coefficient Kx, the sampling cycle θ, the first integral coefficient Tix, and the first differential coefficient Tdx (Dxn=Kx×{exn+θ÷Tix×Σexn+Tdx÷θ×x(exn−exn−1)}). The first subtraction value exn is calculated by subtracting the first coordinate of the detected position Pn in the x-direction after the A/D conversion, pdxn, from the coordinate of position Sn in the x-direction, Sxn (exn=Sxn−pdxn). [0078] The calculation of the second driving force Dyn is based on the second subtraction value eyn, the second proportional coefficient Ky, the sampling cycle θ, the second integral coefficient Tiy, and the second differential coefficient Tdy (Dyn=Ky×{eyn+θ÷Tiy×Σeyn+Tdy÷θ×(eyn−eyn−1)}). The second subtraction value eyn is calculated by subtracting the second coordinate of the detected position Pn in the y-direction after the A/D conversion, pdyn, from the coordinate of position Sn in the y-direction, Syn (eyn=Syn−pdyn). [0079] The value of the sampling cycle θ is set to the predetermined time interval of 1 ms (the second period). [0080] The movable part 30 a is driven to the position Sn (Sxn, Syn) by the anti-shake operation of the PID control procedure, when the photographing apparatus 1 is set to the anti-shake mode (IS=1) by the setting of the anti-shake switch 14 a to the ON state. The position Sn is determined by the PID control procedure comprised in the anti-shake operation. [0081] When the anti-shake parameter IS is zero, the PID control procedure not comprised in the anti-shake operation is performed so that the movable part 30 a is moved to the center of the movement range (the predetermined position). [0082] In the dust-removal operation, from the point when the photographing apparatus 1 is set to the ON state until the anti-shake operation commences, the movable part 30 a is first moved to the center of the movement range. After that, the movable part 30 a is driven according to the processes described herein before. [0083] The movable part 30 a has a coil unit for driving that is comprised of a first driving coil 31 a, a second driving coil 32 a, an imaging unit 39 a that has the image sensor, and a hall element 44 a acting as a magnetic-field change-detecting element. In the first embodiment, the image sensor is a CCD; however, the image sensor may be another image sensor such as a CMOS etc. [0084] The rectangular form of the imaging surface of the image sensor has two sides parallel to the x-direction and two sides parallel to the y-direction that are shorter than those of the x-direction. Accordingly, the movement range of the movable part 30 a in the x-direction is greater than in the y-direction. [0085] The fixed part 30 b has a magnetic unit for driving that is comprised of a first position-detecting and driving magnet 411 b, a second position-detecting and driving magnet 412 b, a first position-detecting and driving yoke 431 b, and a second position-detecting and driving yoke 432 b. [0086] The fixed part 30 b movably supports the movable part 30 a in the x-direction and in the y-direction. [0087] The fixed part 30 b has a buffer member that absorbs the shock at the point of contact the movable part 30 a (at the boundary of the movement range). [0088] The hardness of the buffer member is chosen such that the part making contact, such as the movable part 30 a, is not damaged by the shock of the impact, but any dust on the movable part 30 a will be removed by the shock of the impact with the buffer member. [0089] In the first embodiment, the buffer member is attached to the fixed part 30 b; however, the buffer member may be attached to the movable part 30 a. [0090] When the movable part 30 a is positioned at the center of its movement range in both the x-direction and the y-direction, the center of the image sensor intersects the optical axis LX of the camera lens 67 , and the full imaging range of the image sensor may be utilized. [0091] The rectangle shape, which is the form of the imaging surface of the image sensor, has two diagonal lines. In the first embodiment, the center of the image sensor is at the intersection of these two diagonal lines. [0092] The first driving coil 31 a, the second driving coil 32 a, and the hall element 44 a are attached to the movable part 30 a. [0093] The first driving coil 31 a is formed in a sheet and a spiral and has magnetic field lines in the y-direction, thus creating the first electromagnetic force for moving the movable part 30 a which includes the first driving coil 31 a, in the x-direction. [0094] The first electromagnetic force occurs on the basis of the current direction of the first driving coil 31 a and the magnetic-field direction of the first position-detecting and driving magnet 411 b. [0095] The second driving coil 32 a is formed in a sheet and a spiral and has magnetic field lines in the x-direction, thus creating the second electromagnetic force for moving the movable part 30 a which includes the second driving coil 32 a in the y-direction. [0096] The second electromagnetic force occurs on the basis of the current direction of the second driving coil 32 a and the magnetic-field direction of the second position-detecting and driving magnet 412 b. [0097] The first and second driving coils 31 a and 32 a are connected to the driver circuit 29 which drives the first and second driving coils 31 a and 32 a through a flexible circuit board (not depicted). The first PWM duty dx is input to the driver circuit 29 from the PWM 0 of the CPU 21 . Similarly, the second PWM duty dy is input to the driver circuit 29 from the PWM 1 of the CPU 21 . The driver circuit 29 supplies power to the first driving coil 31 a corresponding to the value of the first PWM duty dx, and to the second driving coil 32 a that corresponding to the value of the second PWM duty dy in order to drive the movable part 30 a. [0098] The first and second position-detecting and driving yoke 431 b and 432 b are made of a soft, magnetic material, and provided on the fixed part 30 b. [0099] The first position-detecting and driving yoke 431 b prevents the magnetic-field of the first position-detecting and driving magnet 411 b from dissipating to the surroundings, and raises the magnetic-flux density between the first position-detecting and driving magnet 411 b and the first driving coil 31 a, and between the first position-detecting and driving magnet 411 b and the horizontal hall element hh. [0100] Similarly, the second position-detecting and driving yoke 432 b prevents the magnetic-field of the second position-detecting and driving magnet 412 b from dissipating to the surroundings, and raises the magnetic-flux densities between the second position-detecting and driving magnet 412 b and the second driving coil 32 a, between the second position-detecting and driving magnet 412 b and the first vertical hall element hv. [0101] The first position-detecting and driving magnet 411 b is attached to the movable part side of the fixed part 30 b, where the first position-detecting and driving magnet 411 b faces the first driving coil 31 a and the horizontal hall element hh in the z-direction. In detail, the first position-detecting and driving magnet 411 b is attached to the first position-detecting and driving yoke 431 b. The first position-detecting and driving yoke 431 b is attached to the fixed part 30 b on the side of the movable part 30 a in the z-direction. The N pole and S pole of the first position-detecting and driving magnet 411 b are arranged in the x-direction. [0102] Similarly, the second position-detecting and driving magnet 412 b is attached to the movable part side of the fixed part 30 b, where the second position-detecting and driving magnet 412 b faces respectively the second driving coil 32 a and the vertical hall element hv in the z-direction. In detail, the second position-detecting and driving magnet 412 b is attached to the second position-detecting and driving yoke 432 b. The second position-detecting and driving yoke 432 b is respectively attached to the fixed part 30 b on the side of the movable part 30 a in the z-direction. The N pole and S pole of the second position-detecting and driving magnet 412 b are arranged in the y-direction. [0103] The hall element 44 a comprises a horizontal hall element hh which detects the coordinate of the position Pn of the movable part 30 a in the x-direction, and a vertical hall element hv which detects the coordinate of the XM-side of the movable part 30 a in the y-direction. Each hall element are single-axis units that contain magneto-electric converting elements (magnetic-field change-detecting elements) utilizing the Hall Effect. The horizontal hall element hh outputs the first detected position signal px which indicates the present position Pn of the movable part 30 a. Similarly, the vertical hall element hv respectively output the second detected position signal py. [0104] The horizontal hall element hh is attached to the movable part 30 a where the horizontal hall element hh faces the first position-detecting and driving magnet 411 b in the z-direction. Similarly, the vertical hall element hv is attached to the movable part 30 a where is faces the second position-detecting and driving magnet 412 b in the z-direction. [0105] When the center of the image sensor is intersecting the optical axis LX, it is desirable to have the horizontal hall element hh positioned on the hall element 44 a facing an intermediate area between the N pole and S pole of the first position-detecting and driving magnet 411 b in the x-direction, as viewed from the z-direction. In this position, the horizontal hall element hh utilizes the maximum range in which an accurate position-detecting operation can be performed based on the linear output change (linearity) of the single-axis hall element. Similarly, when the center of the image sensor is intersecting the optical axis LX, it is desirable to have the vertical hall element hv positioned on the hall element 44 a facing an intermediate area between the N pole and S pole of the second position-detecting and driving magnet 412 b in the y-direction, as viewed from the z-direction. [0106] The hall-element signal-processing unit 45 has a first hall-element signal-processing circuit 450 , and a second hall-element signal-processing circuit 460 . [0107] The first hall-element signal-processing circuit 450 detects a horizontal potential difference x 10 between the output terminals of the horizontal hall element hh. The horizontal potential difference x 10 is detected with an output signal of the horizontal hall element hh. The first hall-element signal-processing circuit 450 outputs the first detected position signal px, which specifies the first coordinate of the position Pn of the movable part 30 a in the x-direction, to the A/D converter A/D 2 of the CPU 21 , on the basis of the horizontal potential difference x 10 . [0108] Similarly, the second hall-element signal-processing circuit 460 detects a vertical potential difference y 10 between the output terminals of the vertical hall element hv. The vertical potential difference y 10 is detected with an output signal of the vertical hall element hv. After that, the second hall-element signal-processing circuit 460 outputs the second detected position signal py to the A/D converter A/D 3 of the CPU 21 . [0109] Next, the main process of the photographing apparatus 1 in the first embodiment is explained using the flowchart of FIG. 4 . [0110] When the photographing apparatus 1 is set to the ON state, electrical power is supplied to the angular velocity detection unit 25 so that the angular velocity detection unit 25 is set to the ON state in step S 11 . [0111] In step S 12 , the timer interruption process at the predetermined time interval (1 ms) commences. In step S 13 , the value of the release state parameter RP is set to zero. The detail of the timer interruption process is explained later using the flowchart of FIG. 5 . [0112] In step S 14 , the value of the dust-removal state parameter GP is set to one; the value of the dust-removal time parameter CNT is set to zero; and the channel parameter is set to a. [0113] In step S 15 , it is determined whether the value of the dust-removal time parameter CNT is greater than 320 ms. Step S 15 is provided to wait until the end of the timer interruption process. The dust-removal time parameter CNT is the time that is need so that the timer interruption process is finished. In this embodiment, in consideration of the completion time of the timer interruption process and individual differences in anti-shake units 30 , 320 ms is used. [0114] In step S 15 , it is determined whether the value of the dust-removal time parameter CNT is greater than 320 ms. When it is determined that the value of the dust-removal time parameter CNT is greater than 320 ms, the process continues to step S 16 ; otherwise, the process in step S 15 is repeated. [0115] In step S 16 , the value of the dust-removal state parameter GP is set to 0. [0116] In step S 17 , it is determined whether the photometric switch 12 a is set to the ON state. When it is determined that the photometric switch 12 a is set to the ON state, the process continues to step S 18 ; otherwise, the process in step S 17 is repeated. [0117] In step S 18 , it is determined whether the anti-shake switch 14 a is set to the ON state. When it is determined that the anti-shake switch 14 a is not set to the ON state, the value of the anti-shake parameter IS is set to zero in step S 19 ; otherwise, the value of the anti-shake parameter IS is set to one in step S 20 . [0118] In step S 21 , the AE sensor of the AE unit 23 is driven, the photometric operation is performed, and the aperture value and exposure time are calculated. [0119] In step S 22 , the AF sensor and the lens control circuit of the AF unit 24 are driven to perform the AF sensing and focusing operations, respectively. [0120] In step S 23 , it is determined whether the release switch 13 a is set to the ON state. When the release switch 13 a is not set to the ON state, the process returns to step S 17 and the process in steps S 17 to S 22 is repeated; otherwise, the process continues to step S 24 and the release-sequence operation commences. [0121] In step S 24 , the value of the release state parameter RP is set to one. In step S 25 , the mirror-up operation and the aperture closing operation corresponding to the aperture value that is either preset or calculated, are performed by the mirror-aperture-shutter unit 18 . [0122] After the mirror-up operation is finished, the opening operation of the shutter (the movement of the front curtain of the shutter) commences in step S 26 . [0123] In step S 27 , the exposure operation, or in other words the electrical charge accumulation of the image sensor (CCD etc.), is performed. After the exposure time has elapsed, the closing operation of the shutter (the movement of the rear curtain of the shutter), the mirror-down operation, and the opening operation of the aperture are performed by the mirror-aperture-shutter unit 18 in step S 28 . [0124] In step S 29 , the electrical charge which has accumulated in the image sensor during the exposure time is read. In step S 30 , the CPU 21 communicates with the DSP 19 so that the imaging process is performed based on the electrical charge read from the image sensor. The image, on which the image process is performed, is stored in the memory of the photographing apparatus 1 . In step S 31 , the image that is stored in the memory is displayed on the LCD monitor 17 . In step S 32 , the value of the release state parameter RP is set to zero, and the release sequence operation is finished. After that, the process then returns to step S 17 . In other words, the photographing apparatus 1 is set to a state where the next imaging operation can be performed. [0125] Next, the timer interruption process, which commences in step S 12 in FIG. 4 and is performed at every 1 ms time interval, is described with reference to the flowchart in FIG. 5 . [0126] When the timer interruption process commences, it is determined whether the value of the dust-removal state parameter GP is set to one in step S 50 . When it is determined that the value of the dust-removal state parameter GP is set to one, the process continues to step S 51 ; otherwise, the process proceeds directly to step S 52 . [0127] In step S 51 , the dust-removal process is performed. The detail of the dust-removal process is explained later using the flowchart of FIG. 6 . [0128] In step S 52 , the first angular velocity vx, which is output from the angular velocity detection unit 25 , is input to the A/D converter A/D 0 of the CPU 21 and converted to the first digital angular velocity signal Vx n . The second angular velocity vy, which is also output from the angular velocity detection unit 25 , is input to the A/D converter A/D 1 of the CPU 21 and converted to the second digital angular velocity signal Vy n (the angular velocity detection process). [0129] The low frequencies of the first and second digital angular velocity signals Vx n and Vy n are reduced in the digital high-pass filter process (the first and second digital angular velocities VVx n and VVy n ). [0130] In step S 53 , it is determined whether the value of the release state parameter RP is set to one. When it is determined that the value of the release state parameter RP is not set to one, the driving control of the movable part 30 a is set to the OFF state. In other words, the anti-shake unit 30 is set to a state where the driving control of the movable part 30 a is not performed in step S 54 ; otherwise, the process proceeds directly to step S 55 . [0131] In step S 55 , the first and second detected position signals px and py are input to the CPU 21 thorough the A/D converters A/D 2 and A/D 3 , and also converted to digital signals. The CPU 21 determines the present position Pn (pdxn, pdyn) of the movable part 30 a with the input signals. [0132] In step S 56 , it is determined whether the value of the anti-shake parameter IS is zero. When it is determined that the value of the anti-shake parameter IS is zero, (in other words when the photographing apparatus is not in anti-shake mode), the position Sn (Sxn, Syn) where the movable part 30 a (the imaging unit 39 a ) should be moved is set to the center of the movement range of the movable part 30 a, in step S 57 . When it is determined that the value of the anti-shake parameter IS is not zero (IS=1), (in other words when the photographing apparatus is in anti-shake mode), the position Sn (Sxn, Syn) where the movable part 30 a (the imaging unit 39 a ) should be moved is calculated on the basis of the first and second angular velocities vx and vy, in step S 58 . [0133] In step S 59 , the first driving force Dxn (the first PWM duty dx), and the second driving force Dyn (the second PWM duty dyl) of the driving force Dn that moves the movable part 30 a to the position Sn are calculated on the basis of the position Sn (Sxn, Syn) that was determined in step S 57 or step S 58 , and the present position Pn (pdxn, pdyn). [0134] In step S 60 , the first driving coil unit 31 a is driven by applying the first PWM duty dx to the driver circuit 29 , and the second driving coil unit 32 a is driven by applying the second PWM duty dy to the driver circuit 29 , so that the movable part 30 a is moved to position Sn (Sxn, Syn). [0135] The process of steps S 59 and S 60 is an automatic control calculation that is used with the PID automatic control for performing general proportional, integral, and differential calculations. [0136] Next, the dust-removal process, which commences in step S 51 in FIG. 5 , is explained using the flowchart in FIGS. 6 to 9 . [0137] When the dust-removal process commences, the value of the dust-removal time parameter CNT is increased by one in step S 701 . [0138] In step S 702 , the hall element 44 a detects the position of the movable part 30 a, and the first and second detected position signals px and py are calculated by the hall-element signal-processing unit 45 . The first detected position signal px is then input to the A/D converter A/D 2 of the CPU 21 and converted to a digital signal pdx n , while the second detected position signal py is input to the A/D converter A/D 3 of the CPU 21 and also converted to digital signal, whereupon the CPU 21 determines the present position Pn (pdx n , pdy n ) of the movable part 30 a with the input signal. [0139] In step S 703 , it is determined whether the value of the dust-removal time parameter CNT is less than or equal to 65 ms. In the case that the value of the dust-removal time parameter CNT is less than or equal to 65 ms, steps S 704 to S 706 are commenced. In the case that the value of the dust-removal time parameter CNT is not less than or equal to 65 ms, the process proceeds to step S 710 . [0140] Steps S 704 to S 706 process the “a” trajectory which drives the movable part 30 a to the center of the fixed part 30 b. [0141] In the step S 704 , the position Sn (Sxn, Syn) where the movable part 30 a (the imaging unit 39 a ) should be moved is set to the center of the movement range of the movable part 30 a. [0142] In step S 705 , the driving force Dn that moves the movable part 30 a is calculated using the position Sn (Sxn, Syn) that was determined in step S 704 according to the present position Pn (pdxn, pdyn). This calculation is the same as the one in step S 59 in the timer interruption process. [0143] In step S 706 , the movable part 30 a is moved by executing the same process as in step S 60 in the timer interruption process. Then, the dust-removal process ends, and the process returns to the timer interruption process (subroutine return). [0144] The timer interruption process is executed every millisecond (the second periods). Therefore, the dust-removal process is also repeatedly executed until the dust-removal state parameter GP is set to zero in step S 16 of the main process. [0145] When the dust-removal process commences again, the value of the dust-removal time parameter CNT is increased by one, making it two, in step S 701 . Then, steps S 702 and S 703 are executed. In the step S 703 , it is determined whether the value of the dust-removal time parameter CNT is less than or equal to 65 ms. At this point, the value of the dust-removal time parameter CNT is two. Therefore, the process proceeds to step S 704 , and then ends after commencing steps S 704 to S 706 (subroutine return). After that, the dust-removal process is executed again in the timer interruption process. [0146] Steps S 701 to S 706 are repeatedly executed until the dust-removal time parameter CNT becomes greater than 65 ms. In the case that the dust-removal time parameter CNT becomes greater than 65 ms in step S 703 , the process proceeds to step S 710 . Note that the movable part 30 a is placed in the center of the fixed part 30 b. [0147] The maximum time interval which is needed to move the movable part 30 a from the present position to the center of the fixed part 30 b is 65 ms. In other words, the time interval calculated by adding the average time interval which is needed to move the movable part 30 a from the corner to the center of the fixed part 30 b and the error time interval of the individual difference of the anti-shake unit 30 is 65 ms. Therefore, the threshold value of the dust-removal time parameter CNT is set to 65 ms. In the case the dust-removal time parameter CNT is less than or equal to 65 ms, there is a possibility that movable part 30 a has not yet arrived the center of fixed part 30 b. When the dust-removal time parameter CNT is greater than 65 ms, the movable part 30 a is in the center of fixed part 30 b. [0148] In step S 710 , it is determined whether the dust-removal time parameter CNT is less than or equal to 115 ms. In the case that the dust-removal time parameter CNT is less than or equal to 115 ms, steps S 711 to S 715 is commenced. In the case that the dust-removal time parameter CNT is not less than or equal to 115 ms, the process proceeds to step S 720 . [0149] Next, the process of steps S 711 to S 714 is described. Steps S 711 to S 714 process the “b” trajectory which strikes the movable part 30 a against the lower boundary of the fixed part 30 b. [0150] In step S 711 , the value of the second PWM duty dyl is set to −DD. The value DD, i.e., the absolute value |+DD| and |−DD| is set so that the acceleration of the movable part 30 a at the point in time when the movable part 30 a is moved to and struck against the boundary of the movement range of the movable part 30 a is increased to the degree where the dust on the movable part 30 a can be removed by the shock of the impact. [0151] In step S 712 , the coordinate of position Sn in the x-direction, Sxn, where the movable part 30 a should be moved in the x-direction, is set to the center of the movement range of the movable part 30 a in the x-direction. [0152] In step S 713 , the first driving force Dxn (the first PWM duty dx) is calculated on the basis of the coordinate of position Sn in the x-direction, Sxn, determined in step S 712 , and the coordinate of the present position Pn in the x-direction, pdxn. The first driving force Dxn, i.e., the driving force Dn which moves the movable part 30 a in the x-direction, is needed to move the movable part 30 a by providing current to the first driving coil unit 31 a. [0153] In step S 714 , the first and second driving coil units 31 a and 32 a are respectively driven by applying the first and second PWM duties dx and dy to the driver circuit 29 , so that the movable part 30 a is moved. The movable part 30 a is moved towards the center of the movable range along the x-direction, and fixed on the center of the movable range along the x-direction (refer to FIG. 9 ). Additionally, the movable part 30 a is moved towards the bottom of the fixed part 30 b, i.e., along the positive y-direction. After that, the process ends (subroutine return), and the dust-removal process is executed again in the timer interruption process. [0154] When the dust-removal process commences again, the value of the dust-removal time parameter CNT is increased by one so as to become 67 , in step S 701 . Then, steps S 702 , S 703 , and S 710 to S 714 are executed. Thus, steps S 701 to S 703 and S 701 to S 714 are executed until the value of the dust-removal time parameter CNT is greater than 115 ms. In the case that the value of the dust-removal time parameter CNT is greater than 115 ms in step S 710 , the process proceeds to step S 720 . [0155] By iterating steps S 701 to S 714 , the movable part 30 a is fixed so as to contact the bottom side of the fixed part 30 b after the movable part 30 a strikes the bottom side of the fixed part 30 b. [0156] Next, the reason why the threshold value of the dust-removal time parameter CNT is set to 115 ms, is described. The maximum time interval from the moment that the movable part 30 a starts moving from the present position to the moment that bounce from the collision of the movable part 30 a against the top or bottom of the fixed part 30 b settles is 50 ms. Specifically, the maximum time interval calculated by adding: the average time interval from the moment that the movable part 30 a starts moving at the center of the fixed part 30 b to the moment that it arrives at the top or bottom of the fixed part 30 b, the error time interval of the individual difference of the anti-shake unit 30 , and the time interval that bounce created by striking the movable part 30 a against the fixed part 30 b is settled, is 50 ms. The threshold value 115 ms is calculated by adding the maximum time interval 50 ms and the time interval from the moment that the dust-removal process starts to the moment that the “b” trajectory is started. In the case the dust-removal time parameter CNT is less than or equal to 115 ms, there is a possibility that movable part 30 a has not yet reached top or bottom side of fixed part 30 b. When the dust-removal time parameter CNT is greater than 115 ms, the movable part 30 a is at the top or bottom side of fixed part 30 b. [0157] In the next step, S 720 , it is determined whether the dust-removal time parameter CNT is less than or equal to 165 ms. In the case that the dust-removal time parameter CNT is less than or equal to 165 ms, steps S 721 , and S 712 to S 714 are commenced. In the case that the dust-removal time parameter CNT is not less than or equal to 165 ms, the process proceeds to step S 730 . [0158] Next, the process of steps S 721 , and S 712 to S 714 is described. These steps process the “c” trajectory which strikes the movable part 30 a against the bottom of the fixed part 30 b. [0159] In step S 721 , the value of the second PWM duty dy is set to +DD. [0160] Processes similar to those described above commence in steps S 712 to S 714 , so that the movable part 30 a is returned to the center of the movable range along the x-direction after it is moved towards the center of the movable range along the x-direction (refer to FIG. 9 ). Additionally, the movable part 30 a is moved towards the top of the fixed part 30 b. After that, the process ends (subroutine return), and the dust-removal process is executed again in the timer interruption process. [0161] When the dust-removal process commences again, the value of the dust-removal time parameter CNT is increased by one so as to become 117 ms, in step S 701 . Then, steps S 702 , S 703 , S 720 , S 721 , and S 712 to S 714 are executed. Thus, these steps are iterated until the value of the dust-removal time parameter CNT is greater than 165 ms. In the case that the value of the dust-removal time parameter CNT is greater than 165 ms in step S 720 , the process proceeds to step S 730 . [0162] By executing these steps, the movable part 30 a is fixed so as to contact the top side of the fixed part 30 b after the movable part 30 a strikes the top side of the fixed part 30 b. [0163] The reason why the dust-removal time parameter CNT is set to 165 ms is omitted because it was described above. In the case the dust-removal time parameter CNT is less than or equal to 165 ms, there is a possibility that movable part 30 a has not yet arrived at the top side of fixed part 30 b. In the case the dust-removal time parameter CNT is greater than 165 ms, the movable part 30 a is fixed so as to contact the top side of fixed part 30 b. [0164] In next step S 730 , it is determined whether the dust-removal time parameter CNT is less than or equal to 215 ms. In the case that the dust-removal time parameter CNT is less than or equal to 215 ms, steps S 711 to S 714 are commenced. In the case that the dust-removal time parameter CNT is not less than or equal to 215 ms, the process proceeds to step S 740 . [0165] The descriptions concerning steps S 711 to S 714 are omitted because they are described above. Steps S 711 to S 714 process the “d” trajectory which strikes the movable part 30 a against the bottom side of the fixed part 30 b. By executing these steps, the movable part 30 a is fixed so as to contact the bottom side of the fixed part 30 b after the movable part 30 a strikes the bottom side of the fixed part 30 b. [0166] The reason why the dust-removal time parameter CNT is set 215 ms is omitted because it is described above. In the case the dust-removal time parameter CNT is less than or equal to 215 ms, there is a possibility that movable part 30 a is not yet put in the bottom side of fixed part 30 b. In the case the dust-removal time parameter CNT is greater than 215 ms, the movable part 30 a is fixed so as to contact the bottom side of fixed part 30 b. [0167] In next step S 740 , it is determined whether the dust-removal time parameter CNT is less than or equal to 245 ms. In the case that the dust-removal time parameter CNT is less than or equal to 245 ms, steps S 721 and S 712 to S 714 are commenced. Therefore, the “c 2 ” trajectory which strikes the movable part 30 a against the top side of the fixed part 30 b is processed. [0168] The time interval from the moment of completion of the “d 1 ” trajectory to the moment of the completion of the “c 2 ” trajectory is set to 30 ms which is shorter than the 50 ms is omitted in the “d 1 ” trajectory. The vibration frequency of the movable part 30 a can be changed by shortening the time interval from the moment of completion of the “d 1 ” trajectory to the moment of the completion of the “c 2 ” trajectory. It is necessary to shake the movable part 30 a at a vibration frequency corresponding to the weight of the dust particles so as to efficiently remove them from an image sensor and its cover. By changing the vibrational frequency of the movable part 30 a, the drive device can remove not only dust particles which can be removed by 30 ms of vibration, but also dust particles which can be removed by 50 ms of vibration frequency. [0169] In the next step, S 750 , it is determined whether the dust-removal time parameter CNT is less than or equal to 275 ms. In the case that the dust-removal time parameter CNT is less than or equal to 275 ms, steps S 711 to S 714 are commenced. Therefore, the “d 2 ” trajectory which strikes the movable part 30 a against the bottom side of the fixed part 30 b is processed so that the movable part 30 a contacts the bottom side of the fixed part 30 b. The time interval from the moment of completion of the “c 2 ” trajectory to the moment of the completion of the “d 2 ” trajectory is set 30 ms. In the case the dust-removal time parameter CNT is not less than or equal to 275 ms, the process proceeds to step S 760 . [0170] In next step S 760 , it is determined whether the dust-removal time parameter CNT is less than or equal to 290 ms. In the case that the dust-removal time parameter CNT is less than or equal to 290 ms, steps S 721 and S 712 to S 714 are commenced. Therefore, the “c 3 ” trajectory which strikes the movable part 30 a against the top side of the fixed part 30 b is processed, so that the movable part 30 a contacts the top side of the fixed part 30 b. In the case the dust-removal time parameter CNT is not less than or equal to 290 ms, the process proceeds to step S 770 . [0171] The time interval from the moment of completion of the “d 2 ” trajectory to the moment of the completion of the “c 3 ” trajectory is set to 15 ms, which is shorter than the 30 ms taken in the “d 2 ” trajectory. According to change the vibration frequency of the movable part 30 a, the drive device can remove not only dust particles which can be removed by 15 ms of vibration, but also dust particles which can be removed by 50 ms and 30 ms of vibration. [0172] In next step S 770 , it is determined whether the dust-removal time parameter CNT is less than or equal to 305 ms. In the case that the dust-removal time parameter CNT is less than or equal to 305 ms, steps S 711 to S 714 are commenced. The time interval from the moment of completion of the “c 3 ” trajectory to the moment of the completion of the “d 3 ” trajectory is set 15 ms. Therefore, the “d 3 ” trajectory which strikes the movable part 30 a against the bottom side of the fixed part 30 b is processed, so that the movable part 30 a contacts the bottom side of the fixed part 30 b. In the case the dust-removal time parameter CNT is not less than or equal to 305 ms, the process proceeds to step S 780 . [0173] In the next step S 780 , the movable part 30 a is in the drive OFF state. Therefore, driving force is not applied to the movable part 30 a, so that the movable part 30 a settled on the bottom of the fixed part 30 b by gravity. [0174] According to this embodiment, the vibrational frequency of the movable part 30 a may be changed, so that the drive device can effectively remove dust particles of various weights. [0175] Additionally, the time interval required to execute the dust-removal process may be shortened because the time interval from the moment of striking the movable part 30 a against the fixed part 30 b to the moment of moving the movable part 30 a the next time shortens. [0176] Note that the dust-removal time parameter CNT is increased in steps, or in random order (in regular order if the dust-removal time parameter CNT is shortened in steps), in the present embodiment. [0177] Note that the impact of the movable part 30 a and the fixed part 30 b is not limited to three times, but may be any number of times greater than or equal to one. In that case, steps S 710 to S 770 are executed according to the number of impacts. [0178] The movable part 30 a does not strike the top and the bottom of the fixed part 30 b alternately, but may strike repeatedly either the top or bottom of the fixed part 30 b. [0179] In the dust-removal operation, the movable part 30 a may be held at the center in the y-direction and moved in the x-direction. The movable range of the movable part 30 a in the x-direction is longer than in the y-direction. [0180] Furthermore, the position to which the movable part 30 a is moved when the dust-removal operation commences is not limited to the center of the movement range of the movable part 30 a, but may be any position where the movable part 30 a does not make contact with the boundary of the movement range of the movable part 30 a. [0181] Moreover, it is explained that the hall element is used for position detection as the magnetic-field change-detecting element. However, another detection element, an MI (Magnetic Impedance) sensor such as a high-frequency carrier-type magnetic-field sensor; a magnetic resonance-type magnetic-field detecting element; or an MR (Magneto-Resistance effect) element may be used for position detection purposes. When one of either the MI sensor, the magnetic resonance-type magnetic-field detecting element, or the MR element is used, the information regarding the position of the movable part 30 a can be obtained by detecting the magnetic-field change, similar to using the hall element. [0182] Although the embodiment of the present invention has been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in the art without departing from the scope of the invention. [0183] The present disclosure relates to subject matter contained in Japanese Patent Application No. 2008-055969 (filed on Mar. 6, 2008), which is expressly incorporated herein, by reference, in its entirety.

A drive device is provided having a movable part, a fixed part, and a drive part. The fixed part is provided within a movement range of the movable part. The drive part drives the movable part in a first direction so as to strike said fixed part. The drive part drives the movable part to and fro along the first direction alternately for different time intervals so as to strike the fixed part.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a national stage entry under 35 U.S.C. 371 of International Application No. PCT/SE2009/051469, filed 21 Dec. 2009, designating the United States. This application claims foreign priority under 35 U.S.C. 119 and 365 to Swedish Patent Application No. 0802677-5, filed 30 Dec 2008. The complete contents of these applications are incorporated herein by reference. TECHNICAL FIELD OF THE INVENTION The present invention relates to biopolymer based barrier coating compositions with improved properties for providing barrier coatings on cellulose based substrates, e.g. paper and paperboard, as well as paper and paperboard provided with such coating. It also relates to a method for preparing a biopolymer based barrier coating composition and to a method for preparing cellulose based substrates with barrier properties. BACKGROUND OF THE INVENTION Barrier coatings are used in paper and paperboard packaging to provide barrier properties to paper and paperboard by reducing or eliminating the permeability of gases through the material and/or the absorption of liquids in the fiber structure. Barrier coatings are required to prevent the egress from the package of flavors, aromas and other ingredients of the packaged product as well as to prevent the ingress into the package of oxygen, moisture, grease and other contaminants that might deteriorate the quality of the packaged product. Oxygen and water vapour are the gases for which barriers are normally tested but the barriers are useful for other gases as well, including carbon dioxide. Various coatings have been applied to paper or paperboard substrates to provide composite materials that may be used for various purposes. Polymer dispersions or latexes have become attractive in recent years as a replacement for petroleum-based plastics for use as barrier materials. Barrier dispersions can be applied using conventional coating techniques, both online and off-line. Common applications of dispersion coatings are corrugated board, sacks, disposables, frozen and chilled food cartons, ream wrappings for copy paper, electronic packages and wallpaper base. The most commonly used latexes consist of polymers or copolymers of styrene, butadiene, acrylates, vinyl acetate and polyolefins dispersed in water. Several additives are used to reach the desired level of consistency, durability and runnability, e.g. colloidal stabilizers, thickeners, waxes, antifoaming agents, biocides and pesticides. There is a need for biopolymer based barrier-coating compositions which are easy and inexpensive to produce, which have good barrier properties with respect to moisture, gas and grease and which have low brittleness. There is also a need for barrier coating compositions which can easily be separated from the cellulose fibres in recycling and repulping processes. Natural polymers or biopolymers that come from renewable sources show many interesting properties in terms of film forming ability and resistance to oxygen and grease. However, the moisture sensitivity of biopolymers makes them inappropriate as barrier films for food packaging applications. Another disadvantage of barriers based on natural polymers is the brittleness of the coatings, i.e. the sensitivity of barrier properties to mechanical stress applied in converting operations. Cracking of the barrier film causes the barrier properties to be lost. The patent document WO 00/40404 describes coated films with improved barrier properties and relates to coating compositions which use a polymeric binder and a nano-scale particle size additive to provide improved moisture barriers. The area concerned is thermoplastic films and the coating compositions are suited for application to polypropylene and polyethylene films in order to improve the barrier characteristics of said polypropylene and polyethylene films and thereby making them acceptable for food packaging applications. The polymers used are not biopolymers and the intention is not to replace petroleum-based plastic films with more environmentally friendly coatings that provide sufficient barrier protection to paper or paperboard. The patent document EP 1 736 504 describes improvement of barrier properties of a water soluble gas barrier material by adding nanoparticles of calcium carbonate. The polymers used are synthetic polymers and not biopolymers and the purpose is to improve oxygen barrier properties, not water vapour barrier properties. The patent document WO 03/078734 describes a composition for surface treatment of paper by use of nanoparticles of synthetic layered silicates or precipitated calcium carbonate in a carrier fraction comprising plate-like pigment particles (talc and/or kaolin) and a binder such as a polymer latex (styrene-butadiene). The purpose is to improve the printing properties of paper, not to provide paper with improved barrier properties. Starch is mentioned as a surface sizing agent in order to improve the strength of the paper surface. A study by Thang, X, Alavi, S and Herald, T, (Carbohydrate Polymers 74 (2008) 552-558 [available online 22 Apr. 2008]) considers corn starch with glycerol (0-20 wt %), urea (15 wt %) or formamide (15 wt %) as plasticizer. Montmorillonite clay is added to 6 wt %. Both the plasticizer and especially the clay concentrations are lower than in our ‘most preferred’ formulation. Furthermore, the materials were mixed by a twin-screw extruder, followed by grinding and dispersion of the ground material in water. Finally, the water dispersion was cast to self-supporting films. The WVTR was measured at 25° C. and 75% RH. A study by Kampeerapappum, P, Aht-ong, D, Pentrakoon, D and Srikulkit, K, (Carbohydrate Polymers 67 (2007) 155-163 [available online 23 Jun. 2006]) refers to cassava starch in combination with chitosan (0-15% of the dry amount of starch). Chitosan is used as a compatibilizing agent to get a homogeneous dispersion of montmorillonite clay in the starch matrix. Clay was added at a concentration of 0-15 wt % of the dry amount of starch. Glycerol was used as a plasticizer. Self-supporting films with a thickness of about 70 μm were cast from the aqueous dispersion. WVTR was measured at 38° C. and 90% RH and values of 1000-2000 g/m 2 ·d were reported. These values are 10-20 times higher than for paper coatings, measured under the same conditions (Example 6 below). In a study by Cyras, V P, Manfredi, L B, Ton-That, M-T and Vázquez, A, (Carbohydrate Polymers 73 (2008) 55-63 [available online 22 Nov. 2007]) native starch (not chemically modified) is used in combination with 0-5 wt % Na-Cloisite. Self-supporting films were cast from water solution and the resulting film thickness was 250 μm. The equilibrium water uptake and water absorption rate was measured, but the article do not report any measurement of water vapour barrier properties. SUMMARY OF THE INVENTION It is an object of the present invention to overcome or at least minimize at least one of the drawbacks and disadvantages of the above described prior art. This can be obtained by providing barrier coatings based on natural polymers with improved barrier properties for coating of cellulose based substrates, e.g. paper and paperboard. The barrier coatings of the present invention are easily applied as water-borne dispersions on paper and paperboard, are environmentally safe, have excellent film-forming properties and has competitive barrier properties with respect to oxygen, grease and moisture. The barrier films formed by the applied dispersion show an intermediate brittleness and therefore some resistance to mechanical stress. Starch from potato is an example of a biobased polymer with several interesting features. It is renewable, highly available at low price, approved for food contact and has potential for chemical modification. Starch can be native starch, degraded and/or chemically modified. Chemically modified starch can easily be applied as water-borne dispersions on paper and paperboard and shows excellent film-forming properties. The film formed has in general good resistance to grease and oxygen but is highly moisture sensitive. In the present invention oxidized, hydroxypropylated potato starch was chosen as the biopolymer. Other possible biobased polymer materials could be starch from other plant sources (e.g. wheat or corn); starch with other types of chemical modification, or cellulose derivatives. It has been found that addition of nanoparticles are very helpful in lowering the moisture sensitivity of the barrier film. In nanotechnology, a particle is defined as a small object that behaves as a whole unit in terms of its transport and properties. It is further classified according to size. Nanoparticles have one dimension in the range between 1 and 100 nanometers and may or may not exhibit size-related properties that differ significantly from those observed in fine particles or bulk materials. Although the size of most molecules would fit into the above outline, individual molecules are usually not referred to as nanoparticles. Nanoparticles are, in the present invention, defined as having a size below 100 nm and can be either inorganic (silicates, metal oxides) or organic (polymers, dyes). In the present invention nano-sized clay particles, hereinafter called nanoclay, have been investigated. Clay is a generic term which encompasses a well-documented range of minerals; some pertinent examples of which include the kaolinite group, the talc group, the smectite group (which includes montmorillonite, hectorite, saponite and their associated impurities), the vermiculite group, the illite group, the chlorite group and the mica/brittle mica group. It is important to recognize the important group called bentonites. Bentonites are impure smectites, particularly montmorillonite, which contain ancilliary minerals such as quartz, cristabolite, feldspar, mica, illite, calcium carbonate and titania. Commercial bentonites are the most common source of montmorillonite which is a layered clay mineral with an aluminosilicate structure having a hydrophilic character. Through surface modification, swelling clays can be made organophilic, which makes them more compatible and more easily dispersible in organophilic polymers. The process replaces the naturally occurring Na + -ions in the swelling clay galleries with organic cations, e.g. alkylammonium or alkylphosphonium (onium) surfactants. The nanoclays used in the present invention have ion exchange capacities and belong to the bentonite type of clays, more precisely sodium montmorillonite and calcium montmorillonite and blends thereof. Other possible nanoclays would be multivalent- or organic cation exchanged grades and inorganic cation-exchanged clays, as well as other clays which can be purified and suitably ion exchanged, all of which are available from commercial suppliers and as samples or gifts from deposits from all around the world. The relationship between surface diameter and thickness of the nanoclay particles is defined as the aspect ratio. Typically, commercial nanoclays have aspect ratios between 50 and 1000, which is much larger than for typical clay pigments (10-30) used in conventional paper or paperboard coating. The large aspect ratio of nanoclays makes them effective for barrier improvement even at very low (≦5% by weight) concentrations. Higher weight additions may be difficult from a processing perspective, because the viscosity of the dispersions increases significantly at increased loads of clay. The use of nanoparticles in paper and paperboard coating is thus advantageous, particularly given that less material is required (thinner coating layers) to reach the desired barrier or mechanical properties. Less material use leads to reduced costs and reduced amounts of waste. However, a disadvantage with the addition of nanoclay is that nanoclay exacerbates the brittleness of the film. To overcome the problems with brittleness of starch films and cracking of the barrier film it has been found that addition of plasticizers to the barrier composition increases the film flexibility and maintains the protective properties. The barrier and mechanical properties are however strongly affected by the nature and amount of the plasticizer. It has also been found that the relative proportions between chemically modified starch, nanoclay and plasticizer can be adjusted to meet the requirements set on processability of the formulation for industrial scale application. The plasticizer molecules (often short-chain, low-molecular-weight polymers or oligomers) arrange themselves between the polymer chains such that the intermolecular hydrogen bonding is disrupted, hence giving films with less stiffness. The most commonly used plasticizer for starch and proteins is glycerol. Other hydrophilic plasticizers include sorbitol, polyethylene glycol (PEG) and polypropylene glycol (and mixtures thereof), polyvinyl alcohol (PVOH), amino acids, amides, di- and triethanolamine. Organophilic (hydrophobic) plasticizers, such as diacetin, triacetin and tributyrin, can also be used. The plasticizer can also be a mixture including both hydrophilic and organophilic plasticizers. The plasticizer not only affects the properties of the polymer matrix, it also interacts with the clay particles and thereby influences their orientation in the coating layer. Multilayer coating is more effective than just increasing the coat weight. The coverage of the substrate surface is increased by multilayer coating. Calendering of the paper or paperboard improves the barrier properties by elimination of coating defects. The biopolymer barrier coating dispersion can be applied on uncoated surfaces as well as on pre-coated surfaces which consist of a pigment coating, a biopolymer based coating, a dispersion barrier coating or laminates thereof. The ordering of clay platelets in the coating is affected by plasticizer type, application strategy and post-treatment and will affect the final barrier properties. BRIEF DESCRIPTION OF THE DRAWINGS The invention will in the following be described more detailed with reference to the appended drawings, in which: FIG. 1 shows XRD patterns for the coated samples presented in Table 3a. The sample designation G refer to glycerol and PEG to polyethylene glycol. The values within brackets are the concentration of plasticizer in pph. FIG. 2 shows various sequences of mixing the three components of the biopolymer based coating composition of the present invention. FIG. 3 shows flow curves for OHP starch-plasticizer-Na/Ca-Cloisite formulations at 60° C. and where the figure legends refer to the Na/Ca-Cloisite ratio. DETAILED DESCRIPTION The following description is of the best mode for practicing the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be ascertained with reference to the issued claims. The present invention describes the performance of water-based coating formulations of oxidized, hydroxypropylated starch, henceforth called OHP starch, plasticized with glycerol or polyethylene glycol or sorbitol or triacetin to which different loads of sodium montmorillonite and/or calcium montmorillonite has been added. The plasticizer was added to reduce the brittleness of the coating. The goal is to get an aqueous coating suspension which has an appropriate viscosity for use in conventional coating applicators. Applying the water-based composition on the paper or paperboard surface comprises the steps of preparing an aqueous based dispersion comprising a biopolymer, a plasticizer and a nanoclay; coating the cellulose based substrate with the dispersion and allowing the dispersion to dry on the substrate. The sodium montmorillonite and calcium montmorillonite used in the present invention have the trade names Na-Cloisite and Ca-Cloisite, respectively, and will be the terms henceforth used. EXAMPLE 1 Effects of Chemicals on Formulation Viscosity Na-Cloisite was dispersed in deionized water in a dispergator using a Cowles propeller operated at a speed of 1000 rpm. Two different concentrations of clay were used: 1) low concentration to get a completely delaminated clay, 2) higher concentration to get as high solids content as possible in the formulations. The viscosity was measured by a Brookfield viscometer operated at 100 rpm (Table 1). TABLE 1 Dispersion of Na-Cloisite in water. Na-Cloisite Solids, % Viscosity, mPas Dispersion 1 4.7 64 Dispersion 2 9.5 4710 Due to the formation of a thick paste at high loads of clay, 9.5% by weight indicates the upper concentration limit of a Na-exchanged clay but not necessarily the upper concentration limit of other clay with other cations (both inorganic and organic) on the exchange sites. OHP starch was cooked to 20% concentration. Glycerol was used as plasticizer and was added to the cooked starch at a constant level of 30 parts per 100 parts of OHP starch on dry basis. Na-Cloisite dispersion 1 or 2 was added at various amounts and the suspensions were mixed by a propeller rotor operated at 500 rpm for 20 minutes. The relative proportions between OHP starch, plasticizer and nanoclay were adjusted to reach a viscosity within the range of 500-2000 mPas, which may be an appropriate viscosity for coating runnability with various coating techniques, while keeping the overall solids content at the highest possible level (Table 2). TABLE 2 Relative proportions of Na-Cloisite-OHP starch-plasticizer and effects on formulation viscosity. Content, % of dry matter Total Viscosity, Na-Cloisite OHP starch Glycerol solids, % mPas 25.2 58.0 16.8 20.4 6510 23.0 51.1 25.9 19.8 2900 15.4 65.1 19.5 14.6 2230 27.3 55.9 16.8 11.7 1200 37.5 39.3 23.2 10.5 850 23.0 48.5 28.6 8.6 240 As can be seen from Table 2, row 4 shows the best result resulting in a viscosity within the viscosity range of 500-2000 mPas. The amount of total solids decreases with increasing addition of dispersion of Na-Cloisite as a result of the addition of more water to the composition. A water dispersion of Na-Cloisite with 9.5 wt % clay was used in the first five experiments and the results are shown in rows 1-5, Table 2. A water dispersion of Na-Cloisite with a lower content of clay (4.7 wt % clay) was used in the experiment which results are shown in row 6, Table 2. Since the content of clay in the water dispersion of Na-Cloisite was low the dispersion contained more water than the dispersions used in the first five experiments. The low content of clay led to a low content of total solids causing a very low viscosity (240 mPas). In both the experiments with results shown in rows 2 and 6, the content of Na-Cloisite was 23.0 wt % of dry matter. Despite of this the viscosities varied much due to the difference in total solids. Further, Table 2 shows that even small variations in total solids results in large variations in viscosity, e.g. a comparison of the results in rows 1 and 2 shows a difference in total solids of 0.6% resulting in a difference in viscosity of 3610 mPas. It is understood from Table 2 that the proportions of the Na-Cloisite-OHP starch-plasticizer and the amount of total solids have a very big influence on the viscosity. It is of great importance to find out the optimal proportions in order to get a viscosity within the range of optimal viscosity for coating runnability. EXAMPLE 2 Effect of Plasticizer Type and Concentration Glycerol and polyethylene glycol (PEG) were used as plasticizers and were added at levels of 10, 20 and 30 parts per 100 parts of OHP starch on dry basis. A water dispersion of Na-Cloisite (with 9.5 wt % clay) was used. The nanoclay dispersion was mixed into the starch-plasticizer solutions while keeping the temperature at 60° C. using a hotplate. Table 3a shows the total solids content, the relative concentrations of Na-Cloisite, OHP starch and plasticizer (as percentages of dry matter) and the resulting Brookfield viscosities (confer Table 2). TABLE 3a Viscosity and water vapour transmission rate (WVTR) for formulations of OHP starch-Na-Cloisite as a function of plasticizer type and concentration. Plasticizer, Total Content, % of dry matter Viscosity, WVTR, d001 d001 pph solids, % Na-Cloisite OHP starch Glycerol PEG mPas g/m 2 · d Å Å 0 20.0 0 100 0 0 1150 295 ± 5  n/a n/a 10 18.5 29.7 63.9 6.4 — 1790 110 ± 6  27.6 21.0 20 19.6 28.3 59.7 12.0 — 1710 91 ± 4 27.6 20.0 30 20.4 25.2 58.0 16.8 — 1800 83 ± 8 21.0 12.6 10 17.8 29.6 63.9 — 6.5 1710 74 ± 6 13.8 — 20 19.4 28.3 59.7 — 12.0 1670 27 ± 1 15.5 — 30 21.2 27.1 56.0 — 16.9 1750 39 ± 2 15.5 — Brookfield viscosities at 100 rpm were recorded at a temperature of 60° C. Data for pure OHP starch is shown for comparison. A viscosity minimum was found at the intermediate plasticizer level (20 pph) and the viscosity values obtained are below target maximum level of 2000 mPas. Slightly lower viscosities were obtained with polyethylene glycol than with glycerol at all plasticizer levels. Based on these data, a OHP starch-plasticizer-nanoclay composition should preferably consist of 20-40 wt % nanoclay, 50-70 wt % OHP starch and 5-30 wt % plasticizer. When using other nanoclays with other cations the of content of nanoclay in the coating composition may be as high as 70 wt %. Laboratory Coating All formulations were coated on a packaging board using a laboratory bench coater fitted with a wire-wound rod. All coated substrates were dried in 105° C. for 2 minutes. Water Vapour Transmission Rate, WVTR The water vapour transmission rate, WVTR, is defined as the amount of water vapour that is transmitted through a unit area in a unit time under specified conditions of temperature and humidity. Common standards for measurement of WVTR by the gravimetric method are ASTM E 96, DIN 53122-1, ISO 2528, TAPPI T 448 and T 464. The WVTR of coated paperboard materials generally decreases exponentially with increased coating layer or film thickness. Permeation will mainly take place through coating defects such as cracks, voids and pinholes or through the amorphous regions of polymer films. Packaging of foodstuff with intermediate requirements on moisture protection typically have a critical level of WVTR below 10 g/m 2 ·d. Materials having WVTR below 1 g/m 2 ·d are considered as good moisture barrier whereas materials having WVTR above 50 g/m 2 ·d are commonly regarded as poor barriers. Measurements of WVTR were carried out with the gravimetric cup method in an environment of 23° C. and 50% RH using silica gel as desiccant and the coated sides exposed to the humid air. WVTR data is presented in Table 3a. All formulations containing Na-Cloisite showed a significant decrease in WVTR compared to the reference OHP starch coating. At all plasticizer levels, the formulations containing polyethylene glycol showed lower WVTR values than those containing glycerol. This may partly be due to the hygroscopic character of the latter. A minimum in WVTR was observed at 20 pph PEG. The effect of a hydrophobic plasticizer (triacetin) and a potentially less hygroscopic, hydrophilic plasticizer (sorbitol) on the WVTR values were also evaluated. Coating and measurement of WVTR was carried out as above. The coating compositions and corresponding WVTR values are shown in Table 3b. TABLE 3b Water vapour transmission rate (WVTR) for formulations of OHP starch- Na-Cloisite as a function of plasticizer type and concentration. Plasti- Content, % of dry matter cizer, Total Na- OHP WVTR, pph solids, % Cloisite starch Sorbitol Triacetin g/m 2 · d 10 17.8 29.6 63.9 6.5 — 61 ± 5 20 19.4 28.3 59.7 12.0 — 40 ± 4 30 21.2 27.1 56.0 16.9 — 25 ± 5 10 17.8 29.6 63.9 — 6.5 54 ± 1 20 19.4 28.3 59.7 — 12.0 49 ± 5 30 21.2 27.1 56.0 — 16.9 38 ± 7 Both these plasticizers were more effective in reducing the WVTR, as compared to glycerol, when used in combination with OHP starch and Na-Cloisite (confer Table 3a). A higher concentration of sorbitol (30 pph) was required to reach the same level of WVTR as was obtained with 20 pph of polyethylene glycol. X-Ray Diffraction Pattern of Coated Paper The barrier properties of nanoclay reinforced coatings are strongly affected by the ordering of the clay particles within the polymer matrix. The gallery spacings between clay particles as an effect of plasticizer type and concentration was therefore analyzed by studying the X-ray Diffraction patterns (XRD) for coated paperboard samples. FIG. 1 presents the x-ray traces for the six samples in Table 3a. These samples all displayed relatively sharp, intense x-ray peaks when using the peak intensities from the paper, at 2Θ values near 16 and 22.5°, as a comparative standard (2Θ refers to the angle between the incident and diffracted x-ray beam). Note that some of the peaks near 5 °2Θ exhibited two poorly resolved peaks. The position of these peaks was used to calculate the d-spacings presented in the two right hand columns in Table 3a. The XRD traces in FIG. 1 illustrate the considerable differences in clay particle ordering and gallery spacing in the presence of PEG compared with glycerol. The broad, weak peaks displayed by the coatings prepared using glycerol suggest that the platelets are poorly ordered with respect to each other, whereas the narrow, intense peaks displayed by the samples containing PEG indicate that the clay platelets are well-aligned with respect to each other and oriented with their basal surface parallel to the paper surface. The d-spacings of the clay in different coatings are shown in the last two columns in Table 3a. The last three samples prepared using PEG, exhibited sharp, intense peaks with d-spacings of 13.8, 15.5 and 15.5 Å, respectively, whereas the samples prepared using glycerol exhibited broader peaks to lower angle indicating more than one gallery spacing. Thus the combination of the WVTR and XRD results indicate that the particular combination of OHP starch-nanoclay-plasticizer used resulted in a very uniform coating which formed on the surface of the paper web. For this reason when the amount of plasticizer exceeds a lower limit (i.e. above 10 pph) the clay becomes uniformly expanded and very well aligned. These aligned stacks of clay particles may help counteract the influence of the deepest depressions in the underlying paper web, encouraging the coating to ‘hold out’ from absorption into the paper web. These aligned clay stacks also appear to increase the tortuosity of the path through the coated paper, thus contributing to an improved barrier to moisture and other gases. EXAMPLE 3 Effect of Mixing Sequence of the Components Various sequences of mixing the three components were investigated and are explicitly illustrated in FIG. 2 . The mixing sequences are presented as non-limiting examples of the practical use of the invention. Sequence 1 is described in Example 1-2 and the proportions between the three components are shown in Table 3a. In Sequence 1 the OHP starch is dispersed in water and cooked, thus forming a biopolymer solution with a starch concentration of 10-30 percent by weight on dry basis. The plasticizer is then added to said biopolymer solution forming a biopolymer-plasticizer solution with a concentration of 10-30 parts plasticizer per 100 parts of biopolymer on dry basis. Finally, a water dispersion of nanoclay is added to the biopolymer-plasticizer solution. Sequence 2 involves the dispersion of nanoclay as a dry substance (and not as a water dispersion of nanoclay as in Seq. 1), henceforth called dry nanoclay, in the OHP starch-plasticizer solution. Sequence 3 implies dispersion of dry nanoclay in a water solution containing a pre-determined amount of plasticizer, followed by mixing the nanoclay-plasticizer-water dispersion with cooked starch to reach identical proportions of the three components as in Example 2 corresponding to 20 parts plasticizer per 100 parts of OHP starch (Table 3a, row 6). This composition was selected for investigation of mixing sequences because it showed the lowest WVTR when following Sequence 1. Sequence 4 implies blending dry nanoclay with OHP starch in powder form, followed by addition of water and plasticizer, prior to cooking, to reach identical proportions of the three components as in Example 2 corresponding to 20 parts plasticizer per 100 parts of OHP starch (Table 3a, row 6). Coating of paperboard and measurement of WVTR was carried out as in Example 2. Table 4 presents results on viscosity and WVTR following the specified mixing sequences (using polyethylene glycol as plasticizer). Sequence 1 is thus preferred from a viscosity perspective. Sequence 4 gives WVTR values of coated paperboard comparable to Sequence 1. In Sequence 3 (and 4) the complete delamination of clay platelets could be obstructed by the presence of plasticizer (or starch) in the water mixture. Furthermore, the presence of nanoclay particles is suspected to impair the swelling and gelatinization of OHP starch granules during the initial cooking step according to Sequence 4. Sequence 2 resulted in a high increase in the viscosity (>6000 mPas) even at low (14 weight percent on dry basis) additions of nanoclay and hence the composition fell outside the range for making application on paper possible. The advantage with this mixing procedure is however that the total solids content of the OHP starch-plasticizer-nanoclay formulation can be raised to higher levels than with any of the other methods. TABLE 4 Brookfield viscosity of OHP starch-plasticizer-nanoclay formulations as an effect of mixing sequence. WVTR data obtained from coated paperboard. Mixing Sequence Solids, % Viscosity, mPas WVTR, g/m 2 · d 1 15.4 1040 56 ± 2 3 17.9 1320 72 ± 1 4 16.1 1624 47 ± 5 With respect to practical utilize, appropriate viscosity range and acceptable WVTR, and lack of those problems associated with the other sequences specified above, Sequence 1 was selected as the most successful one. An alternative mixing procedure would be to disperse nano-sized clay in water forming a water dispersion of nano-sized clay at a concentration of 5-10 percent by weight on dry basis and to dissolve the biopolymer in water forming a biopolymer solution at a concentration of 10-30 percent by weight on dry basis and then to add the biopolymer solution to the water dispersion of nano-sized clay followed by addition of the plasticizer. Another alternative mixing procedure would be to disperse nano-sized clay at a concentration of 5-10 percent by weight on dry basis, the plasticizer is added to said water dispersion forming a water dispersion of nano sized clay-plasticizer, dissolve the biopolymer in water forming a water solution of biopolymer at a concentration of 10-30 percent by weight on dry basis followed by mixing the water solution of biopolymer with the nano sized clay-plasticizer dispersion. The different mixing sequences result in the same final composition of the biopolymer based barrier coating composition but the viscosity of the final coating composition may differ from mixing sequence to mixing sequence as a result of in which order the components have been added. As already mentioned, mixing Sequence 1 is preferred from a viscosity perspective for mixing the components in the desired proportion. If another mixing proportion of the ingredients is preferred, one of the other mixing sequences may be more advantageous in order to reach a viscosity within the preferred viscosity range of 500-2000 mPas. EXAMPLE 4 Effect of Gallery Cation on Starch-Plasticizer-Nanoclay Dispersion and Coating Properties Dry blends of Na-Cloisite and Ca-Cloisite with the following Na/Ca percentage ratios were mixed: 100/0; 80/20; 60/40; 50/50; 40/60; 20/80 and 0/100. The Na/Ca-Cloisite blends were dispersed in deionized water in a dispergator. The resulting solids content was about 8% in all dispersions. OHP starch was cooked to 20% concentration. Polyethylene glycol was added to the cooked starch solution corresponding to 20 parts polyethylene glycol per 100 parts starch on dry basis. The Na/Ca-Cloisite dispersions were added to the starch-plasticizer solution as in Example 2. The resulting compositions were 27 wt % clay, 61 wt % OHP starch and 12 wt % PEG on dry basis. Viscosity The viscosity of the OHP starch-plasticizer-nanoclay dispersions were measured by a controlled shear stress rheometer (Physica MCR 300, Physica Messtechnik GmbH, Ostfildern, Germany) with shear rates from 1 to 4000 s −1 in concentric cylinder geometry at 60° C. Flow curves are shown in FIG. 3 . All types of dispersions showed shear thinning behavior. It was anticipated that mixtures of Na- and Ca-exchanged nanoclay would exhibit a reduced viscosity which would allow higher nanoclay contents to be used. The results showed that the overall viscosity of the OHP starch-plasticizer-Na/Ca-Cloisite dispersions decreased with increasing amount of Ca-Cloisite. A remarkably large decrease in the viscosity was observed when going from 60 to 80% Ca-Cloisite and similarly when going from 80 to 100%. Laboratory Coating and WVTR Coating of paperboard and measurement of WVTR were carried out as in Example 2. The dry coating thickness was measured to about 15-20 μm and the coat weights were determined to about 6-8 g/m 2 . The effect of Na/Ca-Cloisite ratio on WVTR is shown in Table 5. TABLE 5 WVTR as an effect of Na/Ca-Cloisite ratio. Na/Ca-Cloisite ratio WVTR, g/m 2 · d 100/0   56 ± 2 80/20  51 ± 1 60/40  68 ± 4 50/50  58 ± 3 40/60  69 ± 1 20/80 114 ± 5  0/100 220 ± 3 In general, the WVTR was found to increase with increasing content of Ca-Cloisite. At 100% Ca-Cloisite, there is only a slight improvement of the barrier compared to the pure OHP starch coating (ca 295 g/m 2 ·d). The data suggest however, that introduction of a small amount of Ca-Cloisite (maximum 20%) may favor the water vapor barrier properties over a coating with pure Na-Cloisite. EXAMPLE 5 Effect of Pre-Coating The effect of Ca-Cloisite was further studied in the region between 0 and 20 wt % to validate the positive effect of a small amount of a divalent cation in the clay gallery, and to find out the optimum mixture of monovalent and divalent cations with respect to barrier properties. The proportions between nanoclay, starch and PEG was kept constant at 27:61:12 on dry basis. The OHP starch-PEG-Na/Ca-Cloisite formulations were applied on paperboard by bench coater in a single layer of about 8-10 g/m 2 as described in previous examples. To study the effect of a pre-coating on the barrier performance, the formulations were applied in a single layer on top of the following substrates: Uncoated paperboard Pigment coated paperboard Paperboard pre-coated with the same OHP starch-PEG-Na/Ca-Cloisite formulation; coat weight about 8-10 g/m 2 Paperboard pre-coated with OHP starch-plasticizer; coat weight 13 g/m 2 Paperboard pre-coated with a double layer of styrene-acrylate (SA) barrier latex; total coat weight 29 g/m 2 Paperboard pre-coated with a double layer of styrene-butadiene (SB) barrier latex filled with talc particles; total coat weight 28 g/m 2 Water Vapor Barrier Properties WVTR values for the pre-coated substrates and the same substrates top-coated with the different Na/Ca-Cloisite formulations are shown in Table 6. The talc-filled barrier latex shows low WVTR values and should represent one of the most efficient dispersion barriers, using non-sustainable polymer matrices, commercially available on the market today. TABLE 6 WVTR as a function of pre-coatings of different Na/Ca-Cloisite formulations. WVTR, g/m 2 · d Na/Ca-Cloisite ratio Substrate pre-coating Substrate 100/0 95/5 90/10 85/15 80/20 Uncoated paperboard 373 ± 4 57 ± 1 50 ± 2 54 ± 1 50 ± 4 56 ± 4 Pigment coated paperboard 341 ± 5 42 ± 1 43 ± 2 43 ± 2 42 ± 2 45 ± 1 OHP-PEG-Na/Ca-Cloisite — 33 ± 5 29 ± 3 30 ± 6 26 ± 3 27 ± 2 OHP-PEG 256 ± 3 127 ± 10 125 ± 13 100 ± 7  93 ± 7 107 ± 5  SA-latex  65 ± 1 33 ± 1 36 ± 5 33 ± 3 31 ± 1 32 ± 2 SB-latex (talc filled)  17 ± 3 11 ± 2 13 ± 3 11 ± 3 13 ± 3 13 ± 3 A single layer (ca 8-10 g/m 2 ) of OHP starch-PEG-Na/Ca-Cloisite resulted in a WVTR around 50-57 g/m 2 ·d, irrespective of the Na/Ca-Cloisite ratio (Table 6, row 1). It is notable that these values are lower than for a double layer coating of the SA-latex (WVTR 65 g/m 2 ·d; Table 6, row 5) despite that the coat weight of the SA-latex coating (29 g/m 2 ) was three times higher. Application of the OHP starch-PEG-Na/Ca-Cloisite formulations on top of a conventional pigment pre-coating has a favorable effect on the WVTR, with a 15-25% reduction. This should be due to a more surface-located barrier layer, i.e. reduced porosity of the substrate prevents too severe absorption of the barrier coating into the fiber structure. Application of the OHP starch-PEG-Na/Ca-Cloisite formulations in two separate layers (total thickness measured to be about 30-40 μm and total coat weight determined to be about 16-20 g/m 2 ) led to a reduction of WVTR by about 50% (Table 6, row 3). Also in this case it was found that an introduction of a small amount of Ca-Cloisite may favor the water vapor barrier properties over a coating with pure Na-Cloisite. Application of the OHP starch-PEG-Na/Ca-Cloisite formulations on top of an OHP starch-PEG or a SA-latex pre-coating led to a reduction of WVTR by 50% as compared to the barrier level provided by these pre-coatings themselves. A slight trend towards lower WVTR values in the presence of 10 to 20% Ca-Cloisite was observed. Addition of a small amount of divalent gallery cations to the monovalent Na + -ions thus improves the barrier properties. The WVTR of the talc-filled styrene-butadiene latex coated paperboard was further reduced by application of the OHP starch-PEG-Na/Ca-Cloisite on top and these combined pre- and top coatings together give WVTR values approaching the target level of ≦10 g/m 2 ·d set for food packaging with intermediate demand for water vapor barriers. The combination of two layers of OHP starch-PEG-Na/Ca-Cloisite (Table 6, row 3) and one layer of OHP starch-PEG-Na/Ca-Cloisite on top of a SA-latex pre-coating (Table 6, row 5) also results in acceptable WVTR values, around 30 g/m 2 ·d. Application in two layers will, besides an increased coat weight, also promote good barrier properties by eliminating the effect of pinholes and coating defects since these will most likely not propagate through both layers. Another likely positive effect is that the presence of well-ordered clay platelets throughout the coating will increase the probability of a substantially extended pathway for diffusing water vapor, and other, molecules at all locations of ingress over the surface. Another alternative coating approach may be to first apply a single or double layer of biopolymer based barrier coating followed by application of a layer of a barrier latex coating, i.e. a first, single or double, layer of OHP starch-PEG-Na/Ca-Cloisite is applied to the paper or paperboard followed by application of a top coating comprising a dispersion barrier latex. The applications and coatings described above have been applied on one side of the paperboard but can of course be applied in the same way on the opposite side of a paper or paperboard resulting in paper and paperboard coated on both sides. EXAMPLE 6 Effect of Temperature, Moisture and Mechanical Forces The water vapor transmission rate of the most promising coatings, i.e. the OHP starch-plasticizer-nanoclay formulations applied in two layers (row 3 in Table 6) and the OHP starch-plasticizer-nanoclay formulations applied on top of the talc-filled SB-latex (row 6 in Table 6) was also measured at elevated relative humidity (23° C. and 85% RH) and at tropical conditions (38° C. and 90% RH). Both testing conditions are standard climates according to DIN 53122 and ISO 2528. In the packaging industry, the test conditions are often set to 23° C. and 85% RH to match realistic packaging environments. The tests were carried out in a climate chamber. All samples were conditioned for >12 hours in each climate before starting the test. The results are shown in Table 7 for OHP starch-plasticizer-nanoclay formulations with various Na/Ca-Cloisite ratios applied in two layers (2 nd column) and on top of the talc filled SB-latex pre-coating (3 rd and 4 th columns) at specified testing climates. Also given are reference data for the commercial barrier latex. TABLE 7 Effects of temperature and relative humidity on WVTR for various OHP starch-plasticizer-nanoclay compositions. WVTR, g/m 2 · d SB-latex (talc filled) Na/Ca-Cloisite ratio 23° C. 85% RH 23° C. 85% RH 38° C. 90% RH 100/0  340 ± 47 40 ± 5 139 ± 2  95/5  133 ± 0  31 ± 7 106 ± 0  90/10 300 ± 1  35 ± 3 139 ± 0  85/15 367 ± 27 46 ± 9 169 ± 21 80/20 265 ± 0  37 ± 0 139 ± 42 SB-latex (talc filled) 80 ± 5 217 ± 42 Increased temperature and humidity also increased the scatter in the data, which should be due to exaggerated impact of pinholes and coating defects (Table 7). The OHP starch/plasticizer/nanoclay coating is highly sensitive to enhanced moisture, due to the hygroscopic character of starch. Also the talc-filled SB-latex reacts strongly to increased moisture, with a 4-5 times increase in WVTR when going from 50% to 85% RH. However, the combination of a nanoclay top coating on a talc filled SB-latex pre-coating acts to keep the WVTR on a reasonable level at standard packaging testing conditions of 23° C. and 85% RH (Table 7). The tougher testing conditions however did facilitate the differentiation of inherent coating properties and a trend for lower WVTR for the coating containing 95/5 Na/Ca-Cloisite is clearly seen in all three columns in Table 7. Effect of Creasing Creasing tests were carried out in order to study the brittleness of the coatings, i.e. the sensitivity of barrier properties to mechanical stress applied in converting operations. A simplified creasing assembly based on the design given in the TAPPI method UM 590 “Creasing of paperboard for water vapor transmission rate (WVTR) testing” was produced. The coated paperboard samples were creased once in the machine direction by placing the coated side down on the creasing rule and then applying the upper plate on top of it. A steel roller with a weight of 10.0 kg was rolled once forwards and once backwards along the length of the plate. After removal, the creased sample was folded 180° by hand towards the coated side. The steel roll was rolled over the folded sample once again, followed by flattening of the samples and repeated testing of the water vapour barrier properties (Table 8). The results should be compared to the uncreased samples in Table 6 (third row). Also given is reference data for the commercial barrier latex. TABLE 8 Effect of creasing on WVTR for various OHP starch- plasticizer-nanoclay formulations. Na/Ca-Cloisite ratio WVTR, g/m 2 · d 100/0  72 ± 9 95/5  59 ± 5 90/10 69 ± 5 85/15 70 ± 2 80/20 65 ± 3 SB-latex (talc filled) 30 ± 6 Creasing leads to a significant loss of barrier properties for both the OHP starch/plasticizer/nanoclay and the reference SB-latex barrier coatings. The data indicates however once again that the barrier properties are improved by a small addition of Ca-Cloisite, with a minimum in WVTR for the formulation with 95/5 Na/Ca-Cloisite. It is evident that enhanced moisture (Table 7) has a greater negative effect on the WVTR than has induced mechanical stress. COMPARATIVE EXAMPLE 1 For comparison, a commercial nanocomposite coating consisting of a nanosilicate dispersed in a polyester resin (Nanolok PT 3575, InMat Inc.) was applied on top of the talc-filled SB-latex. The obtained WVTR was 9±1 g/m 2 ·d. As evident from Table 6, some of the starch-based nanoclay coatings are tangent to these values. Summary and Conclusions Double layer application seem to be more efficient for reduction of WVTR than the application of an increased thickness of an applied single layer. Starch-based nanoclay coatings were proven to offer competitive WVTR values when compared with commercial unfilled styrene-acrylate dispersion coatings. Starch-based nanoclay top coatings were shown to give the same level of water vapor barrier as commercial nanocomposite top coatings when applied on a suitable pre-coated paperboard. These combined pre- and top coatings together give WVTR values approaching the target level of ≦10 g/m 2 ·d set for food packaging with intermediate demand for water vapor barriers. The surface energy of the pre-coating and the surface tension of the top coating is beneficially controlled to get optimum wetting and spreading properties of the top coating layer. A conventional, inexpensive pigment pre-coating strongly facilitates the barrier properties of a starch-based nanoclay coating. A small addition of Ca-Cloisite (5-10% by weight) has a positive effect on the WVTR of starch/plasticizer/nanoclay coatings. The effect is exaggerated at testing conditions involving enhanced temperature, enhanced moisture and induced mechanical stress (creasing). A higher load of nanoclay than conventional may be used. The successful formulation of the aqueous coating composition resulted in remarkably low WVTR values when applied on paper or paperboard. Very low WVTR values are achieved when applying the starch/clay nanocomposite on a barrier latex pre-coating. Positive synergistic effects of the plasticizer polyethylene glycol (PEG) and the controlled balance of counter ions (mixture of Na- and Ca-Cloisites) are observed. The nanoclay acts as a compatibiliser between starch and PEG. It is understood that the objects of the present invention set forth above, among those made apparent by the detailed description, shall be interpreted as illustrative and not in a limiting sense. The skilled person in the art realizes that other clays, e.g. hectorite, saponite, nontronite, vermiculite and their synthetic counterparts, may offer the same enhancement of barrier properties and still fulfill the basic principles according to this invention. The same person also realizes that different types of coating machineries to coat the cellulose based substrate, e.g. paper or paperboard, may be used, e.g. blade, roll or curtain coating machines and still fulfill the basic principles according to the present invention.

The present invention relates to a biopolymer based barrier coating composition wherein said biopolymer based barrier coating composition comprises a plasticizer, a nano-sized clay and a biopolymer comprising a native starch and/or a de-graded starch and/or a chemically modified starch. The present invention also relates to a method for preparing the biopolymer based barrier coating composition as well as to a method for coating a cellulose based substrate with the biopolymer based barrier coating composition. Finally, the present invention relates to a cellulose based substrate coated with said biopolymer based barrier coating composition.

CLAIM TO PRIORITY [0001] The present invention claims priority to U.S. Provisional Application No. 60/551,262, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR IMPROVED DRILLING AND MILLING TOOLS FOR RESECTION,” and U.S. Provisional Application No. 60/551,080, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR PIVOTABLE GUIDE SURFACES FOR ARTHROPLASTY,” and U.S. Provisional Application No. 60/551,078, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR MINIMALLY INVASIVE RESECTION,” and U.S. Provisional Application No. 60/551,096, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR ENHANCED RETENTION OF PROSTHETIC IMPLANTS,” and U.S. Provisional Application No. 60/551,631, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR CONFORMABLE PROSTHETIC IMPLANTS,” and U.S. Provisional Application No. 60/551,307, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR IMPROVED CUTTING TOOLS FOR RESECTION,” and U.S. Provisional Application No. 60/551,160, filed Mar. 8, 2004, entitled, “METHODS AND APPARATUS FOR IMPROVED PROFILE BASED RESECTION,” and U.S. patent application Ser. No. 11/036,584, filed Jan. 14, 2005, entitled, “METHODS AND APPARATUS FOR PINPLASTY BONE RESECTION,” and U.S. patent application Ser. No. 11/049,634, filed Feb. 3, 2005, entitled, “METHODS AND APPARATUS FOR WIREPLASTY BONE RESECTION,” which claims priority to U.S. Provisional Application No. 60/536,320, filed Jan. 14, 2004, and U.S. patent application Ser. No. 11/049,634, filed Feb. 3, 2005, entitled, “METHODS AND APPARATUS FOR WIREPLASTY BONE RESECTION,” which claims priority to U.S. Provisional Application No. 60/540,992, filed Feb. 2, 2004, entitled, “METHODS AND APPARATUS FOR WIREPLASTY BONE RESECTION,” the entire disclosures of which are hereby fully incorporated by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention generally relates to methods and apparatus for bone resection to allow for the interconnection or attachment of various prosthetic devices with respect to the patient. More particularly, the present invention relates to methods and apparatus for improved drilling and milling tools for resection and arthroplasty. [0004] 2. Background Art [0005] Different methods and apparatus have been developed in the past to enable a surgeon to remove bony material to create specifically shaped surfaces in or on a bone for various reasons including to allow for attachment of various devices or objects to the bone. Keeping in mind that the ultimate goal of any surgical procedure is to restore the body to normal function, it is critical that the quality and orientation of the cut, as well as the quality of fixation, and the location and orientation of objects or devices attached to the bone, is sufficient to ensure proper healing of the body, as well as appropriate mechanical function of the musculoskeletal structure. [0006] In total knee replacements, for example, a series of planar and/or curvilinear surfaces, or “resections,” are created to allow for the attachment of prosthetic or other devices to the femur, tibia and/or patella. In the case of the femur, it is common to use the central axis of the femur, the posterior and distal femoral condyles, and/or the anterior distal femoral cortex as guides to determine the location and orientation of distal femoral resections. The location and orientation of these resections are critical in that they dictate the final location and orientation of the distal femoral implant. It is commonly thought that the location and orientation of the distal femoral implant are critical factors in the success or failure of the artificial knee joint. Additionally, with any surgical procedure, time is critical, and methods and apparatus that can save operating room time, are valuable. Past efforts have not been successful in consistently and/or properly locating and orienting distal femoral resections in a quick and efficient manner. [0007] The use of oscillating sawblade based resection systems has been the standard in total knee replacement and other forms of bone resection for over 30 years. Unfortunately, present approaches to using existing planar or non-planar saw blade instrumentation systems all possess certain limitations and liabilities. [0008] Perhaps the most critical factor in the clinical success of any bone resection for the purpose of creating an implant surface on the bone is the accuracy of the implant's placement. This can be described by the degrees of freedom associated with each implant. In the case of a total knee arthroplasty (TKA), for example, for the femoral component these include location and orientation that may be described as Varus-Valgus Alignment, Rotational Alignment, Flexion-Extension Alignment, A-P location, Distal Resection Depth Location, and Mediolateral Location. Conventional instrumentation very often relies on the placement of ⅛ or 3/16 inch diameter pin or drill placement in the anterior or distal faces of the femur for placement of cutting guides. In the case of posterior referencing systems for TKA, the distal resection cutting guide is positioned by drilling two long drill bits into the anterior cortex across the longitudinal axis of the bone. As these long drills contact the oblique surface of the femur they very often deflect, following the path of least resistance into the bone. As the alignment guides are disconnected from these cutting guides, the drill pins will “spring” to whatever position was dictated by their deflected course thus changing their designated, desired alignment to something less predictable and/or desirable. This kind of error is further compounded by the “tolerance stacking” inherent in the use of multiple alignment guides and cutting guides. [0009] Another error inherent in these systems further adding to mal-alignment is deflection of the oscillating sawblade during the cutting process. The use of an oscillating sawblade is very skill intensive as the blade will also follow the path of least resistance through the bone and deflect in a manner creating variations in the cut surfaces which further contribute to prosthesis mal-alignment as well as poor fit between the prosthesis and the resection surfaces. Despite the fact that the oscillating saw has been used in TKA and other bone resection procedures for more than 30 years, there are still reports of incidences where poor cuts result in significant gaps in the fit between the implant and the bone. Improvements in the alignment and operation of cutting tools for resecting bone surfaces are desired in order to increase the consistency and repeatability of bone resection procedures as is the improvement of prosthetic stability in attachment to bone. [0010] One technique that has been developed to address these challenges has been the profile based resection (PBR) techniques taught, for example, by U.S. Pat. Nos. 5,514,139, 5,597,397, 5,643,272, and 5,810,827. In a preferred embodiment of the PBR technique, a side cutting tool such as a milling bit or side drill bit is used to create the desired resected surface. While the PBR technique offers many advantages over conventional resection and arthroplasty techniques, it would be desirable to provide enhancements to the PBR technique that improve the ability to address soft tissue management SUMMARY OF THE INVENTION [0011] The present invention provides for embodiments of milling and drilling tools and soft tissue management techniques for arthroplasty facilitating intraoperative and postoperative efficacy and ease of use. In one embodiment, resiliently biased soft tissue protective sleeves surround the side cutting tool and are interposed along the longitudinal axis of the side cutting tool adjacent each side of the bone. The soft tissue protective sleeves are biased to track along the contour of the side of the bone and prevent the side cutting tool from being exposed to soft tissue during the resection. In another embodiment, a pilot drill is initially utilized to create an initial bore in the bone to be resected. The pilot drill preferably has an end cutting arrangement and a non-cutting removal channel that minimizes the tendency of the pilot drill bit to drift off-axis as the initial bore in the bone is created. Once the initial bore is created, the pilot drill bit is withdrawn and a second side cutting tool, such as a milling bit, is then inserted into the bore to perform the desired surface resection. [0012] The present invention utilizes a number of embodiments of cutting tools to remove boney material to create cut surfaces for prosthetic implant attachment and fixation. The overriding objects of the embodiments are to provide the ability to perform resection in very small incisions, the creation of precise and accurate cut(s), and to provide for soft tissue protection characteristics and features preventing the tool from accidentally harming soft tissue. Specifically, many of the cutting tool embodiments disclosed are either incapable or highly resistant to damaging soft tissue, or are by means disclosed prevented from coming into contact with soft tissue in the first place. [0013] The present invention utilizes a number of embodiments of cutting guide technologies loosely or directly based on Profile Based Resection (PBR). The overriding objects of PBR technologies are to provide for significantly improved reproducibility of implant fit and alignment in a manner largely independent of the individual surgeon's manual skills, while providing for outstanding ease of use, economic, safety, and work flow performance. [0014] The present invention utilizes a number of embodiments of alignment or drill guides to precisely and accurately determine the desired cutting guide location/orientation, thus cut surface location(s)/orientation(s), thus prosthetic implant location and orientation. The overriding objects of the embodiments are to precisely and accurately dictate the aforementioned locations and orientations while optionally enabling ease of use in conjunction with manually or Computer Assisted techniques, and while optionally enabling ease of use in minimally invasive procedures where surgical exposure and trauma are minimized. [0015] The present invention utilizes a number of methods and apparatus embodiments of soft tissue management techniques and the devices supporting said techniques. The overriding object of these embodiments is to take advantage of the anatomy, physiology, and kinematics of the human body in facilitating clinical efficacy of orthopedic procedures. [0016] It is an often repeated rule of thumb for orthopedic surgeons that a “Well placed, but poorly designed implant will perform well clinically, while a poorly placed, well designed implant will perform poorly clinically.” The present invention provides a method and apparatus for reducing implant placement errors in order to create more reproducible, consistently excellent clinical results in a manner that decreases risk to soft tissue, incision or exposure size requirements, manual skill requirements, and/or visualization of cutting action. [0017] It should be clear that applications of the present invention is not limited to Total Knee Arthroplasty or the other specific applications cited herein, but are rather universally applicable to any form of surgical intervention where the resection of bone is required. These possible applications include, but are not limited to Unicondylar Knee Replacement, Hip Arthroplasty, Ankle Arthroplasty, Spinal Fusion, Osteotomy Procedures (such as High Tibial Osteotomy), ACL or PCL reconstruction, and many others. In essence, any application where an expense, accuracy, precision, soft tissue protection or preservation, minimal incision size or exposure are required or desired for a bone resection and/or prosthetic implantation is a potential application for this technology. In addition, many of the embodiments shown have unique applicability to minimally invasive surgical (MIS) procedures and/or for use in conjunction with Surgical Navigation, Image Guided Surgery, or Computer Aided Surgery systems. BRIEF DESCRIPTION OF THE DRAWINGS [0018] Other important objects and features of the invention will be apparent from the following detailed description of the invention taken in connection with the accompanying drawings in which: [0019] FIGS. 1, 2 , and 3 are pictorial representations standard incision sizes or exposure required by the prior art, while [0020] FIG. 4 is a pictorial representation or approximation of one form of surgical exposure that is desired. [0021] FIGS. 5-98 , 111 , 119 , and 125 - 127 show various depictions of embodiments and methods in accordance with alternate embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0022] It should be noted that, in many of the figures, the cut surface created by the cutting tool in accordance with the techniques of the present invention are shown as having already been completed for the sake of clarity. Similarly, the bones may be shown as being transparent or translucent for the sake of clarity. The guides/pins, cutting tool, bones, and other items disclosed are may be similarly represented for the sake of clarity or brevity [0000] FIGS. 1 through 4 [0023] FIGS. 1 and 2 show conventional surgical exposures and instrumentation being utilized. FIG. 4 shows a reduced incision currently utilized in performing the current state of the art in ‘minimally invasive’ Unicondylar Knee Replacement. [0000] FIGS. 41-60 [0024] FIGS. 41 through 60 represent an embodiment of the present invention the soft tissue protection sleeves and milling/drilling bit management techniques that enable Triple Transcutaneous Transarticular TKA (“TTTKA” or “Triple TKA” or “T Cubed” or “T 3 ” Procedures). The soft tissue protection sleeves shown, for example, in FIGS. 42 and 43 . One clinical application calling for the benefits of this feature would be where a PBR cutting guide, as generally shown in FIG. 35 is positioned completely outside of the wound with the exception of fixation features which extend from the externally located guides through skin incisions and into holes or apertures created in bone. As shown in FIGS. 52 and 53 , the cutting tool, in the case of the present invention a side cutting drill, is extended through the handle, the guide, the skin, fat, capsule, etc (soft tissue), across, across and in front of, through, or beneath the articular surfaces of the joint, and through the soft tissue, guide, and handle on the opposing side of the bone. The soft tissue protection sleeves may be extended through the soft tissue and into contact with the sides of the bone. The retaining lip can be used to maintain the sleeves in contact with the bone and are held there by the edges of the incision through the capsule during cutting. The springs shown in FIG. 43 can further bias the sleeves into contact with bone in a manner that would maintain that contact as the width of the bone changed along the cutting path of the resected surface. [0025] One skilled in the art will note that the thicknesses for the soft tissue through which the sleeves extend change significantly from patient to patient thus requiring the proportions of the sleeve, spring and other components of the present embodiment of the invention to change accordingly. For example, in an obese patient, the fat layer through which the cutting tool extends can be 5 inches thick per side or more. The diameter of the soft tissue protection sleeve can be significantly reduced with respect to what is shown as the side cutting drill diameter is reduced, thus requiring a smaller capsular or other soft tissue incision or ‘stab wound’. [0026] In operation, the handle is manipulated to traverse the cutting path of the cutting guide while the tibia is swung through a range of motion about the femur as shown in comparing FIGS. 54 through 60 . This particular principal of operation takes advantage of the fact that the capsule, the patella, and to a lesser or greater extent the skin, moves with the tibia as it moves through a range of motion with respect to the femur. Thus, a small, perhaps 4 mm to 10 mm long stab wound through skin to the medial side of the posterior femoral condyles (roughly in line with the axis of the pilot drill shown in FIG. 51 ) with the knee bent in flexion, and then looked at the side of the femur (through the portal created by the stab wound) while moving the tibia through a range of motion, the side of the femur would be observed to be passing by/through the portal. In order to complete all of the resected surfaces on the femur necessary to fix a standard femoral prosthesis, it may be necessary in one embodiment to make two passes with the side cutting drill sweeping about the femur with the tibia as represented in FIGS. 54 through 60 . [0027] FIGS. 44 through 51 represent an embodiment of the present invention for use in creating pilot holes allowing for introduction of a side cutting drill or other cutting tool in Triple TKA or Unicondylar or Bicondylar procedures. Of particular interest, the pilot drill is designed to eliminate or mitigate any deviations of the drill from its intended location and orientation as it is guided to create portals in living bone. Standard drills tend to follow the path of least resistance into and through bone often resulting in either poor drill placement, and thereby poor cutting guide placement, or improperly located and oriented portals or apertures for fixation of a cutting guide resulting in poor cutting guide placement. As shown in FIG. 44 , the pilot drill possesses cutting teeth that are very aggressive in side cutting. This is critical in that it prevents deflection of the cutting tool when it contacts tissue of varying material properties. This area of very aggressive side cutting teeth is relatively short, and is followed by a longer smooth portion of the shaft of the drill which is designed to be incapable of cutting bone, but may beneficially include smooth flutes allowing for removal of chips during the cutting process. A pilot drill of this kind, optionally used in conjunction with the Surg Nav Drill Guide of FIGS. 8 through 11 , would be outstanding for use in creating the apertures in bone desired for positioning any number of cutting guides. Specifically, the pilot drill may provide sufficient accuracy and precision of aperture creation to allow for drilling all the way through or across a bone to which a cutting guide will be attached to bone sides of the aperture as shown in FIG. 68 , where the cancellous bone within the cortical shell is not shown for the sake of clarity. [0028] In use with the embodiment of the present invention, with the soft tissue protection sleeves of the milling handle in contact with a bone surface, the pilot drill would be plunged through the bushings of the milling handle and across the joint, as shown in FIGS. 45 through 51 . FIG. 51 represents the pilot drill having been plunged entirely across the joint, but with the milling handle not shown for the sake of clarity. Thus, a portal has been created across the entirety of the joint for subsequent insertion of the side cutting drill shown in FIGS. 52 and 53 , or any other cutting tool. It should be noted that in embodiments adapted for use in Unicondylar knee replacement, it would only be necessary to create the portal in one side of the joint for extension of the cutting tool across only a single condyle (as is seen in comparing FIGS. 78 and 80 ). An alternative embodiment and method of the milling handle of the present invention represented in FIG. 54 would be to extend the side cutting drill, or other cutting tool, through a soft tissue portal on one side of the joint, across the entirety of the bone surfaces to be resected or cut, but not extend the tool through the soft tissue on the far side of the joint. As control of the side cutting drill by the milling handle is very robust, even when it supports only one spindle of the side cutting drill, accurate and precise preparation of the distal femur can be performed without necessitating a second soft tissue portal, and the soft tissue trauma associated with it, no matter how minor, on the far side of the joint. [0029] Alternatively, a hybrid embodiment of externally and internally located guide surfaces would allow for high precision, high accuracy cutting without necessitating the creation of soft tissue portals for insertion of the cutting tool. This embodiment of the present invention can be attained by positioning one PBR cutting guide surface(s) in the wound (perhaps looking like the medial guide surface of the cutting guide shown in FIGS. 68 through 70 ) and interconnecting it with an externally located PBR cutting guide surface(s) (for example, looking like the laterally located plate in FIG. 60 ). This would allow for single spindle guidance of the side cutting drill or other cutting tool in a very robust manner, while minimizing the trauma to soft tissues necessary to implement these embodiments. Furthermore, the use of these single spindle embodiments lend themselves to easy manipulation of the cutting tool in pivotally sweeping (see FIG. 85 ) a cut surface while manipulating the cutting tool axially with respect to the milling handle. Thus the anterior chamfer cut, distal cut, and posterior cut could be completed by sweeping the cutting tool along the cutting path of the cut surface, and the anterior and/or posterior cuts could be completed by pivotally sweeping the cutting tool as mentioned above while maintaining the stability inherent in guiding the milling handle on guide surfaces on opposing sides of the cut being created. This is beneficial in that the internally located guide surfaces could be truncated or shortened significantly allowing for both easier insertion into the surgical exposure and reduction in the exposure necessary to accommodate the embodiments in clinical use. [0000] FIGS. 5 through 11 [0030] FIGS. 5 through 11 concentrate on alignment guide and/or drill guide techniques. FIG. 5 shows a manually operated alignment guide suitable for use with surgical exposures similar to that shown in FIG. 2 (it should be noted that surgical navigation sensors could be used to assist in determining final drill guide location and orientation). FIGS. 6 and 7 show an improvement upon the embodiment shown in FIG. 5 for enabling manual alignment guide use in less invasive incisions by providing soft tissue accommodating contours or reliefs. In other words, for a medial parapatellar incision, the alignment guide is configured to allow for appropriate contact and referencing of the distal and posterior femoral condyles, the IM canal (when not relying on an extramedullary reference or inference of the mechanical axis) or IM Rod, the anterior cortex or anterior runout point of a given or proposed implant size (via a stylus not shown), and the epicondylar axis via palpitation or visual reference while the patellar tendon, patella, and/or quadriceps tendon is draped over the lateral side (right side as shown in the figures) of the alignment guide allowing insertion of the guide when the patella is neither everted not fully dislocated as in conventional techniques. It should be noted that initial alignment indicated by reference of the distal femur may be further adjusted in all six degrees of freedom as a fine tuning for final cut location and orientation. This simply calls for the inclusion of additional adjustment of the location and orientation of the crossbar mechanism and/or rotational alignment arm, with respect to the initial reference provide for by contact between the body of the guide and the bone (optionally including the IM Rod), in flexion-extension angulation, varus-valgus angulation (rotational angulation and Anterior-Posterior location are already shown), mediolateral location (represented in this embodiment of the current invention by the cross bar mechanism in FIG. 5 where drill guide mediolateral location is shown as being independently and infinitely adjustable), and proximal-distal location (as shown in FIGS. 5, 6 , and 7 —it should be noted that this adjustment might be best embodied in an infinitely adjustable slide as opposed to the incrementally adjustable slide shown, and that simple marking would be present indicating the relative movement of the slide with respect to the body). It may be desirable to only utilize only a medial drill guide plate with multiple drill guide bushings to create holes extending partially or completely across the femur depending upon the manner in which the guides are to be connected to the femur. [0031] FIGS. 8, 9 , and 10 show an alternative alignment/drill guide embodiment of the present invention wherein a cannulated surgically navigated handle/drill guide is used to create fixation apertures in the bone for direct or indirect fixation of a cutting guide. As shown in FIG. 8 , it may be advantageous to include tines for penetrating the bone to obtain initial stabilization of the handle in the location and orientation indicated by the surgical navigation system (“Surg Nav”—this term shall be used interchangeably with Computer Aided Surgical System or Image Guided Surgical System throughout this disclosure) prior to extending the drill, represented in FIG. 10 , into the bone to create the aperture. It should be noted that the aperture, or hole, thus created could be blind or extended to a specific depth, or optionally extended entirely through the bone and out the furthest side of the bone. Importantly, this process could be utilized transcutaneously through a small stab wound (perhaps 4 mm in length) through the skin to the bone surface, or through a preformed incision through which other instrumentation of the present invention or other devices may be introduced during a procedure. Further, although only one cannulation is shown, a single handle may desirably contain multiple cannulations, some or all of which could be adjustably extended into contact with the bone to reduce any wandering of the drill contacting oblique bone surfaces and improve the precision and accuracy of aperture creation (thus allowing for the creation of apertures in the medial side of the femur, represented in FIG. 11 , with a single Surg Nav Handle—Also, the apertures may be configured such that the femoral and tibial apertures shown in FIG. 11 are all created using a single positioning step for the handle). As represented in FIG. 9 , there is very little distance over which the drill is cantilevered between its guidance within the cannulations and its point of initial contact with the outer surface of the bone. This aspect of this embodiment of the current invention is critical in preserving the potential accuracy of Surg Nav systems, i.e.; the navigation system (the computer and the sensors) may be capable of determining appropriate location and orientation to ±0.1 mm and ±0.5 degrees, but if the location and/orientation of the aperture created represents some path of least resistance in bone which is followed by the drill, the resultant location and orientation of cut surfaces, and thereby the location and orientation of the prosthesis attached thereto, will likely be seriously in error. [0032] It should also be noted that the methods described herein are applicable to the methods demonstrated in Provisional Patent Application Ser. No. 60/536,320, entitled “Methods and Apparatus for Pinplasty Bone Resection” and Ser. No. 60/xxx,xxx, entitled “Methods and Apparatus for Wireplasty Bone Resection,” the disclosures of each of which are hereby incorporated by reference. [0033] It should also be noted that another embodiment of the present invention, represented in FIGS. 88-92 , benefits from the apparatus and principles of operation outlined above. As shown in FIG. 88 , an aperture and a plane are created in bone which actually act as the cutting guide in controlling the location and orientation of the cutting tool within a specific plane during the creation of a cut surface. In this embodiment of the present invention, the cannulated drill guide will, in either manual or Surg Nav techniques, be used to guide a forstner style drill bit (the ‘guide surface’ shown in FIG. 88 could have been created by a modified drill with a leading section 15 mm long by 4 mm in diameter, responsible for the pivot aperture, and a 10 mm diameter following section which was about 10 mm long, responsible for the pivot reference surface) to create a larger diameter cylindrical aperture the bottom of which would define a pivot reference surface parallel to the cut surface to be created, and a smaller diameter cylindrical aperture to form a pivot aperture for maintaining the body of the bushing shown in FIGS. 88-91 in the proper location and orientation while cutting. Importantly, the technique outlined above is beneficially applied to tibial resection or any other planar or curvilinear resection technique as well. [0000] FIGS. 12 through 34 [0034] FIGS. 12-34 disclose embodiments of the present invention for creating planar and/or curvilinear resection surfaces on or in the proximal tibial and other bones and embodiments of the present invention for prosthetic implants. [0035] FIGS. 12-15 represents an embodiment of the present invention for cutting guides and cutting tools which substantially comprises a guide with guide pivot aperture(s) and a guide pivot reference surface(s) for mating with a bushing controlling a cutting tool, wherein the bushing possess a bushing reference plane (which mates with the pivot reference surface(s) of the guide), a bushing pivot pin, best represented in FIG. 88 (which mates with the guide pivot aperture(s) of the guide), and a cannulation for articulated and/or axial guidance of the cutting tool. [0036] There are a number of optional features that are highly desirable depending on the preferred method of use utilized for these embodiments of the present invention. The soft tissue protection tip of the cutting tool and the integral soft tissue retractor feature of the bushing body are two principal examples represented in FIG. 20 . The soft tissue protection tip can be integrally formed as a part of the cutting tool during its manufacture, be a separate component attached to it, and may, in one preferred embodiment, be free to rotate with respect to the cutting tool (which would be useful in preventing rotating bearing contact between the tip and soft tissue). The integral soft tissue protector in beneficial in preventing or mitigating contact between soft tissue near the area where the cutting tool enters, cuts, and exits the wound (in other words, to the right and left of the bushing body shown in FIG. 13 ). If you picture the incision as being a window into the joint which is somewhat elastically moveable from side to side, the integral soft tissue retractor would act to shift that window to mitigate or prevent contact between the soft tissue (specifically the patella tendon, medial or lateral collateral ligaments, the capsule, skin, fat, etc.) and the cutting surfaces of the cutting tool. [0037] In operation, the guide is properly positioned with respect to the proximal tibia and the cut to be created thereon and robustly fixed with respect to the tibia or directly to the tibia. This can be accomplished by manual alignment means outlined in U.S. Pat. No. 5,643,272 for manually positioning guides then fixing them in place, or use the '272 apparatus and methods to create the fixation apertures shown in FIG. 11 or 12 , or use the Surg Nav techniques described herein as shown or in conjunction with the methods described in the '272 patent. The bushing body is then engaged with the guide. Three primary methods of initiating cutting of the proximal tibia are preferred. The first, or ‘Tangent Method’, is initiated by extending the side cutting drill through the bushing body cannulation and into contact with a side of the tibia and then sliding the optional non cutting tip along the face of the bone until the cutting surfaces of the cutting tool were first in contact with the side of the bone. At this point, the cutter could be actuated to begin cutting the boney tissue to create the cut surface. As the non-cutting tip cannot cut bone, its edges would remain at all times immediately beyond and adjacent to the boundary of the cut surface being created. The diameter or size may be greater or less than the diameter or size of cutting surfaces of the cutting tool. Note that although the embodiment of the cutting tool shown is a side cutting drill, a modified rat tail rasp driven by a reciprocating driver could also work well—any cutting tool capable of cutting in a direction orthogonal to its long axis is considered to be within the scope of the present invention. [0038] As best represented in FIG. 15 , the entirety of the resected surface may be prepared in this manner. The second primary method is the ‘Plunge Then Sweep’ method. In this method, the cutting tool or optionally a pilot drill would be plunged completely or partially across the surface to be cut. Then the cutting tool could be swept back and forth in clockwise and counter-clockwise directions while being axially manipulated to complete the cuts. The third primary method is the ‘Chop Then Sweep’ method represented in comparing FIGS. 88 and 89 . In this method, the cutting surfaces of the cutting tool are positioned over and at least partially across the uncut bone, then chopped down into it by manipulating the bushing. In other words, the bushing pivot pin is engaged with the pivot aperture with the cutting tool positioned over the bone which positions the bushing reference surface at a distance above the pivot reference surface, then the bushing is moved downward along the axis of the bushing pivot pin while the cutting tool is under power until the cutting tool reaches the cut surface to be created (if the cutting tool is a side cutting drill, the cutting surfaces would be tangent to the desired cut surface at that time). The bushing is then manipulated as described hereinabove to complete the cuts. Importantly, the pivot reference surface and pivot aperture could be slidably mounted to a base component fixed with respect to the tibia so that the surgeon may manipulate the bushing body to simultaneously create the cut and move the pivot aperture with respect to the tibia. This embodiment will enable the surgeon to easily compensate for any soft tissue condition encountered clinically while preserving the benefits of the present invention. Methods combining the aforementioned primary methods are considered to be within the scope the present invention. Importantly, most standard or prior art tibial resection cutting guides may be simply modified to include the pivot apertures described herein. [0039] FIGS. 16 through 21 describe another embodiment of the present invention. As shown in FIG. 16 , this embodiment includes a Base and a Rotational/Translational Pivot Arm coacting to allow for infinite manipulation of the bushing pivot pin location within a desired plane during the process of removing material from the proximal tibia or other bone. Movement of the Rotational/Translational Pivot Arm in both rotational and translational degrees of freedom within a desired plane allows for any combination of rotational and translational movement of the axis of the bushing pivot pin within its desired plane. In other words, this embodiment of the present invention allows for infinite and continuous adjustability of cutting tool location and orientation with respect to the bone or bones being cut while providing for accurate and precise cut surface creation. [0040] FIGS. 22 through 28 represent another embodiment of the present invention whose principal of operation are similar to previous embodiments, with the exception of including a depth limiting contour which acts as either a definitive limitation for cutting tool depth or as a general guideline for a surgeon to follow as the patient's clinical presentation and the surgeon's judgment dictate. Although the embodiment shown is directed toward Unicondylar tibial preparation, it should be noted the any clinical application where such definitive or guideline type depth guidance is desirable. [0041] FIGS. 29 and 30 show an embodiment of the present invention directed toward endplate preparation in spinal reconstruction where the endplates are prepared to receive a prosthetic implant. It is interesting to note that the profile of the cutting path of the guide represented in FIG. 30 , in this embodiment, is geometrically identical to the cutting path of the resected surface created by the passage of the cutting tool shown. This could be very helpful in clinical application where such a device where inserted into a wound such that, while the surgeon could not visually observe the cutting tool while it removes boney material, he could, by way of the guide geometry, observe where the cutting is with respect to the bone being cut by looking at the position (represented by “POS 1 ” and “POS 2 ”) of ‘Pivot 2 ’, represented in FIG. 30 , with respect to its location in contact with the guide as it traverses the cutting path of the cutting guide. This embodiment is also highly applicable to tibial resection and could allow for cut geometries that are anatomically curved in both AP and ML profiles to both preserve bone and improve fixation quality and load transfer characteristics between the implant and the bone by converting the shear component load of conventional planar tibial components into compressive loads via geometrically normal or transverse abutment of bone and implant surfaces in the direction of A-P and/or M-L and/or torsional shear loading. An implant design embodying fixation geometries for mating with such cut surfaces is highly desirable. In one embodiment of such a tibial prosthesis design, the fixation surfaces would be intended to mate, directly or indirectly, with cut surfaces represented in FIGS. 33 and/or 34 (the tibia in the right side of the FIG. 34 ). In essence, the tibial implant would possess a planar or gently curvilinear ‘rim’ for contacting the ‘cortical skim cut’ surface (represented in FIG. 32 ), and convex fixation surfaces for direct or indirect fixation to the concave tibial cuts represented in FIGS. 33 and 34 . Direct fixation to such surfaces could be achieved by high precision resection of both the cortical rim, for attachment of the rim of the tibial prosthesis, and the concave surface(s), for intimate apposition to the convex implant surfaces. Such fixation, specifically of the concave bone cuts to the convex implant surfaces, could be achieved by way of an interference fit between the cuts and the implant along one axis (for instance, a front to back—AP—axis or direction), or along two axes (for instance, AP and Side to Side—ML—axes), or circumferentially (in other words a bit like a pin of a given diameter being forced into a hole of a lesser diameter), or both circumferentially and along an axis at roughly a 90 degree angle or normal to the skim cut surface when viewed in one or two orthogonal planes (an “up and down axis” or superior-inferior or proximal distal direction). It should be noted that an interference fit in a roughly superior-inferior direction may call for a textured surface on the bottom most surface of the convex fixation surfaces presents a small surface area of contact at initial contact with the bottom of the concave cut to allow the implant to compact a reduced area of cancellous bone as the implant is impacted in a superior to inferior direction until it reaches its desired superior-inferior location and/or contact between the rim of the implant and the skim cut of the cortices. As compared to previous methods of achieving implant fixation, these embodiments of the present invention yield superior stability of implant fixation to bone to an extent reminiscent of the difference between riding a horse wearing a deeply dished saddle and riding a very sweaty horse bareback. [0042] An alternative fixation paradigm allows for less intensive demands for the precision of the fit between concave tibial cuts and convex fixation surface. In essence, the concave surface may be ‘excavated’ in any desired manner (such as the Cutting Trials shown in FIG. 31 which cut the proximal tibia while the tibia is moved through at least a portion of its range of motion about the femur), and a morselized or granular osteobiological substance, perhaps tricalcium phosphate, HATCP, or other substances generally described as ‘bone substitutes’ or autograft or allograft cancellous or cortical bone (it would be very useful to use the bone which was removed from the tibia or other patient bone during the creation of the cut(s) in that it is readily available and completely avoids the issues of disease transmission or immune response), is then impacted into the concave surface using a ‘form’ to create a surface of impact material (referred to herein as the “Impacted Surface”) of specific shape and location/orientation with respect to the cortical skim cut and/or the tibia or femur. This form is beneficially shaped in a manner related to the shape of the convex implant fixation surface shape so as to create a specific geometric relationship between the implant fixation surfaces and the Impacted Surface geometry. In one embodiment of the present invention, the fit between the implant and the Impacted Surface would be an interference fit or press fit. As properly impacted morselized cancellous bone is known to achieve stiffnesses (or modulus of elasticity) which approach as much as 80% of the stiffness of cortical bone in compression, robust intraoperative fixation may be achieved in this manner. In another embodiment, the fit would leave a significant gap, perhaps 0.2 mm to 4.0 mm in width, between portions or all of the convex fixation surfaces of the implant and the convex cut(s), into which bone cement or other substance would then be injected or impacted achieving interdigitation with both the surfaces of the prosthesis and the material of the Impacted Surface. This results in what could be described as composite interface of both biologically active and non-living but structurally robust materials to facilitate both immediate intraoperative stability by way of simple mechanics and long term stability by way of improved load transfer between the implant and the bone eliciting a beneficial biological response by the bone to said loading resulting in intimate and mechanically robust apposition between the composite interface and living tissue. It should be noted that such a method prevents excessive micromotion or strain at the interface between the implant (and/or the composite interface) and living tissue during the postoperative healing process, which, in essence, gives the bone a chance to further stabilize its fixation to the implant by way of bone modeling or remodeling in response to load transfer. Specifically, it is highly beneficial to maintain the strain state within living bone at and/or in the general vicinity of the bone implant interface within a range of 50 microstrain to 4000 microstrain so as to elicit the formation of bone tissue at and around the interface—strain levels in excess of 4000 microstrain or less than 50 microstrain are very likely to elicit the formation of fibrocartilagenous tissues at the interface which may lead to aseptic loosening of the implant. In the embodiment where the bone cement is injected, a small hole located at or beneath the skim cut allows for the injection of the material beneath the implant to achieve intimate and controlled interdigitation. [0043] Alternatively, the implant could be seated ‘over’ the freshly cut concave surfaces, and a slurry of biologically active and/or mechanically robust material(s) injected into the gaps between the implant and the bone under controlled pressure. Injection could be achieved via the portal shown in FIG. 34 . Such a slurry may comprise a mixture of substances such as morselized patient bone and bone cement, but alternative or additional materials including bone substitutes, osteobiologicals such as bone morphogenic proteins, antibiotics, or even living cells such as T cells known to promote post-operative healing and long term implant fixation. Beneficially, a fin feature may be added to these embodiments to facilitate additional mechanical stability, and said stem feature could beneficially possess an aperture for cross-pin fixation as described below for use in conjunction with the cross pins represented in FIG. 111 . [0044] Importantly, it is an objective of the embodiments of the present invention to preserve living, structurally viable bone tissue to facilitate the efficacy of any subsequent revision procedures. Further, the location and geometry of the concave tibial cut allows for the use of a bearing insert (conventionally made of materials such as polyethylene or other materials capable of ‘whetting’ or mimicking the benefits of ‘whetting’ during bearing contact; mimicking constituting, in one embodiment, the absence or mitigation of wear debris generation despite the application of significant bearing forces, in TKA in excess of 200 lbs and often as much as 500 lbs or more) whose ‘underside’ is convexly shaped to mate with a concavely shaped mating or accommodating surface in the upper surface of the tibial implant or ‘baseplate’ as it is sometimes referred to. This allows for a tibial insert(s) whose thickness, in the areas beneath where the femoral implant bears against the tibial insert, may be equal to or greater than those insert thicknesses used in the past (those associated with predominantly planar tibial cuts) while require removal of significantly less structurally viable bone from the cortical rim of the proximal tibia than past efforts. Determination of the geometry and location of the baseplate's concave surface and therefore the areas of greatest insert or bearing surface are easily determined by analysis of the wear patterns of retrieved tibial inserts. These embodiments of the present inventions also facilitate significant clinical benefits when applied to meniscal or rotating platform TKA designs as a high degree of conformity may be achieved while constraint is mitigated while preserving significantly more bone than prior art devices. Further, the reproducibility of the methods and apparatus described herein enable independent attachment of single compartment implants to bone to achieve Unicondylar, Bicondylar, Bicondylar and Patellofemoral, or Unicompartmental and Patellofemoral replacement of damaged bone surfaces while achieving the objectives of bone preservation, robust immediate and short and long term fixation, reproducibility of implant fixation and resulting location and orientation, and intraoperative ease of use. [0045] It should be noted that the cutting profile of the cutting tool shown in FIG. 29 may be curved in manner beneficial to endplate preparation in intervertebral fusion, dynamic disc replacement, and/or nucleus replacement as the cutting profile closely approximately the natural geometry of the endplates and provides for intimate fit with such prostheses fixation surfaces. In adapting this embodiment to tibial resection in either partial or complete knee replacement, the cutting profile of the tool would be shaped as desired to create the aforementioned cut surfaces in either one continuous movement of a single cutting tool, or incremental use of one or more cutting tools to cut bone to the desired shape and in the appropriate location and orientation, in all degrees of freedom, with respect to the tibia and/or femur and/or patella and/or soft tissues of the knee joint. [0046] Critically, in many applications of the tibial resection embodiments and methods described herein it is desirable that the Superior-Inferior thickness or diameter of the cutting tools used be less than the thickness of the bone to be removed in the creation of the cut surfaces so that the cutting surfaces of the cutting tool not contact soft tissue surface and bone surfaces located above the bone being removed. Alternatively, the cutting tool could be of such a thickness or diameter as to allow for the resection of both the femur and the tibia, or any such contiguous bones, to be prepared simultaneously with the passage of the cutting surfaces of a single tool across or along cut surfaces being created on both bones. Maintaining the desired geometric relationships between the contiguous or adjacent bone ends would be key in this embodiment of the present invention and could easily be obtained and maintained by use of a bracket fixed to the bones to establish and maintain the geometric relationship between said bones (see FIG. 30 for one embodiment of such a bracket employed to establish and maintain alignment between adjacent vertebral bodies. [0000] FIGS. 35 through 40 [0047] FIGS. 35 through 40 show embodiments of the present invention for femoral resection. For the sake of clarity, it should be noted that any combination of the forms of the present invention disclosed herein may be modified or combined to form constructs not specifically disclosed herein, but still within the scope of the present invention. The embodiments represented in FIGS. 29 and 30 are outstanding examples of this, as one of ordinary skill in the art would clearly recognize the applicability and benefits of this embodiment for tibial and/or femoral resection in Unicondylar or Bicondylar procedures, for bone resection in ankle replacement or arthrodesis (fusion), mandibular advancement procedures, high tibial osteotomy procedures, proximal femoral and acetabular preparation in Hip Arthroplasty, and many other applications where reproducible and safe removal of living tissue during surgical intervention is beneficial. [0048] FIGS. 35-40 shows an embodiment of the present invention wherein the guide plates and guide surfaces are located entirely outside the wound, but the side cutting drill and handle construct are not passed through mediolateral soft tissue portals described hereinabove. The side cutting drill controlling portion of the handle is essentially ‘snaked’ into the less invasive wound/exposure/approach/incision and the guide engagement features are engaged to the cutting guide at a location entirely outside the wound. As long as the axis of the engagement feature is maintained as coaxial with the side cutting drill, the desired cut geometries will be attained despite manipulation of the handle with respect to the guide. This method can be utilized to complete some or all of the desired cuts. Also, this embodiment of the current invention can be used to perform the posterior cut, posterior chamfer cut, and distal cut optionally using kinematic resection to reduce exposure requirements, and then removed from the wound and guide, flipped over 180 degrees from the orientation shown in FIG. 39 , reinserted into the wound and into engagement with the guide to cut the anterior chamfer cut and anterior cut with or without implementation of a kinematic resection technique and, optionally, with the knee in 15 degrees to 45 degrees to facilitate the soft tissue laxity and ease of use previously described. It should be noted that the mechanism for driving the side cutting drill is not represented in these figures and that a number of different options may be used. One way to accomplish drive input is generically represented in FIG. 40 , where a flexible drive shaft or bevel gear arrangement may be utilized to drive the side cutting form drill shown. Alternatively, chain, belt, or pneumatic drive mechanisms may also be used. FIG. 40 also represents an embodiment of the present invention which allows for the accurate and precise preparation of curvilinear cut surfaces, beneficially used in conjunction with guides containing curvilinear guide surfaces as represented in FIGS. 61 and 62 , to create cut surfaces for intimate attachment and fixation to implants represented in FIGS. 125, 126 , and/or 127 . [0049] FIGS. 93 through 98 represent an implementation of the side cutting drill embodiment of the present invention for cutting tools. It is of interest to note that the milling handle shown could further be guided by the PBR guides of the present invention to further combine the accuracy and precision benefits of PBR with the soft tissue protection characteristics of tibially embedded femoral cutting tool. It should also be noted that the side cutting drill with a curved cutting profile, similar to that shown in FIG. 119 , could also be used to attain cut geometries possessing simultaneously curved or curvilinear cutting profiles and cutting paths. In utilizing such, it would be critical that the side to side location of the cutting profile of the cutting tool be tightly controlled with respect to the desired side to side location of the implant as the side to side location of the implant would be dictated by the cut surfaces generated. Alternatively, a cutting tool with a linear cutting profile, as shown in FIG. 94 , could be utilized to create cut surfaces with a linear cutting profile and a curved cutting path, and then a second cutter with a curved cutting profile could be used to create a second, contiguous or noncontiguous, cut with a curved cutting profile and/or path whose mediolateral location was closely controlled to result in proper fit and location of the prosthesis attached to said cut surfaces. It should be noted that the cutting path of the second cutter could be located within a single plane, such as for a bilateral femoral component design, or could be curvilinearly divergent from the plane containing the cutting path of the first cut surface. This would be useful for unilateral femoral component designs (ones which require separate left and right femoral implants) so as to allow for the implant design to reflect out of plane patellofemoral kinematics and/or out of plane tibiofemoral kinematics most accurately. [0050] Interestingly, this embodiment of kinematic resection style resection could be modified to allow the cutting tool to be directly or indirectly linked to the movement of the patella with respect to the femur, or directly connected to the patella, to enable cutting of patellofemoral articular surfaces on the femur while moving the tibia and patella through ranges of motion about the tibia. The embodiments of cutting tools for use in attaining this include curvilinear end cutting mills or face cutters, side cutting drills with linear or non-linear cutting profiles, and other cutting tools capable of cutting the femur while engaged, directly or indirectly, to the patella. The side-to-side location of such cutters could be determined by engagement or adjustment with respect to a PBR or other guide, or simply by the natural kinematic path of the patella about the femur during flexion-extension of the knee joint. [0051] The complete disclosures of the patents, patent applications and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that this invention is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the invention intended to be limited only by the claims set forth herein.

Milling and drilling tools and soft tissue management techniques are provided for arthroplasty that facilitate intraoperative and postoperative efficacy and ease of use. In one embodiment, resiliently biased soft tissue protective sleeves surround a side cutting tool and are interposed along the longitudinal axis of the cutting tool, preferably adjacent each side of the bone. The soft tissue protective sleeves are biased to track along the contour of the side of the bone and prevent the cutting tool from being exposed to soft tissue during the resection. In another embodiment, a pilot drill is initially utilized to create an initial bore in the bone to be resected. The pilot drill preferably has an end cutting arrangement and a non-cutting removal channel that minimizes the tendency of the pilot drill bit to drift off-axis as the initial bore in the bone is created. Once the initial bore is created, the pilot drill bit is withdrawn and a second side cutting tool, such as a milling bit, is then inserted into the bore to perform the desired surface resection.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to a material on hand checking method in inventory, and particularly a method that is capable of checking material shortage status of trial-run prototypes/modules applied to an inventory management system in the manufacturing industry. [0003] 2. Related Art [0004] To most enterprises and product manufacturers, there are many ways to increase profit margins, and managing costs is one of the ways. Moreover, management of material costs among cost categories is a matter of interest to enterprises. To satisfy required product quantities by customers or end users, those enterprises and product manufacturers have to prepare sufficient materials maintaining normal processes of productions. In default of maintaining sufficient stock inventory would suspend operations of production lines, so that finished goods from productions can not be delivered on time. This may lose potential commercial opportunities, cause the imbalance between supply and demand (disequilibrium), or reduce, even lose, market shares to those enterprises and product manufacturers. On the contrary, overstocks would cause a hoard of cash funds, difficulties in circulating capital and increase in management of costs, and the loss of margin profits from invisible risks of changeable product markets to those enterprises and product manufacturers. [0005] Daily faced problems to the manufacturing industry include: what parts or components need to be purchased, how to plan production schedules after purchasing material items, how to arrange delivery of finished goods from productions, how to manage excess/surplus stock, etc. For example, capacity forecast and formal orders are not the same thing, even a formal order would possibly change without any previous notice. Therefore, it is often to cause loss due to a stock-out or excess/surplus stock resulting from mistaken list making and incorrect materials preparation. However, current Material Requirement Planning (MRP) still has the following drawbacks: actual build orders (production orders) and build orders (production orders) for trial-run prototypes/modules are simultaneously sent to the system. Nevertheless, the system can not distinguish actual build orders from trial-run build orders. Where there is any material shortage, there is a superfluity of material purchase to increase inventory, instead of notifying purchase staff of making certain material purchase. As there is no much need of demands and production orders for most trial-run prototypes/modules, the Material Requirement Planning (MRP) system is unlikely to forecast quantities of required materials, but depends on rule of thumb of stock clerks to estimate quantities of required materials and bills of material (BOM). The Material Requirement Planning (MRP) system then issues required materials from inventory center/stock house according to an estimated sum. This kind of method takes too much cost of time and labor. [0006] Hence, material on hand checking method of trial-run prototypes/modules in the manufacturing industry has become a heavily focused subject. SUMMARY OF THE INVENTION [0007] In view of the foregoing, the invention aims at resolving the preceding disadvantages to provide a material on hand checking method of trial-run prototypes/modules. The primary object of the invention is to aim at proceeding quantity forecasts of required materials for trial-run prototypes/modules through the Enterprise Resource Planning (ERP) server of the enterprise end to manage inventory in the facilities. If there is any shortage, the Enterprise Resource Planning (ERP) server would make a marker and store it back to the storage media. Moreover, the Enterprise Resource Planning (ERP) server notifies managers that material on hand is only required for trial-run prototypes/modules. This further achieves the goal of heightening profits of enterprises by decreasing the risk of material purchasing and reducing a hoard of inventory. [0008] The disclosed material on hand checking method of trial-run prototypes/modules according to this invention at least consists of: receiving at least one build order through the Enterprise Resource Planning (ERP) server, determining if the build order is for a trial-run prototype/module through the Enterprise Resource Planning (ERP) server, transferring the build order back to a storage media according to the Enterprise Resource Planning (ERP), exploding bill of material (BOM) of the build order through the Enterprise Resource Planning (ERP) server, and integrating the bill of material (BOM) and storing it back to a storage media through the Enterprise Resource Planning (ERP). [0009] The foregoing, as well as additional objects, features and advantages of this invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. Specific structures and functional details disclosed hereunder are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. BRIEF DESCRIPTION OF THE DRAWINGS [0010] [0010]FIG. 1 is a schematic representation of material on hand checking method of trial-run prototypes/modules of this invention. [0011] [0011]FIG. 2- a is a flowcharted representation of material on hand checking method of trial-run prototypes/modules according to this invention. [0012] [0012]FIG. 2- b is a sub-flowcharted representation of exploding bills of material (BOM) according to this invention. [0013] [0013]FIG. 3 is presently known exploded view of bills of material (BOM) of the information system. [0014] [0014]FIG. 4 is an exploded view of bills of material (BOM) according to this invention. DETAILED DESCRIPTION OF THE INVENTION [0015] This invention proposes a material on hand checking method of trial-run prototypes/modules. In particular, the method, based on the advocacy of the up-to-date Business Process Re-Engineer (BPR), mainly aims at improving effective utilization and management of enterprise resources and re-engineering working processes of managing and checking material quantities of trial-run prototypes/modules. This is to decrease the risk of overstock and to reduce operation costs of the organization. [0016] Prior to this invention, the introduction of production process of a notebook computer for showing the importance of trial-run prototypes/modules is described hereunder. [0017] The production process of a whole new notebook computer (laptop) generally comprises two phases, one is research and development (R&D) and trial-production (trial-run) phase, and the other is quantity-production phase in the factories. This production process pattern is almost applied to all electronic products. The details are as follows. [0018] A. R&D and trial-production (trial-run) phase: [0019] 1. Market information collection: both R&D and marketing departments collect market information to analyze the feasibility of a new product and to decide specifications of that product. [0020] 2. Prototype/module design: product specifications, such as PCB (printed circuit board) design, parts and components, materials, and outlook, are delivered to designers of relevant departments for detailed design. [0021] 3. Prototype/module testing: sections of original prototype/module design are tested for defects and instant rectification. [0022] 4. New production lines for trial-run prototype/module: that modified prototype/module would be delivered to facility to create sections of the prototype/module and to factories/manufactories for productions. All improper design, especially the PCB part, would be re-rectified during the process of trial-production. Also, there are various testing for the new product to be forthwith rectified to heighten feasibility for productions on trial-production phase. However, the system is unable to estimate quantities of parts and components and provide materials with accuracy, even if the trial-run prototype/module had passed all kinds of testing and whole production process had been determined. The reason is that some of parts and components on the bill of material (BOM) of a trial-run prototype/module are, as often as not, duplicate with that of other different prototypes/modules. Besides, the trial-run prototype/module only needs quite small quantities of required materials. Therefore, either there is no material being issued by the system, or overstock from purchasing makes a hoard of inventory. [0023] B. Quantity productions phase in the factories/manufactories: [0024] Once a trial-run prototype/module passed the trial-production phase without any problems in production process and product usage, the trial-run prototype/module would be able to be distributed to production lines in the factories/manufactories for quantity-productions. [0025] The aforementioned indicates the importance of the process of trial-productions in the manufactory industry. [0026] The feasibility and practicality of this invention will be elaborated by means of an embodiment depicted in the following. With reference to FIG. 1, the schematic representation of material on hand checking of trial-run prototypes/modules of this invention illustrates details as follows. [0027] First, after determining a trial-run prototypes/modules, the Enterprise Resource Planning (ERP) server 100 of the enterprise end integrates and manages all material resources in the enterprise end, captures stock data from a storage media 110 . There are various material stocks and finished goods in different facilities 50 a˜n, among which all stocks can be analyzed and contrasted with quantities of required materials between the stock house/inventory center and the trial-run prototype/module by the Enterprise Resource Planning (ERP) server 100 . As there is actual demand and production order for the trial-run prototype/module, such a build order 10 , therefore, can be directly placed into the Enterprise Resource Planning (ERP) server 100 for calculation. This is different from conventional known trial-run prototypes/modules of no demands and production orders. According to the build order 10 , the Enterprise Resource Planning (ERP) server 100 can explode the bill of material (BOM) 80 of the trial-run prototype/module before calling inventory status on the storage media 110 for item-by-item contrast. The Enterprise Resource Planning (ERP) server 100 then finds part numbers of stock-outs through a searching method to make a marker for decision-makers references. [0028] With reference to FIG. 2- a, the flowcharted representation of material on hand checking method of trial-run prototypes/modules according to this invention represents the detail hereunder. [0029] First, the Enterprise Resource Planning (ERP) server 100 receives at least one build order (step 200 ), and the information of a trial-run prototype/module comprises at least: the facility 50 and required quantity of the trial-run prototype/module. After receiving the build order, the Enterprise Resource Planning (ERP) server 100 determines if the build order 10 is for a trial-run prototype/module (step 210 ). If the build order 10 is not for a trial-run prototype/module, the facility 50 implements the build order 10 (step 215 ). If so, the Enterprise Resource Planning (ERP) server 100 transfers the information of the build order 10 back to a storage media 110 (step 220 ), which provides a plurality of columns to store different contents. The Enterprise Resource Planning (ERP) server 100 then explodes the bill of material (BOM) of the build order (step 230 ). When the bill of material (BOM) is completely exploded, the Enterprise Resource Planning (ERP) server 100 integrates the bill of material (BOM) and stores it back to the storage media 110 (step 240 ) and terminates the function flow of the material on hand checking method. The way for the Enterprise Resource Planning (ERP) server 100 to integrate the bill of material (BOM) 80 is to calculate quantity of available stock for the trial-run prototype/module from the quantity difference of inventory stock and reserved stock. The way for the bill of material (BOM) 80 stored back to the storage media 110 is to store part numbers and quantities of stock-outs for trial-run prototype/module into the columns provided by the storage media 110 for decision making purposes. [0030] The aforementioned exploding bill of material (BOM) method of the trial-run prototype/module refers to FIG. 2- b, the sub-flowcharted representation of exploding bills of material (BOM) according to this invention. [0031] First, the method is to explode all bills of material (BOM) of trial-run prototypes/modules (step 231 ), then combine components or parts at the first level of bill of material (BOM) (step 232 ). When the first level of bill of material (BOM) is completely combined, then the method explodes components or parts at the first level of bills of material (BOM) (step 233 ). When the first level of bill of material (BOM) is completely exploded, the method then combines components or parts at the second level of bill of material (BOM) (step 234 ). When the second level of bill of material (BOM) is combined, the method then explodes components or parts at the second level of bill of material (BOM) (step 235 ). Repeating the above process of combining and exploding the bill of material (BOM) until the last level of bill of material (BOM) is completely drilled down (step 236 ). [0032] The above mentioned bill of material (BOM) 80 can be a product tree of an enterprise and further comprises at least one common material and at least one specific material. The meanings of specific materials and common materials are: the specific materials are specified components or parts needed for respective prototypes/modules, no components and parts among which are overlapped in common; the common materials relate to general components or parts needed for all prototypes/modules, and are evaluated by pre-set columns through the Enterprise Resource Planning (ERP) server. [0033] [0033]FIG. 3 is a presently known exploded view of bills of material (BOM) that illustrates the exploding method of bill of material (BOM) as follows, [0034] First, the system explodes the first level of bill of material (BOM) of prototype A (material modules C, D, and E), then explodes the second level of bill of material (BOM) (material modules H, I, I, J, and K). At the second level of bill of material (BOM) there is a material module I being repeatedly exploded, as material module I belongs to parent material module C, as well as parent material module E. Finally, the system drills down to the third level of bill of material (BOM) (material modules L, M, N, and O). At the third level of bill of material (BOM) there are material modules L and M being repeatedly exploded. As both L and M belong to parent material module I, which is one of sub-components to its parent material modules C and E, thus module I is repeatedly exploded. [0035] After prototype A is exploded, the system then begins to explode the first level of material (BOM) of prototype B (material modules C, F, and G), then explodes the second level of bill of material (BOM) (material modules H, I, I, and J). At the second level of bill of material (BOM) there is a material module I being repeatedly exploded, as material module I belongs to parent material module C, and also belongs to parent material module F. Finally, the system drills down the third level of bill of material (BOM) (material modules L, M, L, M, and P). At the third level of bill of material (BOM) there are material modules L and M being repeatedly exploded, as both L and M belong to parent material module I, which is one of sub-components to its parent material modules C and F. The exploding process, therefore, is completed. [0036] [0036]FIG. 4 is an exploded view of bills of material (BOM) according to the disclosed invention that illustrates the exploding method of bill of material (BOM) as follows. [0037] The exploded method of this invention: first, the system explodes all bills of material (BOM) of respective prototypes (prototype A and B, for example), combines the first level of bills of material (BOM) of both prototypes A and B, and then explodes the first level of bills of material (BOM) (material modules C, D, E, F, and G), followed the first level of bill of material (BOM) of both prototypes A and B being completely combined. When the first level of bills of material (BOM) of both prototypes A and B are exploded, the system drills down to the second level of bill of material (BOM) to combine bills of material (BOM) of both prototypes A and B. The system then explodes the second level of bill of material (BOM) (material modules H, I, J, and K), followed the second level of bills of material (BOM) being completely combined. When the second level bills of material (BOM) of both prototypes A and B are exploded, the system drills down to the third level to combine bills of material (BOM) of both prototypes A and B. The system then explodes the third level of bill of material (BOM) of both prototypes A and B (material modules L, M, N, O, and P). The exploding process is, therefore, completed. [0038] Hence, the exploded method of bill of material (BOM) consists of the following steps: first, exploding all bills of material (BOM) of respective prototypes, then stratifying all levels of bills of material (BOM), according to assemble features of respective prototypes. Finally Combining and exploding components or parts at each level of all integrated bills of material (BOM). [0039] This exploded method can largely reduce the burden to the system resources, enhance efficiency, and enable material management and distribution more effective. [0040] In sum, conventionally known method of exploding bills of material (BOM) has to repeatedly explode material items to match the tree structure of bills of material (BOM). Take material module M as an example that it has been exploded for four times, and it heavily occupies the hardware space and wastes the time for exploding. Therefore, this disclosed invention utilizes combination method to explode bills of material (BOM) for the following advantages that, [0041] 1) Each material is exploded only once to save time in exploding bills of material (BOM); [0042] 2) Common materials of respective prototypes are easy to be understood; [0043] 3) It saves resources of information system; [0044] 4) It shorten time for searching material modules (prototypes only need to be exploded once, no necessary to search various prototypes one-by-one); [0045] 5) It is no necessary to have duplicated storage so as to save memory space. [0046] The invention in the form of the no demand trial run module material on hand checking method is disclosed herein. These and other variations, which will be understood by those skilled in the art, are intended to be within the scope of the invention as claimed below. As previously stated, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms.

A material on hand checking method of trial-run prototypes/modules aims at resolving the problem of not able to forecast material shortage of trial-run prototypes/modules in electronic format by enterprises. Through the calculation method, when there is a request of trial-producing (trial-running), the Enterprise Resource Planning (ERP) server is capable of controlling and managing the inventory system, estimating required materials of trial-run prototype/module based on certain steps and procedures, and opening a new trial-run production line for productions. Enterprises can, therefore, decrease overstock in the facilities, reduce the risk of material purchasing and increase profit margins.

RELATED APPLICATIONS [0001] This application claims priority from the commonly-assigned U.S. provisional patent application Serial No. 60/637,659, filed on Dec. 21, 2004, the contents of which are incorporated here by reference. [0002] This application is also related to the following co-pending commonly-assigned patent application Ser. No. 10/293,943 of Sloate et al. entitled, “MULTIPLEXED SECURE VIDEO GAME PLAY DISTRIBUTION.” TECHNICAL FIELD [0003] The technology described relates to testing prototype software, and more particularly, to secure electronic delivery and evaluation of prototype software distributed over a network to third parties. One non-limiting example application is to testing and evaluating prototype game software. BACKGROUND [0004] Traditionally, software is used on “local” hardware. Consider video game software. A video game is typically purchased for use with a home video game system such as the Nintendo GameCube system or a home personal computer (PC). Home is a general term used as a contrast to playing a game at an arcade. To play a game, the user usually selects a video game on optical disk or other storage device and then controls the “local” hardware to begin executing the game. The game is then displayed on the user's television set, personal computer display, or a handheld computer display. But there are instances where software needs to be used on “remote” hardware. One such instance may occur during the software development. [0005] Before software is provided in its final form to end-users, it goes through a development, testing, and evaluation process. As the software moves through various stages of the process, it is oftentimes desirable to send that software to parties other than the developers to execute and experience (hereafter “third parties”). Those third parties, which may be part of the software development organization or outside of it, then test and/or evaluate the software. They often make suggestions to the software developers and/or marketers to help improve the software's performance and/or appeal. Although it is possible to bring such third parties to the physical plant of the software developer and carefully control the conditions under which third parties evaluate the prototype software, it may be more convenient and efficient to have third parties test prototype software away from the developer's physical plant. [0006] But testing outside the developer's physical plant raises security issues regarding the software. Most important is how to prevent illegal copying when the software is distributed electronically, when it is being tested, and when testing is complete. One security approach is to load the prototype software into a secure “lock box,” and have a developer employee physically deliver the prototype software to the third party evaluator. The delivery person must monitor its use, and when the third party evaluator is done, make sure that no copies were made and that the lock box copy is securely returned to the software developer. The time and expense associated with this approach are significant. Moreover, there is always a risk that the prototype software may be lost, stolen, or otherwise misappropriated despite precautions and preventive efforts. SUMMARY [0007] The technology described below overcomes these problems. The technology securely delivers software over a network to an evaluation site and monitors the evaluation of the software at the delivered site also via the network. In one example application, the software is prototype software to be tested by a third party different from a developer of the prototype software. One example prototype software is game software. The software is encrypted using one or more levels of encryption (preferably at least two). The encrypted software is transmitted from a server over the network to a client at the evaluation site for execution of the software to permit the evaluation of the software. But before the software can be executed, the client is initially authenticated by the server over the network. If the authentication is positive, the server authorizes execution of the software at the client. The server monitors the evaluation during the execution of the software at the client and determines whether the evaluation should be halted. The monitoring by the server prevents unauthorized use of the prototype software at the client. [0008] If the evaluation is halted, the server prohibits execution of the software or access to the software at the client. For example, the server may, via its control of the software at the client via the network, erase the prototype software from the client machine. The server may also prevent transmission, copying, or modification of the software at the client. [0009] The server may halt the evaluation for other reasons. For example, the client may be given only a certain time period or window during which the evaluation may be conducted. The server starts a check out period associated with when the server transmitted the software over the network to the client, monitors the check out period, and prohibits further execution of the software or access to the software at the client when the check out period expires. [0010] The monitoring may include the server periodically prompting the client to provide the server with some information, If the client fails to provide the prompted information within a predetermined time period, then the server prohibits execution of the software or access to the software at the client. The initial authentication may include requiring the client to provide the server a correct log-in identifier and a correct password. [0011] The client electronically receives the software via the network. Assuming the software is encrypted on at least two encryption levels, the client decrypts the software at one of the encryption levels and stores the decrypted software. The client initially performs authentication over the network with the server. For example, the client may have to provide the server with a correct log-in identifier and a correct password. If the authentication is positive, the software is temporarily stored at the client machine. Preferably, the software is temporarily stored in a password-protected hard disk drive that renders contents stored on the hard disk drive inaccessible to the evaluator. If the authentication is positive, the client is also permitted to decrypt a first portion of the software at the other of the encryption levels and executes the first software portion to permit evaluation of the first software portion. After decrypting the first portion and before execution of the first software portion is completed, the client decrypts a second portion of the software at the other of the encryption levels and executing of the second software portion to permit evaluation of the first software portion. This on-the-fly decryption of the software to be next executed is advantageous both in terms of security and in terms of efficient software execution. [0012] During the decrypting and executing, the client receives over the network multiple prompts from the server. The client responds to the prompts to ensure continued execution and evaluation of the software at the client. Access to and execution of the software is controlled by the server. Control signals from the server over the network prevent unauthorized use of the prototype software at or by the evaluator including preventing transmission, copying, or modification of the prototype software. BRIEF DESCRIPTION OF THE FIGURES [0013] FIG. 1 is function block diagram illustrating one non-limiting example of a system for securely delivering and monitoring evaluation of prototype software over a network; [0014] FIG. 2 is a flowchart illustrating non-limiting example procedures for securely delivering and monitoring evaluation of prototype software over a network; [0015] FIG. 3 is function block diagram illustrating another non-limiting example of a system for securely delivering and monitoring evaluation of prototype software over a network; and [0016] FIG. 4 is function block diagram illustrating another non-limiting example of a system for securely delivering and monitoring evaluation of prototype game software over a network. DETAILED DESCRIPTION [0017] In the following description, for purposes of explanation and non-limitation, specific details are set forth, such as particular nodes, functional entities, techniques, protocols, standards, etc. in order to provide an understanding of the described technology. It will be apparent to one skilled in the art that other embodiments may be practiced apart from the specific details disclosed below. In other instances, detailed descriptions of well-known methods, devices, techniques, etc. are omitted so as not to obscure the description with unnecessary detail. Individual function blocks are shown in the figures. Those skilled in the art will appreciate that the functions of those blocks may be implemented using individual hardware circuits, using software programs and data in conjunction with a suitably programmed microprocessor or general purpose computer, using applications specific integrated circuitry (ASIC), field programmable gate arrays, one or more digital signal processors (DSPs), etc. [0018] Reference is now made to FIG. 1 which illustrates an example software (SW) evaluation system 10 which includes a software (SW) developer facility or location 12 coupled to a software (SW) evaluator facility or location 16 via a network 14 (or some other electronic communications medium). The software developer facility 12 and the software evaluator facility 16 may or may not be within the control of the software developer. In other words, the software client 20 may be an in-house evaluator and the network 14 may be a private local area network (LAN). The term client includes a machine, a software entity or program, etc. On the other hand, the software evaluator might not be under the control of the software developer 12 . In that case, the network 14 might be a public communications network such as the Internet. [0019] The software developer facility 12 includes a software server computer 18 that includes a data processor 22 , a memory 24 , a display 26 , and a user interface 28 . The memory 24 stores prototype software 30 to be evaluated and a server application 31 for remote testing of prototype software including an encryption routine 32 , an authentication routine 34 , and a monitoring routine 36 . [0020] The encryption routine may include one or more proprietary and/or publicly known encryption algorithms. In a preferred example embodiment, the prototype software 30 is distributed over the network in a multi-level encrypted format. For example, the software 30 may be encrypted with a first encryption layer and a second encryption layer. The second encryption layer is used for added protection while the software is electronically distributed over the network 14 . Each encryption layer preferably uses different encryption algorithms, although the same encryption algorithm could be used but with different parameters at each layer, e.g., different encryption keys, passwords, etc. [0021] Once the prototype software has been successfully transferred to the remote software facility 16 , the second encryption layer may be removed by the software client 20 leaving the first encryption to protect the software program during storage at the client. Multiple encryption layers ensures a very high level of security for the prototype software when it is most likely to be intercepted by an unauthorized party during network transmission. Once physically temporarily stored at the third party station, the prototype software is less prone to rogue attack. Removing one or more extra encryption layers before storage permits faster execution of that prototype software at the third party client. By removing one encryption layer before storage, the prototype software can be executed more quickly, and as a result, tested more efficiently. The second encryption level could be, for example, public-private key cryptography with the SW server and client processors being provided with the necessary keys. Consequently, the software remains encrypted even after arrival and temporary storage at the client 20 to protect it against attack while stored at the client 20 . Greater security may be provided by adding further encryption levels, if desired. [0022] The authentication routine 34 authenticates a software client user (the software evaluator) and performs log-in identification, password verification, and then an on-going authentication dialog between the software server 18 and the software client 20 . The initial authentication must be successfully completed in order for the software to be temporarily stored by or at the client machine. If that authentication dialog is broken prematurely or is not conducted in accordance with the authentication protocol, the monitoring routine 36 in the server application 31 prevents the client application 52 from executing the prototype software. To resume execution, the user must perform some type of re-authorization process, e.g., repeat the log-in authentication procedure. [0023] The software client 20 includes a processor 40 , display 42 , a user interface 44 , and a memory 46 for storing the electronically-transferred prototype software 30 , preferably in encrypted format at 48 . In a preferred example embodiment, the processor 40 employs a decryption routine 50 to remove a top level of encryption before storing the software 38 in the memory 46 . The client application 52 includes an authentication routine 54 for communicating using the required protocol with the server's authentication routine 34 . The client application 52 also includes a remote access control routine 56 which gives the server application 31 remote control over the client 20 for the testing process until the client 20 no longer can access the prototype software. This control ensures only authorized users test the prototype software and only authorized use is made of the prototype software. The remote control prevents unauthorized use such as copying, modifying, or electronically distributing prototype software. [0024] Once the software client 20 has properly logged on and been authenticated by the server application 31 , the server application 31 enables the client processor 40 , via the remote access routine 56 , to access the prototype software 48 stored in the memory 46 . Assuming the prototype software 48 is stored in decrypted form, the client is provided by the processor 40 with the appropriate decryption tools to decrypt the prototype software for execution on-the-fly. On-the-fly decryption is preferred because it provides an extra level of security where only the specific software needed for immediate execution is available, while the remainder of the prototype software remains encrypted. On-the-fly decryption is also advantageous because the tester does not need to wait for the longer time that it takes for the entire prototype software to be decrypted. Alternatively, a hardware board or other device may be provided to the SW evaluator 16 and coupled to the client machine so as to perform the decryption. The SW evaluator 16 then is free to execute the prototype software for testing and evaluation. [0025] The security monitoring routine 36 at the SW developer facility 12 establishes a testing time period during which the SW client 20 is authorized to evaluate the prototype software. Once that time has expired, the security monitoring routine 36 halts further execution of the prototype software at the SW client 20 and erases that software from the memory 46 via the remote access control routine. The security monitoring routine 36 may perform other operations like searching the client memory 46 for unauthorized files and either erasing them or notifying the software developer. [0026] Reference is now made to the flow chart diagram in FIG. 2 illustrating example procedures for carrying out a method in accordance with one illustrative embodiment. Initially, an authorized person at the software developer facility 12 identifies prototype software to be tested along with the testing or evaluating entity, and obtains approval before distributing the prototype software for evaluation or other testing (step S 2 ). The prototype software, if not already encrypted, is encrypted using one or more layers of proprietary and/or public encryption algorithms (preferably multiple layers) (step S 4 ). The encrypted software is then sent electronically, e.g., over some sort of network, to a client where the encrypted software is stored in memory 48 . While the client could be run on a common personal computer (PC) or the like, the client may also be implemented using a special testing machine to increase security. After removing at least a first encryption layer in the preferred embodiment, the stored prototype software may, in some implementations such as those described later, be password protected to further prevent unauthorized copying. A “check-out” time period is started by the monitoring routine 36 (step S 6 ). The third party evaluator interacts with the software client 20 via the display and user interface to log-in with the software server via the network using, for example, a log-in ID and a log-in password (step S 8 ). The server application 18 authenticates the evaluator, and instructs the client processor 40 to decrypt on-the-fly the encrypted prototype software being retrieved from memory 48 and then execute the prototype software (step S 10 ). [0027] As the prototype software is executed on the software client, an authentication dialog is maintained between the server and the client. If that dialog is broken or is otherwise improper, the server disables the client from further execution of the prototype software (step S 12 ). Once the check out period expires, the server erases the prototype software from the client memory and disables any further execution of that prototype software at the client (step S 14 ). [0028] FIG. 3 illustrates another non-limiting example software evaluation system similar to that shown in FIG. 1 . But in this embodiment, the client works in conjunction with a software execution engine 54 that includes hardware and/or software 56 that is specifically configured to execute the prototype software. The software execution engine 54 also includes a memory 58 (such as a hard disk drive) to store the prototype software (preferably encrypted) received via the network 14 and the client 20 from the software server 18 . The software execution engine 54 may be integrated with the client machine 20 or may be coupled to the client machine 20 . Such an execution engine 54 may be necessary or useful for specialized or otherwise proprietary prototype software execution. Moreover, the software execution engine 54 permits additional security. For example, if memory 58 is a hard drive, it may be password protected using an advanced technology attachment (ATA)-based password. Such password protection is typically not readily implemented for the hard drive of the client 20 . [0029] In this example embodiment, the client 20 stores the client application 48 , which includes an authentication routine 50 , to perform log-on and then handshake communications with the server authentication routine 34 during the time when the prototype software is being executed by the software evaluator. In addition, the client application 48 includes a remote access control routine 52 that permits the monitoring routine 56 in the software server 18 to control the client machine 20 at least with respect to its handling of the prototype software. Once the test period expires or there has been some other event, the monitoring routine 36 erases the prototype software from the memory 58 via the remote access control routine 52 . [0030] FIG. 4 shows another example non-limiting embodiment applied to video games. A video game developer facility 60 includes a game server 68 coupled via the Internet 62 to a game evaluator facility or location 64 . Access to the Internet by the server 68 and the client 92 may be for example, by way of respective virtual private network (VPN) adaptor 90 . The game evaluator facility 64 is coupled via a USB link to a game execution engine 66 . The game server 68 includes a processor 70 , a display 72 , a user interface 74 , and a memory 76 . The memory 76 includes prototype game software 78 to be evaluated by the game evaluator. The memory 76 also includes a server application 80 with an encryption routine 81 , an authentication routine 82 , and a monitoring routine 88 . [0031] The client 92 includes a processor 94 , a client application 95 which includes an authentication routine 96 and a remote access control routine 97 , a display, a user interface, coupled to a game controller 102 . The game execution engine 66 includes game-specific execution hardware and/or software 104 . One non-limiting example of a specialized game execution engine might include hardware and software from a Nintendo GameCube entertainment system that readily supports play of prototype video games being designed for Nintendo's GameBoy Player. [0032] The hard disk drive (HDD) 106 stores the downloaded prototype software received from the client 92 in an encrypted format. The game-specific execution hardware and/or software 104 is able to decrypt the prototype game software on-the-fly during game play. As in FIG. 3 , the hard disk 106 is protected by a password based on ATA security which renders the hard drive inaccessible outside of the system shown in FIG. 4 . [0033] The above technology provides substantial advantages for testing and evaluating software. The software may be provided cheaply and securely by any suitable electronic means. There is no need for humans to deliver, monitor, and retrieve the software at remote test sites. Control of the software is maintained throughout the delivery, test, and evaluation process by the software developer. Various security features ensure that the software is not compromised or copied during any part of that process. [0034] Although various embodiments have been shown and described in detail, the claims are not limited to any particular embodiment or example. None of the above description should be read as implying that any particular element, step, range, or function is essential such that it must be included in the claims scope. The scope of patented subject matter is defined only by the claims. The extent of legal protection is defined by the words recited in the allowed claims and their equivalents. No claim is intended to invoke paragraph 6 of 35 U.S.C §112 unless the words “means for” are used.

Prototype software is securely delivered and evaluated by electronic transfer over a network. The software is secured by multiple levels of encryption to prevent unauthorized copying, modification, and/or use of the prototype software. Electronic transfer of the prototype software minimizes the time and cost associated with providing prototype software for testing to remote third party testers. Once the software has been transferred electronically to the third party tester, the software developer electronically maintains control of that software by restricting access to an authorized third party, monitoring testing, and deleting any files related to the prototype software from the third party test workstation.

RELATED APPLICATION This patent arises from an application claiming priority as a continuation of U.S. application Ser. No. 12/644,151, (Now U.S. Pat. No. 8,549,267), entitled “METHODS AND APPARATUS TO MANAGE PARTIAL-COMMIT CHECKPOINTS WITH FIXUP SUPPORT” which was filed on Dec. 22, 2009, granted on Oct. 1, 2013 and is hereby incorporated herein by reference in its entirety. TECHNICAL FIELD The present disclosure relates to speculative execution, and in particular, to methods and apparatus to manage partialcommit-checkpoints with fixup support. BACKGROUND In the context of microprocessors, a speculative execution system (SES) is a system that enables the speculative execution of instructions. Speculative execution is typically leveraged to enable safe execution of dynamically optimized code (e.g., execution of optimized regions of code in a hardware (HW) and/or software (SW) co-designed systems). The data produced by the speculative execution of instructions is typically referred to as speculative data. To ensure correct execution, the system may protect the current architectural state (e.g., the state visible by the user) by keeping it unmodified during the speculative execution of instructions. If the speculative execution is incorrect, the SES discards the speculative data and makes one or more attempts to re-execute the instructions again. In some circumstances, additional attempts to re-execute the instructions occur by way of a more conservative approach (e.g., via a non-speculative execution of instructions, via a smaller degree of speculation in the execution, etc.). On the other hand, in the event that the speculative execution is proven correct, the SES may convert the speculative execution into a non-speculative execution, thereby changing the architectural state. This may be done by promoting the speculative data to non-speculative data. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1, 2 and 3 are block diagrams of example platforms that may be used by the methods and apparatus described herein to generate partial commit-checkpoints. FIGS. 4, 5, 6, 7 and 8 are example code blocks that may be executed in connection with the example platforms of FIGS. 1-3 . FIG. 9 is a block diagram of an example fixup code circuit that may be used by the example platforms of FIGS. 1-3 . FIGS. 10-12 are example processes that may be carried out using instructions stored on tangible machine readable media to implement the example fixup code circuit of FIGS. 1-3 and 9 . FIG. 13 is a schematic diagram of an example processor platform that may execute the example processes of FIGS. 10-12 and/or the example fixup code circuit of FIGS. 1-3 and 9 . DETAILED DESCRIPTION As described in further detail below, the methods and apparatus described herein may be implemented under the assumption that a processor that employs a speculative execution system (SES) may either perform speculative execution (S) of instructions (I), and/or non-speculative execution (N) of instructions (I). Additionally, the example SES may perform a Checkpoint (K) before any speculative execution (S) of instructions. The example Checkpoint ensures that the architectural state of the processor is protected from speculative execution until the SES performs a Commit (C). After the Checkpoint, the processor (e.g., a microprocessor) can speculatively execute any number of instructions. If the speculative execution of the instructions is proven correct, the SES may perform a Commit (C), which may modify the architectural state of the processor with the data computed by the speculative execution. If the speculative execution is incorrect, the SES may perform a Recovery (R) by discarding the speculative data and rolling the execution back to the last Checkpoint performed. After a Commit or a Recovery, the example SES may either start a non-speculative execution of instructions (N) or perform a new Checkpoint and continue speculatively executing other instructions (S). A speculative execution (S) of instructions is usually limited to instances between a Checkpoint (K) and a Commit (C) or, in some instances between a Checkpoint (K) and a Recovery (R). The dynamic region of code composed by all the instructions speculatively executed between a Checkpoint (K) and a Commit (C) and/or between a Checkpoint (K) and a Recovery (R) may be considered a dynamic atomic region. Additionally, Recovery and Commit operations may be either conditionally coded inside an atomic region (e.g., assert), or dynamically injected by HW when unexpected speculative results are detected (e.g., exception). As used herein, the term “atomic region” refers to instances in which all the speculative data is turned into non-speculative data by the Commit operation (C), and/or all the speculative data is discarded by the Recovery (R) operation. Dynamic execution of code by an example processor may occur in any number of execution sequences (E). In the illustrated examples of Equations 1 through 3, I refers to zero or more static instructions in a static program, K refers to a dynamic Checkpoint operation performed by an SES execution, C refers to a dynamic Commit operation performed by an SES execution, R refers to a dynamic Recovery operation performed by an SES execution, S refers to a speculative execution of zero or more static instructions (I), and N refers to a non-speculative execution of zero or more static instructions (I). E 1 = KSCKSCKSRNKSC . Equation ⁢ ⁢ 1 E 2 = KSC ︷ Atomic ⁢ ⁢ Execution ⁢ ⁢ N ︸ Non ⁢ - ⁢ Spec ⁢ ⁢ Execution ⁢ ⁢ KSR ︷ Atomic ⁢ ⁢ Execution ⁢ ⁢ KSC ︸ Atomic ⁢ ⁢ Execution . Equation ⁢ ⁢ 2 E 3 = KSC ︸ Atomic ⁢ ⁢ Execution ⁢ KSC ︷ Atomic ⁢ ⁢ Execution ⁢ KSR ︸ Atomic ⁢ ⁢ Execution ⁢ N ⁢ ⁢ KSC ︷ Atomic ⁢ ⁢ Execution ⁢ N ⁢ ⁢ KSC ︸ Atomic ⁢ ⁢ Execution . Equation ⁢ ⁢ 3 In some example SESs, execution is optimized by way of employing an operation that performs a Commit (C) and a Checkpoint (K) in a single operation, which may be referred-to as a “Commit-Checkpoint” (C k ). An example Commit-Checkpoint (C k ) may execute Commit (C) and then a Checkpoint (K) during execution of back-to-back atomic regions. Example Equation 4 below illustrates an example Commit-Checkpoint (C k ) derived from Equation 3 above. E 4 = KSC k ⁢ SC k ⁢ SR ⁢ ︷ Back ⁢ ⁢ to ⁢ ⁢ back ⁢ ⁢ atomic ⁢ ⁢ execution ⁢ ⁢ of ⁢ ⁢ 3 ⁢ ⁢ regions ⁢ N ⁢ ⁢ KSC ︸ Atomic ⁢ ⁢ Execution ⁢ N ⁢ ⁢ KSC ︷ Atomic ⁢ ⁢ Execution . Equation ⁢ ⁢ 4 The example Commit-Checkpoint (C k ) operations typically save a precise architectural state so that, in the event of a failure of a Speculative execution (S), the example SES may recover the state back to a point in which the Commit-Checkpoint (C k ) was performed. The point at which the Commit-Checkpoint (C k ) was performed is considered a safe state and allows regular execution to be reattempted. Any such reattempt at execution is typically performed in a more conservative manner, such as by way of non-speculative execution of instructions (N), as shown in example Equation 5 below. E 5 =K 1 S 1 C K2 S 2 C K3 S 3 C K4 S 4 R 4 N 4 K 5 S 5 C K6 S 6 C K7   Equation 5. In the illustrated example of Equation 5, execution five (E 5 ) includes a Commit-Checkpoint (C k4 ) that commits speculative results of S 3 and saves a precise architectural state. Thereafter, the example SES performs a Recovery operation (R 4 ) to recover a precise architectural state saved at C k4 . As described above, in response to one or more failures of speculative execution, some SESs proceed by executing code in a more conservative manner, such as the example Non-Speculative operation (N 4 ) shown above. In the event that a processor requires a precise architectural state when performing a Commit-Checkpoint operation, dead code and/or partially dead code may not be optimized across the atomic region(s). Generally speaking, partially dead instructions include those that produce a value that may not be used by subsequent computations. Instructions that define architectural values that are not used by code in subsequent atomic regions are partially dead because they still might be needed by exception and/or interruption handlers executed between one or more atomic region(s). For example, in the illustrated example of Equation 5, operations in S 3 that compute architectural values that are overwritten by operations in S 4 cannot be eliminated because C k4 requires a precise architectural state when saving the state. The state saved in the illustrated example must also include the state computed by S 3 and overwritten by S 4 . The methods and apparatus described herein allow, in part, replacing a Checkpoint (C ki ) by a partial commit-checkpoint P i (fu i ) operation that saves only a portion (e.g., a non-precise architectural state) of the architectural state of the processor. As such, one or more optimizations may be performed with one or more atomic regions when dead code and/or partially dead code are identified. The example partial commit-checkpoint P i (fu i ) is associated with fixup code fu i . In operation, if execution rolls back to the example partial commit-checkpoint P i (fu i ) and the processor requires a full (precise) architectural state, then the example SES executes the fixup code fu i to recover the full architectural state. Checkpoints are created prior to speculative execution so that the prior CPU state may be recovered in the event that a speculation was incorrect. Once the CPU state has been recovered, then execution may resume by executing a more conservative version of the code (e.g., a non-speculative version of code). Creating checkpoints includes saving register values to a storage (e.g., a memory) location representative of the state of the CPU before attempting to execute a speculative path. In some instances, register values to be saved to the storage location may require instruction calculation(s) to derive the register values. As such, creating checkpoints consumes both storage resources and CPU processing resources. In the event that the speculation was correct, the checkpoint information is no longer needed. Generally speaking, checkpointing result in two storage locations, one containing a speculative CPU state (e.g., speculative storage), and one containing a non-speculative CPU state (e.g., checkpoint storage) that can be restored in the event of an exception. Any register states stored in the non-speculative storage may be discarded in favor of using the speculative storage register states when speculation is correct. The example SES may perform a Commit operation to transfer the data from the speculative storage to the non-speculative storage. Typically, a Commit operation requires the architectural state to be precise, which prevents the SES from removing computed values in the precise state that may never be used in subsequent computations. In other words, when speculation is correct/successful, some CPU resources that are consumed to generate the full precise state may be wasted and/or result in work performed by the CPU that is never utilized. The methods and apparatus described herein employ, in part, partial commit-checkpoint operations to relax the precise architectural state constraints and enable more aggressive dynamic optimizations (e.g., across dynamic atomic regions). For example, the methods and apparatus described herein generate fixup code that may be executed only when necessary (e.g., after an exception occurs) rather than explicitly calculating a register state before storing to the non-speculative storage location(s). As a result, rather than consuming CPU cycles to calculate a precise register state prior to storage in the non-speculative storage location(s), an address of the generated fixup code, which is known a priori may be stored instead, thereby reducing CPU cycle consumption during the speculative execution process. FIG. 1 is a schematic illustration of an example platform 100 that may be used with the methods and apparatus described herein. In the illustrated example of FIG. 1 , the platform 100 includes a CPU 102 , a speculative execution system (SES) 103 , a memory 104 , a basic input/output system (BIOS) 106 , one or more input/output (I/O) device(s) 108 , hard disk drive (HDD) and/or optical storage 110 , a dynamic optimizer module (OPT) 112 , and a fixup module 114 . The example fixup module 114 may include the OPT 112 and the SES 103 , but is not limited as such. Additionally, the example SES 103 includes an example Checkpoint (K) logic module 120 , a Commit (C) logic module 122 , a Commit-Checkpoint (C k ) logic module 124 , and a recovery logic module 126 . Without limitation, the example platform 100 may include any number and/or type of elements other than those shown in FIG. 1 . In operation, the example CPU 102 executes code retrieved from the example memory 104 , the example BIOS 106 , the example I/O 108 (including sources external to the example platform 100 such as, but not limited to an intranet, the Internet, etc.), and/or the example HDD 110 . During code execution, the SES 103 may execute one or more dynamically optimized code regions, thereby minimizing instances of CPU stall. To ensure correctness, the example SES 103 may Checkpoint (e.g., via the example Checkpoint (K) logic module 120 ) the architectural state of the example CPU 102 , execute the optimized code, and Commit (e.g., via the example Commit (C) logic module 122 ) the speculative results after the execution is proven correct. However, in the event that the execution is incorrect (e.g., due to one or more exception(s)), the example SES 103 rolls the execution back by recovering the checkpoint (e.g., via the example Recovery logic module 126 ) and restarting execution with a more conservative (e.g., less speculative) execution. When the example OPT 112 identifies a region of code for optimization, the OPT 112 may analyze an instruction from the region to determine if it is a candidate instruction for fixup code. As described in further detail below, fixup code includes, but is not limited to pointers to executable instructions and/or executable instructions stored in a memory for later execution, if necessary. If candidate instructions for fixup code are found, the example OPT 112 generates a partial commit-checkpoint, generates fixup code, and the example fixup module 114 associates the address of the fixup code with the partial commit-checkpoint operation. In effect, the partial commit-checkpoint operation of the fixup module 114 enables the example platform 100 to perform a checkpoint operation without requiring a precise architectural state of the CPU 102 . In the event that the CPU precise architectural state needs to be restored (e.g., due to an exception), the example SES 103 references the address of the generated fixup code to calculate the precise register value corresponding to the optimized instruction(s). In other words, CPU resources directed to calculating the precise register value do not need to occur until after the exception condition is proven to be true. At least one benefit realized in view of the example partial commit-checkpoint operation implemented by the example fixup module 114 is a reduction in CPU resources that are otherwise consumed by executing all instructions associated with register value calculation(s). For instances where speculation is correct, the quantity and/or CPU burden is reduced by avoiding one or more calculations of all CPU register values. On the other hand, for instances where speculation is incorrect, the methods and apparatus described herein facilitate a mechanism to calculate a precise register state. While the illustrated example of FIG. 1 includes the OPT 112 and the fixup module 114 within the example platform 100 , the methods and apparatus described herein are not limited thereto. For example, the example SES 103 , OPT 112 and/or the example fixup module 114 may be located externally to the example platform, as shown in FIG. 2 . Alternatively, the example OPT 112 and/or the example fixup module 114 may be located external to the example CPU 102 as software and/or hardware, as shown in FIG. 3 . One or more descriptions of the methods and apparatus described herein will generally reference the example platform 100 as shown in FIG. 1 , but such descriptions are for purposes of illustration and not limitation. FIGS. 4 and 5 illustrate two examples that employ commit-checkpoint operations ( 400 , 500 ), the first of which (i.e., FIG. 4 ) may be employed by the CPU 102 to commit a speculative state generated by region A and create a traditional checkpoint, and the second of which (e.g., FIG. 5 ) is an example operation in view of the methods and apparatus described herein. In the illustrated example of FIG. 4 , a first atomic region A includes four instructions (i 1 , i 2 , i 3 , and i 4 ) and a second atomic region B includes two instructions (i 5 and i 6 ). FIG. 4 illustrates an example control flow graph (CFG), in which Atomic regions A and B may each be referred to as a node and paths of execution between nodes may be referred to as an edge (represented by an arrow). During one or more optimization processes executed by, for example, the OPT 112 of the CPU 102 , instructions may be analyzed to identify partially dead code (also referred to as partially dead instructions). As described herein, the example SES 103 includes a system that provides support for checkpoint, commit and/or recovery operations to enable speculative execution, but the example SES 103 is not limited thereto. Additionally, as described herein and in further detail below, the example OPT 112 facilitates, in part, dynamic optimization(s) and/or fixup code generation. In the event that a full precise architecture state is deemed necessary, the example SES 103 may invoke the fixup code after a Recovery operation(s). As described above, partially dead instructions are instructions that produce a value that may not be used by subsequent computation. Instructions that define architectural values that are not used by code in subsequent atomic regions are partially dead because they may still be needed by exception and/or interruption handlers executed between atomic regions. In the illustrated example of FIG. 4 , register R 1 is initially zero ( 402 ) and register R 2 is initially populated with a value of two ( 404 ) when entering atomic region A. Example instruction i 1 calculates a value for register R 1 as the existing value of register R 1 plus the integer two. Example instruction i 2 uses the calculated value of R 1 in its calculation to derive a value for register R 3 . Additionally, example instruction i 2 calculates a value for register R 3 , which uses the previously calculated value R 1 . Example instruction i 3 calculates a value for register R 4 that also uses the previously calculated value R 1 . Finally, example instruction i 4 in atomic region A calculates a value for R 2 , which uses value R 2 itself divided by the previously calculated value R 1 . Of the four example instructions i 1 , i 2 , i 3 and i 4 of atomic region A, only instructions i 2 and i 3 are considered partially dead code because their result has no further effect on either any other instruction within atomic region A or any subsequent atomic region(s). That is, the results computed by i 2 and i 3 cannot be used by computations executed after region B because region B overwrites the computed results when executing instruction i 5 and i 6 , but they may be required in the event that an exception and/or interruption is handled between regions A and B. In other words, if no extraordinary events (such as an interruption and/or exception) happen after region A commits and before region B commits, then instructions i 2 and i 3 are not required because their results will not be used. Nonetheless, in case of extraordinary events (e.g., exceptions), the CPUs have to provide a precise architectural state to an exception handler. This is usually realized by requiring that checkpoints reflect absolute state precision. In this example, each of instructions i 1 , i 2 , i 3 and i 4 are calculated to allow the precise values for R 1 , R 2 , R 3 and R 4 to be saved by the Commit-Checkpoint operation at i 4 . Checkpoint storage 406 shows the architectural state after the C k operation at i 4 . The end of an atomic region, such as the example atomic region A of FIG. 4 , may be terminated with a commit-checkpoint instruction (C k ) 408 , which is a representation of the end of an atomic region and the beginning of a new atomic region, and causes the CPU 102 to commit the speculative execution of the executed atomic region and record a new checkpoint to enable the speculative execution of the next region. Generally speaking, whenever a commit is performed, the effects of the instructions in the atomic region become visible to other devices (e.g., other processors), and corresponding effects (e.g., register updates, memory stores, etc.) are made permanent. Although commit marks are described herein, the methods and apparatus described herein are not limited thereto and may be applied to other atomic regions and/or commit models without limitation. Atomic region B represents a branch from atomic region A. In the illustrated example of FIG. 4 , atomic region B includes instruction i 5 to calculate a value for register R 4 and instruction i 6 to calculate an instruction for R 3 . As an exception may occur at any point of execution, providing a mechanism to commit-checkpoint with full precision facilitates, in part, an ability to recover in a safe manner. Additionally, the commit-checkpoint consumes CPU cycles by requiring calculation(s) for each register within any affected atomic region(s). The methods and apparatus described herein facilitate, in part, providing for full precision checkpointing and reducing CPU resource consumption during one or more checkpointing operation(s). The example atomic regions A and B and instructions i 1 , i 2 , i 3 , i 4 , i 5 and i 6 of FIG. 5 are substantially similar to the atomic regions and instructions in FIG. 4 . However, unlike the example of FIG. 4 , where the precise architectural state 406 is saved by the C k operation 408 , the illustrated example of FIG. 5 includes a partial commit-checkpoint 516 that saves part of the architectural state 512 and includes associated fixup code 514 that can be executed to recover the full (precise) architectural state in case it is needed. Instructions i 2 and i 3 in atomic region A of FIG. 5 are shown crossed-out as an indication of code that was removed by the example OPT 112 , thereby improving the execution by avoiding additional CPU cycles toward calculation of instructions i 2 and i 3 . However, to allow the recovery of the precise architectural state in the event of an exception occurring in atomic region B and/or anywhere between regions A and B, the fixup code 514 is created. The example partial commit-checkpoint instruction 516 causes the address(es) of the fixup code (fu_add) to be associated with the partial commit-checkpoint. In operation, the example partial commit-checkpoint operation 500 generates a non-precise checkpoint 510 by eliminating the computation of instructions i 2 and i 3 . The instructions associated with i 2 and i 3 may be copied from the atomic region A to the example fixup code 514 during the dynamic optimization. Unlike the identified partially dead instructions i 2 and i 3 , any remaining instructions are executed (i 1 and i 4 ) and their speculatively calculated values 514 are committed and saved by the partial commit-checkpoint at i 4 . As a result, CPU instructions that would have been consumed to calculate register values R 3 and R 4 are avoided, thereby improving a CPU utilization metric during region A execution. In other examples, an atomic region may execute over any number of iterations and/or in a loop. In the illustrated example of FIG. 6 , atomic region A includes instructions i 1 , i 2 , i 3 , i 4 and i 5 , and atomic region B includes instruction i 6 . While instruction i 4 calculates register value R 4 during each loop iteration, register R 4 is not used again in atomic region A and the computation represents wasted CPU cycles. The illustrated example of FIG. 7 shows how to improve the regions of FIG. 6 by, in part, removing instruction i 4 (see cross-out) and moving it to atomic region B, which does require register value R 4 when computing instruction i 6 . In this example, the value of register R 4 is only computed after leaving the loop, which may reduce the number of times that i 4 is executed. Although removal of instruction i 4 successfully saves CPU cycles from being consumed, such removal results in the commit-checkpoint operation of region A to save a processor state that lacks precision. In this example, if the state needs to be recovered to this checkpoint, the architectural state will not be precise. To allow the precise architectural state to be reconstructed when recovering the state saved by the partial commit-checkpoint, the methods and apparatus described herein permit fixup code to be generated for the removed instruction i 4 from atomic region A. As a result, when an exception occurs, a precise state of the CPU may be re-constructed during the recovery operation. For example, FIG. 8 illustrates fixup code 802 associated with fixup label fu 1 804 . The fixup code 802 represents instruction i 4 so that, in the event of recovery to the partial commit-checkpoint performed at i 5 in atomic region A, the precise state of register R 4 can be recovered. In case a recovery happens and the precise state is required, the example SES 103 can execute the associated fixup code 802 and reconstruct the full precise state. FIG. 9 is a schematic illustration of the example fixup module 114 , OPT module 102 and SES 103 of FIG. 1 . In the illustrated example of FIG. 9 , the fixup module 114 includes a fixup code generator 906 , a fixup code memory 912 , a fixup code fetch module 920 and a partial Commit-Checkpoint P(fu) logic module 918 . As described above in connection with FIG. 1 , the example SES 103 includes the Checkpoint (K) logic module 120 , the Commit (C) logic module 122 , the Commit-Checkpoint (C k ) logic module 124 and the recovery logic module 126 , and the example OPT 112 includes a dynamic optimizer 914 . The example fixup module 114 facilitates generation of fixup code in response to one or more requests. Requests to generate fixup code may be generated by the example dynamic optimizer 914 in response to receiving one or more indications to optimize code in a speculative manner. The example fixup code generator 906 may associate an address associated with candidate code with a fixup code label. Fixup code generated by the fixup code generator 906 and associated label(s) may be stored in the example fixup code memory 912 . While the example fixup code memory 912 is shown as part of the example fixup module 114 , the example fixup code memory 912 may be located elsewhere, without limitation. In operation, the example fixup module 114 may employ the partial commit-checkpoint logic module 918 in the example fixup module 114 to invoke a partial commit-checkpoint, as described above. In response to a request to invoke the fixup code, the example fixup code fetch module 920 queries and/or otherwise retrieves fixup code from the fixup code memory 912 that was previously generated by the example fixup code generator 906 . To provide support for Checkpoint (K), Commit (C), Commit-Checkpoint (Ck) and/or recovery operations, the example SES 103 invokes one or more of the example Checkpoint (K) logic module 120 , the example Commit (C) logic module 122 , the example Commit-Checkpoint (Ck) logic module 124 and/or the example recovery logic module 126 . In operation, in response to one or more requests from the example SES 103 , the example fixup code fetch module 920 queries and/or otherwise acquires fixup code from the example fixup code memory 912 . While the example platform 100 and fixup module 114 of FIGS. 1-3 and 9 have been shown to create partial commit-checkpoints to improve checkpoint creation speed and efficiency, one or more of the elements and/or devices illustrated in FIGS. 1-3 and 9 may be combined, divided, re-arranged, omitted, eliminated and/or implemented in any other way. Further, the example CPU 102 , SES 103 , memory 104 , BIOS 104 , OPT 112 , fixup module 114 , fixup code generator 906 , fixup code memory 912 , dynamic optimizer 914 , partial commit-checkpoint logic module 918 and/or fixup code fetch module 920 of FIGS. 1-3 and 9 may be implemented by one or more circuit(s), application specific integrated circuit(s) (ASIC(s)), programmable logic device(s) (PLD(s)), and/or field programmable logic device(s) (FPLD(s)), etc. When any of the appended apparatus claims are read to cover a purely software and/or firmware implementation, at least one of the example CPU 102 , SES 103 , memory 104 , BIOS 104 , OPT 112 , fixup module 114 , fixup code generator 906 , fixup code memory 912 , dynamic optimizer 914 , partial commit-checkpoint logic module 918 and/or fixup code fetch module 920 of FIGS. 1-3 and 9 are hereby expressly defined to include a tangible medium such as a memory, DVD, CD, etc. storing the software and/or firmware. Further still, the example CPU 102 , SES 103 , memory 104 , BIOS 104 , OPT 112 , fixup module 114 , fixup code generator 906 , fixup code memory 912 , dynamic optimizer 914 , partial commit-checkpoint logic module 918 and/or fixup code fetch module 920 of FIGS. 1-3 and 9 may include one or more elements, processes and/or devices in addition to, or instead of, those illustrated in FIGS. 1-3 and 9 , and/or may include more than one of any or all of the illustrated elements, processes and devices. FIGS. 10-12 illustrate example processes that may be performed to implement the example SES 103 , OPT 112 and fixup 114 modules of FIGS. 1-3 and 9 . The example processes of FIGS. 10-12 may be carried out by a processor, a controller and/or any other suitable processing device. For instance, the example processes of FIGS. 10-12 may be embodied in coded instructions stored on any tangible computer-readable medium such as a flash memory, a CD, a DVD, a floppy disk, a read-only memory (ROM), a random-access memory (RAM), a programmable ROM (PROM), an electronically-programmable ROM (EPROM), and/or an electronically-erasable PROM (EEPROM), an optical storage disk, an optical storage device, magnetic storage disk, a magnetic storage device, and/or any other medium that can be used to carry or store program code and/or instructions in the form of machine-readable instructions or data structures, and that can be accessed by a processor, a general-purpose or special-purpose computer, or other machine with a processor (e.g., the example processor platform P 100 discussed below in connection with FIG. 13 ). Combinations of the above are also included within the scope of computer-readable media. Machine-readable instructions comprise, for example, instructions and/or data that cause a processor, a general-purpose computer, a special-purpose computer, or a special-purpose processing machine to implement one or more particular processes. Alternatively, some or all of the example processes of FIGS. 10-12 may be implemented using any combination(s) of ASIC(s), PLD(s), FPLD(s), discrete logic, hardware, firmware, etc. Also, one or more operations of the example processes of FIGS. 10-12 may instead be implemented manually or as any combination of any of the foregoing techniques, for example, any combination of firmware, software, discrete logic, and/or hardware. Further, many other methods of implementing the example operations of FIGS. 10-12 may be employed. For example, the order of execution of the blocks may be changed, and/or one or more of the blocks described may be changed, eliminated, sub-divided, or combined. Additionally, any or all of the example processes of FIGS. 10-12 may be carried out sequentially and/or carried out in parallel by, for example, separate processing threads, processors, devices, discrete logic, circuits, etc. The example processes of FIG. 10 include a checkpoint logic process 1000 , a commit logic process 1004 , a commit-checkpoint logic process 1008 , a partial commit-checkpoint logic process 1014 , and a recovery logic process 1022 . The example checkpoint logic process 1000 , which may be executed by the example checkpoint logic module 120 of FIGS. 1-3 and 9 , saves a current architectural state of a CPU (block 1002 ). The example commit logic process 1004 , which may be executed by the example commit logic module 122 of FIGS. 1-3 and 9 , commits any speculative data that may have been saved to a storage (e.g., a memory) during one or more speculation operation(s) (block 1006 ). The example commit-checkpoint logic process 1008 , which may be executed by the example commit-checkpoint logic module 124 of FIGS. 1-3 and 9 , commits any speculative data (block 1010 ), and then saves the currently architectural state of the CPU (block 1012 ). Unlike traditional speculation approaches, the example partial commit-checkpoint logic process 1014 , which may be executed by the example fixup module(s) 114 and/or the example partial commit-checkpoint 918 of FIG. 9 , commits any speculative data to a memory (block 1016 ) and saves an architectural state of the CPU (block 1018 ). Thereafter, the example process 1014 annotates the recently created checkpoint as a partial commit-checkpoint and associates it with fixup code (fu) (block 1020 ). The example fixup code (fu) may be created by the example fixup code generator 906 , as shown in FIG. 9 . During instances in which a recovery operation occurs (block 1022 ), which may be executed by the example recovery logic module 126 , any speculative data that was previously stored is discarded (block 1024 ). To allow further safe operation of the CPU, the state of the CPU at the checkpoint is loaded (block 1026 ) and the example fixup code fetch module 920 determines whether the previously saved state is also a partial commit-checkpoint (block 1028 ). If not, then control advances in a traditional manner, otherwise the fixup code fetch module 920 invokes any fixup code (fu) associated with the partial commit-checkpoint (block 1030 ) to obtain full precision. FIG. 11 illustrates an example process 1100 of CPU execution in view of the methods and apparatus described herein. If no checkpoint operation occurs (block 1102 ), then instructions are executed in a non-speculative manner (block 1104 ). On the other hand, in the event of a checkpoint operation (block 1102 ), checkpoint logic may be executed (block 1106 ) and one or more instructions may be executed in a speculative manner (block 1108 ). In the event of an exception (block 1110 ), the example recovery logic module 126 may initiate a recovery of the architectural state (block 1112 ) and handle the exception (block 1114 ), as described in the example process 1022 of FIG. 10 . On the other hand, if there is no exception (block 1110 ), the example SES 103 determines if a checkpoint operation of type commit-checkpoint (C k ) was to be executed (block 1116 ). If so, then the example commit-checkpoint logic module 124 may execute commit-checkpoint logic (block 1118 ), such as by way of the example process 1008 of FIG. 10 . If the example SES 103 determines that a checkpoint of type partial commit-checkpoint was to be executed (block 1120 ), then the example partial commit-checkpoint logic module 918 may execute partial commit-checkpoint logic (block 1122 ), such as by way of the example process 1014 of FIG. 10 . In the event that the example SES 103 determines the occurrence of a commit operation (block 1124 ), then the example commit logic module 124 may execute the example process 1004 of FIG. 10 (block 1126 ). In case none of the previous operations are detected, the SES 103 may proceed by speculatively executing more instructions (block 1108 ). The methods and apparatus described herein also improve one or more optimization techniques (e.g., partial dead code elimination (PDE)) that may be employed by processors and/or platforms. Generation of fixup code and analysis of executable code, such as analysis of one or more control flow graphs (CFGs), may be realized by the example OPT 112 . Traditional optimization techniques typically evaluate a single atomic region node at a time, but cannot perform one or more evaluative optimizations across multiple nodes. To facilitate, in part, optimization across regions (nodes), the example dynamic optimizer 914 analyzes a CFG node for instances of a checkpoint operation, such as a commit-checkpoint operation (C k ). In response to detecting the checkpoint operation, the example dynamic optimizer 914 generates a placeholder block and connects the block that contains the checkpoint operation to the placeholder block by using a control flow edge before moving on to another CFG node, if any. When any number of CFG nodes have been analyzed to detect instances of a checkpoint operation, the example dynamic optimizer 914 proceeds with the optimization. During optimization, the example dynamic optimizer 914 may identify partially dead code candidates and move code from one node to another node to optimize one or more paths (edges). For example, a generated node may be an atomic region or one of the placeholder blocks inserted previously by the example dynamic optimizer 914 . When the optimization is complete, the example OPT 112 invokes the example dynamic optimizer 914 to identify which placeholder blocks are still empty (e.g., the optimization technique employed did not identify any changes to further optimization), and which placeholder blocks are populated with code after the optimization. Empty placeholder blocks may be removed because, in part, they have no further use for the optimization. However, placeholder blocks that are not empty are indicative of an architectural state that is no longer precise in response to a checkpoint operation (e.g., C k ). The non-empty placeholder blocks contain instructions that, when executed, fix and/or otherwise ensure a precise architectural state associated with the checkpoint operation. In this sense, the example dynamic optimizer 914 modifies the optimized code by promoting the non-empty block to contain fixup code and by replacing the commit-checkpoint operation by a partial commit-checkpoint P(fu) with associated fixup code fu. FIG. 12 illustrates an example process 1200 that may be realized by the methods and apparatus described herein. The example process 1200 of FIG. 12 begins with identifying candidate control flow graphs (CFGs) for optimization (block 1202 ). Any number of sections, regions and/or portions of a CFG may be identified by the example OPT 112 . A node from the CFG is selected (block 1204 ), in which each node may include any number of instructions, and a checkpoint operation is located within the selected node to create a placeholder block (B i ) (block 1206 ). Each example node from the example CFG may be designated with an identifier i. As such, the example nomenclature B i refers to a placeholder block associated with the i th node. The example dynamic optimizer 914 creates a control flow edge from the i th node containing the checkpoint operation and points to (i.e., directs control flow toward) the placeholder block (B i ) (block 1208 ). In the event that the example CFG and/or subset of CFGs include additional nodes (block 1210 ), then control returns to block 1204 . In the event that the example CFG and/or subset of CFGs do not include any additional nodes that have not already been analyzed by the example dynamic optimizer 914 (block 1210 ), then one or more compiler optimization(s) are allowed to proceed (block 1212 ). Any type of compiler optimization may occur including, but not limited to forward code motion optimization(s) and/or partial dead code elimination optimization(s). The example dynamic optimizer 914 selects a node from the optimized CFG and/or subset of CFGs (block 1214 ), such as the i th node. If the placeholder block (B i ) associated with the ith node is empty (block 1216 ), then B i is removed from the i th node (block 1218 ). If the optimized CFG and/or subset of CFGs include additional nodes that have not yet been analyzed (block 1220 ), then control returns to block 1214 to select another node. However, if Bi is not empty (block 1216 ), which is indicative of a circumstance where an architectural state is no longer precise in response to a checkpoint operation (e.g., C k ), then the example dynamic optimizer 914 creates fixup code FU i and associates it with label fu i (block 1222 ). Additionally, any instructions that are contained within B i based on the prior optimization are copied to FU i (block 1224 ), and the checkpoint previously located in the i th node is replaced with a partial commit-checkpoint P i (fu i ) (block 1226 ). If the optimized CFG and/or subset of CFGs include additional nodes that have not yet been analyzed (block 1220 ), then control returns to block 1214 to select another node, otherwise the example process 1200 ends. FIG. 13 is a schematic diagram of an example processor platform P 100 that may be used and/or programmed to implement any or all of the example CPU 102 , SES 103 , memory 104 , BIOS 104 , OPT 112 , fixup module 114 , fixup code generator 906 , fixup code memory 912 , dynamic optimizer 914 , partial commit-checkpoint logic module 918 and/or fixup code fetch module 920 of FIGS. 1-3 and 9 . For example, the processor platform P 100 can be implemented by one or more general-purpose processors, processor cores, microcontrollers, etc. The processor platform P 100 of the example of FIG. 13 includes at least one general-purpose programmable processor P 105 . The processor P 105 executes coded instructions P 110 and/or P 112 present in main memory of the processor P 105 (e.g., within a RAM P 115 and/or a ROM P 120 ). The processor P 105 may be any type of processing unit, such as a processor core, a processor and/or a microcontroller. The processor P 105 may execute, among other things, the example processes of FIGS. 10-13 to implement the example methods and apparatus described herein. The processor P 105 is in communication with the main memory (including a ROM P 120 and/or the RAM P 115 ) via a bus P 125 . The RAM P 115 may be implemented by dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), and/or any other type of RAM device, and ROM may be implemented by flash memory and/or any other desired type of memory device. Access to the memory P 115 and the memory P 120 may be controlled by a memory controller (not shown). The example memory P 115 may be used to implement the example fixup code memory 912 . The processor platform P 100 also includes an interface circuit P 130 . The interface circuit P 130 may be implemented by any type of interface standard, such as an external memory interface, serial port, general-purpose input/output, etc. One or more input devices P 135 and one or more output devices P 140 are connected to the interface circuit P 130 . Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.

Example methods and apparatus to manage partial commit-checkpoints are disclosed. A disclosed example method includes identifying a commit instruction associated with a region of instructions executed by a processor, identifying candidate instructions from the region of instructions, and generating a processor partial commit-checkpoint to save a current state of the processor, the checkpoint based on calculated register values associated with live instructions, and including instruction reference addresses to link the candidate instructions.

BACKGROUND As is known in the art, phased array radar systems require extensive and costly signal processing hardware and software in order to meet real-time requirements. Existing radar signal processors rely on custom built and/or specialized high-end, limited volume equipment, resulting in high capital outlay, integration and validation costs. To process large amounts of data on such systems, programmers must write code that distributes the elements of a function to multiple processors. This is an expensive process that requires specialized processing tool kits and expertise. SUMMARY It is appreciated herein that it would be desirable to provide a system for processing radar signal data having a scalable architecture based upon commercial off-the-shelf (COTS) hardware and/or software. Accordingly, a system for processing radar data comprises a plurality of detector signal data processors (SDPs) coupled to receive radar data and to generate detection data, each of the detector SDPs comprising at least one processor and a plurality of data processing units (DPUs) executing on the processor, each of the DPUs comprising an input port, a queue, a filter, and an output port, each of the DPUs to receive data into the queue via the input port, to determine data is available in the queue, to remove the available data from the queue, to process the available data using the filter, and to output the processed data at the output port. The system may further comprise an aggregator SDP coupled to receive detection data from two or more of the plurality of detector SDPs and, in response thereto, to generate a stream of plot information based upon the received detection data. In embodiments, the system also comprises a radar tracker or other external system coupled to receive the stream of plot information from the data aggregation processor. It will be appreciated that the system provides high-throughput radar signal processing without resorting to relatively expensive parallel processing tool kits. The system breaks the signal processing chain into a series of independent data processing units (DPUs) that can execute independently and in parallel. Queuing theory is used to efficiently distribute processing across multiple processor cores and/or computers. The system scales to an arbitrary number of cores/computers. The independent nature of the DPUs readily allows addition/replacement of new filters into the system. In some embodiments, the system further comprises a multiplexer coupled to receive the radar data and to select one of the plurality of detector SDPs to process the received radar data. In certain embodiments, the aggregator SDP comprises a demultiplexer to correlate and aggregate the received detection data. In some embodiments, at least one of the plurality of detector SDPs comprises a plurality of DPUs arranged in series. In embodiments, at least one of the plurality of detector SDPs comprises a DPU having an impulsive interference filter (IIF), a DPU having a Doppler filter, a DPU having a clutter filter, and a DPU having a constant false alarm rate (CFAR). In certain embodiments, the aggregator SDP further comprises a plot extractor. In some embodiments, the aggregator SDP comprises a data formatter to generate the stream of plot information according to the Structured Eurocontrol Surveillance Information Exchange (ASTERIX) standard. The plurality of detector SDPs and the aggregator SDP may be coupled via a packet-switched network and the aggregator SDP may be coupled to the radar tracker via a radar data network. In some embodiments, at least one of the detector SDPs further comprises an ingest module to receive the radar data via the packet-switched network and to copy the received radar data to the queue of at least one of the respective DPUs. In particular embodiments, a radar comprises a phased array antenna, wherein the radar data comprises blocks of data having associated elevation angles, wherein the multiplexer selects one of the plurality of detector SDPs based upon an elevation angle associated with the received radar data. In embodiments, at least one of the detector SDPs comprises two or more DPUs configured to execute on separate threads and/or as separate processes. The DPUs may use a semaphore to determine data is available in a queue. According to another aspect, a method for processing radar data comprises receiving radar data, moving the radar data to a first queue, determining the radar data is available in the first queue, removing the radar data from the first queue, processing the radar data using a first filter to generate first processed data, moving the first processed data to a second queue, determining the first processed data is available in the second queue, removing the first processed data from the second queue, processing the first processed data using a second filter to generate second processed data, performing plot detection on the second processed data to generate detection data, aggregating the detection data with other detection data to generate aggregate detection data, and performing plot extraction on the aggregate detection data to generate a stream of plot information. In some embodiments, the method further comprises providing the stream of plot information to a radar tracker. The method may employ various filters, such as an IIF, a Doppler filter, a clutter filter, a CFAR, a cell-averaging CFAR, an ordered statistic CFAR, a binary integrator, a beamformer, or an external interference cancellation filter. In embodiments, at least two different steps of the method are executed on separate threads. For example, moving radar data to a first queue may be executed on a first thread, whereas processing the radar data using a first filter to generate first processed data may be executed on a second thread. In some embodiments, determining the radar data is available in the first queue comprises reading the value of a semaphore. In some embodiments, the system and/or method may be used to process radar data comprising blocks of digital pulse compressed data. BRIEF DESCRIPTION OF THE DRAWINGS The concepts, structures, and techniques sought to be protected herein may be more fully understood from the following detailed description of the drawings, in which: FIG. 1 is a block diagram of an illustrative data processing unit (DPU); FIG. 1A is a block diagram of an illustrative arrangement of DPUs; FIG. 2 is a block diagram of an illustrative system including signal data processors (SDPs) operatively coupled to a radar; FIG. 3 is an isometric view of an active, electronically scanned array (AESA) having a panel architecture; and FIG. 4 is a schematic representation of an illustrative computer for use with the systems of FIGS. 1, 1A , and/or 2 . The drawings are not necessarily to scale, or inclusive of all elements of a system, emphasis instead generally being placed upon illustrating the concepts, structures, and techniques sought to be protected herein. DETAILED DESCRIPTION Referring to FIG. 1 , a data processing unit (DPU) 100 provides an independently and loosely coupled processing function within a signal data processing system. The illustrative DPU 100 includes an input port 102 , a queue 104 , a filter 106 , and an output port 108 . The queue 104 may use a first-in first-out (FIFO) policy, a priority-based policy, or any other suitable queuing policy known in the art. The filter 106 may be provided from any suitable combination of hardware and/or software to provide a DPU 100 having a desired signal data processing function. In some embodiments, the filter 106 comprises an impulsive interference filter (IIF), a Doppler filter (e.g., a 5-bin or 256-bin Doppler filter), a clutter filter, a constant false alarm rate (CFAR), a cell-averaging CFAR (e.g., operating on 5-bin or 256-bin Doppler filtered data), an ordered statistic CFAR (e.g., operating on 256-bin Doppler filtered data), a binary integrator, a plot extractor, a beamformer (e.g., deriving 64, or 128 azimuth beams), and/or an external interference cancellation. The input port 102 and output port 108 may represent any suitable data transfer mechanisms. For example, if the DPU 100 is provided as an object (in the object-oriented programming sense), the input port 102 may correspond to a message receiver and the output port 108 may correspond to a message sender. If the DPU 100 is provided as an application program (or “software application”) configured to execute upon a general-purpose computer (e.g., an x86-based computer), the ports 102 , 108 may correspond to inter-process communication (IPC) mechanisms available on the computer's operating system (OS), such as UNIX pipe, shared memory, or a file. If the DPU 100 is provided as a network service, the ports 102 , 108 may correspond to network endpoints. In general operation, the DPU 100 receives data into the queue 104 via the input port 102 . In some embodiments, the received data comprises one or more blocks of data. In certain embodiments, blocks of received data generally have the same fixed size. In some embodiments, the received data comprises one or more blocks of digital pulse compressed data generated by a radar. The radar may generate a stream of such blocks representative of pulse information transmitted and received by the radar. The received data is added (e.g., copied) to the queue 104 . In some embodiments, two or more threads can access the queue 104 concurrently and, therefore, a mutual exclusion object (“mutex”), semaphore, or other suitable thread safety mechanism may be employed before the received data is added to the queue. Those skilled in the art will understand that a mutex is a mechanism by which multiple threads within a program can share a resource while preventing that multiple threads do not access the resource simultaneously. Non-limiting examples of shared resources include files and memory. A mutex may be initialized when a program starts up and before threads are initialized. During initialization, a mutex is typically assigned a name that is unique within the program. Subsequently, any thread that needs to access the shared resource must obtain a “lock” on mutex; when one thread has a lock on a mutex, other threads are prevented from accessing the resource. Accordingly, a thread should “unlock” the mutex (i.e., release its lock on the mutex) when it has completed accessing the shared resource. The queue maintains data which has not yet been processed by the DPU 100 (referred to herein as “available data”). In an asynchronous manner, the DPU 100 determines that data is available in the queue 104 , removes the available data from the queue, and processes the available data using the filter 106 . In some embodiments, a semaphore is used to notify the DPU of available data, as described further in conjunction with FIG. 1A . Similar to adding data to the queue, a mutex or other thread safety mechanism may be employed before data can be safely removed from the queue. Once processing is complete, the processed data is provided via the output port 108 . Those skilled in the art will understand that the act of attempting to read the semaphore causes a reading thread to block until the semaphore is signaled by another thread (e.g., via the act of moving data into the queue). Advantageously, such blocking action causes the OS to schedule execution of another thread that is not blocked, thereby making more efficient use of available resources. In other words, execution of a given thread is inhibited until such time as data is available, giving priority to threads (and thus DPUs) having data available. Referring to FIG. 1A , an illustrative arrangement of DPUs includes a first DPU 100 a operatively coupled to receive data (e.g., radar signal data) from an external data source (not shown); second and third DPUs 100 b , 100 c operatively coupled to receive data from the first DPU 100 a ; and a fourth DPU 100 d operatively coupled to receive data from the second and third DPUs and operatively coupled to provide data to an external data sink (not shown). Any of the DPUs 100 a - 100 d may be the same as or similar to DPU 100 of FIG. 1 . In general, a DPU can receive input from one or more other DPUs (or external data sources) and can provide output to one or more other DPUs (or external data sinks). Thus, DPUs can be arranged in parallel, in series (e.g., to form a pipeline), or in any combination thereof. The DPUs 100 a - 100 d may be connected using hardware-based connections, software-based connections, or a combination of both hardware and software. Although FIG. 1A shows a particular arrangement of four DPUs, it should be understood that the concepts and techniques sought to be protected herein can be applied to any number of DPUs arranged in any desired configuration. Each of the DPUs 100 a - 100 d is generally self-contained, meaning that processing performed by one DPU does not depend upon processing performed by other DPUs. Any dependency between DPUs is managed at the system topology level via input and output port coupling. In addition, because the DPUs employ input queues, there are no timing dependencies between DPUs or other synchronization concerns. In particular embodiments, two or more of the DPUs 100 a - 100 d are provided within a common software application upon a multi-threaded OS (e.g., Linux). Here, each of the DPUs executes on a designated thread, and the OS schedules thread execution. It will be appreciated that this technique breaks data processing (e.g., radar signal data processing) into a sequence of independent processing steps (i.e., filters) and leverages existing OS schedulers to distribute these algorithms within a multi-core computer, providing high-throughput. In some embodiments, the common software application includes a dedicated thread (referred to herein as the “parent thread”) responsible for managing (e.g., “spawning” and “reaping”) child threads designated for the DPUs. In one embodiment, the parent thread is responsible for receiving input data from an external data source (e.g., a radar) and moving (e.g., copying) the input data to the first DPU 100 a . For example, as data arrives from the external data source, the parent thread moves the data to first DPU 100 a 's queue and notifies the first DPU 100 a that data is available (e.g., by incrementing a semaphore associated with the queue 104 ). In embodiments, the threads comprise Portable Operating System Interface (POSIX) threads (“pthreads”). In some embodiments, the DPUs 100 a - 100 d are provided as two or more processes configured to execute concurrently on a multitasking OS (e.g., Linux). Each of the DPUs executes within a designated process, and the OS manages process scheduling. Here, any suitable IPC technique can be used to move (e.g., copy) data between processes and provide notification of available data. In yet another embodiment, two or more of the DPUs 100 a - 100 d execute on different virtual and/or physical computing platforms. Here, any suitable networking protocols can be used to move data between the remote processes and provide notification of available data. It will be appreciated that any of the above parallel processing techniques (i.e., multi-threading, multitasking, and or using multiple computing platforms) can be combined to provide a signal data processing system that scales to any arbitrary number of processor cores and computers without requiring custom hardware or complex parallel processing software. Referring to FIG. 2 , an illustrative system 200 includes a radar 202 operatively coupled to a multiplexer 206 via a first signal path 204 , one or more signal data processors (SDPs) 210 operatively coupled to the multiplexer 206 via a second signal path 208 , and a radar tracker 214 operatively coupled to one or more of the SDPs via a third signal path 212 . The signal paths 204 , 208 , 212 are provided as any suitable combination of hardware and/or software-based signal paths. In embodiments, one or more of the signal paths 204 , 208 , 212 may include a network (or a portion thereof) operating, for example, using a packet-switched protocol (e.g., Internet Protocol (IP), Transmission Control Protocol (TCP), TCP/IP, etc.). Such a network may include relays, switches, routers, and the like. In a particular embodiment, signal paths 204 and 208 correspond to high-speed, dedicated packet-switched networks and the signal path 212 corresponds to a radar data network known in the art. In embodiments, the radar 202 is located upon a mobile platform (e.g., a land vehicle, an aircraft, or an unmanned aerial vehicle (UAV)) coupled to a remote situational display (e.g., located within a base station) via a wireless communication link. Because the bandwidth in such a link may less than that required to transmit “raw” radar pulse data, one or more SDPs 210 may be collocated with the radar upon the mobile platform. Thus, the mobile SDPs 210 analyze the radar pulse data to generate relatively low bandwidth track information which can be transmitted to the remote situational display. The illustrative system 200 includes four SDPs: a first SDP 210 a , a second SDP 210 b , a third SDP 210 c , and a fourth SDP 210 d ; in general, any number of SDPs greater than zero may be used. In embodiments, each of the SDPs 210 corresponds to a separate physical and/or virtual computing platform (e.g., a general-purpose computer comprising a multitasking, multi-threaded OS, such as Linux). In other embodiments, two or more SDPs 210 correspond to application processes executing on a common computing platform having a multitasking OS. In yet another embodiment, at least one of the SDPs 210 is provided across multiple computing platforms. As shown, a plurality of the SDPs (e.g., SDPs 210 a - 210 c ) receive data (e.g., digital pulse data) from the radar 202 via the multiplexer 206 and, therefore, are referred to herein as “detector SDPs.” In contrast, at least one of the SDPs (e.g., SDP 210 d ) receives data from more than one source (e.g., one SDP may receive detection data from two or more detector SDPs 210 a - 210 c ) and, therefore, is referred to herein as the “aggregator SDP.” In general, each of the detector SDPs 210 a - 210 c have generally the same components and functionality; thus, for clarity and simplicity of explanation, only the detector SDP 210 a will be described in detail herein. The detector SDPs 210 a , 210 b , and 210 c are coupled to the aggregator SDP 210 d via respective signal paths 209 a , 209 b , and 209 c . In some embodiments, the signal paths 209 a - 209 c and the signal path 208 correspond to portions of the same packet-switched network. The representative detector SDP 210 a comprises an ingest module 216 operatively coupled to receive data (in this example, digital pulse data) from the multiplexer 206 . A plurality of DPUs generally denoted 218 are operatively coupled to receive the pulse data from the ingest module 216 , and an output module 220 is operatively coupled to receive processed data from the plurality of DPUs 218 . A detection output module 222 is operatively coupled to receive processed data from the output module 220 and to transmit detection data to the aggregator SDP 210 d via the signal path 209 a . The various components 216 - 222 are operatively coupled via any combination of hardware and/or software-based signal paths. The representative detector SDP 210 a may include additional components and/or signal paths that are optional, unused, or disabled (e.g., the components shown with hatching in FIG. 2 ). The reason for this is discussed below in conjunction with the aggregator SDP 210 d. Although the concepts and techniques sought to be protected herein are not limited to performing any particular or specific type of processing, in one embodiment the DPUs 218 comprise an IIF 218 a , a Doppler filter 218 b , a clutter filter 218 c , a CFAR 218 d , and a binary integrator 218 e , as shown, to perform a technique for processing radar data. For simplicity of explanation, the DPUs 218 a - 218 e are referred to herein by the name of their respective filters, although it will be understood that the DPUs typically include additional elements, as shown in FIG. 1 . The DPUs 218 a - 218 e may be arranged in series to form a pipeline, as shown, with a first end of the pipeline (i.e., the IIF 218 a ) coupled to receive data from the ingest module 216 and a second end of the pipeline (i.e., the binary integrator 218 e ) coupled to the output module 220 . In embodiments, the detection output module 222 is also implemented as a DPU (i.e., the functionality described herein with respect to this module may be implemented within a DPU filter 106 of FIG. 1 ). Any of the plurality of DPUs 218 may be the same as or similar to the DPU 100 of FIG. 1 . An illustrative aggregator SDP 210 d comprises an ingest module 224 operatively coupled to receive detection data from the detector SDPs 210 a , 210 b , and 210 c via the respective signal paths 209 a , 209 b , and 209 c . The aggregator SDP 210 d further comprises a demultiplexer 226 operatively coupled to receive detection data from the ingest module, a plot extractor 228 operatively coupled to receive aggregate data from the demultiplexer 226 , an output module 230 operatively coupled to receive plot data from the plot extractor 228 , and a plot translation module 232 operatively coupled to receive plot data from the output module 230 . The various components 224 - 232 are connected via any combination of hardware and/or software-based signal paths. The plot translation module 232 receives combined detections from the plot extractor 228 and translates that information to the ASTERIX format, which may be received and used by external systems known in the art, such as the radar tracker 214 . The output module 230 may be the same as or similar to output module 220 within the detector SDP 220 a ; however, whereas the module 220 is configured to send data to the detection output module 222 , the module 230 is configured to send data to the plot translation module 232 , as shown. In embodiments, the plot extractor 228 and/or plot translation module 232 are implemented as DPUs (i.e., the functionality described herein with respect to these components may be implemented within a DPU filter 106 ( FIG. 1 ). In some embodiments, the detector SDPs 210 a - 210 c and the aggregator SDP 210 d generally include the same components and signal paths, although certain components may be unused or disabled (e.g., the components shown with hatching in FIG. 2 ). However, these different types of SDPs operate differently as a result of different configurations and/or different inputs. For example, the aggregator SDP 210 d may include a plurality of DPUs 218 ′ coupled to second ingest module 216 ′, however these DPUs are effectively disabled because the multiplexer 206 is not configured to transmit pulse data to the second ingest module 216 ′. It will be appreciated that by providing the same components in each of the SDPs 210 , the SDPs are generally interchangeable and setup and maintenance costs may be reduced. In other embodiments, an SDP 210 includes only those components and signal paths that are needed for its intended operation and, therefore, the components shown with hatching FIG. 2 may be omitted. In operation, the radar 202 transmits RF signals (e.g., pulse signals), typically using a modulation scheme as is generally known. The radar 202 receives analog signals comprising echo signals (“echos”) as well as clutter. The received analog signals are encoded using digital pulse compression coding known in the art. The encoded pulse data formatted for transmission via the signal path 204 using any suitable transmission protocol. For example, the radar 202 may segment (or “chunk”) the encoded pulse data into blocks for transmission through a packet-switched network. In embodiments, the blocks of encoded data are transmitted within IP packets, TCP/IP packets, etc. In embodiments, metadata is transmitted along with the pulse data for use by the SDPs 210 . The metadata can include, but is not limited to, the time the pulse data was generated by the radar 202 , the orientation of the radar antenna at the time the data was generated, and/or other state information regarding the radar. The multiplexer 206 receives encoded pulse data from the radar 202 , selects a target detector SDP 210 a - 210 c to process the received data, and transmits the received data to the target SDP via the signal path. This process may be repeated for each block of pulse data received. The target SDP 210 a - 210 c is selected using any suitable load balancing technique. In some embodiments, the multiplexer 206 uses a simple round-robin load balance technique. In other embodiments, the multiplexer 206 actively monitors the SDPs 210 a - 210 c to provide fault tolerance and/or dynamic load balancing. In some embodiments, the radar 202 includes an array (e.g., the active electronically steered array (AESA) of FIG. 3 ) having a plurality of subassemblies (e.g., subassemblies 314 a - 314 h of FIG. 3 ). By adjusting the phase of the signal transmitted/received by each individual element, the array is capable of producing and steering a beam having defined center angles of azimuth and elevation, and having defined angular width and height. In this case, the radar 202 transmits metadata identifying a corresponding beam azimuth and elevation angles. In turn, the multiplexer 206 can use the azimuth/elevation information to select target detector SDPs. This allows individual detector SDPs 210 a - 210 c to retain spatial awareness across radar scans without having to communicate with other detector SDPs 210 a - 210 c . For example, assuming radar 202 produces beams using twelve elevations numbered 1-12, the multiplexer 202 may target elevations 1-4 to SDP 210 a , elevations 5-8 to SDP 210 b , and elevations 9-12 to SDP 210 c. Next, the selected target detector SDP (e.g., SDP 210 a ), or more specifically the ingest module 216 therein, receives encoded pulse data from the radar 202 via the multiplexer 206 and signal path 208 . In embodiments, the ingest module 216 comprises a network service to receive pulse data from the network and to copy the received data to the queue of the first DPU in the pipeline (i.e., to the queue of the IIF 218 a ). In various embodiments, the ingest module 216 performs error checking and/or correction to handle communication errors (e.g., dropped packets, out-of-order packets, etc.) introduced by the radar 202 and/or networks 204 , 208 . Next, the pulse data is processed by each of the DPUs 218 , as described above in conjunction with FIG. 1A , to generate processed data. Advantageously, two or more of the DPUs 218 can process signal data concurrently, relying on a multitasking/multi-threading OS to schedule the work, thus improving throughput performance. Next, the output module 220 , which is coupled to the output port 108 ( FIG. 1 ) of the binary integrator 218 e , transfers the processed data to the detection output module 222 . The detection output module 222 sends detections (i.e., candidate targets) represented by the processed data provided by the plurality of DPUs 218 to the aggregator SDP 210 d. The aggregator SDP 210 d , or more specifically the ingest module 224 therein, receives detection data from one or more of the detector SDPs 210 a - 210 c via a respective signal path 209 a - 209 c . As with the ingest module 216 described above, the ingest module 224 may comprise a network service. In embodiments, the ingest module 216 listens on a first network port and the ingest module 224 listens on a second different network port. The demultiplexer 226 receives detection data from the ingest module 224 and applies correlation and aggregation techniques to generate aggregate data suitable for performing plot extraction. In one embodiment, the demultiplexer 226 uses the metadata (e.g., a radar beam azimuth and elevation angles) to reconstruct data corresponding to the full radar aperture from blocks of data corresponding to sub-apertures of the radar. It should be understood that the system 200 generally does not provide real-time behavior and, for example, unpredictable delays may be introduced by the various signal paths and processing steps. Thus, to effectively correlate processed data in time, the demultiplexer 226 may collect blocks of data (e.g., using a buffer, a bounded buffer, etc.) and perform correlation/aggregation only when a sufficient number of blocks are received for a given time period. The plot extractor 228 receives aggregate data from demultiplexer 226 and outputs a stream including digital representations of plots using any suitable technique known in the art. The plot translation module 232 receives plot information from the plot extractor 228 and formats the data for transmission through the network 212 , which may comprise a radar data network. In some embodiments, the data is formatted according to the All Purpose Structured Eurocontrol Surveillance Information Exchange (ASTERIX) standard. As is known in the art, the formatted data may be used by a radar tracker 214 via the network 212 to form and update target tracks. Referring to FIG. 3 , the systems and techniques described above in conjunction with FIGS. 1, 1A, and 2 may be used in a radar system which includes an active electronically steered array (AESA) 300 . In some embodiments, the AESA 300 includes an antenna panel 312 (also referred to as a “panel array”) coupled to an integrated panel array assembly (IPAA) 314 . Antenna panel 312 is thin and generally planar and has a plurality of antenna elements generally denoted 313 , disposed to transmit and receive RF energy through a first surface 312 a thereof. Antenna elements 313 are shown in phantom since they are typically below external surface 312 a and thus not directly visible in FIG. 3 . In one example, the antenna elements 313 may be provided as a stacked patch antenna antenna elements configured for operation in the X-band frequency range and panel array is provided having a thickness, T in the range of about 0.003 meter (m) to about 0.01 m (with a thickness typically of about 0.005 m being preferred) and having a width, W, of about 0.5 m and a length, L, of about 0.5 m with 1024 patch antenna elements (not all shown visible in FIG. 3 ). The IPAA 314 is provided from a plurality of subassemblies mechanically coupled together, with eight subassemblies 314 a - 314 h shown in this example. Each of the subassemblies 314 a - 314 h includes a corresponding one of a plurality of active panels 318 a - 318 h and a corresponding one of a plurality of cold plates 342 a - 342 h (cold plates 342 e - 342 g are not shown). The cold plates 342 a - 342 h cool corresponding ones of the active panels 318 a - 318 h . The cold plates 342 a - 342 h may be air cooled, liquid cooled, or both. Each of active panels 318 a - 318 h is electrically coupled to the antenna panel 312 via a first surface thereof. A second surface (not visible) of active panels 318 a - 318 h have active circuits (not visible in FIG. 3 ) disposed thereon. In one embodiment, the AESA 310 comprises eight subassemblies 314 a - 314 h in one 0.5 m×0.5 m assembly (i.e., L=0.5 m and W=0.5 m in FIG. 3 ). In other embodiments, fewer or more than eight subassemblies 314 a - 314 h may be used to provide an AESA having dimensions of 0.5 m×0.5 m. Also, the AESA may be provided having sizes other than 0.5 m×0.5 m. One of ordinary skill in the art will appreciate how to select the number of subassemblies to include in an AESA as well as the length, L, and width, W, required for a particular application. Since the subassemblies 314 a - 314 h are independent, they are sometimes referred to as line replaceable units (LRUs) which indicates that if one of subassemblies 314 a - 314 h were to fail or begin to operate incorrectly or with degraded performance, the subassembly could be removed and a new subassembly could be inserted in its place. Some or all of the outputs from the individual subassemblies 314 a - 314 h may be provided to an input of an SDP which may be the same as or similar to SDPs 210 a - 210 d described above in conjunction with FIG. 2 . The various SDP outputs may also be aggregated. By appropriate selection of the active components coupled thereto, the active panels 318 a - 318 h may be configured to provide a wide range of RF power levels and radar waveforms including short and long transmit pulses at multiple pulse repetition frequencies (PRFs). Different power levels are achieved by appropriate selection of the active components provided as part of the active panels 318 a - 318 h . In some examples, monolithic microwave integrated circuit (MMIC) technologies are preferred and can be used to provide systems which operate with relatively low power T/R channels (e.g., less that about 1 watt (W) per T/R channel). Also, MMIC may be implemented using flip-chip attached circuits in the active panels 318 a - 318 h to provide low power per T/R Channels. Also, flip-chip attached SiGe or RF (radio frequency) CMOS (complementary metal oxide semiconductor) circuits may be used in the active panels 318 a - 318 h to achieve medium power channels (e.g., in the range of about 1 W to about 10 W per T/R transmit channel). Also, flip-chip circuits may be used in the active panels 318 a - 318 h to provide high power channels. It should thus be appreciated that one panel architecture can handle T/R channel RF output peak power from milli-watts (mW) to tens of watts and average power from mW to watts. Thus, by populating the active panels 318 a - 318 h with different types of active circuits (e.g., different types of ICs), the active panels 318 a - 318 h may be appropriate for use in different types of radar or other RF systems. The IPAA 314 described herein efficiently transfers heat (i.e., thermal energy) from an active panel 318 to a corresponding cold plate 342 . Mounting the cold plate 342 directly to the active circuits (not shown) would reduce the number of thermal interfaces between the active circuits and the cold plate. However, due to the varying thickness of the active circuits and bows in the active panel 318 for which the active circuits are attached as well as bows in the cold plate 342 itself, interfacing each and every active circuit is difficult. Therefore, an IPAA 314 that mitigates these variances and provides a thermal interface between the active circuits and the cold plate 342 allows for an efficient transfer of dissipated thermal energy from the active circuits. As will be described further, a thermal conductive material connecting the active circuits with the cold plate 342 allows for efficient transfer of heat from the active circuits. FIG. 4 shows an illustrative computer or other processing device 400 that can perform at least part of the processing described herein. The computer 400 includes a processor 402 , a volatile memory 404 , a non-volatile memory 406 (e.g., hard disk), an output device 408 and a graphical user interface (GUI) 410 (e.g., a mouse, a keyboard, a display, for example), each of which is coupled together by a bus 418 . The non-volatile memory 406 stores computer instructions 412 , an operating system 414 , and data 416 . In one example, the computer instructions 412 are executed by the processor 402 out of volatile memory 404 . In one embodiment, an article 420 comprises non-transitory computer-readable instructions. Processing may be implemented in hardware, software, or a combination of the two. In embodiments, processing is provided by computer programs executing on programmable computers/machines that each includes a processor, a storage medium or other article of manufacture that is readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and one or more output devices. Program code may be applied to data entered using an input device to perform processing and to generate output information. The system can perform processing, at least in part, via a computer program product, (e.g., in a machine-readable storage device), for execution by, or to control the operation of, data processing apparatus (e.g., a programmable processor, a computer, or multiple computers). Each such program may be implemented in a high level procedural or object-oriented programming language to communicate with a computer system. However, the programs may be implemented in assembly or machine language. The language may be a compiled or an interpreted language and it may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program may be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network. A computer program may be stored on a storage medium or device (e.g., CD-ROM, hard disk, or magnetic diskette) that is readable by a general or special purpose programmable computer for configuring and operating the computer when the storage medium or device is read by the computer. Processing may also be implemented as a machine-readable storage medium, configured with a computer program, where upon execution, instructions in the computer program cause the computer to operate. Processing may be performed by one or more programmable processors executing one or more computer programs to perform the functions of the system. All or part of the system may be implemented as special purpose logic circuitry (e.g., an FPGA (field programmable gate array) and/or an ASIC (application-specific integrated circuit)). All references cited herein are hereby incorporated herein by reference in their entirety. A non-transitory machine-readable medium may include but is not limited to a hard drive, compact disc, flash memory, non-volatile memory, volatile memory, magnetic diskette and so forth but does not include a transitory signal per se. Having described certain embodiments, which serve to illustrate various concepts, structures, and techniques sought to be protected herein, it will be apparent to those of ordinary skill in the art that other embodiments incorporating these concepts, structures, and techniques may be used. Accordingly, it is submitted that that scope of the patent should not be limited to the described embodiments but rather should be limited only by the spirit and scope of the following claims.

A system provides high-throughput radar signal processing without resorting to costly parallel processing tool kits. The system breaks the signal processing chain into a series of independent data processing units (DPUs) that execute independently and in parallel. Queuing theory is used to efficiently distribute processing across multiple processor cores and/or computers. The system scales to an arbitrary number of cores/computers. The independent nature of the DPUs readily allows addition/replacement of new filters into the system.

CROSS-REFERENCE TO RELATED APPLICATIONS Not applicable. STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH Not applicable. FIELD OF THE INVENTION The present invention relates to energy treatment systems and more particularly to a system for positioning and protecting an electromagnetic energy delivery handpiece adapted for treating a selected area of tissue. BACKGROUND OF THE INVENTION Lasers and other such devices are used in various surgical procedures for therapeutically treating tissue, such as skin tissue. For example, medical lasers are used to treat naturally occurring skin lesions and discolorations including freckles, age spots, birth marks, melanomas, nevi, and lentigines. Lasers are also used to remove other visible skin features such as tattoos and "port wine" stain birth marks which are caused by a plurality of enlarged blood vessels. A patient may choose to have such skin features treated for cosmetic reasons and/or medical necessity. Generally a medical laser for use in treating skin tissue has a handpiece adapted for manipulation by an operator. The handpiece is coupled to a source of laser energy by a cable that can have an optical fiber for carrying the laser energy to the handpiece. The handpiece is guided to a predetermined distance from the treatment area, i.e., skin surface, by a distance gauge or standoff. For example, U.S. Pat. No. 5,217,455 discloses a method for treating skin tissue with laser energy emitted from a medical laser handpiece having a distance gauge that is placed against the skin to focus the laser energy to a chosen treatment area. The distance gauge is a rod-like member extending from a distal end of the handpiece. U.S. Pat. No. 5,454,807 discloses a catheter-type laser energy delivery system for treating tissue. The catheter used with such a system includes a distal tip assembly having a body with an optical fiber disposed therein. An adjustable standoff extends from alongside the body to maintain a proper distance from the end of the optical fiber and the surface of the tissue to be treated. The above-cited references are incorporated by reference herein. To treat a portion of skin, a suitably trained operator positions the handpiece in a desired location with the standoff placed in contact with the skin of a patient. The standoff maintains a predetermined distance between the handpiece and the skin surface. The operator activates the handpiece to energize a desired tissue area. As the laser energy contacts skin tissue, debris in the form of energized skin tissue is projected away from the treatment site. This tissue debris can be propelled to the energy-emitting end of the optical fiber thereby distorting and/or blocking the flow of laser energy to the treatment area. It would be desirable to provide a system for focusing energy to a desired treatment site, while also protecting a energy delivery handpiece from tissue debris emanating from the treatment site. SUMMARY OF THE INVENTION The present invention provides a system for positioning and focusing an electromagnetic energy delivery system, such as a laser energy delivery system, at a selected treatment site. In one embodiment, the system includes an energy transmissive member positioned at a predetermined distance from a distal end of the laser handpiece. The energy transmissive member protects the laser handpiece from tissue eruptions as laser energy is applied to the treatment site. In one embodiment, the energy transmissive member also focuses laser energy upon the treatment site. Although the invention is primarily shown and described in conjunction with a laser system and handpiece for treating skin tissue, it is understood that the invention is applicable in a variety of additional electromagnetic energy delivering surgical instruments and procedures. The system includes an energy transmissive member adapted for placement on or near a selected area of tissue to focus laser energy to a treatment site. In one embodiment, the energy transmissive member is removably and replaceably secured to a spacer member which itself is mountable upon a laser handpiece. This coupling arrangement enables the energy transmissive member to be secured in a predetermined position with respect to the laser handpiece. The advantages of the system include the ability of the energy transmissive member to protect the handpiece from soiling by any tissue eruptions that may occur at the treatment site. Further, the energy transmissive member can be used to focus the laser energy from the handpiece to the treatment site as well. To effect treatment of a selected tissue area, the handpiece is manipulated by an operator to position the handpiece relative to the treatment site. The energy transmissive member is placed in proximity to the treatment site and the handpiece is actuated by the operator to emit laser energy. Laser energy is then focussed, optionally with the aid of the transmissive member, to a desired location at or below a surface of the tissue. The presence of the transmissive member in proximity to the treatment site and spaced apart from the handpiece prevents any tissue debris from contacting the handpiece and blocking or distorting the laser energy emitted from the handpiece. In another embodiment of the invention, a laser positioning system includes a supply of energy transmissive members, each having different thicknesses and shapes. The energy transmissive members can be secured directly to the laser handpiece, or mounted on a spacer member that is affixed to the laser handpiece. A surgeon can select a suitable energy transmissive member that is most effective to focus laser energy at a treatment site at or below a tissue surface of the tissue. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be more fully understood from the following description of the drawings in which: FIG. 1 is a schematic view of the laser positioning system according to the present invention; FIG. 2 is a perspective view of a portion of the laser positioning system shown in FIG. 1; FIG. 3 is a perspective view of a portion of the laser positioning system of FIG. 1; FIG. 4 is a top view, in partial cross-section along lines 4--4, of a portion of the laser positioning system of FIG. 2; FIG. 5 is a cross-sectional view of the laser positioning system of FIG. 4 along lines 5--5; FIG. 6A is a front view of an exemplary embodiment of a spacer member forming a portion of a laser positioning system according to the present invention; and FIG. 6B is a front view of an alternate embodiment of the spacer member of FIG. 6A. DETAILED DESCRIPTION OF THE INVENTION FIGS. 1-2 illustrate an exemplary electromagnetic energy delivery positioning system, such as a laser positioning system 10, in accordance with the present invention. The system 10 includes an electromagnetic energy source 11, such as a source of laser energy. An optical fiber system 15 conveys the energy from source 11 to a handpiece 12 which can be manipulated by a surgeon. A distal end 13 of optical fiber may extend from a distal end 19 of handpiece 12. The system further includes a spacer member 14 having a proximal end 18 that is mountable upon the handpiece 12 and a distal end 20. The distal end 20 of spacer member 14 is constructed, as described below, so as to be able to selectively engage an energy transmissive member 16 that is removably and replaceably mounted thereon. With the aid of the spacer member 14, the energy transmissive member 16 can be positioned on or near a treatment site and separated from the handpiece 12 by a predetermined distance. The energy transmissive member 16 is effective to protect the distal end of the handpiece 12, including the optical fiber 13 and any lens (not shown) coupled therewith, from tissue debris that may erupt from the treatment site 25 as laser energy contacts the tissue. Optionally, the energy transmissive member 16 can also be used to focus laser energy at the treatment site 15. The laser positioning system 10 is useful in conjunction with a variety of medical lasers for treating selected areas of skin tissue to treat a variety of dermatological conditions, including the removal of freckles, age spots, birth marks, lesions, tattoos, hair and varicose veins. The type of laser energy to be applied to the target tissue is selected based on the properties of a particular type of laser energy in conjunction with the characteristics of the tissue to be treated. Exemplary useful lasers include diode, Alexandrite, ruby, pulsed dye, and gas ion lasers. The applied laser energy is defined by various characteristics including wavelength, pulse duration, fluence, spot size, and peak and average power. The laser energy characteristics are selected in accordance with the intended application and the particular needs of a given patient. The wavelength of the laser energy can range up to about 810 nanometers and is typically applied in pulses as known to one of ordinary skill in the art. The spacer member 14 can have a variety of configurations that securely position the energy transmissive member 16 at a desired distance from the laser handpiece 12. The spacer member 14 should be of sufficient rigidity to resist pressure applied to the handpiece 12 by an operator, and it should not significantly obstruct the operator's view. In one embodiment, the spacer member 14 includes a proximal end 18 that mounts upon the handpiece 12 and a distal end 20 for receiving and holding an energy transmissive member 16. One or more elongate members 22 can extend between the proximal and distal ends 18,20 of the spacer member 14. The elongate member 22 can vary in length to achieve a desired distance between the distal end of the optical fiber 13 and the energy transmissive member 16. One of ordinary skill in the art can readily determine a suitable length for the elongate member 22. In an exemplary embodiment, the length of the elongate member can range from about 5 to 15 mm. The elongate member 22 can be of a predetermined length, or it can have an adjustable length. Where the elongate member 22 does not have an adjustable length, a plurality of elongate members 22, each with different lengths, may be provided as part of a system. An elongate member of a desired length can be selected as appropriate for a given procedure. FIGS. 6A and 6B show exemplary adjustable length spacer members. In FIG. 6A, the elongate member 22' of the spacer member 14' includes a series of sections 23 arranged in a telescoping configuration. The distal end 20' of the spacer member 14' can be extended and retracted with respect to the proximal end 18' to provide a selected length for the elongate member 22'. In FIG. 6B, the distal end 20" of the spacer member 14" is slidable along the elongate member 22". The distal end 20" is secured in position by means of a set screw 25 that impinges upon the elongate member 22". The elongate member 22" can also include a series of spaced markings 27 that indicate the position of the distal end 20" with respect to the elongate member. The proximal end 18 of the spacer member 14 can be adapted for permanent or removable engagement to the handpiece. Removable engagement mechanisms include a ring, mountable upon the handpiece and having a threaded inner portion for engagement with complementary threads on the handpiece. Other removable engagement mechanisms may also be used to attach proximal end 18 to hand piece 12, including detent mechanisms and other positive and/or negative surface features. The proximal end 18 may be permanently attached to the handpiece by a variety of techniques including adhesive bonding and welding. In one embodiment shown in FIG. 3, the proximal end 18 of the spacer member 14 includes a ring 28 coupled to a first end 24 of the elongate member 22. The ring 28 includes a threaded inner surface 29 for removable engagement with complementary threads (not shown) disposed on the handpiece 12. The distal end 20 of the spacer member 14 is secured to or is integral with a second end 26 of the elongate member 22. The distal end 20 is adapted to receive and secure at least one energy transmissive member 16. The distal end 20 of the spacer member 14 can be formed in a variety of configurations such that the energy transmissive member 16 remains in a fixed position and resists displacement in the presence of downward pressure applied to the handpiece 12 by the operator. The distal end 20 can be adapted for permanent or removable insertion of an energy transmissive member. The distal end 20 of the spacer member 14 can include one or more positive and/or negative surface features for engaging complementary surface features of the energy transmissive member 16. Such surface features can provide an interference or snap-fit engagement between the transmissive member 16 and the distal end 20. Alternatively, threads can be formed on an outer surface of an energy transmissive member 16 to engage complementary threads on the distal end 20 of the spacer member 14. FIGS. 4-5 show exemplary embodiments of the distal end 20 of the spacer member 14 having an energy transmissive member 16 secured thereto. The distal end 20 of the spacer member 14 includes an annular member 30 extending from the second end 26 of the elongate member 22. The annular member 30 has an inner surface with a boss 32 disposed thereon. The boss 32 is adapted for engagement within a negative surface feature 34, in the form of a groove, that is formed about the circumference of the energy transmissive member 16. The groove 34 can have a beveled portion 36 to facilitate the insertion of the energy transmissive member 16 within the annular member 30. It is understood other embodiments to secure the energy transmissive member to the spacer member will be readily apparent to one of ordinary skill in the art. One of ordinary skill in the art will readily appreciate that the overall shape and dimensions of the energy transmissive member 16 can vary. The energy transmissive member 16 can be cylindrical, square, triangular, and multi-sided. Similarly, the thickness of the energy transmissive member can be relatively constant or can vary in a manner similar to that of an optical lens. That is, the energy transmissive member 16 can be bi-convex, plano-convex, convexo-concave, bi-concave, plano-concave, and concavo-convex. In one embodiment, the energy transmissive member 16 is cylindrical, i.e., lens-shaped, with a slightly convex entry surface 38 and a slightly concave exit surface 40. The entry surface 38 is curved to reduce the amount of energy that is reflected directly back to the distal end of the optical fiber 13 (FIG. 1). The exit surface 40 is sufficiently concave to focus the laser energy to a predetermined distance from the energy transmissive member 16. It is understood, however, that the energy transmissive member 16 can be shaped such that the laser energy does not converge, or such that it diverges slightly. As noted above, the dimensions of the energy transmission member will vary depending upon the requirements of a given application. One of ordinary skill in the art will readily appreciate suitable dimensions. In an exemplary embodiment, however, the thickness of the energy transmissive member 16 can vary from about one millimeter to about ten millimeters. Further, the cross-sectional area of the entry surface 38 can range from about 0.01 square centimeter to about 5.00 square centimeters. It is understood that a laser positioning system may include a selection of energy transmissive members, each with different shapes, dimensions and optical properties. Once a selected treatment area is identified, an operator selects a particular energy transmissive member 16 having appropriate thickness and, optionally, focusing properties. The operator then determines a desired distance between the optical fiber 13 and the energy transmissive member 16 and selects a spacer member 14 with a suitable length or adjusts the elongate member 22 to a desired length. The appropriate energy transmissive member 16 is then secured to the coupling mechanism 20 such that the energy transmissive member is fixedly positioned with respect to the optical fiber 13 and the handpiece 12. Once the system is assembled, the operator can manipulate the handpiece 12 such that the energy transmissive member 16 rests on the surface of the tissue. The operator then actuates the system to apply laser energy to the treatment site 25 in accordance with predetermined exposure criteria. The laser energy is then focused to a location at or below the surface of the treatment site, with or without the aid of the energy transmissive member 16. The distance below the skin surface to which the laser energy is focused can vary from about zero to about five millimeters. The positional relationship of the energy transmissive member 16 and the surface of tissue, i.e., the epidermal layer, remains substantially constant even as the operator applies pressure to the handpiece. That is, the tissue-contacting surface of the energy transmissive member 16 can impinge upon the tissue surface, but the depth of target tissue below the tissue surface with respect to the tissue-contacting surface remains constant. Thus, handpiece pressure does not alter the depth below the tissue surface to which the laser energy penetrates tissue. During the course of treating tissue with laser energy, tissue eruptions may occur and tend to splatter the handpiece with tissue debris. Such debris can adhere to and block the distal end of the optical fiber 13, and tend to block or distort laser energy. The energy transmissive member 16 is effective to protect the distal end of the optical fiber 13 and the handpiece 12 from fouling due to such tissue eruptions. The laser positioning system preferably includes a series of energy transmissive members 16, each having different dimensions and optical characteristics. Each of the energy transmissive members 16 are removably and replaceably mountable to the spacer member 14 and can be disposed of after use. Prior to conducting a surgical procedure, an operator selects an energy transmissive member 16 that is appropriate for a particular treatment site and/or tissue depth and secures it in the spacer member 14. Alternatively, a spacer member of a suitable length, with a desired pre-attached energy transmissive member is secured to the handpiece 12. The operator then manipulates the handpiece 12 into position and applies laser energy to a treatment site. The selected energy transmissive member 16 protects the distal end of the optical fiber 13 from tissue debris, that may result from the treatment. Optionally, the energy transmissive member 16 is effective to focus the laser energy upon the treatment site. The components of the laser positioning system are selected from materials suitable for the particular component. For example, the spacer member 14 can be formed from a suitably rigid material including polymers and metals such as stainless steel and aluminum. An exemplary embodiment uses a stainless steel spacer member. The energy transmissive member 16 can be formed from a variety of materials well known to those having ordinary skill in the art, that allow the passage of laser energy. Suitable materials include glass, polymers, sapphire and quartz. Having described the preferred embodiments of the invention, it will now become apparent to one of ordinary skill in the art that other embodiments incorporating their concepts may be used. Therefore, the invention is not be limited to the particular embodiments disclosed herein, but rather only by the spirit and scope of the appended claims. All publications and references cited herein are expressly incorporated herein by reference in their entirety.

A system is provided to position an energy delivery handpiece a desired distance from a treatment site while at the same time protecting the handpiece, and energy transmitting optical fibers, from soiling due to tissue debris. The system includes one or more energy transmissive members that are formed from a material that allows the passage of electromagnetic (e.g., laser) energy therethrough. The energy transmissive members can be removably and replaceably attachable to one end of a spacer member. An opposite end of the spacer member is mountable to the energy delivery handpiece. The energy transmissive member is effective protect the handpiece from tissue eruptions. In one embodiment the energy transmissive member also is effective to focus electromagnetic energy upon the treatment site.

TECHNICAL FIELD This invention relates to compounds having biological activity to inhibit lipoxygenase enzymes, to pharmaceutical compositions comprising these compounds, and to a medical method of treatment. More particularly, this invention concerns certain heteroatom substituted propanyl compounds which inhibit leukotriene biosynthesis, to pharmaceutical compositions comprising these compounds and to a method of inhibiting lipoxygenase activity and leukotriene biosynthesis. BACKGROUND OF THE INVENTION 5-Lipoxygenase is the first dedicated enzyme in the pathway leading to the biosynthesis of leukotrienes. This important enzyme has a rather restricted distribution, being found predominantly in leukocytes and mast cells of most mammals. Normally 5-lipoxygenase is present in the cell in an inactive form; however, when leukocytes respond to external stimuli, intracellular 5-lipoxygenase can be rapidly activated. This enzyme catalyzes the addition of molecular oxygen to fatty acids with cis, cis-1,4-pentadiene structures, convening them to 1-hydropcroxy-trans, cis-2,4-pentadienes. Arachidonic acid, the 5-lipoxygenase substrate which leads to leukotriene products, is found in very low concentrations in mammalian cells and must first be hydrolyzed from membrane phospholipids through the actions of phospholipases in response to extracellular stimuli. The initial product of 5-lipoxygenase action on arachidonate is 5-HPETE which can be reduced to 5-HETE or convened to LTA 4 . This reactive leukotriene intermediate is enzymatically hydrated to LTB 4 or conjugated to the tripeptide glutathione to produce LTC 4 . LTA 4 can also be hydrolyzed nonenzymatically to form two isomers of LTB 4 . Successive proteolytic cleavage steps convert LTC 4 to LTD 4 and LTE 4 . Other products resulting from further oxygenation steps have also been described in the literature. Products of the 5-lipoxygenase cascade are extremely potent substances which produce a wide variety of biological effects, often in the nanomolar to picomolar concentration range. The remarkable potencies and diversity of actions of products of the 5-lipoxygenase pathway have led to the suggestion that they play important roles in a variety of diseases. Alterations in leukotriene metabolism have been demonstrated in a as number of disease states including asthma, allergic rhinitis, rheumatoid arthritis and gout, psoriasis, adult respiratory distress syndrome, inflammatory bowel disease, endotoxin shock syndrome, atherosclerosis, ischemia induced myocardial injury, and central nervous system pathology resulting from the formation of leukotrienes following stroke or subarachnoid hemorrhage. The enzyme 5-lipoxygenase catalyzes the first step leading to the biosynthesis of all the leukotrienes and therefore inhibition of this enzyme provides an approach to limit the effects of all the products of this pathway. Compounds which inhibit 5lipoxygenase are thus useful in the treatment of disease states such as those listed above in which the leukotrienes play an important role. SUMMARY OF THE INVENTION In its principal embodiment, the present invention provides certain heteroatom substituted propanyl compounds which inhibit lipoxygenase enzyme activity and are useful in the treatment of allergic and inflammatory disease states in which leukotrienes play a role. The compounds of this invention and their pharmaceutically acceptable salts have the structure ##STR5## where L 1 and L 2 are independently a single bond or are independently selected from the group consisting of alkylene of one to three carbon atoms, propenylene, and propynylene. L 3 is selected from the group consisting of (a) ##STR6## and (b) ##STR7## where R 13 is hydrogen or alkyl of one to four carbon atoms, R 14 is alkyl of one to four carbon atoms, and R 15 is hydrogen or alkyl of one to four carbon atoms. Y is selected from oxygen, >NR 12 where R 12 is hydrogen or alkyl of one to four carbon atoms, and >S(O) n where n=0, 1, or 2. R 1 is alkyl of one to four carbon atoms; and R 2 is selected from the group consisting of (a) alkenyl of one to four carbon atoms, (b) ##STR8## (c) ##STR9## and (d) ##STR10## where W is oxygen or sulfur, Z is --CH 2 --, oxygen, sulfur, or --NR 11 wherein R 11 is hydrogen or alkyl of one to four carbon atoms. R 9 is alkyl of one to four carbon atoms, or R 1 and R 9 , together with the nitrogen atoms to which they are attached, define a ring selected from the group consisting of ##STR11## where R 10 is selected from the group consisting of (a) hydrogen, (b) alkyl of one to four carbon atoms, (c) haloalkyl of one to four carbon atoms, (d) cyanoalkyl of one to four carbon atoms, (c) unsubstituted phenyl, (f) phenyl substituted with a substituent selected from the group consisting of alkyl of one to four carbon atoms, alkoxy of one to four carbon atoms, haloalkyl, of one to six carbon atoms, and halogen, (g) hydroxyalkyl of one to four carbon atoms, (h) aminoalkyl of one to four carbon atoms, (i) carboxyalkyl of one to four carbon atoms, (j) (alkoxycarbonyl)alkyl where the alkyl and alkoxy portions each are of one to four carbon atoms, and (k) (alkylaminocarbonyl)alkyl, where the alkyl portions are independently of one to four carbon atoms. R 3 , R 4 , R 5 , and R 6 are independently selected from the group consisting of hydrogen, alkyl of one to four carbon atoms, alkoxy of one to four carbon atoms, haloalkyl of one to four carbon atoms, halogen, cyano, amino, alkoxycarbonyl of one to four carbon atoms, and dialkylaminocarbonyl where the alkyl portions are each of one to four carbon atoms. R 7 and R 8 are alkyl of one to four carbon atoms, or taken together with the oxygen atoms to which they are attached and the carbon atoms to which the oxygen atoms in turn are attached, form a ring of the structure where R 16 and R 17 are independently selected from the group consisting of hydrogen, alkyl of one to four carbon atoms, alkoxy of one to four carbon atoms, and haloalkyl of one to four carbon atoms. In another embodiment, the present invention provides pharmaceutical compositions which comprise a therapeutically effective amount of compound as defined above in combination with a pharmaceutically acceptable carder. In yet another embodiment, the present invention provides a method of inhibiting leukotriene biosynthesis in a host mammal in need of such treatment comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound as defined above. DETAILED DESCRIPTION OF THE INVENTION Definitions of Terms As used throughout this specification and the appended claims, the term is "alkyl" refers to a monovalent group derived from a straight or branched chain saturated hydrocarbon by the removal of a single hydrogen atom. Alkyl groups are exemplified by methyl, ethyl, n- and iso-propyl, n-, sec-, iso- and tert-butyl, and the like. The term "alkylamino" refers to a group having the structure --NHR'wherein R' is alkyl as previously defined. Example of alkylamino include methylamino, ethylamino, iso-propylamino, and the like. The term "alkylaminocarbonyl" refers to an alkylamino group, as previously defined, attached to the parent molecular moiety through a carbonyl group. Examples of alkylaminocarbonyl include methylaminocarbonyl, ethylaminocarbonyl, isopropylaminocarbonyl, and the like. The term "alkanoyl" refers to an alkyl group, as defined above, attached to the parent molecular moiety through a carbonyl group. Alkanoyl groups are exemplified by formyl, acetyl, butanoyl, and the like. The term "propanyl" refers to a straight chain, three-carbon group containing a carbon-carbon triple bond. The term "hydroxyalkyl" represents an alkyl group, as defined above, substituted by one to three hydroxyl groups with the proviso that no more than one hydroxy group may be attached to a single carbon atom of the alkyl group. The term "haloalkyl" denotes an alkyl group, as defined above, having one, as two, or three halogen atoms attached thereto and is exemplified by such groups as chloromethyl, bromoethyl, trifluoromethyl, and the like. The terms "alkoxy" and "alkoxyl" denote an alkyl group, as defined above, attached to the parent molecular moiety through an oxygen atom. Representative alkoxy groups include methoxyl, ethoxyl, propoxyl, butoxyl, and the like. The term "alkoxycarbonyl" represents an ester group; i.e. an alkoxy group attached to the parent molecular moiety through a carbonyl group. Representative alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, and the like. The term "alkenyl" denotes a monovalent group derived from a hydrocarbon containing at least one carbon-carbon double bond by the removal of a single hydrogen atom. Alkenyl groups include, for example, ethenyl, propenyl, butenyl, 1-methyl-2-buten-1-yl and the like. The term "alkylene" denotes a divalent group derived from a straight or branched chain saturated hydrocarbon by the removal of two hydrogen atoms, for example methylene, 1,2-ethylene, 1,1-ethylene, 1,3-propylene, 2,2dimethylpropylene, and the like. The term "aminoalkyl" denotes an --NH 2 group attached to the parent molecular moiety through an alkylene group. Representative aminoalkyl groups include 2-amino-1-ethylene, 3-amino-1-propylene, 2-amino-1-propylene, and the like. The term "carboxyalkyl" denotes a --CO 2 H group attached to the parent molecular moiety through an alkylene group. Representative carboxyalkyl groups include, 1-carboxyethyl, 2-carboxyethyl, 1-carboxypropyl, and the like. The term "(alkoxycarbonyl)alkyl" denotes an alkoxycarbonyl group, as defined above, attached to the parent molecular moiety through an alkylene group. Representative (alkoxycarbonyl)alkyl groups include ethoxycarbonylmethyl, ethoxycarbonylethyl, methoxycarbonylpropyl, and the like. The term "(alkylaminocarbonyl)alkyl" denotes an alkylaminocarbonyl group, as defined above, attached to the parent molecular moiety through an alkylene group. Examples of (alkylaminocarbonyl)alkyl groups include methylaminocarbonylmethyl, methylaminocarbonylpropyl, isopropylaminocarbonylmethyl, and the like. The term "alkenylene" denotes a divalent group derived from a straight or branched chain hydrocarbon containing at least one carbon-carbon double bond. Examples of alkenylene include --CH═CH--, --CH 2 CH═CH--, --C(CH 3 )═CH--, --CH 2 CH═CHCH 2 --, and the like. By "pharmaceutically acceptable salt" it is meant those salts which are, within the scope of sound medical judgement, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk milo. Pharmaceutically acceptable salts are well known in the art. For example, S. M Berge, et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66: 1-19. The salts can be prepared in situ during the final isolation and purification of the compounds of the invention, or separately by reacting the free base function with a suitable organic acid. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphersulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laumte, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerote salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetmethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like. PREFERRED EMBODIMENTS Compounds contemplated as falling withing the scope of the present invention include, but are not limited to: E-(4S )-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4R )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, E-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, Z-(4R )-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl}phenyl)oximinomethyl]-1,3-dioxolane, E-(4R )-O-methyl-2,2-dimethyl-4-[(5- fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl}phenyl)oximinomethyl]-13-dioxolane, Z-(4R )-O-methyl- 2,2-dimethyl-4-[(5- fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13-dioxolane, E-(4R)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13-dioxolane, Z-(4S )-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, E-(4S)-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfinyl)phenyl)oximinomethyl]-13-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfinyl)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfonyl)phenyl)oximinomethyl]-13-dioxolane, E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfonyl)phenyl)oximinomethyl]-13-dioxolane, Z-(4S ) -O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethyl aminothiocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N'-dimethylaminothiocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-((N', N'-dimethylaminocarbonyl)-N-methylamino)benzylthioxy)phenyl)oximinomethyl]-13-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzylthioxy)phenyl)oximinomethyl]-13-dioxolane, anti-(1 S, 2R)- 1-[(5-fluoro3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl) ]-1,2,3-trimethoxypropane, anti-(1S, 2R)-1-[(5-fluoro-3-{4-(N-acetyl-N-methylamino)benzyloxy)phenyl)]-1,2,3 -trimethoxypropane, anti-(1S, 2R)-1-[3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, anti-(1S, 2R)- 1-[3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, anti-(1S, 2R)-1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzylthioxyl)phenyl]-1,2,3-trimethoxypropane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-(N', N'-dimethylaminocarbonyl-N-methylamino)methyl)benzyloxy)phenyl)oximinomethyl]-13-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-(N', N'-dimethylaminocarbonyl-N-methylamino)methyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(imidazolidin-2-on-1-ylmethyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(imidazolidin-2-on-1-ylmethyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, Z- (1S)-O-methyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]]-1,2-dimethoxyethane, E-(1S)-O-methyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]]-1,2-dimethoxyethane, Z-(1S)-O-methyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane, E-(1S)-O-methyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane, E-(1S)-O-methyl-4- [(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane, Z-(1S)-O-methyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane, E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-acetyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-acetyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, E-(4S )-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino) thioxyl)phenyl)oximinomethyl]-13-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, anti-(1S, 2R)-1-[5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]- 1,2,3-trimethoxypropane, anti-(1S, 2R)- 1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl]-1,23-trimethoxypropane, E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-(4-methylpipemzin-1-ylcarbonyl)-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-(4-methylpipemzin-1-ylcarbonyl)-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-dioxlane, anti-(1S, 2R)-1-[3-(4-(N-(4-methylpipemzin-1-ylcarbonyl)-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-aminoprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13dioxolane Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-aminoprop-1-yl) aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(4-hydroxybut- 1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(4-hydroxybut-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-carboxyprop-1-yl) aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-carboxyprop-1-yl) aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3dioxolane, E-(4S )-0-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(3-ethoxycarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(N"-ethoxycarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(N"-methylaminocarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N'-methyl-N'-(N"-methylaminocarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane, anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N'-methyl-N'-(3-aminoprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy) phenyl)]-1,2,3-trimethoxypropane, anti-(1S, 2R)- 1-[(5-fluoro-3-(4-(N'-methyl-N'-(4-hydroxybut-1-ylaminocarbonyl-N-methylamino) benzyloxy)phenyl)]- 1,2,3-trimethoxypropane, anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N'-methyl-N'-(3-carboxyprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3-trimethoxypropane, anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N'-methyl-N'-(3-ethoxycarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3trimethoxypropane, and anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N'-methyl-N'-(N "-methylaminocarbonylprop-1-yl)aminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3-trimethoxypropane. Preferred compounds of the present invention have the structure defined above wherein R 1 is alkyl of one to four carbon atoms; R 2 is selected from (a) alkenyl of one to four carbon atoms, (b) ##STR12## and (c) ##STR13## where W is oxygen, R 9 is alkyl of one to four carbon atoms, and R 10 is alkyl of one to four carbon atoms; L 1 is a valence bond; L 2 is a valence bond or alkyl of one to four carbon atoms; L 3 is selected from (a) ##STR14## where R 13 is hydrogen and R 14 is alkyl of one to four carbon atoms, and (b) ##STR15## where R 15 is hydrogen or alkyl of one to four carbon atoms; R 7 and R 8 are alkyl of one to four carbon atoms, or taken together define a group of formula ##STR16## where R 16 and R 17 are independently selected from hydrogen and alkyl of one to four carbon atoms; Y is selected from oxygen and >S(O)n where n=0, 1, or 2; and R 3 , R 4 , R 5 , and R 6 are as defined above. Particularly preferred compounds of the present invention have the structure defined immediately above wherein L 2 is a valence bond and Y is S. Examples include: E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3dioxolane, E-(4S )-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl) -1,3-dioxolane, and E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. The most preferred compounds of the present invention are: Z-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, E-(4S )-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-13-dioxolane, E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, E-(4R)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13-dioxolane, anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3-trimethoxypropane, and anti-(1S, 2R)-1-[(5-fluoro-3-{4-(N-acetyl-N-methylamino)-benzyloxy)phenyl)]-1,2,3-trimethoxypropane. Certain compounds of this invention may exist in either cis or trans or E or Z isomers with respect to the oxime geometry and in addition to stereoisomeric forms by virtue of the presence of one or more chiral centers. The present invention contemplates all such geometric and stereoisomers, including R- and S-enantiomers, diastereomers, and cis/trans or E/Z mixtures thereof as falling within the scope of the invention. If a particular enantiomer is desired, it may be prepared by asymmetric synthesis or by derivatization with a chiral auxiliary and the resulting diastereomeric mixture is separated and the auxiliary group cleaved to provide the pure desired enantiomers. Lipoxygenase Inhibition Determination Inhibition of leukotriene biosynthesis was evaluated in an assay, involving calcium ionophore-induced LTB 4 biosynthesis expressed human whole blood. Human heparinized whole blood was preincubated with test compounds or vehicle for 15 min at 37° C. followed by calcium ionophore A23187 challenge (final concentration of 8.3 μM) and the reaction terminated after 30 min by adding two volumes of methanol containing prostaglandin B 2 as an internal recovery standard. The methanol extract was analyzed for LTB 4 using a commercially available radioimmunoassay. The compounds of this invention inhibit leukotriene biosynthesis as illustrated in Table 1. TABLE 1______________________________________In Vitro Inhibitory Potencies of Compoundsof this Invention Against 5-Lipoxygenase fromStimulated LTB.sub.4 Formation in Human Whole BloodExample IC.sub.50 (10.sup.-6 M)______________________________________1 100% @ 0.100 μM2 82% @ 0.20 μM3 99% @ 6.25 μM(Z oxime)3 0.05(E oxime)4 100% @ 6.25 μM5 100% @ 0.78 μM14 49% @ 0.10 μM15 42% @ 0.78 μM______________________________________ Pharmaceutical Compositions The present invention also provides pharmaceutical compositions which comprise compounds of the present invention formulated together with one or more non-toxic pharmaceutically acceptable carriers. The pharmaceutical compositions may be specially formulated for oral administration in solid or liquid form, for parenteral injection, or for rectal administration. The pharmaceutical compositions of this invention can be administered to s humans and other animals orally, rectally, parenterally, intracisternally, intravaginally, intraperitoneally, topically (as by powders, ointments, or drops), bucally, or as an oral or nasal spray. The term "parenteral" administration as used herein refers to modes of administration which include intravenous, intramuscular, intraperitoneal, intrasternal, subcutaneous and intraarticular injection and infusion. Pharmaceutical compositions of this invention for parenteral injection comprise pharmaceutically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions as well as sterile powders for reconstitution into sterile injectable solutions or dispersions just prior to use. Examples of suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (such as glycerol, propylene glycol, polyethylene glycol, and the like), and suitable mixtures thereof, vegetable oils (such as olive oil), and injectable organic esters such as ethyl oleate. Proper fluidity can be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants. These compositions may also contain adjuvants such as preservatives, wetting agents, emulsifying agents, and dispersing agents. Prevention of the action of microorganisms may be ensured by the inclusion of various antibacterial and antifungal agents, for example, paraben, chlorobutanol, phenol sorbic acid, and the like. It may also be desirable to include isotonic agents such as sugars, sodium chloride, and the like. Prolonged absorption of the injectable pharmaceutical form may be brought about by the inclusion of agents which delay absorption such as aluminum monostearate and gelatin. In some cases, in order to prolong the effect of the drug, it is desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its s rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle. Injectable depot forms are made by forming microencapsule matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides) Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues. The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use. Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carder such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents. Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes. The active compounds can also be in micro-encapsulated form, if appropriate, with one or more of the above-mentioned excipients. Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethyl as formamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents. Suspensions, in addition to the active compounds, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar, and tragacanth, and mixtures thereof. Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable nonirritating excipients or carders such as cocoa butter, polyethylene glycol or a suppository wax which are solid at room temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound. Compounds of the present invention can also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multi-lamellar hydrated liquid crystals that are dispersed in an aqueous medium. Any nontoxic, physiologically acceptable and metabolizable lipid capable of forming liposomes can be used. The present compositions in liposome form can contain, in addition to a compound of the present invention, stabilizers, preservatives, excipients, and the like. The preferred lipids are the phospholipids and the phosphatidyl cholines (lecithins), both natural and synthetic. Methods to form liposomes are known in the art. See, for example, Prescott, Ed., Methods in Cell Biology, Volume XIV, Academic Press, New York, N.Y. (1976), p. 33 et seq. Dosage forms for topical administration of a compound of this invention include powders, sprays, ointments and inhalants. The active compound is mixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives, buffers, or propellants which may be required. Opthalmic formulations, eye ointments, powders and solutions are also contemplated as being within the scope of this invention. Actual dosage levels of active ingredients in the pharmaceutical compositions of this invention may be varied so as to obtain an amount of the active compound(s) that is effective to achieve the desired therapeutic response for a particular patient, compositions, and mode of administration. The selected dosage level will depend upon the activity of the particular compound, the route of administration, the severity of the condition being treated, and the condition and prior medical history of the patient being treated. However, it is within the skill of the art to start doses of the compound at levels lower than required for to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved. Generally dosage levels of about 1 to about 50, more preferably of about 5 to about 20 mg of active compound per kilogram of body weight per day are as administered orally to a mammalian patient. If desired, the effective daily dose may be divided into multiple doses for purposes of administration, e.g. two to four separate doses per day. Preparation of the Compounds of the Invention The compounds of this invention may be prepared by a variety of synthetic routes. Representative procedures are outlined as follows. It should be understood that L 1 , L 2 , R 1 , R 2 , R 3 , R 4 , R 7 , R 13 , R 14 , R 15 , and R 16 as used herein, correspond to the groups identified above. The preparation of trialkoxypropane derivatives is shown in Scheme 1. Aryl bromide 1, prepared according to the method described in EPA 385 679, is metallated using, for example, n-butyllithium, in an organic solvent such as THF. Addition of 2,2-dimethyl-1,3-dioxolane to the aryllithium provides alcohol 2 which is converted to ether 3 by reaction with NaH and R 13 X, where R 13 is defined above and X is a suitable leaving group such as CI, Br, I, methanesulfonyl, or p-toluenesulfonyl. Hydrolysis of the dioxane by treatment with catalytic p-toluenesulfonic acid in methanol affords diol 4 which is converted to trialkoxy compound 5 by reaction with NaH and R 7 X where R 7 and X are defined above. Catalytic hydrogenolysis over palladium on carbon of 5 affords the intermediate phenol 6. Reaction of 6 with NaH and a compound of formula Ar 1 -L 2 -X, where L 2 , and X are defined above, provides 7, which is a representative compound of the invention. ##STR17## The preparation of dioxolane-containing compounds of the invention is shown in Scheme 2. Diol 4, prepared as shown in Scheme 1, is condensed with carbonyl compound R 15 R 16 CO where R 15 and R 16 are defined above under standard ketalization conditions to provide 8. The desired compound 9.9 is then prepared by hydrogenolysis of 8, followed by alkylation of the resulting phenol with Ar 1 -L 2 -X as described in Scheme 1. ##STR18## The preparation of oxime-containing compounds of the invention is shown in Scheme 3. Alcohol 2, prepared as in Scheme 1, is oxidized to ketone 10, for example using Swern oxidation conditions (Swern, D., Manusco, A. J., and Huang, S. L., J. Org. Chem., 1978, 43, 2480). Reaction of 10 with HNOR 14 , where R 14 is defined above affords oxime 11. Hydrolysis 11 as described in Scheme 1 provides key intermediate 12, which is converted to the desired trialkoxypropane 16 or dioxolane 15 as outlined in Schemes 1 and 2 respectively. ##STR19## The preparation of the preferred compounds of the invention is outlined in Scheme 4. 3-(p-nitrobenzenethioxy)bromobenzene 17 was prepared by coupling of m-bromobenzenethiol and p-nitrobromobenzene. Reduction of 17, for example with potassium borohydride and CuCl, gives amine 18 which is formylated according to the procedure of Krishnamurthy (Tetrahedron Lett. 1982, 23, 3315) to provide N-formyl compound 19. Treatment of 19 with NaH and R 1 X where R 1 is alkyl and X is Br, Cl, or I, followed by hydrolysis with aqueous NaOH provides alkylamine 20. Reaction of 20 with NaH and allyl bromide provides 21, which is converted to the desired compound 22 as outlined in Schemes 1-3. Compounds in which R 2 is R 9 R 10 NCO are prepared by treatment of 23 with a suitable base such as lithium hexamethyldisylazide and carbamoyl chloride R 9 R 10 NCOCl. ##STR20## The preparation of the compounds of this invention where R 10 is haloalkyl or aminoalkyl is shown in Scheme 5. Amine 23, prepared as in Scheme 4, is treated with the desired haloalkylisocyanate to form haloalkyl derivative 25. Conversion of 25 to azide 26, for example with sodium azide, and alkylation with sodium hydride and R 9 X as described above provides 27, which is reduced to the desired aminoalkyl compound 28 by treatment with 1,3-propanedithiol. ##STR21## The preparation of the compounds of this invention where R 10 is hydroxyalkyl, carboxyalkyl, (alkoxycarbonyl)alkyl, or (alkylaminocarbonyl)alkyl, is shown in Scheme 6. Amine 23, prepared as in Scheme 4, is treated with an alkoxycarbonylalkylisocyanate to provide the alkoxycarbonylalkyl derivative 29, which is alkylated by treatment with NaH and R9X as described above to form 30. Hydrolysis of ester 30 provides carboxyalkyl derivative 31. Reduction of 30 with lithium borohydride or 31 with BH 3 provides hydroxyalkyl compound 32. The (alkylaminocarbonyl)alkyl derivatives 33 are prepared from ester 30, or acid 31 by standard synthetic methods. ##STR22## The preparation of the arylpropynyl-, arylpropenyl-, and arylpropyl-aryl ether compounds of the invention is shown in Scheme 6. 4-iodoaniline is converted to urea 34 by acylation with dimethylcarbamyl chloride, followed by alkylation with NaH and R 1 X. Coupling of 34 with propargyl alcohol provides propynol 35 which is converted to chloride 36 by treatment with phosphorus trichloride. The desired arylpropynyl-aryl ether 37 is then prepared as described in Schemes 1-3. Reduction of alkynol 35 with Red-Al (sodium bis(2-methoxyethoxy)aluminum hydride) provides trans allylic alcohol 38, which is converted to the desired compound 39 as described above. Catalytic hydrogenation of 39, for example with palladium on carbon, provides saturated compound 40. ##STR23## The foregoing may be better understood by the following Examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention. EXAMPLE 1 Preparation of E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane. Step 1: (4R, 1'R)- and(4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)hydroxymethyll-1,3-dioxolane. A flame-dried flask was charged with 3-(napth-2-ylmethoxy)-5-fluorobromobenzene (0.86 g. 2.6 mmol), prepared according to the method of EPA 385 679, a stir bar, and freshly dried tetrahydrofuran (THF, 23 mL). The resulting solution was cooled to -78 ° C. under a nitrogen atmosphere and n-butyllithium (2.5M in hexanes, 1.04 mL, 2.6 mmol) was added slowly in a dropwise fashion via syringe. After stirring for 10 minutes at -78 ° C. a THF solution (6 mL) of (R)-(+)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde (0.34 g, 2.6 mmol), prepared as described in Jackson, Synthetic Commun. 1988, 18(4), 337-341) was added. The resulting solution was stirred for 30 minutes at -78 ° C., and the cooling bath was removed. The reaction was stirred for 1 hour and then quenched with excess saturated aqueous NH 4 Cl. The mixture was partitioned between saturated aqueous NH 4 Cl and ethyl acetate. The organic layer was washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to provide a cloudy oil which was purified by chromatography on silica gel (20% ether:hexanes) to give the less polar anti-(4R, 1'S) alcohol (0.193 g, 20%), a mixture of both isomers (0.233 g, 23%), and the more polar syn-(4R, 1'R) alcohol (0.149 g, 15%). Step 2: (4R)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2ylmethoxy)phenyl)carbonyl. methyl]- 1,3-dioxolane. Following the Swern oxidation procedure (Swern, D.; Manusco, A. J.; Huang, S. L.,J. Org. Chem. 1978, 43, 2480) a mixture of (4R, 1'R)- and (4R, 1'S)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2ylmethoxy)phenyl)hydroxymethyl]-1,3-dioxolane (0.55 mg, 1.44 mmol), prepared as in step 1, was oxidized to the corresponding ketone (350 mg, 66%) after chromatography on silica gel. Step 3: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)oximinomethyl]-1,3-dioxolane. To a solution of (4R)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)carbonylmethyl]-1,3-dioxolane (50 mg, 0.132 mmol), prepared as in step 2, in ethanol (0.5 mL) were added sequentially 0-methyl-hydroxylamine hydrochloride (55 mg, 0.66 mmol) and pyridine (53 ]μL, 0.66 mmol). The resulting solution was stirred at 40° C. for 1 hour and the volatiles were removed in vacuo. The resulting residue was partitioned between ethyl acetate and water. The aqueous layer was separated and extracted twice with ethyl acetate. The combined organic layers were were washed once with saturated aqueous NH 4 Cl, twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo. The isomers were separated by chromatography on silica gel (1.0% ethyl acetate/hexanes) to give in the order of elution the pure Z-oxime isomer (14.5 rag, 27%), a mixture of both isomers (24.3 mg, 45%), and the pure E-oxime isomer (6.5 mg, 12%). Z-isomer: 1 H NMR (300 MHz, CDCl 3 ) δ 7.83-7.90 (4H, m), 7.47-7.54 (3H, m), 7.06 (1H, br s), 6.93 (1H, ddd, J=10, 1.5, 2.5 Hz), 6.73 (1H, dr, J=10, 3, 3 Hz), 5.46 (1H, t, J=7 Hz), 5.22 (2H, s), 4.43 (1H, dd, J=7.5, 9 Hz), 3.98 (3H, s), 3.83 (1H, dd, J=9, 7.5 Hz), 1.37 (3H, s), 1.28 (3H, s). MS m/e 410 (M+H) + , 427 (M+NH 4 ) + . Analysis calc'd for C 24 H 24 NO 4 F: C, 70.40; H, 5.91; N, 3.42. Found: C, 70.30; H, 5.95; as N, 3.43. E-isomer: 1H NMR (300 MHz, CDCl 3 ) 6 7.83 -7.90 (4H, m), 7.47-7.54 (3H, m), 6.84 (1H, br s), 6.70-6.78 (2H, m), 5.22 (2H, s), 4.85 (1H, t; J=7.5 Hz), 4.12 (1H, dd, J=7.5, 9 Hz), 3.91 (1H, dd, J=9, 7.5 Hz), 3.84 (3H, s), 1.38 (3H, s), 1.29 (3H, s). MS m/e 410 (M+H) + , 427 (M+NH 4 ) + . Analysis calc'd for C 24 H 24 NO 4 F: C, 70.40; H, 5.91; N, 3.42. Found: C, 70.30; H, 5.95; N, 3.43. Step 4: E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl]-1,3-dioxolane. A flask was charged with 10% Pd/C (130 mg) and a solution in ethanol (4.5 mL) of E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)oximinomethyl]-1,3-dioxolane (450 mg, 1.1 mmol), prepared as in step 3, was added. The reaction mixture was evacuated and flushed with hydrogen (3 cycles) and maintained under 1 atmosphere of hydrogen at ambient temperature for 1 hour. The reaction mixture was flushed with nitrogen and filtered through a pad of celite. The filter cake was rinsed thoroughly with ethanol and the combined flitrates were concentrated in vacuo. Purification by chromatography on silica gel (10% ethyl acetate/hexanes) gave E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl]-1,3-dioxolane as a colorless oil (259 mg, 86%). Step 5: methyl 4-(N-methylaminocarbonyl)aminobenzoate. A solution of methyl 4-aminobenzoate (15 g, 99 mmol), and methyl isocyanate (11.8 mL, 200 mmol) in toluene (400 mL) was heated at 100° C. under N2 for 3 hours during which time a precipitate formed slowly. Additional methyl isocyanate (11.8 mL, 200 mmol) was added and heating was continued for 2 hours. The reaction mixture was cooled to 0° C. and filtered. The precipitate was washed with ether and vacuum-dried to give methyl 4-(N-methylaminocarbonyl)aminobenzoate as a colorless solid (17.5 g, 85%). Step 6: methyl 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzoate. To a 0° C. suspension of NaH (80% oil dispersion, 3.60 g, 120 mmol) in THF (200 mL) under N 2 was added a solution of methyl 4-(N-methylaminocarbonyl)aminobenzoate (10.0 g, 48 mmol), prepared as in step 5, in THF (40 mL). The reaction mixture was stirred at 0° C. until gas evolution ceased, then the cold bath was removed and stirring was continued for 1.5 hours. A solution of iodomethane (6.6 mL, 106 mmol) in DMF (24 mL) was added and the reaction mixture was stirred for 72 hours at ambient temperature. NaH (2.0 g) , and as iodomethane (5.0 mL) were then added and the reaction mixture was stirred for an additional 2 hours. The reaction mixture was poured slowly into ice-water and the organics were stripped off in vacuo. The aqueous solution was extracted with ethyl acetate (10 x). The combined organic layers were dried over MgSO 4 , filtered, and concentrated. Pure methyl 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzoate (6.62 g, 58%) was obtained as a colorless oil which crystallized on standing after chromatography on silica gel (40%, then 50% ethyl acetate / hexanes). mp 71°-73° C. Step 7: 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyl alcohol. To a 0° C. solution of methyl 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzoate (1.50 g, 6.35 mmol), prepared as in step 6, in THF (11.4 mL) was added lithium triethylborohydride (1.0 M solution in THF, 14 mmol). The reaction mixture was stirred for 1 hour. Water (3.0 mL) and H 2 O 2 (30% aqueous solution, 5.0 mL) were added cautiously and the reaction mixture was stirred at 45° C. for 20 min. Aqueous HCL (6 M, 8.0 mL) was added and the reaction mixture was stirred at reflux for 14 hours. The reaction mixture was cooled to ambient temperature and poured into ethyl acetate. The aqueous phase was extracted three times with ethyl acetate. The combined organic layers were dried over MgSO 4 , filtered, and concentrated in vacuo. 4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyl alcohol (797 mg, 61%) was isolated as a colorless solid by chromatography on silica gel (ethyl acetate). mp 65°-66° C. Step 8: 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride. To a stirred solution at -23° C. under N 2 of 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl alcohol (77.0 rag, 0.37 mmol), prepared as in step 7, in dry CH 2 C12 (3.7 mL) was added triethylamine (67.0 μL, 0.48 mmol), and mcthanesulfonyl chloride (34.0μL, 0.44 mmol). The reaction mixture was stirred at ambient temperature until TLC indicated complete reaction (˜5 hours). The resultant solution was poured into ethyl acetate and the organic phase was washed (2 X, water; 2 X, brine), dried (MgSO 4 ), filtered and concentrated in vacuo. Purification by flash chromatography on silica gel (70% ethyl acetate / hexane) provided 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride (56.0 mg, 67.0%) as a colorless oil which crystallized on standing at -25 ° C. mp 38.5°-39 ° C. 1H NMR (300 MHz, CDCl 3 ) δ 7.34 (2H, d, J=8.5 Hz), 7.04 (2H, d, J=8.5 Hz), 4.57 (2H, s), 3.22 (3H, s), 2.71 (6H, s). MS m/e 227 (M+H) + , 244 (M+NH 4 ) + . Step 9: E-(4S)-O-Methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl-1,3: dioxolane. To a flask containing E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl]-1.3-dioxolane (160 mg, 0.59 mmol) in dry DMF (10 mL) was added sodium hydride (80% oil dispersion, 20 mg, 0.65 mmol). After gas evolution ceased, 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride (134 mg, 0.59 mmol) was added in a single portion. The reaction was stirred for 3 hours and partitioned between ethyl acetate and saturated aqueous ammonium chloride. The aqueous layer was drawn off and extracted with ethyl acetate (3x, 10 mL). The combined organic layers were washed with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give an orange oil. Purification by chromatography on silica gel (30% ethyl acetate:hexanes) provided pure E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximino -1.3-dioxolane (170 mg, 62%). 1H NMR (300 MHz, CDCI3) δ7.37 (2H, d, J=9 Hz), 7.39 (2H, d, J=9 Hz), 6.81 (1H, br s), 6.67-6.77 (2H, m), 4.98 (2H, s), 4.86 (1H, t, J=7.5 Hz), 4.13 (1H dd, J=8.5, 7.5 Hz), 3.92 (1H, dd, J=8.5, 7.5 Hz), 3.87 (3H, s), 3.23 (3H, s), 2.71 (6H, s), 1.39 (3H, s), 1.32 (3H, s). MS m/e 460 (M+H) + , 477 (M+NH 4 ). Analysis calc'd for C 24 H 30 N 3 O 5 F: C, 62.73; H, 6.58; N, 9.14. Found: C, 62.56; H, 6.66; N, 9.08. EXAMPLE 2 Preparation of E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane. Step 1: 4,-(N-acetyl-N-methylamino)benzoic acid. To a solution of N-methyl-4-aminobenzoic acid (2.0 g, 13.2 mmol) dissolved in anhydrous pyridine (13.2 mL) was added acetic anhydride (1.4 mL, 14.5 mmol). The reaction was stirred at ambient temperature until TLC indicated complete reaction (˜22 hours). The resulting solution was poured into ethyl acetate and the organic phase was washed (3 X, 10% HCl; 1 X, water; 1 X, brine), dried (MgSO 4 ), filtered, and concentrated in vacuo to provide the corresponding amide as a colorless solid. Recrystallization (ethyl acetate / hexane) afforded pure 4-(N-acetyl-N-methylamino)benzoic acid (2.15 g, 84.0%). 1 H NMR (300 MHz, CDCl 3 ) δ8.18 (2H, br d, J=8.5 Hz), 7.33 (2H, br d, J=8.5 Hz), 3.33 (3H, s), 2.0 (3H, br s) MS m/e 194 (M+H) + , 211 (M+NH 4 ) + . Step 2. Preparation of 4-(N-acetyl-N-methylamino)benzyl alcohol. An oven dried flask, under nitrogen flow, was charged with a stir bar, 4-(N-acetyl-N-methylamino)benzoic acid (1.0 g, 5.18 mmol), prepared as in step 1, anhydrous DME (10.3 mL), and anhydrous DMF (3.0 mL). The resulting solution was cooled to -20 ° C., and 4-methylmorpholine (0.60 mL, 5.4 mmol) and isobutyl chloroformate (0.70 mL, 5.4 mmol) were added sequentially via syringes. The reaction mixture was stirred under N 2 at -20° C. for 1 h. The resulting yellow mixture was filtered and the precipitate washed with DME (2 X, ˜1 mL). The combined filtrate and washings were cooled to 0° C. and a solution of sodium borohydride (800 mg, 21.1 mmol) in water (2.0 mL) was added dropwise. The reaction was stirred at 0° C. for 15 min. and quenched with saturated aqueous ammonium chloride. The resulting mixture was partitioned between ethyl acetate and brine. The combined organic layers were dried (MgSO 4 ), filtered and concentrated in vacuo to give an oil. Purification by flash chromatography on silica gel (90% ethyl acetate / hexane) provided the corresponding alcohol as a colorless oil which solidified on standing. Recrystallization from hexane provided 4-(N-acetyl-N-methylamino)benzyl alcohol as a colorless solid (543.0 mg, 58.5%). 1 H NMR (300 MHz, CDCl 3 ) δ7.45 (2H, d, J =8.5 Hz), 7.18 (2H, d, J=8.5 Hz), 4.75 (2H, s), 3.27 (3H, s), 1.90 (3H, br MS m/e 180 (M+H) + , 197 (M+NH 4 ) + . Step 3. Preparation of 4-(N-acetyl-N-methylamino)benzyl bromide. To a solution of 4-(N-acetyl-N-methylamino)benzyl alcohol (543.0 mg, 3.0 mmol), prepared as in step 2, dissolved. in dry CH 2 Cl 2 (11.5 mL) was added dropwise 1M PBr 3 in CH 2 Cl 2 (3.6 mL, 3.6 mmol) at 0° C. The reaction was stirred at ambient temperature until TLC indicated complete reaction (˜5 hours). The resulting solution was partitioned between ethyl acetate and brine. The combined organic layers were decolorized with charcoal, dried (MgSO 4 ), filtered through celite and concentrated in vacuo. Purification by flash chromatography on silica gel (40% ethyl acetate / hexane) provided 4-(N-acetyl-N-methylamino)benzyl bromide as a colorless solid (595 mg, 81.0%). 1 H NMR (300 MHz, CDCl 3 ) δ7.46 (2H, d, J=8.5 Hz), 7.18 (2H, d, J=8.5 Hz), 4.50 (2H, s), 3.27 (3H, s), 1.88 (3H, br s). MS m/e 242 (M+H) + , 259/261 (M+NH 4 ) + . Analysis calc'd for C 10 H 12 NOBr: C, 49.61; H, 5.00; N, 5.79. Found: C, 49.35; H, 4.97; N, 5.65. Step 4: E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-13-dioxolane. The desired compound was prepared according to the method of Example 1, step 9, except substituting 4-(N-acetyl-N-methylamino)benzyl bromide, prepared as in step 3, for 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride. Chromatography on silica gel (50% ethyl acetate:hexanes) provided E-(4R)-O-methyl-2,2-dimethyl -4- [(5-fluoro-3-(4-(N-acetyl-N-methylamino)benzyloxy)phenyl )oximinomethyl]-1,3-dioxolane. 1 H NMR (300 MHz, CDCl 3 ) δ7.48 (2H, d, J=9 Hz), 7.22 (2H, d, J=9 Hz), 6.82 (1H, br s), 6.76 (1H, br d, J=9.5 Hz), 6.72 (1H, dr, J=10.5, 3 Hz), 5.06 (2H, s), 4.87 (1H, tt, J=7 Hz), 4.13 (1H, dd, J=7.5, 8 Hz), 3.92 (1H, dd, J=7.5, 9 Hz), 3.87 (3H, s), 3.28 (3H, br s), 1.89 (3H, br s), 1.39 (3H; s), 1.32 (3H, s). MS m/e 43 1 (M+H) + , 448 (M+NH 4 ) + . Analysis calc'd for C 23 H 27 N 2 O 5 F(0.25 H 2 O): C, 63.51; H, 6.37; N, 6.44. Found: C, 63.39; H, 6.37; N, 6.34. EXAMPLE 3 Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl) -1,3-dioxolane. Step 1:3 -(p-nitrobenzenethioxy)bromobenzene. A 500 mL round bottomed flask equipped with a magnetic stirbar was charged with sodium hydride (3.78 g of a 60% oil dispersion, 95 mmol), and freshly dried THF (200 mL) under a stream of nitrogen. To the stirred suspension was added t-butanol (8 mL). When hydrogen gas evolution ceased, m-bromobenzenethiol (12.0 g, 63 mmol) was via syringe over 5 rain and the resulting solution was stirred for 10 min. To this solution was added in a single portion p-nitrobromobenzene (10.7 g, 52.9 mmol). The solution was stirred at room temperature for 45 min and sodium hydride (0.5 g of a 60% oil dispersion, 12.5 mmol) was added. After 30 min m-bromobenzenethiol (1.0 mL, 9.7 mmol) was added and the reaction was judged to be complete 30 min later by tlc. The reaction mixture was partitioned between saturated aqueous ammonium chloride and ethyl acetate. The layers were separated and the aqueous layer was extracted with ethyl acetate (3 x, 100 mL). The combined organic extracts were washed (1x, 15% aqueous sodium hydroxide; 2x, brine), dried (Na 2 SO 4 ), filtered and concentrated in vacuo to to ˜400 mL. Decolorizing carbon was added to the organic extracts and the solution was filtered through a celite pad as and concentrated in vacuo to give the unpurified product as an orange solid (19.4 g). The solid was taken up in ether and treated with decolorizing carbon, filtered through celitc, and the volatiles removed in vacuo. Two recrystallizations from ether/hexanes provided pure 3-(p-nitrobenzenethioxy)bromobenzene. Step 2: 3-(p-aminobenzenethioxy)bromobenzene. To a THF (15 mL) solution of 3-(p-nitrobenzenethioxy)bromobenzene (2.0 g, 6.4 mmol), prepared as in step 1, was added methanol (50 mL) and CuC 1 (0.89 g, 99%, 9.0 mmol). The solution was cooled to ˜10° C. in an icebath and solid potassium borohydride (1.13 g, 21 mmol) was added in small portions while maintaining the reaction temperature below 20° C. After complete addition of potassium borohydride the icebath was removed. The reaction was judged to be complete after 20 min and was quenched by adding water (40mL) while maintaining the reaction temperature under 20° C. The quenched reaction mixture was filtered through celite and partitioned between ether and water. After separating the layers the aqueous layer was extracted three times with ether. The combined organic layers were washed twice with brine and concentrated to 1/2 the original volume. The solution was treated with decolorizing carbon while drying over MgSO 4 , filtered through a celite pad, and concentrated in vacuo to give 3-(p-aminobenzenethioxy)bromobenzene (1.81 g, 101%) as a waxy red solid which was carried on without further purification. Step 3: 3-(N-formyl-p-aminobenzenethioxy)bromobenzene. 3-(p-aminobenzenethioxy) bromobenzene (1.13 g, 4.1 mmol), prepared as in step 2 was formylated according to the procedure of Krishnamurthy (Tetrahedron Lett. 1982, 23, 33 15). The reaction mixture was partitioned between ether and saturated aqueous sodium bicarbonate. The layers were separated and the aqueous layer was extracted three times with ether. The combined organic layers were washed once with brine, treated with decolorizing carbon and MgSO 4 , filtered through a celite pad, and concentrated in vacuo to give 3-(N-formyl-p-aminobenzenethioxy)bromobenzene as a light brown oil (1.31 g, 104%) which was carried on without further purification. Step 4: 3-(N-methyl-p-aminobenzenethioxy)bromobenzene. A flask equipped with a magnetic stirbar was charged under a stream of nitrogen with freshly dried THF (100 mL) and sodium hydride (2.75 g, 60% oil dispersion, 69 mmol). A solution in dry THF of 3-(N-formyl-p-amino-benzene thioxy)bromobenzene (17.63 g, 57.4 mmol), prepared as in step 3, was added slowly. After foaming ceased dry DMF (100 mL) and methyl iodide (5.75 mL; plug filtered through neutral alumina) were added. The reaction was stirred at ambient temperature for 1.5 hours when the reaction was judged to be complete by tlc. The reaction was quenched with excess saturated aqueous ammonium chloride and partitioned between water and ether. The layers were separated and the aqueous layer was extracted with three times with ether. The combined organic layers were washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give the alkylated compound (24.74 g). The resulting residue was dissolved in ethanol (230 mL), 15% aqueous sodium hydroxide was added, and the resulting mixture was heated at 60° C. for 0.5 hours and at 80° C. for 0.5 hours. The reaction mixture was cooled in an icebath and neutralized to pH˜7 with 10% aqueous HCl. The resulting mixture was partitioned between ether and water. The layers were separated and the aqueous layer was extracted with three times with ether. The combined organic layers were washed twice with saturated aqueous NH 4 C 1 , twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give 15.95 g of crude product. Purification by chromatography on silica gel (5% ethyl acetate:hexanes) provided pure 3-(N-methyl-p-aminobenzenethioxy)bromobenzene (12.21 g, 73%). Step 5: 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene. A flask was charged with potassium hydride (0.3 g, 35% oil dispersion, 2.62 mmol) and dry THF (1.5 mL) under a stream of nitrogen. A solution of 3-(N-methyl-p-aminobenzenethioxy)bromobenzene (0.50 g, 1.71 mmol), prepared as in step 4, in dry THF was added via syringe. When gas evolution ceased, allyl bromide (0.38 mL, 4.27 mmol, passed through a neutral alumina pad before addition) was added in a single portion, followed by dry DMF (3.4 mL). After 15 min the reaction was quenched with isopropanol and partitioned between saturated aqueous NH 4 C 1 and ethyl acetate. The layers were separated and the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to give 0.91 g of crude product. Purification by chromatography on silica gel (5% ethyl acetate:hexanes) provided pure 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene (0.43 g, 75%). Step 6: (4R, 1'R) and (4R, 1'S)-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)hydroxymethyl]-1,3-dioxolane. The desired compound was prepared according to the method of Example 1, step 1, except substituting 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene for 3-(napth-2-ylmethoxy)-5-fluoro-bromobenzene. The mixture of alcohols was not separated during purification. Step 7:E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds were prepared according to the method of Example 1, steps 2 and 3, except substituting 124R, 1'R) and (4R, 1'S)-4-[(3-(4-(N-allyl-N-methyl phenylthioxyl)phenyl)hydroxymethyl]-1,3-dioxolane (2.02 g, 5.25 mmol), prepared as in step 6, for (4R, 1'R)- and (4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)hydroxymethyl]-1,3-dioxolane. The oxime isomers (871 mg, 46%) were isolated by chromatography on silica gel (7% ethyl acetate:hexanes). Z-(4S)-O-Methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, which solidified on standing, was recrystallized from cold ether/ethyl acetate mp 49°-50° C. 1 H NMR (300 MHz, CDCl 3 ) δ7.25-7.43 (4H, m), 7.28 (1H, t, J=8 Hz), 7.08 (1H, br d, J=8 Hz 6.72 (2H, br d, J=6 Hz), 5.84 (1H, octet, J=5.5, 14, 17 Hz), 5.42 (1H, t, J=7.5 Hz), 5.18 (1H, br d, J=14 Hz), 5.16 (1H, br d, J=17 Hz), 4.42 (1H, t, J=7.5 Hz), 3.93-3.96 (5H, m), 3.81 (1H, t, J=7.5 Hz), 2.98 (3H, s), 1.34 (3H, s), 1.23 (3H, s). MS m/e 413 (M+H) + . Analysis calc'd for C 23 H 28 N 2 O 3 S: C, 66.96; H, 6.84; N, 6.79. Found: C, 66.91; H, 6.93; N, 6.79. E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3dioxolane was an oil. 1 H NMR (300 MHz, CDCl 3 ) δ7.36 (2H, d, J=8.5 Hz), 7.22 (1H, d, J=7.5 Hz), 7.17 (1H, br s), 7.09 (1H, br t, J=6.5 Hz), 6.75 (2H, br s) 5.87 (1H, octet, J=5.5, 10, 18 Hz), 5.19 (1H, br d, J=10 Hz), 5.17 (1H, br d, J =18 Hz), 4.82 (1H, t, J=7 Hz), 4.18 (1H, dd, J=7, 8.5 Hz), 3.95 (2H, dr, J=5.5, 1,1 Hz), 3.83-3.85 (4H, m), 2.98 (3H, s), 1.37 (3H, s), 1.26 (3H, s). MS m/e 413 (M+H) + . Analysis calc'd for C 23 H 28 N 2 O 3 S: C, 66.96; H, 6.84; N, 6.79. Found: C, 66.98; H, 6.82; N, 6.71. EXAMPLE 4 Preparation of Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. Step 1:Z-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-N-methylaminophenylthioxy)phenyl)oximinomethyl]-1,3-dioxolane. To an ethanol (22 mL) solution of Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (268 mg, 0.65 mmol), prepared as in Example 3, was added tris(triphenylphosphine)ruthenium(II) chloride (120 mg, 0.13 mmol). The resulting solution was heated at 80° C. for 30 min, another portion of the ruthenium catalyst (120 mg, 0.13 mmol) was added, and the reaction was stirred until it cooled to ambient temperature. The volatiles were removed in vacuo and the residue was partitioned between water and ethyl acetate. After separating the layers the aqueous layer was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO 4 , filtered and concentrated in vacuo. The resulting oil was purified by chromatography on silica gel (30% ethyl actetate:hexanes) to provide Z-(4S )-O-methyl-2,2-dimethyl-4- [(3-(4- N-methylaminophenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (227 mg, 94%). Step 2: Z-(4S)-O-Methyl-2,2-dimethyl-4-[(3-(4-(N',N' -dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. To a solution of Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-N-methylaminophenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (100 mg, 0.27 mmol), prepared as in step 1, in dry THF at -78° C. was added lithium hexamethyldisilazide (LiHMDS, 403 μL, 1M solution in THF, 0.40 mmol ). After stirring in the cold for 10 min dimethylcarbamoyl chloride (37μL, 0.40 mmol) was added via syringe in a single portion. The cooling bath was removed and the reaction mixture was stirred for 30 min at ambient temperature. The reaction was quenched by adding excess water and partitioning the resulting mixture between saturated aqueous NH 4 Cl and ethyl acetate. After separating the layers, the aqueous layer was extracted 3 times with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO 4 , filtered and concentrated in vacuo. The resulting oil was purified by chromatography on silica gel (50% ethyl actetate:hexanes) to provide Z-(4S)-O-methyl-4-[(3-{4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]- 1,3-dioxolane as an oil which crystallized upon dissolving in ethyl acetate and cooling (58 mg, 44%). mp 102°-103° C. 1 H NMR (300 MHz, CDCl 3 ) δ7.52 (1H, m), 7.37-7.43 (1H, m), 7.26-7.33 (4H, m), 6.98 (2H, d, J=8 Hz), 5.44 (1H, t, J=7.5 Hz), 4.44 (1H, dd, J=7.5, 8.5 Hz), 3.95 (3H, s), 3.82 (1H, dd, J=7.5, 8.5 Hz), 3.21 (3H, s), 2.72 (6H, s 1.34 (3H, s), 1.23 (3H, s). MS m/e 444 (M+H) + , 461 (M+NH 4 ) + . Analysis calc'd for C 23 H 29 N 3 O 4 S: C, 62.28; H, 6.59; N, 9.47. Found: C, 62.18; H, 6.71; N, 9.23. EXAMPLE 5 Preparation of E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N': dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3: dioxolane. The desired compound was prepared as described in Example 4 except substituting E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (290 mg, 0.70 mmol) for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. Purification by chromatography on silica gel (50% ethyl acetate:hexanes) provided E-(4S)-O-methyl2,2-dimethyl-4- [(3-(4-(N', N'-dimethylaminocarbonyl-No methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane (121 rag, 58%) as an oil. 1H NMR (300 MHz, CDCl 3 ) t) 7.22-7.38 (6H, m), 6.98 (2H, d, J=8 Hz), 4.84 (1H, t, J=7.5 Hz), 4.13 (1H, dd, J=7.5, 8.5 Hz), 3.87 (1H, dd, J=7.5, 8. Hz), 3.84 (3H, s), 3.22 (3H, s), 2.72 (6H, s), 1.38 (3H, s), 1.25 (3H, s). MS m/e 444 (M+H) + , 46 1 (M+NH 4 ) + . Analysis calc'd for C 23 H 29 N 3 O 4 S: C, 62.28; H, 6.59; N, 9.47. Found: C, 61.91; H, 6.68; N, 9.15. EXAMPLE 6 Preparation of Z- and E-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)oximinomethyl]-1,3-dioxolane. Step 1: (S) -(-)2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde. The desired compound was prepared as described in Jackson, Synthetic Commun. 1988, 18(4), 337-341), except starting with L-(S)-glyceraldehyde, prepared as described by Hubschwerlen, C. Synthesis, 1986, 962-964, instead of D-(R)-glyceraldehyde. Step2: Z-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinoethyl[-1,3-dioxolane. The desired compounds are prepared according to the method of Example 1, steps 1-3, except substituting (S)-(-)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde, prepared as in step 1, for (R)-(-)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde, and substituting 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene, prepared as in Example 3, step 5, for 3-(napth-2-ylmethoxy)-5-fluoro-bromobenzene. EXAMPLE 7 Preparation of Z- and E-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl}phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared according to the method of Example 4, except substituting Z- and E-(4R)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 6, for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. EXAMPLE 8 Preparation of E-(4R)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)oximinomethyl]-1,3dioxolane. The desired compound was prepared according to the method of Example 1, except substituting (S)-(-)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde, prepared as in Example 6, step 1, for (R)-(-)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde. 1 H NMR (300 MHz, CDCl 3 ) δ7.37 (2H, d, J=9 Hz), 7.39 (2H, d, J=9 Hz), 6.81 (1H, br s), 6.67-6.77 (2H, m), 4.98 (2H, s), 4.86 (1H, t, J=7.5 Hz), 4.13 (2H, dd, J=8.5, 7.5 Hz), 3.92 (1H, dd, J=8.5, 7.5 Hz), 3.87 (3H, s), 3.23 (3H, s), 2.71 (6H, s), 1.39 (3H, s), 1.32 (3H, s). MS m/e 460 (M+H) + , 477 (M+NH 4 ). Analysis calc'd for C 24 H.sub. 30 N 3 O 5 F: C, 62.73; H, 6.58; N, 9.14. Found: C, 65.28; H, 5.83; N, 6.12 . EXAMPLE 9 Preparation of E- and Z-(4S)-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared according to the method of Example 1, steps 2 and 3, except substituting 3-(N-allyl-N-methyl-p-aminobenzenethioxy)bromobenzene, prepared as in Example 3, step 5, for 5-fluoro-3-(napth-2-ylmethoxy)bromobenzene, and substituting hydroxylamine hydrochloride for O-methylhydroxylamine hydrochloride. EXAMPLE 10 Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfinyl)phenyl)oximino -1,3-dioxolane. The desired compounds are prepared by oxidation of Z- and E-(4S)-O-methyl-4-2,2-dimethyl-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 3, with sodium metaperiodate as described in EPA 409 413 (Example 7). EXAMPLE 11 Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylsulfonyl)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared by oxidation of Z- and E-(4S)-O-methyl4-2,2-dimethyl- [(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 3, with potassium peroxymonosulfate as described in EPA 409 413 (Example 14). EXAMPLE 12 Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N',N'-dimethylaminothiocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]1,3-dioxolane. The desired compound is prepared by treatment of Z- and E-(4S)-O-methyl-4-2,2-dimethyl- [(3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Examples 4 and 5, with Lawesson's Reagent ([2,4-bis-(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide) according to the method of Katah, A., Kashima, C., and Omote, Y., Heterocycles, 1982, 19 (12), 2283. EXAMPLE 13 Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-(5-fluoro-3-(4-((N',N'-dimethylaminocarbonyl)-N-methylamino)benzylthioxy)phenyl)oximinomethyl]-1,3-dioxolane. Step 1: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(benzylthioxy)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared according to the method of Example 1, steps 1-3, except substituting 5-fluoro-3-benzylthiobromobenzene, prepared as described in EPA 420 511 (Example 4), for 3-(napth-2-ylmethyloxy)-5-fluorobromobenzene. Step 2: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-1(5-fluoro-3-mercaptophenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared by debenzylation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(benzylthioxy)phenyl)oximinomethyl]-1,3-dioxolane, prepared in step 1, with benzoyl peroxide as described in EPA 420 511 (Example 4). Step 3: Z- and E-(4R)-O-methyl-2,2-dimethyl-4-(5-fluoro-3-(4-((N',N'-dimethylaminocarbonyl)-N-methylamino)benzylthioxy)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared according to the method of Example 1, step 9, except substituting Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-mercaptophenyl)oximinomethyl -1,3-dioxolane, prepared as in step 2, for E-(4S)-O-methyl-2,2-dimethyl-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl]-1,3-dioxolane. EXAMPLE 14 Preparation of anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino) 1-1,2,3-trimethoxypropane. Step 1: (4R, 1'-R)- and (4R, 1'S):2,2-dimethyl-4,2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)hydroxymethyl]-1,3-dioxolane. A flame-dried flask was charged with 3-(napth-2-ylmethyloxy)-5-fluorobromobenzene (0.86 g. 2.6 mmol), prepared according to the method of EPA 385 679, a stir bar, and freshly dried tetrahydrofuran (THF, 23 mL). The resulting solution was cooled to -78° C. under a nitrogen atmosphere andn-butyllithium (2.5M in hexanes, 1.04 mL, 2.6 mmol) was added slowly in a dropwise fashion via syringe. After stirring for 10 minutes at -78° C. a THF solution (6 mL) of (R)-(+)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde (0.34 g, 2.6 mmol), prepared as described in Jackson, Synthetic Commun. 1988, 18(4), 337-341) was added. The resulting solution was stirred for 30 minutes at -78° C., and the cooling bath was removed. The reaction was stirred for 1 hour and then quenched with excess saturated aqueous NH 4 Cl. The mixture was partitioned between saturated aqueous NH 4 Cl and ethyl acetate. The organic layer was washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to provide a cloudy oil which was purified by chromatography on silica gel (20% ether:hexanes) to give the less polar anti-(4R, 1'S) alcohol (0.193 g, 20%), a mixture of both isomers (0.233 g, 23%), and the more polar syn-(4R, I'R) alcohol (0.149 g, 15%). Step 2: syn-(4R, 1'R)- and anti-(4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)methyloxymethyl[-1,3-dioxolane. Each alcohol isomer prepared in step 1 was independently methylated following the procedure described for the anti-isomer. A flask was charged with anhydrous DMF (5 mL) and(4R, 1'S)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)hydroxymethyl]-1,3-dioxolane (0.185 g, 0.484 mmol). Sodium hydride (80% oil dispersion, 14.5 mg, 0.484 mmol) was added in a single portion and the reaction mixture was stirred at ambient temperature until gas evolution ceased (5-10 minutes). To the resulting solution was added methyl iodide (103 μL, 0.726 mmol; freshly filtered through a neutral alumina pad) and the reaction mixture was stirred at ambient temperature for 0.5 hours. The reaction was quenched by adding water and was then partitioned between water and ethyl acetate. The organic layer was washed twice with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to provide a yellow oil which was purified by chromatography on silica gel (50% ether:hexanes) to give anti-(4R, 1'S)-2,2 -dimethyl-4-2,2-dimethyl[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)methyloxymethyl ]-1,3-dioxolane (0.176 g, 92%) as a colorless oil. 1 H NMR (300 MHz, CDCl 3 ) 6 7.83-7.90 (4H, m), 7.47-7.55 (3H, m), 6.79 (1H, br s), 6.63-6.72 (2H, m), 5.22 (2H, s), ca. 4.12 (1H, m), 4.0-4.05 (3H, m), 3.35 (3H, s), 1.41 (3H, s), 1.29 (3H, s). MS m/e 397 (M+H) + , 414 (M+NH 4 ) + . Analysis calc'd for C 24 H 25 O 4 F(0.1 H 2 O): C, 72.38; H, 6.38. Found: C, 72.14; H, 6.05. Methylation of (4R, 1'R)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2as ylmethyloxy)phenyl)hydroxymethyl]-1,3-dioxolane as described above gave syn(4R, 1'R)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)methyloxymethyl] -1,3-dioxolane. 1 H NMR (300 MHz, CDCl 3 ) δ7.83-7.90 (4H, m), 7.47-7.55 (3H, m), 6.78 (1H, br s), 6.63-6.72 (2H, m), 5.22 (2H, s), 4.24 (1H, quartet, J=7.5 Hz), 4.08 (1 H, d, J=7.5 Hz), 3.60 (1H, dd, J=8.5, 7.5 Hz), 3.52 (1H, dd, J=8.0, 7.5 Hz), 3.25 (3H, s), 1.42 (3H, s), 1.37 (3H, s). MS m/e 397 (M+H) + , 414 (M+NH 4 ) + . Analysis calc'd for C 24 H 25 O 4 F(0.75 H 2 O): C, 70.31; H, 6.15. Found: C, 70.31; H, 5.94. Step 3: anti-(1S, 2R)-2,3-dihydroxy-1-methyloxymethyl-1-(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)propane. To a solution of anti-(4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2ylmethyloxy)phenyl)methyloxymethyl]-1,3-dioxolane (0.145 g, 0.37 mmol), prepared as in step 2, dissolved in methanol (10 mL) was added catalytic paratoluenesulfonic acid monohydrate (25 mg, 0.13 mmol). The reaction was stirred at ambient temperature until TLC indicated complete reaction (˜18 hours). The is volatiles were removed in vacuo and the resulting solution was partitioned between ethyl acetate and saturated aqueous NaHCO 3 . The organic phase was washed twice with brine, dried over MgSO 4 , filtered and concentrated in vacuo to provide anti-(1 S, 2R) 2,3-dihydroxy-1-methyloxymethyl-1 -(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)propane as a colorless solid (120 mg, 92%) which was carried on without further purification. Step 4: anti-(1S, 2R)-1-[(5-fluoro-3-(napth-2-ylmethyloxy)-1,2,3-trimethoxypropane. To a solution in dry THF (5 mL) of anti-(1S, 2R)-2,3-dihydroxy-1 -[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)]-1-methoxypropane (50 mg, 0.14 mmol), prepared as in Example 2, step 1, was added sodium hydride (8.4 mg; 80% oil dispersion; 0.28 mmol) was. After gas evolution ceased, methyl iodide (17 μL; 0.28 mmol) was added and the reaction was stirred at ambient temperature for 15 hours. Excess sodium hydride was quenched by careful addition of water. The reaction was partitioned between water and ethyl acetate. The aqueous layer was extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over MgSO 4 , filtered, and concentrated in vacuo to provide an orange oil. Purification by slica gel chromatography (ethyl acetate/hexanes) provided pure anti-(1 S, 2R)-1-[(5-fluoro-3-((napth-2-yl)methoxy)-phenyl) ]-1,2,3-trimethoxypropane (40 mg, 74% ). 1l H NMR (300 MHz, CDCl 3 ) δ 7.83-7.90 (4H, m), 7.47-7.55 (3H, m), 6.82 (1H, br s), 6.65-6.72 (2H, m), 5.22 (2H, s), 4.21 (1H, d, J=6 Hz), 3.47-3.53 (2H, m), 3.34-3.42 (1H, m), 3.34 (3H, s), 3.27 (3H, s), 3.25 (3H, s). MS m/e 402 (M+NH 4 ) + . Analysis calc'd for C 23 H 25 O 4 F: C, 71.86; H, 6.55. Found: C, 71.61; H, 6.52. Step 5: anti-(1S, 2R)-1-[(5-fluoro-3-hydroxyphenyl)]-1,2,3-trimethoxypropane. The desired compound was prepared according to the method of Example 1, step 4, except substituting anti-(IS, 2R)-1-[(5-fluoro-3-((napth-2-yl)methoxy)phenyl)]-1,2,3-trimethoxypropane, prepared as in step 4, for E-(4S)-O-methyl-2,2dimethyl -4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethoxy)phenyl)oximinomethyl ]-1,3-dioxolane. Step 6: anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)-benzyloxy)phenyl)]-1,2,3-trimethoxypropane. The desired compound was prepared according to the method of Example 1, step 9, except substituting anti-(1S, 2R)-1-[(5-fluoro-3-hydroxyphenyl)]-1,2,3-trimethoxypropane, prepared as in step 5, for E-(4S)-O-methyl-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-hydroxyphen-1-yl)oximinomethyl ]-1,3-dioxolane. Purification by chromatography on silica gel (50% ethyl acetate:hexanes) provided anti-(1S, 2R)-1-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzyloxy)phenyl)]-1,2,3-trimethoxypropane. 1 H NMR (300 MHz, CDCl 3 ) δ7.48 (2H, d, J=9 Hz), 7.07 (2H, d, J=9 Hz), 6.87 (1H, br s), 6.69 (1H, br d, J=9.5 Hz), 6.62 (1H, dr, J=10.5, 3 Hz), 5.01 (2H, s), 4.20 (1H, d, J =6 Hz), 3.48-3.52 (2H, m), 3.37-3.42 (1H, m), 3.37 (3H, s), 3.27 (3H, s) (3H, s), 3.22 (3H, s). MS m/e 435 (M+H) + , 452 (M+NH 4 ). Analysis calc'd for C 23 H 31 N 2 O 5 F: C, 63.57; H, 7.19; N, 6.44. Found: C, 63.41; H, 7.28; N, 6.28. EXAMPLE 15 Preparation of anti-(1S, 2R)-1-[(5-fluoro-3-{4-(N-acetyl-N-methylamino): benzyloxy)phenyl)]-1,2,3-trimethoxypropane. The desired compound (yellow oil, 154 mg, 91%), was prepared according to the method of Example 2, step 4, except substituting anti-(1S, 2R)-1-[(5-fluoro-3-hydroxyphenyl)]-1,2,3-trimethoxypropane, prepared as in Example 8, step 5, for E-(4S)-O-methyl-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-hydroxyphenyl)oximinomethyl]-1,3-dioxolane. 1H NMR (300 MHz, CDCl 3 ) δ7.49 (2H, d, J=9 Hz), 7.22 (2H, d, J=9 Hz), 6.79 (1H, br s), 6.72 (1H, br d, J=9.5 Hz), 6.64 (1H, dr, J=10.5, 3 Hz), 5.07 (2H, s); 4.21 (1H, d, J=6 Hz), 3.49-3.53 (2 3.37-3.42 (1H, m), 3.37 (3H, s), 3.28 (6H, s), 3.26 (3H, s), 1.89 (3H, br s) m/e 406 (M+H) + , 423 (M+NH 4 ) + . Analysis calc'd for C 22 H 28 NO 5 F: C, 65.17; H, 6.96; N, 3.45. Found: C, 65.17; H, 7.09; N, 3.27. EXAMPLE 16 Preparation of anti-(1S, 2R)-1-[3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]: 1,2,3 -trimethoxypropane. The desired compound is prepared according to the method of Example 14, steps 2-4, except substituting (4R, 1'R) and (4R, 1'S)-2,2-dimethyl-4-[(3-(4-(N allyl-N-methylamino)phenylthioxyl)phenyl)hydroxymethyl]-1,3-dioxolane, prepared as in Example 3, step 6, for (4R, 1'S)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)hydroxymethyl]-1,3-dioxolane. EXAMPLE 17 Preparation of anti-(1S, 2R)-1-[3-(4-(N',N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl) phenyl]-1,2,3-trimethoxypropane. The desired compound is prepared according to the method of Example 4, except substituting anti-(1S, 2R)-1-[3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, prepared as in Example 15, for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. EXAMPLE 18 Preparation of anti-(1S, 2R)-1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)benzylthioxyl)phenyl]-1,2,3-trimethoxypropane. Step 1: anti-(1S, 2R)-1-[(5-fluoro-3-(benzylthioxy)phenyl-1,2,3: trimethoxypropane. The desired compound is prepared according to the method of Example 14, steps 1-4, except substituting 5-fluoro-3-benzylthiobromobenzene, prepared as described in EPA 420 511 (Example 4), for 3-(napth-2-ylmethyloxy)-5-fluorobromobenzene. Step 2: anti-(1S, 2R)-1-[(5-fluoro-3-mercaptophenyl) ]-1,2,3-trimethoxypropane. The desired compound is prepared according to the method of Example 13, step 2, except substituting anti-(1S, 2R)-1-[(5-fluoro-3-(benzylthioxy)phenyl)]- 1,2,3-trimethoxypropane, prepared as in step 1, for Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(benzylthioxy)phenyl)oximinomethyl ]-1,3-dioxolane. Step 3: anti-(1S, 2R)-1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino) benzylthioxyl)phenyl]-1,2,3-trimethoxypropane. The desired compound is prepared according to the method of Example 14, step 6, except substituting anti-(1S, 2R)-1-[(5-fluoro-3-mercaptophenyl)]-1,2,3trimethoxypropane prepared as in step 2, for anti-(1S, 2R)-1-[(5-fluoro-3-hydroxyphenyl) ]-1,2,3-trimethoxypropane. EXAMPLE 19 Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-(N', N'-dimethylaminocarbonyl-N-methylamino)methyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane. Step 1: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4: bromomethyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared according to the method of Example 1, step 9, except substituting α,α'-dibromo-p-xylene for 4-(N',N'-dimethylaminocarbonyl-N-methylamino)benzyl chloride. Step 2: Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-(N', N'dimethylaminocarbonylamino)methyl)benzyloxy)phenyl)oximinomethyl ]-1,3-dioxolane. The desired compounds are prepared by reaction of a solution of 1,1-dimethylurea in DMF with NaH and Z- and E-(4S)-O-methyl-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(4-bromomethyl)benzyloxy)phenyl)oximinomethyl ]-1,3-dioxolane, which is prepared as described in step 1. Step 3: Z- and E-(4S)-O-methyl.-.2.2-dimethyl-4-[(5-fluoro-3-((4-(N', N': a0 dimethylaminocarbonyl-N-methylamino)methyl)benzyloxy)phenyl)oximinomethyl]: 1,3-dioxolane. The desired compounds are prepared according to the method of Example 14, step 2, except substituting Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4(N', N'-dimethylaminocarbonylamino)methyl)benzyloxy)phenyl )oximinomethyl ]-1,3-dioxolane, prepared as in step 2, for (4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethyloxy) phenyl)hydroxymethyl]-1,3-dioxolane. EXAMPLE 20 Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-((4-imidazolidin-2-on-1-ylmethyl)benzyloxy)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared according to the method of Example 19, step 2, except substituting 2-imidazolidinone for 1,1-dimethylurea. EXAMPLE 21 Preparation of Z- and E-(IS)-O-methyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]]-1,2-dimethoxyethane. The desired compounds are prepared according to the method of Example 14, steps 3 and 4, except substituting Z- and E-(4S)-O-Methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 3, for anti-(4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(napth-2-ylmethyloxy)phenyl)m -1,3-dioxolane. EXAMPLE 22 Preparation of Z- and E-(1S)-O-methyl-4-[(3(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,2-dimethoxyethane. The desired compounds are prepared according to the method of Example 4, except substituting Z- and E-(1S)-O-methyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]]-1,2-dimethoxyethane, prepared as in Example 21, for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. EXAMPLE 23 Preparation of Z- and E-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-acetyl-N-methylamino) phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared according to the method of Example 1, step 9, except substituting acetyl chloride for N, N-dimethylcarbamoyl chloride. EXAMPLE 24 Preparation of E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl) 1,3-dioxolane. The desired compounds are prepared according to the method of Example 3, except substituting 5-fluoro-3-bromobenzenethiol, prepared according to the method described in EPA 420 511 (Example 4), for m-bromobenzenethiol. EXAMPLE 25 Preparation of E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3: dioxolane. The desired compounds are prepared according to the method of Example 4, except substituting Z-(4S)-O-methyl-2,2-dimethyl-4-[(5- fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 24, for Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-(N-allyl-N-methylamino)phenyl thioxyl )phenyl)oximinomethyl ]-1,3-dioxolane. EXAMPLE 26 Preparation of anti-(1S, 2R)-1- [5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane. The desired compound is prepared according to the method of Example 16, except substituting (4R, 1'R) and (4R, 1'S)-2,2-dimethyl-4-[(5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl)hydroxymethyl]-1,3-dioxolane, prepared as in Example 24, for (4R, 1'S)-2,2-dimethyl-4-2,2-dimethyl-[(5-fluoro-3-(napth-2-ylmethyloxy -1,3-dioxolane. EXAMPLE 27 Preparation of anti-(1 S, 2R)-1-[5-fluoro-3-(4-(N', N'-dimethylaminocarbonyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane. The desired compound is prepared according to the method of Example 17, except substituting anti-(1S, 2R)-1-[5-fluoro-3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, prepared as in Example 26, for anti-(1S, 2R)-1-[3-(4-(N-allyl-N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane. EXAMPLE 28 Preparation of E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-methylpiperazin-1-ylcarbonyl)-N-methylamino)phenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. The desired compounds are prepared by treatment of E- and Z-(4S)-O-methyl-2,2-dimethyl-4-[(3-(4-N-methylaminophenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane, prepared as in Example 4, step 1, with triphosgene and 4-methylpiperazine according to the method of Eckert, H., and Forster, B., Angew. Chem. lnt. Ed., 1987, 26(9), 894-895. Example 29 Preparation of anti-(1S, 2R)-1-[3-(4-(N-(4- methylpiperazin-1-ylcarbonyl)-N-methylamino) phenylthioxyl)phenyl]-1,2,3-trimethoxypropane. The desired compound is prepared according to the method of Example 28, except substituting anti-(1S, 2R)-1-[3-(4-(N-methylamino)phenylthioxyl)phenyl]-1,2,3-trimethoxypropane, prepared as in Example 16, for E- and Z-(4S)-O-methyl2,2-dimethyl-4-[(3-(4-N-methylaminophenylthioxyl)phenyl)oximinomethyl]-1,3-dioxolane. The compounds represented in Table 2 are prepared as described in Schemes 4 and 5 and Example 28. TABLE 2______________________________________Novel 1,3-dioxolane inhibitors of 5-Lipoxygenase. ##STR24##Example R.sup.5 R.sup.1 R.sup.9 R.sup.10______________________________________30 H Me Me ##STR25##31 F Me Me ##STR26##32 H Me Me ##STR27##33 F Me Me ##STR28##34 H Me Me ##STR29##35 F Me Me ##STR30##36 H Me Me ##STR31##37 F Me Me ##STR32##38 H Me Me ##STR33##39 F Me Me ##STR34##40 H Me Me ##STR35##41 F Me Me ##STR36##42 H Me ##STR37##43 F Me ##STR38##44 H Me ##STR39##45 F Me ##STR40##46 H Me ##STR41##47 F Me ##STR42##______________________________________ The compounds represented in Table 3 are prepared as described in Schemes 4 and 5 and Example 29. TABLE 3______________________________________Novel Trimethoxypropane inhibitors of 5-Lipoxygenase. ##STR43##Example R.sup.5 R.sup.1 R.sup.9 R.sup.10______________________________________48 H Me Me ##STR44##49 F Me Me ##STR45##50 H Me Me ##STR46##51 F Me Me ##STR47##52 H Me Me ##STR48##53 F Me Me ##STR49##54 H Me Me ##STR50##55 F Me Me ##STR51##56 H Me Me ##STR52##57 F Me Me ##STR53##58 H Me Me ##STR54##59 F Me Me ##STR55##60 H Me ##STR56##61 F Me ##STR57##62 H Me ##STR58##63 F Me ##STR59##64 H Me ##STR60##65 F Me ##STR61##______________________________________

Compounds of the structure ##STR1## where R 1 is alkyl of one to four carbon atoms and R 2 is selected from (a) alkenyl of one to four carbon atoms, (b) ##STR2## (c) ##STR3## and (d) ##STR4## are potent inhibitors of lipoxygenase enzymes and thus inhibit the biosynthesis of leukotrienes. These compounds are useful in the treatment or amelioration of allergic and inflammatory disease states.

RELATED APPLICATIONS [0001] This application is a continuation-in-part application Ser. No. 09/851,685, filed May 8, 2001 and of Ser. No. 09/653,646, filed Sep. 1, 2000, which is a continuation application of Ser. No. 09/226,322, filed Jan. 6, 1999, now U.S. Pat. No. 6,190,018, issued Feb. 20, 2001. BACKGROUND OF INVENTION [0002] 1. Field of Invention [0003] This invention is directed generally to flashlights, and more particularly to a miniature flashlight using a light emitting diode (“LED”) as a light source that is useful for law enforcement personnel and civilians alike. [0004] 2. Background of the Invention [0005] Conventional general purpose flashlights are well known in the prior art and have often been used by law enforcement personnel in the execution of their duties and by them and civilians in emergency situations. Flashlights are used for a wide variety of purposes. For example, they are often used during traffic stops to illuminate the interior of a stopped vehicle or to complete a police report in the dark. They are also used to facilitate searches of poorly lit areas and may be used to illuminate dark alleys or stairwells. Also, they are used to check or adjust equipment when positioned in a darkened area or at night time, and can be used to send coded signals to one another. Generally, small incandescent lightbulbs and LED flashlights were not dependable when needed. [0006] However, the size and weight of conventional flashlights add to the inconvenience and reduce the mobility of law enforcement personnel required to carry such flashlights along with the other law enforcement equipment. Sometimes the flashlight is purposefully or inadvertently left behind. This presents a problem when the need for a flashlight arises and the flashlight is not located on the person, or otherwise readily available In addition to the use of flashlights by law enforcement personnel, civilians also use flashlights for a number of different reasons. Besides the traditional, home uses of flashlights, smaller flashlights are used in today's society for various security purposes. For example, when going to one's car late in the evening, it is not uncommon for an individual, especially a female, to carry a small flashlight with her. She can use the flashlight to assist in getting the key in the keyhole in the dark. Additionally, she can use the flashlight to check whether someone is hiding in the back seat before getting into the car. Even small conventional flashlights, however, are generally cumbersome and inconvenient to carry for this purpose. [0007] Thus, there is a need for a compact, lightweight flashlight that may easily be carried on the person of a law enforcement officer or civilian and conveniently attached to one's keychain or carried on one's clothing to help insure that the flashlight remains in possession of the user and can be quickly and easily retrieved and removed when needed. Description of the Prior Art [0008] Although not having been proven useful to law enforcement personnel, there exists in the prior art a small flashlight known as the Photon Micro Light. The Micro Light consists of two flat, circular 3 volt batteries, a light emitting diode (“LED”) and an outer shell that encloses the batteries and leads of the LED. The Micro Light uses a slide switch or pressure switch that activates the light by moving the leads of the LED into direct engagement with the batteries. The outer shell consists of two hard plastic parts opposite either side of the batteries and may be held together with four threaded screws. [0009] The Micro Light, however, has a number of disadvantages. The Micro Light lacks the durability required for a miniature flashlight. It lacks an internal structure for protecting and securing the batteries and LED. Only the hard plastic outer shell protects the internal components of the flashlight. Thus, little protection is provided for the internal components of the flashlight and the Micro Light may be adversely affected when subjected to shock. [0010] The Micro Light operates by using either a slide switch or pressure switch which upon activation brings both the leads of the LED into direct engagement with the batteries. This results in increased fatigue on the leads of the flashlight and undesirable wear that affects the reliability of the switch. Moreover, because of its external shape and hard plastic outer shell construction, the Micro Light is not suitable for receiving markings or engravings on the outside surfaces thereof, cannot have a medallion installed thereon, have a die struck panel, or disclose using a translucent housing. In many instances it is desirable to color code the exterior of the flashlight, or to provide medallions, die struck panels, engravings, markings, or other indicia on the exterior surface. However, the construction of the Micro Light is not well suited or adapted to allow for any such color coding or desired markings or engravings. SUMMARY OF THE INVENTION [0011] The subject invention is specifically directed to a small, compact LED flashlight useful to both law enforcement personnel and civilians. One embodiment of the invention may include an LED flashlight wherein the LED has first and second leads extending therefrom; a power source; a power source frame enclosing at least a portion of the power source; a power source frame housing containing the power source frame, light source and power source; a switch located adjacent the power source and operable to close a circuit including the light source and the power source; a keyring extension extending from the power source frame, said keyring extension having an opening whereby an article can be attached to the keyring extension, and the keyring extension further includes a keyring lock connected to the power source frame or power source frame housing wherein upon exerting a force against the keyring lock, the keyring lock is opened to permit the article to be attached to the keyring extension. [0012] The power source frame is non-conductive and has a cavity adapted to house the power source. The power source frame may also have a receptacle for receiving and housing a connector end of the light source. The power source frame therefore serves as a fitted compartment for holding in place and protecting the various internal components of the flashlight. The power source frame provides significant protection to the power source and the light source and serves to cushion these elements from the adverse affects of any shock the flashlight might receive. The power source frame housing encases the power source frame, and provides further protection to the internal components of the flashlight, in addition to that provided by the power source frame. The power source frame housing thus serves to provide an additional level of protection to the light source and the power source and enhances the durability of the flashlight. [0013] Another embodiment of the invention may include an LED flashlight wherein the LED has first and second leads extending therefrom; a power source having a first side and a second side, the second side being opposite the first side; a housing enclosing the leads of the LED and the power source, wherein the housing is comprised of translucent material; and a switch operable to close a circuit including the LED and the power source. [0014] Still a further embodiment of the invention may include an LED flashlight wherein the LED has first and second leads extending therefrom; a power source; a housing containing the LED and the power source; the housing includes at least one side cover which is not integral with the housing; the at least one side cover being selected from anodized metal, anodized metal which includes indicia, die struck metal, laser engraved metal, and a side cover having a separate medallion attached thereto; and a switch located adjacent the power source and operable to close a circuit including the light source and the power source. [0015] The LED is preferably an LED that has a high luminous intensity. Manufacturers of LEDs grade the LED according to its quality. The highest quality LEDs are given an “E” grade. The next highest quality is a “D” grade. LEDs with a “D” grade can be equipped with a lens to approximate the quality of an “E” grade LED. LEDs of this quality were initially used in medical applications and are sometimes referred to as having medical grade application. Although the flashlight of the present invention can be used with any conventional LED, in a preferred embodiment, the light source is an “E” grade LED or lensed “D” grade LED. Such a high intensity LED may be obtained from Hiyoshi Electric, Co., Ltd. located in Tokyo, Japan, having Part No. E1L533BL. The high intensity LED herein described has from three to five times the luminous intensity of a conventional LED. The LED preferably emits blue light, although the present invention may be used with any color LED. Blue light helps to preserve a user's night vision compared with conventional flashlights emitting white light. For other applications bluegreen LEDs can be used, for example, in situations where compatibility with night vision equipment is desired. Other colored LEDs can also be used. Red LEDs can be used in applications where the preservation of night vision is desired or for use with pilots and photographers, and even infrared LEDs can be used where certain signalling capabilities are required or for use with equipment that senses infrared light. The LED includes first and second leads extending from a connector end of the LED. The LED leads may be provided with extensions that can be soldered onto the leads of the LED. [0016] The power source may be any battery having sufficient power to energize an LED. The power source is preferably round and has oppositely disposed generally flat sides, sometimes referred to as coin cells. A pair of stacked 3 volt batteries of this type may be used as the power source. Three-volt lithium batteries are preferably used to provide for longer life, and greater shelf life. [0017] The power source frame may be made of nonconductive plastic and preferably has generally flat oppositely disposed first and second sides. The power source frame may be adapted to receive and house a power source, and includes a power source cavity for this purpose. The power source frame also includes a receptacle at a front end to receive and house a connector end of an LED. The leads of the LED are preferably positioned so that one lead extends over the first side of the power source and another lead extends over the second side of the power source. The power source frame protects and secures the internal components of the flashlight. The power source frame also provides resistance to shock and safeguards the light source and power, source within its frame. The power source frame may include a power source cavity cover that serves to further enclose the power source, and may include a bottom support beneath the cavity for further supporting the power source. [0018] A switch element is preferably located on the side opposite of the power source cavity. The side of the power frame opposite the side having the power source cavity may include a counterbore having a terminus in the power source frame that houses a switch element. The counterbore may be included in the power source cavity cover as well. The switch element is preferably a dome plate that is located between one of the leads of the LED and the power source, but out of contact with the power source. The dome plate is sometimes referred to as a tactile dome plate or a snap dome plate. The switch is activated by applying pressure to the dome plate, thereby completing a circuit that includes the leads of the LED and the power source. With this switch arrangement, a switch button is depressed forcing one lead of the LED into contact with the dome plate which in turn contacts the power source. Thus, in this embodiment, one lead of the LED never comes into direct contact with the power source. Once pressure is removed from the button, the contact between the dome plate and power source is broken and the flashlight returns to its normal “off” position. Thus, the switching arrangement reduces the wear on the leads of the LED and increases the overall reliability. [0019] The power source frame may be adapted to receive a weight, which is preferably round and has opposite ends coplanar with the opposite sides of the power source frame. The weight may be press fit into a cavity or tapered hole in the power source frame specifically adapted to receive the weight. The weight provides for a heavier flashlight and improved balance. In addition, the weight provides the flashlight with greater substance and as a result a higher perceived value in the hands of the user. With the additional weight added to the flashlight, the flashlight appears more substantial and of a higher quality than a lighter weight flashlight. [0020] The power source frame housing is preferably of a two piece construction, with each piece disposed on either side of the power source frame. The power source frame housing includes a first housing side disposed about the first side of the power source frame and a second housing side disposed about the second side of the power source frame, the two sides conforming to the periphery of the power source frame. The housing is preferably constructed of plastic. In one embodiment, the housing may be translucent. In this manner, the light from the LED may be dispersed throughout the housing to effectively illuminate the light. In one embodiment, the entire housing may be translucent. It may also be colored to match the color of the LED. For example, a red translucent housing may be used with a red LED, a blue translucent housing may be used with a blue LED, etc. [0021] The power source frame may have a plurality of pegholes located about the periphery of either side thereof. In addition, the first and second housing sides of the power source frame housing may be provided with a plurality of pegs extending from an inner periphery thereof. The pegs are positioned to engage in a mating relationship with the plurality of pegholes located about the periphery of the sides of the power source frame such that the housing sides can be engaged with the power source frame. The mating of the pegs and the pegholes facilitates assembly of the flashlight by allowing the parts to be precisely aligned during their assembly. It has been found that gluing the power source frame housing to the power source frame provides for a suitable adhesion of the parts. Alternately, ultrasonic welding can be used to attach the parts. Unlike the prior art, separate screws are not needed to attach the parts of the flashlight together and thus assembly is facilitated. In this manner, the housing sides may include notches that mate with corresponding notch receptacles on the power source frame. The housing sides may thus be advantageously ultrasonically welded to the power source frame. [0022] The flashlight housing may be provided with at least one separate side cover and preferably be provided with first and second side covers that are positioned between the first and second housing sides of the power source frame housing and with the housing sides sandwiches the power source frame. The side covers preferably lie in parallel planes and may have flat outer surfaces that are capable of receiving engravings or markings. It is often desirable to engrave or imprint the side covers with surface indicia. For example, a company logo or name of a product could be located on either of the side covers. The use of engraving or printing on the side covers can be used for promotional or advertising purposes. In addition, a flashlight bearing certain markings on the side covers could serve as a prize or be used to commemorate an important event. In one embodiment, a die struck medallion could be inset in the side cover. [0023] The side covers can be made of a variety of materials, such as metal, plastic, or other protective materials. The side covers are preferably made of anodized aluminum. Aluminum provides the desired strength to the side covers and is easily anodized aluminum engraved or imprinted. Indicia may be laser engraved, silk screened, inked, pad printed, or marked in any known manner. In the embodiment where the housing is translucent, the side covers may also be made of a translucent plastic material, or they may be made of non-translucent plastic or metal. Thus, a flashlight may be provided with a translucent housing, and translucent side covers, or a translucent housing and opaque side covers. Where both the housing and side covers are translucent, they may of different colors, to present a two, or even three, tone flashlight. Further, the flashlight may include a translucent power source frame as well. Where translucent side covers are used, indicia may be engraved or printed on the inside surface of the side cover. Thus, the side cover protects the indicia from being marred by normal wear and tear, and also by virtue of being translucent, may provide an attractive gloss finish highlighting the indicia. [0024] In another embodiment, the side covers are a die struck, or coined metal, preferably brass, in which physical indicia may be formed in the metal side cover. Most preferably, both sides of a side cover are struck to provide finer detail in the physical indicia, which may include a company logo, name, or other suitable information. [0025] In another embodiment, a side cover can have a medallion therein. One way of doing this is to cut a hole the size of the medallion in the side cover. An appropriate support and single faced adhesive is attached to the inside of the side cover so that the adhesive can be used to attach the medallion too the side cover. [0026] The side covers provide additional protection to the internal components of the flashlight. The sturdy aluminum construction serves to guard the light source and power source from external forces. Moreover, there is an insulated pocket located between the power source frame and the side covers that provides an air cushion that serves to further protect the light source and power source within the power source frame housing. The side covers may be manufactured as separate components of the flashlight from the power source frame housing. Thus, side covers of varying colors may used to assemble flashlights of varying and contrasting colors. For example, flashlights having side covers bearing corporate colors can be easily assembled. Similarly, flashlights having side covers bearing the colors of a favorite team can be provided. For example, a flashlight having a green side cover on one side and a yellow side cover on the other side could be used to represent the colors of the Green Bay Packers. In addition, a Green Bay Packers logo could be included on one or both side covers of the flashlight. [0027] One of the side covers is adapted to receive a switch button that is secured to the side cover. The button may be made of rubber, and is preferably made of Kraton, the trade name of a thermoplastic rubber made by the Shell Oil Company, and located adjacent the power source. When the button is pushed, a circuit including the leads of the LED and the power source is completed. [0028] The power source frame or power source frame housing may be provided with a keyring extension. The keyring extension may directly extend from the housing or power source frame. The keyring extension includes a keyring lock that opens and closes the keyring extension when a force is exerted against the keyring lock. The keyring extension is opened to permit an item such as a keyring to be attached to the keyring extension. The keyring lock is preferably springbiased and may be attached to the power source frame. The keyring lock may pivot about a circular post positioned on the power source frame. Alternatively, the keyring lock may extend from the interior of the housing, or if a power source frame is used, extend from the power source frame. The keyring extension may be easily attached and detached from any number of items, such as the zipper of a coat or backpack, the handle of a purse or briefcase, a beltloop, or any other handle or case. [0029] The flashlight of the present invention is small, compact and easy to operate. The flashlight may easily be carried in the pocket, on the clothing, or on the keychain of law enforcement personnel or civilians. The flashlight may also be quickly and easily retrieved and operated. [0030] In another embodiment of the invention, a magnet may be provided on the flashlight. It may be internal, external, or coextensive with the housing sides or side covers. Preferably, the magnet is internally positioned within the flashlight. It may be positioned within the interior of the housing, or if a power source frame is used may be positioned on the power source frame or within a cavity on the power source frame. An internal magnet allows for indicia to be marked, printed, or engraved on the housing or side covers of the flashlight. When internally positioned, the magnet is protected from chipping or scratching that could occur if the magnet were externally mounted to the flashlight. Moreover, the magnet itself does not scratch the surface to which it may be mounted as the magnet is protected by the housing or side covers. The magnet may be of sufficient strength to allow the flashlight to be mounted to metal objects. In a preferred embodiment using a magnet, the magnet is of sufficient strength to allow the magnet to attach to metal objects even when using side covers that are made of aluminum or other metals. [0031] It will be understood by those of skill in the art that the various aspects of the disclosed embodiments may be used alone or in connection with the other aspects of the disclosed embodiments. For example, the various disclosed keyring extensions may be used with a housing, with a power source frame and power source frame housing together, with or without side covers, with a translucent housing, with a magnet, etc. BRIEF DESCRIPTION OF THE DRAWINGS [0032] Further advantages of the present invention will become apparent to those skilled in the art with the benefit of the following detailed description of the preferred embodiments and upon reference to the accompanying drawings in which: [0033] [0033]FIG. 1 is a perspective view of an embodiment of the flashlight of the present invention. [0034] [0034]FIG. 2 is a side view of the flashlight depicted in FIG. 1. [0035] [0035]FIG. 3 is a side view of a first side of the power source frame. [0036] [0036]FIG. 4 is a side view of a second side of the power source frame opposite the first side. [0037] [0037]FIG. 5 is a side view of a power source consisting of two circular batteries having generally flat sides. [0038] [0038]FIG. 6 is a side view of alight emitting diode (LED). [0039] [0039]FIG. 7 is a perspective view of a weight. [0040] [0040]FIG. 8 is a side view of a first side of the power source frame including a power source, an LED, a keyring lock, and a spring. [0041] [0041]FIG. 9 is a side view of a second side of the power source frame including an LED, a weight, a keyring lock, a spring, and a switch element. [0042] [0042]FIG. 10 is a cross-sectional view of the power source frame of FIG. 4 taken along plane 11 . [0043] [0043]FIG. 11 is a side view of the exterior of a first side of the power source frame housing. [0044] [0044]FIG. 12 is a side view of the interior of a first side of the power source frame housing. [0045] [0045]FIG. 13 is a side view of the exterior of a second side of the power source frame housing. [0046] [0046]FIG. 14 is a side view of the interior of a second side of the power source frame housing. [0047] [0047]FIG. 15 is a side view of a first side cover. [0048] [0048]FIG. 16 is a side view of a second side cover. [0049] [0049]FIG. 17 is a cross-sectional view of a switch button. [0050] [0050]FIG. 18 is a partial cross-sectional view of the flashlight of FIG. 2 taken along the plane 22 . [0051] [0051]FIG. 19 is a side view of an alternate embodiment of the power source frame. [0052] [0052]FIG. 20 is the opposite side view of the power source frame shown in FIG. 19. [0053] [0053]FIG. 21 is a side view of a power source cavity cover. [0054] [0054]FIG. 22 is an opposite side view of the power source cavity cover shown in FIG. 21. [0055] [0055]FIG. 23 is a perspective view showing the power source cavity cover of FIGS. 21 and 22 used in connection with the power source frame of FIGS. 19 and 20. [0056] [0056]FIG. 24 is atop view of an alternate embodiment of a keyring extension and keyring lock in a connecting relationship. [0057] [0057]FIG. 25 is a top view of the keyring lock of FIG. 24. [0058] [0058]FIG. 26 a is a top view of another alternate embodiment of a keyring lock showing a latch receptacle in dotted lines. [0059] [0059]FIG. 26 b is a bottom view of the keyring lock of FIG. 26 a. [0060] [0060]FIG. 27 is a side view of an alternate embodiment of a power source frame having a cavity for a magnet. [0061] [0061]FIG. 28 is an opposite view of the power source frame of FIG. 27. [0062] [0062]FIG. 29 is a view of the power source frame of FIG. 28 along line 2929 showing a magnet and magnet cavity in dotted lines. [0063] [0063]FIG. 30 is side view of an alternate embodiment of the present invention showing a flashlight with a translucent housing. [0064] [0064]FIG. 31 is an opposite side view of the flashlight of FIG. 30. [0065] [0065]FIG. 32 is a side view of a flashlight having an alternate embodiment of a keyring lock. [0066] [0066]FIG. 33 is a side view of the inside of a die struck cover according to the present invention. [0067] [0067]FIG. 34 is a side view of the outside of the die struck panel of FIG. 33. [0068] [0068]FIG. 35 is a front side view of a cover having a medallion pocket. [0069] [0069]FIG. 36 is FIG. 35 with the medallion in the pocket. [0070] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereof are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0071] A handheld flashlight 10 made in accordance with the principles of the subject invention is depicted in FIGS. 118. As shown in FIG. 2, flashlight 10 preferably includes a side cover 12 , a power source frame housing 14 , a keyring extension 16 , a keyring lock 80 , a switch button 18 , and a light source 20 , extending from a front end of the flashlight. [0072] As depicted in FIGS. 3 and 4, the flashlight of the subject invention further includes a power source frame 22 . The power source frame 22 has oppositely disposed first and second sides 26 , 33 that are generally flat and lie in parallel planes. The power source frame 22 further includes a cavity 24 located on the first side 26 of the power source frame adapted to receive a power source, such as that depicted in FIG. 5. The frame 22 also is provided with a receptacle 28 at a front end 30 thereof, adapted to receive a light source, such as that depicted in FIG. 6. The first side 26 further includes a light source lead channel 29 extending from receptacle 28 to cavity 24 to allow a lead from the light source 20 to extend over cavity 24 . [0073] As depicted in FIG. 3, the power source frame 22 may also include an area 32 adapted to receive a weight. In the embodiment shown in the figures, although not required, the area 32 is a throughhole extending from the first side 22 of the frame to the second side 33 of the frame. Area 32 is tapered at a slight angle to allow the weight to be friction fit within area 32 . The power source frame 22 is further provided with a plurality of pegholes 100 positioned about an outer periphery of the first side 26 of the power source frame. The pegholes 100 are adapted to receive a corresponding set of pegs located on the power source frame housing 14 . The mating of the pegs with the pegholes positions the power source frame housing 14 in proper alignment with the power source frame 22 . The power source frame housing may be ultrasonically welded to the power source frame and/or glued thereto. Thus, there is no need to use threaded screws or other fastening means to hold the frame and the housing together. As a result, the flashlight of the invention is assembled without difficulty. [0074] The power source frame 22 is preferably made of a nonconductive material. Preferably, the power source frame 22 is comprised of Acrylonitrile Butadiene Styrene “ABS” which provides for exceptional durability and toughness. However, any nonconductive material may be employed to construct the frame 22 . Polycarbonate is preferred where the power source frame is translucent. [0075] [0075]FIG. 4 depicts a side view of the second side 33 of power source frame 22 . The second side 33 is provided with a counterbore 34 having a terminus 36 within the power source frame 22 . As shown in FIG. 4, the counterbore 34 is adapted to receive a switch element. The counterbore 34 is preferably located opposite the power source cavity 24 and includes a throughhole 38 extending into cavity 24 that is located on the first side 26 of the power source frame 22 . [0076] As with the first side 26 , the second side 33 preferably includes a light source lead channel 39 extending from receptacle 28 to counterbore 34 to allow a lead from the light source 20 to extend over counterbore 34 . The second side 33 of power source frame 22 may preferably further include a post 40 about which an element of the keyring lock 80 may pivot. Power source frame 22 is also provided with a hub 42 located on a rear side 44 of the frame 20 that is adapted to secure one end of a spring element associated with the keyring lock 80 . As with the first side, the second side 33 of the power source frame may be provided with a plurality of pegholes 110 positioned about its outer periphery to mate with a corresponding set of pegs located on the power source frame housing 14 . [0077] The power source may be any type of battery with sufficient power to energize the light source. As shown in FIG. 5, the power source is preferably one or more circular batteries 50 having generally flat oppositely disposed first and second sides 52 and 54 . In a preferred embodiment, the power source consists of two 3 volt lithium coin cell batteries available from Panasonic bearing the CR2016 marking. These lithium batteries provide for exceptionally long life and durability. In addition, they operate at a low temperature, are leakproof, and vibration resistant. [0078] The light emitting diode light source may be of any type suitable for flashlight use. As shown in FIG. 6, the light emitting diode (“LED”) 60 has first and second leads 62 and 64 extending therefrom. An LED provides great advantages over conventional neon or incandescent light sources, since it requires much less energy, is smaller in size, and more resistant to shock than conventional light sources. It also generates less heat and is more durable than a conventional light source. LEDs are widely available, inexpensive, and can be replaced easily and quickly. In a preferred embodiment, the light source is a high intensity LED having a high luminous intensity emitting blue light. The LED may be a “E” grade LED or a lensed “D” grade LED. [0079] The flashlight may include a weight 70 positioned in area 32 on the power frame housing 14 . The weight provides for a heavier flashlight and for improved balance. It also provides a more substantial feel to the flashlight resulting in a higher perceived value. In a preferred embodiment shown in FIG. 7, the weight 70 has a cylindrical shape and has oppositely disposed first and second faces that are generally flat and lie in parallel planes. The weight 70 preferably has a thickness equal to the thickness of the power source frame 14 . It is preferably made of a dense metal material, preferably stainless steel, and preferably weighs approximately eleven grams. The weight is friction fit or press fit into the corresponding portion of the power source frame housing. [0080] [0080]FIG. 8 is a side view of the first side 26 of the power source frame 22 and depicts power source 50 , LED 60 , keyring lock 80 , and spring 82 . The power source frame 22 preferably has a thickness in the range of approximately 0.15 and 0.25 inch, and preferably 0.018 inches, which is approximately equal to the diameter of LED 60 . As shown in FIG. 8, the LED 60 is positioned in receptacle 28 of the power source frame 22 , and the power source SO is positioned in the cavity 24 of the power source frame 22 . [0081] A first lead 62 of the LED 60 preferably extends over the first side 52 of the power source 50 , which is preferably coplanar with the first side 26 of the power source frame 22 . A lead extension 75 may be attached to the first lead 62 of the LED to extend the length of the lead. The lead extension 75 may be soldered to the first lead 62 . The weight 70 may be positioned within the power source frame 22 , and preferably has a first side 72 that is coplanar with the first side 26 of the power source frame. The weight 70 is preferably press fit or friction fit within the power source frame 22 . [0082] [0082]FIG. 9 is a side view of the second side 33 of the power source frame 22 and depicts LED 60 , weight 70 , keyring lock 80 , spring 82 and switch element 90 . As shown in FIG. 9, the switch element 90 is positioned in the counterbore 34 . The switch element 90 has an outer periphery that contacts the terminus 36 of the counterbore 34 , but is out of contact with the power source 50 . The second lead 64 of LED 60 preferably extends over the switch element 90 . A lead extension may be attached to the second lead 64 , as required. [0083] The switch element 90 is preferably a dome plate 92 or a convex conductor that is positioned in the counterbore 34 , but out of contact with the power source 50 . The dome plate is preferably made of a thin, flexible conductive metal stamping. The lead 64 of the LED contacts the dome plate. To ensure contact, the lead may be taped to the dome plate using, for example, 1.5 millimeter thick tape manufactured by 3M. The dome plate preferably has an engaging element 91 located at the center of its inner surface. [0084] When pressure is applied to the dome plate, the dome plate flexes from a convex to a concave configuration, thereby completing the circuit through the first and second leads of the LED, the engaging element of the dome plate, and the power source. When the pressure is removed, the dome plate returns to its convex position breaking contact with the power source and returning the flashlight to its normal “off” position. In this manner, the lead does not come into direct contact with the power source. It should be noted that a number of alternative push button switch arrangements could be used. For example, the power source frame could include a flexible tongue adjacent to the power source. A lead of the LED could be wrapped around the tongue such that depression of the tongue would bring the lead of the LED into contact with another switch element or into direct contact with the power source to complete the circuit. Alternatively, the lead of the LED could be connected to a flexible tongue having a split metal eyelet adjacent the power source, such that depression of the tongue would complete the circuit. In addition, a number of other mechanical or electrical switches could be utilized, such as slide switches and pressure switches. [0085] As shown in FIG. 9, the keyring lock 80 includes hub 84 operatively connected to a coil spring 82 which is in turn operatively connected to hub 42 of power source frame 22 . It should be understood that many types of springs can be used to bias the keyring lock including coil springs, leaf springs, and U-shaped or plastic springs to name a few. The coil spring may be a separate component, or may be made integral with the power source frame. Spring 82 exerts a force to bias keyring lock 80 to pivot outwardly and about post 40 . The keyring lock 80 is preferably adapted to pivot about post 40 for only a limited distance. Keyring lock 80 further includes a stop 86 that abuts the power source frame 22 to limit the travel of the keyring lock 80 . Preferably, the stop 86 prevents an outer edge 88 of the keyring lock to travel beyond the position where the edge 88 is parallel to an edge 89 of the power source frame. Other keyring locking mechanisms could be used having other forms of springs or resistance to bias the keyring lock. Alternately, the keyring lock could be externally or internally hinged. [0086] The keyring extension 16 and keyring lock 80 of the present invention provide a user with significant versatility in attaching the flashlight to the user's person. For example, the keyring lock 80 may be moved to its open position to allow the flashlight to be easily attached to the zipper of a coat or backpack, the handle of a purse or briefcase, a beltloop, or any other handle or case. In addition, because the keyring lock 80 is normally biased into its closed position, the keyring extension and keyring lock 80 can serve as a clip to easily fasten the flashlight to a shirt pocket or directly to one's clothing. In this manner the shirt pocket or portion of clothing is pinched between an outer end 134 of keyring lock 80 and an outer end 132 of keyring extension 16 . (See FIG. 2). The ability to easily clip the flashlight to one's clothing provides the user with great flexibility in carrying the flashlight on one's person. [0087] [0087]FIG. 10 is a cross-sectional view of the power source frame 22 of FIG. 4 taken along line 11 . Cavity 24 on side 26 preferably has a depth equal to the thickness of the power source 50 and encloses all but an outer surface of the power source. Counterbore 34 on side 33 is located opposite the cavity 24 and has a terminus 36 in the power source frame and throughhole 38 extending therethrough into cavity 24 . The diameter of the counterbore 34 is preferably slightly larger than throughhole 38 . [0088] FIGS. 3 - 10 depict the inner workings of an embodiment of the present invention. However, the invention is not intended to be limited by the particular geometry, locations, and components depicted herein, which are illustrative. [0089] [0089]FIG. 11 is a side view of the exterior of a first housing side 150 of the power source frame housing 14 depicted in FIG. 1. First housing side 150 is adapted to fit over and enclose the first side 26 of the power source frame 22 . [0090] [0090]FIG. 12 is a side view of the interior 156 of first housing side 150 . A plurality of pegs 158 are preferably positioned about an inner periphery of the first housing side 150 . As mentioned above, the pegs 158 are adapted to engage in a mating relationship a corresponding plurality of pegholes 100 located on an outer periphery of the first side 26 of the power source frame 22 . [0091] [0091]FIG. 13 is a side view of an exterior 142 of a second housing side 140 of power source frame housing 14 depicted in FIG. 2. The second housing side 140 is adapted to fit over and enclose the second side 33 of the power source frame 22 . With reference to FIGS. 2 and 13, the exterior 142 includes a keyring extension 16 extending from a rear side 144 thereof. An outer end 132 of keyring extension 16 engages an outer end 134 of keyring lock 80 (as shown in FIG. 2). Alternatively, the keyring extension could be attached to, or integral with, the power source frame, such that the power source frame housing could fit over and enclose the power source frame, except for the keyring extension. In such an alternate embodiment, the second housing side 140 will be identical to the first housing side 150 , shown in FIG. 12. [0092] [0092]FIG. 14 is a side view of an interior 146 of second housing side 140 . A plurality of pegs 148 are preferably positioned about an inner periphery of second housing side 140 . The pegs 148 are adapted to engage in a mating relationship a corresponding plurality of pegholes 110 located on an outer periphery of the second side 33 of the power source frame 22 . [0093] FIGS. 11 - 14 show first and second power source frame housing sides having an opening therein to accommodate the side covers shown in FIGS. 15 and 16. It should be understood, however, that the power source frame housing sides are not limited to accommodating the particular side covers shown in FIGS. 15 and 16. They could be modified to be used with side covers of any geometry. In addition, the housing sides could be made without any openings and used without side covers, such that the power source frame housing sides would completely enclose the power source frame housing. Also, the power source frame housing can be made from any suitable material, and is preferably strong and durable. In a preferred embodiment, the power source frame housing is made of ABS. [0094] [0094]FIGS. 15 and 16 are side views of first and second side covers 160 and 170 . The first and second side covers are preferably positioned between the power source frame 22 and the power source frame housing 14 . First and second side covers 160 and 170 are generally flat and adapted to conform to the outer surfaces of the power source frame 22 such that the side covers preferably lie in parallel planes when positioned between the power source frame 22 and the power source frame housing 14 . The power source frame housing 14 conceals the edges of the side covers when they are positioned between the power source frame 22 and the power source frame housing 14 . The side covers may be of any suitable material including metals, rubbers, and plastics. Preferably the side covers are made of stamped aluminum, preferably anodized 6061 aluminum, and have surfaces suitable for marking or engraving. As noted above, it is often desirable to engrave or imprint the side covers with surface indicia. For example, a company logo or name of a product could be located on either of the side covers. The use of engraving or printing on the side covers can be used for promotional or advertising purposes. In addition, a flashlight bearing certain markings on the side covers could serve as a prize or be used to commemorate an important event. [0095] [0095]FIGS. 35 and 36 illustrate a die struck medallion 161 inset in one of the side covers 162 . A hole 163 is cut in the side cover 162 the size of the medallion 161 . The medallion is shown as cylindrical, but could be any shape, i.e., box, oval, etc. A piece of adhesive 164 is placed inside of the cover so that an adhesive portion 165 faces the outside of the side cover and forms a medallion pocket that permits the medallion to be attached to the side cover. Other mechanisms can be used to attach the medallion to the side cover such as adhering a support piece within the side cover to form the base of the medallion pocket and using an appropriate adhesive to attach the medallion to the side cover. Also, although the medallion is generally metal, it can be any suitable material, i.e., plastic. [0096] A further embodiment is shown in FIGS. 33 and 34 wherein the side cover 166 is die struck metal, i.e., brass, aluminum, wherein the entire side cover 166 is die struck metal, i.e., brass, aluminum having the desired depiction 167 (positive), 167 a (negative) die struck on both sides 168 and 169 for greater detail. This provides a special flashlight for a designated group of people. [0097] The side covers can be made of a variety of materials, such as metal, plastic, or other protective materials. Generally, the side covers are preferably made of anodized aluminum. Aluminum provides the desired strength to the side covers and is easily engraved or imprinted. Indicia may be laser engraved, silk screened, inked, pad printed, or marked in any known manner. [0098] The side covers are on both sides of the power source frame and are held by the power source frame housing. The side covers provide additional protection to the internal components of the flashlight. The sturdy aluminum construction serves to guard the light source and power source from external forces. Moreover, there is an insulated pocket located between the power source frame and the side covers that provides an air cushion that serves to further protect the light source and power source within the power source frame housing. As noted above, in applications where no side covers are used, it is desirable to similarly provide a spaced pocket of air between the power source and the power source frame housing sides to further protect the light source and power source. [0099] As shown in FIG. 15, the second side cover 170 has a hole 172 therethrough adapted to receive a switch button 18 (shown in FIG. 17). When the side cover 170 is positioned between the power source frame 22 and the power source frame housing 14 , hole 172 is located adjacent the switch element 90 . In a preferred embodiment, a thin piece of foam (not shown) is attached to the inner surface of the first side cover 160 . When the flashlight is assembled, the piece of foam serves to compress the first lead 62 of the light source 20 into engagement with power source 50 . The piece of foam also serves to keep the elements of the power source frame 22 tightly enclosed therein, and prevents the internal components from rattling or making noise when in use. [0100] [0100]FIG. 17 is a side view of switch button 18 . Switch button 18 is preferably circular with a circular recess 182 about its periphery. The recess 182 is adapted to secure the switch button 18 to the second side cover 170 . Switch button 18 is preferably made of a resilient material, such as rubber, to allow the button to deform when a force is exerted thereon. In a preferred embodiment, the switch button 18 is made of Kraton, the trade name of a thermoplastic rubber made by the Shell Oil Company. [0101] The switch button 18 further includes an engaging element 184 on an interior surface thereof. When a force is exerted on the button, the engaging element 184 contacts the switch element 90 located in the power source frame 22 . When not engaged, the engaging element 184 is preferably out of contact with the switch element 90 . [0102] [0102]FIG. 18 is a partial cross-sectional view of the flashlight 10 taken along the line 22 of FIG. 2. As shown in FIG. 18, switch button 18 is secured to second side cover 170 , which is positioned between the second housing side 140 of power source frame housing 14 and the power source frame 22 . The engaging element 184 of switch button 18 is preferably positioned adjacent to, but out of contact with, dome plate 92 . An outer periphery 186 of the interior surface of switch button 18 engages an outer periphery of dome plate 92 . As a force is exerted on switch button 18 , the engaging element 184 contacts dome plate 92 . The dome plate 92 then moves in a direction towards the power source 50 until it comes in contact with power source 50 . Once contact is made, a circuit including the leads of the light source 60 , the dome plate 92 , and the power source 50 is completed. [0103] Typically, a flashlight pressure switch makes noise upon its engagement. With the switch button configuration shown herein, the noise created by the dome plate 92 coming in contact with the power source 50 is muffled because the switch button 18 completely encloses the dome plate 92 in the power source frame. Moreover, a raised annular portion 190 of the power source frame partially encloses the outer diameter of the switch button to further enclose the switch button and muffle any sound from the operation of the dome plate. In addition, 1.5 millimeter thick 3M tape may be placed over the lead and dome plate to further muffle the sound of the switch operation. In addition, a small notch is placed in the outer periphery 186 of the interior surface of switch button to allow air to escape through the notch when the button is depressed. [0104] Thus, any noise created is muffled within the switch button 18 . In addition, with the disclosed switch button configuration, when a force is exerted on the dome plate 92 , the user is able to feel the flexure of the dome plate as it moves into contact with the power source 50 . Thus, the switch button configuration provides tactile feedback to the user so that the user is able to feel when the dome plate has come into contact with the power source, and when it is released. This tactile feedback is particularly useful where the flashlight is being operated out of the direct sight of the user, and it is not possible to tell by sight whether the flashlight is on or off. [0105] FIGS. 19 - 23 depict an alternate embodiment of a miniature LED flashlight. As shown in FIGS. 19 and 20, power source frame 222 has oppositely disposed first and second sides 226 , 233 that are generally flat and lie in parallel planes. The power source frame 222 further includes a cavity 224 located on the second side 233 of the power source frame adapted to receive a power source, such as that depicted in FIG. 5. The frame 222 also is provided with a receptacle 228 at a front end 230 thereof, adapted to receive a light source, such as that depicted in FIG. 6. The first side 226 further includes a light source lead channel 229 extending to cavity 224 from receptacle 228 to allow a lead from the light source 220 to extend into cavity 224 . [0106] As depicted in FIG. 20, the power source frame 222 may also include a cavity 232 adapted to receive a weight. In the embodiment shown in the FIGS. 19 and 20, although not required, the power source cavity 224 and the weight cavity 232 have a bottom support 235 positioned on side 226 of the power source frame 222 . The bottom support 235 may be separate from, but is preferably molded integrally with, the power source frame 222 . In addition, the bottom support 235 is shown supporting both the power source cavity 224 and the weight cavity 232 , but also could be limited to support only one or the other. [0107] As shown in FIGS. 21 and 22, a power source cavity cover 240 may be used in connection with the power source frame 222 shown in FIGS. 19 and 20. Power source cavity cover 240 may include pegs 242 that mate in pegholes 244 located on side 233 of power source frame 222 . While such pegs are preferred for proper alignment of the power source cavity cover, any number of known conventions, such as notches, tabs, etc. could be used to properly position and secure the power source cavity cover to the power source frame. The power source cavity cover may be provided with a counterbore 250 having a terminus 252 within the power source cavity cover 240 . As shown in FIGS. 21 and 22, the counterbore 250 is adapted to receive a switch element. Preferably, the switch element is a dome plate, such as that shown as element 92 in. FIG. 18. Of course, other types of flexible switch plates can be suitably used. As shown in FIG. 23, when the power source cavity cover 240 is positioned on the power source frame 222 , the counterbore 250 is preferably located opposite the power source cavity 224 and includes a throughhole 254 extending into cavity 224 that is located on the side 233 of the power source frame 222 . [0108] Referring back to FIGS. 19 and 20, keyring extension 260 extends from power source frame 222 . Keyring extension 260 includes an outer end 262 adapted to engage and connect to an outer end of a keyring lock of the type shown in FIG. 2. In an embodiment shown in FIGS. 24 and 25, the outer end 262 includes a latch 264 that connects to a latch receptacle 266 of the keyring lock 268 . This configuration provides for a positive lock between the outer end 262 of the keyring extension 260 and the keyring lock 268 . The keyring lock may be attached to the interior of the housing, or to the power source frame, using any suitable means of attachment. Preferably, the keyring lock is springbiased and may pivot about a circular post 270 (shown in FIG. 20) in the same manner as shown in FIG. 9. [0109] Alternatively, as shown in FIGS. 26 a and 26 b , the keyring lock may include a receptacle hood 270 that extends over the receptacle 272 , such that the receptacle hood 270 abuts the keyring extension latch 264 , thus preventing an over-extension of the keyring lock 268 . Preferably, the keyring extension is made of ABS, Acrylonitrile Butadiene Styrene, along with the power source frame, although any suitable nonconductive material may be used. The keyring lock is preferably made of a different material, such as nylon, so that it does not become welded to the keyring extension during ultrasonic welding of the power source frame housing sides. [0110] In yet an additional embodiment, shown in FIGS. 27 through 29, a power source frame 322 may include a magnet cavity 370 positioned in bottom support 335 that is adapted to receive a magnet 372 . The magnet attracts both the power source and the weight, if used, to further maintain the placement of the internal components. In the absence of a power source frame, the magnet is preferably positioned within the housing. In a preferred embodiment, the internal magnet 372 is approximately 0.060 inches thick and a half inch in diameter. The magnet is advantageously made of Neodymium alloyed with iron and boron. Most preferably it is a NEP3042NP Neodymium 30 magnet having a Rockwell C scale hardness of 55 available from Bunting Magnets. It is also preferably nickel plated to protect against corrosion. The magnet weighs only 0.003 pounds and has a holding force of three pounds. The use of an internal magnet allows the outer surfaces of the light to maintain their distinctive smooth lines and allows for engravings or other indicia to be placed on the outer surfaces of the light. With this magnet, the light can be attached to refrigerators, toolboxes, or any metal surface. An adhesive steel disc may be provided that may be mounted on any surface in any location to provide a place to attach the light. For example, the steel disc can be mounted to the interior dashboard of a car to provide a resting place for the light and allow for quick retrieval when needed. [0111] A further alternative embodiment is shown in FIGS. 30 and 31. This embodiment includes a translucent housing 400 . The translucent housing may be made of polycarbonate. The flashlight may be constructed using any of the various embodiments disclosed herein. Preferably it includes a power source frame 410 that may also be made of translucent material. In a preferred embodiment, the flashlight includes a translucent power source frame housing 420 having integral side covers that together completely enclose the power source frame. The housing is preferably made of a colored translucent material that may include a matching colored LED 430 . For example, a flashlight having a red colored translucent housing may be used with a red LED. With the translucent housing, the light emitted from the LED is dispersed throughout the housing to provide an illuminated housing. Alternatively, the housing may be provided with separate side covers that are either translucent or opaque. Different colored LEDs may be used with a different colored housing, as well as different colored side covers to provide a rainbow, or kaleidoscope of colors. Or, if the side covers are opaque, the light is only dispersed throughout the translucent portion of the housing. [0112] In an further alternative embodiment, shown in FIG. 32, flashlight 500 may include a keyring extension 510 extending from the housing, or power source frame if used, and may further include a keyring lock 520 extending from the interior of the housing, or the power source frame if used. The keyring lock 520 is preferably springbiased, or most preferably internally hinged, as shown in FIG. 32. The keyring lock 520 includes an outer end 530 that is biased towards and abuts an outer end 540 of keyring extension 510 . The keyring lock operates to allow a keyring to be slipped between the outer end 530 of the keyring lock and the outer end 540 of the keyring extension 510 . This embodiment also may include side covers 550 that are made of santoprene. [0113] While certain features and embodiments of the invention have been described herein, it will be readily understood that the invention encompasses all modifications and enhancements within the scope and spirit of the present invention.

A flashlight having a light-emitting diode light source with first and second leads extending therefrom, a power source, a power source frame enclosing at least a portion of the power source; a housing containing the light source and power source, a switch located adjacent the power source and operable to close a circuit including the light source and the power source, and wherein one or all of the following may be included 1) a keyring extension extending from a power source frame or the housing with the keyring extension having an opening whereby an article can be attached to the keyring extension and includes a keyring lock wherein upon exerting a force against the keyring lock, the keyring lock is opened to permit the article to be attached to the keyring extension; 2) the housing is comprised of translucent material; and 3) the housing includes at least one side cover which is not integral with the housing and the at least one side cover being selected from anodized aluminum, anodized metal, anodized metal which includes indicia, die struck metal, laser engraved metal, and a side cover having a separate medallion attached thereto.

TECHNICAL FIELD [0001] The present invention relates to normal detection method using distance detectors, a normal detection device, and a machining machine provided with a normal detection function. BACKGROUND ART [0002] In machining, it is important to perform machining according to design drawings and according to machining setting. For that purpose, it is required to precisely find out machining positions, machining directions, and machining amounts with respect to workpieces. [0003] For example, in a structure in which a number of component parts are mechanically coupled together by mechanical coupling parts, such as rivets and fasteners, as in an airframe of an aircraft, it is necessary to perform drilling, which allows the mechanical coupling parts to pass through the respective component parts, with precise machining positions, machining directions, and machining amounts. [0004] When a main wing that is one component part of the aircraft, and a skeleton part or the like are mechanically coupled together by a mechanical coupling part or the like, a protrusion may be formed on the surface of the main wing as the mechanical coupling part protrudes from the surface of the main wing, or a recess may be formed in the surface of the main wing as an attachment hole of the mechanical coupling part becomes deep. The protrusion and recess on the surface of the main wing influence the aerodynamic performance of an airplane. Hence, drilling, which allows a mechanical coupling part to pass through the main wing that is a workpiece, is performed with a precise machining position, a precise machining direction, and a precise machining amount so that the protrusion and the recess are minimized. Here, the machining direction is mainly an angle orthogonal to a workpiece, and it is necessary to obtain the normal vector on a surface to be machined. CITATION LIST Patent Literature [0005] [PTL 1] Japanese Unexamined Patent Application Publication No. 61-269002 [0006] [PTL 2] Japanese Unexamined Patent Application Publication No. 8-71823 SUMMARY OF INVENTION Technical Problem [0007] PTL 1 discloses a normal detection method that obtains the normal vector on the surface to be machined, and PTL 2 discloses a machining machine provided with a normal detection function. [0008] The normal detection method of PTL 1 is a method of obtaining the normal vector on a measured surface of a measurement subject by two opposed contact sensors among a plurality of contact sensors radially installed on a tip surface of an inner tube at one end coming into contact with the measurement subject and two opposed contact sensors installed on two protruding opposed tip surfaces of the outer tube at one end coming into contact with the measurement subject, in a movable normal detection jig in which the inner tube and the outer tube are coaxially fitted to each other and the outer tube is rotatable in a circumferential direction and movable in an axial direction with respect to the inner tube. [0009] This is a method of determining whether the axial direction of the normal detection jig is the same as the normal vector on the measured surface. That is, the axial direction of the normal detection jig should be sought such that the two opposed contact sensors of the inner tube detect the measurement subject and the two contact sensors installed at the tip of the outer tube detect the measurement subject. Hence, the operation for allowing the axial direction of the normal detection jig to coincide with the normal vector on the measured surface will take a substantial time. Additionally, in the normal detection method of PTL 1, it is difficult to automatically control the posture of the normal detection jig. [0010] The machining machine provided with a normal detection function of PTL 2 is a drilling machine provided with a machining jig in which two non-contact sensors are provided at one end and a motor-driven height adjustment mechanism is provided at the other end. The two non-contact sensors are arranged so as to become symmetrical with respect to the drilling tool, and the height adjustment mechanism is arranged so as to line up with the two non-contact sensors and the machining tool. By performing adjustment using the height adjustment mechanism so that measurement distances obtained by the two non-contact sensors become equal to each other, the angle of the machining machine to the surface to be machined is made right-angled. [0011] This is a device that detects perpendicularity with respect to one direction in which the two non-contact sensors and the height adjustment mechanism are lined up. Hence, since the perpendicularity to a direction different from the one direction cannot be detected, it is insufficient for obtaining the normal vector on the surface to be machined with high precision. [0012] The invention has been made in view of the above problems, and an object thereof is to calculate a normal vector on a measured surface with high precision from measurement distances obtained by distance detectors so that it is not necessary to search for the normal vector on the measured surface. Solution to Problem [0013] A normal detection method related to a first aspect of the invention to solve the above problems measures a plurality of distances to a measurement subject using one or a plurality of distance detectors, and obtains a normal vector on a measured surface of the measurement subject from the obtained measurement results. A plurality of measurement points on the measured surface at a plurality of measurement positions are represented by three-dimensional coordinates from the plurality of measurement positions where the distance detectors measure the distances to the measurement subject, and a plurality of measurement results obtained by the distance detectors at the plurality of measurement positions, a straight line connecting, on three-dimensional axes, a first measurement point measured at an arbitrary first measurement position among the plurality of measurement positions by the distance detector and a second measurement point measured at a second measurement position different from the first measurement position is defined as a first vector, a straight line connecting, on three-dimensional axes, the first measurement point and a third measurement point measured at a third measurement position different from the first measurement position and the second measurement position is defined as a second vector, and a normal vector on the measured surface is obtained by determining an outer product of the first vector and the second vector. [0014] In the normal detection method according to a second aspect of the invention to solve the above problems, the first measurement position, the second measurement position, and the third measurement position are selected so that the area of a triangle made with three points of the first measurement position, the second measurement position, and the third measurement position becomes the largest. [0015] In the normal detection method according to a third aspect of the invention to solve the above problems, the distance detectors are radially arranged in eight places including the first measurement position, the second measurement position, and the third measurement position. [0016] In the normal detection method according to a fourth aspect of the invention to solve the above problems, non-contact sensors are used as the distance detectors. [0017] A normal detection device related to a fifth aspect of the invention to solve the above problems includes one or a plurality of distance detectors that measure a distance to a measurement subject; and arithmetic means for representing a plurality of measurement points on the measured surface at a plurality of measurement positions by three-dimensional coordinates from the plurality of measurement positions where the distance detectors measure distances to the measurement subject, and a plurality of measurement results obtained by the distance detectors at the plurality of measurement positions, defining, as a first vector, a straight line connecting, on three-dimensional axes, a first measurement point measured at an arbitrary first measurement position among the plurality of measurement positions by the distance detector and a second measurement point measured at a second measurement position different from the first measurement position, defining, as a second vector, a straight line connecting, on three-dimensional axes, the first measurement point and a third measurement point measured at a third measurement position different from the first measurement position and the second measurement position, calculating a normal vector on the measured surface by an outer product of the first vector and the second vector, and calculating a machining vector passing through a setting point of a machining place using the calculated normal vector. [0018] A machining machine provided with a normal detection function according to a sixth aspect of the invention to solve the above problems includes the normal detection device according to the fifth aspect of the invention, and three-dimensional posture control means for three-dimensionally controlling the posture of the normal detection device and a machining tool to be the machining vector calculated by the arithmetic means. Advantageous Effects of Invention [0019] According to the normal detection method related to the first invention, since the normal vector is calculated from the first vector and the second vector that are not parallel to each other and are different from each other, the normal vector can be obtained with high precision. Additionally, since the normal vector on the measured surface can be calculated from the measurement distances obtained by the distance detectors, when the normal detection method related to the invention is applied to a machining machine or the like, it is easy to automatically control the posture of a machining tool or the like of the machining machine, and it is possible to shorten the working hours, which are taken for controlling the posture of the machining tool or the like of the machining machine so that the machining direction or the like of the machining machine coincides with the normal vector on the measured surface. [0020] According to the normal detection method related to the second invention, the first measurement position, the second measurement position, and the third measurement position are selected so that the area of the triangle made at the three points of the first measurement position, the second measurement position, and the third measurement position becomes the largest, and the first measurement position, the second measurement position, and the third measurement position are spaced apart from each other. Thus, the precision of the normal vector, which is calculated from the measurement distances at the first measurement position, the second measurement position, and the third measurement position obtained by the distance detectors, is improved. [0021] According to the normal detection method related to the third invention, simultaneous measurements are allowed in eight places by using the eight distance detectors that are radially installed. As a result, even when some distance detectors cannot perform effective measurement due to holes, end surfaces, or the like, the normal vector can be obtained from the measurement distances obtained by the other distance detectors that can perform effective measurement. [0022] According to the normal detection method related to the fourth invention, since the operation for bringing contact sensors into contact with a measurement subject is eliminated by using the non-contact sensors as the distance detectors, the working hours for obtaining the normal vector on the measured surface can be shortened. [0023] According to the normal detection device related to the fifth invention, since the normal vector is calculated from the first vector and the second vector that are not parallel and are different, the normal vector can be obtained with high precision. Additionally, since the normal vector on the measured surface can be calculated from the measurement distances obtained by the distance detectors, when the normal detection device related to the invention is applied to a machining machine or the like, it is easy to automatically control the posture of a machining tool or the like of the machining machine, and it is possible to shorten the working hours, which are taken for controlling the posture of the machining tool or the like of the machining machine so that the machining direction or the like of the machining machine coincides with the normal vector on the measured surface. [0024] According to the machining machine provided with a normal detection function related to the sixth invention, the normal vector on the measured surface is calculated by the normal detection device related to the fifth invention, and the posture of the machining tool is controlled in conformity with the calculated normal vector by the three-dimensional posture control means. Thus, the machining tool can be precisely and rapidly made to coincide with the normal vector, and machining in a precise normal direction can be processed. BRIEF DESCRIPTION OF DRAWINGS [0025] FIG. 1 is a conceptual diagram showing measurement using distance detectors related to Example 1. [0026] FIG. 2 is a plan view (as seen from a direction of arrow II in FIG. 3 ) showing the arrangement of the distance detectors in a machining jig related to Example 1. [0027] FIG. 3 is a side view as seen from a direction of arrow III of FIG. 2 . [0028] FIG. 4 is a plan view (as seen from a direction of arrow IV in FIG. 5 ) showing the machining jig related to Example 1 to which a parallel jig is attached. [0029] FIG. 5 is a side view as seen from a direction of arrow V of FIG. 4 . [0030] FIG. 6 is a plan view (as seen from a direction of arrow VI in FIG. 7 ) showing the machining jig related to Example 1 to which an inclined jig is attached. [0031] FIG. 7 is a side view as seen from a direction of arrow VII of FIG. 6 . [0032] FIG. 8A is a schematic view showing an example of the selection of forming a triangle with a largest area, in the arrangement of the distance detectors in the machining jig related to Example 1. [0033] FIG. 8B is a schematic view showing an example of the selection of forming a triangle with a second largest area, in the arrangement of the distance detectors in the machining jig related to Example 1. [0034] FIG. 8C is a schematic view showing an example of the selection of forming a triangle with a third largest area, in the arrangement of the distance detectors in the machining jig related to Example 1. [0035] FIG. 8D is a schematic view showing an example of the selection of forming a triangle with a fourth largest area, in the arrangement of the distance detectors in the machining jig related to Example 1. [0036] FIG. 8E is a schematic view showing an example of the selection of forming a triangle with a fifth largest area, in the arrangement of the distance detectors in the machining jig related to Example 1. DESCRIPTION OF EMBODIMENTS [0037] Hereinafter, examples of a normal detection method related to the invention will be described in detail with reference to the attached drawings. Of course, it is obvious that the invention is not limited to the following examples but various changes can be made without departing from the concept of the invention. Example 1 [0038] A normal detection method related to Example 1 of the invention will be described with reference to FIGS. 1 to 8 . [0039] In the present example, a machining jig 10 including a normal detection mechanism is attached to a machining machine (not shown) so as to allow machining from a normal direction on a measured surface 21 of a measurement subject 20 that is a workpiece. [0040] As shown in FIGS. 1 and 2 , the machining jig 10 includes non-contact sensors 30 that measure a distance to the measurement subject 20 , arithmetic means (not shown) for calculating a normal vector Vn and a machining vector Vm on the measured surface 21 from a measurement distance L obtained by the non-contact sensors 30 , and three-dimensional posture control means (not shown) for three-dimensionally controlling the posture of the machining jig 10 to be in a direction calculated by the arithmetic means, together with the machining machine (not shown). In the machining jig 10 of the present example, eight non-contact sensors 30 a , 30 b , 30 c , 30 d , 30 e , 30 f , 30 g , and 30 h are radially installed on a machining-side tip surface 11 of the machining jig 10 . [0041] Additionally, the machining jig 10 includes a machining-side tip hole 12 through which a parallel jig 40 ( FIGS. 4 and 5 ) performing Z-direction correction in the non-contact sensors 30 a to 30 h installed in the machining jig 10 and an inclined jig 50 ( FIGS. 6 and 7 ) that performing X-direction and Y-direction correction in the non-contact sensors 30 a to 30 h installed in the machining jig 10 are attachable and detachable. Here, the Z direction is a measurement direction of the non-contact sensors 30 a to 30 h , the X direction is an arbitrary direction orthogonal to the Z direction, and the Y-direction is a direction orthogonal to the Z direction and the X direction. In addition, the machining-side tip hole 12 is also used as a hole that allows a machining part of the machining machine (not shown) to pass therethrough during machining. [0042] The parallel jig 40 is a jig that performs the Z-direction correction in the non-contact sensors 30 a to 30 h , and as shown in FIGS. 4 and 5 , has an attachment cylindrical portion 41 to be fitted to the machining-side tip hole 12 of the machining jig 10 , and a Z-direction correction surface 42 that performs the Z-direction correction in the non-contact sensors 30 a to 30 h . If the attachment cylindrical portion 41 of the parallel jig 40 is inserted into the machining-side tip hole 12 of the machining jig 10 and the parallel jig 40 is fixed to the machining jig 10 , the Z-direction correction surface 42 perpendicularly intersects the Z direction that is a direction parallel to the machining-side tip surface 11 of the machining jig 10 , that is, the measurement direction of the non-contact sensors 30 a to 30 h , and is located at an arbitrary distance δz from the machining-side tip surface 11 of the machining jig 10 . In addition, since the Z-direction correction in the eight non-contact sensors 30 a to 30 h is performed, the Z-direction correction surface 42 is broad to such a degree that the eight non-contact sensors 30 a to 30 h can measure a distance to the Z-direction correction surface 42 . [0043] The inclined jig 50 is a jig that performs the X-direction and Y-direction correction in the non-contact sensors 30 a to 30 h , and as shown in FIGS. 6 and 7 , has an attachment cylindrical portion 51 to be fitted to the machining-side tip hole 12 of the machining jig 10 , and an XY-direction correction surface 52 that performs the Z-direction correction in the non-contact sensors 30 a to 30 h . If the attachment cylindrical portion 51 is inserted into the machining-side tip hole 12 and the inclined jig 50 is fixed to the machining jig 10 , the XY-direction correction surface 52 forms an arbitrary angle θ with respect to the machining-side tip surface 11 of the machining jig 10 , and a central portion 53 of the XY-direction correction surface 52 is located at an arbitrary distance δxy from the machining-side tip surface 11 of the machining jig 10 . In addition, since the XY-direction correction in the eight non-contact sensors 30 a to 30 h is performed, the XY-direction correction surface 52 is broad to such a degree that the eight non-contact sensors 30 a to 30 h can measure a distance to the XY-direction correction surface 52 . [0044] The XY-direction correction surface 52 can be attached so as to be parallel to the X direction by providing a protrusion (not shown) on an outer wall surface of the attachment cylindrical portion 51 of the inclined jig 50 , providing a first recess (not shown) in an inner wall surface of the machining-side tip hole 12 of the machining jig 10 and allowing the protrusion of the attachment cylindrical portion 51 of the inclined jig 50 and the first recess of the machining-side tip hole 12 of the machining jig 10 to engage with each other, and the XY-direction correction surface 52 can be attached so as to become parallel to the Y direction by providing a second recess (not shown) at a position rotated by 90° from the first recess in the circumferential direction in the inner wall surface of the machining-side tip hole 12 of the machining jig 10 and by allowing the protrusion of the attachment cylindrical portion 51 of the inclined jig 50 and the second recess of the machining-side tip hole 12 of the machining jig 10 to engage with each other. [0045] First, the Z-direction correction in the non-contact sensors 30 a to 30 h installed in the machining jig 10 , using the machining jig 10 and the parallel jig 40 , will be described with reference to FIG. 5 . [0046] The parallel jig 40 is attached to the machining jig 10 , and the distance to the Z-direction correction surface 42 of the parallel jig 40 is measured by the eight non-contact sensors 30 a to 30 h . The parallel jig 40 and the Z-direction correction surface 42 are formed so that the Z-direction correction surface 42 of the parallel jig 40 has the arbitrary distance 6 z from the machining-side tip surface 11 of the machining jig 10 , and are assembled to the machining jig 10 . Hence, the Z-direction correction in the eight non-contact sensors 30 a to 30 h can be performed by comparison with measurement distances Lza to Lzh to the Z-direction correction surface 42 obtained by the non-contact sensors 30 a to 30 h . That is, the installation positions of the eight non-contact sensors 30 a to 30 h in the Z direction with respect to the machining jig 10 can be precisely found out, relative errors caused by the assembling or the like of the eight non-contact sensors 30 a to 30 h to the machining jig 10 can be corrected for, and Z-direction distance measurement using the non-contact sensors 30 a to 30 h can be precisely performed. [0047] Next, the X-direction correction in the non-contact sensors 30 a to 30 h installed in the machining jig 10 , using the machining jig 10 and the inclined jig 50 , will be described with reference to FIG. 7 . [0048] The inclined jig 50 is attached to the machining jig 10 so that the XY-direction correction surface 52 becomes parallel to the Y direction, and the distance to the XY-direction correction surface 52 of the inclined jig 50 is measured by the eight non-contact sensors 30 a to 30 h . The inclined jig 50 and the XY-direction correction surface 52 are formed so that the XY-direction correction surface 52 has the arbitrary angle θ with respect to the machining-side tip surface 11 of the machining jig 10 and the central portion of the XY-direction correction surface has the arbitrary distance 6 xy from the machining-side tip surface 11 of the machining jig 10 , and are assembled to the machining jig 10 . Hence, the X-direction correction in the eight non-contact sensors 30 a to 30 h can be performed by calculation from measurement distances Lxa to Lxh obtained by the non-contact sensors 30 a to 30 h . That is, the installation positions Xa to Xh of the eight non-contact sensors 30 a to 30 h in the X direction with respect to the machining jig 10 can be precisely found out, relative errors caused by the assembling or the like of the eight non-contact sensors 30 a to 30 h to the machining jig 10 can be corrected for, and X-direction distance measurement using the non-contact sensors 30 a to 30 h can be precisely performed. [0049] Next, the Y-direction correction in the non-contact sensors 30 a to 30 h installed in the machining jig 10 , using the machining jig 10 and the inclined jig 50 , will be described with reference to FIG. 7 . [0050] The inclined jig 50 is attached to the machining jig 10 so that the XY-direction correction surface 52 becomes parallel to the X direction, and the distance to the XY-direction correction surface 52 of the inclined jig 50 is measured by the eight non-contact sensors 30 a to 30 h . The inclined jig 50 is formed so that the XY-direction correction surface 52 has the arbitrary angle θ and the central portion of the XY-direction correction surface has the arbitrary distance xy from the machining-side tip surface 11 of the machining jig 10 , and is assembled to the machining jig 10 . Hence, the Y-direction correction in the eight non-contact sensors 30 a to 30 h can be performed by calculation from measurement distances Lya to Lyh obtained by the non-contact sensors 30 a to 30 h . That is, the installation positions Ya to Yh of the eight non-contact sensors 30 a to 30 h in the Y direction with respect to the machining jig 10 can be precisely found out, relative errors caused by the assembling or the like of the eight non-contact sensors 30 a to 30 h to the machining jig 10 can be corrected for, and Y-direction distance measurement using the non-contact sensors 30 a to 30 h can be precisely performed. [0051] Next, the normal detection method of obtaining the normal vector Vn on the measured surface 21 , using the machining jig 10 , will be described with reference to FIG. 1 . [0052] The normal vector Vn is obtained by selecting three non-contact sensors from the eight non-contact sensors 30 a to 30 h installed in the machining jig 10 , and performing calculation from measurement distances La, Ld, and Lf obtained by non-contact sensors 30 a , 30 d , and 30 f of a selected combination to be described below, and installation positions (a first measurement position, a second measurement position, and a third measurement position) Pa (Xa, Ya), Pd (Xd, Yd), and Pf (Xf, Yf) of the non-contact sensors 30 a , 30 d , and 30 f of the selected combination. [0053] Measurement distances La to Lh to the measurement subject 20 is measured using the eight non-contact sensors 30 a to 30 h installed in the machining jig 10 . In the eight non-contact sensors 30 a to 30 h installed in the machining jig 10 , the number of combinations of selecting three non-contact sensors is fifty six ways, and is five ways if being classified according to the areas of triangles made by the respective combinations. [0054] For example, the number of combinations of obtaining triangles with a largest area is eight ways of selecting the non-contact sensors 30 a , 30 d , and 30 f , or the like, the number of combination of obtaining triangles with a second largest area is eight ways of selecting the non-contact sensors 30 a , 30 c , and 30 g , or the like, the number of combinations of obtaining triangles with a third largest area is sixteen ways of selecting the non-contact sensors 30 a , 30 b , and 30 f , or the like, the number of combinations of obtaining triangles with a fourth largest area is sixteen ways of selecting the non-contact sensors 30 a , 30 b , and 30 g , or the like, and the number of combinations of obtaining triangles with a smallest area is eight ways of selecting the non-contact sensors 30 a , 30 b , and 30 h , or the like. [0055] All the measurement distances La to Lh to the measurement subject 20 measured by the eight non-contact sensors 30 a to 30 h are not necessarily effective. That is, a hole is made at measurement points Qa to Qh of the measurement subject 20 or the measurement points Qa to Qh deviate from an end portion of the measurement subject 20 . However, the measurement distances La to Lh that are measurement results by all the non-contact sensors 30 a to 30 h are not necessarily obtained, and it is sufficient if a required number of effective measurement distances La to Lh are valid. When a required number of effective measurement distances La to Lh are not value, the required number of effective measurement distances La to Lh are valid by slightly translating the machining jig 10 and performing measurement using the non-contact sensors 30 a to 30 h. [0056] The non-contact sensors 30 a to 30 h to be used for the calculation of the normal detection are selected so that the area made by three non-contact sensors 30 selected from the non-contact sensors 30 a to 30 h by which the measurement distances La to Lh that are effective measurement results are obtained becomes the largest. [0057] Measurement points (a first measurement point, a second measurement point, and a third measurement point) Qa, Qd, and Qf on the measured surface 21 to be measured by the non-contact sensors 30 a , 30 d , and 30 f of the selected combination are represented by three-dimensional coordinates from the installation positions Pa (Xa, Ya), Pd (Xd, Yd), and Pf (Xf, Yf) of the non-contact sensors 30 a , 30 d , and 30 f in XY directions, and the measurement distances La, Ld, and Lf obtained by the non-contact sensors 30 a , 30 d , and 30 f. [0058] Measurement point Qa: (Xa, Ya, Za) [0059] Measurement point Qd: (Xd, Yd, Zd) [0060] Measurement point Of: (Xf, Yf, Zf) [0061] A vector (first vector) Vad connecting the measurement point Qa and the measurement point Qd measured by two arbitrary non-contact sensors 30 a and 30 d among the non-contact sensors 30 a , 30 d , and 30 f of the selected combination, and a vector (second vector) Vaf connecting the measurement point Qa and measurement point Qf measured by two arbitrary non-contact sensors 30 a and 30 f among the non-contact sensors 30 a , 30 d , and 30 f of the selected combination are calculated on the basis of the three-dimensional coordinates. [0000] Vad = s  ( Xd - Xa Yd - Ya Zd - Za ) + ( Xa Ya Za )   Vaf = t  ( Xf - Xa Yf - Ya Zf - Za ) + ( Xa Ya Za ) [ Formula   1 ] [0062] Here, s and t are arbitrary real numbers. [0063] The vector Vn that is an outer product of the vector Vad and the vector Vaf is calculated. The vector Vn is a direction vector orthogonal to the vector Vad and the vector Vaf, and represents a normal vector on the measured surface 21 . [0000] Vn =  Vaf × Vad =  u   ( ( Yf - Ya )  ( Zd - Za ) - ( Yd - Ya )  ( Zf - Za ) ( Zf - Za )  ( Xd - Xa ) - ( Zd - Za )  ( Xf - Xa ) ( Xf - Xa )  ( Yd - Ya ) - ( Xd - Xa )  ( Yf - Ya ) ) + ( Xa Ya Za ) [ Formula   2 ] [0064] Here, u is an arbitrary real number. [0065] The machining vector Vm passing through a set point Rm (Xm, Ym, Zm) of a machining place is calculated from the calculated normal vector Vn. [0000] Vm = v   ( ( Yf - Ya )  ( Zd - Za ) - ( Yd - Ya )  ( Zf - Za ) ( Zf - Za )  ( Xd - Xa ) - ( Zd - Za )  ( Xf - Xa ) ( Xf - Xa )  ( Yd - Ya ) - ( Xd - Xa )  ( Yf - Ya ) ) + ( Xm Ym Zm ) [ Formula   3 ] [0066] Here, v is an arbitrary real number. [0067] The posture of the machining jig 10 is controlled by three-dimensional posture control means so that the central axis of the machining jig 10 coincides with the obtained machining vector Vm. At this time, the measurement distances La, Ld, and Lf obtained by the opposed non-contact sensors 30 a , 30 d , and 30 f become the same value. [0068] By virtue of the above-described normal detection method and three-dimensional posture control, the normal vector Vn on the measured surface 21 can be obtained with high precision, the orientation of the machining jig 10 and the orientation of a machining tool of the machining machine (not shown) can be made to coincide with the calculated normal vector Vn, and machining in a precise normal direction can be performed. [0069] Additionally, the normal vector Vn on the measured surface 21 can also be obtained with higher precision not only by calculating the normal vector Vn from the measurement distances La, Ld, and Lf obtained by the non-contact sensors 30 a , 30 d , and 30 f of the selected combination and the installation positions Pa (Xa, Ya), Pd (Xd, Yd), and Pf (Xf, Yf) of the non-contact sensors 30 a , 30 d , and 30 f of the selected combination, but also, for example, by calculating a normal vector V′n from the measurement distances Lb, Le, and Lg obtained by the non-contact sensors 30 b , 30 e , and 30 g and the installation positions Pb (Xb, Yb), Pe (Xe, Ye), and Pg (Xg, Yg) of the non-contact sensors 30 b , 30 e , and 30 g of the selected combination, and taking the average of the plurality of normal vectors Vn and V′n. [0070] In addition, by repeating the operation of the normal detection method and three-dimensional posture control of the present example, the normal vector Vn on the measured surface 21 can be obtained with higher precision, and the machining jig 10 and the machining tool of the machining machine (not shown) can be made to coincide with the normal vector Vn that is calculated with higher precision. [0071] Since the normal detection is influenced by the measurement distances La to Lh obtained by the non-contact sensors 30 a to 30 h , precise measurement using the non-contact sensors 30 a to 30 h is required. Hence, in the present example, the X-direction, Y-direction, and Z-direction corrections of the eight non-contact sensors 30 a to 30 h attached to the machining jig 10 are performed. Of course, if precise measurement and installation using the non-contact sensors 30 are allowed in advance, the X-direction, Y-direction, and Z-direction corrections as in the present example are unnecessary. [0072] In the present example, the eight non-contact sensors 30 a to 30 h are radially installed as distance detectors to perform the normal detection, but the invention is not limited to this. For example, by making the non-contact sensors 30 movable, the normal vector Vn may be calculated from a plurality of measurement results measured at a plurality of measurement positions by one non-contact sensor 30 or the normal vector Vn may be calculated from measurement results using contact sensors as the distance detectors. [0073] Additionally, in the present example, the normal vector Vn is obtained using the machining jig 10 including the normal detection mechanism, but the invention is not limited to this. For example, the normal detection may be performed without using the machining jig 10 by providing the machining machine with the distance detectors, the arithmetic means, and the three-dimensional posture control means. INDUSTRIAL APPLICABILITY [0074] The normal detection method related to the invention can detect a normal vector on a target surface in a short time with high precision, and is very useful for the drilling that performs drilling in an aircraft main wing or the like. REFERENCE SIGNS LIST [0000] 10 : MACHINING JIG 11 : MACHINING-SIDE TIP SURFACE 12 : MACHINING-SIDE TIP HOLE 20 : MEASUREMENT SUBJECT 21 : MEASURED SURFACE 30 : NON-CONTACT SENSOR 40 : PARALLEL JIG 41 : ATTACHMENT CYLINDRICAL PORTION 42 : Z-DIRECTION CORRECTION SURFACE 50 : INCLINED JIG 51 : ATTACHMENT CYLINDRICAL PORTION 52 : XY-DIRECTION CORRECTION SURFACE 53 : CENTRAL PORTION

A normal detection method for measuring the distance to a measurement subject using one or more distance detectors, and obtaining a normal vector (Vn) on the measured surface of the measurement subject from the obtained measurement result (L), wherein: within a three-dimensional space, the straight line linking a first measurement point (Qa) measured at a first measurement position (Pa) using the distance detector and a second measurement point (Qd) measured at a second measurement position (Pd) different from the first measurement position (Pa) is set as a first vector (Vad); the straight line linking the first measurement point (Qa) and a third measurement point (Qf) measured at a third measurement position (Pf) different from the first measurement position (Pa) and the second measurement position (Pd) as a second vector (Vaf); and a normal vector (Vn) on the measured surface is obtained by determining the vector product of the first vector (Vad) and the second vector (Vaf).

TECHNICAL FIELD OF THE INVENTION [0001] This invention relates generally to a portable vacuum canister capable of interconnection with and deployment of waste into a sink drain having a waste grinder in direct communication with the sink drain flange covering a sink drain opening. The portable vacuum canister is used for vacuuming debris and dumping the debris into a garbage disposal or waste grinder associated with the sink for grinding of the debris, flushing and release into a municipal waste stream or septic system. BACKGROUND OF THE INVENTION [0002] Vacuum cleaning devices are designed by and large to operate by suctioning dust or debris from a surface. The general theory underlying the concept behind conventional vacuum cleaning devices is well-known. Typically, vacuum cleaning devices use some form of an electromechanical mechanism to create a partial vacuum to suction various kinds of particles into the vacuum cleaning device. Air pumps function by transferring air load from an inlet port to an outlet port (exhaust). The transfer of air load creates a region of lower pressure. The pressure gradient between this region of lower pressure and the ambient pressure creates suction, whereby particles are propelled toward the lower pressure region. The greater the pressure difference between the region of lower pressure and the region of ambient pressure, the greater the suction. [0003] From this fundamental principle of fluid dynamics, various prior vacuum cleaning devices have been developed to suction particles, with a large majority of these vacuum cleaning devices designed to suction debris from floors and carpets. Generally, the most popular current vacuum cleaning devices fall into one of several design categories: upright vacuum cleaners, hand-held vacuum cleaners, canister vacuum cleaners, backpack vacuum cleaners, and central vacuum systems, wherein a central location in a building provide vacuum inlets at strategic places throughout a building. [0004] In the specialized field encompassing vacuum devices designed specifically for suctioning debris from kitchen countertops, stoves, sinks and the like, and thereafter discharging the debris into a garbage disposal, the scope of the prior art is limited and includes especially few references. U.S. Pat. No. 6,434,783 to Arnold teaches of a vacuum system that employs a hose to suction waste materials from a sink. The waste materials are then transferred to a waste container. Similarly, U.S. Pat. No. 6,691,939 to Grimes teaches of a hose that sucks materials via a vacuum generator into a grinder/garbage disposal. Another reference, U.S. Pat. No. 4,641,392 to Huisma, teaches of a central vacuum system, wherein a vacuum tool is employed to suction debris from the kitchen sink area to the sewage system via conduits and a separator. [0005] The prior art described above suffers various deficiencies in its application of vacuuming debris from sinks and thereafter discharging the debris to a garbage disposal in a sink drain. Specifically, the prior art does not teach of a portable vacuum canister with an open bottom that is specially designed to adapt and slide into an existing sink drain flange in communication with a grinder or garbage disposal opening, such that debris, vacuumed by a hand-held hose, is directed into a disposal, ground up, and sent and washed down the drain. Accordingly, there is a need for a relatively simple, inexpensive and portable vacuum canister that can vacuum and dispose of debris into a garbage disposal in an efficient and non-labor intensive manner. SUMMARY OF INVENTION [0006] In accordance with the invention, there is provided a portable vacuum canister specially designed to correspondingly engage the opening of a sink drain flange covering a sink drain opening which is interconnected with a garbage disposal. The vacuum canister employs a suction hose for vacuuming debris; an airblower for generating vacuum; optionally a float cage with a float ball for permitting wet vacuum; a cyclone-shaped funnel for achieving constant suction, better dust separation and increased suction power; and an internal discharge control for selectively controlling discharge from the bottom of the vacuum canister during vacuum operation. [0007] The vacuum canister invention has many practical applications. The vacuum canister can be used for fast cleaning. In particular, the vacuum canister can be used to pick up and quickly dispose of biodegradable food, water and drinks that are on kitchen sinks, counter tops, toasters, cook tops, cook top hoods, ovens, cabinets, drawers, floors, high chairs, and any other conceivable object that would reside near a sink. [0008] The scope of the invention is indicated in the appended claims. It is intended that all changes or modifications within the meaning and range of equivalents are embraced by the claims. [0009] The foregoing and other features and advantages of the invention are apparent from the following detailed description of exemplary embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof. BRIEF DESCRIPTIONS OF THE DRAWINGS [0010] The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and configurations shown. [0011] FIG. 1A depicts an overall diagrammatic view of the inventive vacuum canister in operable connection with a sink drain flange and garbage disposal associated therewith. [0012] FIG. 1B provides an exploded view of the exterior housing for the inventive vacuum canister. [0013] FIG. 1C is a side elevational view illustrating a vacuum hose with attachments and accessories operable with the vacuum canister of the present invention. [0014] FIG. 1D is a perspective view illustrating airflow and debris movement within the inventive vacuum canister. [0015] FIG. 1E is a top elevational view, partial fragmentary view of an upper portion of the inventive vacuum canister. [0016] FIG. 2A is a perspective partially exploded view of an embodiment of the inventive vacuum canister having a backflow-flap-controlled discharge opening. [0017] FIG. 2B is a perspective view of an alternative embodiment of the inventive vacuum canister having a float-ball-valved discharge opening. [0018] FIG. 2C is a perspective view of another alternative embodiment of the inventive vacuum canister having a rotating cam valved discharge opening. [0019] FIG. 2D is a perspective view of yet another alternative embodiment of the inventive vacuum canister having a mechanical-dump-basket-controlled discharge opening. [0020] FIG. 3A is a perspective view illustrating yet another embodiment of the inventive vacuum canister having a backflow-flap-controlled discharge offset from center. [0021] FIG. 3B is a closer perspective view of the vacuum canister embodiment illustrated in FIG. 3A . [0022] FIG. 3C provides an overall diagrammatic view of the vacuum canister embodiment of FIG. 3A in operable connection with a drink drain flange and garbage disposal associated therewith. [0023] FIG. 4A is a perspective view illustrating yet another embodiment of the inventive vacuum canister having a paddle impeller for controlling discharge. [0024] FIG. 4B is a closer perspective view of the discharge control employed by the vacuum canister embodiment of FIG. 4A [0025] FIG. 4C is a perspective view of an impeller of the inventive vacuum canister embodiment of FIG. 4A . [0026] FIG. 4D is an exploded view of the impeller system of the vacuum canister embodiment of FIG. 4A incorporating a fan cage. [0027] FIG. 4E is an exploded view of the impeller system of the vacuum canister embodiment of FIG. 4A incorporating fan blades. [0028] FIG. 4F is a side view of the impeller system illustrated in FIG. 4E . [0029] FIG. 5 is a perspective view illustrating yet another embodiment of the inventive vacuum canister having an airblower mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0030] The invention is directed to a vacuum canister designed for vacuuming materials, such as particulates and/or fluids, from surfaces and transporting the materials to a sink drain having a grinder or garbage disposal mechanism coupled to the sink drain flange, releasing the materials through the sink drain flange and drain opening and into the grinder or garbage disposal mechanism for grinding an disposal into a municipal waste stream or septic system. FIG. 1A illustrates one preferred embodiment of the invention. The vacuum canister device 100 has two chambers, an upper first chamber 140 that is formed at an upper section of the vacuum canister 100 and a lower second chamber 150 that is formed at a lower section of the vacuum canister 100 . The upper first chamber 140 possesses a substantially cylindrical shape, while the lower second chamber 150 possesses a substantially frustroconical shape. A top region of the upper first chamber 140 is occupied by a vacuum generating element 130 . This vacuum generating element 130 can be an airblower or any other electromechanical mechanism that generates vacuum inside the canister device 100 . A standard airblower can include a motor powered fan or impeller enclosed in a blower housing. Inside the upper chamber 140 , it is desirable to provide a removable filter housing 160 with a float ball 165 is provided to allow for wet vacuuming. [0031] FIG. 11B provides an exploded view of the canister's casing. Suction hose 120 is interconnected with the upper first chamber 140 . Preferably, the suction hose 120 is formed of a lightweight and flexible material, such as polyvinyl chloride, rubber or any material widely known in the vacuum hose art, to allow for easy handling. Naturally, a person skilled in the art could also select another material not described above (such as soft flexible metal) which has been associated with vacuum hoses. Although not shown, the vacuum hose 120 can also be corrugated, so that it is shaped to have folds, ridges or grooves. As shown on FIG. 1C , the suction hose 120 is provided a vacuum head 121 , designed to possess a large surface area for vacuuming even large pieces of debris. Additionally, various attachments can be appended to the suction hose 120 and/or vacuum head 121 to provide for additional cleaning options. For example, the vacuum head 121 can be fastened with a scouring pad/sponge 122 , formed of tough fibers and abrasives, for scouring pots and pans. Likewise, a cleaning fluid dispenser 123 can also be employed for dispensing cleaning fluid to the vacuum head 121 via a fluid carrying hose 124 . Additionally, an on/off switch can be designed to be on the end of the suction hose 120 near the vacuum head 121 , instead of on the vacuum canister 100 itself, so that a user can effortlessly turn on/off vacuuming. Although not shown in the drawings, the suction hose 120 can also be designed to be retractable to the vacuum canister 100 , thereby providing easier use to the user. [0032] Referring back to FIG. 1A , the lower second chamber 150 possesses a substantially conical shape. Near the bottom of the lower second chamber 150 , a discharge control 170 is provided to close shut what would otherwise be a bottomless canister. When the discharge control 170 is in an open state, particles, suctioned through suction hose 120 and transferred down the vacuum canister 100 , pass through a flange 190 a and are discharged into a drain 182 of a kitchen sink 181 . Therefrom, the particles descend to a garbage disposal 183 , installed under the kitchen sink 181 , where the particles are ground up and shredded into small pieces, so they can be passed through plumbing without clogging. [0033] FIG. 1D provides a closer view of the above-described embodiment of the invention. Additionally, FIG. 1D illustrates the air pathway taken by particles and fluids suctioned from a vacuum head 121 on suction hose 120 . Initially, the particles enter through a vacuum head 121 of the suction hose 120 . Thereafter, the particles pass through the length of the suction hose and enter the first upper chamber 140 of the vacuum canister device 100 . FIG. 1E provides a top view of the upper first chamber 140 . Immediately upon entering the upper first chamber 140 , the incoming particles crash hard against a wall of upper first chamber 140 and into the air already being evacuated through the spinning downward spiral action inside the cyclone. The resulting crash in turbulence breaks the heavier and lighter particles apart, and the spinning air throws the heavy particles outward against the cyclone walls. Air flow at the cyclone walls is slowed by friction. As a result, heavier particles get trapped in the slower moving air. Slowly, gravitational forces pull these heavier particles down. The cone-shaped bottom of the cyclone-shaped vacuum canister is designed to be angled at a proper degree to keep the air speed constant. This design keeps the heavier particles pressed tightly to the cyclone walls of the lower second chamber 150 . As a result, the heavier particles slide downward and along the cyclone walls of the lower second chamber 150 . Eventually, these heavier particles fall and become trapped at the bottom of the vacuum canister 100 . Near the bottom of the cone is an area called a reversal point where the spinning air without the heavier particles reverses direction. This clean air then spirals up through the center of the cyclone and then exits through the cyclone outlet through the exhaust. [0034] At the bottom of the lower second chamber 150 , a discharge control 170 is employed for controlling the opening and closing of the vacuum canister 100 . A flange 190 a is provided for discharging particles and fluids from the vacuum canister 100 . The flange 190 a is designed to fittingly and sealingly engage the drain 182 of a sink 181 and is thereby interconnected to a garbage disposal 183 . [0035] In one embodiment, the bottom of the vacuum canister 100 is closed during vacuum operation and opened when vacuum operation is off. In this particular embodiment, closing shut the bottom of the vacuum canister 100 during operation helps the vacuum canister 100 sustain the pressure gradient needed to generate suction. After operation, when the pressure gradient is no longer necessary, the discharge control 170 opens the bottom of the vacuum canister 100 to permit dumping of debris into the drain 182 and subsequently into the garbage disposal 183 . [0036] Various possible discharge controls 170 are available. In the embodiment of FIG. 2A , a backflow valve 171 a is used to control flow of debris coming out of the vacuum canister 100 . Essentially, the backflow valve 171 a prevents fluids from flowing in a direction opposite that of intended flow. Thus, the backflow valve 171 a allows fluids to flow in only one direction, namely in the direction of discharge. To achieve this control, the backflow valve 171 a uses a backflow flap 172 a , capable of two possible positions, an opened position and a closed position. The backflow flap 172 a is fastened to a hinged spring. In the embodiment of FIG. 2A , the opening and closing of the backflow flap 172 a is controlled by suction. During vacuum operation, suction causes the backflow flap 172 a to be lifted into a closed position. This action temporarily causes a vacuum trap. The closing of the discharge control 170 of the vacuum canister 100 allows for particles to be collected on a collection bin 173 a with a flap dam 174 located at the lower portion of the collection bin 173 a . When vacuum operation shuts down, natural gravitational forces and the lack of suction causes the backflow flap 172 a to slide down and descend into an opened position. Accordingly, particles accumulated in the collection bin 173 a falls downwards through the backflow valve 171 a and into the drain 182 . [0037] Referring to FIGS. 2B-2D , alternative discharge controls 170 are shown, wherein the same or similar reference numbers refer to the same or similar structure. [0038] In the alternative discharge control 170 embodiment of FIG. 2B , a float ball 176 is enclosed inside a float ball cage 177 . The float ball cage 177 extends upwards and borders a float ball dam 175 . During vacuum operation, the float ball 176 is suctioned upwards thereby closing shut the discharge control 170 and thus the bottom of the vacuum canister 100 . When vacuum operation shuts down, natural gravitational forces and the lack of suction causes the float ball 176 to descend into a lower position, thereby allowing particles accumulated on the collection bin 173 a to fall downwards through the float ball dam 175 into the drain 182 . [0039] FIG. 2C illustrates another possible discharge control 170 . In this embodiment, a rotating cam 178 or slide gate valve is used to open or close the bottom of the vacuum canister. A user could open and close the bottom of the vacuum canister 100 by manually turning the rotating cam. Similarly, in the discharge control 170 illustrated in FIG. 2D , a mechanical dump basket 179 is used to close shut the bottom of the vacuum canister 100 . After vacuum operation is over, a user could take out the mechanical dump basket 179 to manually dump the collected debris into a drain 182 . [0040] In the preferred embodiment illustrated in FIG. 3A , the vacuum canister 100 is designed to have an overall cylindrical shape. In contrast to the above-mentioned embodiments previously described, wherein the upper portion of the vacuum canister is formed in a cylindrical shape while the lower portion of the vacuum canister is formed in a conical-cyclonic shape, the entire vacuum canister 100 embodied in FIG. 3A , from top to bottom, is formed exteriorly in a substantially cylindrical shape. This cylindrical-shape feature enhances stability of the vacuum canister 100 by lowering the vacuum canister's center of gravity. Accordingly, the vacuum canister 100 is less likely to rock back and forth during operation. In this preferred embodiment, vacuum generating element 130 is situated at the top of the vacuum canister 100 . The vacuum generating element 130 creates vacuum through a motor 131 connected to an impeller/airblower 132 by a rod 133 . An exhaust outlet 134 is provided for releasing air. The exhaust outlet 134 interconnects a filter receiver 135 , which is sized to slidably receive a filter 136 . Similar to the above-mentioned embodiments, a cone-shaped funnel 137 is employed to generate the cyclone action that is effective for achieving constant suction, better dust separation, and increased suction power. Dead spaces 138 are incorporated into the vacuum canister 100 to provide the vacuum canister 100 with an exterior cylindrical shape. These dead spaces 138 are positioned between the cone-shaped funnel 137 and the shell outward wall 139 . The dead spaces can be left empty with air, or they can be filled with sound reducing materials to drown out noise generated during operation of the vacuum canister 100 . [0041] Just like the embodiments described above, the bottom of the vacuum canister 100 embodiment of FIG. 3A includes a discharge control 170 . Similar to the embodiment of FIG. 2A , a backflow valve 171 b with backflow flap 172 b is adopted for controlling the discharging of particles and fluids. The backflow flap 172 b is capable of two possible positions, an opened position and a closed position. The backflow flap 172 b is fastened to a hinged spring. In this preferred embodiment, the opening and closing of the backflow flap 172 b is controlled by vacuum suction. During vacuum operation, vacuum suction causes the backflow flap 172 b to be lifted into a closed position. This action temporarily causes a vacuum trap. The closing of the discharge control 170 allows for particles to be collected on a chute 173 b , which is positioned below the cone-shaped funnel 137 . When vacuum operation shuts down, natural gravitational forces and the lack of suction will cause the backflow flap 172 b to slide down and descend into an opened position. Accordingly, particles and fluids accumulated in the discharge chute 173 b fall down through the backflow valve 171 b and into the drain 182 . A flange 190 b is provided for discharging particles and fluids from the vacuum canister 100 . The flange 190 b is designed to fittingly and sealingly engage the drain 182 of a sink 181 and is thereby interconnected to a garbage disposal 183 . In the embodiment shown in FIG. 3A , the flange 190 b is designed to be offset from the center of the vacuum canister bottom 191 . This design makes it easier for a user to place and fit the vacuum canister over the drain 182 . A closer inside view of the vacuum canister embodiment of FIG. 3A is provided in FIG. 3B . FIG. 3C provides an exterior view of the vacuum canister embodiment illustrated in FIG. 3A . [0042] FIG. 4A illustrates another embodiment of the invention. The vacuum canister device 200 retains a substantially cylindrical shape, except for the portion near the bottom of the vacuum canister. The top portion of the vacuum canister is occupied by a vacuum generating element 230 . As described above, the vacuum generating element 230 can be an airblower or any other contraption that generates vacuum inside the canister 200 . The standard airblower can include a motor powered fan or impeller 232 enclosed in a blower housing. The suction hose 220 is interconnected with the upper portion of the vacuum canister 200 . The pathway shown in FIG. 1E and previously described is also applicable to the embodiment of FIG. 4A . As the particles and fluids enter the cyclone section 237 of the vacuum canister 200 , the particles and fluids are separated in a manner similar to that described above for other embodiments. The exhaust air travel upwards and pass through a screen 234 and into a chamber 236 . From there, the exhaust air enters a channel tube 201 . In contrast, the heavier particles fall downwards in a spiraling manner and exits the cyclone section 237 into a collection chamber 250 . [0043] The embodiment of FIG. 4A differs from the previously described embodiments in the discharge control 270 employed for discharging particles and fluids. The embodiment of FIG. 4A uses a paddle impeller 271 situated at the bottom portion of the vacuum canister 200 . The paddle impeller 271 is formed with a plurality of paddles 272 that revolves in a spinning manner. As illustrated in FIG. 4F , with each rotation, the paddles collect particles 281 and fluids from a collection chamber 250 when in an upward-facing state and empty particles 281 and fluids when in a downward-facing state. The discharged particles and fluids pass through a discharge chamber 280 before exiting the vacuum canister through a flange 290 . The paddle impeller 271 can be designed to rotate in a clockwise direction or in a counterclockwise direction. As illustrated in FIG. 4A , the exhausted air generated by the vacuum generating element 230 is captured and sent down a channel tube 201 . This exhaust air blows on the fan cage 273 of the paddle impeller 271 thus powers the paddle impeller 271 . Thereafter, exhausted air continues through inner carry tube 202 and passes through a connecting tube 203 before exiting into the direction of the rotating paddles 272 . As it exits the connecting tube 203 , the exhaust air blows trapped particles off the rotating paddles 272 , thereby cleaning the rotating paddles 272 . [0044] FIG. 4B gives a closer view of the discharge control 270 employed by the vacuum canister 200 embodiment of FIG. 4A . A person of ordinary skill in the art would recognize that various types of fan contraptions could be used to capture the energy from the exhaust air and transfer this energy into rotational movement of the paddle impeller 271 . For instance, fan blades 274 can be used in lieu of a fan cage 273 for capturing the energy necessary to power the paddle impeller 271 . FIG. 4C presents a perspective view of the paddle impeller 271 comprising of fan blades 274 joined to the inner carry tube 202 that is connected to a plurality of paddles 272 . FIG. 4D provides an exploded view of the paddle impeller 271 . The paddle impeller 271 is comprised of the fan cage 273 , the carry tube 202 , and paddles 272 . Alternatively, as shown in FIG. 4E , when fan blades are 274 are used, the paddle impeller 271 would comprise of fan blades 274 , the carry tube 202 , and paddles 272 . [0045] FIG. 5 illustrates another inventive embodiment of the vacuum canister 300 . As shown in FIG. 5 , the vacuum canister device 300 possesses a substantially cylindrical shape. A vacuum generating element 330 is used to create vacuum. This vacuum generating element 330 can be an airblower or any other contraption that suctions particles into the vacuum canister 300 via a suction hose 320 and a suction inlet 321 interconnected to the vacuum canister 300 and simultaneously blows these particles out of the vacuum canister 300 through a flange 390 . The standard airblower can include a motor 331 powering an impeller 332 or fan rotating via a rod 333 . The airblower is enclosed in a blower housing. The exhaust air vent out to the side through a filter 336 . Additionally, insulation 308 can be provided to lessen the noise stemming from the motor during operation. [0046] Essentially, the invention embodied in FIG. 5 operates by having a motor 331 spin an impeller 332 or fan, thereby creating suction and pulling all air, particles, and fluids into the vacuum canister 300 through the impeller 332 or fan. Simultaneously, the motor creates a blowing action, whereby air, particles, and particles are blown out of the vacuum canister 300 into the sink drain 382 and eventually into the garbage disposal 383 . Unlike previous inventive embodiments, the vacuumed particles and fluids are not held or stored inside the vacuum canister 300 . Thus, a discharge control, like those in the previous embodiments, may not be necessary. [0047] The above-described vacuum canisters and methods are example implementations. The implementations illustrate possible approaches for removing debris from a sink area and discharging the debris into a vacuum canister designed to fittingly and sealingly engage a sink drain. The actual implementation may vary from the configurations discussed. Moreover, various other improvements and modifications to this invention may occur to those skilled in the art, and those improvements and modifications will fall within the scope of this invention as set forth in the claims below. [0048] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. Therefore, the scope of the invention is not limited to the specific exemplary embodiment described above. All changes or modifications within the meaning and range of equivalents are intended to be embraced herein. [0049] As used in this application, the articles “a” and “an” refer to one or more than one (i.e., to at least one) of the grammatical objects of the article. By way of example, “an element” means one element or more than one element.

A portable vacuum canister is disclosed for vacuuming debris by a hand-held suction hose and for transferring the debris down through the vacuum canister and into an existing garbage disposal for grinding, where it is then washed down the drain. The vacuum canister adapts and slides into an existing disposal opening.

This application is a continuation of U.S. Ser. No. 08/544,837, filed Oct. 18, 1995, now U.S. Pat. No. 5,845,215. BACKGROUND Applicants' invention relates to electrical telecommunication, and more particularly to wireless communication systems, such as cellular and satellite radio systems, for various modes of operation (analog, digital, dual mode, etc.), and access techniques such as frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), and hybrid FDMA/TDMA/CDMA. The specific aspects of the invention are directed to techniques for enhancing procedures for reception and transmission of information. A description follows which is directed to environments in which this invention may be applied. This general description is intended to provide a general overview of known systems and associated terminology so that a better understanding of the invention can be obtained. In North America, digital communication and multiple access techniques such as TDMA are currently provided by a digital cellular radiotelephone system called the digital advanced mobile phone service (D-AMPS), some of the characteristics of which are specified in the interim standard TIA/EIA/IS-54-B, "Dual-Mode Mobile Station-Base Station Compatibility Standard", published by the Telecommunications Industry Association and Electronic Industries Association (TIA/EIA), the disclosure of which is expressly incorporated here by reference. Because of a large existing consumer base of equipment operating only in the analog domain with frequency-division multiple access (FDMA), TIA/EIA/IS-54-B is a dual-mode (analog and digital) standard, providing for analog compatibility together with digital communication capability. For example, the TIA/EIA/IS-54-B standard provides for both FDMA analog voice channels (AVC) and TDMA digital traffic channels (DTC). The AVCs and DTCs are implemented by frequency modulating radio carrier signals, which have frequencies near 800 megahertz (MHz) such that each radio channel has a spectral width of 30 kilohertz (KHz). In a TDMA cellular radiotelephone system, each radio channel is divided into a series of time slots, each of which contains a burst of information from a data source, e.g., a digitally encoded portion of a voice conversation. The time slots are grouped into successive TDMA frames having a predetermined duration. The number of time slots in each TDMA frame is related to the number of different users that can simultaneously share the radio channel. If each slot in a TDMA frame is assigned to a different user, the duration of a TDMA frame is the minimum amount of time between successive time slots assigned to the same user. The successive time slots assigned to the same user, which are usually not consecutive time slots on the radio carrier, constitute the user's digital traffic channel, which may be considered a logical channel assigned to the user. As described in more detail below, digital control channels (DCCs) can also be provided for communicating control signals, and such a DCC is a logical channel formed by a succession of usually non-consecutive time slots on the radio carrier. In only one of many possible embodiments of a TDMA system as described above, the TIA/EIA/IS-54-B standard provided that each TDMA frame consists of six consecutive time slots and has a duration of 40 milliseconds (msec). Thus, each radio channel can carry from three to six DTCs (e.g., three to six telephone conversations), depending on the source rates of the speech coder/decoders (codecs) used to digitally encode the conversations. Such speech codecs can operate at either full-rate or half-rate. A full-rate DTC requires twice as many time slots in a given time period as a half-rate DTC, and in TIA/EIA/IS-54-B, each full-rate DTC uses two slots of each TDMA frame, i.e., the first and fourth, second and fifth, or third and sixth of a TDMA frame's six slots. Each half-rate DTC uses one time slot of each TDMA frame. During each DTC time slot, 324 bits are transmitted, of which the major portion, 260 bits, is due to the speech output of the codec, including bits due to error correction coding of the speech output, and the remaining bits are used for guard times and overhead signalling for purposes such as synchronization. It can be seen that the TDMA cellular system operates in a buffer-and-burst, or discontinuous-transmission, mode: each mobile station transmits (and receives) only during its assigned time slots. At full rate, for example, a mobile station might transmit during slot 1, receive during slot 2, idle during slot 3, transmit during slot 4, receive during slot 5, and idle during slot 6, and then repeat the cycle during succeeding TDMA frames. Therefore, the mobile station, which may be battery-powered, can be switched off, or sleep, to save power during the time slots when it is neither transmitting nor receiving. In addition to voice or traffic channels, cellular radio communication systems also provide paging/access, or control, channels for carrying call-setup messages between base stations and mobile stations. According to TIA/EIA/IS-54-B, for example, there are twenty-one dedicated analog control channels (ACCs), which have predetermined fixed frequencies for transmission and reception located near 800 MHz. Since these ACCs are always found at the same frequencies, they can be readily located and monitored by the mobile stations. For example, when in an idle state (i.e., switched on but not making or receiving a call), a mobile station in a TIA/EIA/IS-54-B system tunes to and then regularly monitors the strongest control channel (generally, the control channel of the cell in which the mobile station is located at that moment) and may receive or initiate a call through the corresponding base station. When moving between cells while in the idle state, the mobile station will eventually "lose" radio connection on the control channel of the "old" cell and tune to the control channel of the "new" cell. The initial tuning and subsequent re-tuning to control channels are both accomplished automatically by scanning all the available control channels at their known frequencies to find the "best" control channel. When a control channel with good reception quality is found, the mobile station remains tuned to this channel until the quality deteriorates again. In this way, mobile stations stay "in touch" with the system. While in the idle state, a mobile station must monitor the control channel for paging messages addressed to it. For example, when an ordinary telephone (land-line) subscriber calls a mobile subscriber, the call is directed from the public switched telephone network (PSTN) to a mobile switching center (MSC) that analyzes the dialed number. If the dialed number is validated, the MSC requests some or all of a number of radio base stations to page the called mobile station by transmitting over their respective control channels paging messages that contain the mobile identification number (MIN) of the called mobile station. Each idle mobile station receiving a paging message compares the received MIN with its own stored MIN. The mobile station with the matching stored MIN transmits a page response over the particular control channel to the base station, which forwards the page response to the MSC. Upon receiving the page response, the MSC selects an AVC or a DTC available to the base station that received the page response, switches on a corresponding radio transceiver in that base station, and causes that base station to send a message via the control channel to the called mobile station that instructs the called mobile station to tune to the selected voice or traffic channel. A through-connection for the call is established once the mobile station has tuned to the selected AVC or DTC. The performance of the system having ACCs that is specified by TIA/EIA/IS-54-B has been improved in a system having digital control channels (DCCHs) that is specified in TIA/EIA/IS-136, the disclosure of which is expressly incorporated here by reference. Using such DCCHs, each TIA/EIA/IS-54-B radio channel can carry DTCs only, DCCHs only, or a mixture of both DTCs and DCCHs. Within the TIA/EIA/IS-54-B framework, each radio carrier frequency can have up to three full-rate DTCs/DCCHs, or six half-rate DTCs/DCCHs, or any combination in between, for example, one full-rate and four half-rate DTCs/DCCs. In general, however, the transmission rate of the DCCH need not coincide with the half-rate and full-rate specified in TIA/EIA/IS-54-B, and the length of the DCC slots may not be uniform and may not coincide with the length of the DTC slots. The DCCH may be defined on a TIA/EIA/IS-54-B radio channel and may consist, for example, of every n-th slot in the stream of consecutive TDMA slots. In this case, the length of each DCCH slot may or may not be equal to 6.67 msec, which is the length of a DTC slot according to TIA/EIA/IS-54-B. Alternatively (and without limitation on other possible alternatives), these DCCH slots may be defined in other ways known to one skilled in the art. In cellular telephone systems, an air link protocol is required in order to allow a mobile station to communicate with the base stations and MSC. The communications link protocol is used to initiate and to receive cellular telephone calls. The communications link protocol is commonly referred to within the communications industry as a Layer 2 protocol, and its functionality includes the delimiting, or framing, of Layer 3 messages. These Layer 3 messages may be sent between communicating Layer 3 peer entities residing within mobile stations and cellular switching systems. The physical layer (Layer 1) defines the parameters of the physical communications channel, e.g., radio frequency spacing, modulation characteristics, etc. Layer 2 defines the techniques necessary for the accurate transmission of information within the constraints of the physical channel, e.g., error correction and detection, etc. Layer 3 defines the procedures for reception and processing of information transmitted over the physical channel. Communications between mobile stations and the cellular switching system (the base stations and the MSC) can be described in general with reference to FIGS. 1, 2(a), and 2(b). FIG. 1 schematically illustrates pluralities of Layer 3 messages 11, Layer 2 frames 13, and Layer 1 channel bursts, or time slots, 15. In FIG. 1, each group of channel bursts corresponding to each Layer 3 message may constitute a logical channel, and as described above, the channel bursts for a given Layer 3 message would usually not be consecutive slots on an TIA/EIA/136 carrier. On the other hand, the channel bursts could be consecutive; as soon as one time slot ends, the next time slot could begin. Each Layer 1 channel burst 15 contains a complete Layer 2 frame as well as other information such as, for example, error correction information and other overhead information used for Layer 1 operation. Each Layer 2 frame contains at least a portion of a Layer 3 message as well as overhead information used for Layer 2 operation. Although not indicated in FIG. 1, each Layer 3 message would include various information elements that can be considered the payload of the message, a header portion for identifying the respective message's type, and possibly padding. Each Layer 1 burst and each Layer 2 frame is divided into a plurality of different fields. In particular, a limited-length DATA field in each Layer 2 frame contains the Layer 3 message 11. Since Layer 3 messages have variable lengths depending upon the amount of information contained in the Layer 3 message, a plurality of Layer 2 frames may be needed for transmission of a single Layer 3 message. As a result, a plurality of Layer 1 channel bursts may also be needed to transmit the entire Layer 3 message as there is a one-to-one correspondence between channel bursts and Layer 2 frames. As noted above, when more than one channel burst is required to send a Layer 3 message, the several bursts are not usually consecutive bursts on the radio channel. Moreover, the several bursts are not even usually successive bursts devoted to the particular logical channel used for carrying the Layer 3 message. Since time is required to receive, process, and react to each received burst, the bursts required for transmission of a Layer 3 message are usually sent in a staggered format, as schematically illustrated in FIG. 2(a) and as described above in connection with the TIA/EIA/IS-136 standard. FIG. 2(a) shows a general example of a forward (or downlink) DCCH configured as a succession of time slots 1, 2, . . . , N . . . included in the consecutive time slots 1, 2, . . . sent on a carrier frequency. These DCCH slots may be defined on a radio channel such as that specified by TIA/EIA/IS-136, and may consist, as seen in FIG. 2(a) for example, of every n-th slot in a series of consecutive slots. Each DCCH slot has a duration that may or may not be 6.67 msec, which is the length of a DTC slot according to the TIA/EIA/IS-136 standard. As shown in FIG. 2(a), the DCCH slots may be organized into superframes (SF), and each superframe includes a number of logical channels that carry different kinds of information. One or more DCCH slots may be allocated to each logical channel in the superframe. The exemplary downlink superframe in FIG. 2(a) includes three logical channels: a broadcast control channel (BCCH) including six successive slots for overhead messages; a paging channel (PCH) including one slot for paging messages; and an access response channel (ARCH) including one slot for channel assignment and other messages. The remaining time slots in the exemplary superframe of FIG. 2(a) may be dedicated to other logical channels, such as additional paging channels PCH or other channels. Since the number of mobile stations is usually much greater than the number of slots in the superframe, each paging slot is used for paging several mobile stations that share some unique characteristic, e.g., the last digit of the MIN. FIG. 2(b) illustrates a preferred information format for the slots of a forward DCCH. The invention transmitted in each slot comprises a plurality of fields, and FIG. 2(b) indicates the number of bits in each field above that field. The bits sent in the SYNC field are used in a conventional way to help ensure accurate reception of the coded superframe phase (CSFP) and DATA fields. The SYNC field includes a predetermined bit pattern used by the base stations to find the start of the slot. The shared channel feedback (SCF) field is used to control a random access channel (RACH), which is used by the mobile to request access to the system. The CSFP field conveys a coded superframe phase value that enables the mobile stations to find the start of each superframe. This is just one example for the information format in the slots of the forward DCCH. For purposes of efficient sleep mode operation and fast cell selection, the BCCH may be divided into a number of sub-channels. A BCCH structure is known that allows the mobile station to read a minimum amount of information when it is switched on (when it locks onto a DCCH) before being able to access the system (place or receive a call). After being switched on, an idle mobile station needs to regularly monitor only its assigned PCH slots (usually one in each superframe); the mobile can sleep during other slots. The ratio of the mobile's time spent reading paging messages and its time spent asleep is controllable and represents a tradeoff between call-set-up delay and power consumption. Since each TDMA time slot has a certain fixed information carrying capacity, each burst typically carries only a portion of a Layer 3 message as noted above. In the uplink direction, multiple mobile stations attempt to communicate with the system on a contention basis, while multiple mobile stations listen for Layer 3 messages sent from the system in the downlink direction. In known systems, any given Layer 3 message must be carried using as many TDMA channel bursts as required to send the entire Layer 3 message. Digital control and traffic channels are desirable for reasons, such as supporting longer sleep periods for the mobile units, which results in longer battery life. Digital traffic channels and digital control channels have expanded functionality for optimizing system capacity and supporting hierarchical cell structures, i.e., structures of macrocells, microcells, picocells, etc. The term "macrocell" generally refers to a cell having a size comparable to the sizes of cells in a conventional cellular telephone system (e.g., a radius of at least about 1 kilometer), and the terms "microcell" and "picocell" generally refer to progressively smaller cells. For example, a microcell might cover a public indoor or outdoor area, e.g., a convention center or a busy street, and a picocell might cover an office corridor or a floor of a high-rise building. From a radio coverage perspective, macrocells, microcells, and picocells may be distinct from one another or may overlap one another to handle different traffic patterns or radio environments. FIG. 3 is an exemplary hierarchical, or multi-layered, cellular system. An umbrella macrocell 10 represented by a hexagonal shape makes up an overlying cellular structure. Each umbrella cell may contain an underlying microcell structure. The umbrella cell 10 includes microcell 20 represented by the area enclosed within the dotted line and microcell 30 represented by the area enclosed within the dashed line corresponding to areas along city streets, and picocells 40, 50, and 60, which cover individual floors of a building. The intersection of the two city streets covered by the microcells 20 and 30 may be an area of dense traffic concentration, and thus might represent a hot spot. FIG. 4 represents a block diagram of an exemplary cellular mobile radiotelephone system, including an exemplary base station 110 and mobile station 120. The base station includes a control and processing unit 130 which is connected to the MSC 140 which in turn is connected to the PSTN (not shown). General aspects of such cellular radiotelephone systems are known in the art, as described by U.S. Pat. No. 5,175,867 to Wejke et al., entitled "Neighbor-Assisted Handoff in a Cellular Communication System," which is incorporated in this application by reference. The base station 110 handles a plurality of voice channels through a voice channel transceiver 150, which is controlled by the control and processing unit 130. Also, each base station includes a control channel transceiver 160, which may be capable of handling more than one control channel. The control channel transceiver 160 is controlled by the control and processing unit 130. The control channel transceiver 160 broadcasts control information over the control channel of the base station or cell to mobiles locked to that control channel. It will be understood that the transceivers 150 and 160 can be implemented as a single device, like the voice and control transceiver 170, for use with DCCHs and DTCs that share the same radio carrier frequency. The mobile station 120 receives the information broadcast on a control channel at its voice and control channel transceiver 170. Then, the processing unit 180 evaluates the received control channel information, which includes the characteristics of cells that are candidates for the mobile station to lock on to, and determines on which cell the mobile should lock. Advantageously, the received control channel information not only includes absolute information concerning the cell with which it is associated, but also contains relative information concerning other cells proximate to the cell with which the control channel is associated, as described in U.S. Pat. No. 5,353,332 to Raith et al., entitled "Method and Apparatus for Communication Control in a Radiotelephone System," which is incorporated in this application by reference. To increase the user's "talk time", i.e., the battery life of the mobile station, a digital forward control channel (base station to mobile station) may be provided that can carry the types of messages specified for current analog forward control channels (FOCCs), but in a format which allows an idle mobile station to read overhead messages when locking onto the FOCC and thereafter only when the information has changed; the mobile sleeps at all other times. In such a system, some types of messages are broadcast by the base stations more frequently than other types, and mobile stations need not read every message broadcast. The systems specified by the TIA/EIA/IS-54-B and TIA/EIA/IS-136 standards are circuit-switched technology, which is a type of "connection-oriented" communication that establishes a physical call connection and maintains that connection for as long as the communicating end-systems have data to exchange. The direct connection of a circuit switch serves as an open pipeline, permitting the end-systems to use the circuit for whatever they deem appropriate. While circuit-switched data communication may be well suited to constant-bandwidth applications, it is relatively inefficient for low-bandwidth and "bursty" applications. Packet-switched technology, which may be connection-oriented (e.g., X.25) or "connectionless" (e.g., the Internet Protocol, "IP"), does not require the set-up and tear-down of a physical connection, which is in marked contrast to circuit-switched technology. This reduces the data latency and increases the efficiency of a channel in handling relatively short, bursty, or interactive transactions. A connectionless packet-switched network distributes the routing functions to multiple routing sites, thereby avoiding possible traffic bottlenecks that could occur when using a central switching hub. Data is "packetized" with the appropriate end-system addressing and then transmitted in independent units along the data path. Intermediate systems, sometimes called "routers", stationed between the communicating end-systems make decisions about the most appropriate route to take on a per packet basis. Routing decisions are based on a number of characteristics, including: least-cost route or cost metric; capacity of the link; number of packets waiting for transmission; security requirements for the link; and intermediate system (node) operational status. Packet transmission along a route that takes into consideration path metrics, as opposed to a single circuit set up, offers application and communications flexibility. It is also how most standard local area networks (LANs) and wide area networks (WANs) have evolved in the corporate environment. Packet switching is appropriate for data communications because many of the applications and devices used, such as keyboard terminals, are interactive and transmit data in bursts. Instead of a channel being idle while a user inputs more data into the terminal or pauses to think about a problem, packet switching interleaves multiple transmissions from several terminals onto the channel. Packet data provides more network robustness due to path independence and the routers' ability to select alternative paths in the event of network node failure. Packet switching, therefore, allows for more efficient use of the network lines. Packet technology offers the option of billing the end user based on amount of data transmitted instead of connection time. If the end user's application has been designed to make efficient use of the air link, then the number of packets transmitted will be minimal. If each individual user's traffic is held to a minimum, then the service provider has effectively increased network capacity. Packet networks are usually designed and based on industry-wide data standards such as the open system interface (OSI) model or the TCP/IP protocol stack. These standards have been developed, whether formally or de facto, for many years, and the applications that use these protocols are readily available. The main objective of standards-based networks is to achieve interconnectivity with other networks. The Internet is today's most obvious example of such a standards-based network pursuit of this goal. Packet networks, like the Internet or a corporate LAN, are integral parts of today's business and communications environments. As mobile computing becomes pervasive in these environments, wireless service providers such as those using TIA/EIA/IS-136 are best positioned to provide access to these networks. Nevertheless, the data services provided by or proposed for cellular systems are generally based on the circuit-switched mode of operation, using a dedicated radio channel for each active mobile user. A few exceptions to data services for cellular systems based on the circuit-switched mode of operation are described in the following documents, which include the packet data concepts. U.S. Pat. No. 4,887,265 and "Packet Switching in Digital Cellular Systems", Proc. 38th IEEE Vehicular Technology Conf., pp. 414-418 (June 1988) describe a cellular system providing shared packet data radio channels, each one capable of accommodating multiple data calls. A mobile station requesting packet data service is assigned to a particular packet data channel using essentially regular cellular signalling. The system may include packet access points (PAPS) for interfacing with packet data networks. Each packet data radio channel is connected to one particular PAP and is thus capable of multiplexing data calls associated with that PAP. Handovers are initiated by the system in a manner that is largely similar to the handover used in the same system for voice calls. A new type of handover is added for those situations when the capacity of a packet channel is insufficient. These documents are data-call oriented and based on using system-initiated handover in a similar way as for regular voice calls. Applying these principles for providing general purpose packet data services in a TDMA cellular system would result in spectrum-efficiency and performance disadvantages. U.S. Pat. No. 4,916,691 describes a new packet mode cellular radio system architecture and a new procedure for routing (voice and/or data) packets to a mobile station. Base stations, public switches via trunk interface units, and a cellular control unit are linked together via a WAN. The routing procedure is based on mobile-station-initiated handovers and on adding to the header of any packet transmitted from a mobile station (during a call) an identifier of the base station through which the packet passes. In case of an extended period of time between subsequent user information packets from a mobile station, the mobile station may transmit extra control packets for the purpose of conveying cell location information. The cellular control unit is primarily involved at call establishment, when it assigns to the call a call control number. It then notifies the mobile station of the call control number and the trunk interface unit of the call control number and the identifier of the initial base station. During a call, packets are then routed directly between the trunk interface unit and the currently serving base station. The system described in U.S. Pat. No. 4,916,691 is not directly related to the specific problems of providing packet data services in TDMA cellular systems. "Packet Radio in GSM", European Telecommunications Standards Institute (ETSI) T Doc SMG 4 58/93 (Feb. 12, 1993) and "A General Packet Radio Service Proposed for GSM" presented during a seminar entitled "GSM in a Future Competitive Environment", Helsinki, Finland (Oct. 13, 1993) outline a possible packet access protocol for voice and data in GSM. These documents directly relate to TDMA cellular systems, i.e., GSM, and although they outline a possible organization of an optimized shared packet data channel, they do not deal with the aspects of integrating packet data channels in a total system solution. "Packet Data over GSM Network", T Doc SMG 1 238/93, ETSI (Sep. 28, 1993) describes a concept of providing packet data services in GSM based on first using regular GSM signalling and authentication to establish a virtual channel between a packet mobile station and an "agent" handling access to packet data services. With regular signalling modified for fast channel setup and release, regular traffic channels are then used for packet transfer. This document directly relates to TDMA cellular systems, but since the concept is based on using a "fast switching" version of existing GSM traffic channels, it has disadvantages in terms of spectrum efficiency and packet transfer delays (especially for short messages) compared to a concept based on optimized shared packet data channels. Cellular Digital Packet Data (CDPD) System Specification, Release 1.0 (July 1993), the disclosure of which is expressly incorporated here by reference, describes a concept for providing packet data services that utilizes available radio channels on current Advanced Mobile Phone Service (AMPS) systems, i.e., the North American analog cellular system. CDPD is a comprehensive, open specification endorsed by a group of U.S. cellular operators. Items covered include external interfaces, air link interfaces, services, network architecture, network management, and administration. The specified CDPD system is to a large extent based on an infrastructure that is independent of the existing AMPS infrastructure. Commonalities with AMPS systems are limited to utilization of the same type of radio frequency channels and the same base station sites (the base station used by CDPD may be new and CDPD specific) and employment of a signalling interface for coordinating channel assignments between the two systems. Routing a packet to a mobile station is based on, first, routing the packet to a home network node (home Mobile Data Intermediate System, MD-IS) equipped with a home location register (HLR) based on the mobile station address; then, when necessary, routing the packet to a visited, serving MD-IS based on HLR information; and finally transferring the packet from the serving MD-IS via the current base station, based on the mobile station reporting its cell location to its serving MD-IS. Although the CDPD System Specification is not directly related to the specific problems of providing packet data services in TDMA cellular systems that are addressed by this application, the network aspects and concepts described in the CDPD System Specification can be used as a basis for the network aspects needed for an air link protocol in accordance with this invention. The CDPD network is designed to be an extension of existing data communications networks and the AMPS cellular network. Existing connectionless network protocols may be used to access the CDPD network. Since the network is always considered to be evolving, it uses an open network design that allows the addition of new network layer protocols when appropriate. The CDPD network services and protocols are limited to the Network Layer of the OSI model and below. Doing so allows upper-layer protocols and applications development without changing the underlying CDPD network. From the mobile subscriber's perspective, the CDPD network is a wireless mobile extension of traditional networks, both data and voice. By using a CDPD service provider network's service, the subscriber is able seamlessly to access data applications, many of which may reside on traditional data networks. The CDPD system may be viewed as two interrelated service sets: CDPD network support services and CDPD network services. CDPD network support services perform duties necessary to maintain and administer the CDPD network. These services are: accounting server; network management system; message transfer server; and authentication server. These services are defined to permit interoperability among service providers. As the CDPD network evolves technically beyond its original AMPS infrastructure, it is anticipated that the support services shall remain unchanged. The functions of network support services are necessary for any mobile network and are independent of radio frequency (RF) technology. CDPD network services are data transfer services that allow subscribers to communicate with data applications. Additionally, one or both ends of the data communication may be mobile. To summarize, there is a need for a system providing general purpose packet data services in D-AMPS cellular systems, based on providing shared packet-data channels optimized for packet data. This application is directed to systems and methods that provide the combined advantages of a connection-oriented network like that specified by the TIA/EIA/IS-136 standard and a connectionless, packet data network. Furthermore, this invention is directed to accessing the CDPD network, for example, by existing connectionless network protocols with low complexity and high throughput. SUMMARY In accordance with one aspect of the invention, there is provided a method of supporting a plurality of mobile station operation modes in a wireless communication system which are selectable by user or other external control. Presently, communication protocols exist for supporting end user equipment which operates only in a single mode of operation. However, it is desirable to combine protocols from various technologies to form end user equipment which operates in multiple modes of operation. Thereby, the present method allows the mobile station to operate in a multi-mode environment where a user or external device can invoke one or more operational modes. BRIEF DESCRIPTION OF THE DRAWINGS The features and advantages of Applicants' invention will be understood by reading this description in conjunction with the drawings in which: FIG. 1 schematically illustrates pluralities of Layer 3 messages, Layer 2 frames, and Layer 1 channel bursts, or time slots; FIG. 2(a) shows a forward DCCH configured as a succession of time slots included in the consecutive time slots sent on a carrier frequency; FIG. 2(b) shows an example of an IS-136 DCCH field slot format; FIG. 3 illustrates an exemplary hierarchical, or multi-layered, cellular system; FIG. 4 is a block diagram of an exemplary cellular mobile radiotelephone system, including an exemplary base station and mobile station; FIGS. 5(a)-5(e) illustrate end-user equipment providing packet data functionality; FIG. 6 illustrates one example of a possible mapping sequence between various layers in a radiocommunication system; FIGS. 7(a)-7(e) illustrate examples of mobile station functional modes; and FIG. 7(f) illustrates one example of a telemetric device and a mobile station having a display device. DETAILED DESCRIPTION As described above, there are numerous technologies which support wireless data communication, including packet data. Of particular interest are D-AMPS (TIA/EIA/IS-136) and CDPD. By combining protocols from these two existing technologies with the functionality described in this application, new forms of end-user equipment can be identified. FIGS. 5(a)-5(e) illustrate examples of how the functionality of this application ("D-AMPS Packet Data") can be combined with other technologies into new end-user equipment. This invention is directed to implementing protocols and procedures for connectionless communication between the mobile station and the base station. In particular, the invention is directed to an air interface protocol and the associated mobile station procedures required for packet data that are based on IS-136. The protocol and procedures for one aspect of this invention resemble the digital control channel (DCCH) operation of IS-136 because IS-136 was designed to provide connectionless transmission of a point-to-point short message service on the DCCH. The IS-136 protocol and procedures have been expanded to support packet-oriented services in embodiments of Applicants' invention. More generally, the invention is directed to communication between a base station and network entities using any standardized or proprietary packet network or using a connection oriented protocol because no assumptions have been made about the network. The network aspect of the CDPD specification is one example that can be used in implementing this invention. In order to maximize the flexibility of performance characteristics and be able to tailor terminal implementation for specific applications in specific embodiments of the invention, several bandwidth allocations are provided. One such bandwidth allocation is hosted PDCH, which is an added logical subchannel on the IS-136 digital control channel. The hosted PDCH allows a minimal implementation effort but provides limited throughput rate. Three other bandwidth allocations provided on the dedicated PDCH are full-rate PDCH, double-rate PDCH and triple-rate PDCH. A PDCH can be mixed with IS-136 DCCHs and DTCs on the same carrier up to the rate limit corresponding to three full rate channels. The interested reader is directed to U.S. patent application Ser. No. 08/544,493, now U.S. Pat. No. 5,907,555, entitled "A Method for Compensating Time Dispersion in a Communication System," to Raith et al., filed on Oct. 18, 1995 and U.S. patent application Ser. No. 08/544,490, now U.S. Pat. No. 5,729,531, entitled "Bandwidth Allocation" to Raith et al., filed on Oct. 18, 1995, the disclosure of both applications being expressly incorporated here by reference. As illustrated in FIGS. 5(a) and 5(b), existing terminals may operate in either only the CDPD mode (FIG. 5(a)) or only the D-AMPS mode (FIG. 5(b)). However, the terminal may selectively operate in one or more of multiple modes as illustrated in FIGS. 5(c), 5(d), and 5(e) by implementing the protocol and procedures of this invention. For example, the terminal may support D-AMPS packet data only as illustrated in FIG. 5(c), D-AMPS (i.e., IS-136 voice and data) and D-AMPS packet data and CDPD as illustrated in FIG. 5(d) and D-AMPS and D-AMPS packet data as illustrated in FIG. 5(e). Additionally, the set of specifications also includes support for the asynchronous data, Group 3 facsimile (IS-130 and IS-135) and short message services which are not illustrated in FIGS. 5(a)-5(e). As a result, this invention combined with other technologies provide new end user equipment. The utility of equipment conforming to the invention can be viewed from a variety of perspectives. From the D-AMPs cellular/PCS operator perspective, the equipment can be efficiently deployed in both D-AMPs 800 MHz and PCS 1900 MHz. This mode of operation has channel-by-channel upgrade with no frequency guard band needed, a common packet data/D-AMPS radio resource management, PDCH bandwidth allocation on demand, and full flexibility in allocating PDCH among frequencies and time slots. In this mode of operation, no geographic guard zones are needed and an existing frequency plan can be maintained. Thereby, the cellular and packet data networks have a greater availability and are more seamless through intersystem paging. Also, a higher bandwidth efficiency (throughput/bandwidth) is provided than in the CDPD air interface and the existing CDPD infrastructure may be retained. From the perspective of an AMPS cellular operator, if DCCH functionality is provided, the same benefits as for a D-AMPS operator can be achieved by implementing this invention. From the perspective of the D-AMPS mobile station manufacturer, this invention has no RF circuit impact, and the hosted PDCH operation does not require new physical layers or Layer 2 development. Furthermore, the dedicated PDCH provides for higher throughput than the CDPD air interface and requires a minimum development effort regarding hardware. Also, an enhanced sleep mode is provided which has less battery drain than CDPD; improved efficiency of broadcast and simulcast transmission is provided; and a seamless cellular/packet data service is achieved. From the perspective of the D-AMPs base station manufacturer, no impact on the RF circuit, combining of circuits and antenna configuration occurs by implementing this invention. Also, the hosted PDCH operation does not require new physical layers or Layer 2 development and the dedicated PDCH requires a minimum development effort using IS-136 as a basis. From the perspective of the packet data network equipment manufacturer, the CDPD backbone and CDPD applications are not impacted by implementing this invention. From the perspective of the CDPD mobile station manufacturer, all higher layer protocols can be reused when implementing this invention. The protocol and procedures for connectionless communication between mobile stations and base stations in accordance with this invention are directed to maximizing performance characteristics. Other desirable expansions of functionality by this invention include introducing PDCH paging areas and registration, as per IS-136 for example, providing the option to send Layer 3 messages defined for connectionless communication on a connection-oriented DTC, providing for IS-136 paging indicators while on the PDCH and providing for dedicated PDCH notification while on a DTC. One possible set of specific protocol and procedures for enhancing aspects of various connectionless communication between mobile stations and base stations is discussed below. To aid in understanding, one exemplary mapping sequence is illustrated in FIG. 6. Beginning with a CDPD mobile data link protocol (MDLP) frame, a Layer 3 message, including a protocol discriminator (PD) and message type (MT) indicator, is mapped into several Layer 2 frames. The Layer 2 frame is further mapped onto an FPDCH time slot. Lastly, the mapping of FPDCH time slots onto a superframe is illustrated. The length of the forward PDCH (FPDCH) time slots and reverse PDCH (RPDCH) bursts are fixed; although there may be three forms of RPDCH bursts which have different fixed lengths. The FPDCH slot and the full-rate PDCH are assumed to be on the physical layer in FIG. 6. This description assumes the TDMA frame structure is that of the IS-136 DCCH and DTC. In the interest of maximal throughput when a multi-rate channel is used (double-rate PDCH and triple-rate PDCH), an additional FPDCH slot format is specified. Existing technologies such as D-AMPS and CDPD may be combined to provide multiple mode terminal functionality as illustrated in FIGS. 5(c), 5(d), and 5(e). The functionality for combining D-AMPS and CDPD technologies from a terminal and end user point-of-view will be described with reference to FIGS. 7(a), 7(b), 7(c), 7(d), and 7(e). In each of these figures, the selection of the mode of operation may be controlled by the user at every power-on event, by a default mode that has been stored in the terminal by the user or by an external device such as a computer or remotely monitored apparatus. FIG. 7(a) illustrates selecting only one of the plural modes of operation. For example, the user may want to activate the D-AMPS mode only, whereby the mobile station does not register itself on the PDCH system. The base station, MSC and interworking function (BMI) would then not be informed about the packet data capability of the mobile station. Alternatively, the packet-only mode may be activated by the user. Analogously, the mobile station need not then register with the IS-136 system. FIG. 7(a) illustrates the functional group selection which may be made by the user, by the stored default mode or by another external device which is linked to the radio terminal. FIG. 7(b) illustrates the selection of activating both D-AMPS and PDCH modes of operation. As illustrated by step 1 of FIG. 7(b), the mobile station finds a DCCH and reads the BCCH to find a pointer to a corresponding beacon PDCH. The beacon PDCH (the carrier frequency of one PDCH) is provided if the DCCH indicates support of one or more dedicated PDCHs. The mobile station registers itself on the beacon PDCH and may be assigned another dedicated PDCH by the base station, MSC and Interworking function (BMI) response. Once the mobile station is locked to its assigned PDCH, the mobile station enters an active mode and registers itself as represented by step 2. Once the PDCH registration is successfully completed or an irrecoverable error condition is detected, the mobile station returns to camp on the initial DCCH as represented at step 3. Accordingly, FIG. 7(b) illustrates the possibility of operating the mobile station as a voice and packet terminal by activating both D-AMPS and PDCH modes of operation in this example. FIG. 7(c) illustrates the mobile station activated as a packet only terminal. FIG. 7(c) illustrates one example where the PDCH mode of operation is only activated by the mobile station first finding a DCCH and reading the BCCH to find the pointer to the beacon PDCH as represented by step 1 of FIG. 7(c). The mobile station does not register itself on the DCCH at this time as it did in the previous example. For additional material related to beacon PDCH's, the interested reader should refer to U.S. patent application Ser. No. 08/544,488, now U.S. Pat. No. 5,768,267, entitled "A Method for System Registration and Cell Reselection" to Raith et al., which application was filed on Oct. 18, 1995 and which disclosure is expressly incorporated here by reference. Once the mobile station is locked to the beacon PDCH, the mobile station enters a CDPD active mode and registers itself as represented by step 2. The mobile station may be redirected to a different PDCH as a result of its BMI response to its registration. The mobile station stays in the active mode on the indicated PDCH until an active timer has expired as represented by step 3. The mobile station then enters a passive mode as represented by step 4. In this way, the mobile station is activated as a packet-only terminal at registration. For a complete discussion of the active timer described in the foregoing example and the passive time discussed in the following example, the interested reader is directed to U.S. patent application Ser. No. 08/544,838, now U.S. Pat. No. 5,806,007, entitled "Activity Control for a Mobile Station In a Wireless Communication System;" to Raith et al., which application is expressly incorporated here by reference. In FIG. 7(d), the mobile station is activated (i.e., has registered, as discussed above with respect to FIG. 7(a) in both the D-AMPS and PDCH mode of operation where the default mode of operation is D-AMPS. FIG. 7(d) is directed to a sequence of events which includes both a PDCH and D-AMPS page. When the mobile station is in the IS-136 sleep mode and a page message is received, which indicates a terminating PDCH transaction, (i.e., packet data is to be sent to the mobile) the mobile station moves to its previously assigned PDCH and enters an active mode as represented by step 1 of FIG. 7(d). After the terminating PDCH transaction is completed, and an activity timer has expired, the mobile station enters a CDPD passive mode as represented at step 2. After a second timer expires while in the passive mode, the mobile station returns to the initial DCCH as represented by step 3. When the mobile station is in an IS-136 sleep mode and a voice or IS-136 page is received, the mobile station is assigned a traffic channel for a voice call as represented by step 4. After completion of the voice call, the mobile station returns to the IS-136 sleep mode as represented by step 5. Accordingly, these functions allow the mobile station to be paged as either a voice or a packet data terminal. An example of a mobile station paged as a packet-only terminal is illustrated in FIG. 7(e). As represented at step 1 of FIG. 7(e), a page message is received indicating a terminating PDCH transaction. After the terminating PDCH transaction is completed, and the active timer expires without receiving additional packet data, the mobile station enters a passive mode as represented by step 2. The IS-136 active mode is not needed for a packet data-only terminal and this mode is unused as indicated in FIG. 7(e). The capability to read the BCCH on IS-136 is still required for a packet data only terminal and is indicated as such in FIG. 7(e) by the broken "X" across the IS-136 state. For example, the overhead information provided on the DCCH may be used as described in U.S. patent application Ser. No. 08/544,839, now U.S. Pat. No. 6,016,428, entitled "Registration Control of Mobile Stations in a Wireless Communication System," to Diachina et al., filed on Oct. 18, 1995, the disclosure of which is expressly incorporated here by reference. Accordingly, the mobile station functions as a packet data-only terminal. To facilitate the user control for the multiple modes of operation by the mobile station in this invention, user interaction techniques may be provided to control the multiple modes of operation. In one example of a user interaction technique, the user may acquire the availability of services and attributes of the mobile station by a known display 181 of the mobile station. The services and attributes, and especially the transmission rate, may be presented to the user on the display in any conventional display form, such as with icons, symbols, or text. Thereafter, the user may change the mode of operation for any amount of time and may also change the default mode of operation permanently. Accordingly, a large amount of control may be provided to the user for operating the mobile stations in multiple modes. The control for the multiple modes of operation by the mobile station in this invention may alternately be controlled by telemetry. In one example of a telemetric technique, data may be collected remotely from a computer 182 by a mobile station. In this case, the mobile station may send information on its services and attributes to the computer. Then, the computer may select the desired mode of operation based on the data to be collected and sent to the mobile station. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

A method and device are provided for of supporting a plurality of mobile station operation modes in a wireless communication system by user control. Presently, communication protocols exist for supporting end user equipment which operates in a single mode of operation. However, it is desirable to combine protocols from various technologies to form end user equipment which operates in multiple modes of operation. Thereby, the present method allows the mobile station to operate in a multi-mode environment where a user can invoke a certain mode.

BACKGROUND OF THE INVENTION Machine tools utilizing a rotating workpiece or a rotating spindle are often capable of permitting sequential tool operation on the workpiece. For instance, where the workpiece is rotating such as in lathes, turret lathes and chucking machines, a variety of tools such as boring tools, centers, drills and reamers may be mounted upon an indexable tool holder, such as a turret, for sequential engagement with the workpiece. In this manner a plurality of machining operations may be accomplished without tranfer of the workpiece to another station or rotating chuck or spindle, but the nature of the machining operations are limited. Machine tools utilizing rotating tools such as drills and boring bits, may be mounted upon rotatable spindles of the axially translatable type. Such tools normally require that the workpiece be retrieved from a supply, chucked into the workpiece holder, machined by the tools, unchucked, and placed in a bulk container for transfer to the next machine tool. Such extensive multiple handling of the workpiece is expensive and time consuming, and makes it difficult to insure high accuracy and quality. Conventional machine tools do not permit the ready machining of opposite sides of a workpiece. For instance, workpieces such as hubs, blanks and gears often require turning and drilling operations on opposite sides thereof, and such operations require that the workpiece be chucked, machined, unchucked and then transported to another machine wherein the workpiece opposite side is chucked permitting machining of the side not previously accessible. The operations on opposite sides of the part have required two separate machines and two chuckings. It is an object of the invention to provide a machine tool of the automated type wherein the workpiece is sequentially transferred from one work station to another, each station utilizing a linearly displaceable rotating work-holding spindle wherein sequential operations may be automatically achieved upon a common workpiece. Another object of the invention is to provide a machine tool having a base and a transfer region defined thereon wherein workpieces are sequentially transferred between adjacent aligned rotating spindles permitting sequential secondary operations to be automatically performed on the workpiece. A further object of the invention is to provide a machine tool of the multiple spindle type wherein the base of the machine tool includes a central region and lateral sides disposed on opposite sides of the transfer central region. Tools located on opposite sides of the central region permit the workpiece to be automatically sequentially machined on opposite sides thereby minimizing handling and material flow problems. In the practice of the invention, a machine tool includes a heavy base having a central region and lateral sides located on opposite sides of the central region. In most cases, the base will be of an elongated configuration, and preferably, the base includes a plurality of laterally extending portions having a length perpendicularly disposed to the length of the central region. A plurality of work-holding spindles are mounted upon the base lateral sides, a single spindle usually being located upon each lateral portion, and preferably, spindles are located upon each base lateral side with respect to the central region. The spindles consist of elongated tubular heads mounted to be displaceable in their longitudinal direction, and each head usually includes a rotating work-holding spindle powered by an electric motor. However, non-rotating spindles may also be used at selected locations. Longitudinal displacement of the spindles is provided by a linear actuator, such as a threaded shaft or rod rotated by an electric motor. Work-holding means are mounted upon one end of the spindle, while torque transmitting means are defined upon the other spindle end in operative engagement with the spindle drive motor. The heads move in a direction substantially perpendicular to the length of the machine tool base central region, and work transfer apparatus is mounted upon the base central region for sequentially transferring workpieces between adjacent spindles. Preferably, the transfer means includes a plurality of work-holding blocks reciprocal between alignment with adjacent spindles in the direction of the central region length. As the spindles are mounted upon opposite sides of the workpiece transfer apparatus, the workpieces may be machined upon opposite sides by tools located adjacent the spindles as they are transferred between adjacent spindles, and the workpiece is sequentially transferred along the length of the machine tool central region to complete the desired operations. The work transfer apparatus includes an elongated beam suspended above the base central region, and the workpiece blocks suspend below this beam whereby the blocks may be readily aligned with the spindles. Reciprocal motor means, such as of the hydraulic or screw actuator type, are used to reciprocate the beam and workpiece holders. The apparatus of the invention permits a series of machining operations to be produced on a workpiece, the operation of the machine tool is fully automated, and the concise configuration of the machine tool and the rapid sequential machining operations permits relatively complex machining to be rapidly produced. BRIEF DESCRIPTION OF THE DRAWINGS The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein: FIG. 1 is a perspective view of a machine tool in accord with the invention, FIG. 2 is a plan view of the machine tool of FIG. 1, FIG. 3 is an elevational, partially sectional view of a typical spindle assembly utilized with the machine tool of the invention, and FIG. 4 is an elevational, sectional view as taken along Section IV--IV of FIG. 3. DESCRIPTION OF THE PREFERRED EMBODIMENT The overall arrangement of a machine tool in accord with the concept of the invention will be appreciated from FIGS. 1 and 2. The machine tool includes a base frame generally indicated at 10 which is of an elongated configuration as appreciated from FIG. 2, and includes a central region portion 12 of a rectangular configuration and lateral portions 14 are disposed upon opposite sides of the central region. The base is preferably formed of heavy fabricated or cast components, as is common in the machine tool art, and the frame may include access openings and the like for chip removal as is common. The frame lateral portions 14 are each of a generally rectangular configuration having a length perpendicularly disposed to the length of the central region 12, and the location of the lateral portions with respect to the length of the central region is determined by the operations that are to be performed on the machine tool, and the number of work-holding spindles to be located upon each side of the central region. Each frame lateral portion 14 serves as the support for a work-holding spindle assembly 16. Basically, each spindle assembly includes a rotating spindle having a workpiece holder located upon the inner end, and a spindle drive is associated with the outer end. Means are provided for axially translating the rotating spindle to feed the spindle into the transfer apparatus and provide the necessary workpiece pickup and movement. It will be appreciated that the specific arrangement of the spindle may take various forms. For instance, the location of the spindle electric drive motor may be above or below the spindle, and likewise, the means for translating the spindle may be located above or below the spindle axis. FIGS. 3 and 4 illustrate a typical spindle assembly, and for purpose of illustration, the arrangement is one wherein the spindle linear actuator is located below the spindle, and the drive motor for the spindle is located above the spindle axis. Each frame lateral portion 14, at its upper region, includes a guideway system which supports an elongated head 18. As will be appreciated from FIG. 3, the guideway system includes anti-friction bearings 20 which support the rectangular head 18 for linear displacement along its length. Of course, the head bearing system must very accurately support the head throughout its axial movement, and the linear actuator for axially translating the head is described below. Internally, the head 18 supports the rotating shaft 22 and its portion 23 constituting the spindle. The spindle 22 is rotatably supported within the head 18 upon axially spaced bearings 24 wherein the spindle accurately rotates within the head and is axially displaceable therewith. The outer end of the spindle includes a drive pulley 26 keyed thereto which is belted to an electric drive motor 28, located within the motor housing 30, FIG. 1. The inner end of the spindle 22 includes work-holding and chucking structure 32 conforming to the workpiece which may be of a conventional configuration and forms no part of the present invention. The work-holding apparatus is automatically operable by electric air or hydraulic actuators, not shown, as is well known in the work-holding art. Linear displacement of head 18 and advancement of the spindle 22, is achieved by a linear actuator. Such an actuator could be of the hydraulic or electric type, and in the disclosed embodiment comprises an electrically driven threaded shaft. As will be appreciated from FIG. 3, a threaded shaft 34 is rotatably mounted within bearing housings 36 fixed upon the guide structure for the head 18. The shaft 34 is restrained against axial thrust, and the head guide includes a slot 38 thorugh which the nut block 40 extends which is attached to the head 18. The nut block 40 includes a ball-nut 42 containing movable balls engaging the complementary threads or grooves of the threaded shaft 34 wherein a low friction ball-nut and screw arrangement of the known type is produced. Rotation of the shaft 34 is through the variable speed electric motor 44 and a step-down transmission 46 wherein selective rotation of the shaft 34 in either direction is produced and shaft rotation axially displaces the head 18 and spindle 22 during rapid and slow traverse, extended and retracted cycles. As will be appreciated from FIGS. 1 and 2, a plurality of base lateral portions 14 and spindle assemblies are utilized with a machine tool in accord with the invention, the number being determined by the types of operations that are to be performed by the machine. Usually, spindle assemblies 16 will be located upon opposite sides of the frame central region 12, and such location of the spindles permits the workpiece to be approached from opposite sides permitting machining of the workpiece on both sides or opposite ends. Movement of the workpiece from one workpiece spindle to another is achieved by transfer apparatus 48 located on the base central region 12. While the transfer mechanism could take a variety of forms, a preferred embodiment is that illustrated wherein the transfer apparatus is elevated with respect to the central region. In this form, the transfer apparatus includes an elongated beam 50, broken for purpose of illustration in FIG. 1, supported above the central region upon guide columns 52 attached to the central region. A plurality of workpiece carriers 54 depend from below the beam 50 and move with the beam. The beam 50 is slidably supported on the columns 52 by bearings 55 and is longitudinally reciprocal by motor and drive means 56 under an automatic control 57. The motor and drive 56 may be hydraulic, air or electrically operated. Each workpiece carrier 54 is provided with chucking structure 58 which may be of a conventional form designed to conform to the workpiece for grasping the workpiece and holding the same during the transfer cycle. After being worked upon at each spindle location, the workpiece is transferred to an aligned carrier 54 and the beam 50 "shifts" along its length which moves the carrier 54 for alignment with the adjacent spindle assembly 16 thereby transferring the workpiece to the next spindle. The beam and workpiece carriers are returned to alignment after machining with the spindle with which they were previously aligned and are then ready to accept the next workpiece therefrom. Thus, it will be appreciated that it is only necessary for the beam workpiece carriers to shift a distance equal to the separation of adjacent spindle assemblies between cycles. The "first" workpiece carrier 54 on the beam 50 will receive the workpiece from automatic or manual loading means, not shown, and the "last" workpiece carrier on the beam will transfer the completed workpiece to a position accessible to automatic or manual workpiece transfer apparatus. As best appreciated from FIGS. 1 and 2, a plurality of tool systems 60 are mounted upon lateral portions 14 adjacent the central region 12 for machining the workpiece while it is held by the adjacent spindle. The tool systems 60 include a variety of conventional turning and boring tools, drills, taps, reamers and the like may be mounted upon the central region 12 upon slides 62 and operated by motors 64 to permit secondary operations at each tool spindle location of the type desired. In operation, the workpieces within workpiece carriers 54 will be aligned with a spindle assembly 16. Energizing of the motor 44 will axially translate the head 18 toward the aligned carrier 54 permitting the chuck 32 to engage the workpiece, and firmly grasp the workpiece. Of course, at such time the carrier chuck 58 releases the piece to be machined. The motor 44 is then reversed to retract the head 18 and spindle 22, and this retraction is sufficient to align the chucked workpiece with the tool system 60 associated with that particular spindle assembly. Assuming that the workpiece is to be rotated during machining by the associated tool system 60, the associated motor 28 is energized to rotate the spindle 22 and chucked workpiece, and the associated tools 60 are automatically translated upon their slide 62 to produce the desired machining. After machining is completed, the tools 60 are withdrawn from the workpiece, the motor 44 is energized to extend the head 18 and place the workpiece into an aligned workpiece carrier 54 which has been brought into alignment with the spindle assembly after transferring the workpiece thereto initially. As previously mentioned, the fact that spindle assemblies 16 are mounted upon opposite sides of the central region 12 permits the workpiece to be machined on opposite sides without reversing the workpiece. Thus, workpiece handling is simplified without a sacrifice in accuracy. Minimizing the number of chucking operations of the workpiece contributes to the accuracy of the machining and by locating spindles upon opposite sides of the central region, high accuracies on both sides of the workpiece may be readily achieved. It is to be understood that with some types of machine operations, such a lateral drilling, boring, broaching, tapping, etc., the workpiece must be held stationary, and in such instances the spindle shaft 22 will not be rotated by motor 28, but will be locked against rotation. The head 18 and spindle 22 will be axially translated toward and from the aligned work carrier 54 to pick up the workpiece and draw it back into position for alignment with the associated tool system 60 and will return the workpiece to a carrier 54 after machining, all without spindle rotation. Control apparatus, such as housed in control box 57, is used to automatically sequence the operations and functions of the machine tool in accord with the invention, and as conventional control apparatus may be used, the same does not form a part of the present invention. Such control apparatus uses conventional limit switches, position sensors and the like commonly used in the machine tool art to control rapid and slow traverses, tool feeds, retraction cycles, and the like. Likewise, the operation of the movement of the beam 50 and workpiece carriers 54 is fully automated and coordinated with the spindle operation so that sequential movement of the workpiece from spindle to spindle is automatically and efficiently achieved. A machine tool in accord with the invention is capable of performing a series of machine operations on a workpiece in an automated manner wherein high production and low cost may be achieved in conjunction with superior quality and accuracy. It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention.

The invention pertains to a multiple spindle machine tool wherein a plurality of substantially parallel spindles transversely disposed to a workpiece transfer path permit sequential operations upon a workpiece transferred from spindle to spindle. Spindles may be mounted upon opposite sides of the transfer path permitting machining on opposite sides of a workpiece, and the machine tool permits successive operations to be performed sequentially, rapidly and economically.

The present invention relates to stable alcohol-containing, cream-based beverages. For purposes of the present application, the term "cream-based" includes a variety of dairy products broadly, including low-fat milk, milk, cream, half-and-half, and heavy cream. Broadly, any composition having more than 2% butterfat plus milk solids is within the scope of the term "cream-based", for purposes of the present application, although the present invention is particularly useful with heavy cream-based beverages which also contain alcohol. Heavy cream has about 40% butterfat. Also for purposes of the present application, the term "stable" refers to emulsion stability against breaking of the emulsion. Products prepared according to the present invention have an emulsion shelf stability for up to eighteen months or longer under normal storage conditions (room temperature storage). BACKGROUND OF THE PRESENT INVENTION It is well known to prepare alcoholic drinks using an alcoholic beverage or liqueur and adding milk or cream to it. Typical such drinks are milk punch, an Alexander, Pink Squirrel, Golden Cadillac, Irish Alexander, Amareto Cream, and Grasshopper. These drinks are usually prepared at home or at a bar for immediate consumption. Thorough mixing is accomplished by shaking the drink in a shaker, but if the drink is allowed to stand for a period of time, for instance one half hour, separation is likely to occur, developing separate fat and water phases, rendering the drink impalatable. Cream or milk-based, alcohol-containing drinks are becoming more popular, cream or milk by many being considered a restorer of good health. It would be convenient for consumers of such drinks to be able to purchase them in a premixed, packaged, stable emulsion form. Because of the presence of the alcohol and a large amount of sugar, even refrigeration may not be necessary to prevent spoilage. The availability of premixed, purchasable cream-based drinks is particularly desirable where such drinks have to be made in relatively large quantities, for instance at parties. Also, many of such cream-based alcohol-containing drinks are somewhat complicated to make and require a fair amount of time, which the host may not have. Some liquor stores offer bottled eggnog complete with liquor, the liquor preventing non-alcoholic ingredients in the eggnog from spoiling. The emulsion stability of eggnog emulsions is accomplished by the presence of the eggs, and is due in part to the high viscosity of the emulsions. There are also on the market packaged, alcohol-containing drinks made using non-dairy creamers. Non-dairy creamers are engineered food products, a typical such creamer containing a vegetable fat, a sweetening agent such as corn syrup solids, a protein such as sodium casinate, an emulsifier such as a mono- diglyceride, and a gum stabilizer, all in predetermined proportions. All of the ingredients are relatively pure in composition and their properties are well known, alone and in the combination. It is thus possible to predict the proportions necessary and use of whatever additional ingredients are necessary to make an alcohol-containing such creamer shelf stable. There is also on the market a product known as Bailey's Irish Cream, prepared from heavy cream, alcohol, sugar and coffee flavor. Aside from the above ingredients, the composition is secret and it is not known how shelf stability of the product is obtained. U.S. Pat. No. 3,486,906 to Todd, Jr., describes the use of non-ionic emulsifiers such as polyoxyethylene ethers of mixed partial oleic esters of sorbitol anhydrides, including polysorbate 80 and the like, mixed with a flavoring ingredient and added to beer. However, the patent points out that such emulsifiers were found to be not stable in beer and soon produced a highly unpalatable flavor. U.S. Pat. No. 4,093,750 describes the use of polyglycerol esters in citrus flavored beverages, replacing brominated oils or gum acacia for emulsion stability, and also to provide a cloud to give the drinks a desirable appearance. There is no reference in this patent to the use of these agents in alcohol-containing beverages. BRIEF DESCRIPTION OF THE PRESENT INVENTION The present invention resides in a homogenized cream/alcohol-containing beverage comprising cream or milk and alcohol in drink preparation amounts, and a high HLB emulsifier selected from the group consisting of high HLB polyglycerol esters of fatty acids, ethoxylated fatty acid esters; and sugar esters, each in an emulsifying amount. The cream (or milk) and alcohol are present in major amounts, as distinguished from beverages containing flavor compositions, e.g., essential oils, where a small amount of alcohol carrier may be employed for such compositions. Natural cream and milk emulsions are very complicated. There are no pure systems in the compositions. Even tap water, which may be used in making the emulsion, contains certain salts which will affect emulsion stability. The proteins which are present, other salts, sugars, flavors and colors, and the emulsion pH, all will have an effect on the emulsion stability. Further, concentrations will vary from batch to batch because of the use of natural cream or milk. These complications are further compounded by the presence of the alcohol which is known to break or have an adverse effect on fat/water emulsions. Thus, it was a surprising and fortuitous discovery to find a limited group of emulsifiers capable of stabilizing such alcohol/cream or milk beverages for prolonged periods of time. By alcohol, it is meant ethyl alcohol, the traditional alcohol employed in alcoholic beverages. A typical beverage within the scope of the present invention is one that is 34 proof, is homogenized and contains about 17% alcohol, about 14% fat (from heavy cream), plus flavorings and colorants in addition to an emulsifying amount of an emulsifier selected from the group stated above. A particularly preferred emulsifier is octaglycerol monostearate marketed by SCM Corporation under the trademark "Santone 8-1-S". It was found that this emulsifier, of the many investigated, was by far the best in stabilizing, for many months, a cream-based, alcohol-containing beverage, the cream being 40% butterfat heavy cream, against detectable phase separation. Even shaking, after months of storage, was not necessary prior to consumption. DETAILED DESCRIPTION OF THE INVENTION Whereas a large number of emulsifiers are available on the market today and are approved for food uses, only a limited number of emulsifiers are operable in the present invention. There is no particular pattern as to which emulsifiers are operable and which are not, except that those that are operable have high HLB values (more than about 10), preferably about 10 to about 16. The class of ethoxylated fatty acid esters useful in the present invention are the ethoxylated fatty acid esters of glycerol, hexitol, hexitan and isohexide, as well as the fatty acid esters of ethoxylated glycerol, hexitol, hexitan and isohexide. Sorbitol is a typical hexitol. One specific class of such compounds for use in the beverage of the present invention are the ethoxylated mono- diglycerides, which are the polyethoxylated fatty acid esters of glycerol, and may be conventionally described as a mixture of stearate, palmitate, and lesser amounts of myristate partial esters of glycerin condensed with about 18 to 22 moles, preferably about 20 moles, of ethylene oxide per mole of alpha-monoglyceride reaction mixture such as set forth in The Food Codex and FDA Regulations, 21 CFR 121.1221, and more particularly as set forth in the Egan patent, U.S. Pat. No. 3,433,645, incorporated herein by reference. The fatty acid radicals of ethoxylated monoglycerides broadly are higher fatty acid chains having about 12 to 18 carbon atoms. One suitable ethoxylated mono- diglyceride that may be employed in the present invention is Durfax-EOM (trademark) marketed by Durkee Foods Division of SCM Corporation. This emulsifier is manufactured from hydrogenated vegetable oils and has an HLB value of about 13, is fluid at ambient temperature, has an acid value maximum of 2.0, a hydroxyl value of 60-80, a saponification value of 65-75 and an oxyethylene content of 60.5-65.0%. Other ethoxylated fatty acid esters which may be employed in the present invention are the polysorbates, such as polyoxyethylene (20) sorbitan monostearate (polysorbate 60) or polyoxyethylene (20) sorbitan monooleate (polysorbate 80). These emulsifiers are sold under the trademarks "Durfax 60" and "Durfax 80", respectively, by Durkee Foods Division of SCM Corporation. They have an HLB value of about 13-16 and are fluid at ambient temperature. Ethoxylated mono- diglycerides may be prepared by reacting ethylene oxide with a mono- diglyceride mixture at temperatures of about 125° C., such as suggested in the Egan patent, U.S. Pat. No. 3,490,918, and incorporated herein by reference. Similar known procedures are available for the preparation of the polysorbates. Preferred compounds for use in the formulations of the present invention are the high HLB polyglycerol esters having HLB values ranging from 10 to 16. These esters are generally a mixture of monounsaturated and saturated fatty acid esters of a mixture of polyglycerols in which the range of polyglycerol is from octaglycerol to decaglycerol, with one or two fatty acyl ester groups per molecule. The monounsaturated and saturated fatty acids contain 16 to 18 carbon atoms and are typically derived from corn oil, cottonseed oil, lard, palm oil, peanut oil, safflower oil, sesame oil, soybean oil, tallow, and tall oil and the fatty acids derived from these substances may be either hydrogenated or unhydrogenated. The polyglycerol mixture is prepared by the polymerization of glycerol with an alkaline catalyst as exemplified in U.S. Pat. No. 3,637,774, or an acid catalyst as exemplified in U.S. Pat. No. 3,968,169. Polyglycerol esters are obtained by then esterifying the polyglycerol by reaction with fatty acids in direct esterification or by reaction with fats and oils in an interesterification process. Suitable polyglycerol esters broadly have a hydroxyl value of about 400 to 600, a saponification number of about 60 to 100, and acid values of less than about 10. The range of possible polyglycerol esters is small and can range from a monoesterified octaglycerol to a diesterified decaglycerol, with the iodine value of the fatty acid ranging from 0 to 90. A particularly suitable polyglycerol ester of fatty acids useful in the process of the present invention is octaglycerol monostearate (8-1-S). This compound has a calculated HLB value of about 13 and is of solid or plastic consistency at ambient temperature, having a Mettler Dropping Point of about 52°-57° C. Octaglycerol monostearate typically contains about 60-68% stearic acid and has a hydroxyl number of 500-570, a saponification number of 77-88, an acid number of under 5, and an IV of about 65-85. Another suitable polyglycerol ester of fatty acids useful in the process of the present invention is octaglycerol monooleate (8-1-0). This compound has a calculated HLB value of about 13-16 and is of fluid consistency at ambient temperature. Octaglycerol monooleate typically contains about 60-68% oleic acid and has a hydroxyl number of 500-570, a saponification number of 68-85 and an acid number of under 4.1. Still another suitable polyglycerol ester is decaglycerol distearate. The sugar esters and processes for making them are disclosed in a number of prior patents including the Sugar Research Foundation, Inc. patents to Hass, U.S. Pat. Nos. 2,893,990 and 2,970,142; the State of Nebraska patents to Osipow et al., U.S. Pat. Nos. 3,480,616 and 3,644,333; and Dai-Ichikogyo Seiyaku Co., Ltd. U.S. Pat. No. 3,792,041. One particularly suitable sugar ester is OW-1570 (trademark) manufactured by Ryoto Company of Japan. This emulsifier can be characterized as sucrose monooleate with 70% monoester. It has a fatty acid composition of approximately 60% oleic acid, and is fluid with a 60% water content. Its HLB value is about 15. Because of the presence of the alcohol, an emulsifying amount or usage level of emulsifier required is relatively high, on the order of about 0.14% to about 0.7% by weight, based on the entire weight of the alcohol/fat/water emulsion (or about 1.4 grams per liter to about 7 grams per liter, on a weight/volume basis). At upper usage levels, the ethoxylated mono- diglycerides and polysorbates (which both have detectable flavors) are likely to adversely affect the beverage flavor, making the polyglycerol esters preferred emulsifiers. Also, the polysorbates and ethoxylated mono- and diglycerides are unsaturated compounds, tending to make them subject to spoilage. The polyglycerol ester compound 8-1-S is substantially fully saturated, making this compound very stable in the presence of oxygen. The sugar esters are presently not food approved in the United States. In cream-containing beverages (40% butterfat in the dairy phase), the octaglycerol monostearate, being solid in consistency, offers the best results and, again, is preferred. Broadly, the beverage formulations of the present invention will be made with milk or cream and then will be kept refrigerated until consumption, to prevent spoiling, although the presence of the alcohol and sugar may make this unnecessary, particularly where the amount of alcohol employed is relatively high. Milk and cream are traditional ingredients in milk or cream-containing alcoholic beverages, and the purpose of the present invention, in part, is to duplicate such beverages. In beverages containing relatively low amounts of alcohol and/or sugar, particularly at lower levels of sugar and alcohol, refrigeration may be necessary. The present invention is particularly useful with heavy cream-containing beverages which are 34 proof (having about 17% alcohol). With the emulsifiers of the present invention, particularly octaglycerol monostearate (8-1-S), the beverages are extremely stable against phase separation and also are stable against spoilage. Typically, the heavy cream will be present at a level of about 30-40%. Heavy cream is about 40% butterfat, giving the composition of this embodiment of the present invention a fat content of about 12-16%. In the beverages of the present invention, the sugar content can vary substantially, depending upon taste. Typically, it will be about 20-30% basis of the entire weight of the emulsion. The beverages of the present invention can contain many other ingredients than those mentioned above, for instance flavoring (both natural and synthetic), colorants, gum stabilizers, other polysaccharides such as starch, other carbohydrates such as corn syrup solids, and egg or egg-derived products. In all cases, the balance of the formulation, after establishing levels of the above functional ingredients, is water. As the carbohydrate, there can be used corn syrups with D. E. values of 24 to 70 or higher, molasses, maltose, ribose, galactose, xylose, arabinose, honey, lactose, sucrose, dextrin, water soluble starch, pregelatinized starch, gum arabic, larch gum arabinogalactan, d-glucose, modified starches of the type set forth in Schoch U.S. Pat. No. 2,876,160, e.g., hypochlorite-oxidized cornstarch, torrefaction or roasted dextrins, etherified starches including hydroxyethyl, hydroxypropyl, methyl and ethyl derivatives, starch esters, e.g., starch acetate and starch sulfonate, waxy maize starch, waxy sorghum starch, and converted starches having a D. E. value of 4 to 20. Colloidal carbohydrate stabilizers include cellulose ethers such as methyl cellulose, e.g., the product marketed under the trademark "Methocel MC" (dimethyl ether of cellulose having 1.64-1.92 methoxy groups per glucose unit), mixed methyl hydropropyl cellulose, e.g., the product marketed under the trademark "methocel 90 HG" (an etherified cellulose having 1.08-1.42 methoxy groups and 0.1-0.3 hydroxypropyl groups per glucose unit) and the product marketed under the trademark "Methocel 65 HG" (an etherified cellulose having 1.61-1.75 methoxy groups and 0.1-0.18 hydroxypropyl groups per glucose unit), carboxymethyl cellulose, low methoxy pectin, i.e., pectin having a methoxy content of 2.5-4.5%, inulin, guar, Irish moss (carragheen), sodium alginate, gum tragacanth, gum karaya and locust bean gum. The beverages of the present invention are pasteurized in conventional fashion, e.g., at 140°-165° F. for 35 minutes to one hour, usually 155°-160° F., for 35 minutes. The beverages are then homogenized in conventional fashion to a particle size between 1 to 10 microns. For many uses the particle size of the emulsified material is not over 5 microns; and preferably in preparing the alcohol products of the present invention, particularly heavy cream-containing products, the particle size is reduced to less than about 3 microns, preferably about 1 to 1.5 microns. Homogenization is carried out in one or two stages at about the pasteurization temperature and at pressures which can vary from 500 psi to 5,000 psi, or somewhat higher. After homogenization, the beverages are cooled and packaged. They remained stable, showing neither spoilage nor phase separation for a prolonged period, even when stored at room temperature. In the following example and claims, all percentages are on a weight basis, based on the total weight of the beverage unless otherwise specified. EXAMPLE The following formula and process yielded a stable emulsion: ______________________________________Ingredients Weight Percent (Approx.)______________________________________Heavy cream (40% fat) 36Alcohol to yield 34 proofSugar 24-26%Water BalanceSantone 8-1-S flakes 2-10 grams/1,000 mls______________________________________ The ingredients were added to a mixing boat and mixed and pasteurized at about 155° F., after which they were homogenized in a two-stage homogenizer at pressures of about 3,500 psi and 500 psi to produce a particle size of about 1-1.5 microns. In this example, the Santone 8-1-S is in flake form, making it easy to use. It is normally very sticky and difficult to use, but by combining it with a carrier such as stearine (in this example, an inert ingredient) in the ratio of about 70% 8-1-S to about 30% stearine, a dry, non-sticky, flake form is obtained. The actual amount of 8-1-S present in the above formula is thus about 1.4 to 7 grams per liter, or on a percentage weight basis, about 0.14 to 0.7 percent. Optimum results were obtained with about 0.6% flakes, or about 0.42% 8-1-S.

An homogenized cream/alcohol-containing beverage comprising cream or milk and alcohol in drink preparation amounts, and a high HLB emulsifier selected from the group consisting of high HLB polyglycerol esters of fatty acids, ethoxylated fatty acid esters; and sugar esters, each in an emulsifying amount.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a non-provisional application which claims benefit under 35 USC §119(e) to U.S. Provisional Application Ser. No. 61/421,509 filed Dec. 9, 2010, entitled “CONDENSATION OF GLYCOLS TO PRODUCE BIOFUELS,” which is incorporated herein in its entirety. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT None. FIELD OF THE INVENTION The present disclosure relates to the field of biomass-derived transportation fuels. More specifically, it relates to methods for converting light glycol feeds originating from biomass into polyglycol products suitable for use as a bio-derived fuel or cetane-enhancing fuel additive. BACKGROUND There is a great interest in the discovery of alternative sources of fuels and chemicals from resources other than petroleum. Development of non-petroleum-based liquid transportation fuels may provide economic and environmental benefits, while also increasing national security by decreasing reliance on non-domestic energy sources. Biomass, such as plants and animal fats, represent a major alternative source of hydrocarbons that can be converted into fuels. Liquid fuels derived from biomass are rapidly entering the market, driven by both need for increased national energy independence and rapid fluctuations in the cost of petroleum products. In 2007, the Energy Independence and Security Act was passed in the United States, which requires increasing quantities of bio-derived fuels to be produced over time. Similarly, the European Union directive 2003/30/EC promotes the use of biofuels or other renewable fuels. The directive has set a minimum percentage of biofuels to replace diesel or gasoline for transport purposes so, that by the end of 2010 there should be a 5.75% minimum proportion of biofuels in all gasoline and diesel fuels sold. To meet these mandates, it is essential to develop more efficient processes to convert bio-derived compounds into fuels that can fulfill these government mandates, as well as future global energy needs. The carbohydrates found in plants and animals can be used to produce fuel range hydrocarbons. However, many carbohydrates (e.g., starch) are undesirable as feed stocks for creating biomass-derived fuels due to the costs associated with converting them to a useable form. The chemical structure of some carbohydrates makes them difficult to convert, and conversion processes may produce low yields of desirable products. Carbohydrates that are difficult to convert include compounds with low effective hydrogen to carbon ratios, including carbohydrates such as starches and sugars, and other oxygenates with low effective hydrogen including carboxylic acids and anhydrides, light glycols, glycerin and other polyols and short chain aldehydes. As such, development of an efficient and inexpensive process for converting one or more of these difficult-to-convert biomass feedstocks into a form suitable for use as a fuel additive could be a significant contribution to the art and to the economy. Glycerol is a significant side-product of the trans-esterification reaction utilized to convert plant oils and animal fats into biofuels, and some work has been done examining ways to utilize glycerol. Karinen, et al. have reported methods for the etherification of glycerol and isobutene, while papers by Frustieri, et al. and Keplacova, et al., both include methods for catalytic etherification of glycerol by tert-butyl alcohol. U.S. Patent App. Pub. US2010/0094062 describes a process for the etherification of glycerol with an alkene or alkyne, followed by nitration of a remaining hydroxyl group. A portion of the process claimed in US2008/0300435 pertains to the dimerization/condensation of alcohols such as pentanol or isopropyl alcohol. However, to date, no methods have demonstrated an efficient process for the etherification of biologically-derived light glycol feedstock, such as ethylene glycol or propylene glycol, that results in a product suitable for subsequent use as a fuel additive. BRIEF SUMMARY Towards this goal, we disclose herein a novel process for efficiently converting biomass-derived light glycols, such as ethylene glycol and propylene glycol, into low molecular weight poly-glycol products useful as oxygenated cetane enhancers in transportation fuels. Whereas glycerol is a common byproduct of transesterification processes, light glycol streams are often obtained by the moderate hydrogenolysis of larger biomass-derived oxygenates such as alditols, cleaving backbone carbon-carbon linkages to form this feed. Glycols are easier to utilize as feedstock than their parent alditols in that glycols are liquids at room temperature and may be distilled to remove impurities rather than having to rely on other purification techniques (e.g. ion-exchange for metals removal). In contrast, alditols in the five to six carbon range are solids at room temperature and tend to decompose when heated above their melting points. Unlike some unsaturated biomass derived oxygenates, glycols are stable and may be stored long term without special measures to prevent degradation. Unfortunately, glycols are not suitable for direct blending into fuels due to miscibility issues. However, converting these glycols to low molecular weight poly-glycols (LMWPG) helps resolve this problem. During the conventional processing of hydrocarbons to produce fuels, removing oxygen involves reacting oxygen containing compounds with hydrogen to produce water. However, the underlying chemistry behind the conversion of the present disclosure involves acid-catalyzed condensation reactions that do not require hydrogen for oxygen removal. This reduces greenhouse gas emissions while also reducing the operational cost associated with production of hydrogen. Some oxygen from the feed is left in the final product resulting in the product maintaining much of the volume of the original starting material. Finally, these condensation reactions may be conducted at much lower temperatures than conventional oxygen removal processes, resulting in further savings. The present disclosure pertains to using solid acidic catalysts to convert biomass-derived glycols into di-, tri-, and some larger low molecular weight polyglycols (LMWPG), followed by steps to increase miscibility of the LMWPG with liquid hydrocarbon fuels. Derivatives of these LMWPG fall into a category of materials termed oxygenated cetane improvers, which are larger, predominantly linear compounds with oxygen substituted for carbon periodically along the backbone. The oxygen content of oxygenated cetane improvers varies depending on the feedstream used in their formation. However, a National Renewable Energy Laboratory report by Murphy, et al. shows that number of polyglycols have been calculated to possess a high cetane number. In addition, preliminary findings by Tijm, et. al. have shown that several LMWPG, when added to premium diesel fuel at 10-11% (by wt.), reduce particulate emissions during combustion by up to 28% versus unmodified premium diesel. Certain embodiments of the invention disclosed herein provide a process for converting glycols (such as, for example, ethylene glycol and propylene glycol) into products suitable for use as fuel additives that comprises the steps of: (a) providing a biomass-derived feedstream comprising light glycols, where the glycols contain two, three or four carbon atoms, (b) contacting the feedstream with a first catalyst in a reactor, where the contacting results in an acidic condensation reaction that converts a least a portion of the feedstream to condensation products, and where said condensation products possess at least 4 carbon atoms and one ether functional group, (c) converting at least a portion of the remaining hydroxyl functional groups on the condensation products from step (b) to ether functional groups by combining the condensation products with a second catalyst to produce a liquid hydrocarbon mixture suitable for use as an additive to liquid hydrocarbon fuels, wherein the converting takes place in the presence of an olefin, monofunctional alcohol or mixtures thereof, and wherein the liquid hydrocarbon mixture has increased miscibility in liquid hydrocarbon fuels as a result of step c). Certain alternative embodiments of the invention disclosed herein provide a process for converting glycols (such as, for example, ethylene glycol and propylene glycol) into products suitable for use as fuel additives that comprises the steps of: (a) providing a biomass-derived feedstream comprising light glycols, where the glycols contain two, three or four carbon atoms, (b) contacting the feedstream with a first catalyst in a reactor, where the contacting results in an acidic condensation reaction that converts a least a portion of the feedstream to condensation products, and where said condensation products possess at least 4 carbon atoms and one ether functional group, (c) reducing at least a portion of the remaining hydroxyl groups on the condensation products by combining the condensation products with a second catalyst in the presence of hydrogen to produce water and a liquid hydrocarbon mixture that is suitable for use as an additive for a liquid hydrocarbon fuel. This liquid hydrocarbon mixture has increased miscibility in liquid hydrocarbon fuels as a result of this reduction step. In certain embodiments, the functions of the first and second catalyst are performed by the same catalyst. In certain embodiments, the process additionally comprises combining the liquid hydrocarbon mixture of step (c) with a liquid hydrocarbon fuel to produce an improved liquid hydrocarbon fuel, wherein the improved liquid hydrocarbon fuel has improved combustion properties that may include increased cetane number, decreased emissions of environmental pollutants during combustion, or both. The first catalyst may comprise at least two elements, one selected from Group 4 of the periodic table, and the other selected from Group 6 of the periodic table. Alternatively, the first catalyst may be a microporous molecular sieve selected from the group consisting of crystalline silicoaluminophosphates and aluminosilicates, that has been chemically treated to decrease catalytic activity outside the internal channels of the catalyst. Preferably, the pore diameter of the molecular sieve catalyst restricts the formation of circular products inside its pores. In certain embodiments, the second catalyst may be an acidic macroreticular ion-exchange resin. In other embodiments, the second catalyst may be a microporous molecular sieve selected from the group consisting of crystalline silicoaluminophosphates and aluminosilicates, that has been chemically treated to decrease catalytic activity outside the internal channels of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS FIG.1 illustrates an acidic condensation of the current disclosure also referred to as etherification. FIG.2 illustrates outlines how a non-preferred cyclic product (p-dioxane) can be formed from the condensation product of two ethylene glycol molecules. DETAILED DESCRIPTION Process conditions for conducting condensation reactions are relatively mild when compared to other industrial processes, such as conventional naphtha hydrodesulfurization, which normally requires temperatures in the range of 285° C. to 370° C. Low temperatures are advantageous since at higher temperature elimination becomes a competing reaction mechanism. Elimination, like condensation, involves the removal of a small molecule from a parent, but there is no coupling associated with the reaction. Elimination results in the production of an unsaturated product (e.g., ethanol to ethylene.) While these limits exist, yields for this process are typically sufficient to operate at the commercial level for chemical production. The acidic condensation of the current disclosure could also be referred to as etherification, and is illustrated in FIG. 1 . Depicted in the first line, the acid catalyst donates a proton to a hydroxyl group of a first glycol molecule. By definition, a glycol is a diol where the two hydroxyl groups are attached to different carbons. Thus, the R groups shown in FIG. 1 represent a hydrocarbon chain comprising a second hydroxyl moiety. Referring to the second line of FIG. 1 , a hydroxyl group from a second glycol molecule to reacts with the electrophilic carbon adjacent to the proton-accepting hydroxyl. Finally, the third line of FIG. 1 depicts removal of a water molecule (and proton) forming an ether bond between the two glycols. Acid-catalyzed condensation of primary alcohols in the homogeneously catalyzed case occurs via an S N 2 mechanism. In this type of mechanism, the transition state involves the attacking nucleophile driving off the leaving group in a concerted mechanism. This acid catalyzed condensation reaction is distinct from the base-catalyzed condensation reaction developed by Guerbet, which instead produces branched, saturated alcohols and not ethers. Examples of the Guerbet condensation reaction being utilized to form saturated branched hydrocarbons are shown in U.S. Pat. No. 7,049,476 and US2008/0302001. Typical biomass-derived molecules suitable for conversion to LMWPG by the processes described herein include any diol comprising two to four carbon atoms. Examples include ethylene glycol, propylene glycol, 1,3-propanediol, 1,2,-butanediol, 1,3,-butanediol, 2,3-butanediol, and 1,4-butanediol. As mentioned above, it is possible to convert glycols into di-, tri-, and some larger LMWPG using a solid acidic catalyst. Derivatives of these LMWPG fall into a category of materials termed oxygenated cetane improvers. Oxygenated cetane improvers are larger, predominantly linear compounds with oxygen substituted for carbon periodically along the backbone. The oxygen content of oxygenated cetane improvers varies depending on the feedstream used in their formation. However, a National Renewable Energy Laboratory report by Murphy, et al. shows that number of polyglycols have been calculated to possess a high cetane number. In addition, preliminary findings by Tijm, et. al. have shown that several LMWPG, when added to premium diesel fuel at 10-11% (by wt.), reduce particulate emissions during combustion by up to 28% versus unmodified premium diesel. The condensation reactions associated with the processes described herein are generally conducted at a temperature ranging from about 100° C. to about 300° C. More preferably, these reactions are conducted at a temperature ranging from about 120° to about 260° C. The condensation reactions are generally conducted at a pressure ranging from about 200 kPa to about 8000 kPa. Preferably, reactions are conducted at a pressure ranging from about 500 kPa to about 5000 kPa. Additionally, condensation reactions of the present disclosure are generally conducted with a feedstream flow rate ranging from about 0.1 h −1 liquid weight hourly space velocity (LWHSV) to about 20 h −1 LWHSV. Preferably, reactions are conducted with a feedstream flow rate ranging from about 0.5 h −1 LWHSV to about 15 h −1 LWHSV. The condensation catalyst utilized may be any catalyst capable of condensing light glycols to produce LMWPG. Preferably, the catalyst is an acidic catalyst suitable for such reactions, such as tungstated zirconias (for example, WO 3 /ZrO 2 ), metal loaded tungstated zirconias (for example, Pt—WO 3 /ZrO 2 ), heteropoly acids (for example, H 4 SiW 12 O 40 ), supported sulfonic acids (for example, acidic Amberlyst™ ion-exchange resins [Rohm and Haas]). Other catalysts useful for such condensation reactions may include acidic metal oxide catalysts, such as niobium pentoxide. Preferably, the catalyst is a microporous molecular sieve selected from crystalline silicoaluminophosphates and aluminosilicates with a three-dimensional pore structure that selectively favors the production of linear condensation products within the pores of the zeolite, while minimizing production of undesirable cyclic secondary products. Such undesirable products include p-dioxane. FIG. 2 outlines how this non-preferred cyclic product 121 can be formed from the condensation product 115 of two ethylene glycol molecules 101 . In certain embodiments, the condensation catalyst is a surface-passivated zeolite (such as, for example, H-Y, H-USY, H-mordenite, or H-ZSM-5) that selectively favors the production of linear LMWPG within the internal pores of the zeolite, while further minimizing production of undesirable cyclic secondary products on the zeolite surface. P-dioxane is a bulky, cyclic structure that is less likely to form within the confines of a zeolite channel system at low temperatures. Selectivity toward the formation of LMWPG may be enhanced by surface passivation of the zeolite to block activity outside of the channel system. Methods for surface passivation of zeolites are familiar to those with knowledge in the art, and one example of a zeolite passivation procedure is provided in Example II of the current disclosure. Creating selectivity towards the favored primary poly-glycol product is important for the economic viability of the process at industrial scale, since p-dioxane is unsuitable for blending into fuels, and is a stable product that is difficult to convert back to a form that is useful as a biofuel component. Following condensation of the light glycol feed to form a LMWPG, in certain embodiments the remaining hydroxyl groups are modified by an additional “capping” step to produce a poly-glycol derivative. This end-capping of the terminal hydroxyl groups may be accomplished by any catalyst capable of catalyzing an etherification reaction between the remaining terminal hydroxyl groups and an olefin. The end product would preferably have increased miscibility in liquid hydrocarbon fuels, and thus, be more suitable for use as a fuel additive. Such capping techniques are understood by individuals having knowledge in the art, and examples of such techniques are provided in the previously mentioned papers by Karinen, et. al., Frustieri, et. al. and Keplacova, et. al. In certain alternative embodiments, the remaining hydroxyl groups that are present on the LMWPG following condensation of the light glycol feed are instead “capped” by an additional acidic condensation reaction in the presence of a monofunctional alcohol (such as, for example, methanol, ethanol or propanol). This step may be performed with the catalyst of step b), for example, or any other catalyst capable of catalyzing an etherification reaction between the remaining terminal hydroxyl groups of the LMWPG and the monofunctional alcohol. The monofunctional alcohol has only one functional group capable of participating in a further round of etherification, thus effectively preventing further growth of the polymer. The end product would preferably have increased miscibility in liquid hydrocarbon fuels, and thus, be more suitable for use as a fuel additive. In still other embodiments, the remaining hydroxyl groups that are present on the LMWPG following condensation of the light glycol feed are instead “capped” by mild hydrodeoxygenation (HDO) of the remaining hydroxyl functional groups. It is important that the HDO step be mild so as to not completely remove all oxygen from the LMWPG, as a certain amount of oxygen in the final product is desirable. This HDO step may be catalyzed by any of a number of commercially available catalysts, including commercial hydrotreating catalysts comprising Co and Mo, or Ni and Mo. Procedures for conducting such HDO reactions are commonly known in the art. The end product would preferably have increased miscibility in liquid hydrocarbon fuels, and thus, be more suitable for use as a fuel additive. EXAMPLES The following examples are each intended to be illustrative of a specific embodiment of the present invention in order to teach one of ordinary skill in the art how to make and use the invention. They are not intended to limit the scope of the invention in any way. Example I Preparation of Catalysts: 40 wt % H 4 SiW 12 O 40 /SiO 2 was prepared by incipient wetness impregnation. H 4 SiW 12 O 40 (Sigma-Aldrich) was dissolved in ethanol and added dropwise to Davicat SI 1103 (320 m 2 /g, −40/+60 mesh.) Samples were sealed for 24 hours and then dried for 12 hours at 90° C. in flowing nitrogen. 1 wt % Pt—WO 3 /ZrO 2 was prepared by precipitation of Zr(OH) 4 followed by the loadings of tungsten and platinum via incipient wetness impregnation. Pt was loaded onto the catalyst using aqueous hexachloroplatinic acid. Catalysts were dried at 150° C. for 6 hours, and calcined at 300° C. overnight in flowing air. H-MOR (Si/Al=10), NH4-USY (Si/Al=2.6), and TPA-ZSM-5 (Si/Al=15) were obtained from Zeolyst International. Extrudates were crushed and sieved to −20/+40 mesh. Zeolites containing template or in the ammonium form were converted into the acidic form by calcining in a muffle furnace under flowing air prior to use. Excess air was flowed over the catalyst while the samples were heated using a gradual heat/soak temperature profile to a final temperature of 450° C. The final temperature was maintained overnight (>12 hours.) Example II Hypothetical Example: Passivation of a Zeolite Catalyst with Either Poly(phenylmethyl)siloxane or Tetraethylorthosilicate: Zeolite catalysts useful in certain embodiments of the invention may be chemically-modified to passivate (i.e., block active sites on) the external surface of the catalyst, thereby increasing selectivity for the production of LMWPG. One examples of how this can be achieved is outlined in U.S. Pat. No. 6,228,789, which pertains to a method for silylation of zeolite catalysts, and is incorporated herein by reference. A zeolite H-ZSM-5 was contacted to incipient wetness with a 50 wt % solution of poly(phenylmethyl)siloxane (PPMS) in cyclohexane, and the catalyst was not pre-calcined prior to contacting. After loading of the catalyst, it was dried and calcined at 538° C. for 6 hrs. Alternatively, the H-ZSM-5 catalyst was loaded with a 50 wt. % solution of tetraethylorthosilicate (TEOS) under conditions identical to those used for loading with PPMS. Example III Catalytic Conversion Test Conditions: Unless otherwise noted, catalysts were tested in a standard, ¾-inch diameter down-flow reactor. A bed of heated glass beads was utilized upstream from the catalyst to preheat the feed to reaction temperature prior to contacting the catalyst. Typically 6 mL of catalyst was diluted in an inert material (alundum) to a constant 13 mL bed volume for screening runs. The reactor was heated using a three-zone Thermcraft™ furnace with independent temperature control for each zone. Liquid feed was delivered to the system by an ISCO™ 1000D syringe pump, and system pressure was controlled by a Tescom™ backpressure regulator. Samples were taken at one hour intervals, and conversion and selectivity percentages (unless otherwise noted) were calculated by averaging data obtained from three different samples taken at different time points. Catalysts were dried in-situ at the desired operating temperature for a minimum period of 30 minutes in at least 100 sccm H 2 at 2758 kPa psig prior to each run. Pt containing catalysts were reduced for a minimum of 30 minutes at 300° C. and 2758 kPa in 100 sccm of H 2 . Except as noted, runs were performed as follows: Ethylene glycol was obtained from Sigma-Aldrich™ (97% purity) and diluted to 50 vol. % in water, and was fed to the reactor at a constant liquid feed rate of 30 mL/hr. Reactions were typically performed at 200° C., 5.0 h −1 LVHSV, and 2758 kPa. Hydrogen was flowed at 100 sccm during screening runs as some catalysts tested needed spillover hydrogen for activity. Liquid sample collection began 1 hour after starting the feed. Samples were acquired at 1 hour intervals for 5 hours and analyzed on an Agilent™ 7890A gas chromatograph equipped with an Agilent™ HP-5 capillary column, and a flame ionization detector (FID). Ambient temperature non-condensable products were analyzed on-stream using a HP-5 capillary column with FID detection. Example IV The tungstated zirconia catalyst Pt—WO 3 /ZrO 2 was prepared as detailed in Example 1, and found to convert 18.5% (w/v) of the feed during the experiment. However, selectivity for the formation of LMWPG was only 1.7% (w/v). Instead, this catalyst produced a relatively large quantity of ethanol from the ethylene glycol feedstock. While not wishing to be limited by theory, it is hypothesized that this ethanol was formed by the intramolecular dehydration of ethylene glycol to form acetaldehyde, followed by reduction of the acetaldehyde at the Pt sites of the catalyst to form ethanol. Alternatively, ethanol may have formed through direct hydrogenolysis at Pt sites. Example V A member of the heteropoly acid catalyst family (with the formula H 4 SiW 12 O 40 /SiO 2 ) was tested for its ability to convert the glycol feedstock to LMWPG. At a run temp of 250° C., utilizing undiluted ethylene glycol at a feed rate of 15 ml/hr, this catalyst converted 74.7% of the feedstock (average of samples taken at third and fourth hours), with a selectivity of 20.3% for the formation of LMWPG. However, this catalyst produced a large percentage of p-dioxane product, which is unsuitable for use as a biofuel, or a cetane-increasing fuel additive. p-dioxane is formed from the product of an intermolecular condensation between two ethylene glycols molecules. The primary product of this condensation, diethylene glycol, can undergo intramolecular condensation and circularize to form p-dioxane. This is not desirable, because p-dioxane is not suitable for use as a cetane-enhancing additive, and is a relatively stable product that is difficult to convert into back into a form that can be used as a fuel, or fuel additive. Example VI The zeolite catalysts USY, mordenite, and ZSM-5 were obtained and used with similar Si/Al ratios for comparison (the Si/Al ratios were 2.6, 10 and 15, respectively.) The relatively low Si/Al ratios were selected to maximize the acid site quantity for each catalyst. Each zeolite catalyst exhibited conversion of the ethylene glycol feed (See Table 1) to form LMWPG. TABLE 1 Conversion of ethylene glycol to LMWPG by several zeolite catalysts. Si/Al % Selectivity Catalyst Ratio % Conv. for LMWPG H-USY 2.6 0.6 58.2 H-MOR (mordenite) 10 4.7 6.2 H-ZSM-5 15 15.8 61.5 Reaction products in addition to LMWPG were observed, including acetaldehyde and p-dioxane. The acetaldehyde was hypothesized to have formed by the intramolecular dehydration of ethylene glycol, while p-dioxane was thought to have formed by the mechanism outlined previously. Interestingly, the USY and ZSM-5 zeolites exhibited higher selectivity for the production of LMWPG than with the other catalysts tested previously. Example VII The ZSM-5 zeolite catalyst was selected for further testing to optimize reaction conditions for converting the ethylene glycol feed stock to LMWPG. Conditions of pressure, temperature and flow rate were altered, and the effect on percent conversion and selectivity for the formation of LMWPG is shown in Table 2: TABLE 2 Conversion of ethylene glycol to LMWPG at various reaction conditions: % % Temp. Pressure LWHSV Run Conversion Selectivity (° C.) (KPa) (hr −1 ) 1 1.20 71.7 126.5 689 1.5 2 0.14 53.6 126.5 689 15.0 3 0.45 93.2 124.5 2758 1.5 4 0.55 92.8 128 2758 1.5 5 0.21 100 126.5 2758 15.0 6 0.96 87.4 134.5 689 15.0 7 0.11 71.5 149 1724 8.25 8 1.60 85.4 154.5 1724 8.25 9 40.60 62.4 174 689 1.5 10 3.60 42.4 175.5 689 15.0 11 48.90 59.7 177.5 2758 1.5 12 1.80 84.5 174.5 2758 15.0 13 53.30 56.2 183.5 689 1.5 14 5.50 81.0 182 2758 15.0 DEFINITIONS As used herein, the term “liquid weight hourly space velocity” or “LWHSV” refers to the liquid weight hourly space velocity. As used herein, the term “cetane” or “cetane number” refers to the cetane number of a fuel as measured by the ASTM (American Society for Testing and Materials) D613 or D6890 standard. As used herein, the term “transportation fuel” refers to any liquid hydrocarbon mixture used as a fuel for powering engines, including gasoline, diesel and jet fuels. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as examples of embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims. REFERENCES All of the references cited herein are expressly incorporated by reference. Incorporated references are listed again here for convenience: 1. US2010/0094062 (Rabello; Ferreiral; Menenzes); “Cetane Number Increasing Process and Additive for Diesel Fuel.” 2. US2008/0300435 (Cortright; Blommel); “Synthesis of Liquid Fuels and Chemicals From Oxygenated Hydrocarbons.” 3. US2008/0302001 (Koivusalmi; Piiola; Aalto) “Process for Producing Branched Hydrocarbons.” 4. U.S. Pat. No. 7,049,476 (O'Lenick, Jr.) “Guerbet Polymers” (2006). 5. U.S. Pat. No. 6,228,789 (Wu; Drake) “Silylated Water Vapor Treated Zinc or Gallium Promoted Zeolite and Use Thereof for the Conversion of Non-aromatic Hydrocarbons to Olefins and Aromatic Hydrocarbons” (2001). 6. Klepacova, K., et al., “Etherification of Glycerol and Ethylene Glycol by Isobutylene.” Applied Catalysis A: General 328: 1-13 (2007). 7. Klepacova, K., et al., “tert-Butylation of Glycerol Catalyzed by Ion-Exchange Resins.” Applied Catalysis A: General 294: 141-147 (2005). 8. Karinen, R. et al., “New Biocomponents from Glycerol” Applied Catalysis A: General 306: 128-133 (2006). 9. Frusteri, F., et al., “Catalytic Etherification Of Glycerol By tert-Butyl Alcohol To Produce Oxygenated Additives For Diesel Fuel.” Applied Catalysis A: General 367: 77-83 (2009). 10. Tijm, P. et al., “Effect of Oxygenated Cetane Improver on Diesel Engine Combustion & Emissions” http://www.energy.psu.edu/tecetane.html 11. Murphy, M. et al., “Compendium of Experimental Cetane Number Data” NREL/SR-540-36805 (2004). http://www.nrel.gov/vehiclesandfuels/pdfs/sr368051.pdf

The present disclosure relates to methods for converting light glycol streams of biological origin into products suitable for use as oxygenated fuel additives. These methods involve the acidic condensation of light glycols to form larger products, termed low molecular weight poly-glycols. The remaining hydroxyl functional groups of the poly-glycol products are then modified to decrease the overall polarity of the products, and improve their suitability for use as an oxygenated fuel additive.

[0001] The present disclosure relates to the subject matter contained in Japanese Patent Application No. 2002-143564 filed on May 17, 2002, which is incorporated herein by reference in its entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates to a navigation apparatus and, more particularly, a navigation apparatus to which a communication device can be connected. [0004] 2. Description of the Related Art [0005] In the navigation apparatus according to the related art, there are a system to which a communication device such as a mobile phone can be connected to execute communication (including speech) with the outside, and a system which has a hand-free communication function to execute speech during running safely and comfortably. [0006] In the navigation apparatus to which such a communication device is connected, when the navigation apparatus detects an incoming call or an outgoing call of the mobile phone and then enters into a call mode, the speech of the other person in communication is output from a loudspeaker connected to the navigation apparatus and also the speech picked up by a microphone connected to the navigation apparatus is transmitted via the communication device, so that user can speak with a person who issues/receives the call. [0007] In such navigation apparatus in the related art, the speech while driving can be executed safely and comfortably by the hand-free communication function, etc. However, such systems do not deal with a case where user wishes to take notes of the content of the speech. Therefore, in order to take notes during speaking, a writing paper, a writing tool, etc. must be taken out. But it is difficult for a driver to prepare them while driving, and such motion of the driver leads to careless forward looking and is undesirable for safety. [0008] Also, it is troublesome even in the stopping state to take notes by taking out the writing paper, the writing tool, etc. every time while speaking. In addition, it is impossible to take notes at once unless the writing tool, etc. are prepared previously. Thus, there is such a problem that such navigation apparatus is inconvenient. [0009] Also, in some cases, a driver talks while looking at map information displayed on a screen according to situations. Thus, in such states, the driver would like to take notes of information such as a location of a destination, surrounding buildings, where to make contact, etc., which are heard from the other person in communication. In this case, there is such a problem that the driver cannot easily take notes of the information while looking at the map. [0010] In addition, in the navigation apparatus according to the related art, such a system has not been provided that speech contents, memo contents, etc. can be automatically registered in a database such as an address book and a phone book. Thus, user must input necessary registration contents separately once again. Hence, there is such a problem that an operation becomes cumbersome and troublesome. SUMMARY OF THE INVENTION [0011] The invention has been made in view of the above subjects. It is an object of the invention to provide a navigation apparatus, which is serviceable and convenient of use for the user, and is capable of taking notes easily to display the notes on a display screen while displaying a navigation screen at a time of talking over the phone and also capable of putting memo information to practical use. [0012] In order to achieve the above object, according to a first aspect of the invention, a communication device for communicating with an external is connectable to a navigation apparatus. The navigation apparatus includes a display portion, an input portion, an outgoing/incoming call determination portion, and a display control portion. The input portion inputs memo information. The outgoing/incoming call determination portion determines whether the communication portion conducts an outgoing call and determining whether the communication portion receives an incoming call. The display control portion controls the display portion. When the outgoing/incoming call determination portion concludes that the communication portion conducts the outgoing call or that the communication portion receives the incoming call, the display control portion splits the display portion into a memo screen on which content of the memo information is displayed and a navigation screen. [0013] In the first aspect, when the incoming call or the outgoing call of the communication portion is detected, the display portion is split/displayed into the memo screen and the navigation screen. Therefore, for example, while displaying the navigation screen on which the map for the route guidance is displayed, memo information input via the input portion can be displayed on the memo screen. As a result, in order to take the notes, the user is not required to take out the writing paper, the writing tool, etc. every time and to prepare them previously. Thus, the user can take notes easily and the convenience in use for the user can be improved. [0014] According to a second aspect of the invention, the navigation apparatus of the first aspect further includes a memo input processing portion for conducting a predetermined process based on a predetermined input signal from the input portion. [0015] In the second aspect, the predetermined operating process is executed based on the predetermined input signal from the input portion. Therefore, the predetermined operating process is executed simply can be executed simply. Thus, the convenience in use for the user can be further improved. [0016] According to a third aspect of the invention, in the second aspect, the predetermined process includes a process for starting to take notes on the memo screen and a process for terminating to take notes on the memo screen. [0017] According to a fourth aspect of the invention, in any one of the first and second aspects, the input portion includes a touch panel for drawing the memo information on the memo screen in accordance with a touch operation. The navigation apparatus further includes a character recognition portion, a memo information storage portion, and a first storage control portion. The character recognition portion recognizes the memo information drawn on the memo screen as character data. The first storage control portion stores the character data recognized by the character recognition portion into the memo information storage portion. [0018] In the fourth aspect, the user can take notes simply on the memo screen via the touch panel. Also, the drawing data are recognized as the character data. Then, the recognized character data are stored as the memo information in the memo information storing portion. Therefore, a memory capacity can be reduced rather than a case where the drawing data are to be stored. Also, the character data that are subjected to the character recognition can be used positively in other applications. As a result, the availability of the drawing data can be enhanced. [0019] According to a fifth aspect of the invention, in the fourth aspect, the display control portion display the character data recognized by the character recognition portion on the memo screen. [0020] In the fifth aspect, the character data that are recognized by the character recognition portion are displayed on the memo screen. Therefore, the user can check whether or not the character recognition has been executed precisely. [0021] According to a sixth aspect of the invention, in any one of the first to fifth aspects, the input portion includes a voice acquiring portion for acquiring voice as voice data. The navigation apparatus further includes a voice recognition portion, a memo information storage portion, and a second storage control portion. The voice recognition portion recognizes as character data the voice data acquired by the voice acquiring portion and voice data received by the communication portion. The second storage control portion stores the character data recognized by the voice recognition portion into the memo information storage section. [0022] In the sixth aspect, the voice data that are received by the voice acquiring portion and the voice data that are received by the communication portion are recognized as the character data, and then are stored in the memo information storage portion. Therefore, the memory capacity can be reduced rather than a case where the voice data are to be stored. Also, the character data that are subjected to the voice recognition can be used positively in other applications. As a result, the availability of the voice data can be enhanced. [0023] According to a seventh aspect of the invention, in the sixth aspect, the display control portion display the character data recognized by the voice recognition portion on the memo screen. [0024] In the seventh aspect, the character data that are recognized by the voice recognition portion are displayed on the memo screen. Therefore, the user can check whether or not the voice recognition has been executed precisely. [0025] According to an eighth aspect of the invention, the navigation apparatus of any one of the sixth and seventh aspects, further includes a memo input processing portion and an operation keyword registration portion. The memo input processing portion conducts a predetermined process based on a predetermined input signal from the input portion. The operation keyword registration portion registers an operation keyword. When the voice data acquired by the voice acquiring portion coincides with the operation keyword, the memo input processing portion conducts the predetermined process. [0026] In the eighth aspect, the user can register the operation keyword. Also, when the voice that corresponds to the operation keyword is received by the voice acquiring portion, the predetermined operating process is carried out. Therefore, the operation of the user to take notes can be facilitated, and thus the convenience in use for the user can be improved. [0027] According to a ninth aspect of the invention, in the eighth aspect, the operation keyword registration portion registers the operation keyword for each other person in communication individually. [0028] In the ninth aspect, since the operation keyword is registered individually in response to the other person in communication, the operation keyword can be changed in answer to the other person in communication. Therefore, this navigation apparatus can deal with various applications of the user, and thus the convenience in use for the user can be improved much more. [0029] According to a tenth aspect of the invention, the navigation apparatus of any one of the fourth to ninth aspects, further includes a character-extraction keyword registration portion for registering a character extraction keyword utilized for extracting a predetermined character data from the character data recognized by the character recognition portion. [0030] In the tenth aspect, the user can register the character extraction keyword. Therefore, the user can extract the predetermined character data, which the user wishes to extract, from the character data. Also, extraction of the predetermined character data can be executed to meet the needs of the user. [0031] According to an eleventh aspect of the invention, in the tenth aspect, the character-extraction keyword registration portion registers the character extraction keyword for each other person in communication individually. [0032] In the eleventh aspect, since the character extraction keyword is registered individually in response to the other person in communication, the character data to be extracted can be changed in answer to the other person in communication. Therefore, this navigation apparatus can deal with various applications of the user, and thus the convenience in use for the user can be further improved. [0033] According to a twelfth aspect of the invention, the navigation apparatus of the tenth or eleventh aspect, further includes a character data extraction portion and a character data registration portion. The character data extraction portion extracts a predetermined character data from the character data based on the character extraction keyword. The character data registration portion registers the extracted character data by the character data extraction portion in a predetermined data base. [0034] In the twelfth aspect, the predetermined character data are extracted from the character data based on the character extraction keyword. Then, the predetermined character data that have been extracted are registered in the predetermined database. Therefore, the labor t hat is required of the user to input the registered items separately to register in the database can be omitted, and thus this navigation apparatus becomes serviceable and convenient of use for the user. [0035] According to a thirteenth aspect of the invention, in the twelfth aspect, the character data registration portion includes an update information determination portion and an update information registration portion. The update information determination portion determines whether update information relating to the predetermined data base is contained in the predetermined character data extracted by the character data extraction portion. The update information registration portion registers the update information in the predetermined data base when the update information determination portion concludes that the update information is contained. [0036] In the thirteenth aspect, only when it is concluded that the update information are contained in the predetermined character data, the update information can be registered in the predetermined database. Therefore, the update of the predetermined database can be executed appropriately. [0037] According to a fourteenth aspect, the navigation apparatus of any one of the twelfth and thirteenth aspects, further includes a character data correction portion for correcting the character data registered in the predetermined data base by the character data registration portion, desirably. [0038] In the thirteenth aspect, even if wrong data are registered in the predetermined database, the user can correct such wrong data arbitrarily and also necessary data can be added/corrected. Therefore, the precision of the information that are registered in the predetermined database can be enhanced. BRIEF DESCRIPTION OF THE DRAWINGS [0039] [0039]FIG. 1 is a block diagram showing schematically a pertinent portion of a navigation apparatus according to an embodiment (1) of the invention. [0040] [0040]FIG. 2 is a view showing an example displayed on a display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0041] [0041]FIG. 3 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0042] [0042]FIG. 4 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0043] [0043]FIG. 5 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0044] [0044]FIG. 6 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0045] [0045]FIG. 7 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0046] [0046]FIG. 8 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0047] [0047]FIG. 9 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0048] [0048]FIG. 10 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0049] [0049]FIG. 11 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0050] [0050]FIG. 12 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (1). [0051] [0051]FIG. 13 is a flowchart explaining processing operations of a memo function executed by a navigation control portion in the navigation apparatus according to the embodiment (1). [0052] [0052]FIG. 14 is a flowchart explaining processing operations in a database correction executed by the navigation control portion in the navigation apparatus according to the embodiment (1). [0053] [0053]FIG. 15 a block diagram showing schematically a pertinent portion of a navigation apparatus according to an embodiment (2) of the invention. [0054] [0054]FIG. 16 is a view showing an example displayed on a display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0055] [0055]FIG. 17 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0056] [0056]FIG. 18 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0057] [0057]FIG. 19 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0058] [0058]FIG. 20 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0059] [0059]FIG. 21 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0060] [0060]FIG. 22 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0061] [0061]FIG. 23 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0062] [0062]FIG. 24 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0063] [0063]FIG. 25 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0064] [0064]FIG. 26 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0065] [0065]FIG. 27 is a view showing an example displayed on the display screen to explain a utilization mode of the navigation apparatus according to the embodiment (2). [0066] [0066]FIG. 28 is a flowchart explaining processing operations of a memo function executed by a navigation control portion in the navigation apparatus according to the embodiment (2). [0067] [0067]FIG. 29 is a flowchart explaining processing operations in a voice operation keyword registration executed by the navigation control portion in the navigation apparatus according to the embodiment (2). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0068] Embodiments of a navigation apparatus according to the invention will be explained with reference to the drawings hereinafter. FIG. 1 is a block diagram showing schematically a pertinent portion of a navigation apparatus according to an embodiment (1) of the invention. [0069] A speed sensor 11 and a gyro sensor 12 are connected to a navigation control portion 10 (hereinafter referred to as “navi control portion”). The speed sensor 11 calculates a vehicle speed to acquire the covered distance. The gyro sensor 12 acquires a running direction. The navi control portion 10 determines a location of own vehicle based on the covered distance and the running direction (Self-Contained Navigation). [0070] Also, a GPS receiver 14 for receiving the GPS signal from a satellite via an antenna 13 is connected to the navi control portion 10 . The navi control portion 10 also determines the location of own vehicle based on the GPS signal (GPS Navigation). [0071] Also, a DVD drive 16 that can pick out electronic map data, etc. from a DVD-ROM 15 , in which map information including the electronic map data is stored, is connected to the navi control portion 10 . The navi control portion 10 executes a process of matching the determined location of own vehicle with the electronic map data, i.e., a so-called map matching process at a predetermined time interval, and executes a process of displaying a map, on which the location of own vehicle is indicated precisely, on a display screen 18 a. [0072] Also, a display device 18 is connected to the navi control portion 10 via a drawing/display control portion 17 . A touch panel 18 b is provided on a display screen 18 a of the display device 18 . The touch panel 18 b makes possible an input operation via operation buttons displayed on the display screen 18 a, etc. and an input operation of characters, etc. into a predetermined drawing area of the display screen 18 a by the handwriting. [0073] Also, a communication portion 19 having a radio device such as a mobile phone, a voice output portion 20 having an amplifier and a loudspeaker, a voice input portion 21 having a microphone that can pick up voice from the outside, and a character recognition portion 22 for recognizing drawing data such as characters, which are input by the handwriting via the touch panel 18 b, as character data are connected to the navi control portion 10 . [0074] When the navi control portion 10 detects an incoming call or an outgoing call of the communication portion 19 to enter in a call mode, the navi control portion 10 causes the display device 18 to execute a process of splitting the display screen 18 a into a navigation screen and a memo screen, into which the characters and the like can be input by the handwriting via the touch panel 18 b. [0075] The drawing/display control portion 17 executes a drawing/displaying process based on a drawing/display instruction issued from the navi control portion 10 . For example, the drawing/display control portion 17 executes a process of switching the display screen 18 a into the split display screen consisting of the navigation screen and the memo screen, a process of drawing/displaying characters and the like, which are input by the handwriting via the touch panel 18 b, on the memo screen, and a process of displaying a map and the like on the navigation screen. [0076] The character recognition portion 22 executes a process of recognizing drawing data such as characters and the like, which are input into the memo screen by the handwriting via the touch panel 18 b, as character data based on the instruction issued from the navi control portion 10 . The drawing/display control portion 17 executes a process of displaying the character data, which are recognized by the character recognition portion 22 , on the display screen 18 a based on the instruction issued from the navi control portion 10 . [0077] Also, the navi control portion 10 executes a process of converting the voice data of the other person, which is received via the communication portion 19 , in communication into voice and then outputting such voice from the voice output portion 20 , and a predetermined voice process of outputting the voice data, which are input from the voice input portion 21 , to the communication portion 19 to communicate with the other person. [0078] Also, the navi control portion 10 executes a process of storing memo information containing the character data, which are recognized by the character recognition portion 22 , and communication history information such as communication date, the other person of communication and the like into a memory 23 . Also, the navi control portion 10 decides whether or not the update information the contents of which correspond to the set item of the database stored in the memory are contained, and then executes a process of updating the contents of the database if the update information are contained. [0079] As the database stored in the memory 23 , there are listed, for example, the phone book database that are downloaded via the communication portion 19 and stored in the memory 23 , the destination database that is linked with the information of the phone book and the address book, which are taken out from the DVD-ROM 15 , to set the destination, etc. [0080] Also, as the set items of the database, in the case of the phone book, for example, name, phone number, address, mail address, date of birth, interest, inclination, etc. can be provided. [0081] [0081]FIG. 2 to FIG. 10 are views showing examples displayed on the display screen 18 a to explain utilization modes of the navigation apparatus according to the embodiment (1). [0082] [0082]FIG. 2 shows a display example that the incoming call of the communication portion 19 is detected while the navigation screen for guiding to the destination is being displayed to execute a route guidance to the destination. Call incoming information 31 indicating that the incoming call is detected is displayed on the display screen 18 a. In this case, if the incoming call is issued from the person who is registered previously in the phone book database stored in the memory 23 , the name, the phone number, etc. of the person who issued the incoming call can be also displayed. [0083] Then, when the system enters into a call mode by a predetermined call-receiving operation, the display screen 18 a is shifted to the split display screen shown in FIG. 3. In the split display screen shown in FIG. 3, a memo screen 32 , on which the characters, etc. input by the handwriting via the touch panel 18 b are drawn and displayed, and a navigation screen 33 , on which the map information, etc. used to execute the route guidance are displayed continuously, are displayed in a split mode on the display screen 18 a. In this display mode, the user can take notes easily by inputting contents, which are to be noted on the memo screen 32 , by the handwriting. [0084] Then, when a “record” button being displayed on the memo screen 32 is pushed (touch-input) via the touch panel 18 b, a process of recognizing the drawing data such as the handwritten characters, etc. as the character data is executed. Then, the screen is shifted to a “character-recognition check” screen shown in FIG. 4. [0085] In the character-recognition check screen shown in FIG. 4, the recognized characters are displayed on the memo screen 32 . When results of the character recognition contain a portion to be corrected and also a “correct” button is touch-input, the screen is shifted to a correction screen (not shown). Then, the correction can be carried out by predetermined correcting procedures, for example, by the correction input of the characters that are input by the handwriting via the touch panel 18 b, the correction input of the characters based on the Japanese syllabary display, the correction input of the characters based on the display in alphabetical order, etc. [0086] Also, when results of the character recognition contain no correction and also an “OK” button is touch-input, the recognized character data are stored in the memory 23 as memo information, and also a process of searching whether or not the update information, which correspond to the set item of the database stored in the memory, are contained in the memo information is executed. After the searching process, if it is concluded that the update information is contained, the screen is shifted to a “database update indication” screen shown in FIG. 5. [0087] In the database update indication screen shown in FIG. 5, the updating instruction of the database is displayed on the memo screen 32 . When an “update” button is touch-input, the screen is shifted to an “update information check” screen shown in FIG. 6. [0088] In the “update information check” screen shown in FIG. 6, the update person, the update item, and the like are displayed on the memo screen 32 . When an “OK” button is touch-input, the contents of the database are updated automatically. Also, when the error is found in the update person, the update item, and the like and also a “change” button is touch-input, the screen is shifted to a “change” screen (not shown) and then the update person, the update item, and the like can be changed via this change screen. After the change, the screen goes back to the update information check screen shown in FIG. 6 again. Then, when the “OK” button is touch-input, the contents of the database are updated automatically according to the setting after the change. Then, the display screen 18 a is switched from the split display screen consisting of the memo screen 32 and the navigation screen 33 to one display screen consisting of the navigation screen after the updating process of the database. [0089] Also, the memo information stored in the memory 23 can be read later. When a “memo information” button provided in the “menu” screen shown in FIG. 7 is touch-input, the screen is shifted to a “memo information list display” screen shown in FIG. 8. [0090] In the “memo information list display” screen shown in FIG. 8, communication date, communicated person (if the other person in communication is identified), and the memo that is subjected to the character recognition are displayed. The memo information can be displayed in order of the data by operating a scroll key 34 . Also, function switches such as “cancel”, etc. are provided at the bottom of the screen. For example, the unnecessary memo can be erased easily by designating the memo information, which are to be cancelled, by the touch operation and then touch-inputting the “cancel” button. [0091] Also, the information of the database stored in the memory 23 can be corrected later. If a “database correction” button provided on the “menu” screen shown in FIG. 7 is touch-input, the screen is shifted to a “correcting-database selection” screen shown in FIG. 9. [0092] In the “correcting-database selection” screen shown in FIG. 9, a list of the databases stored in the memory 23 is displayed and the database containing information to be corrected can be selected. Then, a button of the database containing the information to be corrected (in this case, “phone book database”) is touch-input, the screen is shifted to a “phone book database correction” screen shown in FIG. 10. [0093] In the “phone book database correction” screen shown in FIG. 10, a screen on which the name of the person containing the information to be corrected is selected is displayed. When the name of the person containing the information to be corrected is displayed and then a name button that is being displayed (in this case, “Yamashita . . .” button) is touch-input, the screen is shifted to a “correcting item selection” screen shown in FIG. 11. [0094] In the “correcting item selection” screen shown in FIG. 11, a list of the set items of the database is displayed, and the set item containing the information to be corrected can be selected. Then, a button of the set item containing the information to be corrected (in this case, “phone number” button) is touch-input, the screen is shifted to a “item correction” screen shown in FIG. 12. [0095] In the “item correction” screen shown in FIG. 12, the registered information can be corrected. In this case, the phone number can be corrected into the correct phone number by touch-inputting the numeral button. If an “end” button is touch-input after the correction, the phone number is corrected to the corrected content. Then, the screen returns to the menu screen shown in FIG. 7. [0096] Next, processing operations of the memo function executed by the navi control portion 10 in the navigation apparatus according to the embodiment (1) will be explained with reference to a flowchart shown in FIG. 13 hereunder. [0097] First, in step S 1 , it is decided whether or not the “outgoing call” or the “incoming call” of the communication portion 19 is detected. If it is concluded that the “outgoing call” or the “incoming call” of the communication portion 19 is detected, the process goes to step S 2 . In contrast, if it is concluded that the “outgoing call” or the “incoming call” of the communication portion 19 is not detected, the process is ended. [0098] In step S 2 , the display indicating that the outgoing call or incoming call is detected as shown in FIG. 2 is executed. Then, the process goes to step S 3 . [0099] In step S 3 , it is decided whether or not the navigation apparatus has entered into the call mode, i.e., the system is in a call mode. If it is concluded that the system has entered into the call mode, the process goes to step S 4 . In contrast, in step S 3 , when it is concluded that the system has not entered into the call mode, the process is ended. [0100] In step S 4 , the process of splitting the display screen 18 a into the memo screen 32 and the navigation screen 33 shown in FIG. 3 to display it is executed. Then, the process goes to step S 5 . In step S 5 , the memo drawing/displaying process, i.e., the process of drawing/displaying the memo contents such as the characters, numerals, etc., which are input into the memo screen 32 by the handwriting via the touch panel 18 b, on the memo screen 32 is executed. Then, the process goes to step S 6 . [0101] In step S 6 , it is decided whether or not the call mode is ended, i.e., the talking state is disconnected. If it is concluded that the call mode is not ended, the process goes back to step S 5 . In contrast, if it is concluded that the call mode is ended, the process goes to step S 7 . [0102] In step S 7 , it is decided which one of a “record” button, which is used to store the memo being drawn on the memo screen 32 into the memory 23 as the memo information, and a “cancel” button, which is used to cancel the memo being drawn on the memo screen 32 , is touch-input. If it is concluded that the “record” button is input, the process goes to step S 8 . In contrast, if it is concluded that the “cancel” button is input, the drawing data are canceled. Then, the process goes to step S 19 . [0103] In step S 8 , the character recognizing process, i.e., the process of causing the character recognition portion 22 to recognize the memo contents, which are drawn on the memo screen 32 , as the character data is executed. Then, the process goes to step S 9 . In step S 9 , as shown in FIG. 4, the process of displaying the characters recognized by the character recognition portion 22 on the memo screen 32 . Then, the process goes to step S 10 . [0104] In step S 10 , it is decided whether or not the “OK” button displayed on the memo screen 32 is touch-input. If it is concluded that the “OK” button is touch-input, the process goes to step S 11 . [0105] In contrast, in step S 10 , if it is concluded that the “OK” button is not touch-input, the process goes to step S 20 . In step S 20 , it is decided whether or not a “correction” button is touch-input. If it is concluded that the “correction” button is touch-input, the process goes to step S 21 . In step S 21 , the recognized character correcting process, i.e., the process of correcting the recognized characters is executed. Aster the correcting process, the process goes back to step S 10 . In contrast, in step S 20 , if it is concluded that the “correction” button is not touch-input, the process goes back to step S 10 . [0106] In step S 11 , the process of storing the communication date, the other person in communication, and the recognized characters into the memory 23 as the memo information is executed. Then, the process goes to step S 12 . [0107] In step S 12 , the process of searching whether or not the update information, which correspond to the set item of the database stored in the memory 23 , are contained in the memo information is executed. Then, the process goes to step S 13 . [0108] In step S 13 , it is decided whether or not the update information are contained in the memo information. If it is concluded that the update information are contained, the process goes to step S 14 . In contrast, in step S 13 , if it is concluded that the update information are not contained, the process goes to step S 19 . [0109] In step S 14 , the process of displaying the update indication screen of the database update information shown in FIG. 5 on the memo screen 32 is executed. Then, the process goes to step S 15 . In step S 15 , it is decided which one of an “update” button, which is used to update the information to the recognized characters, and a “not update” button, which is used not to update the information, is touch-input. If it is concluded that the “update” button is touch-input, the process goes to step S 16 . In contrast, in step S 15 , it is concluded that the “not update” button is touch-input, the process goes to step S 19 . [0110] In step S 16 , the process of displaying the “update information check” screen shown in FIG. 6 on the memo screen 32 is executed. Then, the process goes to step S 17 . In step S 17 , it is decided whether or not an “OK” button for updating the database by using the contents displayed on the memo screen 32 is touch-input. If it is concluded that the “OK” button is touch-input, the process goes to step S 18 . [0111] In contrast, in step S 17 , if it is concluded that the “OK” button is not touch-input, the process goes to step S 22 . In step S 22 , it is decided whether or not a “change” button that is used to change the displayed contents is touch-input. If it is concluded that the “change” button is touch-input, the process goes to step S 23 . In step S 23 , the process of changing the update person, the update item, etc. in compliance with the screen display is executed. After the change is ended, the process goes back to step S 17 . In contrast, in step S 22 , it is concluded that the “change” button is not touch-input, the process goes back to step S 17 . [0112] In step S 18 , the database updating process of updating the contents of the update items of the update person, which are displayed on the memo screen 32 , into the recognized character data is executed. Then, the process goes to step S 19 . In step S 19 , the process of switching the display screen 18 a, which is split/displayed into the memo screen 32 and the navigation screen 33 , to one display screen of the navigation screen is executed. Then, the process is ended. [0113] Next, processing operations in the database correction executed by the navi control portion 10 in the navigation apparatus according to the embodiment (1) will be explained with reference to a flowchart shown in FIG. 14 hereunder. [0114] First, in step S 31 , in the “menu” screen shown in FIG. 7, it is decided whether or not a “database correction” button is touch-input. If it is concluded that the “database correction” button is not touch-input, the process is ended. In contrast, if it is concluded that the “database correction” button is touch-input, the process goes to step S 32 . [0115] In step S 32 , the process of displaying the correcting-database selection screen shown in FIG. 9 is executed. Then, the process goes to step S 33 . In step S 33 , it is decided whether or not the correcting database is touch-input. If it is concluded that the correcting database is not touch-input, the process is ended. In contrast, if it is concluded that the correcting database is touch-input, the process goes to step S 34 . [0116] In step S 34 , the process of displaying the correction screen of the database shown in FIG. 10 (in this case, first a name selection screen) is executed. Then, the process goes to step S 35 . In step S 35 , it is decided whether or not the name of the person to be corrected is touch-input. If it is concluded that the name is not touch-input, the process is ended. In contrast, if it is concluded that the name is touch-input, the process goes to step S 36 . [0117] In step S 36 , the process of displaying the correcting item selection screen shown in FIG. 11 is executed. Then, the process goes to step S 37 . In step S 37 , it is decided whether or not the item to be corrected is touch-input. If it is concluded that the item to be corrected is not touch-input, the process is ended. In contrast, if it is concluded that the item to be corrected is touch-input, the process goes to step S 38 . [0118] In step S 38 , the process of displaying the item correction screen shown in FIG. 12 is executed. Then, the process goes to step S 39 . In step S 39 , the process of displaying the corrected content being input in the item correction screen is executed. Then, the process goes to step S 40 . [0119] In step S 40 , it is decided whether or not an “end” button is touch-input. If it is concluded that the “end” button is not touch-input, the process is ended. In contrast, if it is concluded that the “end” button is touch-input, the process goes to step S 41 . In step S 41 , the process of updating the content of the selected set item into the corrected content is executed. Then, the process is ended. [0120] According to the navigation apparatus according to the above embodiment (1), when the incoming call or the outgoing call of the communication portion 19 is detected, the display screen 18 a is split/displayed into the memo screen 32 and the navigation screen 33 and then the memo contents can be drawn/displayed by the handwriting via the touch panel 18 b on the memo screen 32 . Hence, the user is not required to take out the writing paper, the writing tool, etc. every time and to prepare them previously, in order to take the notes. Therefore, the user can take notes easily and the convenience in use for the user can be improved. [0121] Also, the drawing data are recognized as the character data by the voice recognition portion 22 , and then the recognized character data are displayed on the memo screen 32 . Therefore, the user can check whether or not the character recognition has been executed precisely. Also, the recognized character data are stored as the memo information in the memory 23 . Therefore, a memory capacity can be reduced rather than a case where the drawing data are stored. Also, the character data that are subjected to the character recognition can be used positively in the application such as the update of the database stored in the memory 23 . As a result, the availability of the drawing data can be enhanced. [0122] Also, the searching process of extracting the character data, which correspond to the contents of the set items, from the character data, which are subjected to the character recognition, based on the character extraction keywords that are set beforehand to correspond to the set items of the database. Thus, if it is concluded that the update information are contained in the character data, such update information can be registered in the predetermined database. Therefore, a labor that is required of the user to input registered items separately and register them in the database can be omitted, and the navigation apparatus becomes serviceable and convenient of use for the user. [0123] Also, even if the wrong data are registered in the database, such wrong data can be corrected in compliance with the database correction screen and also necessary contents can be added later. Therefore, a precision of the information that are registered in the database stored in the memory 23 can be enhanced. [0124] Next, a navigation apparatus according to an embodiment (2) of the invention will be explained hereunder. FIG. 15 is a block diagram showing schematically a pertinent portion of the navigation apparatus according to the embodiment (2). In this case, the same symbols are affixed to the similar constituent parts to those in the navigation apparatus according to the embodiment (1) shown in FIG. 1, and thus their explanation will be omitted herein. [0125] A difference between the navigation apparatus according to the embodiment (2) and the navigation apparatus according to the embodiment (1) is that a voice recognition portion 24 is connected to a navi control portion 10 a in place of the character recognition portion 22 . The character data that are voice-recognized by the voice recognition portion 24 are displayed as a memo (conversation memo) on the memo screen that is displayed in the split display mode after the system entered into the call mode. Also, different symbols are affixed to the navi control portion 10 a, a drawing/display control portion 17 a, and a memory 23 a, which have different functions from those in the embodiment (1). [0126] The voice recognition portion 24 executes a process of recognizing the voice data, which are received by the voice input portion 21 , and the voice data, which are received by the communication portion 19 , as the character data based on the instruction issued from the navigation control portion 10 a. [0127] In procedures in the voice recognizing process executed by the voice recognition portion 24 , first a voice interval indicating an interval in which an target voice to be recognized is present is detected. Then, the voice analysis for analyzing features of the target voice to convert the voice into feature parameters is executed. Then, the phoneme recognition for separating the target voice into the phonemes or the syllables as the recognition unit of the voice to collate them with the phoneme patterns is executed. Then, the word recognition for combining the words based on the recognized results obtained at a phoneme or syllable level to collate them with a word dictionary is executed. Then, the paragraph recognition for assembling the paragraph based on results of the word recognition with regard to the syntax rule is executed. Then, the text recognition is executed by utilizing the wide-range knowledge such as the context, the meaning, etc. According to such process procedures, the precise voice recognition can be carried out. [0128] The memo information displayed on the memo screen based on the voice recognition, the databases (the phone book database, the destination database, etc.) constructed by the predetermined set items, the voice operation keywords used to execute processes of the predetermined operations such as the memo display start and the like by the voice recognition, and character extraction keywords used to extract the update information of the database from the character data that are subjected to the voice recognition are stored in the memory 23 a. [0129] The navi control portion 10 a causes the display device 18 to split/display the display screen 18 a into the memo screen and the navigation screen, and then reads the voice operation keyword stored in the memory 23 a. Thus, the voice that is received by the voice input portion 21 is subjected to the voice recognition by the voice recognition portion 24 . Then, if the navi control portion 10 a decides the character data, which is subjected to the voice recognition by the voice recognition portion 24 , coincide with the memo display starting keyword in the voice operation keywords, the navi control portion 10 a issues an instruction to the drawing/display control portion 17 a to display the character data, which is subjected to the voice recognition by the voice recognition portion 24 , on the memo screen. [0130] The drawing/display control portion 17 a starts the process of displaying the character data on the memo screen in a conversational form, based on the instruction issued from the navi control portion 10 a. [0131] Also, the navi control portion 10 a executes the process of storing the memo contents displayed on the memo screen into the memory 23 as the memo information, then reads the character extraction keyword from the memory 23 after the storing process, and then executes the process of extracting the character data, which relates to the character extraction keyword, from the memo information. Then, if the related character data are extracted, the process of updating the contents of the database, in which the set item associated with the character extraction keyword is provided, into the contents of the character data is executed. [0132] Also, the navi control portion 10 a executes the process of registering the voice operation keywords and the character extraction keywords, and can execute the display of the register screen, the setting of the register keywords, etc. [0133] [0133]FIG. 16 to FIG. 27 are views showing examples displayed on the display screen 18 a to explain utilization modes of the navigation apparatus according to the embodiment (2). [0134] [0134]FIG. 16 shows a display example in which the outgoing call of the communication portion 19 is detected while the navigation screen is being displayed to execute the route guidance to the destination. Outgoing call information 31 a indicating that the outgoing call is detected is displayed on the display screen 18 a. [0135] Then, when the navigation apparatus entered into the call mode, the display screen 18 a is shifted to the split display screen shown in FIG. 17. In the split display screen shown in FIG. 17, the display screen 18 a is split/displayed into a memo screen 32 a, on which the character data that are subjected to the voice recognition process can be displayed, and the navigation screen 33 , and then the voice that is received by the voice input portion 21 is voice-recognized. Then, if the received voice coincides with the voice operation keyword used to start the memo display based on the voice recognition, the display informing the user of the start of the voice recognition memo, for example, “the voice recognition memo is started” is displayed on the memo screen 32 a, and then the memo taken based on the voice recognition is started. [0136] [0136]FIG. 18 shows a situation where the voice recognition memo is displayed on the memo screen 32 a. The guide map for the guided routes is displayed continuously on the navigation screen 33 . The conversation memos that are subjected to the voice recognition are displayed on the memo screen 32 a, and the character data of the other person in communication (paragraph contents indicated by the ear mark) and the character data of the user (paragraph contents indicated by the mouth mark) are displayed. [0137] Then, when a “record” button displayed on the memo screen 32 a is touch-input, the contents displayed on the memo screen 32 a are stored into the memory 23 a as the memo information. Also, the character extraction keyword that is set previously is read from the memory 23 a, and then the process of extracting the information that are associated with the character extraction keyword from the memo information is executed. Then, if the update information of the database stored in the memory 23 a are contained in the memo information, the screen is shifted to a data extraction screen shown in FIG. 19. [0138] In the data extraction screen shown in FIG. 19, the name of the database in which the update information are contained (in this case, the “phone book database”), the name of the person who contains the update information, the update item, the update contents, and the operation buttons are displayed. [0139] Then, when a “DB update” button is touch-input, the database update process of rewriting the data into the displayed contents is executed. Then, after the update process of the database is executed, the display screen 18 a is switched from the split display screen consisting of the memo screen 32 a and the navigation screen 33 to one display screen of the navigation screen. [0140] Also, the user can register the voice operation keyword and the character extraction keyword stored in the memory 23 a. First, when a “voice operation keyword registration” button provided on the menu screen shown in FIG. 20 is touch-input, the screen is shifted to a “voice operation keyword registration” screen shown in FIG. 21. [0141] In the “voice operation keyword registration” screen shown in FIG. 21, a “general registration” button and an “individual registration” button are displayed. When the “general registration” button is touch-input, the screen is shifted to a “general registration” screen shown in FIG. 22. [0142] In the “general registration” screen shown in FIG. 22, the voice operation keyword that is common to all other persons in communication can be registered. In this case, a “start memo display” process for starting the display of memo by the voice recognition and a “terminate voice recognition” process for terminating the display of the voice recognition and the memo are listed the recognition process. The voice operation keywords corresponding to respective processes can be registered. [0143] For example, when a “start memo display” button shown in FIG. 22 is touch-input to register the voice operation keyword of the memo display starting process, the screen is shifted to a “keyword registration for start memo display” screen shown in FIG. 23. [0144] In the “keyword registration for start memo display” screen shown in FIG. 23, a list of the memo-display start keywords that are set previously is displayed. Then, when a display button on which the predetermined keyword is written is touch-input and also a “registration” button is touch-input, the memo-display start keyword is registered. [0145] Also, in the “voice operation keyword registration” screen shown in FIG. 21, when the “individual registration” button is touch-input, the screen is shifted to an “individual registration” screen shown in FIG. 24. [0146] In the “individual registration” screen shown in FIG. 24, the voice operation keywords can be registered individually in response to the other person to/from which the call of the communication portion 19 is issued/received (the other person in communication). First, when a “select registrant” button is touch-input, the screen is shifted to a “select registrant” screen (not shown). For example, when the names of the registrants (the names of the persons registered in the phone book database) are scroll-displayed and the name of the registrant that should be individually registered is touch-input, the screen returns to FIG. 24. Thus, the selected registrant name is displayed on the right side of the “select registrant” button. Also, the setting of the recognizing process, etc. can be executed in the same way as the method explained in FIG. 22 and FIG. 23. The voice operation keywords can be registered individually every registrant via the “individual registration” screen. [0147] Also, in the “menu” screen shown in FIG. 20, when a “character extraction keyword registration” button is touch-input, the screen is shifted to a “character extraction keyword registration” screen shown in FIG. 25. [0148] In the “character extraction keyword registration” screen shown in FIG. 25, the “general registration” button and the “individual registration” button are displayed, like the screen shown in FIG. 21. In FIG. 25, when the “general registration” button is touch-input, the screen is shifted to a “general registration” screen shown in FIG. 26. [0149] In the “general registration” screen shown in FIG. 26, a list of the character extraction keywords is displayed. In this case, the character extraction keywords that are listed are the keywords as the broader term, and the keywords as the narrower term are further associated with respective keywords. Accordingly, the information that relate to the set items of the database can be extracted from the memo information without omission. [0150] Then, when the character extraction keyword to be used is touch-input (a plurality of character extraction keywords can be set) and also the “registration” button is touch-input, the selected keyword is registered as the character extraction keyword that is common to all the other persons in communication. [0151] Also, in FIG. 25, when the “individual registration” button is touch-input, the screen is shifted to the “individual registration” screen of the character extraction keyword shown in FIG. 27. In the “individual registration” screen shown in FIG. 27, like the “individual registration” screen of the voice operation keyword shown in FIG. 24, when the “select registrant” button is touch-input to select the predetermined registrant from the “select registrant” screen (not shown), then the character extraction keyword for the individual registration that is listed in FIG. 26 is touch-input (a plurality of character extraction keywords can be set), and then when the “registration” button is touch-input, the selected keyword is registered as the character extraction keyword peculiar to the selected registrant. [0152] Next, processing operations of a memo function executed by the navi control portion 10 a in the navigation apparatus according to the embodiment (2) will be explained with reference to a flowchart shown in FIG. 28 hereunder. In this case, since processes in steps S 51 to S 54 are similar to the processes in steps S 1 to S 4 shown in FIG. 14, their explanation will be omitted herein. [0153] In step S 54 , the process of splitting/displaying the display screen 18 a into the memo screen 32 a and the navigation screen 33 shown in FIG. 17 is executed. Then, the process goes to step S 55 . In step S 55 , the process of reading the voice operation keyword from the memory 23 a is executed. Then, the process goes to step S 56 . [0154] In step S 56 , the process of starting the voice recognizing process that recognizes the voice data, which are received by the voice input portion 21 , and the voice data of the other person in communication, which are received by the communication portion 19 , as the character data is executed. Then, the process goes to step S 57 . [0155] In step S 57 , it is decided whether or not the voice, which is received by the voice input portion 21 and is subjected to the voice recognition by the voice recognition portion 24 , coincided with the voice operation keyword for the memo display start. If it is concluded that the voice does not coincide with the voice operation keyword for the memo display start, the process returns to step S 57 . In contrast, if it is concluded that the voice coincided with the voice operation keyword for the memo display start, the process goes to step S 58 . [0156] In step S 58 , the process of displaying the character data, which are subjected to the voice recognition, on the memo screen 32 a is executed. Then, the process goes to step S 59 . In step S 59 , it is decided whether or not the voice, which is received by the voice input portion 21 and is subjected to the voice recognition by the voice recognition portion 24 , coincided with the voice operation keyword used to end the voice recognition of the memo display. If it is concluded that the voice does not coincide with the voice operation keyword used to end the voice recognition, the process goes back to step S 58 . In contrast, in step S 59 , it is concluded that the voice coincided with the voice operation keyword used to end the voice recognition, the process goes back to step S 60 . [0157] In step S 60 , it is decided which one of the “record” button, which is used to store the memo contents displayed on the memo screen 32 a in the memory 23 a as the memo information, and the “cancel” button, which is used to cancel the memo information displayed on the memo screen, is touch-input. If it is concluded that the “record” button is touch-input, the process goes to step S 61 . In contrast, in step S 60 , it is concluded that the “cancel” button is touch-input, the process goes to step S 68 . [0158] In step S 61 , the process of storing the voice-recognized memo information into the memory 23 a is executed. Then, the process goes to step S 62 . In step S 62 , the process of reading the character extraction keyword from the memory 23 a is executed. Then, the process goes to step S 63 . In step S 63 , the process of extracting the character data, which relates to the character extraction keyword, from the character data that are subjected to the voice recognition is executed. Then, the process goes to step S 64 . [0159] In step S 64 , it is decided whether or not the update information of the database, which are stored in the memory 23 a, are contained in the extracted character data. If it is concluded that the update information of the database are contained, the process goes to step S 65 . In contrast, in step S 64 , if it is concluded that the update information of the database are not contained, the process goes to step S 68 . [0160] In step S 65 , the process of displaying the extracted update information of the database shown in FIG. 19 is executed. Then, the process goes to step S 66 . In step S 66 , it is decided which one of a “DB update” button and a “DB not-update” button displayed on the memo screen 32 a is touch-input. If it is concluded that the “DB update” button is touch-input, the process goes to step S 67 . In contrast, in step S 66 , if it is concluded that the “DB not-update” button is touch-input, the process goes to step S 68 . [0161] In step S 67 , the database updating process, i.e., the process of updating the database the contents of the set items in the database shown in FIG. 19 into the contents of the extracted character data is executed. Then, the process goes to step S 68 . [0162] In step S 68 , the process of switching the display screen 18 a, which is split into the memo screen 32 a and the navigation screen 33 , into one display screen of the navigation screen is executed. Then, the process is ended. [0163] Next, processing operations in the voice operation keyword registration executed by the navi control portion 10 a in the navigation apparatus according to the embodiment (2) will be explained with reference to a flowchart shown in FIG. 29 hereunder. [0164] First, in step S 71 , it is decided whether or not the “voice operation keyword registration” button is touch-input into the “menu” screen shown in FIG. 20. If it is concluded that the “voice operation keyword registration” button is not touch-input, the process is ended. In contrast, if it is concluded that the “voice operation keyword registration” button is touch-input, the process goes to step S 72 . [0165] In step S 72 , the process of displaying the “voice operation keyword registration” screen shown in FIG. 21 is executed. Then, the process goes to step S 73 . In step S 73 , it is decided which one of the “general registration” button and the “individual registration” button displayed on the display screen 18 a in FIG. 21 is touch-input. If it is concluded that the “general registration” button is touch-input, the process goes to step S 74 . [0166] In step S 74 , the process of displaying the “general registration” screen shown in FIG. 22 is executed. Then, the process goes to step S 75 . In step S 75 , the process of registering the general registration keyword, which corresponds to each recognizing process shown in FIG. 22, is executed based on the instruction that is input by the user. Then, the process goes to step S 76 . [0167] In step S 76 , it is decided whether or not the “end” button is touch-input. If it is concluded that the “end” button is not touch-input, the process is ended. In contrast, if it is concluded that the “end” button is touch-input, the process goes to step S 77 . [0168] In step S 77 , the process of updating/storing the voice operation keyword, which is generally registered newly, into the memory 23 a. Then, the process is ended. [0169] In contrast, in step S 73 , if it is concluded that the “individual registration” button is touch-input, the process goes to step S 78 . [0170] In step S 78 , the process of displaying the “individual registration” screen shown in FIG. 24 is executed. Then, the process goes to step S 79 . In step S 79 , the process of registering the registration keyword, which corresponds to the registrant selecting process and each recognizing process shown in FIG. 24, is executed based on the instruction that is input by the user. Then, the process goes to step S 80 . [0171] In step S 80 , it is decided whether or not the “end” button is touch-input. If it is concluded that the “end” button is not touch-input, the process is ended. In contrast, if it is concluded that the “end” button is touch-input, the process goes to step S 81 . [0172] In step S 81 , the process of updating/storing the voice operation keyword, which is individually registered newly, in the memory 23 a is executed. Then, the process is ended. [0173] In this case, the registration of the character extraction keyword is also carried out by the almost same processing operation as the processing operation explained as above. [0174] According to the navigation apparatus according to the above embodiment (2), when the incoming call or the outgoing call of the communication portion 19 is detected, the display screen 18 a is split/displayed into the memo screen 32 a and the navigation screen 33 . Then, the process of starting the memo display is executed when the voice input portion 21 receives the voice corresponding to the voice operation keyword. Then, the character data that are subjected to the voice recognition by the voice recognition portion 24 are displayed on the memo screen 32 a as the memo contents. Therefore, in order to take the notes, the user is not required to take out the writing paper, the writing tool, etc. every time and to prepare them previously. Thus, the user can take notes easily by the voice. Also, since the operation to use the memo function can be executed by the voice, the operability can be improved and also the convenience in use for the user can be further improved. [0175] Also, the voice data received via the voice input portion 21 and the voice data received via the communication portion 19 are recognized by the voice recognition portion 24 , and then stored in the memory 23 a as the character data. Therefore, the memory capacity can be reduced rather than the case where the voice data are stored as it is. Also, the voice-recognized character data can be practically used in the application such as the update of the database, etc. As a result, availability of the voice data can be enhanced. [0176] Also, since the user can register the voice operation keyword and the character extraction keyword that are common to the other person in communication, the generalization of the voice operation can be achieved. Also, since the common character data that are associated with the character extraction keyword are extracted from the memo information, the update of the database can be executed appropriately. Therefore, the labor required of the user to register registration items in the database by the separate inputting can be omitted, and the navigation apparatus becomes serviceable and convenient of use for the user. [0177] Also, the voice operation keyword and the character extraction keyword may be registered individually by the user according to the other person in communication. Also, this navigation apparatus may deal with various applications of the user by changing the voice operation keyword and the character extraction keyword according to the other person in communication. [0178] In this case, in the above embodiment (2), the case where the character data that are subjected to the voice recognition by the voice recognition portion 24 are displayed on the memo screen 32 a as the memo contents is explained. However, in another embodiment, the character recognition portion 22 explained in FIG. 1, the voice recognition portion 24 , an inputting portion that can select one of these recognizing portions may be provided. The screen may be switched into the memo screen on which memo contents can be input by the handwriting or the memo screen on which memo contents can be input by the voice, in response to the selection input of the user. [0179] In still another embodiment, the character recognition portion 22 , the voice recognition portion 24 , and a switching portion, which can switch automatically settings in these recognizing portions in response to the running situation, may be provided. The memo screen on which memo contents can be input by the voice may be set while the vehicle into which the navigation apparatus is installed is running. On the other hand, the memo screen on which memo contents can be input by the handwriting may be set during when the vehicle is stopped. [0180] [0180]FIG. 1: [0181] [0181] 10 navigation control portion [0182] [0182] 11 speed sensor [0183] [0183] 12 gyro sensor [0184] [0184] 14 GPS receiver [0185] [0185] 16 DVD drive [0186] [0186] 17 drawing/display control portion [0187] [0187] 18 b touch panel [0188] [0188] 19 communication portion [0189] [0189] 20 voice output portion [0190] [0190] 21 voice input portion [0191] [0191] 22 character recognition portion [0192] [0192] 23 memory [0193] [0193]FIG. 13 [0194] S 1 Is “outgoing call” or “incoming call” detected? [0195] S 2 display “outgoing call” or “incoming call” [0196] S 3 Is a system in a call mode? [0197] S 4 process of split-displaying a display screen [0198] S 5 memo drawing/displaying process [0199] S 6 Is call mode ended? [0200] S 7 “record” button or “cancel” button? [0201] S 8 character recognition process [0202] S 9 display the recognized character [0203] S 10 Is a touch input of a “OK” button given? [0204] S 11 process of storing memo information into a memory [0205] S 12 process of searching update information [0206] S 13 Is the update information contained? [0207] S 14 display a database update indication screen [0208] S 15 “update” button or “not update” button? [0209] S 16 display an update information check screen [0210] S 17 Is a touch input of an “OK” button given? [0211] S 18 process of updating the database [0212] S 19 display a navigation screen [0213] S 20 Is a touch input of a “correction” button given? [0214] S 21 correction process [0215] S 22 Is a touch input of a “correction” button given? [0216] S 23 correction process [0217] [0217]FIG. 14: [0218] S 31 Is a touch input of a “database correction” button given? [0219] S 32 display a selection screen of the correcting database [0220] S 33 Is a touch input given to a correcting database? [0221] S 34 display a correction screen of the database [0222] S 35 Is a touch input of the name given? [0223] S 36 display a correction item selection screen [0224] S 37 Is a touch input of the correction item given? [0225] S 38 display an item correction screen [0226] S 39 process of displaying input corrected content [0227] S 40 Is a touch input of an “end” button given? [0228] S 41 process of updating the corrected content of the set item [0229] [0229]FIG. 15: [0230] [0230] 10 a navigation control portion [0231] [0231] 11 speed sensor [0232] [0232] 12 gyro sensor [0233] [0233] 14 GPS receiver [0234] [0234] 16 DVD drive [0235] [0235] 17 a drawing/display control portion [0236] [0236] 18 b touch panel [0237] [0237] 19 communication portion [0238] [0238] 20 voice output portion [0239] [0239] 21 voice input portion [0240] [0240] 23 a memory [0241] [0241] 24 voice recognition portion [0242] [0242]FIG. 18: [0243] (1) Hallo! This is Harada. [0244] (2) Hallo! This is Tanaka. Where are you now? [0245] (3) I come up close to you. Let me have your address. [0246] (4) OK. 1-1-1, ΔΔ-machi, Kobe-shi. [0247] (5) Thank you. I call you when I arrive there. [0248] [0248]FIG. 28: [0249] S 51 Is “outgoing call” or “incoming call” detected? [0250] S 52 display “outgoing call” or “incoming call” [0251] S 53 Is a system in a call mode? [0252] S 54 process split-screen displaying [0253] S 55 process of reading a voice operation keyword [0254] S 56 voice recognition process [0255] S 57 Does the recognized voice coincide with the voice operation keyword for starting memo display? [0256] S 58 process of displaying the voice-recognized character data [0257] S 59 Does the recognized voice coincide with the voice operation keyword for terminating the memo input? [0258] S 60 “record” button or “cancel” button? [0259] S 61 process of storing memo information into memory [0260] S 62 process of reading a character extraction keyword [0261] S 63 process of extracting character data [0262] S 64 Is the update information of database contained? [0263] S 65 display the update information [0264] S 66 “update DB” or “not update DB”? [0265] S 67 process of updating the database [0266] S 68 display a navigation screen [0267] [0267]FIG. 29: [0268] S 71 Is a touch input of the “speech operation keyword registration” button given? [0269] S 72 display a voice operation keyword registration screen [0270] S 73 “general registration” button or “individual registration” button? [0271] S 74 display a general registration screen [0272] S 75 process of registering a general registration keyword [0273] S 76 Is a touch input of the “end” button given? [0274] S 77 process of storing the general registration keyword [0275] S 78 display an individual registration screen [0276] S 79 process of registering an individual registration keyword [0277] S 80 Is a touch input of the “end” button given? [0278] S 81 process of storing the individual registration keyword

A communication device for communicating with an external is connectable to a navigation apparatus. The navigation apparatus includes a display portion, an input portion for inputting memo information, an outgoing/incoming call determination portion, and a display control portion for controlling the display portion. The outgoing/incoming call determination portion determines whether or not the communication portion conducts an outgoing call and determining whether the communication portion receives an incoming call. When the outgoing/incoming call determination portion concludes that the communication portion conducts the outgoing call or that the communication portion receives the incoming call, the display control portion splits the display portion into a memo screen on which content of the memo information is displayed and a navigation screen.

FIELD OF THE INVENTION [0001] The present invention relates to cultivation chambers and methods for the production of photosynthetic organisms, in particular algae and including microalgae and macro algae. BACKGROUND OF THE INVENTION [0002] The culturing of photosynthetic organisms, particularly microalgae and cyanobacteria, has become the focus of much interest due to the multiple applications for such microorganisms. Firstly, the culturing of photosynthetic microorganisms can utilise waste carbon dioxide (CO 2 ) and nutrients (for example from sewerage or agriculture outputs) and, in the presence of light, convert these into biomass. Secondly, the produced biomass has the potential for a multitude of uses including: the extraction of oils, which may then be converted into biodiesel; as raw materials for the bioplastics industry; to extract nutraceutical, pharmaceutical and cosmetic products; for animal feed and as feedstock for jetfuel, pyrolysis and gasification plants. [0003] The present invention aims to address one or more of the difficulties of the systems known in the art for culturing photosynthetic organisms, particularly algae. SUMMARY OF THE INVENTION [0004] In a first aspect, the present invention provides a biological cultivation system for the culture of photosynthetic organisms including at least one cultivation chamber permitting exposure of the culture medium to natural and/or artificial light and including; a light transmissive wall or walls defining a gas space; and a culture medium containment area below the gas space; one or more fluid inlets positioned within the culture medium containment area; and one or more gas outlets in communication with the gas space; a control unit operatively connected to a gas flow control device, the gas flow control device controlling the flow of gas in through the fluid inlets and out through the fluid outlets to control the conditions within the cultivation chamber. [0012] In an embodiment, the biological cultivation system may further include a plurality of cultivation chambers. This permits both flexibility of production and centralisation of system control. The cultivation chambers may be interconnected, e.g. via a manifold means, in series or in parallel. Preferably 10 to 200 cultivation chambers may be joined; more preferably 20 to 60. The cultivation chamber array may include use with parallel like-configured vessels or a combination of 2 or more dissimilar growth medium vessels. This may include, but is not limited to, multiple cultivation chambers in parallel or a combination of bags and open raceways. [0013] Thus, in an alternative embodiment of the present invention, the biological cultivation system may further include a plurality of cultivation chambers wherein the cultivation chambers include one or more chambers formed of a flexible material; and one or more chambers including a pair of opposed substantially rigid walls enclosed by a light transmissible section. [0016] The rigid cultivation chamber(s) may permit the cultured organisms to be rested in comparatively low light where required. The rigid cultivation chamber may also include the control unit as described above and a balance tank. [0017] In a further aspect of the invention, there is provided a method of cultivating photosynthetic organisms may include: (a) providing a cultivation chamber including: (i) at least one light transmissive wall or walls defining: a gas space; and a culture medium containment area below the gas space; (ii) one or more gas inlets and one or more gas outlets in communication with the gas space; (iii) one or more fluid outlets and outlets communicating with the culture containment are; and (iii) a gas flow control means; (b) introducing into the cultivation chamber a culture medium and an inoculate of photosynthetic organisms, the cultivation chamber permitting exposure of the culture medium to a natural and/or artificial light; (c) controlling the flow of gas in through the gas inlets and out through the gas outlets using the gas flow control device, wherein the flow of gas drives evaporation from the culture medium and/or controls the temperature of the cultivation chamber; and (d) allowing the photosynthetic organisms to grow in the presence of light. [0028] In one embodiment, the cultivation chamber includes one or more fluid ports to allow for the introduction and removal of the culture medium. Preferably, the one or more fluid ports include a regulator to control the introduction and removal of the culture medium from the cultivation chamber. More preferably, the regulator is a valve, preferably a ball valve. [0029] Photosynthetic organisms convert carbon dioxide, water and nutrients into biomass in the presence of light. Therefore, the growth of these photosynthetic organisms enables carbon dioxide emitted as, for example, flue gas from a power plant, refinery or cement kiln, liquid natural gas production or coal seam gas, to be recycled as biomass rather than being released into the atmosphere. The conditions controlled within the cultivation chamber include the pH and CO 2 content of the culture medium, the evaporation rate and temperature in the cultivation chamber. Adding gases rich in CO 2 into an algal slurry decreases the pH of the solution/slurry. As CO 2 is consumed the pH will increase. Therefore by balancing the rate of supply of CO 2 and consumption of CO 2 , a stable and optimal pH can be maintained which ensures adequate carbon concentrations are available for photosynthesis to take place and new bio-material to be formed as cells grow and multiply. [0030] The fluid inlets for the culture medium containment area are positioned along a base portion of the culture medium containment area. [0031] The photosynthetic organisms are selected from the group consisting of macroalgae, microalgae and cyanobacteria. Preferably the photosynthetic organisms are microalgae. [0032] The concentration of CO 2 introduced may be varied by varying the amount of air mixed with the CO 2 . For example, CO 2 -containing flue gas may be diluted with air, depending on the CO 2 requirements of the photosynthetic organisms. During periods of darkness, for example at night when natural light is used, the amount of CO 2 may be decreased while maintaining a constant gas flow by increasing the amount of air in the mixture. The air to be mixed with the CO 2 source may be filtered to remove certain particulate matter, for example using a particulate air filter, more preferably a high efficiency particulate air (HEPA) filter. [0033] The culture medium may be any suitable medium for the growth of the desired photosynthetic organisms. The culture medium may be based on fresh or saline water and may include waste water from industrial processes or sewerage treatment systems. The culture medium may include additional nutrients including iron sulphate and the like. [0034] The photosynthetic organisms may be selected from any suitable organisms and may be cultured as a single species in monoculture or two or more species in the same cultivation chamber. A polyculture is preferred as this may provide resilience to changes in the environment due to e.g. temperature, make-up of nutrients and salinity Photosynthetic organisms that produce useful ingredients for the chemical, biodiesel, pharmaceutical or nutraceutical industries are preferred. Suitable photosynthetic microorganisms include cyanobacteria (blue-green algae) and algae, preferably microalgae or macroalgae. The microorganisms may grow in fresh or salt water. Examples of photosynthetic microorganisms that may produce useful ingredients/feedstocks include, but are not limited to, those belonging to the following genera: Chiamydomoas; Chaetoceros; Dunaliella; Haematococcus; Isochrysis; Nannochloropsis; Porphyridum; Picochlorum (synonym Nannochloris ); Pleurochrysis; Rhodomoas, Spriulina. [0035] A preferred microalgal strain may be a fast growing strain. The strain may exhibit high lipid content and be salinity tolerant. A Nannochloropsis strain or mixture of strains is particularly preferred. The method of the present invention may also be utilised to culture macroalgae, for example those of the genera Ulva, Cladophora; Chaetomorpha . or Oedoginium. [0036] The photosynthetic organisms produced according to the present invention have a number of potential uses. Oil (e.g. triglycerides) may be extracted from the microorganism and this oil may be used for: biodiesel production (e.g., using known transesterification processes); as a raw material for the production of plastics and for the synthesis of jet and other fuels. The cake component of the biomass that is left after the extraction of oil may be used as: feed for the livestock industry; fertilizer production; biomass for bio-plastic production or biomass for energy and jet fuel production and/or pyrolysis. Photosynthetic organisms may also produce other useful products, such as nutraceuticals (e.g. omega 3 and 6 fatty acids; antioxidants, such as astaxanthin and pigments, such as β-carotene), phycocolloids, triglycerides and other ingredients for the pharmaceutical and cosmetics industries. [0037] In a preferred embodiment, fluid inlets are positioned along a base portion of the culture medium containment area. The first and/or second gas may be an oxygen-containing gas, e.g. air. The second gas may be the same as, or different to the first gas. The first gases may include carbon dioxide (CO 2 ). Where CO 2 is included, the gas may function to provide carbon to the photosynthetic system and/or reduce the pH of the circulating fluid, e.g. water. [0038] In one embodiment, one or more walls of the cultivation chamber is(are) composed of a flexible material, which may allow for the inflation of the cultivation chamber. Within the context of the invention, a flexible material is a pliable material which does not have a rigid shape. Such a flexible material includes, but is not limited to, a plastic-type film. In a preferred embodiment, the cultivation chamber is in the form of an enclosed flexible plastic structure of tube-like configuration, such as a plastic bag-type structure. In a preferred embodiment, one or more walls of the cultivation chamber are light-transmissible and the walls may be integrally formed in a tubular shape. The cultivation chamber is preferably horizontally oriented producing a flat base. The base preferably has a slope of 1-5° towards the discharge end of the chamber. This assists the flow of cultured algal slurry towards the discharge outlet. [0039] The plastic-type film may be selected to permit transmission of light at a pre-determined wavelength. A polyethylene film, e.g. a linear low density polyethylene film and/or medium density film may be used. The plastic-type film may include pigments e,g. mineral oxides, such as titanium and/or ferric oxides, and/or other light controlling additives to permit control of light transmission. In one embodiment a material permitting UV light transmission of approximately 20% to 65%, preferably 25% to 60%, may be used. [0040] In a more preferred embodiment, the cultivation chamber is inflatable. Where the cultivation chamber is inflatable, the inflation of the cultivation chamber may be maintained by the flow of gas achieved through the introduction of gas into the chamber through the gas inlets and out through the gas outlets. The gas may be introduced into the cultivation chamber through one or more gas inlets positioned above and/or below the surface of the culture medium. [0041] In a further preferred embodiment, the cultivation chamber may include a pair of opposed substantially rigid side walls; and a light-transmissible section connecting and providing a canope enclosing the side walls. [0044] The use of substantially rigid side walls may improve the strength and longevity of the cultivation chamber(s). The side walls may include a pair of opposed bulkheads, e.g. steel bulkheads. [0045] Thus, in an alternative embodiment of the present invention, the biological cultivation system may include a plurality of cultivation chambers wherein the cultivation chambers include one or more chambers formed of a flexible material; and one or more chambers including a pair of opposed substantially rigid walls enclosed by a light transmissible section. [0048] Whilst the direct control of light transmissibility in the light-transmissible sections of the cultivation chamber may limit photoinhibition of the growth of the photosynthetic organisms, additional light control may be required during particular seasons and/or particular times of the day. Accordingly, the cultivation chamber may further include a secondary light control device. The light control device may be of any suitable type. The secondary light control device may be fixed and/or variable. A shade or filter, such as a shade sail or cloth may be provided. [0049] Light level shading may be fixed due to pre-calculated geographic characteristics of ambient light levels. [0050] Shading may be variable via external light permeable covers such as shade sails due to variable geographical and chronological ambient light conditions. Variable parameters that dictate a variable control of shading would be but are not limited to: (i) time of day and sunlight intensity (ii) geographic latitude and/or (iii) actual light requirement of an individual species of algae strain both macro and micro varieties of algae within a controlled growth process. [0054] Preferably a number of fluid inlets are positioned throughout the cultivation chamber. In a preferred embodiment, the fluid inlets are positioned at the base of the cultivation chamber, preferably along the length of the base of the cultivation chamber. [0055] In a further preferred embodiment, fluid inlets are positioned along conduits at the base of the cultivation chamber, wherein the conduits are adapted to carry and distribute the flow of gas. The gas inlets are preferably positioned along the conduits at intervals that allow for a substantially even distribution of gas flow along the length of an elongated cultivation chamber. The gas outlets may be designed to release excess gas pressure that may build up in the flexible cultivation chamber. [0056] In a preferred embodiment, the gas outlets may include a valve system, preferably a one-way valve system. The use of one-way valves may reduce the risk of contamination of the cultivation chamber from outside air, whilst permitting removal of excess oxygen etc. [0057] In a further embodiment, gas is passed into the cultivation chamber through fluid inlets both above the surface of the culture medium. and below the surface of the culture medium. The introduction of the gas above the surface of the culture medium allows for a modification of the atmosphere in the cultivation chamber. [0058] Cultures of any kind and in any embodiment can become contaminated by rogue (unwanted organisms. Accordingly, in a preferred aspect of the present invention, the method may further include providing an effective amount of a selective biocide; and treating the culture medium with the selective biocide to reduce or eliminate growth of unwanted organisms. [0061] The unwanted organism may be a parasite, bacterium, fungal or algal strain. The biocide may accordingly include a pesticide, bactericide, fungicide or algaecide or a combination thereof. [0062] A source of light is required for the organisms to photosynthesise. Any suitable source of light may be used including natural light and artificial light or a combination of natural and artificial light. Artificial light may be provided by any suitable light source. In one embodiment, the artificial light source is provided by light-emitting diodes (LEDs). An artificial light source may be provided to extend the length of time per day that the organisms continue to photosynthesise beyond daylight hours. Accordingly, in one embodiment, the cultivation chambers and methods of the present invention are adapted to alternate between using natural and artificial light as required. [0063] In a further preferred aspect of the present invention, the method of cultivating photosynthetic organisms where the cultivation chamber further includes a gas flow control device; the method further including the step of controlling the flow of gas in through the fluid inlets and out through the fluid outlets using the gas flow control device, wherein the flow of gas drives evaporation from the culture medium and/or controls the temperature of the cultivation chamber. The gas flow control device is preferably a fan. The gas flow control device is preferably situated at one end of an elongate cultivation chamber. The gas flow control device may function to create a positive atmospheric displacement differential between the liquid culture medium and the gas space. This may function to retard the escape of the first gas, e.g. a CO 2 -containing gas from the culture medium and increase its residence time in the culture medium. The longer residence time of e.g. CO 2 may assist in efficient dosing of the culture medium to enhance algal growth. [0064] When using an enclosed bioreactor that is not open to the atmosphere, usage of a positive pressure displacement differential between the liquid medium and the enclosed atmospheric space above the liquid interface area may function to retard the escape of CO 2 out of solution of the growth medium liquid. The longer residence time of CO 2 in water solution will assist in more efficient dosing of CO 2 for algae growth and less CO 2 to escape to atmosphere without being taken up by algae growth. [0065] Improved atmospheric pressure control is thus achieved by: (i) metering of gas delivery volume within the bag/bioreactor on the delivery feed side and (ii) excess gas pressure being released from air gap above liquid medium via pressure release mechanisms such as either controllable or fixed pressure point relief valves. [0068] It has been found that evaporation from the culture medium may enable a degree of control over the temperature within the cultivation chamber. This assists in the culture of the microorganisms, as temperature control is important to gaining optimal growth and/or optimal production of the relevant chemicals by the microorganisms (such as triglycerides as ingredients for biodiesel). [0069] In a preferred embodiment, the gas flow control device further includes a temperature control. It has been found that a cultivation chamber, e.g. a photo-bioreactor, which is an enclosed unit, may suffer from a so called “greenhouse effect”. The exposure to light may result in an unacceptable increase in temperature within the chamber which may inhibit algal growth or even kill the algae. [0070] The temperature control may function to lower or raise the temperature of the cultivation chamber. The temperature control may include an evaporative cooling or air conditioning system. The temperature control may include a heat exchange system. [0071] To counteract any unwanted salinity increases associated with the evaporation of the water from the culture medium, additional water may be added to the culture medium. This additional water may be in any suitable form, for example as fresh water or aquaculture waste water. [0072] A further mechanism for controlling the temperature of the culture medium using the above aspects of the present invention is to control the rate at which gas is introduced into the cultivation chamber and/or the temperature of the introduced gas. For example, heat loss at lower than optimal ambient temperatures may be reduced by lowering the amount of gas at a temperature lower then ambient temperature being introduced into the culture medium, thereby reducing the mixing of the medium and resultant heat exchange. Accordingly, in darkness the gas flow may be reduced and may be stopped completely, to at least partially maintain the temperature of the cultivation medium during low night time ambient temperatures. [0073] Furthermore, by varying the temperature and composition of the gas introduced into the cultivation chamber the temperature of the liquid culture medium may be varied. For example, if using enriched CO 2 from flue gas as an input, the flue gas may be maintained at a higher temperature to counteract the effect of low ambient temperatures. Accordingly, the flue gas may be introduced at a higher temperature where the temperature of the culture medium needs to be increased. Conversely, where the temperature of the liquid culture medium needs to be reduced, the flue gas may be cooled further before introducing to the cultivation chamber. [0074] Alternatively, increasing the amount of air introduced into the cultivation chamber may aid in the cooling of the cultivation medium. This air may be introduced by bubbling from under the surface of the cultivation medium or by being passed over the surface of the cultivation medium. [0075] Alternatively, the temperature of the cultivation medium may be controlled by circulating it directly or indirectly over a suitable heat exchanger, such a cooling tower or a boiler. [0076] The cultivation chamber may be of any suitable size to cultivate the required amount of the photosynthetic organisms. [0077] In a preferred embodiment, the cultivation chamber may be about 1 metre to about 10 metres, more preferably about 2 metres to about 6 metres in width. In a particularly preferred embodiment, the cultivation chamber of the present invention is about 3 metres in width. [0078] In an alternative embodiment, the cultivation chamber may be about 5 metres to about 250 metres, more preferably about 10 metres to about 100 metres in length. In a particularly preferred embodiment, the cultivation chamber is about 50 metres in length. [0079] In one embodiment, the level of the culture medium in the cultivation chamber is controlled by the regulation of the intake of culture medium through one or more liquid ports, which act as inlets and/or outlets for the passage of liquid into and out of the cultivation chamber. It has been found that improved photosynthetic culture may be achieved by limiting the flow rate of culture medium through the cultivation chambers. This is possible as a consequence of permitting the gas to pass through the culture medium and thus provide adequate mixing thereto, [0080] Accordingly, in a further aspect, the control unit may further include [0000] a culture medium input system; the cultivation chamber being flow-connected to the control unit the liquid inlets and outlets permitting controlled circulation of the culture medium. [0081] The passage of the culture medium through the fluid ports in one or both directions is preferably regulated by one or more valves. The valves may be controlled by the control unit or may be externally controlled valves. The valves may be reactive to the level of the culture medium in the cultivation chamber, thereby allowing for the emptying (for example, for harvesting the photosynthetic organisms) and refilling of the cultivation chamber. Alternatively or in addition, the valves may be reactive to the concentration of algae generated in the growth column array. In a preferred embodiment the valves are ball valves. [0082] In a further embodiment, the level of the culture medium in the cultivation chamber is measured by means of one or more sensors. [0083] The control unit may further include a balance tank for maintaining fluid flow; and optionally a sampling unit to permit testing of the culture medium. [0086] The sampling unit may further provide an input feed device. The input feed device may provide a single location for nutrient addition and/or other dosing tasks. In a preferred embodiment where a source of a selective biocide is provided, this biocide may be added via the input feed device. [0087] Usage of a single location within an identified process of algae growth and harvesting to perform input feed or dosing tasks and process control function for a parallel grouped array of multiple ponds, growth column arrays, photobioreactors (PBR's), cultivation chambers, open raceways and other algae growth medium water retention vessels may significantly simplify unit design and function. [0088] In a particularly preferred embodiment, control unit may include drive controller(s) in combination with a programmable logic control (PLC). In this embodiment, the drive controller may function to control both culture growth and pump control. (a) The control unit may include a vector based combination drive and input/output (I/O) interface to combine pump and process control function. (b) The combination drive and process controller has the capability to be presented/programmed in either conventional PLC (programmable logic control-ladder configuration or function block based presentation) or background depicted decompiled firmware programming to an integrated circuit chip that cannot be edited beyond normal MMI/HMI presented operator changeable parameters. (c) Programming languages specifically intended are; (Function block diagram), LD (Ladder diagram), ST (Structured text), IL (Instruction list, similar to assembly language) and SFC (Sequential function chart), and modular programming. (d) The VSD controller may include a DSP (digital signal processor) that can operate concurrently as a PLC CPU (central processor unit) for required algae growth process control and as a variable speed pump controller. (e) A single master DSP may also control multiple slave pump controller and growth controller units. [0094] The control unit may be designed to function on AC and/or DC power input. The control unit may accordingly further provide for an AC input to DC bus, e.g. via a rectifier of an inverter to AC output. [0095] The control unit may further include a drive controller(s) to control the pumping rates of the culture medium. Preferably the drive controller(s) are variable speed drive controllers (VSP). Variable speed drives to control pumps both AC and DC powered allow variable pumping rates of algae growth medium for use in process control. The pumping rates of water may be varied upon growth requirements or harvesting/make up Input/output (I/O) Variable Frequency Drives (VFD), Pulse width modulated (PWM) and/or Vector type pumping drive controllers. DC drive controllers can be either variable voltage control or with pulse width modulation. [0096] It has been found that it is preferable to ‘starve’ the organisms of nutrients for a period, e.g. of 1 to 5 hours, prior to harvesting to increase overall lipid content achieved. [0097] Accordingly, the method of the invention further includes the steps of reducing or eliminating the nutrient content of the culture medium for a pre-determined period; and harvesting the photosynthetic organisms. [0100] The biological cultivation system for the culture of photosynthetic organisms may further include (i) at least one vertically oriented growth column including a light transmissible conduit; one of more fluid inlets in communication with the conduit; and one or more fluid outlets; and wherein a fluid outlet of the growth column is flow-connected to a fluid inlet of the cultivation chamber. [0105] It has been found that by utilising the vertical growth column, the growth efficiency of the biological cultivation system may be significantly improved. [0106] According to a further aspect, there is provided a biological cultivation system for the culture of photosynthetic organisms including: [0000] (i) a vertically oriented growth column including a light transmissible conduit; one of more fluid inlets in communication with the conduit; and one or more fluid outlets; and (ii) a cultivation chamber permitting exposure of the culture medium to natural and/or artificial light and including; a light transmissive wall or walls defining a gas space; and a culture medium containment area below the gas space; one or more fluid inlets positioned within the culture medium containment area; and one or more gas outlets in communication with the gas space; wherein a fluid outlet of the growth column is flow-connected to a fluid inlet of the cultivation chamber. [0116] It has been found that by utilising the vertical growth column, the growth efficiency of the biological cultivation system may be significantly improved. [0117] In a preferred form of the invention, the light transmissive conduit includes a light transmissive inner conduit and a light transmissive outer conduit surrounding and in fluid communication with the inner conduit. In order to establish a flow circulation system, it is preferable for the fluid inlet or inlets for the vertical growth column to be provided to either of the inner or outer conduits and the fluid outlets provided to the other of the inner or outer conduit. In this way, biomass, media and gas passes up either the inner or outer conduit and the biomass and media then descends down the other of the inner or outer conduit. In circumstances where the biomass density is increased during the up-flow to affect the intensity of light reaching the biomass, preferably the biomass and media travel up the outer conduit and down the inner conduit. [0118] Suitable gases and/or liquid nutrients may be introduced into the vertical growth column and cultivation chamber of the present invention to aid the growth of the photosynthetic organisms. Such gases or liquids may be selected from carbon dioxide (CO 2 ); fertilisers and waste from aquaculture and agriculture (for example: trout, salmon, cattle, pig and chicken farms). The CO 2 may be from any suitable source and may be from air or in a concentrated form. Examples of suitable concentrated sources of CO 2 include, but are not limited to, flue gases, kiln and incineration gases and gases from anaerobic digestion. In a preferred embodiment, the source of CO 2 is a flue gas, more preferably desulphured flue gas (DFG). [0119] In the preferred embodiment in which a growth column or columns is/are included in the biological cultivation system, the culture medium may include a concentrated slurry containing a mixture of culture medium and photosynthetic organisms (e.g. an algal slurry). The culture medium may include selected nutrients and/or trace elements to enhance growth. For example a culture medium including iron sulphate has been found to enhance algal growth. [0120] The method of the invention may further include the steps of (a) providing (i) a vertically oriented growth column including a light transmissive conduit; and (b) introducing into the vertical growth column, a culture medium and an inoculate of photosynthetic organisms; (c) introducing a first gas into the vertical growth column; and allowing the photosynthetic organisms to grow in the presence of light; (d) introducing the product of step (c) into the cultivation chamber, the cultivation chamber permitting exposure to natural and/or artificial light; (e) introducing a first gas through the inlet(s) within the containment area, wherein the flow of gas thereby mixes the culture medium; (f) introducing a second gas through the gas inlet(s) into the gas space, wherein the second gas functions to control the temperature of the gas space; and (g) allowing the photosynthetic organisms to grow further in the presence of light. [0129] According to a further aspect, there is providing a method of cultivating photosynthetic organisms including the steps of: (a) providing (i) a vertically oriented growth column including a light transmissive conduit; and (ii) a cultivation chamber including a wall or walls defining a gas space and a culture medium containment area below the gas space; (b) introducing into the vertical growth column, a culture medium and an inoculate of photosynthetic organisms; (c) introducing a first gas into the vertical growth column; and allowing the photosynthetic organisms to grow in the presence of light; (d) introducing the product of step (c) into the cultivation chamber, the cultivation chamber permitting exposure to natural and/or artificial light; (e) introducing a first gas through the inlet(s) within the containment area, wherein the flow of gas thereby mixes the culture medium; (f) introducing a second gas through the gas inlet(s) into the gas space, wherein the second gas functions to control the temperature of the gas space; and (g) allowing the photosynthetic organisms to grow further in the presence of light. [0139] The biological cultivation system as described above includes a vertically oriented growth column which may be substantially filled with a culture medium inoculated with a selected photosynthetic organism or mixture of organisms. The vertically oriented growth column may include an inner and an outer conduit. [0140] Gas may be passed into the base of the inner conduit via the gas inlets and may be bubbled into the culture medium. The introduction of gas allows for the mixing of the culture medium and assists in the distribution of the gases, nutrients, light and heat throughout the culture medium. In a preferred embodiment, a first gas is introduced in a substantially continuous manner while the photosynthetic organisms are photosynthesising (in the presence of light). The gas flow also permits movement of culture medium from the inner conduit to the outer conduit. This improves the exposure of the organisms to light as the concentration of organisms increases during growth. [0141] The first and/or second gas may be an oxygen-containing gas, e.g. air. The second gas may be the same as, or different to the first gas. The first gas may include carbon dioxide (CO 2 ). Where CO 2 is included, the gas may function to provide carbon to the photosynthetic system and/or reduce the pH of the circulating fluid, e.g. water. [0142] In a preferred embodiment of the present invention, an array of vertical growth columns may be used. The vertical growth columns may be the same or different. One or more vertical growth columns may include a light transmissible inner conduit and a light transmissible outer conduit, and/or one or more growth columns may include a single light transmissible column. [0143] The vertical growth columns may be arranged in any suitable manner. The columns may be arranged in series or in parallel. When in series, the algal slurry from one column becomes the feedstock for an adjacent column. The concentration within the slurry may thus increase throughout the array. [0144] Once a selected concentration of e.g. algae is achieved, the algal slurry may be passed through the fluid outlet(s) to the cultivation chamber. Typically the growth columns can sustain growth of algae between 30-75 grams dry weight (DW) per square meter compared to 20-35 grams DW per square meter for the cultivation chambers. [0145] Gas may then be passed into the cultivation chamber via the fluid inlets. Where the fluid inlets are situated below the surface of the culture medium containing the photosynthetic organisms, gas may be bubbled into the culture medium. The introduction of gas below the surface of the culture medium allows for the mixing of the culture medium and assists in the distribution of the gases, nutrients, light and heat throughout the culture medium. In a preferred embodiment, a first gas is introduced in a substantially continuous manner while the photosynthetic organisms are photosynthesising (in the presence of light). [0146] Accordingly, in a further aspect the present invention provides a product extracted from photosynthetic organisms produced in accordance with the method of the present invention. In one embodiment, the product is selected from the group consisting of an oil; glycerol; omega 3 and 6 fatty acids; astaxanthin; and 6-carotene. In another embodiment, the product is biomass cake, such as algae cake. [0147] Where the cultivation chamber is inflatable, gas outlets may be provided above the level of the cultivation medium to release the pressure that is built up through the gas which has been bubbled through the cultivation medium, for example from the base of the cultivation chamber. [0148] Accordingly, in a further aspect the present invention provides a method for the conversion of carbon dioxide to algal biomass including the steps of: cultivating algal photosynthetic organisms by the method described above in the presence of light wherein the second gas is carbon dioxide. [0150] In a further aspect, the present invention provides a method of recycling emitted carbon dioxide by utilising the emitted carbon dioxide as an input in the production of photosynthetic organisms using the method of the present invention. The emitted carbon dioxide may be flue gas, kiln gas, incineration gas and gas from anaerobic digestion. [0151] Where the CO 2 is provided from flue gas, the flue gas is preferably cooled and partly scrubbed of pollutants such as SOx, dust, heavy metals etc before it is introduced into the cultivation chamber. Heavy metals, SOx and dust remaining in the flue gas after partial scrubbing may provide micronutrients required for the growth of the photosynthetic organism. Such micronutrients may then be added to the culture medium, either directly or with additional treatment, e.g. the selective removal of heavy metals. [0152] In a further aspect of the present invention there is provided a method for the separation of concentrated microorganism biomass from a slurry of biomass in an aqueous media into fractions including the steps of: (1) providing concentrated microorganism biomass having substantially intact cells; (2) homogenising the biomass using a mechanical homogeniser to disrupt the cells of the microorganisms; and (3) separating the homogenised biomass into fractions. [0156] In a further aspect of the invention, there is provided a photosynthetic growth system including a plurality of cultivation chambers arranged in two or more sections, wherein the sections are connected in series and the cultivation chambers in each section is of a greater volume/capacity than the cultivation chambers of the previous section in the series or the total volume/capacity of cultivation chambers in each section is greater than the previous section. [0157] In a preferred embodiment of this aspect, the cultivation chambers in the first section may be vertical growth columns as described above and the subsequent sections may include any of the cultivation chambers described earlier. In each section, the cultivation chambers may be connected in parallel or in series. A further aspect of the invention may include a method of producing a photosynthetic organisms in the system including a plurality of sections as described above. DETAILED DESCRIPTION OF THE DRAWINGS [0158] FIG. 1(A) is a front view bag cultivation chamber according to a first embodiment and [0159] FIG. 1(B) is a side view of the embodiment of FIG. 1(A) [0160] FIG. 2(A) is a front view of a second embodiment of the bag cultivation chamber and [0161] FIG. 2(B) is a side view of the embodiment of FIG. 2(A) [0162] FIG. 3(A) is a front view of a third embodiment of a bag cultivation chamber and FIG. 3(B) is a side view of the embodiment of FIG. 3(A) [0163] FIG. 4 is a top view the embodiment of FIG. 3(A) [0164] FIG. 5 is a graph of Cell density (cells mL-1) from day 1 (inoculation) to day 20. Average±standard deviation, n=3. [0165] FIG. 6 is a graph showing the time course of nutrient concentrations in the bag cultivation chamber. A) nitrite, B) nitrate (red squares) and phosphate (black triangles). Average±standard deviation, n=3. [0166] FIG. 7 is a graph of the fluctuation of A) pH, B) temperature; and C) conductivity over culture time of Nannochloropsis oculata in the bag. WP-81: handheld TPS pH- and conductivity-meter, manual: handheld thermometer. [0167] FIG. 8 is a schematic diagram illustrating a series of cultivation chambers with central control unit. [0168] FIG. 9 is a schematic diagram illustrating a plurality of cultivation chambers in series with an enclosed cultivation chamber. [0169] FIG. 10 is a schematic diagram illustrating carbon capture and recycling process overview. [0170] FIG. 11 is a graph illustrating Photo-inhibition demonstrated via O2 production over a 24 hour period in which the left axis is O2 production in percent the base axis is time of day and the right axis is proton fluence (μmol/(m2*s) [0171] FIG. 12 is a schematic diagram illustrating a number of vertical growth columns [0172] FIG. 13 is a schematic diagram illustrating a plurality of cultivation chambers in series with an enclosed cultivation chamber as shown in FIG. 9 showing the control loops and inputs into the system in detail and [0173] FIG. 14 is a schematic diagram of a biological cultivation system using a number of different sized cultivation chambers. DETAILED DESCRIPTION OF THE EMBODIMENTS Example 1 [0174] A chamber for the cultivation of photosynthetic organisms was created using a bag culture system as shown in FIG. 1 . The cultivation chamber 1 includes a flexible bag ( 1 ) containing a culture medium for growing algae ( 2 ); gas outlet ( 3 ); fan ( 4 ); gas inlet ( 5 ); cultivation medium outlet ( 6 ); and cultivation medium inlet ( 7 ). [0175] The operation of bag cultivation chamber 10 is as follows: 1 A fan ( 4 ) inflates the empty cultivation chamber (without culture medium ( 2 )) to operational volume, with all excess pressure exiting through the gas outlet ( 3 ). The fan is continuously running so as to ensure the bag ( 1 ) does not deflate. 2 The empty cultivation chamber is inoculated with 10 000 l of microalgae culture (0.2% algae) produced in a separate photobioreactor and topped up with 10 000 l filtered and treated recycled saline waste water. 3 CO 2 is injected continuously during daylight hours through the gas inlet ( 5 ). The microalgae absorb the required quantities of CO 2 and the excess is released through the always open gas outlet ( 3 ). 4 An additional 20 000 l of recycled saline waste water is added, bringing the total capacity to 40 000 l of culture medium. 5 This process continues for another 24 hours until total harvesting capacity reaches 100 000 l. At this stage, the level of the culture medium ( 2 ) in the cultivation chamber is 60 cm. 6 After the algae have reached maximum harvest capacity (72 hours), 50 000 l is harvested from the cultivation medium outlet ( 6 ). 7 50 000 l of recycled saline waste water is returned to the cultivation chamber via the cultivation medium inlet ( 7 ), bringing the total culture medium volume back to 100 000 l. 8 The harvesting and return cycle repeats once every 24 hours, while maintaining continuous CO 2 injection during daylight hours. Example 2 [0184] The bag cultivation chamber described in Example 1 was modified as shown in FIG. 2 . In this embodiment, the cultivation chamber 20 includes a flexible bag ( 11 ) containing a culture medium for growing algae ( 12 ); gas outlet ( 13 ); gas bubbling tracks ( 14 ) with pinprick holes ( 15 ); gas inlets ( 16 ); cultivation medium outlet ( 17 ); cultivation medium inlet ( 18 ); draining outlet ( 19 ) and float valve ( 10 a ) to regulate ports ( 17 ), ( 18 ) and ( 19 ). [0185] The operation of bag cultivation chamber 2 is as follows: 1 Cultivation chamber 20 inoculation follows the same procedure as Example 1 steps 2, 4 and 5 to bring the harvesting capacity to 100 000 l within 72 hours. 2 CO 2 is pre-mixed with a high efficiency particulate air (HEPA) filtered air stream and fed through gas inlets ( 16 ) to gas bubbling tracks ( 14 ). These tracks are pinpricked ( 15 ) at suitable intervals to allow even air/CO 2 distribution along the length of the bag cultivation chamber. This bubbling operates continuously, with the CO 2 component reduced overnight. The air/CO 2 injection acts to slowly inflate the bag ( 11 ) and maintain circulation of the algae in the culture medium ( 12 ). Excess pressure is released through the one-way valve regulated gas outlet ( 13 ). This creates a closed loop system to minimise the contamination risk. 3 After the 72 hours of culturing the microalgae, 50 000 l is harvested from the ball-valve-regulated ( 10 a ) cultivation medium outlet ( 17 ), which is positioned at 30 cm in height. Once the cultivation medium reaches 30 cm, a signal is sent to the automation system that the cultivation chamber is at 50 000 l capacity. 4 50 000 l of treated recycled saline or freshwater waste water is returned to the cultivation chamber via the ball valve-regulated ( 10 a ) cultivation medium inlet ( 18 ), sending a back pressure signal to the automation system that the cultivation chamber is now at 100 000 l. 5 The ball valve-regulated ( 10 a ) draining outlet ( 19 ) allows the complete draining of cultivation chamber in case of contamination or for a regular cleaning routine. The remaining cultivation medium is either drained to the harvesting system for processing or, in the case of contamination, to the UV treatment system. Example 3 [0192] The bag cultivation chamber described in Example 1 was further modified as shown in FIG. 3 . The cultivation chamber 30 includes a flexible bag ( 21 ) containing a culture medium for growing algae ( 22 ); gas outlet ( 23 ); gas bubbling tracks ( 24 ) with pinprick holes ( 25 ); gas inlets ( 26 ); cultivation medium outlet ( 27 ); cultivation medium inlet ( 20 b ) with pressure sensor ( 18 ) and ball valve ( 20 a ). [0193] The operation of bag cultivation chamber 30 is as follows: 1 Cultivation chamber 30 inoculation follows the same procedure as Example 1 steps 2, 4 and 5 to bring the harvesting capacity to 100 000 l within 72 hours. 2 CO 2 is pre-mixed with a high efficiency particulate air (HEPA) filtered air stream and fed through gas inlets ( 26 ) to gas bubbling tracks ( 24 ). These tracks are pinpricked ( 25 ) at suitable intervals to allow even air/CO 2 distribution along the length of the cultivation chamber. This bubbling operates continuously, with the CO 2 component reduced overnight. The air/CO 2 injection acts to slowly inflate the bag ( 21 ) and maintain circulation of the algae in the culture medium ( 22 ). Excess pressure is released through the one-way valve regulated gas outlet ( 23 ). This creates a closed loop system to minimise the contamination risk. 3 After the 72 hours of culturing the microalgae, 50 000 l is harvested from the cultivation chamber through the ball valve-regulated harvesting outlet ( 27 ). The required volume is determined by measuring volume in reference to a pressure head sensor ( 28 ). 4 50 000 l of treated recycled saline or freshwater waste water is returned to the cultivation chamber via the ball valve-regulated ( 29 ) cultivation medium inlet ( 20 b ) with pressure head sensor ( 28 ), sending a back pressure signal to the automation system that the cultivation chamber is now at 100 000 l. [0199] Further detail (in top view) of a gas bubbling setup that may be included in the modified cultivation chamber is provided in FIG. 4 . This figure shows gas bubbling tracks ( 35 ) in the base of a bag cultivation chamber having a gas inlet ( 31 ) with compression fitting ( 32 ), a conduit ( 33 ) to transport the gas to restrictive flow orifices ( 34 ) and the end of each track ( 35 ) and pinprick holes ( 36 ) to allow the exit of gas. [0200] This figure shows six gas bubbling tracks ( 35 ) with pinprick holes ( 36 ) which are fed with gas introduced through the gas inlet ( 31 ) and compression fitting ( 32 ) via a gas conduit ( 33 ) and restrictive flow orifices ( 34 ) at the end of each track. The restrictive flow orifices serve to divide the gas flow evenly between the air distributor vanes. The flow rate of the gas through the gas inlet is approximately 100 kg/hr and through the restrictive flow orifice 17 kg/hr. Example 4 [0201] The growth of the microalga Nannochloropsis oculata was tested using the bag cultivation chamber described in Example 1. This culture bag was 10 m in length and 3 m in width and fitted with a six-bladed fan at one end to keep the bag inflated and drive evaporation. Along the top of the bag, four holes (13 cm diameter) allowed hot air and vapor to escape. This evaporation assisted in maintaining the algal culture at more stable temperatures. [0202] In this trial, both freshwater and filtered marine aquaculture waste (A3) water was added to the culture to account for salinity increases and evaporative loss of liquid. The bag cultivation chamber was filled to approximately 0.30 m in depth, resulting in a final culture volume of slightly less than 9 m 3 . The algae were cultivated in sea water than had been filtered through 20 μm, 5 μm and 1 μm filters. [0203] Aeration and CO 2 enrichment was provided through tubing designed for the gas diffusion via delivery into liquid media. This tubing had an outer diameter of 25 mm, an inner diameter of 10 mm and a porous wall of 7.5 mm thickness. [0204] The bag cultivation chamber system was inoculated with Nannochloropsis oculata with an apparently low cell concentration of 2.1×10 4 cells mL −1 and not filled up to full capacity volume. Already after 24 h, cell densities had increased dramatically, indicating time requirements for complete mixing of inoculate and culture medium (incomplete mixing affects correct determination of cell concentration), and the bag was filled up to its maximum depth on day 2. The growth of the culture up to the harvest of the algae on day 20 is shown in FIG. 5 . Nutrient Consumption [0205] There was a steady increase in nitrite from the day of inoculation (0.5 mg L −1 ) to day 8 (2.5 mg L −1 ) ( FIG. 6 A). After a few days at a steady concentration, nitrite peaked at 3.7 mg L −1 on day 13, and then was rapidly utilized. Within a few days, nitrite was depleted and remained so until the culture crashed. Nitrate was a high 90 mg L −1 at the beginning of the period, and was steadily being utilized ( FIG. 6 B). From day 13, nitrate concentration remained stable around 10 mg L −1 . There was an increase in phosphate the first few days (through addition of filtered A3 water to top the system up) ( FIG. 6 B). From day 3, phosphate was being noticeably assimilated and fluctuated between 2 mg L −1 and totally deplete. No nutrients were added to the bag system, however fresh filtered A3 water was regularly added along with freshwater to compensate for evaporation. The added A3 water accounts for the regular, small increases in nutrient concentrations. Physical and Chemical Parameters [0206] In the culture, pH quickly rose to over 9 in the first three days ( FIG. 7 ). After day 3, a CO 2 supply was connected and pH could now be regulated by adding CO 2 when a value above 8.4 was recorded. [0207] Photosynthetic activity was high in the bag in the beginning of the period, with rapid changes in pH due to uptake of CO 2 during photosynthesis, leading to large fluctuations in pH. [0208] Temperature fluctuated in diel rhythm, with the highest temperatures measured in the afternoon (4 pm) ( FIG. 7 B). Similar to the tank system, temperatures rarely rose above 30° C., and were quite stable. [0209] Conductivity in the bag fluctuated between 32 and 36 mS due to evaporation, and both freshwater and additional filtered A3 water was regularly added ( FIG. 7 C). [0210] The carbon capture and recycling process according to the present invention will be described with reference to FIGS. 8 , 9 and 10 . FIGS. 8 and 9 show an embodiment of a cultivation system in accordance with the invention. The system includes a plurality of cultivation chambers 100 . The cultivation chambers 100 are shown as arranged in parallel in four cultivation sections 101 , 102 , 103 , 104 which are also connected in parallel to a pumping station 105 . The pumping station 105 includes a harvest pump 106 and return pump 107 . [0211] Each cultivation section is provided with a valve manifold assembly 111 including metering 108 a and 108 b to monitor the rates of flow of CO 2 , nutrient and media (water) to and from each cultivation section of cultivation chambers 100 and a programmable logic controller (PLC) 109 to control the flow rates to optimize growth of the photosynthetic organisms in the cultivation chambers 100 . A balance tank 113 is also provided on the supply side to ensure that a head is maintained for pumping. The operation of each valve manifold assembly 111 form each cultivation section is controlled by a master controller 112 . [0212] The control unit 105 may include one or more of: (a) a mobile or fixed balance tank 113 and/or sampling point with a reservoir capacity of water growth medium used to produce algae. (b) process units, circulation, harvesting and make-up water pumps 106 , 107 . These pump from the control unit 112 to the cultivation chambers either directly via pipes or via a valve manifold assembly. 111 (c) a tank or reservoir volume 113 that may act as a dosing point for nutrients, chemicals and CO 2 , data collection point for instrumentation used for process collection and measurement. The tank or reservoir volume 113 may allow a period of darkness to allow the algae to have rest period (d) a discrete power supply interface for the above function requirements (e) a process controller device 109 ie, discrete 10 virtual PLC and conventional PLC as well as SCADA device type equipment [0218] In an alternative embodiment ( FIG. 13 ), the control unit may include one or more of (a) a fixed balance tank and/or sampling point with a reservoir capacity of water growth medium used to produce algae. This may be a fixed above ground 4-sided water tight structure 200 with bulkheads that will allow the secure mounting of valves, pumps and other ancillary equipment used to grow algae. This may be covered with a light impermeable cover to either block light from the algae in medium or with a light permeable cover to allow light to reach the algae depending upon process requirement. (b) process units, circulation, harvesting and make up water pumps 212 . This will pump from the rigid cultivation chamber 200 to the bulk cultivation chambers 200 either directly via pipes or via a valve manifold assembly. (c) a tank or reservoir volume 213 that will act as a dosing point for nutrients, chemicals and CO 2 , data collection point for instrumentation used for process collection and measurement. (d) a discrete power supply interface for the above function requirements (e) a process controller device ie, discrete IO virtual PLC and conventional PLC as well as SCADA device type equipment (f) an evaporative cooling assembly (not shown) mounted internally to cool an entire maniple (group) of parallel cultivation chambers e.g. via solar radiation will be routed through the rigid chamber and cooled via evaporation water fall and air movement. (g) a means of air movement e.g.; blower mounted to the bulkhead of the rigid chamber. (h) the rigid chamber 200 may also incorporate both water recirculation and/or air bubbling reticulation devices allowing both air and water to a) circulate algae for process flow to ensure homogeneous distribution of the algae throughout the growth system b) keep algae in suspension to promote homogeneous algae distribution through the growth medium water and prevent stratification of algae c) act as venturi delivery system for additional air or CO 2 [0230] The control unit may further include a drive controller(s) to control the pumping rates of the culture medium. Preferably the drive controller(s) are variable speed drive controllers (VSP). Variable speed drives to control pumps both AC and DC powered allow variable pumping rates of algae growth medium for use in process control. The pumping rates of water may be varied upon growth requirements or harvesting/make up Input/output (I/O) Variable Frequency Drives (VFD), Pulse width modulated (PWM) and/or Vector type pumping drive controllers. DC drive controllers can be either variable voltage control or with pulse width modulation. [0231] The above mentioned VSD based controller operates on variations of an AC input to DC bus to AC output. Permutations may include: (a) AC input to DC bus via rectifier of an inverter that is used for leveling voltage feeding an AC output—This will allow AC generation sources for renewable energy such as 3 phase wind turbines or conventional mains power to drive or power and control an AC powered electrical motor, pump, blower or frequency emitter. This can be used but not is limited to operate a pump, blower or lysing operation. (b) A direct DC input such as solar panels and/or DC wind turbines to the DC BUS of an inverter that will invert DC to AC to drive an AC powered electrical motor. This can be used but is not limited to operate a pump, electric blower, process controller or any other device associated with algae production/harvesting. (c) A combination of both AC and DC inputs jointly to function as above to drive an AC powered device such as a pump, power supply, process controller or algae lysing device that relies on either a source of renewable energy DC or conventional mains power (AC?). (d) A combination of (a), (b) and (c) I allowing an inverter based device to drive either a DC or AC PWM output for algae lysing (cracking). [0236] FIG. 10 , shows the process flow of production and harvesting of algae and other photosynthetic organisms. The Biological Algae Growth System (BAGS) 50 are initially filled with fresh/salt water 51 in line with nutrient dosing, from a dosing unit 52 . These bags are then inoculated from an existing source of algae at harvesting density. [0237] CO 2 /flue gas 53 to aid biomass growth and filtered air for circulation and dissolved O 2 off gassing was transferred to the BAGS during the algae's growth cycle. [0238] Once harvesting algae density is attained (up to 1.0 wt % but typically 0.2 to 0.7 wt %), the BAGS are harvested and transferred to the dewatering stage 54 . [0239] The dewatering stage transfers the centrate/filtrate water to a treatment plant prior to recycling the water back to the BAGS via nutrient dosing and water top-up. [0240] The algae concentrate from the dewatering stage proceeds to a thickening stage 56 to further concentrate the algae. [0241] This concentrate may then be transferred to lipid extraction 57 and product separation 58 to attain high quality algae oil 59 and meal 60 for further product treatment and distribution. Functional Requirements [0242] The key functional requirements for the CRS (computerised reticulation system are as follows: Provide sufficient flow rate to enable optimal growth rate of algae biomass To house the control systems and power source for all local valves, pumps, instruments, cooling systems and reticulation systems. Ensure efficient balance of flow during the algae recirculation phase of operation. Ensure continual pump prime is maintained for circulation and harvest phases. Integrated and controlled carbon dioxide (CO 2 ) injection manifold to ensure optimal growth of algae by preventing carbon limitation. Integrated gas escape mechanism whereby waste gas (e.g. dissolved O 2 ) can be exhausted from system. Ensure gas is discharged appropriately according to power station and DERM requirements. Inclusion of algae broth temperature control mechanism to maintain the algae within prescribed growth limits. Protection protocols and systems installed to ensure minimal algae contamination possible from other microorganisms. Integration with all in field instrumentation to gather relevant growth data. Designed sufficiently stable and robust to handle continual outdoor exposure. Minimise energy usage. Ease of maintenance, particularly ease of cleaning. Ease of connection and disconnection of skid and its individual plumbed and electrical components Algae Growth System Design [0257] A single cultivation section is illustrated in FIG. 9 consists of a manifold of three 50 m BAGS 100 and one 50 m TAGS. 100 The BAGS 100 are made from a translucent polypropylene, while the TAGS consist of a transparent Laserlite™ covered and lined above-ground pond. The BAGS are inflated by small electrical motor driven fans. Vent openings on the BAGS 100 and TAGS 100 a permit free release of excess gases and excess dissolved oxygen (O 2 ) produced during the photosynthetic growth phases of the algae. Process [0258] The initial water injection or water make up for the BAGS/TAGS, as well as the inoculation algae stream, will be transferred from elsewhere on site to the balance tank. [0259] Pump P 1 is used to pump from the balance tank 113 into the combined manifold and then along the length of the four growth vessels (via a perforated sparge bar inside the algae solution). [0260] Pump P 2 is then used to pump from the growth vessels back to the balance tank 113 . Circulation is maintained via the loop: VESSELS>P 2 >BALANCE TANK>P 1 >VESSELS. [0261] Filtered air is introduced during the circulation phase to remove dissolved O 2 produced during the growth phase. This could be into the buffer tank, directly into the growth systems or both. [0262] CO 2 is introduced during the circulation phase, directly into the liquid stream before it enters the vessels. This is modulated according to the photosynthetic requirements of the algae. [0263] Nutrients are also dosed into the balance tank during the circulation phase according to the photosynthetic requirements of the algae. [0264] When harvesting the algae the biomass is dewatered resulting in higher concentration of organisms per unit volume, pump P 3 transfers the algae solution from the balance tank to the dewatering system on site for product concentration. Interface [0265] The following connections interface with the CRS (controlled release system): Inputs [0000] Water/inoculation line for fresh/salt top-up water and inoculation from other algae growth systems. Harvest line from BAGS/TAGS to skid Filtered air @ 0.4 bar for dissolved O 2 off gassing. CO 2 @ 9 bar for algae growth. Control inputs from master PLC (programmable logic control). Power for skid equipment, associated valves and instrumentation and BAGS fans. Outputs [0000] Harvest line for harvest of algae biomass when at harvesting density. Return line from skid to BAGS/TAGS Instrumentation and pump and valve status outputs Display Facility Concept [0275] The multi-component growth system illustrated in FIG. 8 . Process [0276] The individual circulation process occurs as outlined above, only with a greater volume of BAGS. The CRS is intended to control up to eight BAGS in the display-scale growth system, with a master control system monitoring the outputs from each unit. All harvested algae and return water is transferred via the master system to distribute to the local CRS. System Data [0277] All system data is based on the research-scale algae growth system. Reticulation Growth System Specifications [0278] Specifications for the algae growth system: [0000] Design Parameter Value Comments BAGS length, m 50 BAGS width, m 3.4 BAGS depth, m Normal working depth 0.3 Design BAGS systems to allow trial Maximum working depth 0.6 operation up to 0.6 (optimal height) Inflated bag height 0.8-1.1 Number of BAGS in 4 manifold BAGS volume range, kL  50-100 For one BAGS (0.3-0.6 m depth) Total BAGS volume 200-400 For a manifold of four BAGS range, kL Broth salt content  0-50 High end during evaporation loss (ppt salt) Max. daily evaporation 5000 Utilising cooling fan loss, L Operational water 20-40 temperature (° C.) Turnover Rate [0279] A number of factors influence the required growth system turnover (one complete cycle of system) time. These include the circulation rate of the algae, the response time of the critical growth parameters and the photosynthetic cycle over the growth period. Below is a discussion of how these factors affect the turnover rate for sizing of the circulation pumps on the skid. Experimental Results to Date [0280] The Photo Bio Reactor (PBR) based on 10 metre BAGS has maintained stable algae growth at flow rates between 3-5 volume turnovers per hour. Algae Circulation Rate [0281] It is preferred to keep the algae circulating inside the BAGS at an approximate rate of 1 Hz (1 cycle per second). This permits the algae to receive a more even distribution of light, nutrients and CO 2 as well as ensuring the algae does not settle to the base of the growth system and develop bio fouling. [0282] Two methods of creating sufficient biomass circulation patterns are via air bubbling or high velocity fluid injection. Critical Growth Parameters [0000] Nutrient addition: there is a requirement to control the nutrient injection into the broth accurately as this has a significant effect on lipid production. Maintaining the nutrient feed on the edge of starvation has been suggested to increase the overall lipid content of the given species. Complete nutrient consumption may occur in as little as 12 hours, and algae may be starved for a period of approximately 1 to 5 hours before harvesting to promote lipid production. An estimated acceptable response time for nutrient control is 30-60 mins. (i.e. at least 1-2 volume turnovers per hour) CO 2 addition: CO 2 is added to the broth for two primary purposes: to act as a controlling mechanism for the pH level (to bring down a high pH add more CO 2 ) and to ensure that the algae are not carbon limited during the photosynthetic active growth period. It is important to monitor the pH and carbon regularly to ensure maximum cell reproduction and to minimise the harvesting period. An estimated acceptable response time is 15 mins. (i.e. at least 4 volume turnovers per hour). Dissolved O 2 reduction: an increase in fluid movement can aid in the reduction of dissolved O 2 by increasing the air to water surface contact area, which is essential to ensure that the algae does not experience oxygen super saturation (poisoning effect). An estimated acceptable flow rate is 1 volume turnover per hour. Photosynthetic Response [0287] The diurnal cycle (day/night) is an important control factor in the turnover rate calculations. During the night and period of low photosynthetic response (heavy clouds, shading etc) the following changes apply: CO 2 consumption drops to near zero Respirated O 2 output decreases Nutrient consumption decreases Growth rate slows (night) [0292] Therefore parameter response times and circulation rates become less critical and there is not the same turnover rate requirement during these periods. At night, the main variable becomes the risk of biofouling due to lack of circulation of the algae broth. This implies that the circulation pumps on the CRS will require either a large range of flow rates, or two separate pumps (one for high speed day cycle and one for low speed night cycle). [0293] The other component of the growth cycle that will affect the above changes is photo-limitation and photo-inhibition ( FIG. 11 ), which occurs during period of high fluence (light exposure). This is a photo-protective mechanism of all algae species (varies by species) that impairs the photo systems to protect the photosynthetic apparatus. Essentially it means that photosynthesis is also limited during periods of very high light intensity (i.e. during the middle of the day). This further supports the notion that a range or two separate circulation flows may be useful, to allow adequate control of critical parameters during periods of high photosynthetic activity while minimising energy consumption the remainder of the time. Circulation Flow Rate Summary [0294] [0000] Design Parameter Value Comments PBR trial, volume turnover per hour 3-5 Previous BAGs trials, volume turnover per 1-2 hour Algae circulation, volume turnover per hour [TBC] Nutrient addition, volume turnover per hour >1-2   CO 2 addition, volume turnover per hour >4 O 2 reduction, volume turnover per hour >1 Total BAGS volume, kL 200-400 For a manifold of four BAGS Flow rate at 0.3 m depth, kL/min: 1 volume turnover per hour 3.4 5 volume turnovers per hour 17 Flow rate at 0.6 m depth, kL/min: 1 volume turnover per hour 6.8 5 volume turnovers per hour 34 Harvesting Flow Rate [0295] The flow rate for the harvesting pump must also be considered. It has been proposed to harvest 25-50% of the BAGS volume every 24 or 48 hours. The time over which the desired BAGS volume must be harvested is approximately 8 hours; this is a trade-off between the harvesting system size required and the length of time an operator must be present on site. For BAGS at a depth of 0.3 m, to harvest 25% over 8 hours the required flow is 6.25 kL/hr; at 50% the required flow is 12.5 kL/hr. For BAGS at a depth of 0.6 m, to harvest 25% over 8 hours the required flow is 12.5 kL/hr; at 50% the required flow is 25 kL/hr. Head Requirements [0298] In order to circulate the algae, low head high flow pumps are required. [0299] Some approximate calculations were carried out on Pump 1 to determine rough pipe sizes and head requirements for the various flow rates: [0000] Flow rate Manifold size (mm) Sparge Bar size (mm) Head (m) 400 kL/hour 280 140 2.6 800 kL/hour 355 180 3.4 1600 kL/hour  500 250 3.1 Assumptions: minimum tank level of 0.6 m, PE piping, all BAGS operating at 0.6 m [0300] Note that the approximate pipe diameter for a flow of 1600 kL/hour (4 volume turnovers per hour) is almost half of the water depth in full BAGS and almost the entire depth in harvested BAGS. [0301] Similar calculations were carried out on Pump 2 . As an example, at 400 kL/hour with the same pipe sizing given above (280 mm manifold, 140 mm sparge bar) approximately 1.4 m head is required to transfer the algae from BAGS at 0.3 m depth to a tank with a top level of 0.3 m. Obviously as the height of the tank top level increases, the head requirements will increase accordingly. Care will need to be taken to ensure there is adequate suction head available for the pump. For gravity flow with these pipe sizes, the tank top level would have to be at least 1.4 m above the top water level of the BAGS. [0302] Care will also need to be taken in pump selection to ensure the algae are capable of handling the shear forces involved in pumping. Balance Tank System [0303] An internal balance tank on the CRS may be used: To maintain sufficient head for pump P 1 and balancing circulation flows between pumps P 1 and P 2 Point for nutrient monitoring and injection Point for instrumentation package to interface Harvesting point Potential for dissolved O 2 off gassing Sampling point for manual analysis [0310] Note that a mixing or circulation arrangement may be required to ensure there is no settling of algae. Valves will also need to be carefully considered, as there will be a requirement for two-way pressure adjustments while preventing contamination from entering the tank. Growth Parameters Nutrient Addition [0311] For the research plant, the required nutrients will be supplied in the form of pre-prepared and sterilised solutions—one for nitrate and the other for phosphate. [0312] Two separate dosing pump systems will be used, allowing the ratio to be readily adjusted. Dosing could be directly into the balance tank on the BAGS skid or in line with the fluid flow, with the dosing flow automatically proportioned based on broth flow rate and nutrient monitoring. [0313] The required nutrient concentrations are: [0000] Nutrient Design Point Allowable Range Nitrate 0-30 mg/L 0-100 mg/L Phosphate 0-10 mg/L  0-50 mg/L CO 2 and Air Injection [0314] As has been previously mentioned, CO 2 is added to the algae solution for two primary purposes: to ensure the algae are not carbon limited during the period of photosynthetic activity and to act as a controlling mechanism for the pH level. This may be supplied directly from a pressure vessel containing pure CO 2 , however this may also come from the flue gas and will thus be heavily diluted. [0315] Direct injection into the algae solution circulation flow via a venturi arrangement may be the most effective method for increasing dissolved CO 2 . An alternative method is to bubble the CO 2 through the solution in combination with the air bubbling described below. [0316] As has also been previously mentioned, excess dissolved O 2 may be removed from the water as this can poison the algae. One method to assist with this is simply fluid circulation, which increases the air to water surface contact area and thus allows more O 2 to come out of solution. [0317] A second method to assist with dissolved O 2 reduction is bubbling air through the algae solution from the base of the BAGS. Provided that enough dissolved CO 2 remains in the solution (CO 2 can be readily displaced by oxygen and nitrogen if air is bubbled through water), air bubbling through the BAGS may help to draw dissolved oxygen out of the solution. Note that the transfer of molecules from a gaseous form to a dissolved form is dependent on solubility and relative concentration levels; there is an equilibrium condition between the gaseous and dissolved forms. For example, nitrogen gas molecules can readily displace CO 2 gas molecules. To maintain equilibrium this causes more dissolved CO 2 to come out of solution. [0318] Finally it has also been previously mentioned that the algae should be kept circulating inside the solution to receive a more even distribution of light, nutrients and CO 2 as well as ensuring the algae do not settle out of suspension. A second advantage of air bubbling (aside from dissolved CO 2 reduction) is that it may be used to assist in this internal circulation of algae within the BAGS. Temperature Control [0319] A temperature control system may optionally be included. System Management Operation [0320] Operational specifications: 24 hour continuous pump operation Control Requirements [0322] Valve and pump requirements and in field solenoid valves [0323] The list of associated instrumentation to interface with CRS PLC: [0000] Sensor Desired Spec. Dependant Control Data Units Range Range Purpose Relationships Mechanism Physiochemical Data Dissolved O 2 % 80-130  0-300 Avoid oxygen Fluid super saturation recirculation Bubbling Dissolved CO 2 g/L 0.05 g/L Control pH pH Throttle CO 2 Photosynthesis Dissolved O 2 injector (photosynthesis dependant) Free CO 2 μL/L Monitor CO 2 Dissolved O 2 Throttle CO 2 uptake by algae (photosynthesis injector dependant) pH Value 7.8-8.2  3-12 Broth acidity Dissolved CO 2 CO 2 injection (SW) detection 6.4-7.4  (freshwater) Temperature - ° C. 25-30  0-50 Maintain ideal Cooling Liquid growth temps system Temperature - ° C. 25-30  0-60 Maintain ideal Cooling Air growth temps system Conductivity μS/cm   5-7 × 10 4     0-10 × 10 4 Monitor salinity Temperature Dose in Include of water additional fresh/ freshwater salt water range Weather Data Temp Humidity Light levels Wind speed Rain gauge Nutrient Data Nitrate mg/L 0-40  0-100 Consumption All Dosing pump Top ups Nitrite mg/L 0-30  0-100 Consumption All Dosing pump Top ups Phosphate mg/L 0-10 0-50 Consumption All Dosing pump Top ups Biomass Detection Turbidity % trans at  30-80%      0-100% Determine All 750 nm rel. to algae cell count salt/fresh- water water medium photosynthetic μmol/(m 2 *s) Determine photon flux algae cell count density (higher precision) CO 2 uptake Vertical Growth Column [0324] FIG. 12 illustrates an embodiment of an array of vertical growth columns 60 used in conjunction with the substantial horizontal cultivation chamber system of the present invention. Each column comprises a substantially cylindrical outer conduit 61 and a substantially cylindrical inner conduit 62 arranged vertically. The inner and outer conduit are fluidly communicating to enable growth media and algae which make up the algal slurry to circulate between. The growth columns 60 are provided with fluid inlets 63 and fluid outlets 64 for the introduction of growth media and an inoculate of algae and the removal of algal slurry. The columns 60 are also provided with gas inlets 65 for the introduction of CO 2 and air and gas outlets for the removal of gas. The gas outlets are provided with CO 2 sensors to monitor the CO 2 content on the outgoing gas. [0325] A pump 66 is provided to circulate the fluid to the columns. Once in the columns, the inflow of gas into the centre of the growth column causes the algal slurry to rise up to the top of the inner conduit before passing to the outer conduit where it descends the column. An alternative arrangement may be to add the gas to the outer conduit and have the algal slurry descend in the inner conduit. The choice of arrangement will depend on the growth rates of the algae, the density of the algae during circulation and the light transmissivity of the algal slurry at different stages of circulation. Once the algal slurry has reached a suitable density then it is removed through outlets 67 and either used as a product or used as an inoculate in the cultivation chambers of the growth system. [0326] While the growth columns are shown as connected in parallel, the columns can be connected in series and optionally used as a stand alone growth system if the resulting growth rates in the columns are sufficiently high and sufficient product can be grow for the purposes required. The applicant has found that algal densities of up to 30-75 grams DW per square meter of media can be sustained in the vertical growth columns compared to approximately 20-35 grams DW per square meter in the cultivation chambers discussed earlier. [0327] While the growing of algae is well known, one of the difficulties in the industry is growing commercially useful amounts of algal biomass in a commercial time period. As the algal slurry increases in density, light transmissivity drops considerably with distance from the surface of the media. Thus for larger scale production, the depth of algal slurry through which light must travel seriously affects the growth rate of algae with algae further below the surface having a much slower growth rate than algae near the surface. Therefore to maximize grow, the algae must not be more than about 30 cm from the surface of the media. FIG. 14 shows a combined cultivation system used to produce algae at a large volume in a commercial time period. In this embodiment, the volume of each cultivation chamber is increased in each stage. [0328] In the first stage, CO 2 containing gas 69 mixed with aqueous nutrient media in a mixing tank 70 or like device is supplied to vertical growth columns 60 to initially grow the algae to a sufficient concentration to be used as a feed to larger volume cultivation chambers. This ensures that sufficient algae culture is introduced into the small cultivation chambers 100 for sufficient biomass to be grown in an commercially acceptable time period. Cultivation chambers 100 are typically 10 m in length and of a TAG construction described earlier. Cultivation chambers 100 are sized and controlled so that the residence time in the small cultivation chambers 100 produces sufficient biomass to be used as a feed for the large cultivation chambers 200 , 200 a . The sizing and control will depend on the levels of sunlight expected and actually received at the location of the plant, the acceptable residence time in the chambers, typically 24 hours and the growth rate of the culture. [0329] The algal slurry then passes to cultivation chamber 200 and then circulated through cultivation chambers 200 a to maintain exposure of a sufficient volume of media and algae to light to enable photosynthesis to continue at an acceptable rate. These cultivation chambers are preferably 50 m in length. Once the algal slurry has reached an acceptable density, it then passes to a harvest system 71 . [0330] It would be appreciated by those skilled in the art that the sizing of the cultivation chambers may vary depending on the available footprint of land available. However in accordance with this embodiment, the sizing of the cultivation chambers is progressively larger than the chambers in the previous section. [0331] It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

A biological cultivation system for the culture of photosynthetic organisms including at least one cultivation chamber permitting exposure of the culture medium to natural and/or artificial light and including; a light transmissive wall or walls defining a gas space; and a culture medium containment area below the gas space; one or more fluid inlets positioned within the culture medium containment area; and one or more gas outlets in communication with the gas space; a control unit operatively connected to a gas flow control device, the gas flow control device controlling the flow of gas in through the fluid inlets and out through the fluid outlets to control the conditions within the cultivation chamber.

TECHNICAL FIELD The present invention relates to shift mechanisms for manual transmissions in motor vehicles. More particularly, this invention relates to shift mechanisms with a shift shaft largely internal to a transmission housing for making gear range selections. Axial displacement of the shift shaft is used to select the desired gear range. Rotary displacement of the shift shaft is used to engage the desired gear. A select lever external to the transmission housing is used to axially displace the shift shaft. A shift lever, also external to the transmission housing, is used to rotatively displace the shift shaft. BACKGROUND OF THE INVENTION Conventional shift mechanisms for manual transmissions permit shifting from second gear to first gear when it is desired to shift from second gear to third gear. Synchronizers within the transmission can provide some resistance to downshifting, but that resistance can be overcome by the vehicle operator. SUMMARY OF THE INVENTION The present invention blocks a shift from second gear to first gear when the last preceding shift is a first gear to second gear shift. The transmission can be shifted into any gear except first. No other shift sequence is restricted. It is an object of this invention to inhibit shifting to first gear after a first gear to second gear shift. It is also an object of this invention to provide a device which restricts shifting to first gear after a first gear to second gear shift. It is further an object of this invention to provide a mechanism for a transmission having a shift lever, a select lever rotatively mounted to a transmission housing, and a shift shaft which blocks shifting from second gear into first gear after a first gear to second gear shift. These and other objects and advantages will be more apparent from the following description and drawings. DESCRIPTION OF THE DRAWINGS FIGS. 1-4 show the parts of the shift control attaching to the shift shaft from the distal end of the shift shaft. Each figure shows the parts in different relative positions which correspond to particular gear positions. FIG. 1 shows the shift lever in the neutral position and the select lever in the 1-2 gear range position with the shift lever disengaged from the shift lever cam. FIG. 2 shows the shift lever in the first gear position and the select lever in the 1-2 gear range position after a neutral to first gear shift. FIG. 3 shows the shift lever in the neutral position and the select lever in the 1-2 gear range position and the shift lever in Neutral after being shifted from first gear to neutral. FIG. 4 shows the shift lever in second gear after being shifted from first to neutral to second gear while maintaining the select lever in the 1-2 gear range position. FIG. 5 shows a side view of the shift control in the direction of arrows 5 of FIG. 3. FIG. 6 shows a sectional view of the shift control in the direction of arrows 6 of FIG. 3. DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1-6 all show an inhibitor 10 for a manual transmission shift control 12, located on the exterior of a transmission housing 14. The transmission has a plurality of drive gears, including but not limited to a first gear and a second gear as well as neutral where no drive gears are engaged. FIGS. 1-4 show the relative positions of the elements of the inhibitor 10 as the transmission is shifted from neutral to first gear and then from first gear to second gear. FIG. 5 highlights the rotatable operation of a select lever 16, showing the lever in a 1-2 gear range position 18 and a phantom outline 17 of the select lever 16 in a 3-4 gear range position 19. FIG. 6 shows a sectional view of the inhibitor 10 with the select lever 16 in the 1-2 gear range position 18 and a shift lever 20 in the neutral position 21. The sequence of shifting from neutral to first to second gear begins in FIG. 1 with the shift 20 lever in the neutral position 21 and the select lever 16 in the 1-2 gear range position 18. The inhibitor 10 does not restrict the positioning of the shift lever 20 here. This orientation of the elements occurs after the select lever 16 has been moved into the 1-2 gear range position 18 from another gear range position, such as the 3-4 gear range position 19. In FIG. 2 the shift lever 20 has been moved to the first gear position 22. In FIG. 3, the shift lever has been moved to the neutral position 21 on its way into the second gear position 23 shown in FIG. 4. When the shift lever is moved from the first gear position 22 to the neutral position 21, the shift lever 20 is linked to the select lever 16, thereby inhibiting movement of the shift lever 20 back toward the first gear position 22. FIG. 4 shows the shift lever 20 after it has been moved to the second gear position 23. Even when the shift lever 20 is linked to the select lever 16, there is no restriction in moving the shift lever 20 between the second gear position 23 and neutral. Rotating the shift lever 20 from the second gear position 23 to the neutral position 21 causes the relative orientation of the elements in FIG. 3 to be duplicated. The inhibitor 10 blocks any further movement of the shift lever 20 toward the first gear position 22. To shift into first gear, the select lever 16 must first be moved out of the 1-2 gear range position 18 to another gear range position such as the 3-4 gear range position 19 and then back into the 1-2 gear range position, returning the components to the orientation seen in FIG. 1. FIG. 6 shows a sectional side view of the inhibitor 10 and a shift shaft 24 interfacing with one type of gear selection/engagement means 26. The gear selection/engagement means 26 shown is similar to that shown in U.S. Pat. No. 4,174,644 to Nagy et al. on Nov. 20, 1979 and assigned to the assignee of this invention. The gear selection/engagement 26 means includes the shift shaft 24 and a shifter paddle 25 and gear engagement means 28, 30, and 32. The gear selection/engagement means 26 is used to select a desired gear range 34, 36, or 38 and to engage a desired gear (not shown) within the transmission housing. The gear ranges 34, 36, and 38 are the axial positions of the shift shaft 24 which permit engagement of a selected gear engagement means 28, 30, 32. For this embodiment, there is a 1-2 gear range 34, a 3-4 gear range 36, and a 5-R gear range 38. Gear range 34, 36, 38 selection is accomplished by axial positioning of the shift shaft 24 along a longitudinal axis 40 of the shift shaft 24. Engagement of gears (not shown) within the transmission housing 14 is accomplished by rotating the shift shaft 24 about the longitudinal axis 40 to displace the selected gear engagement means 28, 30, 32. The shift shaft 24 has a proximal end 42 which remains inside the transmission housing 14 and a distal end 44 which remains outside the housing 14. The transmission housing 14 rotatably supports the shift shaft 24, allowing the shift shaft 24 to both rotate and axially translate relative to the transmission housing 14. Each of the gear engagement means 28, 30, and 32 have a shift fork (not shown) and a pair of lugs 46, 48 and 50. The gap (not shown) between the lugs is a shift gate. The gear engagement means 28, 30, and 32 are positioned so that their respective lugs 46, 48, and 50 are located in close proximity to one another as seen in FIG. 6. The gear selection/engagement means 26 shown in FIG. 6 has the 1-2 shift gate lugs 46 on the bottom, the 3-4 shift gate lugs 48 in the middle, and the 5-R shift gate lugs 50 on the top. Only one of each pair of lugs 46, 48, and 50 for each gear engagement means 28, 30, and 32 are shown in the sectional view of FIG. 6 to illustrate the relationship of the lugs 46, 48, and 50 to the shifter paddle 25. The shifter paddle 25 is rotatively and axially fixed to the shift shaft 24. Each pair of lugs 46, 48, and 50 of the gear engagement means 28, 30, and 32 is disposed for engagement with the shifter paddle 25. Selection of the appropriate gear engagement means 28, 30, and 32 is made by moving the shift paddle 25 to the shift gate corresponding to the desired gear range 34, 36, 38. The shift paddle 25 is moved to the desired shift gate by rotating the select lever 16 to axially displace the shift shaft 24. Movement of the shift shaft 24 between gear ranges 34, 36, 38 can only occur with the shift lever 20 in the neutral position 21 where none of the gears are engaged. The neutral position 21 of the shift lever 20 is independent of the axial position of the shift lever 20 and the shift shaft 24. The neutral position 21 of the shift lever 20 and shift shaft 24 is their rotative position approximately midway between the first gear shift lever 22 position and the second gear shift lever position 23. Rotary displacement of the shift shaft 24 causes the shifter paddle 25 to displace the lug 46, 48, 50 contacted, thereby displacing the corresponding gear engagement means 28, 30, 32 and shifter fork (not shown), moving a corresponding gear (not shown) or sleeve (not shown) in the same direction. The shift lever 20 is rotatively mounted to the shift shaft 24, near the distal end 44 of the shift shaft 24. The shift lever 20 has a ball stud 54 mounted to it serving as means for connecting the lever 20 to a transmission shifter (not shown). A suitable shifter and connecting cables are shown in U.S. Pat. No. 4,143,560 issued Mar. 13, 1979 to Kinkade et al. and assigned to the assignee of this invention. A transmission shift shaft collar 56 is fixed to the transmission shift shaft 24 intermediate between the shift lever 20 and the transmission housing 14. The shift shaft collar 56 is annular in shape. As shown in FIG. 6, the collar 56 has an inside surface 58, an outside surface 60, a top side 62 and a bottom side 64. The inside surface 58 facilitates placement of the shift shaft collar 56 over the shift shaft 24 and fixing to the shift shaft 24. The collar 56 is fixed to the shift shaft 24 by a shear pin 66 which passes through aligned apertures 68 in both the collar 56 and the shift shaft 24. The pin 66 is retained by an interference with the aperture 68 in the shift shaft 24. The outside surface 60 is largely defined by a diameter concentric with the inside surface 58, but has an engagement channel 70 traversing the outside surface 60 equidistant between the top side 62 and the bottom side 64 for slidable engagement with a stub pin 72 of the select lever 16. There is also an engagement groove 74 in the outside surface 60 of the collar 56, from the top side 62 to the bottom side 64, located approximately opposite the engagement channel 70, for slidable engagement with a shift lever detent plunger housing 76. The shift shaft collar 56 also has an aperture 78 in the top side 62 for retaining a lower end 82 of a shift lever cam spring 80. The select lever 16 is rotatively mounted to the transmission housing 14. The stub pin 72 of the select lever 16 slidably engages the engagement channel 70 of the transmission shift shaft collar 56. When the select lever 16 is rotated, the stub pin 72 is arcuately displaced about a center of rotation 84 of the select lever 16. The stub pin 72 slidably translates across the engagement channel 70 of the collar 56 while slidably displacing the collar 56, and thereby the shift shaft 24, along the longitudinal axis 40 of the shift shaft 24. The select lever 16 also has a ball stud 86 as means for connecting the lever 16 to the transmission shifter (not shown). The select lever 16 also has a select lever detent plunger housing 88 formed integral with the select lever 16. The shift lever detent plunger housing 76 is fixed to the shift lever 20. The detent plunger housing 76 slidably engages the engagement groove 74 of the transmission shift shaft collar 56 parallel to the longitudinal axis 40 of the shift shaft 24. The detent plunger housing 76 imparts rotary motion to the shift shaft 24 with rotary movement of the shift lever 20. The housing 76 is tubular in shape with an inside diameter 90 and an outside diameter 92 as shown in FIG. 6. The housing 76 has an upper end 94 and a lower end 96. The upper end 94 of the detent plunger housing 76 is fixed to the shift lever 20. Disposition of a top detent plunger 98 and a bottom detent plunger 100 within the shift lever detent plunger housing 76 is accommodated by the inside diameter 90 of the detent plunger housing 76. The upper end 94 of the housing 76 is closed except for an orifice 102 to accommodate the passage of a nub 104 of the top detent plunger 98 through the upper end 94. The lower end 96 is open, accommodating installation of the detent plungers 98 and 100. The lower end 96 of the select lever detent plunger housing 88 has a slot 106 on the inside diameter 90 to accommodate a snap ring type retainer 108 for the detent plungers. The bottom detent plunger 100 is slidably disposed within the shift lever detent plunger housing 76. The bottom detent plunger 100 is tubular in shape, with an inside diameter 110 and an outside diameter 112. The bottom detent plunger 100 is open on an upper end 114 and closed on a lower end 116. The bottom detent plunger 100 also has a nub 118 on the lower end 116 which impinges against the select lever bracket 120 when the select lever 16 is placed in the 1-2 gear range position 18. The top detent plunger 98 is slidably disposed within the bottom detent plunger 100. The top detent plunger 98 is cylindrical in shape with an outside diameter 122 less than the inside diameter 110 of the bottom detent plunger 100. The top detent plunger nub 104 protrudes from the upper end 94 of the shift lever detent plunger housing 76 for engagement with an arcuate slot 124 in a bottom side 126 of a shift lever cam 128. A top detent plunger spring 130 is functionally interposed between the top detent plunger 98 and the bottom detent plunger 100 to sustain compressive loads between the plungers 98 and 100. The top detent plunger spring 130 is disposed within the inside diameter 110 of the bottom detent plunger 100. A bottom detent plunger spring 131 is functionally interposed between the shift lever detent plunger housing 76 and the bottom detent plunger 100 to sustain compressive loads between the plunger housing 76 and the bottom detent plunger 100. The spring 131 is disposed within the inside diameter 90 of the shift lever detent plunger housing 76. A bushing 132 retains and provides a centering pilot 134 for the shift lever cam 128. The bushing 132 is fixed axially and rotatively to the distal end 44 of the shift shaft 24. The bushing 132 is selectively removable from the shift shaft 24. A cam pin 136 is fixedly inserted in an orifice 138 in the bottom side 126 of the cam 128 as shown in FIG. 5. When the top detent plunger 98 of the shift lever 20 is disengaged from the cam 128, the cam 128 is positioned by an upper end 140 of the shift lever cam spring 80 pressing the cam pin 136 against the shift lever 20. A select lever detent plunger 142 is disposed within the select lever detent plunger housing 88. The select lever detent plunger 142 and the detent plunger housing 88 together engage a cam detent surface 144 of the shift lever cam 128 when the shift lever 20 has been in the first gear position 22 while the select lever 16 has been in the 1-2 gear range position 18. The shift lever cam spring 80 provides a torsional spring load to the cam 128 through the cam pin 136. The lower end 82 of the shift lever cam spring 80 is parallel to the longitudinal axis 40 of the shift shaft 24 and is inserted into the aperture 78 in the top side 62 of the shift shaft collar 56. The upper end 140 of the shift lever cam spring 80 extends out away from the shift shaft axis 40 in a plane perpendicular to the axis 40 for rotatably engaging the cam pin 136. The relationship between the cam 128 and the select lever detent plunger 142 can be seen in illustrations 1-5. They show how when the select lever 16 is in the 1-2 gear range position 18, the detent plunger 142 engages the cam 128. The shift lever cam 128 is mounted on the shift shaft 24 distal of the shift lever 20 and rotatively pilots on the bushing 132. The shift lever cam 128 is annular in shape with a central opening 148 of a constant diameter, providing a clearance fit to the bushing pilot 134. The cam 128 is rotatable about the longitudinal axis 40 of the shift shaft 24. The cam 128 has an outer wall 150 with the cam detent surface 144. The cam 128 also has an orifice 138 in the bottom side of the cam accommodating the fixed insertion of the cam pin 136. The arcuate slot 124 in the bottom side 126 of the cam 128 accommodates engagement with the nub 104 of the top detent plunger 98. This invention and the interrelationship of the parts can be more clearly understood by observing the sequence of operations of the device. On a shift into first gear from any other gear, except immediately following a 1-2 shift, the operation of the shift control 12 is much the same as with any conventional shift control. When, with the shift lever 20 in the neutral position 21, the select lever 16 is moved into the 1-2 gear range position 18 from another gear range position such as the 3-4 gear range position 19, the select lever detent plunger 142 impinges on the outer wall surface 150 of the cam as seen in FIG. 1. With the select lever 16 in the 1-2 gear range position 18, and the shift lever 20 in the neutral position 21, the cam 128 is not yet linked or engaged with the shift lever 20 by the top detent plunger nub 104. When the select lever 16 moves into the 1-2 gear range position 18, the bottom detent plunger 100 in the shift lever detent plunger housing 76 is pressed upward by contact with the select lever mounting bracket 120. The top detent plunger nub 104 is pressed upward against the bottom side 126 of the cam 128. The cam 128 is rotatively positioned relative to the shift lever 20 by contact of the upper end 140 of the shift lever cam spring 80 with the cam pin 136. The cam spring 80, when viewed from the distal end 44 of the transmission shift shaft 24, maintains a clockwise torque against the cam pin 136. The upper end 140 of the spring 88 is indexed counter clockwise relative to the bottom end of the spring 82 which in inserted in the top side 62 of the transmission shift shaft collar 56. The cam pin 136, and therefore the cam 128, are held rotatively fixed relative to the shift lever 20 by the clockwise torque provided by the spring 80. The shift lever 20 is rotated to the first gear position 22 causing the shifter paddle 25 to displace the lugs 46 on the gear engagement means 28, thereby displacing the gear engagement means 28, engaging first gear. As the shift lever 20 is moved counter clockwise into the first gear position 22, the cam 128 rotates with the shift lever 20 because of the contact between the cam pin 136 and the shift lever 20. As the shift lever 20 enters the first gear position 22, the select lever detent plunger 142 engages the detent surface 144 of the cam 128. When the shift lever 20 is in the first gear position 22, the cam 128 is located such that the select lever detent plunger 142 impinges on the cam detent surface 144. When engaged by the select lever detent plunger 142 and the detent plunger housing 88, the cam 128 is blocked from rotating in a counter clockwise direction and is restricted from moving in the clockwise direction by the select lever detent plunger 142. The clockwise restriction provided by the select lever detent plunger 142 impinging on the cam detent surface must be sufficient to prevail against a combination of both the torsional spring load of the shift lever cam spring 80 against the cam pin 136 and a frictional drag load on the cam 128 from the nub 104 of the top detent plunger 98 pressing against the bottom side 126 of the cam 128, so that the cam 128 will not be displaced in the clockwise direction as the shift lever 20 is moved from the first gear position 22 toward second gear. When the shift lever 20 reaches the neutral gear position as it is moved from the first gear position 22 to the second gear position as shown in FIG. 3, FIG. 5, and FIG. 6, the top detent plunger 98 is aligned with the counterclockwise end of the arcuate slot 124 in the bottom side 126 of the cam 128, allowing the top detent plunger nub 104 to travel up into the arcuate slot 124, engaging the shift lever 20 with the cam 128. As the shift lever 20 is moved into the second gear position it encounters no resistance from the inhibitor. The nub 104 travels along the arcuate slot 124 and the cam 128 continues to be held rotatively fixed by the select lever detent plunger 142. FIG. 4 shows the shift inhibitor 10, the select lever 16, and the shift lever 20 in their second gear positions. When the shift lever 20 is moved from second gear position back toward the first gear position 22, the top detent plunger nub 104 moves with the shift lever 20, traveling within the arcuate slot 124 in the bottom side 126 of the cam 128. The cam 128 continues to be rotatively engaged with the select lever 16 with the select lever detent plunger housing 88 blocking displacement of the cam 128 in the counter clockwise direction. The travel of the shift lever 20 is blocked at the neutral gear position by the nub 104 of the top detent plunger 98 reaching the counterclockwise end of the arcuate slot 124. The shift lever 20 is restrained from moving back into the first gear position 22. The orientation of the elements is the same as that shown in FIG. 3, FIG. 5, and FIG. 6. To release the inhibitor 10, allowing shifting into first gear, the select lever 16 must be rotated from the 1-2 gear range position 18 to the 3-4 gear range position 19 or the 5-R gear range position (not shown), thereby releasing the cam 128. When the select lever is moved from the 1-2 gear range position 18 to another gear range position, two things happen simultaneously to release the cam 128: first, the shift shaft 24 moves up as the select lever 16 is rotated, moving the shift lever 20 away from the transmission housing 14 and allowing the top detent plunger 98 to recede into the shift lever detent plunger housing 76 thereby disengaging the cam 128 from the shift lever 16, and second, the select lever detent plunger housing 88 allowing the cam 128 to once again freely rotate relative to the transmission housing 14. Once the cam 128 is fully released, the shift lever cam spring 80 again pushes the cam pin 136 against the shift lever 20, the same relative orientation of parts which this description began with, as seen in FIG. 1.

An inhibitor for a manual transmission shift control which aids in preventing unintended downshifts into first gear. The inhibitor blocks shifting from second gear to first gear following a first gear to second gear shift. No other shift sequence is affected.

[0001] This application is a National Stage completion of PCT/DE2009/050042 filed Aug. 11, 2009, which claims priority from German patent application serial no. 10 2008 041 374.7 filed Aug. 20, 2008. FIELD OF THE INVENTION [0002] The invention relates to an operating device for a gear shifting transmission, e.g. for a manual or automatic transmission having shift-by-wire actuation. BACKGROUND OF THE INVENTION [0003] Gear shifting transmissions of motor vehicles are generally shifted or controlled by means of an operating device disposed within reach of the driver. Actuating elements such as shift levers or selector levers are used regularly for this purpose, and are located, for example between the front seats of the motor vehicle or in other regions of the cockpit. [0004] In the case of mechanical transmission control or mechanical coupling between the selector lever and the gear shifting transmission—using a cable or linkage for example, the selector lever position always coincides with the actual transmission state due to the mechanical coupling. As a result, the driver can deduce, on the basis of the particular selector lever position, the current gear state of the transmission, and, then he can feel confident that the lever position coincides with the actual gear state of the transmission. [0005] However, when gear shifting transmissions are actuated electrically or using shift-by-wire, the actuating lever in the passenger compartment and the motor vehicle transmission in the engine compartment are no longer mechanically coupled in this manner. Instead, in the case of “shift-by-wire” transmissions, the shift commands are transmitted from the operating device to the motor vehicle transmission using electrical or electronic signals, and the shift commands are then implemented in the transmission using electrohydraulics, for example. Due to the absence of a mechanical connection between the transmission actuator system and the actuating lever, the transmission state, any shift interlocks, or impermissible shift commands can no longer impact the state of the actuating lever directly and noticeably for the driver. [0006] In by-wire actuated gear shifting transmissions, however, the absence of a mechanical connection between the transmission actuator system and the selector lever can, under certain basic conditions or in the case of an error, also lead to the selector lever position no longer coinciding with the gear state of the transmission. [0007] For example, modern automatic transmissions generally include a so-called “Auto-P” function, for example, that ensures that when the driver leaves the vehicle, the parking lock may possibly be engaged automatically in the transmission, for instance to prevent the unattended vehicle from rolling away if the driver failed to engage the parking lock before leaving the vehicle. In other words, the Auto-P function, which particularly can be automatically activated, when the ignition key is removed or the driver leaves the vehicle, ensures that the parking lock is automatically engaged in the transmission, regardless of the gear state that was actually selected using the selector lever. Thus, the parking lock would also be engaged automatically by the Auto-P function of the transmission or the vehicle if the driver had left the selector lever e.g. in the neutral position, in a tip gate that may be present, or in one of the gear selection positions. [0008] In this case however, the selector lever position does not coincide with the actual gear state of the transmission. When the driver returns to the vehicle or at the next attempt to start the vehicle, the position of the selector lever would therefore provide the driver visually and haptically with initially incorrect information. On the basis of his perception of the selector lever position, the driver would have to assume that the transmission is engaged in a neutral position, in the tip mode or in a gear selection position, although the transmission is actually engaged in the parking lock. This discrepancy between the selector lever position and transmission state could therefore lead to undesired operating errors or incorrect conclusions by the driver. [0009] The applicant's document, DE 10 2007 015 262 A1, discloses an operating device for a motor vehicle transmission having a device for selector lever return, which has an actuating device having a gear motor, with which the selector lever can automatically be returned from the manual shift gate (tip gate) into the automatic gate, or the selector lever can automatically be returned into the park lock position, for example. This known operating device is, however, associated with a certain design complexity in order to implement the desired actuating mobility of the selector lever, with the corresponding consequence of construction space and costs. It must also be expected that the electromotive drive and the reduction gear that are present there can generate disruptive noises. [0010] The same applies for the gear shift device for an automatic transmission known from DE 100 05 328 A1. In this gear shift device, a detent element connected to a selector lever is simultaneously in engagement with a notched contour and a ramp that is adjustable by a motor. By means of the ramp, the detent element can be brought out of engagement with the notched contour, and subsequently due to the incline of the ramp—together with the selector lever—can be automatically returned into a specific detent position. The motor or hydraulic drive of the ramp in this known device is, however, also relatively complex and requires considerable construction space. In the case of a drive using an electric gear motor noise problems are also to be expected. SUMMARY OF THE INVENTION [0011] Proceeding from this background, the problem addressed by the present invention is to create an operating device for a gear shifting transmission, with which the stated disadvantages found in the prior art can be overcome. The purpose of the invention is to reliably ensure that the selector lever position always reflects the actual gear state of the transmission, even with shift-by-wire-controlled gear shifting transmissions, for example in the case of the P-position, whereby reliable visual and tactile feedback about the actual gear state of the transmission can be realized. The invention is to prevent particularly that the selector lever, in the case of an automatically engaged park lock (“Auto-P”), remains misleadingly in the last engaged shift position. In contrast to the solutions known from the prior art, this functionality is to be implemented, however, with low design complexity, minimal construction space and without generating disruptive noises. [0012] In an initially known manner, the operating device according to the present invention comprises a housing base and a selector lever having a spring loaded detent element. The selector lever is movable back and forth between at least two detent positions or shift gates. Also in a known manner, the operating device further comprises a detent mechanism for locking the selector lever in the individual detent positions, wherein the detent mechanism has a notched contour for locking the selector lever and a bevel contour—having a corresponding incline with respect to the detent element—for automatically returning the selector lever into the first detent position. The detent element of the selector lever can be substantially simultaneously brought to overlap, or into engagement, with the notched contour and also with the bevel contour, and the notched contour and the bevel contour can be moved by actuation relative to each other in the direction of the selector lever detent element. [0013] According to the invention, the operating device is distinguished, however, in that the bevel contour is connected substantially rigidly to the housing base, whereas the notched contour can be moved back and forth relative to the housing base between a first position near the detent element and a second position away from the detent element. The notched contour is spring-loaded in the direction of the detent element of the selector lever, and in its first position overlaps the bevel contour such that the detent element of the selector lever in this position of the bevel contour is effectively in engagement only with the notched contour. Furthermore, the actuating device is formed by an actuator-controlled block for locking the notched contour in its first position near the detent element. The spring-loading of the displaceable notched contour is effectively weaker than the spring-loading of a detent element, and the first detent position of the notched contour (relative to the detent element of the selector lever in its first detent position) coincides with the first detent position of the bevel contour. [0014] Due to the simultaneous engagement of the detent element disposed at the selector lever in the two notched contours of the detent mechanism, and due to the actuating relative displaceability of the two notched contours, the two notched contours of the detent mechanism can thereby be brought into simultaneous, or selectively into engagement with the detent element of the selector lever. In particular, both notched contours of the detent mechanism—for the purpose of the normal operation of the selector lever—are displaceable relative to each other so that the bevel contour is mostly overlapped by the notched contour, that is, the detent element of the selector lever is in effective engagement only with the notched contour. This means that the detent element of the selector lever in any shift position of the selector lever locks into a corresponding indentation of the notched contour, and therefore the selector lever initially remains stable in the respectively selected position. [0015] However, if the selector lever now—e.g., in the case of Auto-P—is to be moved automatically back out of a shift position (or out of one of the shift gates) into the park lock position (or into the first shift gate), the notched contour can be moved for this purpose—relative to the bevel contour or relative to the housing base—so that the detent element of the selector lever is no longer in engagement with the notched contour, but instead is now in effective engagement with the bevel contour. Due to the incline of the bevel contour and the spring-loading of the detent element this leads to the detent element of the selector lever sliding on the bevel contour downward in the direction of the incline, whereby the selector lever is automatically set into motion, and only comes to rest in the position or the shift gate in which it corresponds to the appropriate first detent position of the bevel contour, or its lowest position. [0016] The constructively very simple representation of the automatic selector lever return that is the goal of the invention results because the bevel contour according to the invention is connected substantially rigidly to the housing base, whereas the notched contour is spring-loaded and disposed movable relative to the housing base—and thus also relative to the bevel contour connected to the housing base—and can be locked in its position near the detent element by means of an actuating block. [0017] Thus, according to the invention—for returning the selector lever into its first detent position—complex actuators, particularly, motors with gearing reduction or the like, are no longer necessary. Rather, the actuator for relative movement of the two notched contours can, due to the invention, be limited to simple locking of the movable notched contour in its position near the detent element. Thus, for returning the selector lever it is only necessary to release the locking of the movable notched contour by means of a simple actuator, whereupon the actual return movement of the selector lever can then occur due to the potential energy stored in the spring of the selector lever detent element. [0018] This is possible particularly because the spring-loading of the displaceable notched contour is effectively weaker than the spring-loading of the detent element at the selector lever, and also because the first detent position of the notched contour matches the first detent position of the bevel contour. Due to the effectively weaker spring-loading of the displaceable notched contour with respect to the selector lever detent element, the displaceable notched contour after releasing its locking is automatically disengaged by the spring-loaded detent element of the selector lever, and as a result the detent element comes into effective engagement with the bevel contour. Due to the incline of the bevel contour and due to the spring-loading of the detent element, this results in the return of the selector lever into the desired first lock position or first shift gate. [0019] If the selector lever has reached the desired first detent position or shift gate, that is, the detent element of the selector lever has arrived at the first detent position or at the lowest location of the bevel contour, then the displaceable notched contour, due to its spring-loading, can return again into its starting position because the first detent position of the notched contour in its starting position coincides, according to the invention, with the first detent position or with the lowest location of the bevel contour. [0020] The actuating block for locking the notched contour in the first position near the detent element is preferably formed by an armature of an electromagnet. In this manner, a constructively simple and robust representation of the actuator control of the displaceable notched contour is obtained. However, other actuators could be used just as well, for instance, linear drives, piezo elements, memory alloys, or electric motors, e.g., having locking cams. [0021] Further, the invention is implemented independent of how the spring-loaded detent element disposed on the selector lever is constructively formed, so long as the required simultaneous or parallel engagement into the notched contour and into the bevel contour can be guaranteed. According to a preferred embodiment of the invention, however, the selector lever has a substantially cylindrical or prismatic elongated shape having a substantially constant cross-section. The detent element is preferably formed as a spring-loaded detent roller. [0022] A substantially cylindrical or prismatic shape of the detent element is constructively easy to implement, and with it, can simply guarantee the simultaneous engagement in the notched contour and the bevel contour. The design of the detent element as a spring-loaded detent roller is advantageous in that only low frictional losses arise between the detent element and the notched contour or the bevel contour, whereby a reliable return of the selector lever into the desired first detent position or shift gate is guaranteed. [0023] The actuator system according to the invention is not limited to use of a selector lever with the change of detent positions, instead it can be used equally well—with an operating device having a plurality of shift gates—for an automatic lever return into a specific shift gate. Accordingly, in a further embodiment of the invention, the detent mechanism is designed for locking the selector lever into at least two shift gates. [0024] In a corresponding double design of the detent mechanism, a return through actuation of the selector lever into both a specific shift gate as well as into a specific detent position within a shift gate can be implemented. [0025] In a further embodiment of the invention, the actuator device comprises a crosspiece for guiding the selector lever, where a locking clip is disposed on the crosspiece. The locking clip can be locked to the housing base using a locking actuator. This way, the crosspiece, and with it, the selector lever can be locked in one of the detent positions or shift gates, whereby particularly shift interlocks, for instance shift lock, or blocking a change of shift gates into specific shift gates can be implemented in a simple manner, so that, for example, it is possible to switch into the manual tip gates only from the shift position “D” of the automatic gates, and not however from the shift positions “P”, “R” or “N”. [0026] Preferably the locking actuator is formed by the end of an armature of an electromagnetic actuator which can be brought to engage with the locking clip disposed on the crosspiece. The operating device particularly preferably comprises an electromagnetic actuator which serves both for locking the notched contour and for the locking engagement with the locking clip, and thus for blocking the selector lever in the first detent position or shift gate. [0027] The advantageous double function design of the electromagnetic actuator is attained in that both ends of the armature of the actuator are used functionally, in that the one end of the armature is designed for locking the notched contour and the opposite end of the armature is designed for locking engagement with the locking clip. [0028] Because the locking of the notched contour is only released through actuation if the selector lever is not located in the first detent position or shift gate, whereas the locking engagement of the armature, in contrast occurs only if the selector lever is located in the first detent position or shift gate, the double use of the common armature does not lead to undefined shifting states or undesired blocks of the shift lever. BRIEF DESCRIPTION OF THE DRAWINGS [0029] The invention is explained below in greater detail with reference to drawings that merely depict examples of embodiments. They show: [0030] FIG. 1 a schematic, isometric view of one embodiment of an operating device according to the present invention; [0031] FIG. 2 a crosspiece and detent mechanism of the operating device according to FIG. 1 in a view and representation corresponding to FIG. 1 ; [0032] FIG. 3 a schematic, isometric view of both notched contours and the magnet actuator of the detent mechanism, with activated notched contour; [0033] FIG. 4 the two notched contours and the actuator, with activated bevel contour in a view and representation corresponding to FIG. 3 ; [0034] FIG. 5 a schematic, isometric side view of the crosspiece, magnet actuator and locking clip of the operating device according to FIG. 1 to 4 ; and [0035] FIG. 6 the magnet actuator and the two notched contours of the operating device according to FIG. 1 to 5 in an enlarged representation and view corresponding to FIG. 5 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0036] FIG. 1 shows, in a schematic, isometric depiction one embodiment of an operating device according to the present invention. For better understanding and improved clarity, parts of the housing base 14 , the crosspiece 1 and the selector lever 2 are not shown in FIG. 1 . [0037] Here, the actuation lever or selector lever 2 can be seen mounted in a crosspiece 1 . The selector lever 2 , due to its mounting in the crosspiece 1 , can be moved about a first pivot axis 3 back and forth relative to the direction of travel 4 of the motor vehicle, while the crosspiece 1 together with the selector lever 2 can pivot laterally back and forth about a second pivot axis 5 . In this manner, the two degrees of freedom of movement of the selector lever 2 are defined—for example, within a typical shift pattern of a manual gear actuation, or in the shift pattern of an automatic transmission having an additional manual shift gate. [0038] The operating device according to FIG. 1 has two detent mechanisms. The first detent mechanism 6 , having a spring-loaded interlock pin 7 , serves for locking the selection lever 2 during movement forward or backward, relative to the vehicle, of the selector lever about the first pivot axis 3 , see vehicle direction 4 . In the embodiment shown, the first detent mechanism 6 is a monostable detent mechanism in which, in the absence of external forces, the selector lever 2 , due to the shape of the notched gate 8 , always returns again to its neutral central position along the vehicle direction 4 . [0039] The second detent mechanism 9 serves for locking the selector lever 2 in the transverse direction, in the case of sideways movements of the selector lever 2 about the second pivot axis 5 , that is, during shift gate changes of the selector lever 2 . [0040] The second detent mechanism 9 is shown again in FIG. 2 , together with the essential components of the crosspiece 1 . First, the crosspiece 1 can be seen, having the two pivot axes 3 and 5 . Further, a bearing element 10 in spring-loaded connection to the crosspiece 1 by means of a compression spring (not shown) and having a detent roller 11 mounted therein in a rotational manner, can be seen in FIG. 2 , as well as a notched contour arrangement comprised of the notched contours 12 and 13 . The arrangement of the two notched contours 12 and 13 is emphasized again very clearly in the FIGS. 3 and 4 . [0041] With lateral movements of the selector lever 2 and with it also, the crosspiece 1 , the bearing element 10 with the detent roller 11 pivots sideways—about the pivot axis 5 , in the opposite direction to the movements of the selector lever 2 —whereby the detent roller 11 moves into the area of the contours of the notched contour arrangement 12 and 13 and in the process contacts the respectively active notched contour of the two contours 12 , 13 . [0042] FIG. 3 shows in particular the manner in which the notched contour arrangement is composed of the two notched contours 12 and 13 . It can be recognized that the first notched contour 12 , which according to the invention represents the bevel contour 12 for returning the selector lever 2 into the first shift gate, is securely fastened to the housing base of the operating device (or to the actuator housing 14 , which here is formed integrally with the housing base of the operating device). In contrast, the second notched contour, which according to the invention forms the notched contour 13 for locking the selector lever 2 in the shift gates, is connected to the housing base or to the actuator housing 14 in a pivotable manner about the axis 15 according to FIGS. 3 and 4 . [0043] The notched contour 13 is spring-loaded by means of a coil spring 16 in the direction of its upper position, with respect to the drawing, and is additionally secured in this upper position by the end of an armature pin 17 of an electromagnetic actuator 18 , as shown in FIG. 3 . It can be seen that the bevel contour 12 in the relative position of the two notched contours 12 , 13 shown in FIG. 3 is overlapped by the notched contour 13 , whereby the detent roller 11 initially contacts only the notched contour 13 , and initially remains unaffected by the bevel contour 12 . [0044] This means, in other words, that in the relative position of the two notched contours 12 and 13 shown in FIG. 3 , normal, bistable locking of the detent roller 11 and with it, the crosspiece 1 as well as the selector lever 2 , occurs in the two shift gates of the represented operating device, so long as the notched contour 13 is located in the upper, locked position, relative to the drawing according to FIG. 3 . [0045] If in contrast, the selector lever 2 moves under actuator control out of the shift gate according to the representation in FIG. 1 and automatically returns into the other of the two shift gates of the represented operating device, then, the magnetic actuator 18 is activated for this purpose, whereby the armature pin 17 is pulled back, and the notched contour 13 is released. Because the coil spring 16 of the displaceable notched contour 13 is effectively weaker than the downward, relative to the drawing, acting spring-loading of the detent roller 11 or of the bearing element 10 , this leads to the enabling of the movement of the notched contour 13 by the then retracted magnet actuator 18 , leading to that fact that the notched contour 13 is pressed or pivoted downward, relative to the drawing, about its pivot axis 15 , due to the spring force of the spring-loaded detent roller 11 . [0046] This results in the changed relative position between the notched contour 13 and the bevel contour 12 , as shown in FIG. 4 . In this relative position of the notched contour 13 and the bevel contour 12 , the detent roller 11 interacts directly with the bevel contour 12 , whereas the locking effect of the notched contour 13 is temporarily suspended. [0047] Due to the spring-loading of the detent roller 11 , this leads to the fact that detent roller 11 glides along the incline of the bevel contour 12 , downward, and thus is deflected toward the left, relative to the drawing. As a result, the crosspiece 1 undergoes a rotation about the second pivot axis 5 (clockwise relative to the drawing), whereby the desired shift gate change of the selector lever 2 occurs automatically. [0048] Because the shape of the notched contour 13 at its first detent position coincides with the lowest position of the bevel contour 12 , when the notched contour 13 is located in its first position near the detent element (see FIG. 3 in the area of the dotted line), the notched contour 13 can, after completion of the shift gate change of the selector lever 2 , return automatically from its position according to FIG. 4 into the position according to FIG. 3 due to the spring effect of the coil spring 16 . Similarly, the armature pin 17 of the magnet actuator 18 , in the relative position of the notched contours 12 , 13 according to FIG. 4 still blocked in its retracted position, can return again into its starting position according to FIG. 3 , in which it again fixes the notched contour 13 in its upper position, relative to the drawing, near the detent element. Thus, immediately after the actuator triggered automatic shift gate change of the selector lever 2 , the normal operational readiness and locking of the operating device is restored. [0049] FIG. 5 shows the locking clip 19 , additionally present in this embodiment of the operating device, with which the selector lever 2 can be locked in the position of the first shift gate (see the dotted line in FIG. 3 ), e.g., in order to block under specific state conditions the change into the manual shift gate (for example, the selector lever in one of the “P”, “R” or “N” positions). The locking clip 19 , whose movable pivot connection to the crosspiece 1 by means of the pivot axis 20 is seen in FIG. 1 , comprises, for the purpose of locking, a bore in the extension of the armature pin 17 of the magnet actuator 18 , not visible in the figures. [0050] During activation of the magnet actuator 18 , not only is the notched contour 13 unlocked, as described above based on the description of FIGS. 3 and 4 , but simultaneously the rear end, relative to the FIG. 1 to 4 , of the armature pin 17 of the magnet actuator 18 , is deployed, see FIG. 6 . As a result, this end of the armature pin 17 can travel into the associated bore of the locking clip 19 , as soon as the actuating lever 2 , and with it the crosspiece 1 , are located in the position that coincides with the first shift gate (see dotted line in FIG. 3 ). Through this, the crosspiece 1 and actuating lever 2 —by means of engagement of the armature pin 17 in the locking clip 19 —are then locked in the first shift gate so long as the magnet actuator 18 remains activated, for example, as long as the selector lever is located in one of the positions “P”, “R” or “N”, for the case that the change into the manual shift gate is to be possible only from the selector lever position “D”. [0051] To facilitate and ensure the locking of the armature pin 17 of the magnet actuator 18 in the locking clip 19 , the end of the locking clip 19 is sloped, and the locking clip 19 is spring-loaded, and connected to the crosspiece 1 , pivotable about the pivot axis 20 according to FIG. 1 . In this manner, the locking clip can engage into the armature pin 17 even when the armature pin 17 is already deployed, when the actuating lever 2 and crosspiece 1 move out of the second shift gate back into the first shift gate. With the same effect, the armature pin 17 —instead of the locking clip 19 —can also be spring-loaded in a suitable manner, so that it can be initially displaced by the incline of the locking clip during the return movement of the crosspiece 1 , and subsequently can travel into the bore of the locking clip 19 . [0052] FIG. 6 shows again the unit comprised of the actuator housing 14 and bevel contour 12 assembled with the magnet actuator 18 and the notched contour 13 that is attached pivotably at the actuator housing 14 and bevel contour 12 . Here, the armature pin 17 of the magnet actuator 18 can be seen which is extended backwards and which in this position can travel into the above named bore of the locking clip 19 , and which this way locks the locking clip 19 and the crosspiece 1 connected to the locking clip 19 according to FIG. 5 in the first shift gate. [0053] As a result, it is clear that the invention creates an operating device with which the desired actuating positions or shift gate changes can be implemented with low design cost, with minimal construction space and at the same time also being nearly silent. The invention therefore contributes to the improvement of ergonomics and safety, as well as the efficient use of construction space, and cost effectiveness, in particular in the case of applications in the field of shift actuators of motor vehicles. LIST OF REFERENCE CHARACTERS [0000] 1 Crosspiece 2 Actuating lever, selector lever 3 Pivot axis 4 Direction of travel 5 Pivot axis 6 Detent mechanism 7 Interlock pin 8 Notched gate 9 Detent mechanism 10 Bearing 11 Detent roller 12 Bevel contour 13 Notched contour 14 Actuator housing, housing base 15 Pivot axis 16 Coil spring 17 Armature pin 18 Magnet actuator 19 Locking clip 20 Bearing axis

An operating device for shift-by-wire transmission comprises a selector lever which has a detent mechanism. The detent mechanism comprises bevel and notched contours that can be displaced for automatically returning the selector lever back to the first lock position or shift gate. The notched contour is spring-biased toward the selector lever detent element and overlaps the bevel contour in its first position, and an actuating block is provided for locking the notched contour in its first position near the detent element. The spring-loading of the notched contour is weaker than the spring-loading of the detent element, and the shape of the first detent position of the notched contour matches that of the first detent position of the bevel contour when the notched contour is located in the first position. The operating device enables actuator-controlled automatic return, and optional locking of the selector lever with little design effort, while simultaneously having low space requirements and minimal generation of any disturbing noise.

BACKGROUND OF THE INVENTION The present invention relates to moisture-curing, polyurethane hot-melt adhesive compositions based on polyethers. Hitherto hot-melt materials including eva, polyester or polyamide have been used for fast bonding processes and automatic adhesive application requiring quick setting bonds but these have usually been applied at temperatures of about 150°-200° C. For example, solvent-free reactive polyurethane hot-melt materials, such as are disclosed in German Specification DOS 2609266, solve the problem of high application temperatures by application of a low-viscosity hot melt at 100° C. which sets by crystallisation. Such adhesive systems exhibit good thermolytic and hydrolytic stability when chain-extended and cross-linked by atmospheric moisture. However, bonds provided by these crystallising polyurethane prepolymers have low elasticity before curing resulting in low initial peel strength immediately after bonding and have a lower setting rate which depends on the crystallisation rate of the polyester used. Other reactive crystalline polyurethane hot melts, such as the adhesive compositions disclosed in German Specification DOS 3236313, do show a better elasticity in the uncured state but have an undesirably high application temperature (approaching those of conventional hot-melt materials) and exhibit pot life problems at application. It is accordingly an object of the present invention to provide quick-setting, hot-melt adhesive compositions comprising polyurethane pre-polymers which have improved flexibility immediately after bonding whilst being heat stable and resistant to hydrolytic and chemical attack after curing. Our copending U.S. patent application Ser. No. 347124 filed May 4, 1989 now U.S. Pat. No. 4,999,407 describes and claims a quick setting, hot-melt polyurethane adhesive composition comprising a mixture of at least two amorphous polyurethane prepolymers, each polyurethane prepolymer providing a different glass transition point for said composition. Preferably the first polyurethane prepolymer has a glass transition point above room temperature and a second polyurethane prepolymer has a glass transition point below room temperature. These products are fast setting with high elasticity, even before curing. Polyethers such as polypropylene oxide, polyethylene oxide or polyoxybutylene have low glass transition temperatures and little if any crystallinity and thus do not seem to lend themselves to the preparation of hot-melt compositions. SUMMARY OF THE INVENTION According to the present invention a quick-setting, hot-melt polyurethane composition comprising a mixture of at least two polyurethane prepolymers is characterised by a first polyether-based polyurethane prepolymer having a glass transition point above room temperature and a second polymer or polyurethane prepolymer with a glass transition point below room temperature. Polyurethane prepolymers with Tg above room temperature may be prepared from low molecular weight polyethers (MW less than 1000) and polyisocyanates. Polyurethane prepolymers with Tg below room temperature may be prepared from high molecular weight polyethers, polyesters or polybutadienes and polyisocyanates. Preferably the second polyurethane prepolymer is also polyether based and prepared from high molecular weight polyether (MW greater than 1000) and polyisocyanates. A prepolymer with Tg above room temperature sets quickly on cooling down from the application temperature but gives a brittle bond at room temperature. A prepolymer with Tg below room temperature may be applied at a relatively low temperature, even as low as room temperature but the applied film tends to remain tacky and to remain elastic when cured. Such bonds are flexible down to the low glass transition point and little or no cohesion is observed before curing. A composition according to the present invention provides an optimisation of these two sets of properties, giving a fast-setting adhesive curing with atmospheric moisture to give flexible bonding over a wide temperature range. The compositions according to the present invention also avoid the hydrolytic degradation to which polyester polyurethanes are susceptible. Compositions according to the present invention may be prepared either by mixing two separately-prepared prepolymers or by a combined, one-shot procedure, depending on the polyols used. The first polyurethane prepolymer with a high Tg (above room temperature) is prepared from a polyether polyol and a polyisocyanate. The polyol has a molecular weight between approximately 200 and 1000, preferably 250 and 800, most preferably approximately 400. Prepolymers of such products have a Tg above room temperature if NCO/OH ratio is kept sufficiently low. Reducing molecular weight of polyols and NCO/OH-ratio of prepolymers increases the Tg of prepolymers. Such products require higher application temperatures, are faster setting and give bonds which are more brittle. Prepolymers based on typical chain extenders such as propylene glycol are not suitable for the present invention. The polyols used may be any type of polyetherpolyols such as polypropylene oxide, polyethylene oxide polyoxybutylene or copolymers. Polyethyleneglycol-based products are less suitable because of their high water absorption. The polyisocyanate is preferably an aromatic diisocyanate such as 4.4'-diphenylmethane- or 2.4'-toluenediisocyanate. Derivates with functionalities higher than two may also be used if NCO/OH-ratios for synthesis are kept sufficiently high. Aliphatic polyisocyanates can also be used but are generally found to be less suitable. The prepolymer with the high (above room temperature) glass transition point is prepared at a NCO/OH ratio of 1.1 to 2.0, preferably 1.15 to 1.5 and at temperatures above the application temperature of the final product, preferably between 80° and 140° C. For prepolymer synthesis, no catalyst is required but for faster curing of the final product any catalyst suitable for one part polyurethanes can be added in a quantity of 10-10,000 ppm, preferably 100-1000 ppm. For prepolymer synthesis from polyethers special stabilization is recommended. A variety of stabilizers like acids, β-dicarboxylic compounds and reactive isocyanates, as well as antioxidants, may be used. The polyurethane prepolymer with the low (below room temperature) glass transition point is also a reaction product of a polyol and a polyisocyanate. The polyol may be a linear or slightly branched polyether, polyester, polybutadiene or another OH-terminated polyol. Again polypropylene oxide, polyethylene oxide polyoxybutylene or copolymers are suitable polyethers and these have a molecular weight of more than 800, preferably more than 1000. Although polyether based polyurethanes are preferred, polyurethane prepolymers with Tg below room temperature based on polyesters or polybutadienes can be used for the present invention as well as non reactive polymers with low Tg like polyolefins and their copolymers, high molecular weight polyesters, polyethers or polyurethanes. Generally we prefer to use diols in the compositions of the invention, but the use of polyols with higher functionality can result in superior final bonding properties due to crosslinking facilities (for details see examples described hereafter). The polyisocyanate used to prepare the compositions of the invention is preferably an aromatic diisocyanate such as 4.4'-diphenylmethane diisocyanate or 2.4-toluene diisocyanate or derivates with functionality higher than two but aliphatic diisocyanates may also be used. The prepolymer is prepared at a NCO/OH ratio between 1.1 and 3, preferably 1.2 and 2.5 and at temperatures between room temperature and 140° C., preferably between 60° and 100° C. using stabilization as mentioned above, and with or without typical catalysts. The final product properties depend significantly on the types and mixing ratio of high and low Tg-prepolymers. If more prepolymer with high glass transition point is used, the adhesive is more viscous and initial strength is superior. Bonds are tougher but they are more inclined to be brittle at lower temperatures. By using more prepolymer with a lower Tg, the adhesive becomes less viscous, initial strength is lower and bonds are softer and more flexible. After application of the adhesive, the curing reaction with atmospheric moisture starts. Isocyanate reacts with water and carbon dioxide is formed. This often leads to unwanted foaming of the adhesive during curing. The degree of foaming depends on the quantity of carbon dioxide liberated, the reaction rate and the diffusion characteristics of the polymer system. The quantity of carbon dioxide can be controlled by NCO/OH ratio of prepolymers and molecular weight of polyols. The final product may also include usual and ingredients such as fillers, tackifying resins or plasticizers. The resulting mixture is usually transparent at room temperature and applied above the high Tg, preferably between 90° and 140° C. DETAILED DESCRIPTION OF THE INVENTION In order that the invention may be better understood preferred Examples will now be described in greater detail. EXAMPLE I Prepolymer A1 (Low Tg) 800 g (428 mVal) polypropylene oxide of molecular weight 4000 and 4.5 g toluolsulfonyl isocyanate are placed in a closed reactor at 60° C., 107 g (855 mVal) methylene diphenyl diisocyanate (MDI) are added and the temperature raised to 110° C. for two hours. 1.8 g dibutyl tin dilaurate (DBTL) are added and stirred for further 15 minutes at 110°-115° C. under vacuum. The prepolymer has a viscosity of 620 mPas at 130° C., a NCO-content of 406 mVal/kg and a glass transition point of approximately -60° C. Prepolymer B (High Tg) 351.3 g (2806 mVal) MDI are melted at approximately 40° C. in a closed reactor. 4.3 g toluolsulfonyl isocyanate and 500 g (2375 mVal) polypropylene oxide of molecular weight 400 are added. After heating one hour at approximately 60° C. and one hour at 120° C., 0.9 g DBTL are added and stirring at 120° C. is continued for 20 minutes. The prepolymer has a viscosity of 22 Pas at 130° C., a NCO content of 520 mVal/kg and a glass transition point of approximately +22° C. Formulation of Adhesive Composition (I) 93.7 g of the prepolymer A1 are added to 856.5 of the prepolymer B at 120°-125° C. and stirred for approximately one hour. The mixture is a colourless, transparent liquid at 130° C. with a viscosity of 12 Pas and a NCO-content of 485 mVal/kg. Differential Scanning Calorimetry (DSC) shows a glass transition point of approximately +7° C. The adhesive sets quickly and has good bond strength over a wide range of temperatures. (See the following tables). Foaming during curing is negligible if the thin layers of adhesive are applied. EXAMPLE II Prepolymer A2 (Low Tg) 80.4 g (642 mVal) MDI are melted at 44° C. 2.4 g toluolsulfonyl isocyanate and 400 g (257 mVal) polypropylene oxide (triol) added. The temperature is raised to 117° C. for approximately 1 hour. The prepolymer has a viscosity of 375 mPas at 130° C. and a NCO-content of 829 mVal/kg. Formulation of Adhesive Composition (II) 860.6 g prepolymer B from Example I are placed in a reactor at 130° C., 107.7 g prepolymer A2 are added and stirring is continued for 2 hours. The mixture is a colourless, transparent liquid at 130° C. with a viscosity of 12 Pas and a NCO content of 554 mVal/Kg. The adhesive sets quickly and has good bond strength over a wide range of temperatures. High temperature strength is improved (see following tables). Foaming is avoided by applying the adhesive thinly. EXAMPLE III Prepolymer A3 (Low Tg) 800 g (507 mVal) of an amorphous polyester from 1.6 hexane diol and a mixture of adipic acid and isophthalic acid with a molecular weight of 3500 sulfonyl isocyanate 4.6 g p-toluol are placed at 80° C. in a reactor with 127 g (1015 mVal) MDI are added under stirring and the temperature raised to 80° C. for 30 min and then to 127° C. for 45 min. After degassing under vacuum, a prepolymer A3 with a viscosity of 9 Pas at 130° C. and a NCO content of 555 mVal/kg is obtained. Formulation of Adhesive Composition (III) 855 g prepolymer B according to example I are placed in a reactor of 130° C. and 92.7 g prepolymer A3 are added and stirred for 1.5 hours at 130° C. The mixture is a colourless, transparent liquid at 130° C. with a viscosity of 20 Pas and a NCO content of 500 mVal/kg. The adhesive sets quickly and has good bond strength to a variety of plastics. (see following tables) Foaming during curing is avoided by applying the adhesive thinly. EXAMPLE IV (One-Shot Procedure) 500 g (2375 mVal) polypropylene oxide diol of molecular weight 400 and 90.2 g (48 mVal) of a polypropyleneoxide diol with molecular weight 4000 are placed in a closed reactor at 70° C. After addition of 4.8 g toluolsulfonyl isocyanate 368 g (2940 mVal) MDI is added under stirring. The temperature is raised to 105° C. and stirring is continued for 1 hour. 1.19 DBTL is then added and stirring is continued for 1 hour at 110° C. After degassing under vacuum, a prepolymer with viscosity of 6.8 Pas at 130° C. and a NCO content of 539 mVal/kg is obtained. The adhesive is colourless and transparent with good initial and final bonding properties. (see following tables) Foaming during curing is avoided by applying the adhesive thinly. TABLE 1______________________________________Initial Strength (measured after 10 minutes) Tensile shear strength Peel strength Wood canvas (N/mm.sup.2) (N/mm)______________________________________EXAMPLE I 1.8 2.8EXAMPLE II 1.0 3.0EXAMPLE III 1.5 0.8EXAMPLE IV 0.6 1.5______________________________________ TABLE 2______________________________________Final Bond Strength Tensile shear strength (wood) (N/mm.sup.2) r.t. 100° C. 150______________________________________EXAMPLE I 7.8 1.6 1.3EXAMPLE II 8.4 1.9 1.4EXAMPLE III 10.2 0.8 0.7EXAMPLE IV 8.8 not determined______________________________________ TABLE 3______________________________________Hydrolysis ResistanceTensile shear strength of beechwood bonds after hydrolysisB 4/10-test according to DIN 68602 (six hours boilingwater, seven days drying at room temperature)______________________________________ EXAMPLE I 7.7______________________________________ The adhesive composition of Example I was assessed for resistance to hydrolysis by measuring tensile shear strength of beechwood bonds after hydrolysis. The assessment was carried out by the B4/10 test according to DIN 68602 and the tensile shear strength measured after six hours in boiling water followed by seven days drying at room temperature. The results showed a tensile shear strength of 7.7 N/mm 2 .

A quick-setting, moisture-curing hot-melt polyurethane composition having a first polyether-based polyurethane prepolymer having a Tg above room temperature and a second polyurethane prepolymer with a Tg below room temperature, the first prepolymer being prepared from a low molecular weight polyether; preferably the second prepolymer is also polyether based and prepared from a high molecular weight polyether.

This is a division of application Ser. No. 807,064, filed on Feb. 18, 1986, now U.S. Pat. No. 4,631,345, which is a division of application Ser. No. 587,757, filed on May 17, 1984, now U.S. Pat. No. 4,581,459, which is a division of application Ser. No. 379,247, filed May 17, 1982, now U.S. Pat. No. 4,468,516. BACKGROUND OF THE INVENTION Biotin is a water-soluble vitamin required by higher animals and by many microorganisms. Biosynthesis of biotin by selected yeasts, molds and bacteria is well known. U.S. Pat. No. 3,393,129 reports the use of a d-biotin-producing strain of bacteria of the genus Sporobolomyces for commercial production of this vitamin. Chemical synthesis is reported in U.S. Pat. Nos. 2,489,235; 2,489,236; 4,029,647 and 4,124,595. As industrial demand for d-biotin increases, the search for improved synthetic processes continues. SUMMARY OF THE INVENTION The present invention relates to a novel process for the preparation of biotin and novel intermediates useful therein. One class of intermediates of the present invention are novel compounds of formula II ##STR1## wherein X is sulfur or oxygen; R 1 is --(CH 2 ) 4 CH 3 , or --(CH 2 ) 3 OR or --(CH 2 ) 5 OR wherein R is alkyl, or --(CH 2 ) 4 CN, or --(CH 2 ) 4 COOR' wherein R' is alkyl or phenyl; R 2 and R 3 when taken together are cycloalkyl or --CH 2 --CH 2 --Y--CH 2 --CH 2 wherein Y is sulfur, oxygen or NR" wherein R" is COOR"' wherein R"' is alkyl, or R 2 and R 3 when taken separately, are each alkyl, cycloalkyl or phenyl, provided that R 2 and R 3 are not both phenyl; R 4 is hydrogen, alkyl, alkoxyalkyl, cycloalkyl, monoalkyl, substituted cycloalkyl, phenyl or mono-, di or trialkyl substituted phenyl; and when R 4 is hydrogen, the addition salts thereof; said alkyl and alkoxy having from 1 to 4 carbon atoms and said cycloalkyl having from 5 to 7 carbon atoms. Preferred compounds include those wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOR' wherein R' is alkyl; R 2 and R 3 when taken together are cycloalkyl, or R 2 and R 3 when taken separately are each alkyl; and R 4 is alkyl. Especially preferred of these compounds are those wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 ; R 2 and R 3 when taken together are cyclohexyl, or R 2 and R 3 taken separately are each methyl; and R 4 is ethyl. Also within the scope of the present invention are intermediates useful for the preparation of thiazoles of formula II. Thus, the present invention includes compounds of formula I ##STR2## wherein R 1 , R 2 and R 3 are as previously defined; R 2 and R 3 when together together are cycloalkyl or --CH 2 --CH 2 --Y--CH 2 --CH 2 wherein Y is sulfur, oxygen or NR" wherein R" is COOR"' wherein R'" is alkyl; or R 2 and R 3 when taken separately are each alkyl, cycloalkyl or phenyl, provided that R 2 and R 3 are not both phenyl; said alkyl having from 1 to 4 carbon atoms and said cycloalkyl having from 3 to 7 carbon atoms. Also included in the present invention are the boron trifluoride adducts of compounds of formula I, especially those wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOR' wherein R' is alkyl; and R 2 and R 3 when taken together are cycloalkyl, or R 2 and R 3 when taken separately are each alkyl. Preferred compounds include those wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 ; and R 2 and R 3 when taken together are cyclohexyl, or R 2 and R 3 when taken separately are each methyl. The present invention also includes a process for the preparation of compounds of formula II comprising contacting a boron trifluoride adduct of a compound of formula I with a compound of the formula M[R.sub.4 O.sub.2 C--CH--A] wherein A is --N═C═O, --N═C═S, --N═S═O, --N--CO 2 R 7 , or --N═C(H)R 7 wherein R 7 is alkyl or phenyl; M is a metal selected from lithium, sodium, potassium, zinc, magnesium or zirconium or a counterion of the formula N(R 8 ) 4 + or B(R 8 ) 2 wherein R 8 is an alkyl group having from 1 to 4 carbon atoms; and R 4 is as previously defined. A further class of intermediates useful in the process of the present invention are novel compounds of formula III ##STR3## wherein X, R 1 , R 2 and R 3 are as previously defined. Preferably R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOR' wherein R' is alkyl; R 2 and R 3 when taken together are cycloalkyl, or R 2 and R 3 when taken separately are each alkyl. Especially preferred are compounds wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 ; and R 2 and R 3 when taken together are cyclohexyl or R 2 and R 3 when taken separately are each methyl. Further intermediates of the present invention are novel compounds of formula IV ##STR4## wherein X, R 1 , R 2 and R 3 are as previously defined; and R 5 is --C(O)R 6 or --SO 2 R 6 wherein R 6 is alkyl, haloalkyl, phenyl or mono- or dialkyl substituted phenyl or camphoryl; said alkyl having from 1 to 4 carbon atoms and said cycloalkyl having from 5 to 7 carbon atoms. Preferred compounds include those wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOR' wherein R' is alkyl; R 2 and R 3 when taken together are cycloalkyl, or R 2 and R 3 when taken separately are each alkyl; and R 5 is acetyl, mesyl, tosyl or camphorsulfonyl. Especially preferred are compounds wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 ; and R 2 and R 3 when taken together are cyclohexane or R 2 and R 3 when taken separately are each methyl; and R 5 is --SO 2 R 6 wherein R 6 is d-10-camphoryl. Further intermediates of the present invention are novel compounds of formula V ##STR5## wherein X and R 1 are as previously defined and R 5 is as previously defined or hydrogen. Preferred compounds include those wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 ; and R 5 is hydrogen, acetyl, mesyl, tosyl or camphorsulfonyl. Especially preferred are compounds wherein R 1 is --(CH 2 ) 4 CH 3 and R 5 is d-10-camphorsulfonyl or hydrogen. Further intermediates of the present invention are those of formula VI ##STR6## wherein X and R 1 are as previously defined, provided that when R 1 is (CH 2 ) 4 COOR', R' is alkyl having from 2 to 4 carbon atoms. Also included in the present invention are processes for preparation of compounds of Formula VI by cyclizing intermediate compounds of formula V. Further intermediates of the present invention are compounds of the formula ##STR7## wherein X and R 1 are as previously defined and Y is ═O, formula VIII, or Y is --H and --OH, formula IX. Compounds VI may also be prepared by reducing a thiolactone of formula VIII in a reaction inert solvent with an alkali metal borohydride followed by treatment with an electropositive metal in the presence of an acid. Compounds VI wherein X is sulfur may be converted to the oxygen analog by contacting it with a haloalcohol in the presence of weak base in a protic solvent. The present invention further comprises a method for preparation of biotin comprising contacting in solution a compound of formula IIA with an alkali metal borohydride followed by the addition of water, treating the resultant compound of formula III PG,9 with strong aqueous acid or with an alkyl or aryl sulfonyl halide or acyl halide in the presence of base, and contacting these products with strong aqueous acid, and, when X is sulfur, refluxing with a haloalcohol. The resultant compound may be hydrolyzed, treated with acid followed by sodium diethyl malonate and then hydrolyzed, or oxidized depending on the nature of the R 1 group to form biotin. In a preferred process of this invention, d-biotin may be prepared by resolving an acid of formula IIA with (d)-ephedrine, separating the resultant diastereometric mixture of compounds, esterifying the requisite stereoisomer to give a compound of formula II wherein R 4 is methyl, contacting this ester with borohyride and then acid, and when X is sulfur, treating the resultant bicyclic thiourea with a haloalcohol, and hydrolyzing or oxidizing, as appropriate in view of the nature of the R 1 group, to form biotin. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the synthesis of biotin from the intermediates described above as shown in Schemes A and B to which reference is made for the following discussion. The formulae given in these Schemes and throughout the present application conform to the accepted convention for indicating stereoisomers, namely, " " to indicate an atom projecting into the plane of the paper (α-orientation) " " to indicate an atom projecting out from the plane of the paper (β-orientation) and hence the plane of the molecule itself and "˜" to indicate a substituent which is in either the α or β-orientation. Numbering of compounds throughout this application follows the sequence given in Schemes A and B. It will be appreciated that R 2 , R 3 and R 4 groups in the compounds of formulae I to V are protecting groups which will be subsequently removed in later reaction steps. Likewise R 5 , R 6 , R, R', R" and R'' are intermediate groups in the synthesis of the final compounds. Accordingly, while intermediates having R 2 , R 3 , R 4 , R 5 , R 6 , R, R', R" and R"' substituents as previously defined are preferred for use in the present invention, the use of such substituents is not critical and other similar protecting and intermediate substituent groups may be employed in the present process to obtain biotin. For example, higher alkyl or cycloalkyl groups, up to about 17 carbon atoms, may be employed, together with substituted aryl groups, such as phenyl substituted with alkyl, halo, nitro or alkoxy groups, or naphthyl. Substituted 3H,5H-imidazo[1,5c]tetrahydrothiazoles of formula II may be prepared by contacting in a nonprotic solvent at about -100° C. to -30° C. the boron trifluoride adduct of a compound of formula I, wherein R 1 , R 2 and R 3 are as previously defined, with the metallic derivatives of an ester enolate of the formula ##STR8## wherein M + is lithium, sodium, potassium, zinc, magnesium or zirconium or a counterion of the formula N(R 8 ) 4 + or B(R 8 ) 2 wherein R 8 is an alkyl group having from 1 to 4 carbon atoms and A is --N═C═O or --N═C═S. Compounds wherein A is as defined are preferred for use in the present invention, but it will be appreciated that similar protecting groups may be employed to make the intermediates useful for the preparation of biotin by the process of the present invention, for example compounds wherein A is --N═S═O, --N--COOR wherein R is alkyl or --N═C(H)R 7 wherein R 7 is phenyl. More particularly, compounds of formula II wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOR' wherein R' is alkyl, R 2 and R 3 when taken together are cycloalkyl or --CH 2 --CH 2 --N(R")--CH 2 --CH 2 -- wherein R" is --COOR"' wherein R"' is alkyl or R 2 and R 3 separately are each alkyl, cycloalkyl or phenyl provided that R 2 and R 3 are not both phenyl; and R 4 is alkyl or phenyl may be prepared by contacting in a non-protic solvent, preferably tetrahydrofuran, the boron trifluoride adduct of a compound of formula I wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 CO 2 R' wherein R' is alkyl and R 2 and R 3 are as given above, at a temperature between about -100° C. to -0° C. preferably near -78° C. with a metallo derivative of an ester enolate of the formula ##STR9## wherein [M] is lithium, sodium, potassium, zinc or magnesium, but most preferably lithium; A, when X of the resultant compound of formula II is oxygen, is --N═C═O or A, when X of said compound of formula II is sulfur, is --N═C═S; and R 4 is alkyl or phenyl. Preferred compounds which may be prepared by this method include those wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 , R 2 and R 3 when taken together are cycloalkyl, preferably cyclohexyl or --CH 2 --CH 2 --Y--CH 2 --CH 2 -- wherein Y is NR" wherein R" is --COOR"' wherein R"' is alkyl, preferably methyl or ethyl, R 2 and R 3 when taken separately are alkyl, preferably methyl or ethyl or R 2 and R 3 when taken together are cycloalkyl, preferably cyclohexyl and R 4 is alkyl, preferably ethyl, n-propyl or isopropyl, alkoxy, preferably ethylmethoxy or alkyl substituted phenyl, preferably 2,6-di-t-butyl-4-methyl phenyl or 2-methyl-6-t-butylphenyl or cycloalkyl such as norboronyl. The boron trifluoride adduct of the compound of formula I may be prepared by combining in a suitable non-polar solvent, preferably tetrahydrofuran, said thiazoline of formula I and an essentially equimolar amount of boron trifluoride diethyl ether at a temperature between about -78° C. and 30° C. preferably about 0° C. The metallo derivative of ester enolate may be prepared by standard methods such as combining in a suitable non-polar solvent, preferably tetrahydrofuran at temperatures between about -100° C. and 10° C. preferably -78° C. an alkyl isocyanatoacetate and a metallo dialkylamide, for example lithium diisopropylamide, which in turn is generated by adding butyllithium to a dialkylamine solution. In the case of an alkyl or phenyl isothiocyanatoacetate, either a metallo dialkylamide preferably lithium di-isopropylamide or a metallo alkoxide, preferably lithium t-butoxide can be used to generate the metallo derivatives of the ester enolates. The nature of the alkyl or aryl substituent (R 4 ) present in the isothiocyanatoacetate influences the ratio of products of formulas IIA: IIB formed. For example, the ratio of IIA: IIB is 1.3:1 when methyl isothiocyanatoacetate is used and with ethyl isothiocyanatoacetate, the ratio of IIA:IIB is 3:1. Since IIA is the desired isomer in the synthesis of biotin, compounds in which R 4 is ethyl are preferred. The desired compound of formula IIA can be separated from formula IIB by standard chromatographic processes or by crystallization. The compounds of formula IIA are employed in the further synthesis of biotin. 3-Thiazolines of formula I may, in turn, be prepared according to the method of Thiel, Asinger and Schmiedel (Liebigs Ann. Chem. 611 121 (1958)) wherein 2-bromoaldehydes, compounds easily synthesized by known methods, of the formula ##STR10## wherein R 1 is as defined, is combined with sodium hydrogen sulfide and then with a carbonyl compound of the formula ##STR11## wherein R 2 and R 3 are as defined, followed by the addition of ammonia. Compounds of formula I, for example, which may be prepared by this method, are those wherein R 1 is preferably --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 ; and R 2 and R 3 together are preferably cyclohexyl or R 2 and R 3 separately are each methyl. The desired enantiomer of the compound of formula IIA required for a synthesis of d-biotin can be obtained by a resolution of racemic mixtures of IIA in which R 4 =H. The overall procedure may be accomplished, for example, by a saponification of the racemic ester IIA obtained in the imine addition reaction to form a racemic acid which when treated with a chiral base, may be separated into diasteriometric salts, which once separated may be converted to optically pure esters of formula IIA. More specifically, racemic ester IIA (R 4 =CH 2 CH 3 ) may be saponified to the corresponding racemic acid of formula IIA (R 4 =H) upon treatment with an alkali hydroxide such as sodium hydroxide in a polar solvent such as methanol or tetrahydrofuran. Treatment of racemic acid of formula IIA with an optically pure base such as d-ephedrine in a polar solvent such as ether generates a solid which can be crystallized in an optically pure form. Treatment of this salt, for example, with an alcoholic solvent in the presence of acid such as methanolic hydrogen chloride generates optically pure ester of formula IIA wherein R 4 is methyl. Compounds of formula III, 7-hydroxymethyl-3H,5H-imidazo[1,5c] tetrahydrothiazoles, may be prepared by contacting esters of formula IIA wherein R 4 is preferably ethyl or methyl in a polar solvent, preferably methanol, ethanol or tetrahydrofuran with a borohydride derivative, an alkali metal borohydride for example, wherein the alkali metal is preferably sodium, at a temperature between -10° C. and 25° C. for a period of about 1-5 hours followed by addition of water. Alternatively, optically pure acids of formula IIA may be reduced with diborane to generate III directly. Compounds of Formula III may then be converted directly to the biotin ring structure of formula VI via intermediate V. For example, alcohol III is treated with a strong acid at elevated temperatures to generate VI directly. In particular, compounds of formula VI wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 CO 2 H and X is O or S may be prepared by contacting alcohol III, wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 CO 2 R' wherein R' is preferably methyl, R 2 and R 3 when taken together are cyclohexyl, or when taken separately are alkyl preferably methyl with aqueous trifluoroacetic acid or methanesulfonic acid at temperature between about 40° to 105° C. until reaction is substantially complete. Alternatively, compounds of formula III may be converted to compounds of formula IV by contacting compounds of formula III with a sulfonyl or acyl halide in a polar solvent in the presence of a base, preferably trialkylamine. Thus compounds of formula IV wherein R 5 is SO 2 R 6 or COR 6 wherein R 6 is alkyl or haloalkyl, most preferably methyl, tolyl or camphoryl are prepared by contacting III wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 CO 2 R', R 2 and R 3 when taken together are cyclohexyl or when taken separately are alkyl, preferably methyl, in a solvent such as methylene chloride with triethylamine and an appropriate sulfonyl chloride at temperatures between about -78° to 25° C. When racemic III is treated with an optically active sulfonyl chloride, a diastereomeric mixture results which may be separated to afford optically pure compounds of formula IV of the desired chirality. For example, compound IV wherein R 5 is SO 2 R 6 and R 6 is d- or 1-10-camphoryl and R 1 is (CH 2 ) 4 CH 3 and R 2 and R 3 when taken together are cyclohexyl can easily be separated by means of silica gel chromatography to give the desired pure diastereomer of formula IV. Compounds of formula IV may then be converted directly to the biotin ring structure by treating compounds of formula IV wherein R 5 is acyl or sulfonyl in a strong acid at elevated temperatures. For example, the d-biotin framework of VI in which R 1 is (CH 2 ) 4 CH 3 may be generated by treating the requisite camphorsulfonate of formula IV in which R 1 is (CH 2 ) 4 CH 3 , R 2 and R 3 taken together are cyclohexyl, R 5 is SO 2 R 6 and R 6 is d-10-camphor with aqueous trifluoroacetic acid at temperature between about 35° to 105° C. for 1 to 24 hours. Compounds of formula VI wherein X is S may be converted to the oxygen analogue by contacting the corresponding thiourea derivative of formula VI wherein X is sulfur with a haloalcohol, preferably bromoethanol, in an polar solvent such as ethanol, methoxyethanol or diglyme, and refluxing under inert gas, preferably nitrogen, until reaction is essentially complete, from 2 to 24 hours, and then treating with a weak base, an alkali metal carbonate for example, preferably a saturated solution of sodium carbonate. The conversion of compound VI wherein X is O and R 1 is (CH 2 ) 4 CH 3 to biotin may be accomplished by a microbiological oxidation. The preferred microbiological oxidation is that disclosed in Ogino et al in U.S. Pat. No. 3,859,167, the disclosure of which is incorporated herein by reference. Accordingly, biotin wherein R 1 is (CH 2 ) 4 CO 2 H is obtained upon treatment of VI wherein R 1 is (CH 2 ) 4 CH 3 and X is oxygen with the organism Corynebacterium primorioxydans. Compound VI wherein X is S and R 1 is --(CH 2 ) 4 CH 3 may likewise be converted by microbiological oxidation by an organism such as Corynebacterium primorioxydans to the sulfur analog of biotin. A novel process is also herein presented for preparation of intermediate compounds of formula VI by reduction of the corresponding thiolactone of formula VIII A as shown in Scheme B wherein R 1 , R 2 , R 3 , R 4 and X are as previously defined. As shown in Scheme B, thiolactones of formula VIIIA wherein R 1 is (CH 3 ) 4 CH 3 may be prepared by: contacting a compound of the formula IIA wherein R 1 is --(CH 2 ) 4 CH 3 , R 2 and R 3 are each alkyl, preferably methyl, and R 4 is alkyl, preferably ethyl, with a strong acid, preferably aqueous trifluoroacetic acid at a temperature between 80° to 120° C., preferably about 100° C.; or contacting a compound of the formula IIA in a polar solvent, for example, aqueous methanol, with an essentially equimolar amount of base, preferably an alkali metal hydroxide, for a period of about 5 to 12 hours at a temperature between 20° C. to 35° C. followed by acidification to a pH between 2.0 to 3.0, preferably about 2.5 with an aqueous acid halide, preferably hydrochloric acid; and contacting the resultant carboxylic acid with acid, preferably trifluoroacetic acid with an excess molar amount of water at a temperature between 45° C. to 55° C. for about 6 to 8 hours. Alternatively, compounds of formula VIII A may be prepared by: contacting IIB in a polar solvent, for example, aqueous methanol, with an essentially equimolar amount of base, preferably an alkali metal hydroxide, for a period of 1 to 2 hours at a temperature of -0°-10° C. followed by acidification to a pH between 2.0 to 3.0, preferably about 2.5 with an aqueous acid halide, preferably hydrochloric acid; contacting the resultant acid with acid, preferably trifluoroacetic acid in an excess molar amount of water at a temperature of about 15° C.-35° C. for 2 to 3 hours; contacting the resultant thiol VIIB in a polar solvent, preferably methylene chloride, with a basic trialkyl-amine, preferably triethylamine followed by an alkylhaloformate, preferably ethyl chloroformate at a temperature between about 15° C. to 35° C. for a period of 2 to 3 hours to give lactone VIIIB which may be converted to VIIIA by contacting VIIB in a polar solvent, preferably tetrahydrofuran, with a non-nucleophalic base, for example. Intermediate compounds of formula VIIIA may be converted to intermediate compounds of formula VI by reduction. Compounds of formula VI, for example, wherein R 1 is preferably --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 may be prepared by contacting a thiolactone of formula VIIA wherein R 1 is --(CH 2 ) 4 CH 3 or --(CH 2 ) 4 COOCH 3 in a polar solvent, preferably methanol at a temperature between -10° C. to 25° C., preferably about 0° C. with a metallic borohydride, preferably sodium borohydride for a period of about one hour and contacting the resultant hemiacetal in acid solution with zinc metal under reflux for a period of 12 to 48 hours, until reduction is essentially complete. ##STR12## The present invention is illustrated by the following examples. It should be understood, however, that the invention is not limited to the specific details of these examples. EXAMPLE 1 3H, 5H-Imidazo [1, 5c] thiazole-7-carboxyic acid, tetrahydro-3, 3-dimethyl-5-oxo-1-pentyl-, ethyl ester (1α,7α,7aα) and (1α,7β,7aα). To a tetrahydrofuran solution (50 ml) containing 2,2-dimethyl-5-pentyl-3-thiazoline (5.58 grams, 30.2 mmole) at 0° C. was added boron trifluoride etherate (3.70 ml, 30.2 mmol) over a one minute period. Solution was allowed to warm to room temperature and stirred for one hour and then cooled to -78° C. Diisopropylamide was prepared by adding 2.3M m-butyllithium (13.1 ml, 30.2 mmol) to diisopropylamine (4.24 ml, 30.2 mmol) in tetrahydrofuran (300 ml) at -78° C. and stirring for 60 minutes. To this solution was added drop-wise over a period of 1 minute, ethylisocyanoacetate (3.90 grams, 30.2 mmol). This solution was stirred at -78° C. for 5 minutes and then was added over a 1 minute period to the boron trifluoridethiazoline solution. The mixture was stirred at -78° C. for two hours, allowed to warm gradually to room temperature and stirred for another 1 hour. The reaction mixture was concentrated. Ethyl acetate was added and the organic solution was extracted with 0.5N HCL, dried over magnesium sulfate and concentrated in vacuo. The crude product was purified by column chromatography on silica gel (eluant methylene chloride:ether, 3:2) to give 4.69 g (50%) of a product mixture (1:1) containing 3H, 5H-imidazo[1,5c]-thiazole-7carboxylic acid, tetrahydro-3,3-dimethyl-5-oxo-1-pentyl ethylester (1α,7α,7aα) MP 71°-73°. IR (KBr) 3267, 2926, 1731, 1704; NMR (d, CDCL 3 ) 0.6-2.4 (20H, m, CH 3 , CH 2 ) 3.2-3.7 (1H, m, CHS), 3.9-4.6 (4H, m, CHN, CHN, OCH 2 ), 5.1-5.4 (1H, m, NH). Analysis Calculated for C 15 H 26 O 3 N 2 S: C, 57.32; H, 8.28, N, 8.92. Found: C, 56.97; H, 8.12; N, 8.87; And 3H, 5H-Imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-oxo-1-pentyl-, ethylester (1α,7β,7aα), MP 74°-75° C. IR(KBr) 3280, 3926, 1731, 1705; NMR (d, CDCL 3 ) 0.66-2.25 (20H, m, CH 3 CH 2 ) 3.0-3.5 (1H, m, CHS), 3.9-4.6 (4H, m, CHN, CHN, OCH 2 ), 5.3-5.6 (1H, m, NH) Analysis Calculated for C 15 H 26 O 3 N 2 S: C, 57.32; H, 8.28; N, 8.92; S, 10.19; Found: C, 57.47; H, 8.28; N, 8.97; S, 10.18. EXAMPLE 2 3H, 5H-Imidazo [1, 5c] thiazole-7-carboxylic acid, tetrahydro-3, 3-dimethyl-5-thioxo-1-pentyl-, ethyl ester (1α,7α,7aα) and (1α,7β,7aα) 2,2-Dimethyl-5-pentyl-3-thiazoline (860 mg, 4.65 mmol) was dissolved in tetrahyrofuran (20 ml) and cooled to 0° C. Boron trifluoride etherate (0.510 ml, 4.65 mmol) was added over a one minute period. The solution was allowed to warm to room temperature for about 1.25 hour and then cooled to -78° C. In a separate flask was placed diisopropylamine (0.652 ml, 4.65 mmol) followed by tetrahydrofuran (10 ml). The solution was cooled to -78° C. 1.5M butyl lithium (3.1 ml, 4.65 mmol) was added over a 5 minute period. The solution was stirred at -78° for one hour. To this solution was added ethyl isothiocyanotoacetate (674 mg, 4.65 mol) in tetrahydrofuran (5 ml) over a 5 minute period. The solution was stirred for 25 minutes at -78° and was then added to the boron trifluoride thiazoline solution. The solution was stirred at -78° for 2 hours and quenched with acetic acid (266 ml, 4.66 mmol). The solution was allowed to warm to room temperature, concentrated in vacuo and was taken up in methylene chloride. This organic solution was washed with aqueous bicarbonate, dried over MgSO 4 and concentrated to afford a black oil which was purified by column chromatography on pH 9 silica gel (eluant methylene chloride:ether, 20:1) to give 1.030 g (67%) of a product mixture containing 278 mg (18%) of 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl; ethylester (1α,7α,7aα) which formed needles after a methanol recrystallization, mp 123-124.5. IR(KBr) 3207, 2933, 1743; NMR (d, CDCL 3 ) 0.6-2.4(20H, m, CH 2 , CH 3 ), 3.2-3.8 (1H, m, CHS), 4.0-4.8 4H, M, CHN, CH 2 --O), 6.8-7.0 (1H, m, NH). Analysis Calculated for C 15 H 26 O 2 N 2 S 2 : C, 54.51: H, 7.93; N, 8.48. Found C, 54.44; H, 7.80; N 8.62; and 752 mg (49%) of 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl; ethylester (1α,7β,7aα) which was crystallized from ether, MP 106°-107° C. IR (KBr) 3437, 2925, 1743; NMR (d, CDCl 3 ) 0.6- 2.3 (20H, m, CH 2 , CH 3 ), 3.0-3.6 (1H, m, CHS). 4.0-4.9 (4H, m, CHN, CH 2 O), 6.3-6.5 (1H, m, NH). Analysis Calculated for C 15 H 26 O 2 N 2 S 2 : C, 54.51; H, 7.93; N, 8.48. Found C, 54.23; H, 7.71; N, 8.63. EXAMPLE 3 3H, 5H-Imidazo [1, 5c]thiazole-1-pentanoic acid, tetrahydro-7-carboethoxy-3, 3-dimethyl-5-oxo, methyl ester, (1α,7α,7aα) and (1α,7β,7aα) To 2,2-Dimethyl-3-thiazole-5-pentanoic acid, methyl ester (5.77 g, 23 mmol) in dry tetrahydrofuran (50 ml) at 0° C. was added over a one minute period boron trifluoride etherate (2.82 ml, 23 mmol). The reaction mixture was allowed to warm to room temperature, stirred for one hour, and cooled to -78° C. To an addition funnel containing diisopropylamine (3.23 ml, 23 mmol) at room temperature in tetrahydrofuran (150 ml) was added 2.3M butyl lithium (10 ml, 23 mmol). The solution was stirred at room temperature for 15 minutes and then cooled to -78° C. To this solution was added all at once ethyl iscoyanatoacetate (2.97 g, 23 mmol) in tetrahydrofuran (10 ml). This solution was allowed to stir for 6 minutes and then added to the boron trifluoride-thiazoline solution. The resulting solution was stirred at -78° for 2 hours and allowed to warm to room temperature and stirred for about 20 minutes. The reaction mixture was concentrated, taken up in ethyl acetate and extracted with 0.5N hydrochloric acid solution. The aqueous layer was back extracted with ethyl acetate (3X). The organics were washed with brine, dried over magnesium sulfate, concentrated to afford 9.8 grams of crude product which was chromatographed on 330 grams of silica gel using methylene chloride: diethyl ether (3:2) to afford 3.05 g (37%) of a product mixture (1:1) containing 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-7-carboethoxy-3,3-dimethyl-5-oxo; methylester, (1α,7α,7aα) as an oil. IR(CHCl 3 ) 3444, 2926, 1726; NMR (d, CDCL 3 ) 1.1-2.1 (15H, m, CH 2 , CH 2 ), 2.2-2.6 (2H, m, CHCH 2 ), 3.3-3.6 (1H, m, CHS), 3.7(3H, s, OCH 3 ), 4.0-4.6 (4H, m, CHN, OCH 2 ), 5.1-5.3 (1H, m, NH). Analysis Calculated for C 16 H 26 O 5 N 2 S: C, 53.61; H, 7.31; N, 7.81; S, 8.94. Found: C, 53.32; H, 7.26; N, 8.06; S, 8.57; and 3H,5H-Imidazo[1,5c]-thiazole-1-pentanoic acid, tetrahydro-7-carboethoxy 3,3-dimethyl-5-oxo-methyl ester, (1α ,7β,7aα), mp 89°-90° C. IR(KBr) 3242, 2928, 1746, 1700; NMR (d, CDCL 3 ) 0.63-2.1 (15H, m, CH 2 , CH 3 ), 2.13-2.6 (2H, m, CHCH 2 ), 3.1-3.5 (1H, m, CHS) 3.7 (3H, s, OCH 3 ), 3.9-4.6 (4H, m, CHN, OCH 2 ); 4.9-5.2 (1H, m, NH). Analysis Calculated for C 16 H 26 O 5 N 2 S: C, 53.61; H, 7.31; N, 7.81; S, 8.94. Found: C, 53.81; H, 7.52; N, 7.75; S, 8.88. EXAMPLE 4 3H, 5H-Imidazo [1, 5c] thiazole-1-pentanoic acid, tetrahydro-7-carboethoxy-3,3-dimethyl-5-thioxo, methyl ester (1α,7α,7aα) and (1α,7β,7aα) To a dry tetrahydrofuran solution (100 ml) containing 2,2-dimethyl-3-thiazoline-5-pentanoic acid, methyl ester (11.17 g, 48.8 mmol) under a nitrogen atmosphere at -4° C. was added dropwise over a 2 minute period boron trifluoride etherate (6.00 ml, 48.78 mmol). Internal temperature did not rise abot 0° C. The reaction mixture was stirred at -4° to 0° C. for 15 minutes. The ice bath was removed and the reaction mixture was stirred for 45 minutes and then cooled to -75° C. Lithium t-butoxide (4.10 grams, 51.22 mmol) was dissolved in dry tetrahydrofuran (150 ml) and the solution was cooled to -75° C. Ethyl isothiocyanatoacetate (7.07 grams, 48.78 mmol) was dissolved in dry tetrahydrofuran (50 ml) in a cold jacketed addition funnel (-75° C.) and was added to the lithium t-butoxide solution over 6 to 7 minutes. Internal temperature did not exceed -71° C. The solution was stirred for 10 minutes following the addition. A polyethylene tube was put into the anion solution and nitrogen was used to push the anion into the imine/boron trifluoride solution. The addition occurred in less than one minute. The internal temperature of the final reaction mixture rose from -75° to -65°. The reaction mixture was stirred at -75° C. for 1.5 hours and then quenched with acetic acid (2.8 ml, 48.78 mmol) in tetrahydrofuran (5 ml). The brown reaction mixture became light orange. Organic solvents were removed in vacuo and the residue was taken up in 900 ml of ethyl acetate and washed with 5×200 ml of sodium bicarbonate solution followed by 1×200 ml of brine. The organic portion was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 18.22 grams of product. The crude product was purified by column chromatography on pH 9 buffered silica gel (eluant methylene chloride:ether, 98:2) to give 14.80 g (81%) of a product mixture (1:2.5) containing 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-7-carboethoxy-3,3-dimethyl-5-thioxo, methyl ester (1α,7α,7aα) which could be recrystallized from hexane to give a solid, mp 55°-55.5° C. IR(KBr) 3211, 2929, 1740; NMR (d, CDCL 3 ) 1.1-2.6 (17H, m, CH 2 CH 3 , CH 2 , CCH 3 ), 3.1-3.6 (1H, m, CHS), 3.7 (3H, S, OCH 3 ), 3.9-4.8 (4H, m, CHN, OCH 2 ), 6.5 (1H, m, NH). Analysis Calculated for C 16 H 26 N 2 O 4 S 2 : C, 51.34; H, 6.95; N, 7.49. Found C, 51.23; H, 6.86; N, 7.26; and 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-7-carboethoxy-3,3-dimethyl-5-thioxo-methyl ester (1α,7β,7aα) which was recrystallized from hexane to give a solid, mp 76°-78° C. IR(KBr) 3439, 3411, 2940, 1740; NMR (d, CDCl 3 ) 1.1-2.7 (17H, m, CH 2 CH 3 , CH 2 , CCH 3 ), 3.1-3.6 (1H, m, CHS), 3.7 (3H, s, OCH 3 ), 3.9-4.9 (4H, m, CHN, OCH 2 ), 5.9-6.3 (1H, m, NH). Analysis Calculated for C 16 H 26 N 2 O 4 S 2 : C, 51.34; N, 6.95; N, 7.49. Found: C, 51.09; H, 6.88; N, 7.52. EXAMPLE 5 3H,5H-Imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl,-,2,6-di-t-butyl-4-methylphenyl ester (1α,7α,7aα) and (1α,7β,7aα) A procedure identical to that of Example 2 involving 2,2-dimethyl-5-pentyl-3-thiazoline and 2,6-di-t-butyl-4-methylphenyl-2-isothiocyanatoacetate afforded a 1:5 mixture (˜90% yield) containing 3H5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl-2,6-di-t-butyl-4-methylphenyl ester (1α,7α,7aα), mp 87°-95° C. IR (KBr) 3189, 2958, 1762; NMR (d, CDCL 3 ) 0.6-1.7 (29H, m, C(CH 3 ) 3 , --CH 2 , CH 2 --CH 3 ), 1.9 (3H, s, CCH 3 ), 2.2 (3H, s, CCH 3 ), 2.3 (3H, s, phenyl methyl), 3.2-3.8 (1H, m, CHS), 4.3-4.9 (2H, m, CHN), 6.9 (1H, bs, NH), 7.1 (2H, bs, Ar--H). Analysis Calculated for C 28 H 44 N 2 O 2 S 2 : C, 66.62; H, 8.79; N, 5.55. Found: C, 66.60; H, 8.88; N, 5.52; and 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl-,2,6-di-t-butyl-4-methylphenyl ester (1α,7β,7aα), mp 149-151. IR (KBr) 3447, 3177, 2958, 2924, 1760; NMR (d, CDCL 3 ) 0.57-2.2 (35H, m, C(CH 3 ) 3 , --CH 2 , --CH 2 --CH 3 , C(CH 3 ) 2 ), 2.3 (3H, s, Ar--H), 3.6-4.2 (1H, m, CHS), 4.3-5.0 (2H, M, CHN), 6.3-6.6 (1H, m, NH), 7.1 (2H, bS, Ar--H). Analysis Calculated for C 28 H 44 N 2 O 2 S 2 : C, 66.62; H, 8.79; N, 5.55. Found: 66.56; H, 8.61; N, 5.60. EXAMPLE 6 3H,5H-Imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl,-ethyl ester (1α,7β,7aα). To a dry tetrahydrofuran solution (600 ml) containing 2,2-pentamethylene-5-pentyl-3-thiazoline (123 g, 0.548 mol) under a nitrogen atmosphere at -2° C. was added over a 10 minute period boron trifluoride etherate (67 ml, 0.548 mol). The reaction mixture was stirred at 0° for 15 minutes. The ice bath was removed, the reaction mixture was stirred for 45 minutes and was then cooled to -78° C. Lithium t-butoxide (48.5 g, 0.603 mol) was dissolved in dry tetrahydrofuran (800 ml) and the solution was cooled to -78° C. Ethyl isothiocyanatoacetate (87.5 g, 0.603 mol) was dissolved in dry tetrahydrofuran (250 ml) in a cold jacketed addition funnel (-78° C.) and was then added to the lithium t-butoxide solution over a 7 to 8 minute period. The internal temperature did not exceed -68° C. The solution was stirred for an additional 17 minutes at which time a polyethylene tube was used with positive nitrogen pressure to push the anion and the imine/boron trifluoride (-78° C.) solution. The addition occurred in about 3 minutes. The internal temperature rose from -78° to -55° C. The reaction mixture was stirred at -78° C. for 1.75 hour. and was then quenched with acetic acid (36 ml, 0.603 mol) in tetrahydrofuran (40 ml). The reaction mixture was concentrated in vacuo and the residue was taken up in ethyl acetate (3.25 liters) and washed with a 1:1 mixture of aqueous brine and saturated sodium bicarbonate (2 liters) followed by aqueous brine (1 liter). The organic portion was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 212 g of oily solids. A hexane:ether (12:1) trituration afforded 88.1 g of mainly 3H,5H[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl,-methyl ester (1α,7β,7aα). An additional 18.7 g was obtained by additional trituration of the mother liquor. An analytical sample, mp 121°-122° C. was obtained after carbon tetrachloride recrystallization. IR(KBr) 3429, 2930, 1741. NMR (d, CDCl 3 ) 0.8-2.2 (22H, m, CH 2 , CH 3 ) 2.8-3.8 (3H, m, CHS, CCH 2 ), 4.1-4.9 (4H, m, OCH 2 , CHN), 6.5 (1H, bS, NH) Analysis Calculated for C 18 H 30 N 2 O 2 S 2 : C, 58.38; H, 8.11; N, 7.57. Found C, 58.18; H, 7.98; N, 7.74. EXAMPLE 7 3H,5H-Imidazo[1,5c]thiazole-pentanoic acid, tetrahydro-7-carboethoxy-3,3-pentamethylene-5-thioxo, ethylester, (1α,7β,7aα). To a dry tetrahydrofuran solution (40 ml) containing 2,2-pentamethylene-3-thiazoline-5-pentanoic acid, methyl ester (10.12 g, 37.6 mmol) under a nitrogen atmosphere at -10° C. was added over a 5 minute period boron trifluoride etherate (4.63 ml, 13.6 mmol). The reaction mixture was stirred at 0° for 15 minutes. The ice bath was removed, the reaction mixture was stirred for 45 minutes and was then cooled to -78° C. Lithium t-butoxide (3.31 g, 41.4 mmol) was dissolved in dry tetrahydrofuran (50-75 ml) and the solution was cooled to -78° C. Ethy isothiocyanatoacetate (6.0 g, 41.4 mmol) was dissolved in dry tetrahydrofuran (240 ml) in a cold jacketed addition funnel (-78° C.) and was then added to the lithium t-butoxide solution over a 10 minute period. The internal temperature did not exceed -68° C. The solution was stirred for an additional 15 minutes at which time a polyethylene tube was used with positive nitrogen pressure to push the anion into the imine/boron trifluoride (-78° C.) solution. The addition including the washes occurred in about 3 minutes. The reaction mixture was stirred at -78° C. for 1.75 hour and was then quenched with acetic acid (2.5 ml, 41.4 mmol) in tetrahydrofuran (2 ml). The reaction mixture was concentrated in vacuo and the residue was taken up in ethyl acetate (250 ml) and washed with a 1:1 mixture of aqueous brine and saturated sodium bicarbonate (150 ml) followed by aqueous brine (75 ml). The organic portion was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 15.6 g of a reddish brown oil which was triturated several times with a hexane:ether (10:1) solution to afford 8 g of mainly 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-7-carboethoxy-3,3-pentamethylene-5-thioxo, ethyl ester (1α,7β,7aα). An analytical sample, mp 84°-87° was obtained from a carbon tetrachloride recrystallization. IR (KBr) 3434, 2930, 1740, 1446, 1417 NMR (d, CDCl 3 ) 1.05-2.2 (19H, m, CH 2 , C--CH 3 ), 2.2-2.6 (2H, m, CH 2 ), 3.2-3.6 (1H, m, CHS), 3.8 (3H, s, OCH 3 ), 4.2-5.0 (4H, m, CHN, OCH 2 ), 6.2-6.35 (1H, bs, NH). EXAMPLE 8 3H,5H-Imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl;-methoxyethyl ester (1α,7α,7aα) and (1α,7β,7aα). A procedure identical to that of Example 2 involving 2,2-dimethyl-5-pentyl-3-thiazoline and methoxyethyl isothiocyanatoacetate afforded after a pH 9 silica gel chromatography (eluant 98:2 methylene chloride:ether) a 1:2.9 mixture (85%) containg 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl; methoxyethyl ester (1α,7α,7aα), mp 69°-70° C. IR (KBr) 3437, 2926, 1756. NMR (d, CDCL 3 ) 0.6-2.2 (17H, m, CH 2 , CCH 3 ), 3.2-3.8 (6H, m, CHS, OCH 2 , OCH 3 ) 4.1-4.8 (4H, m, CHN, OCH 2 ), 6.6-6.8 (1H, bs, NH). Analysis Calculated for C 16 H 28 N 2 S 2 O 3 : C, 53.30; H, 7.83; N, 7.77. Found: C, 53.18; H, 7.56; N, 7.83; and 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro- 3,3-dimethyl-5-thioxo-1-pentyl, methoxyethyl ester (1α,7β,7aα), mp 75°-77°. IR (KBr) 3437, 2926, 1756; NMR (d, CDCl 3 ) 0.6-2.4 (17H, m, CH 2 , CCH 3 ) 3.0-3.8 (6H, m, CHS, OCH 2 , OCH 3 ), 4.1-5.0 (4H, m, CHN, OCH 2 ), 6.7-7.0 (1H, bS, NH). Analysis calculated for C 16 H 28 N 2 S 2 O 3 : C, 53.30; H, 7.83; N, 7.77. Found: C, 53.08; H, 7.70; N, 7.87. EXAMPLE 9 3H,5H-Imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl, n-propyl ester, (1α,7α,7aα) and (1α,7β,7aα). A procedure identical to that of Example 2 involving 2,2-dimethyl-5-pentyl-3-thiazoline and n-propyl isothiocyanatoacetate afforded after pH 9 silica gel chromatography (eluant 95:5 methylene chloride:ether) a 1:3 mixture (83% yield) containing 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl; n-propyl ester (1α,7α,7aα), mp 55°-56° C. IR (KBr) 3278, 2928, 1744; NMR (d, CDCL 3 ) 0.7-2.3 (22H, m, CH 2 , CCH 3 , CH 2 CH 3 ), 3.2-3.7 (1H, m, CHS), 4.0-4.8 (4H, m, CHN, OCH 2 ), 6.5 (1H, bs, NH). Analysis calculated for C 16 H 28 N 2 S 2 O 2 : C, 55.78; H, 8.19, N, 8.13. Found C, 55.81; H, 8.03; N, 8.06. and 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3 -dimethyl-5-thioxo-1-pentyl; n-propyl ester (1α,7β,7aα), mp 64°-66° C., IR (KBr) 3438, 2926, 1739; NMR (d, CDCL 3 ) 0.7-2.3 (22H, m, CH 2 , CCH 3 , CH 2 CH 3 ), 3.1-3.5 (1H, m CHS), 4.0-4.9 (4H, m, CHN, OCH 2 ), 6.6 (1H, bs, NH) Analysis calculated for C 16 H 28 N 2 S 2 O 2 : C, 55.78; H, 8.19; N, 8.13 Found C, 55.71; H, 7.96; N, 8.08. EXAMPLE 10 3H, 5H-Imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl; isopropyl ester, (1α,7α,7aα) and (1α,7β,7aα). A procedure identical to that of Example 2 including 2,2-dimethyl-5-pentyl-3-thiazoline and i-propyl-2-isothiocyanatoacetate afforded a 1:3 mixture (81% yield) containg 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl-, i-propyl ester (1α,7α,7aα), mp 103°-104° C. Ir (KBr) 3210, 2956, 1737 NMR (d, CDCL 3 ) 0.6-2.5 (23H, m, CH 2 , CH 3 ) 3.2-3.7 (1H, m, CHS), 4.0-5.4 (3H, m, CHN, CHO), 6.5-6.9 (1H, bs, NH). Analysis Calculated for C 16 H 28 N 2 O 2 S 2 : C, 55.78; H, 8.19; N, 8.13. Found: C, 56.01; 8.08; N, 8.15; and 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl, i-propyl ester (1α,7β,7aα), mp 46°-49° C. IR (KBr) 3245, 2977, 2557, 1737. NMR (d, CDCl 3 ) 0.7-2.3 (23H, m, CH 2 , CH 3 ), 3.1-3.6 (1H, m, CHS), 4.2 (1H, d, J=10 Hz, CHO), 4.5-5.4 (2H, m, CHN), 6.7 (1H, bs, NH), Analysis Calculated for C 16 H 28 N 2 O 2 S 2 : C, 55.78; H, 8.19; N, 8.13. Found: C, 55.61; H, 7.90; N, 7.97. EXAMPLE 11 3H,5H-Imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl, 2-methyl-6-t-butylphenyl ester (1α,7α,7aα) and (1α,7β,7aα). A procedure identical to that of Example 2 involving 2,2-dimethyl-5-pentyl-3-thiazoline and 2-methyl-6-t-butylphenyl-2-isothiocyanatoacetate afforded a 1:3 mixture (90% yield) containing 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl-, 2-methyl-6-t-butylphenyl ester (1α,7α,7aα), mp 136°-138° C. IR (KBr) 3193, 2928, 1753: NMR (d, CDCL 3 ) 0.6-1.7 (20H, m, CH 2 CH 2 CH 3 , C(CH 3 ) 3 ) 1.9 (3H, s, C--CH 3 ), 2.13 (3H, s, Ar--CH 3 ), 2.2 (3H, s, C--CH 3 ), 3.3-3.8 (1H, m, CHS), 4.4-5.0 (2H, m, CHN), 6.9 (1H, bs, NH), 7.1-7.4 (3H, m, Ar--H), Analysis Calculated for C 24 H 36 N 2 O 2 S 2 : C, 64.25; H, 8.09; N, 6.24. Found: C, 64.27, H, 7.93, N, 6.41; and 3H,5H-imidazol[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl-, 2-methyl-6-t-butylphenyl ester (1α, 7β,7aα), mp 142°-144° C. IR (KBr) 3217, 2925, 1745; NMR (d, CDCl 3 ) 0.7-1.8 (20H, m, CH 2 , CH 2 CH 3 , C(CH 3 ) 3 ), 1.95 (3H, s, C--CH 3 ), 2.1 (3H, s, C--CH 3 ) 2.15 (3H, s, Ar--CH 3 ), 3.6-4.2 (1H, m, CHS), 4.3-4.9 (2H, m, CHN), 6.5 (1H, bs, NH), 7.0-7.4 (3H, m, Ar--H). Analysis Calculated for C 24 H 36 N 2 O 2 S 2 : C, 64.25; H, 8.09; N, 6.24. Found: C, 64.04; H, 7.93; N, 6.10. EXAMPLE 12 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl (1α,7β,7aα). To a tetrahydrofuran solution (30 ml) containing 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl, ethyl ester (1α,7β,7aα) (2.0 g, 5.4 mmol) at 0° C. was added 2N sodium hydroxide (3.1 ml, 6.2 mmol). The solution was stirred at 0° for 1 hour and allowed to stir at room temperature for 17 hours. Acetic acid (355 ml, 6.21 mol) was then added, the solution was concentrated in vacuo and dissolved in ethyl acetate (100 ml). The organic solution was extracted with 1N HCL (2×30 ml) and the aqueous solutions were back washed with ethyl acetate. The combined organic extracts were dried over magnesium sulfate, filtered and concentrated to afford 1.83 g (100%) of 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl (1α,7β,7aα), NMR (d, CDCl 3 0.62- 2.3 (19H, m, CH 2 , CH 3 ), 2.6-3.65 (3H, m, CHS, CCH 2 ), 4.05-4.85 (2H, m, CHN), 7.3 (1H, bs, NH), 10.65 (1H, bs, OH). EXAMPLE 13 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl, methyl ester IS (1α,7β,7aα). To an ether solution (20 ml) containing 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl (1α,7β,7aα) (761 mg, 2.22 mol) at 0° C. was added 99% d-ephedrine (371 mg, 2.22 mol). The solution was stirred for 12 hours at 0° C. and filtered. The solids were washed with ether, dried and recrystallized from benzene. The recrystallized salt was then placed in a methanol solution (30 ml) saturated with hydrochloric acid (0° C.) and stirred for 3 hours. The resultant solution was concentrated in vacuo, dissolved in ethyl acetate (50 ml) and washed with 2N hydrochloric acid (2×30 ml), dilute sodium bicarbonate (1×30 ml) followed by brine (1×30 ml) and dried over magnesium sulfate. The organic solution was filtered and concentrated in vacuo to afford 346 mg (61%) of 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl, methyl ester IS (1α,7β,7aα) NMR (d, CDCl 3 ) 0.7-2.4 (19H, m, CH 2 , CH 3 ) 2.6-3.6 (3H, m, CHS, C--CH 2 ) 3.78 (3H, S, OCH 3 ). 4.0-4.9 (2H, m, CHN), 6.85 (1H, bs, NH). EXAMPLE 14 3H,5H-imidazo[1,5c]thiazole, tetrahydro-3,3-pentamethylene-7-hydroxymethyl-5-thioxo-1-pentyl 1S (1α,7β,7aα). To a 1:1 tetrahydrofuran:methanol solution (8 ml) containing 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-pentamethylene-5-thioxo-1-pentyl, methyl ester 1S (1α,7β,7aα) (657 mg, 1.85 mmol) was added sodium borohydride (274 mg, 7.4 mol). The solution was stirred at 0° C. for 1.5 hour, at room temperature for 1.5 hour and concentrated under reduced pressure. Ethyl acetate (75 ml) was added to the residue and the organic solution was extracted with 0.5N HCL (1×40 ml) and a 1:1 brine: sodium bicarbonate solution (1×40 ml). The organic layer was dried over magnesium sulfate; filtered and concentrated in vacuo to afford 580 mg (100%) of 3H,5H-imidazo[1,5c]thiazole, tetrahydro-3,3-pentamethylene-7-hydroxymethyl-5-thioxo-1-pentyl IS (1α,7β,7aα). NMR (d, CDCl 3 ) 0.6-2.2 (19H, m, CH 2 , CH 3 ), 2.7-4.7 (7H, m, CH 2 --O, CHN, CHS, OH, C--CH 2 ), 7.05 (1H, bs, NH). EXAMPLE 15 3H,5H-Imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-3,3-dimethyl-7-hydroxymethyl-5-thioxo, methyl ester, (1α,7β,7aα). To a methanol solution (150 ml) containing 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-7-carboethoxy-3,3-dimethyl-5-thioxo, methyl ester (1α,7β,7aα) (5.64 g, 15.08 mmol) at 0° C. was added sodium borohydride (2.28 g, 60.32 mmol). The solution was stirred at 0° C. for 1.75 hour, and allowed to warm to room temperature (45 minutes). The reaction mixture was concentrated in vacuo and taken up in ethyl acetate (300 ml). The organic solution was extracted with 0.2N HCL (70 ml) and a brine solution (70 ml), dried over magnesium sulfate, filtered and concentrated in vacuo to afford 5.0 g (99%) of 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-3,3-dimethyl-7-hydroxymethyl-5-thioxo, methyl ester (1α,7β,7aα). An analytical sample, mp 103°-105°, was prepared by an ether recrystallization. IR (KBr) 3411, 3199, 2927, 1731. NMR (d, CDCL 3 ) 0.7-2.6 (14H, m, CH 2 ), 3.66 (3H, s, OCH 3 ), 2.9-4.9 (6H, m, CHN, CHS, CH 2 --O, OH), 6.8-7.1 (1H, bs NH). Analysis Calculated for C 14 H 24 N 2 O 3 S 2 : C, 50.60; H, 7.23; N, 8.43. Found: C, 50.36; H, 7.08; N, 8.49. EXAMPLE 16 3H,5H-Imidazo[1,5c]thiazole, tetrahydro-3,3-dimethyl-7-hydroxymethyl-5-thioxo-1-pentyl, (1α,7β,7aα) 3H,5H-Imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-thioxo-1-pentyl-, ethyl ester (1α,7β,7aα) (572 mg, 1.73 mol) was dissolved in methanol (15 ml) and cooled to 0° C. Sodium borohydride (262 mg, 6.93 mol) was added and the solution was stirred at 0° for 1.75 hr and allowed to come to room temperature. The reaction mixture was concentrated in vacuo and taken up in ethyl acetate (75 ml). The organic solution was extracted with 0.5N HCL (1×40 ml) and a 1:1 brine:sodium bicarbonate solution (1×80 ml). The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 486 mg (97%) of 3H,5H-Imidazo[1,5c]thiazole, tetrahydro-3,3-dimethyl-7-hydroxymethyl-5-thioxo-1-pentyl (1α,7β,7aα). An analytical sample, mp 112°-114° C. was obtained following a methanol recrystallization. IR (KBr) 3351, 2925; NMR (d, CDCL 3 ) 0.4-2.5 (17H, m, C--CH 2 , CH 3 ), 3.2-4.8 (6H, m, CHS, CHN, CH 2 O, OH), 6.9-7.2 (1H, m, NH) Analysis Calculated for C 13 H 24 N 2 OS 2 : C, 54.17; H, 8.33; N, 9.72. Found: C, 54.26; H, 8.07; N, 9.55. EXAMPLE 17 3H,5H-Imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-3,3-dimethyl-7-[[(methylsulfonyl)oxy]methyl]-5-oxo, methyl ester, (1α,7β,7aα). To a methylene chloride solution (10 ml) containing 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-3,3-dimethyl-7-hydroxymethyl-5-oxo, methyl ester (1α,7β,7aα). (220 mg, 0.695 mmol) at 0° C. was added triethylamine (200 μl, 1.42 mol, followed by methanesulfonyl chloride (621 μl, 0.775 mmol). The solution was allowed to warm to room temperature and stirred for 1 hour. Additional methylene chloride (50 ml) was added and the organic solution was extracted with H 2 O (1×30 ml), 0.5N HCL (1×20 ml), 5% sodium bicarbonate (1×20 ml) and brine (1×20 ml) The aqueous layers were backwashed with methylene chloride and the organic extracts were dried over magnesium sulfate, filtered and concentrated in vacuo to give 263 mg (96%) of 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-3,3-dimethyl-7-[[(methylsulfonyl)oxy]methyl]-5-oxo, methyl ester (1α,7β,7aα). An analytical sample, mp 118.5°-119.5° C. was obtained following an ether recrystallization. IR (KBr) 3305, 1732, 1711. NMR (d, CDCL 3 ) 1.0-2.0 (12H, m, C--CH 2 , C(CH 3 ) 2 ), 2.1-2.5 (2H, t, ##STR13## 3.1 (3H, s, ##STR14## 3.4-4.6 (8H, m, OCH 3 , CH 2 --O, CHN, CHS), 5.6-5.9 (1H, m, NH). Analysis Calculated for C 15 H 26 N 2 O 6 S 2 : C, 45.68; H, 6.60; N, 7.11 Found: C, 45.90; H, 6.45; N, 7.08. EXAMPLE 18 3H,5H-Imidazo[1,5c]thiazole, tetrahydro-3,3-pentamethylene-7-[[(d-camphorsulfonyl)oxy]methyl]-5-thioxo-1-pentyl 1S (1α,7β,7aα) To a methylene chloride solution (100 ml) containing 3H,5H-imidazo[1,5c]thiazole, tetrahydro-3,3-pentamethylene-7-hydroxymethyl-5-thioxo-1-pentyl (1α,7β,7aα) (3.78 g, 11.5 mmol) at 0° C. was added triethylamine (1.61 ml, 11.5 mol) followed by d-10-camphorsulfonyl chloride (2.89 g, 11.5 mmol) in methylene chloride (25 ml). The reaction mixture was stirred for 2 hr at 0° C. Additional methylene chloride (400 ml) was added and the reaction mixture was washed with brine (1×100 ml), dried over magnesium sulfate, filtered and concentrated in vacuo to afford a solid which was chromatographed on 500 g of 48-63μ silica gel using ether:methylene chloride (4:96). A total of 4.46 g (71%) of diasteriometric products was obtained. The first isomer (2.23 g) was 3H,5Himidazo[1,5c]thiazole, tetrahydro-3,3-pentamethylene-7-[[(d-camphorsulfonyl)oxy]methyl]-5-thioxo-1-pentyl 1S (1α,7β,7aα) .sup.α D=+14.9 C=0.01, (methanol). NMR (d, CDCL 3 ) 0.8 (3H, s, CCH 3 ), 1.0 (3H, s, CCH 3 ), 0.8-2.5 (28H, m, CH 2 , C--CH, CH 2 CH 3 ), 3.25 (2H, q CH 2 SO 2 ), 3.0-3.7 (1H, m, CHS), 3.7-4.7 (4H, m, CHN, CH 2 --O), 6.28 (1H, bs, NH). EXAMPLE 19 Dl-Biotin, methyl ester To a trifluoroacetic acid solution (10 ml) containing 3H,5H-imidazo[1,5c]thiazole-1-pentanoic acid, tetrahydro-3,3-dimethyl-7-[[(methylsulfonyl)oxy]methyl]-5-oxo, methyl ester (1α,7β,7aα) (263 mg, 0.67 mmol) was added deuterium oxide (0.6 ml). The solution was heated at 45° C. for 5 hours (reaction was monitored by NMR) and then concentrated in vacuo. The crude reaction mixture was dissolved in methylene chloride (200 ml) and extracted with dilute sodium bicarbonate (1×50 ml) followed by brine (1×50 ml). The aqueous extracts were back extracted with methylene chloride (100 ml) and the combined orange extracts were dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 183 mg of crude solid which was triturated with ether and recrystallized from ethyl acetate to give 78 mg (43%) of dl-biotin methyl ester, mp 127°-129° C. IR (KBr) 3225, 2941, 1751, 1718. NMR (d, DMSO) 1.15-1.95 (6H, m, CH 2 ), 2.35 (2H, t, CH 2 --CO), 2.60-3.06 (2H, m, CH 2 S) 3.08-3.30 (1H, m, CHS), 3.65 (3H, s, OCH 3 ), 4.15-4.64 (2H, m, CHN), 5.90 (1H, bs, NH), 6.13 (1H, bs, NH) Analysis Calculated for C 11 H 18 N 2 O 3 S: C, 51.16; H, 6.98; N, 10.85. Found: C, 51.17; H, 7.01; N, 10.85. Mass Spectrum: Calculated (258.1038), observed (258.1041). EXAMPLE 20 1-H-Thieno[3,4-d]imidazole-4-pentanoic acid, hexahydro-2-thioxo (3aα,4β,6aα) (dl-thioxobiotin) A trifluoroacetic acid solution (2 ml) containing 3H,5H-imidazo[1,5-c]thiazole, tetrahydro-3,3-pentamethylene-7-hydroxymethyl-5-thioxo-1-pentyl (1α,7β,7aα) (302 mg, 0.812 mmol) and water (0.86 ml) was heated under reflux for 1.5 hours and then cooled to 50° C. and concentrated in vacuo. Ethanol (5 ml) was added and the solution was again concentrated under reduced pressure. The solid residue was triturated with diisopropylether and then ethyl acetate to afford 134 mg (64%) of 1-H-thieno[3,4-d]imidazole-4-pentanoic acid, hexahydro-2-thioxo (3aα,4β,6aα) (dl-thioxobiotin) mp>250°. IR (KBr) 3407, 3291, 2939, 1694. NMR (d, DMSO) 1.22-1.77 (6H, m, CH 2 ), 2.33 (2H, t, J=8 HZ, CH 2 --CO), 2.68 (1H, d, J=12 Hz, CH 2 S), 2.90 (1H, q, J AB = 12 HZ, Jax=6 HZ, CH 2 S), 3.15-3.25 (1H, m, CHS), 4.35-4.50 (1H, m, CHN) 4.53-4.64(1H, m, CHN), 8.21 (1H, bs, NH), 8.31 (1H, bs, NH). Analysis Calculated for C 10 H 16 N 2 O 2 S 2 : C, 46.15; H, 6.15; N, 10.77, Found: C, 46.52; H, 6.19; N, 10.48. EXAMPLE 21 1-H-Thieno[3,4-d]imidazole-hexahydro-2-thioxo-4-pentyl; 3aS (3aα,4β,6aα) 3H,5H imidazo[1,5c]thiazole, tetrahydro-3,3-pentamethylene-7-[[(d-camphorsulfonyl)oxy]methyl]-5-thioxo-1-pentyl IS(1α,7β,7aα) (761 mg, 1.40 mmol) was dissolved in trifluoroacetic acid (5 ml). Water (1 ml) was added and the solution was kept at 45° for about 17 hours. The reaction mixture was concentrated in vacuo. The white solid residue was dissolved in boiling ethyl acetate (500 ml), aqueous sodium bicarbonate (100 ml) was added and the hot two phase system was separated. The organic portion was dried over magnesium sulfate, filtered and concentrated in vacuo to afford, after a methanol trituration, 187 mg (58%) of 1-H-thieno[3,4d]imidazolehexahydro-2-thioxo-4-pentyl 3aS (3aα,4β,6aα), mp 262°-262.5° C.; α D =+133° (C=0.01, TFA); IR (KBr) 3220, 2919; NMR (d, DMSO) 0.68-1.04 (3H, m, CH 2 CH 3 ), 1.08-1.96 (8H, m, C--CH 2 ), 2.64-2.98 (2H, m, CH 2 S), 3.05-3.36 (1H, m, CHS), 4.28-4.46 (1H, m, CHN), 4.47-4.70 (1H, m, CHN), 8.14 (1H, bs, NH), 8.22 (1H, bs, NH). Analysis calculated for C 10 H 18 N 2 S 2 : C, 52.17; H, 7.83; N, 12.17. Found C, 51.93; H, 7.44; N, 12.09. EXAMPLE 22 1H-Thieno[3,4-d]imidazole-hexahydro-2-thioxo-4-pentyl; 3aS (3aα,4β,6aα). 3H,5H-imidazo[1,5-c]thiazole, tetrahydro-3,3-pentamethylene-7-hydroxymethyl-5-thioxo-1-pentyl 1S (1α,7β,7aα) (580 mg, 1.77 mmol) was dissolved in trifluoroacetic acid (4.6 ml) and water (1.2 ml) and the resultant solution was heated at 100°-105° C. for 4 hours. The reaction mixture was cooled to 50° C. and concentrated in vacuo. Ethanol (6.0 ml) was added and the solution was again concentrated under reduced pressure. The white residue was triturated with ethyl acetate to afford 267 mg (66%) of 1H-thieno[3,4-d]imidazole-hexahydro-2-thioxo-4-pentyl, 3aS (3aα,4β,6aα), mp 262°-262.5 α D 25 ° C. =133° (C=0.01, TFA); IR (KBr) 3220, 2919; NMR (d, DMSO) 0.68-1.04 (3H, m, CH 2 CH 3 ), 1.08-1.96 (8H, m, C--CH 2 ), 2.64-2.98 (2H, m, CH 2 S), 3.06-3.36 (1H, m, CHS), 4.28-4.46 (1H, m, CHN), 4.47-4.70 (1H, m, CHN), 8.14 (1H, bs, NH), 8.22 (1H, bs, NH). EXAMPLE 23 1-H-Thieno[3,4-d]imidazole-hexahydro-2-oxo-4-pentyl; (3aα,4β,6aα). To an ethanol solution (14 ml) containing 1-H-thieno[3,4-d]imidazole-hexahydro-2-thioxo-4-pentyl (3aα,4β,6aα) (307 mg, 1.33 mmol) was added bromoethanol (208 ml, 2.93 mol). The solution was heated under reflux for 20 hours. Aqueous saturated sodium carbonate (1.5 ml) was added and the reaction was heated for an additional 10 minutes, cooled, and concentrated in vacuo to give a solid residue which was dissolved in ethyl acetate (100 ml) and shaken with brine (2×35 ml). The organic extract was dried over magnesium sulfate, filtered and concentrated in vacuo to afford white solids which were recrystallized from ethyl acetate to give 196 mg (69%) of 1-H-thieno[3,4-d]imidazole-hexahydro-2-oxo-4-pentyl (3aα,4β,6aα) mp 144°-145° C. IR(KBr) 3175, 2899, 1709; NMR (d, DMSO) 0.69-1.10 (3H, m, CH 3 ), 1.11-1.86 (8H, m, CH 2 ), 2.44-2.96 (2H, m, CH 2 --S), 2.98-3.24 (1H, m, CHS), 4.02-4.21 (1H, m, CHN), 4.30-4.44 (1H, m, CHN), 6.36 (1H, bs, NH), 6.58 (1H, bs, NH); Mass spectrum: Calculated 214.1140, Observed: 214.1144. Analysis Calculated for C 10 H 18 N 2 OS: C, 56.08; H, 8.41; N, 13.08. Found C, 56.00; H, 8.07; N, 12.71. EXAMPLE 24 (dl-Biotin) A diglyme solution (3 ml) containing dl-thioxobiotin (255 mg, 0.981 mol) and bromoethanol (140 μl, 1.98 mmol) was allowed to reflux (150°) for 2.5 hours. The solution was cooled, dilute sodium carbonate (50 ml) was added, and the solution was extracted with hexane (50 ml). The pH of the aqueous phase was adjusted to 1.5 with 6N HCL and extracted with ethyl acetate (4×100 ml). The ethyl acetate extract was dried over magnesium sulfate, filtered and concentrated in vacuo to give 148 mg (62%) of crude biotin, mp 220°-223° C. which was recrystallized from water IR (KBr) 3279, 2899, 1724; NMR (d, DMSO) 0.76-1.95 (6H, m, C--CH 2 ), 2.00-2.40 (2H, t, CH 2 --CO), 2.70-2.98 (1H, m, CH 2 S) 3.00-3.54 (2H, m, CH 2 S, CHS) 4.00-4.44 (2H, m, CHN), 6.44 (1H, bs, NH), 6.55 (1H, bs, NH), 11.8-12.4 (1H, bs, OH). Analysis calculated for C 10 H 16 O 3 N 2 S: C, 49.18; H, 6.56; N, 11.48; Found: C, 49.30; H, 6.23; N, 11.37. Mass spectrum: calculated: 244.0880, found: 244.0925. EXAMPLE 25 2,2-Dimethyl-5-pentyl-3-thiazoline The procedure of M. Thiel, F. Asinger, K. Schmiedel, (Liebigs Ann. Chem. 611, 121 (1958)) was employed. To a methanol solution (3 liters) containing sodium methoxide (216.7 g, 4.01 mole) at -10° C. was added hydrogen sulfide (˜1 lb) until the solution was saturated. To this solution was added dropwise over a 2 hour period 2-bromoheptaldehyde (775 g, 4.01 mol). The temperature of the reaction was maintained at about -10° C. after the addition, acetone (734 g, 12.6 mole) was added over a 10 minute period and the solution was stirred for an additional 20 minutes at about -10° C. at which time ammonia was added over a period of 1.5 hours. The solution was then poured into water (4 liters) and extracted with ether (4×1 liter). The combined etheral extracts were washed with brine (1×1 liter), dried over magnesium suflate and concentrated in vacuo to afford after distillation (70°-80°/1.5 mm) 549 g (74%) of 2,2-dimethyl-5-pentyl-3-thiazoline; NMR (d, CDCl 3 ) 0.6-2.2 (11H, m, CH 2 , CH 3 ) 1.70 (6H, s, C(CH 3 ) 2 ), 4.3-4.65 (1H, m, CHS), 7.10 (1H, d, CHN). EXAMPLE 26 3-Thiazoline-5-pentanoic acid, 2,2-dimethyl, methyl ester. The procedure of M. Thiel, F. Asinger, K. Schmiedel, (Liebigs Ann. Chem. 611, 121 (1958)) was employed. A sodium methoxide solution was prepared by adding sodium (736 mg, 32 mmol) to methanol (30 ml) under a nitrogen atmosphere. This solution was cooled at -10° C. and saturated with hydrogen sulfide (˜20 minutes). To this solution was added dropwise over a 15 minute period 5-bromo-6-formylhexanoic acid, methyl ester (7.49 g, 32 mmol). The reaction temperature was kept below -10° C. This solution was stirred for an additional 5 minutes at -10° C. at which time acetone (8 ml), was added. The reaction was stirred at -10° for 10 minutes at which time ammonia was introduced. The reaction temperature was not allowed to exceed 25° C. The reaction mixture became clear and ammonia was bubbled into the solution for about 40 minutes. Water (100 ml) was then added and this solution was extracted with ether (4×100 ml). The organic layer was dried over magnesium sulfate, filtered, and concentrated in vacuo to afford, after distillation (116°-125°/0.25 mm) 6.19 g (85%) of 3-thiazoline-5-pentanoic acid, 2,2-dimethyl, methyl ester. IR (CHCL 3 ) 2944, 1734 1648. NMR (d, CDCL 3 ) 1.2-2.1 (12H, m, C--CH 2 , C(CH 3 ) 2 ), 2.2-2.5 (2H, m, CH 2 CO), 3.7 (3H, s, OCH 3 ), 4.2-4.7 (1H, m, CHS), 7.0-7.2 (1H, m, CHN). EXAMPLE 27 2,2-pentamethylene-5-pentyl-3-thiazoline The procedure of M. Thiel, F. Asinger, K. Schmiedel, (Liebigs Ann. Chem. 611, 121 (1958)) was employed. To a methanol solution (75 ml) containing sodium hydrogen sulfide-water (6.25 g, 67.9 mmol) at -10° to 15° C. was added over a 15 minute period a methanol solution (15 ml) containing 2-bromoheptaldehyde (13.1 g, 67.9 mol). The temperation of the reaction mixture was maintained at about -10° C. After stirring for 15 minutes, cyclohexanone (21.1 ml, 204 mmol) was added over a period of 2 minutes. This solution was stirred for an additional 15 minutes at -10° C. at which time ammonia was introduced. Ammonia was added over a one hour period and the reaction mixture was allowed to warm to room temperature. The clear solution was poured into water (250 ml) and extracted with ether (3×200 ml). The organic extract was dried over magnesium sulfate, concentrated in vacuo and distilled (115°-125°/0.15 mm) to afford 10 g (66%) of 2,2-pentamethylene-5-pentyl-3-thiazoline. IR (CHCl 3 ) 2900, 2830, 1648, 1530; NMR (d, CDCL 3 ) 0.68-2.9 (21H, m, CH 2 , CH 3 ), 4.15-4.50 (1H, m, CHS), 7.2 (1H, d, CHN). EXAMPLE 28 1H-Thieno[3,4-d]imidazole-hexahydro-2-oxo, (3aα, 4β, 6aα). To a methanol solution (20 ml) containing 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-oxo-1-pentyl, ethyl ester (1α,7β,7aα) (358 mg, 1.14 mol) was added potassium hydroxide (75 mg, 1.14 mmol) in water (20 ml). The solution was stirred for 3 hours at room temperature, concentrated in vacuo, dissolved in ethyl acetate (200 ml) and extracted with 6N HCL (50 ml). The organic extract was dried over magnesium sulfate, filtered and concentrated under reduced pressure to give 330 mg of crude 3H,5H-imidazo[1,5c]thiazole 7-carboxylic acid, tetrahydro-3,3-dimethyl-5-oxo-1-pentyl (1α,7β,7aα). IR (KBr), 3359, 2927, 1733; NMR (d, DMSO) 0.7-2.3 (17H, m, CH 2 , CH 3 ), 3.0-4.7 (3H, m, CHN, CHS), 6.7-7.03 (1H, m, NH). This acid was dissolved in trifluoroacetic acid (10 ml), deuterium oxide (0.6 ml) was added and the solution was heated at 45° C. for 15 hours. The reaction mixture was concentrated in vacuo, taken up in ethyl acetate (200 ml) washed with water (2×50 ml), dried over magnesium sulfate, filtered, concentrated in vacuo, and precipitated with 1:1 methylene chloride: ether to afford 125 mg of crude 1H-thieno[3,4-d]imidazole-2,4-dione, tetrahydro-6-pentyl, (3aα,6β,6aα). An analytical sample, mp 247-247.5 was obtained after a hexane-methylene chloride recrystallization. IR (KBr) 3333, 2899, 1695. NMR (d, CDCL 3 ) 0.62-1.02 (3H, m, CH 3 ), 1.11-2.02 (8H, m, CH 2 ), 3.92-4.53 (3H, m, CH), 6.66-6.90 (1H, m, NH), 7.30-7.56 (1H, m, NH). Analysis Calculated for C 10 H 16 N 2 O 2 S: C, 52.63; H, 7.02; N, 12.28. Found: C, 52.30; H, 7.00; N, 12.28. This lactone (174 mg, 0.76 mmol) was dissolved in methanol (15 ml) at 0° C. Sodium borohydride (114 mg, 3.05 mmol) was added and the reaction mixture was allowed to warm to room temperature, stirred for an additional 1 hour and was then concentrated in vacuo. The residue was taken up in ethyl acetate (50 ml) and washed with water (1×20 ml), brine (1×20 ml), dried over magnesium sulfate, filtered and concentrated to afford 70 mg of a white solid which was dissolved in acetic acid (15 ml) and treated with zinc (excess) at room temperature (4 hours), 40° C. (2 hours) and at reflux (3 hours). Thin layer chromatography (90:10:1 chloroform:methanol:ammonium hydroxide) indicated the formation of 1H-thieno[3,4-d]imidazole-hexahydro-2-oxo-4-pentyl (3aα,4β,6aα). EXAMPLE 29 1H-thienzo[3,4-d]imidazole-2,4-dione, tetrahydro-6-pentyl (3aα,6β,6aα). To a methanol solution (20 ml) at 5° C. containing 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-oxo-1-pentyl, ethyl ester (1α,7β,7aα) (629 mg, 2.0 mmol) was added potassium hydroxide (129 mg, 2.0 mmol) in water (2 ml). The reaction mixture was stirred for 1 hour at room temperature, acidified to pH 3 with 1N HCL, extracted with ethyl acetate (3×100 ml), dried over magnesium sulfate, filtered and concentrated in vacuo to afford a white solid which was triturated with hexane:ether to give 327 mg of crude 3H,5H-imidazo[1,5c]thiazole-7-carboxylic acid, tetrahydro-3,3-dimethyl-5-oxo-1-pentyl (1α,7α,7aα) mp 210°-211° C. IR (KBr) 3359, 2927, 1733; NMR (DMSO) 0.7-2.3 (17H, m, CH 2 , CH 3 ), 3.0-4.7 (3H, m, CH) 6.7-7.03 (1H, m, NH). Analysis Calculated for C 13 H 22 N 2 O 3 S: C, 54.52; H, 7.74; N, 9.78. Found C, 54.50; H, 7.67; N, 10.05. This acid was dissolved in trifluoroacetic acid (4 ml), deuterium oxide (1 ml) was added and the solution was stirred at room temperature for 2 hours. The reaction mixture was concentrated in vacuo (3×) (toluene was used to azeotrope off water) to afford 289 mg of crude thiol which was placed in dry methylene chloride (125 ml) in the presence ot triethylamine (170 ml, 1.22 mol) at 0° C. Ethylchloroformate (117 ml, 1.22 mmol) was added and the reaction mixture was stirred for 2 hours at room temperature. The solvent was then concentrated under reduced pressure, and the white residue was taken up in ethyl acetate (80 ml)). The organic solution was washed with water (40 ml), dried over magnesium sulfate, filtered, and concentrated in vacuo to afford 270 mg of solids which were recrystallized from ethyl acetate to afford 110 mg of 1H-thieno[3,4-d]imidazole-2,4-dione, tetrahydro-6-pentyl (3aα,6α,6aα), mp 177°-180° C. IR (KBr) 3125, 2890, 1786, 1670. Analysis Calculated for C 10 H 16 N 2 O 2 S: 52.63; H, 7.02; N, 12.28. Found: 52.88; H, 7.15; N, 12.22. This thiolactone (21 mg, 0.09 mmol) was dissolved in tetrahydrofuran (2 ml), DBU 1,8-diazabicyclo[5.4.0]undec C-7 ene (1.38 μl, 0.009 mmol) was added and the solution was stirred for 20 minutes. IN HCL (100 l, 0.1 mol) was added and the reaction mixture was concentrated under reduced pressure, taken up in ethyl acetone (50 ml) and extracted with water. The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo to afford 21 mg of 1H-thieno[3,4d]imidazole-2,4-dione, tetrahydro-6-pentyl(3aα,6β,6aα).

A novel process is described for preparation of biotin comprising preparation of substituted 3H, 5H-imidazo[1,5c]tetrahydro thiazoles by contacting the boron trifluoride adduct of an appropriate thiazoline with the metallic derivative of an ester enolate, reducing the ester, hydrolyzing the thiazolidine moiety and hydrolyzing or oxidizing the resultant compound. Intermediates obtained in the preparation of biotin by the above process and alternate procedures for preparing said intermediates are also presented. A novel process for preparation of d-biotin is also given.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm management system. More particularly, the invention relates to a system and method for managing alarms in an industrial facility. Even more particularly, the present invention relates to a system and method for managing a plurality of alarms in a nuclear power plant. 2. Description of Related Art Day to day operations in most industrial facilities, including nuclear power generation plants, are typically uneventful. However, certain unscheduled events may occur that require the immediate attention of operational personnel. Thus, most process parameter monitoring systems are designed to include some type of warning system to alert operational personnel to an impending, or current, event requiring their attention. More specifically, these systems typically sound an audible alarm to alert operational personnel that a process parameter has exceeded a specified limit. Some unscheduled events may result in numerous alarms being sounded. These alarms may come from different systems, require differing levels of attention, and require attention by different operational personnel. Thus, when multiple alarms sound simultaneously or in momentary succession, operational personnel must determine what system each alarm is associated with, the priority level of each alarm, and which operator is responsible for attending to each alarm. This may result in confusion, missed alarms, inattention to certain alarms, or a combination of all of these factors, especially if the alarms are spread out around the facility. Designers have attempted to alleviate the above-mentioned factors to some extent in the nuclear power plant context. Specifically, modern nuclear power plants utilize a centralized control room design having computer-based workstations to allow convenient access to plant controls and functions from a single location. The workstations are divided into assigned operational responsibilities. For example, the reactor operator workstation encompasses controls and functions associated with reactor operations (e.g., primary plant systems including the nuclear reactor), and the turbine operator workstation encompasses controls and functions associated with secondary plant operations (e.g., steam plant systems). When one or more alarm situations occur, an alarm system outputs an audible tone to alert the control room operators. The system further causes the alarms to be depicted on workstation video display units as alarm lists, or highlighted on system mimic diagrams. The alarm lists may be filtered by certain categories such as by alarm priority or by the system in which the alarms occur. However, even modem centralized control room designs exhibit certain deficiencies. Specifically, when an audible tone is generated upon occurrence of a new alarm, the operators must manually determine which operator has responsibility for the alarm. This is accomplished by manually scanning an alarm list to determine if the new alarm is associated with the reactor operator or the turbine operator. Or, the control room operators must examine the various system mimic diagrams on the video display units to make the determination. Both of these operations are time consuming and distracting. Additionally, while the alarm lists may be filtered by certain categories, there is no coherent alarm status overview that allows an operator to conveniently observe the overall alarm-state of the plant and how the alarms are distributed. An operator can readily determine individual alarms and groups of related alarms using the category filtering function, but it is difficult to ascertain the overall plant alarm-state and determine the distribution of the alarms. Finally, present alarm systems provide no implementation that supports direct access to an operator's desired view of one or more alarms from a high-level plant alarm status overview. For example, an operator may wish to observe a new alarm from different perspectives, such as from an alarm list or from within a system mimic diagram to observe the context of the alarm relative to associated plant components and systems. With present alarm systems, an operator must either manually search through a display menu to select the desired system mimic diagram or manually recall an appropriate alarm list. Thus, there is a need for an alarm annunciation system that notifies operators immediately, upon the occurrence of one or more alarms, which operator has responsibility for each alarm. There is also a need for an alarm distribution indication system that presents a coherent view of the current plant alarm-state and the distribution of alarms by operator responsibility, priority, and system. There is additionally a need for a device for selectively displaying alarms that supports direct access to an operator's desired view of one or more alarms from a high-level plant alarm status overview. Finally, there is a need for an entire alarm management system that incorporates each of these features. SUMMARY OF THE INVENTION In one aspect of the present invention, an alarm management system comprises receiving means, comparing and generating means, receiving and transmitting means, and sound generation means. The receiving means receives one or more process parameter signals representative of one or more process parameters. The comparing and generating means compares each of the received process parameter signals with an associated alarm setpoint and generates an alarm status signal on the basis of the comparison. The receiving and transmitting means receives the alarm status signal and transmits an annunciation command signal on the basis of the received alarm status signal. The sound generation means generates a sound on the basis of the annunciation command signal. In another aspect of the present invention, an alarm annunciation system comprises receiving and transmitting means, tone generation means, and voice synthesization means. The receiving and transmitting means receives an alarm status signal and transmits an annunciation command signal on the basis of the received alarm status signal. The tone generation means generates a plurality of tones, each having a different frequency from another, on the basis of the annunciation command signal. The voice synthesization means synthesizes a human voice signal of a specified pitch on the basis of the annunciation command signal. In still a further aspect of the present invention, an alarm distribution indication system comprises memory means, information extraction means, information categorization means, and display means. The memory means stores alarm information of a plurality of alarms. The information extraction means periodically extracts the alarm information from the memory means. The information categorization means categorizes the extracted alarm information into to a plurality of predetermined categories. The display means displays the alarm information, for each of the plurality of alarms, arranged into the plurality of predetermined categories. In yet another aspect of the present invention, a device for selectively displaying a plurality of alarms, comprises a video display unit, an input selection device, information storage means, information categorization means, mimic display storage and generation means, and information transfer means. The information storage means stores alarm information for each of the plurality of alarms. The information categorization means periodically retrieves and categorizes the stored alarm information into a plurality of predetermined categories. The mimic display storage and generation means stores mimic display information for a plurality of process systems, and periodically retrieves the stored alarm information and generates the mimic display information for each of the plurality of process systems including the retrieved alarm information therein. The information transfer means receives a first command from the input selection device to select information and transfers the selected information to the video display unit for display thereon. The selected information includes one of the alarm information in one of the first plurality of predetermined categories, and the alarm information included in one of the plurality of process system mimic displays. In yet still a further aspect of the present invention, a method of managing a plurality of alarms includes the steps of receiving, comparing, generating an alarm status signal, receiving the alarm status signal, transmitting an annunciation signal, and generating a sound. In the receiving step, one or more process parameter signals representative of one or more process parameters are received. In the comparing step, each of the received process parameter signals is compared with an associated alarm setpoint. In the alarm status signal generating step, an alarm status signal is generated on the basis of the comparison in the comparison step. The alarm status signal is received in the alarm status signal receiving step. An annunciation command signal is transmitted on the basis of the received alarm status signal, in the annunciation command signal transmission step. A sound is generated on the basis of the annunciation command signal, in the sound generation step. The present invention provides distinct features and advantages over related alarm management systems and components. Specifically, an alarm annunciation system directs attention to the appropriate operational personnel whenever a new alarm is generated, or when an existing alarm condition returns to normal. Thus, operators are not required to manually determine which operator is responsible for the alarm. An alarm distribution indication system provides a single display page on a video display unit from which operators can conveniently ascertain the overall alarm state and alarm distribution. Thus, operators do not have to mentally construct an overview of the overall alarm state and distribution by examining and filtering various alarm lists. Additionally, a device for selectively displaying a plurality of alarms allows operators to conveniently and rapidly access one or more alarms based on a desired contextual view. Thus, operators do not have to manually search through a display menu to select a desired mimic display or manually recall the appropriate alarm list. These and other features and advantages of the present invention will become more apparent to those skilled in the art when the following detailed description is read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representation of an alarm management system according to the preferred embodiment of the present invention. FIG. 2 depicts a display page showing an alarm status overview that may be viewed on a workstation video display unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The alarm management system 10 , depicted schematically in FIG. 1, receives signals from one or more sensors 12 . The sensors 12 provide signals indicative of various process parameters within the industrial facility into which the system 10 is installed. In this regard, the term process parameter refers to physical parameters, such as temperature, pressure, flow rates, etc., and also refers to plant component status, such as valve positions, pump rotation speeds, vibration levels, etc. The skilled artisan will appreciate that the number of process parameters, and the specific physical parameters and component statuses, will vary according the application with which the alarm management system 10 is being used. The skilled artisan will further appreciate that various types of sensors known in the art may be used with the present invention. The signals provided from each sensor 12 are transmitted to a data acquisition system 14 , which may be any conventional data acquisition system known in the art. The sensor data is then transmitted from the data acquisition system to a digital computer 16 . The digital computer 16 may be a personal computer (PC), a plurality of networked computers, or a main frame computer. A plurality of alarm video display units 26 are located at operator workstations to display alarm information to operators. The number of alarm video display units 26 will depend upon the number of operators necessary for the particular plant. However, in the preferred embodiment, for a nuclear power plant, the number of workstations and alarm video display units 26 is two, one for the reactor operator and one for the turbine operator. Each operator workstation also includes an operator input device 28 , which allows the workstation operator to interface with the digital computer 16 . The operator input device 28 may be a trackball, a computer mouse, a touch-screen, a finger-pad, or any other device known to the skilled artisan. The operator input device 28 is used to acknowledge new alarms and clear alarms that have returned to normal. The operator input device 28 is also used to transmit a “link request,” discussed further below, to selectively display the alarms in a particular format on the associated alarm video display unit 26 . The alarm video display units 26 and operator input devices are connected to the computer 16 via a network connection 15 . The network connection 15 may a dedicated network connection or shared with other systems. Several modules within the computer 16 interact to achieve the desired functionality of the present invention. These modules may be separately designed individual hardware modules, conventional hardware modules programmed to perform specified functions, or may represent software modules which cause the digital computer 16 to perform each of the specified functions. The modules may be grouped into three main subsystems, all of which interact directly or indirectly with an alarm processing module 18 . These subsystems shown using dotted lines in FIG. 1, are a directive annunciator subsystem 30 , an alarm distribution overview indicator subsystem 40 , and an alarm view linker subsystem 50 . It should be noted that the alarm video display units 26 and operator input devices 28 , which are located at each workstation, are common to both the alarm distribution overview indicator subsystem 40 and the alarm view linker subsystem 50 . It should further be noted that these subsystems share certain functional modules and information when integrated together into a system, though each are described herein as separate subsystems. These facts will become apparent from the description of each of these subsystems provided below. It will be further appreciated by the skilled artisan that each of these subsystems could be utilized alone, or in any desired combination, to achieve a desired functional result. In the following description, a description of the operation of the alarm processing module 18 will be provided, followed by a detailed description of each of the subsystems. Alarm Processing Module The alarm processing module 18 compares the sensor data received from the data acquisition system 14 to associated alarm setpoints and generates appropriate alarm status signals on the basis of the comparison. The particular alarm status signal generated by the alarm processing module 18 will depend upon whether a datum exceeds a setpoint (a new alarm condition), or a datum that previously exceeded a setpoint is now below the setpoint (a return-to-normal condition). The alarm status signal generated by the alarm processing module 18 also includes various types of classification information to assist operators. This information includes the alarm priority classification, the operational responsibility classification, and the plant system classification. The priority classification information alerts the operator (or operators) to the relative importance of the alarm. Thus, an operator can readily distinguish between relatively important and unimportant alarms, and thereby prioritize recovery actions to minimize operational impact. The number of priority classifications can be varied to suit the particular use, but in the nuclear power generation context, the preferred number of priority classifications is three. In this respect, the priority classifications are labeled “Priority 1 ,” “Priority 2 ,” and “Priority 3 .” Priority 1 alarms are the last, and sometimes only, warning prior to reaching a “Significant Operator Action” condition. These alarms are generally related to the safety and availability of the plant, and include conditions associated with violations of critical reactor safety functions. If such conditions are not corrected immediately, a plant shutdown (manual or automatic), a radioactive release, or major equipment damage, will result. Priority 2 alarms are the next to last warning prior to reaching a “Significant Operator Action” condition. These alarms include conditions associated with plant technical specification violations that, if not corrected, will result in an eventual plant shutdown, or an eventual radioactive release. Priority 3 alarms are warnings prior to the next to the last warning before reaching a “Significant Operator Action” condition. If no significant operator action can result, these alarms are the only warning. Priority 3 alarms include conditions that, if left unattended, could result in a subsequent higher priority alarm condition. Such conditions typically indicate equipment or process anomalies. The operational responsibility classification indicates which operator is responsible to process the alarm. The number of operational classifications can also include any number necessary to meet the requirements of the environment in which the system is being employed. In the nuclear power generation context, however, the preferred number of operational responsibility classifications is two. These classifications are the reactor operator (RO) classification and the turbine operator (TO) classification. Thus, an alarm in the RO classification indicates that the reactor operator is responsible to process the alarm, and an alarm in the TO classification indicates that the turbine operator is responsible. The plant system classification indicates which plant system the alarm is associated with. Again, the number of system classifications can vary with the application. In the nuclear power generation context, the plant system classification would include, for example, the Chemical and Volume Control System, Reactor Coolant Pumps, Reactor Core, Main Feedwater System, Auxiliary Feedwater System, etc. The alarm processing module 18 also includes logic to suppress temporary alarms that occur due to plant transients or other momentary disturbances. These temporary alarms are not necessary for safe operation and are considered to be nuisance alarms since they do not reflect actual process parameter abnormalities. Directive Annunciator Subsystem The directive annunciator subsystem 30 is comprised of an annunciator logic module 32 , a tone generator 34 , a speech synthesizer 36 , and a speaker 38 . The directive annunciator subsystem 30 interacts with other components and subsystems to provide audio notification of new alarm conditions, and return-to-normal conditions. The audio notification also provides appropriate operator responsibility classification information to operators. Specifically, whenever the alarm processing module 18 determines that a new alarm condition or a return-to-normal condition exists, the alarm processing module 18 sends an updated alarm status signal to the annunciator logic module 32 . The annunciator logic module 32 receives the alarm status signal, and the information contained therein, to determine an appropriate audio output command for the specific condition. The appropriate audio output command is sent to both the tone generator 34 and the speech synthesizer 36 , via the network 15 . The tone generator 34 produces a plurality of alarm tones of differing frequencies to alert the operator to a new alarm condition, a return-to-normal condition, or to alert the operator that a new alarm has not been acknowledged. The speech synthesizer 36 generates voice messages to direct attention to the proper operational responsibility for both a new alarm condition and a return-to-normal condition. As with the tone generator 34 , voice messages of differing frequencies are used to differentiate between the operational responsibility for the alarm. The voice frequencies generated by the speech synthesizer 36 can be selected based on the desired effect and number of differing operational responsibility categories. In the preferred embodiment, however, where the system is used in a nuclear power plant, two different voice frequencies are used. A substantially male sounding voice is used for reactor operator responsibility alarms, and a substantially female sounding voice is used for turbine operator responsibility alarms. The operation of the directive annunciator subsystem will be explained below for various exemplary conditions. If the alarm processing module 18 determines that a new alarm condition exists, it sends an appropriate signal to the annunciator logic module 32 . The annunciator logic module 32 then sends appropriate commands the tone generator 34 and the speech synthesizer 36 . The tone generator 34 then generates a momentary tone (e.g., approximately 1 second in duration), to alert the operators to the new alarm condition. Immediately thereafter, the speech synthesizer 36 generates an appropriate sounding voice message directed to the appropriate operator. In the preferred embodiment, if the responsible operator is the reactor operator, the voice message would be a substantially male sounding voice stating, “New reactor alarm(s).” If the responsible operator is the turbine operator, the voice message would be a substantially female sounding voice stating, “New turbine alarm(s).” Moreover, if several new alarms occur simultaneously, some being the reactor operator's responsibility and some being the turbine operator's responsibility, the voice message would state, “New reactor alarm(s) and new turbine alarm(s).” In this instance, a substanatially male sounding voice is used for the former part of the message (e.g., “New reactor alarm(s)”), and a substantially female sounding voice for the latter part (e.g., “and new turbine alarm(s).”). Upon receipt of the tone and voice message, the appropriate operator can then view the alarm(s) on the associated alarm video display unit 26 , and use the operator input device 28 associated with the workstation to acknowledge the alarm. The operator can then take appropriate action. When the operator acknowledges the new alarm using the operator input device 28 , the alarm information in the current alarm file 42 is updated to reflect this acknowledgement. If the alarm processing module 18 determines that one or more return-to-normal conditions exist, it sends an appropriate signal to the annunciator logic module 32 . The annunciator logic module 32 in turn commands the tone generator 34 and speech synthesizer 36 to generate an appropriate tone followed by an appropriate voice message, respectively. Specifically, a tone different from the new alarm condition tone is momentarily generated (e.g., for approximately 1 second) by the tone generator 34 . Then, the voice synthesizer 36 outputs a voice message of appropriate frequency. For instance, in the preferred embodiment of the invention, if the return-to-normal condition is associated with a reactor operator responsibility alarm, the voice message would be a substantially male sounding voice stating, “Cleared reactor alarm(s).” Likewise, if the return-to-normal condition is associated with a turbine operator responsibility alarm, the voice message would be a substantially female sounding voice stating, “Cleared turbine alarm(s).” Finally, if the return-to-normal condition is associated with a plurality of alarms, some being associated with the reactor operator's responsibility and some being associated with the turbine operator's responsibility, the voice message would state, “Cleared reactor alarm(s) and cleared turbine alarm(s).” Again, in this instance a substanatially male sounding voice is used for the former part of the message (e.g., “Cleared reactor alarm(s)”), and a substantially female sounding voice for the latter part (e.g., “and cleared turbine alarm(s).”). Upon receipt of the tone and voice message, the appropriate operator can then use the operator input device 28 associated with the workstation to clear the alarm. When the operator clears the alarm, the alarm information in the current alarm file 42 is updated to reflect that it is cleared. As noted above, upon receipt of a new alarm condition or a return-to-normal condition, as appropriately annunciated by the new alarm tone and voice message, the operator uses the operator input device 28 to acknowledge the alarm or the return-to-normal condition. If either condition is not acknowledged within a predetermined period of time, the directive annunciator subsystem 30 provides a reminder notification to the operator. To generate the reminder notification, the alarm processing module 18 periodically scans the information in the current alarm file 42 to determine if any alarm conditons have not been acknowledged or return-to-normal conditions have not been cleared. If either of these conditions exists, the alarm processing module 18 directs an appropriate alarm status signal to the annunciator logic module 32 . The annunciator logic module 32 then commands the tone generator 34 and voice synthesizer 36 to generate an appropriate tone and voice message, respectively. Specifically, a momentary tone having a unique frequency, would be followed immediately by an appropriate voice message. For instance, in the preferred embodiment, for unacknowledged alarms or uncleared (return-to-normal) conditions associated with reactor operator responsibility, the voice message would state, “Unacknowledged (Uncleared) reactor alarm(s).” For unacknowledged alarms or uncleared (return-to-normal) conditions associated with turbine operator responsibility, the voice message would state, “Unacknowledged (Uncleared) turbine alarm(s).” And, for a plurality of unacknowledged (uncleared) alarms, some being associated with the reactor operator's responsibility and some being associated with the turbine operator's responsibility, the voice message would state, “Unacknowledged (Uncleared) reactor alarm(s) and unacknowledged (uncleared) turbine alarm(s).” Once again, in this instance a substanatially male sounding voice is used for the former part of the message (e.g., “Unacknowledged (Uncleared) reactor alarm(s)”), and a substantially female sounding voice for the latter (e.g., “and unacknowledged (uncleared) turbine alarm(s).”). If new alarms occur before a previous alarm is acknowledged, the new alarm will be initially annunciated with the appropriate tone and voice message. The reminder tone will be periodically output thereafter until all unacknowledged alarms have been acknowledged. The similar function occurs if new return-to-normal conditions occur before previous ones are cleared. Alarm Distribution Overview Indicator The alarm distribution overview indicator subsystem 40 comprises the current alarm file 42 , an alarm status overview module 44 , and one or more alarm video display units 26 . The alarm distribution overview indicator subsystem 40 interacts with other subsystem modules to provide a coherent status overview of overall alarm status. In other words, how the alarms are distributed. This function of this subsystem will now be described. The alarm status overview module 44 periodically searches through the alarm information stored in the current alarm file 42 . The search periodicity is not critical to the inventive concept, but in the preferred embodiment it is approximately every second. The stored information includes the alarm status information (e.g., whether the alarm is new; whether the alarm, if new, has been acknowledged; and whether the alarm has returned-to-normal). And, as discussed previously, the stored information also includes the information associated with the each alarm's priority classification, operational responsibility classification, and plant system classification. The alarm status overview module 44 , during the search period, extracts the information and arranges it according to both its status and classification. The information so arranged by the alarm status overview module 44 is then sent to one or more of the alarm video display units 26 . An exemplary display page 60 view of the alarm status overview that a alarm video display unit 26 would provide is illustrated in FIG. 2 . An operator viewing this display page 60 is presented with an overall alarm distribution summary, according to each alarm's status and its specific operational responsibility (or “Work Scope”), alarm priority, and system classifications. Thus, within each of the specific classifications, the display page 60 depicts the number of alarms that are new, acknowledged, and returned-to-normal. The display page 60 also depicts the total number of alarms that are new, acknowledged, and returned-to-normal. As shown in the right-hand portion of FIG. 2, the display page 60 also depicts various links 62 . These links 62 are used with the alarm view linker subsystem 50 . The alarm view linker subsystem 50 interacts with other subsystem modules and allows an operator to directly link, from the display page 60 , to a desired alarm view. Thus, the operator can view alarm information from various perspectives. Specifically, the operator can view the alarms from a system mimic diagram display perspective, or an alarm list perspective. Alarm View Linker The alarm view linker subsystem 50 comprises a link module 52 , an alarm list generator module 54 , a VDU display set module 56 , and one or more workstation alarm video display units 26 and associated operator input devices 28 . Using the operator input device 28 , an operator makes a “link request” for a specific alarm view by designating the appropriate link 62 . For example, if the operator input device 28 is a touch-screen, and the operator wishes to view a list of alarms having a Priority I classification, the operator would touch the display page 60 at the link 62 displaying “P- 1 .” Or, if the operator wishes to view alarms associated with a particular system on a system mimic diagram, the operator would touch the display page at the link 62 under the Mimic Display column displaying the particular system designation. The link module 52 recognizes the link request made by the operator, via the operator input device 28 , and outputs the appropriate view, either a list or system mimic diagram display, to the associated alarm video display unit 26 . The link module 52 retrieves the desired information for display from the alarm list generator module 54 for alarm list display links, or from the VDU display set module 56 for system mimic diagram display links. The alarm list generator module 54 periodically retrieves the alarm information stored in the current alarm file 42 and generates a series of lists. Each list contains a chronological listing of each alarm within the selected alarm list classification, and includes specific and detailed information about the alarm condition. More specifically, the alarm list generator module 54 generates separate lists for each operational responsibility classification, each priority classification, each system classification, and a total alarm list. For example, according to the preferred embodiment, wherein the system is installed in a nuclear power plant, the alarm list generator module 54 generates the following lists: RO Alarm List, TO Alarm List, ALL Alarm List, Priority 1 Alarm List, Priority 2 Alarm List, Priority 3 Alarm List, and various SYSTEM Alarm Lists. The RO and TO Alarm Lists contain, respectively, a chronological listing of all RO and TO alarms (both new and acknowledged) and RO and TO alarms that have returned-to-normal (but not yet cleared). These lists can be further filtered, via the operator input device 28 , to indicate, respectively, only the new (unacknowledged) RO and TO alarms, only the RO and TO alarms that have returned-to-normal but have not been cleared, or only the RO and TO alarms that have returned-to-normal by alarm priority level. With the latter filtration, Priority 1 alarms are listed first in their chronological order of occurrence, followed concomitantly by Priority 2 alarms then Priority 3 alarms. It should be noted that this filtration scheme is not limiting and other filtration schemes can be used to display various subsets of the RO and TO alarm lists. The ALL Alarm List contains alarm information similar to that described for the individual RO and TO alarm lists, including the specified filtration scheme. However, this list contains the total number of alarms, regardless of operational responsibility. The Priority 1 , 2 , and 3 Alarm Lists contain, respectively, a chronological listing of all Priority 1 , 2 , and 3 alarms (new and unacknowledged) and Priority 1 , 2 , and 3 alarms that have returned-to-normal, regardless of operational responsibility. These lists may be further filtered, via the operator input device 28 , to indicate, respectively, the Priority 1 , 2 , and 3 alarms associated with either the RO and/or the TO. The SYSTEM Alarm Lists each contain a chronological listing of all alarms associated with a particular system. Since each system is typically associated with either the RO or the TO, the operational responsibility information is inherently contained within each list. However, certain systems do have alarms that fall under the operational responsibility of both the RO and TO. For such systems, the particular SYSTEM Alarm List may be further filtered accordingly. The VDU display set module 56 stores all of the mimic diagram displays associated with each system. The system mimic diagram displays are organized in a hierarchical order, and contain alarm information graphically depicted in the context of plant systems, components, and processes. Similar to the alarm list generator module 54 , the VDU display set module 56 periodically retrieves the alarm information from the current alarm list module 42 , and updates the mimic diagram displays accordingly. The VDU display set module 56 includes color coding, shape coding, and dynamic behavior (such as blinking) to indicate the presence of alarms and to indicate the alarm state (i.e., new alarms, acknowledged alarms, returned-to-normal alarms). For example, alarms that appear on a system mimic diagram display as an alphanumeric value will change from a “normal value” color to the “alarm value” color at the point in the system mimic diagram where the alarming parameter is being monitored. If the specified alarm has a dynamic alarm behavior associated with it, such as blinking, this behavior will also be depicted on the system mimic diagram display. Additionally, if a particular component in a system is controlled when an alarm condition occurs, such as a pump or a valve, the component symbol on the system mimic diagram display will be depicted with the appropriate alarm condition color, shape, and/or dynamic behavior. While preferred embodiments of the present invention have been illustrated in detail, it is apparent that modifications and adaptations of the preferred embodiments will occur to those skilled in the art. However, it will be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention as set forth in the following claims.

An alarm management system and method includes structure and function for receiving one or more process parameter signals representative of one or more process parameters. Each of the received process parameters is then compared with an associated alarm point. An alarm status signal is generated on the basis of the comparison. An annunciation command signal is transmitted on the basis of the alarm status signal. And, a sound is then generated on the basis of the annunciation command signal.

CROSS-REFERENCE TO RELATED APPLICATIONS This Application is related to U.S. patent applications Ser. No. 617,246, entitled IMPROVED RECIRCULATING DOCUMENT FEEDER, filed in the name of Russel et al; Ser. No. 617,337, entitled IMPROVED RECIRCULATING DOCUMENT FEEDER HAVING A CROSS-TRACK REGISTRATION MECHANISM, filed in the name of Rapkin et al; Ser. No. 617,249, entitled IMPROVED RECIRCULATING DOCUMENT FEEDER WITH STACK WEIGHT DETERMINED PRESSURIZED AIR/VACUUM LEVELS, filed in the name of Russel; Ser. No. 617,247, entitled IMPROVED RECIRCULATING DOCUMENT FEEDER WITH CONTROL OF DOCUMENT SHEET TRANSPORT, filed in the name of Russel et al; Ser. No. 617,336, entitled SEPARATION MEMBER FOR AN IMPROVED RECIRCULATING DOCUMENT FEEDER, filed in the name of Lawniczak; and Ser. No. 617,248, entitled MECHANISM FOR FACILITATING DOCUMENT SHEET SETTLING IN AN IMPROVED RECIRCULATING DOCUMENT FEEDER, filed in the name of Bergeron et al. All of these applications have been allowed. BACKGROUND OF THE INVENTION This invention relates in general to recirculating document feeders for use with electrostatographic reproduction apparatus, and more particularly to a recirculating document feeder having improved document sheet handling reliability due to a self-adjusting relation between the feeder and the reproduction apparatus. In order to increase the productivity and ease of use of electrostatographic reproduction apparatus, it has been common practice to provide such apparatus with automatic document set handlers Early automatic document set handlers accepted a document set stack and removed individual document sheets from the stack one at a time (see U.S. Pat. No. 3,747,918, issued Jul. 24, 1973, in the name of Margulis et al). The removed document sheet was delivered to an exposure station of the reproduction apparatus where the desired number of reproductions of such document sheet were made. Thereafter, the document sheet was returned to the stack and the next document sheet was delivered to the exposure station. Such sequence of document sheet feeding and reproduction necessitated the use of an auxiliary sorter device in conjunction with the reproduction apparatus to provide collated reproduction sets corresponding to the document set. The use of a sorter device added to both the complexity and expense of the reproduction operation. More recently, automatic document handlers typically referred to as recirculating document feeders have been developed. Recirculating document feeders, such as shown for example in U.S. Pat. No. 4,169,674 (issued Oct. 2, 1979, in the name of Russel) deliver document sheets seriatim to the reproduction apparatus exposure station and return the sheets to the document stack in order. At the exposure station, only one reproduction of each respective document sheet is made on one circulation. The desired number of reproductions is made by recirculating the document sheets from the stack to the exposure station and then back to the stack a corresponding number of times. By such reproduction sequence, the reproduction set of the document set is received at an output hopper in collated order. Thus no subsequent operational steps on the reproduction set are required. While recirculating document feeders have proven very popular in that they enhance productivity and increase ease of use of the reproduction apparatus, they require complex construction to reliably recirculate the document sheets and effectively handle the document sheets in a manner to prevent damage thereto. Further, the relationship between the recirculating document feeder and the reproduction apparatus has to be accurately set up and constantly maintained to remain in adjustment. This is necessary to assure proper feeding operation of the document sheets through the interface between the recirculating document feeder and the reproduction apparatus. It is typically required that such set up and adjustment maintenance be accomplished by a trained service technician or a technically skilled operator. This adds considerably to the overall cost of maintaining the apparatus in proper working order. SUMMARY OF THE INVENTION This invention is directed to an improved recirculating document feeder for presenting sheets from a document sheet stack individually to a station of the reproduction apparatus for reproducing of information contained on such sheets, the recirculating document feeder having a self-adjusting relationship with the reproduction apparatus. The improved recirculating document feeder comprises a housing containing a support for a document sheet stack. A feed path extends away from and then back to the document stack support, for directing sheets from the support into association with the reproducing station and then back to the stack. Document sheets are selectively fed from the stack seriatim about the feed path. The feed for the document sheets includes a transport assembly overlying at least a portion of the reproduction apparatus station. The transport assembly is mounted for movement relative to the housing, and engageable by a spacer associated with the reproduction apparatus station for self-adjustment of the transport assembly in the mount to locate the transport assembly a predetermined distance from the reproduction apparatus station irrespective of the position of the housing relative to said reproduction apparatus station. The invention, and its objects and advantages, will become more apparent in the detailed description of the preferred embodiment presented below. BRIEF DESCRIPTION OF THE DRAWINGS In the detailed description of the preferred embodiment of the invention presented below, reference is made to the accompanying drawings, in which: FIG. 1 is a general view, in perspective, of a typical reproduction apparatus with the improved recirculating document feeder according to this invention in operative association therewith; FIG. 2 is a front elevational view, in cross-section and on an enlarged scale, of the improved recirculating document feeder according to this invention; FIG. 3 is a top plan view of a portion of the improved recirculating document feeder, with portions removed to facilitate viewing, particularly showing the document sheet stack support tray, side guide adjustment mechanism, and set count finger assembly; FIG. 4 is a top plan view of a portion of the improved recirculating document feeder similar to FIG. 3, with portions removed to facilitate viewing, particularly showing the document sheet stack support tray and feed belts; FIG. 5 is a side elevational view, in cross-section, of the portion of the recirculating document feeder shown in FIG. 4, taken along lines 5--5 of FIG. 4; FIG. 6 is a view, in perspective, of the set count separator assembly of the recirculating document feeder according to this invention; FIG. 6a is a top plan view of the set count separator assembly of FIG. 6 showing the remote position of the assembly finger in phantom; FIG. 7 is a side elevational view of a portion of the improved recirculating document feeder, with portions removed to facilitate viewing, particularly showing the cross-track adjustment and registration mechanism; FIG. 8 is front elevational view of a portion of the improved recirculating document feeder, with portions removed to facilitate viewing, particularly showing the individual document sheet positioner therefor; FIG. 9 is a graphical representation depicting the relationship between the number of document sheets in a document sheet stack and the pressure supplied to the air jet assembly; and FIG. 10 is a graphical representation depicting the relationship between the number of document sheets in a document sheet stack (for a particular sheet weight) and sensor signal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the accompanying drawings, FIG. 1 shows a typical reproduction apparatus 10 having the improved recirculating document feeder according to this invention, designated generally by the numeral 12, associated therewith. The reproduction apparatus 10 may be for example an electrostatographic copier, a thermal or electronic printer, or a photographic printer. The requirement common for any selected typical reproduction apparatus is that it includes a reproducing station where a document sheet is received, and information contained on the document sheet is extracted for reproduction by the apparatus. An example of such a reproducing station is a transparent platen where a document sheet placed thereon is exposed by a light source to obtain a reflected light image of the contained information. Of course, it is suitable for this invention to optically or electronically scan the document sheet in any well known manner to obtain the information for reproduction. Further, the reproduction apparatus 10 includes an electronically based control system, or the like, such as a microprocessor based controller, which communicates with the recirculating document feeder 12 to operate the feeder in coordinated synchronism with the reproduction apparatus. As best seen in FIGS. 2-8, the improved recirculating document feeder 12 includes a housing 16 attached to the reproduction apparatus 10 for pivotable movement about an axis A (see FIG. 1) to a position for locating the feeder in operative association with the reproducing station 14, or a position remote from the station to provide ready access thereto. A document sheet stack receiving hopper 18 having a tray formed by a stack supporting surface 18a is located within the housing 16. When the housing is operatively associated with the reproducing station 14, the hopper supporting surface 18a is positioned at an angle to the horizontal. Accordingly, a document sheet stack (designated generally by the letter S) placed in the hopper 18 on the surface 18a is urged by gravity such that the individual sheets in the stack are respectively aligned along one edge against a locating wall 20 disposed transversely relative to the document sheet travel path to be described hereinbelow. Side guides 22 (see FIGS. 3, 4) are adjustably positioned to engage marginal edges of the document sheet stack adjacent to the sheet edge engaging the wall 20 to properly locate the sheet stack in the direction transverse to the sheet travel path. Adjustment of the side guides is accomplished, for example, by a manually operated rack-and-pinion system 22a as shown in FIG. 3. A mechanism 22b, such as an adjustable potentiometer connected by a gear to the system 22a for example, provides a signal to the operating computer of the reproduction apparatus 10 to indicate the setting (document sheet size) of the side guides 22. The area immediately above the hopper 18 is unobstructed so that the operator can readily place a document sheet stack S in the hopper and always have a clear view of the document sheets in the stack in the hopper. The document sheet stack is loaded in the hopper 18 in its natural (page sequential) order with the first page of information facing upwardly. To facilitate feed (removal) of document sheets from the hopper 18 into the document sheet feed path, the stack supporting surface 18a of the hopper has a depressed portion 18b located adjacent to the side of the hopper opposite the wall 20. A document sheet removal device 24 is located in juxtaposition with the depressed portion 18b of the stack supporting surface 18a of the hopper 18. As best seen in FIGS. 4 and 5, the document sheet removal device 24 includes a plurality of belts 26. The belts 26, which are selectively driven about a closed loop path, are entrained around a vacuum plenum 28 connected to a vacuum blower V (see FIG. 2) and have a run at a level substantially coincident with the depressed portion 18b. The plenum 28 has a series of ports 28' in the upper surface thereof, such ports communicating with apertures 26' in the belts 26. Vacuum in the plenum draws the bottommost document sheet in the stack S on the supporting surface 18a into the depressed portion 18b to effect attachment of such sheet to the belts 26 (see FIG. 5). Movement of the belts 26 about their path will then cause such bottommost sheet to be removed from the stack. The ease with which a document sheet can be removed from the bottom of a document sheet stack is dependent, at least in part, upon the sheet stiffness and weight, the overall weight of the document sheet stack, and the frictional force relationship between the bottommost sheet and the sheet immediately thereabove, the bottommost sheet and the supporting surface 18a of the hopper 18, and the bottommost sheet and the belts 26. In order to assure reliable document sheet removal, pressurized air is directed from an air pump P through an air jet assembly 30 toward the edge of the stack opposite the stack edge engaging wall 20 (i.e., the lead edge of the stack in the direction of sheet travel). The orientation of nozzles 30' of the air jet assembly 30 causes positive pressure air flow to be introduced between individual sheets of the document sheet stack S in the hopper 18. Such air flow levitates and separates the document sheets of the sheet stack. The force necessary to remove the bottom most sheet from the stack is thus reduced and misfeeds or multiple sheet feeds are substantially prevented. The introduction of positive pressure air flow by the air jet assembly 30 reduces the frictional force between the bottommost sheet and the sheet immediately above it. However, such air flow also increases the frictional force between the bottommost sheet and the hopper supporting surface 18a. Accordingly, the coefficient of friction properties of the feed belts 26 in contact with the bottommost sheet, the coefficient of friction between bottommost sheet and the supporting surface 18a, and the areas and surface roughnesses of these interacting elements must be taken into account to establish a desired level of vacuum necessary for the feed belts to remove only the bottommost sheet from the hopper 18a for delivery into a downstream travel path. The graphical representation of FIG. 9 shows the air jet assembly operating window for the recirculating document feeder 12 according to this invention, which extends from one document sheet to well over 100 sheets. Through the range of the number of document sheets in the document sheet stack in the recirculating document feeder (which determines the weight of the document sheet stack against the frictional surfaces thereof), it has been found necessary to either constantly vary the amount of vacuum and positive pressure air flow (line designated by the letter X in FIG. 9) or to vary those parameters in discrete steps (line designated by the letter Y in FIG. 9) such that the vacuum and pressurized air flow levels always define an operating point within the boundaries of the operating window. Operation at or near the boundary may result in lowered document sheet feeding reliability. This is due to the fact that too high an air flow may cause the document sheet stack to become disheveled, and insufficient air flow may enable the vacuum to effect multi-sheet feeds. When the air flow is kept within the defined operating window, the operation of the recirculating document feeder 12 has been reliable with document sheets in the range of thin papers (e.g., 13 lb. bond) up to and including heavy index and cover grades (e.g., 110 lb. index stock and 80 lb. cover stock). In order to establish the height of the document sheet stack, a set count assembly 32 (see FIGS. 3 and 6) is provided. The set count assembly 32 is located adjacent to wall 20 at the trailing edge of the document sheet stack S, and includes an elongated separator member in the form of a movable finger 32a. The finger 32a, extending through a slot 20a in the wall so as to overlie the trailing edge of the stack in the hopper 18, is supported on interconnected pivot rods R 1 , R 2 for pivotal movement about the two mutually perpendicular longitudinal axes of such rods. The rod R 1 permits the finger 32a to pivot such that the finger can freely follow the level of the initial topmost document sheet in the stack S supported on the stack supporting surface 18a of the hopper 18. On the other hand, rod R 2 is coupled to a rotary solenoid RS which upon actuation of the solenoid pivots the finger 32a to and from a remote position (phantom line position of FIG. 6 a). The end portion of the finger 32a, opposite to the end portion engaging the initial topmost document sheet in the stack S, engages a cam member C. The cam member C has a profile which, upon pivot movement of the finger 32a about the longitudinal axis of rod R 2 by the rotary solenoid RS after the initial topmost sheet is fed from the hopper 18, causes the finger to move to its remote position, to be raised to a level above the maximum stack height accommodated in the hopper, and returned to its initial position (solid line position of FIG. 6a) to once again engage the initial topmost sheet returned to the stack S. In operation, at the beginning of a reproduction cycle, the set count finger 32a is located so as to contact the initial topmost sheet of the document sheet stack. A sensor 34 detects the position (height above the stack supporting surface 18a) of the set count finger 32a resting on the top of the document sheet stack S, and thus enables the thickness of the stack (which is also a simple measure of the number of sheets in the stack) to be determined. The sensor 34 provides a signal which communicates with the operating computer of the reproduction apparatus 10 to enable the computer to set the speed of the vacuum blower V and/or adjust various valves (not shown) to proportion the pressurized air and vacuum levels to levels that have been predetermined to provide satisfactory operation for the detected number of document sheets in the stack. Alternatively, several switches may be used to accomplish measurement of the document sheet stack height, detecting for example that the stack contains less than 10, between 10 and 50, or more than 50 sheets. The set count assembly 32 also includes a sensor 36 which detects when the last document sheet of the stack S (the one which initially was topmost at the start of the reproduction cycle) has been fed from the hopper 18. An opening 18c defined in the sheet supporting surface 18a of the hopper is located to enable the set count finger 32a to drop through the supporting surface to a position below the supporting surface when the last document sheet has been fed. At such position, the sensor 36 "sees" the set count finger and provides a signal which communicates with the reproduction apparatus computer to indicate that a reproduction of the entire document sheet stack has been completed. The computer can then precisely determine the number of document sheets in the stack, since it has been counting the number of sheets fed as the reproduction cycle has progressed. At the completion of reproduction of the first document sheet stack set, the computer can readjust the pressurized air and vacuum levels to levels corresponding to the optimum operating levels for the particular number of document sheets in that document sheet stack. Further, a sensor 38 (see FIG. 3) is mounted in association with the side guides 22 to detect the location thereof. The sensor 38 provides a signal which communicates with the reproduction apparatus computer to indicate the setting for which the side guides 22 have been adjusted (i.e., for the size of the document sheets that the side guides have been adjusted to accommodate). Input of the size of the document sheets enables the computer to calculate or otherwise determine the total weight of the document sheets in the hopper 18. Based upon the determined total weight of the document sheet stack, the computer can then provide for an additional adjustment of the pressurized air and vacuum levels to produce optimum performance and maximum reliability of the recirculating document feeder 12. If the pressurized air flow is too high, it can cause excess fluffing of the document sheet stack. Excess fluffing of the sheet stack creates a condition where, at the completion of reproduction of a document sheet stack set, the set count finger 32a can be improperly returned to other than the top of the sheet stack. To avoid such condition, the reproduction apparatus computer is programmed to pause after the end of a reproduction cycle for the document sheet stack set (as determined by sensor 36 detecting the set count finger 32a), and turn off the air pressure momentarily. This enables the stack to settle in the hopper 18 and the set count finger 32a to return reliably to rest on the top sheet of the settled stack. Then the computer, knowing exactly the number of document sheets, can readjust the pressurized air and vacuum level settings. Since heavy weight document sheets are ordinarily thicker than light weight document sheets, determining the number of sheets in the document sheet stack is not a perfect measure of the stack weight. However, by comparing the document sheet stack height as determined by the stack height sensors with the actual count of the number of document sheets, the reproduction apparatus computer can calculate the thickness of each sheet. Suppose, for example, that there is only one stack height sensor (e.g., sensor 34) set to detect if there are more than ten sheets of 20 lb. bond paper in the hopper 18. When the reproduction cycle starts, the set count finger 32a is placed on top of the stack. If the sensor detects that there are more than ten sheets of paper, the computer does not know how many more sheets are in the stack, nor does it know what the thickness (and thus the weight) of each sheet is, nor can it calculate the total weight of the stack. In this example, if the computer counts 25 sheets when it senses the end of reproduction of the first document sheet stack set, it still does not know the thickness of each sheet. The best the computer can do is adjust the pressurized air and vacuum levels to levels corresponding to the center of the operating window for 25 sheets with a weight equivalent to 20 lb. bond paper (most commonly used and nearest to average sheet weight). If, however, the sheets are actually 110 lb. index stock instead, they will weigh about twice as much as 25 sheets of 20 lb. bond paper. For optimum operation on 110 index stock, the pressurized air and vacuum level settings should be relatively increased to provide better levitation of the stack above the bottommost sheet and an increased driving force between the drive belts and the bottommost sheet to better pull the bottommost sheet out from underneath the weight of the stack above it. If, however, the stack height sensor 34 initially detects that there are fewer than ten sheets of 20 lb. bond paper, the computer can set the pressurized air and vacuum levels accordingly, but it still does not know exactly how many sheets there are in the stack, nor their weight. In order to provide for more accurate control of the pressurized air and vacuum level settings, the following method may be employed. Suppose, for example, that on start of the reproduction cycle, the sensor 34 detects that more than the equivalent of ten sheets of 20 lb bond paper are contained in the stack in the hopper 18. The reproduction apparatus computer, on receipt of the appropriate signal from the sensor 34, sets the initial pressurized air and vacuum levels. As the reproduction cycle continues, at some point the set count finger 32a will pass through the point at which it senses ten sheets of 20 lb. bond paper. From that point on, the computer tallies a second count of the number of sheets to the completion of reproduction of the document sheet stack set. If the computer counts approximately ten sheets, then it knows that the sheets are probably 20 lb. bond paper; if it counts approximately five sheets, then it can deduce that the sheets are a heavier grade, like 110 lb. index stock; and if it counts approximately twenty sheets, then it can deduce that the sheets are probably 13 lb. bond paper. Now the computer has enough information to determine the weight of the entire stack since it also knows the total number of sheets in the document stack and can multiply the total number of sheets by the deduced weight of each sheet. This additional information is sufficient to alter the pressurized air and vacuum level settings to approximate optimum level settings for the determined stack height and weight The setting of pressurized air and vacuum levels is most critical for sheet stacks of heavy weight papers. The described additional intelligence that the computer gains from deducing the individual sheet weight allows the earliest possible optimization of operating parameters for the recirculating document feeder 12 to be attained. On the other hand, for stacks with fewer than ten sheets, precise setting of the vacuum level is not as important. That is, with smaller stacks, excess gripping force between the feed belts 26 and the bottommost sheet is not a disadvantage unless the paper is porous enough so that the next bottommost sheet in the sheet stack is also attracted to the belts (which can result in a multiple sheet feed). Setting of the air pressure level for the air jet assembly 30, however, is more critical with only a few sheets since excess air pressure may cause the sheets to be lifted entirely out of the hopper 18. Accordingly, to improve the ability to optimally provide for pressurized air and vacuum level settings, it is desirable to provide at least two levels of pressurized air and vacuum level settings and two stack height sensors (e.g., 34 and 34 a) for determining the initial start-up operating parameters. For document sheet stacks containing less than the minimum number of sheets detectable by the stack height sensor (i.e., ten sheets in the above example), the computer still does not know whether the weight of the sheets is light, medium, or heavy. But, since the operating window is sufficiently wide, it has been found that reliability for recirculating sheets of smaller stacks is not appreciably degraded. The second stack height sensor 34a enables a finer determination of the height of the document sheet stack to be made; e.g., less than five sheets, between five and ten sheets, and more than ten document sheets. With such a sensor arrangement, the reproduction apparatus computer can tally the number of sheets required for actuating the different stack height sensors as the set count finger 32a passes through the range from the start of the reproduction cycle to the end of the cycle. If the computer starts out knowing, for example, that there are more than ten sheets, it can wait until the ten-sheet sensor is actuated, then tally the number of feed cycles necessary to detect the actuation of the five-sheet sensor. If the number of document sheet feeds is approximately five, then the document sheets are probably 20 lb. bond paper. If the tally is only two or three, then the sheets are probably 110 lb. index stock, and the pressurized air and vacuum level settings can be adjusted without having to wait until the end of a reproduction cycle for the document sheet stack set. The earlier the setting determination is made, the sooner the operating parameters can be optimized so as to enhance the reliability of document sheet separation and feeding. The concept of utilizing multiple stack height detection sensors can be carried to its ultimate extent by employing an analog stack height sensor rather than the discrete (digital) sensors (34, 34a) described above. When the set count finger of the set count assembly comes to rest on the top of the document stack, the analog sensor provides an analog voltage signal (directly corresponding to stack height) to the reproduction apparatus computer. Accordingly, for each position of the set count finger, the computer can calculate the number of document sheets in the stack. The graph of FIG. 10 shows a straight-line correspondence between the document sheet stack (set count finger) height and number of document sheets for various weights of paper (i.e., line E corresponds to 110 lb. index stock, line F corresponds to 20 lb. bond paper, and line G corresponds to 13 lb. bond paper). As the reproduction cycle begins, the pressurized air and vacuum level settings are set at a default (compromise) condition since the computer does not know whether the document sheets in the stack are heavy or light in weight. As the reproduction cycle continues, however, the computer can count the number of feed cycles and compare the actual count of document sheets fed with the calculated number of document sheets based on the instantaneous height of the set count finger. From this comparison, the computer can match the slope of the actual straight line correspondence between the set count finger height and the number of sheets with one of the theoretical paper weight lines (lines E, F, or G) to determine the individual sheet weight. According to such determination, the computer can accurately predict the number of sheets in the document sheet stack and the weight of the stack within only a few sheets, and readjust the pressurized air and vacuum level to optimum settings. Another way of looking at the concept of utilizing the analog stack height sensor 34' to determine stack weight can also be seen in FIG. 10. By the two horizontal lines drawn through 5 volts and 4.9 volts in the graph, it can be seen that six sheets of 13 lb. bond paper (line G), four sheets of 20 lb. bond paper (line F), or two sheets of 110 lb. index stock (line E) each cause the analog stack height sensor to transmit the same amount of voltage change to the computer. Regardless of the number of sheets, if the computer calculates that the analog sensor voltage is changing at the rate of so many sheets per volt, multiplying the value of sheets per volt times the initial analog sensor voltage determines the number of initial sheets, or the total number of sheets in the stack and thus allows the calculation of the total weight of the stack. This can be done within just a few feed cycles at the beginning of reproduction of the document sheet stack, then updated at mid-stack or at the end of the reproduction cycle for the stack. Referring again to FIG. 2, as a document sheet is fed from the hopper 18, it passes beyond air jet assembly 30 where its lead edge is captured by the transport belt 50 entrained in part about wheel 52 (the transport belt and wheel arrangement may include multiple belts and corresponding wheels positioned in spaced relation along the longitudinal axis L 1 of wheel 52). The belt 50/wheel 52 arrangement defines a sheet travel path between the hopper 18 and the platen 14 of the reproduction station of apparatus 10. As the lead edge of the sheet is captured, it passes across a lead edge fed sensor 54. This tells the reproduction apparatus computer that the sheet has been successfully fed and that the vacuum applied to the plenum 28 (and thus feed belts 26) can be turned off. The drive for the feed belts 26 continues so that the belts do not present a frictional drag on the sheet; and the drive for the feed belts 26 is turned off after the trailing edge of the document sheet has passed the area of such belts. At that time, vacuum is re-established in the plenum 28 so as to cause the next document sheet (now the new bottommost document sheet of the stack) to adhere to the belts 26 to ready such sheet for feeding in the proper timed sequence. However, such sheet is not yet drawn into the stream of the sheet travel path because the belts 26 are stationary. Meanwhile, the first document sheet is fed by transport belt 50 and continues its travel around wheel 52. In the case of simplex copying, since only the front side of the respective document sheets are to be copied, the document sheet is directed onto the platen 14 past platen entrance sensor 56. The document sheet is driven by transport belt 50 until the lead edge is adjacent apertured platen drive belts 60. The platen drive belts 60 are entrained about rollers 62, and are selectively driven in a closed loop path in the direction of the associated arrow with the lower run of the belts in juxtaposition with the platen 14. A multi-chamber vacuum plenum 64 is located within the closed loop path and has a ported lower surface so as to operatively communicate with the lower run of the apertured platen drive belts 60. Accordingly, with vacuum applied to both chambers 64a and 64b of the plenum 64, the belts 60 effectively grasp the document sheet and transport it across the platen 14. At an intermediate point in the travel of the document sheet across the platen, the speed of the platen drive belts 60 is slowed so that as the sheet is brought into contact with a lead edge registration gate 66, the sheet does not strike the gate with such force as to damage its leading edge. Additionally, vacuum to the first camber 64a of the multi-chamber plenum 64 is turned off, leaving only the vacuum applied to the second chamber 64b and the portion of the belts 60 nearest the lead edge of the sheet at registration gate 66. After the lead edge of the document sheet has been registered against the gate 66, the document sheet is registered in a cross-track direction (transverse to the sheet travel path) by a cross-track registration mechanism 70. As best shown in FIG. 7, the mechanism 70 includes a first solenoid 72 which when actuated rotates a pivotable crank arm 74 to cause a foot 76 to lower against the platen 14. This establishes a registration edge for the front marginal edge of the document sheet (the edge nearest the operator). The registration edge defines a position for the document sheet where the image of information contained on the document sheet can be properly and consistently reproduced on an aligned receiver sheet in the reproduction apparatus 10. A second solenoid 78 of the cross-track registration mechanism 70 is actuated after the foot 76 engages the platen 14. The second solenoid 78 rotates a pivotable rocker arm 80 to bring a rotating wheel 82 down onto the document sheet. The rotating wheel 82 moves the document sheet laterally across the platen 14 (transverse to the direction of travel of the document sheet about the closed loop path from the hopper 18 to the platen 14 and back to the hopper) until the front marginal edge of sheet is registered against the foot 76. The solenoid 78 thereafter effects raising of the rotating wheel 82 so as to not disturb the registered sheet. After the document sheet has been properly registered at the gate 66 and against the foot 76, the reproduction apparatus 10 exposes the sheet in any well known manner to obtain an image of the information contained on the sheet. Subsequent to exposure of the document sheet, the lead edge registration gate 66 is lowered to a remote position out of the document sheet travel path, and platen drive belts 60 are allowed to transport the sheet off the platen 14. The document sheet is then directed into engagement with transport belt 90 and wheel 92 which capture the sheet and carry the sheet around the wheel 92 (in a manner similar to the transport effected by the transport belt 50 and wheel 52) defining a travel path between the platen 14 and the hopper 18. The normal document sheet travel path from hopper 18 via belt 50/wheel 52 to platen 14 assures that the top (information bearing) face of the document sheet will be placed face down on the platen 14. Thereafter, return of the document sheet from its face down orientation on the platen 14 via belt 90/wheel 92 to the hopper 18 will always return the document with a face up orientation in the hopper. The return of document sheets to the hopper 18, for proper restacking on the stack S supported on the surface 18a, is assisted by a driven nip roller assembly 140. The nip roller assembly, located downstream of the belt 90/wheel 92 (in the direction of document sheet travel), maintains control of respective document sheets until they are well into the area over the stack S. Further, at least one flexible strip of material 142 (commonly referred to as a dangler) intercepts the travel path of the returning document sheets exiting from the nip roller assembly 140. The strip 142 urges the returning document sheets downwardly toward the stack. However, it takes some time for a document sheet to settle on the stack in the hopper 18. With the rapid operational characteristics for the recirculating document feeder 12 according to this invention, it is necessary to assure rapid settling to prevent misfunction of the feeder operation, such as for example the return of the set count assembly finger 32a prior to settling of the initial topmost document sheet on the stack. Accordingly, an air jet assembly 144 is provided. The air jet assembly directs pressurized air from above the document sheet travel path toward the stack S downstream (in the direction of document sheet travel) of the flexible strip 142. The positive air pressure acts on the returning document sheets to cause the respective sheets to be expeditiously restacked with the least amount of resettling time The recirculating document feeder 12 according to this invention is constructed in a particularly described manner to selectively turn document sheets over whereby information contained on both sides thereof can be imaged in proper sequence by the reproduction apparatus 10. Accordingly, the apparatus 10 can accomplish duplex copying or simplex copying from duplex document sheet stacks, while maintaining the document sheets in face up order in the hopper of the recirculating document feeder 12 to enable an operator to always be able to see such face. With a document sheet stack of duplex documents (i.e., documents which contain information on both the front and back sides thereof), in order for the finished reproduction sets to be in proper sequential order, alternating reproduction cycles image the back side of each document sheet in the stack and then the front side of each document sheet. The respective cycles for imaging of the front sides of the document sheets is carried out in the manner described above. On the respective alternate cycles, when it is desired to image the back sides of the document sheets, a document sheet is fed from the hopper 18 by the document sheet removal device 24 described above, and progresses across the top of diverter 100 to be captured by belt 50 and wheel 52. As the trailing edge of the document sheet passes the sheet fed sensor 54, belt 50 and wheel 52 are stopped by a clutch/brake assembly (not shown). Diverter 100 is then rotated slightly counter clockwise to its phantom line position in FIG. 2, into intercepting relation with the document sheet travel path, and belt 50 and wheels 52 are driven to rotate in a reverse direction. Accordingly, the captured document sheet is transported in a reverse direction and directed by the diverter 100 into a secondary travel path P S1 . When in the secondary travel path P S1 , the document sheet is detected by the platen entrance sensor 56 as it is transported onto platen 14. The signal from the sensor 56 to the reproduction apparatus computer causes the sequence of platen transport events described above to be carried out in the manner described above. The transport of the document sheet through the secondary travel path P S1 effects an inversion of the document sheet so that the back side thereof is face down on the platen 14 for imaging of the information contained thereon. Meanwhile, as the trail edge of the document sheet passes the platen entrance sensor 56, diverter 100 is returned to its normal (solid line) position, the direction of drive for the belt 50 and wheel 52 are reversed (to their initial drive direction), and the drive belts 26 are readied to accept another document sheet feed command. After the back side of the document sheet has been imaged, registration gate 66 is lowered, platen drive belts 60 are actuated to drive the document sheet off the platen 14, and the document sheet is transported to the belt 90 and wheel 92 for capture thereby. However, if such document sheet were allowed to proceed in the travel path described above, the sheet would end up in hopper 18 with its front side (originally upwardly oriented face) oriented downwardly. This condition would cause confusion for the operator and would place the document sheets in an improper page sequential order. In order to overcome these problems and return the document sheet to the hopper 18 in its original first side face up orientation, return sensor 102 detects the lead edge of the document sheet and provides an appropriate signal for the reproduction apparatus computer. Such signal causes the diverter 104 to be rotated slightly counter-clockwise to its phantom line position in FIG. 2, into intercepting relation with the document sheet travel path, and the direction of drive for belt 90 and wheel 92 to be reversed through a clutch/brake (not shown). The document sheet is thus directed to proceed through a secondary travel path P S2 . As the trailing edge of the document sheet passes the platen exit sensor 106, the sensor detects the sheet and provides an appropriate control signal for the computer. In response to such control signal, the diverter 104 is returned to its normal (solid line) position where it is ready for directing travel of the next document sheet. Meanwhile, the document sheet proceeds along the secondary travel path P S2 back into hopper 18, and completion of the feed cycle for such sheet is determined by the return sensor 102 which detects the trailing edge of the sheet. This process is repeated for each document sheet in the stack, and for the number of times equal to the operator selected desired number of reproductions of the document stack. An important aspect of the recirculating document feeder 12 according to this invention is the use of an adaptive timing control of the various transport elements of the feeder as opposed to a strict fixed time sequencing of events. This has been found to be necessary since experience has shown that the physical characteristics of the document sheets varies not only from brand to brand, but from sheet to sheet, even within the same ream. It is natural, therefore, to expect that the passing of a sheet over mechanical devices that induce drag, frictional forces and other influences can present different timing effects on each sheet even if all document sheets of a stack are created from paper from within the same ream. Moreover, the individual document sheets of a stack may not all be the same kind, brand, weight or texture. With the high transport speeds necessary in modern reproduction apparatus including a device such as the recirculating document feeder 12, individual events occur during extremely short time intervals, for example on the order of a few milliseconds each. A fixed timing controller which follows a definitive program to turn on and off clutches, pressurized air and vacuum valves, solenoids, etc., can hardly be expected to present an optimum set of operating conditions for each individual sheet in a stack. In order to control the sequence of events and to maximize the reliability of the recirculating document feeder 12 and its individual elements, a more individualistic operational approach is utilized. The sensors that control the timing of individual events are best shown in FIG. 2. Sensor 54 detects that a document sheet has actually been fed from the hopper 18 sufficiently for the transport belt 50/wheel 52 to capture and control the transport of the sheet. Platen entrance sensor 56 detects that the document sheet has properly negotiated the turn about the wheel 52 and is progressing toward the platen 14. As the lead edge of the document sheet is detected by the platen entrance sensor 56, the reproduction apparatus computer effects establishment of the vacuum levels in the multi-chamber plenum 64 and sets the appropriate speed of the transport belts 60. As the trail edge of the document sheet is detected by the platen entrance sensor 56, the drive for the transport belts 60 is adjusted to start slowing down the belts to a second appropriate speed so as to prevent lead edge damage as the document sheet is registered at the gate 66. Platen exit sensor 106 detects that the document sheet has actually left the platen 14 and effects an increase in the velocity of the belts 60 to transport the sheet off the platen as quickly as possible. As the trail edge of the document sheet is detected by the platen exit sensor 106, a control signal to the computer indicates that the document sheet has been captured by the transport belt 90/wheel 92 sufficiently to be the sole transporting mechanism for the document sheet, and that the gate 66 can be returned to its travel path intercepting position in readiness for registration of the next document sheet. Return sensor 102 detects that the document sheet is returning to the hopper area as the lead edge of the sheet is detected, and that the sheet has completely left the transport belt 90/wheel 92 as the trailing edge of the sheet is detected by such sensor. In the mode of operation for handling duplex document sheets, all of the described events become more important when the action of the reversal clutch/brakes and travel path diverters are brought into play. Upon the detection of the trail edge of a document sheet by the fed sensor 54, such sensor provides a signal for the computer to indicate that the document sheet is clear of the diverter 100 and that it is safe to move such diverter to its phantom line position. When the document sheet travel is then reversed by actuation of a clutch/brake to reverse direction of the transport belt 50/wheel 52, the document sheet can enter properly into the secondary travel path P S1 . As the trail edge of the document sheet is detected by the platen entrance sensor 56, the diverter 100 can be allowed to return to its solid line position in preparation for directing the next document sheet. Likewise, as the trail edge of the document sheet is detected by the platen exit sensor 106, an appropriate signal to the computer indicates that it is safe to move the diverter 104 to its phantom line position so that the document sheet, on reversed travel, can enter into the respective secondary return travel path P S2 . The times of the document sheet transport events is monitored as each document sheet progresses around the travel path from hopper 18 to platen 14 and back to the hopper. Comparing the nominal estimated times for these events with the actual times enables the computer to decide, based on experience criteria, to allow the document sheet transportation cycle (and thus the reproduction cycle) to continue, or to stop the sheet transport entirely in order to prevent a jam condition from causing damage to the document sheet. Additionally, the individual sheet timing measurements can be used to alter the velocity of travel path transport belts, rollers and drives so as to correct the document sheet travel velocities in various portions of the travel path and bring them back to a nominal condition. This sort of adaptive timing will enable the recirculating document feeder 12 to accommodate for things like excessive friction buildup in drive shafts, bearings and the like, or for loss of sheet velocity because of slippage on frictional surfaces. Within reason, adjustments can be made in the velocities of drive shafts, as long as there is a limit to the amount of adjustment correction imposed. That is, a certain amount of speed correction is employed in conjunction with statistical data collection and analysis that points to diverse occurrences such as potential bearing seizures, friction surface changes and the like, which are communicated to service personnel to indicate that certain mechanical or electrical components are in need of replacement or other attention. As another aspect of the recirculating document feeder 12 according to this invention, such feeder is constructed to enable an operator to introduce a single sheet onto the platen without having to place it in the hopper 18. As shown in FIG. 8, a document sheet D is placed on a work surface 110 of the reproduction apparatus 10 adjacent to the feeder 12. The document sheet is manually urged into the feeder 12 until the sheet intercepts a document present sensor 122. This action signals the feeder to complete its present reproduction cycle, reverse the direction of transport belt 50/wheel 52, and to actuate solenoid 114 which pulls cam lever 116 so as to raise plate 118. Raising the plate 118 brings roller 120 into engagement with belt 50 to capture the document sheet D between roller and the belt, and transport the sheet forward (toward the left in FIG. 8) until it strikes gate 122. Since the document sheet is being constantly urged against the gate 122 by the belt 50, any skew in the document sheet is corrected by alignment of the sheet with the gate. At an appropriate time, solenoid 124 is actuated to raise gate 122, allowing the properly aligned document sheet to proceed onto the platen 14. The document sheet is transported across the platen 14 by belts 60 up to gate 66 where sheet alignment is corrected a second time if necessary. After the reproduction apparatus 10 has captured an image of information contained on the document sheet, gate 66 is lowered, diverter 104 is moved to its phantom line position, and the document sheet is transported off the platen 14 into a collection hopper 126 (shown in FIG. 1). Successive document sheets can be introduced into the recirculating document feeder 12 in a like manner. The recirculating document feeder 12 according to this invention can also be used in a manual mode. For manual mode use, the operator lifts the feeder about its pivot connection with the reproduction apparatus 10 and places a document on the platen 14. The feeder is then returned to its closed position if the document has no substantial thickness (i.e., a sheet of paper), or remains in the partially raised position in the instance where the document is a book or solid object while the reproduction apparatus makes a reproduction. Moreover in the manual mode for the recirculating document feeder 12, the reproduction apparatus 10 can be used to make reproductions of continuous computer forms (fan-fold sheets). A tractor drive mechanism (not shown) is attached to the reproduction apparatus to pull the continuous computer forms across the platen 14 under the recirculating document feeder in its closed position without having to thread the forms through any part of the feeder. Further, the recirculating document feeder can be raised or closed without disturbing the continuous computer forms path. Another aspect of the recirculating document feeder according to this invention is to provide a constant gap between the base plate 130 and the platen 14. Since document sheets must pass through this gap in their travel across the platen, this spacing is a critical parameter. That is, if the gap is too large, the document sheet may not properly register at the gate 66 and foot 76 and may be held out of the depth of focus for the imaging system of the reproduction apparatus 10; on the other hand, if the gap is too small, the document sheet may jam between the base plate and the platen. The base plate 130, supported in the housing 16 of the recirculating document feeder 12, carries the platen transport belts 60 (and associated multi-chamber vacuum plenum 64) and the cross-track registration assembly 70. The support for the base plate 130 includes springs 132 urging the base plate in a direction toward the platen 14 when the recirculating document feeder 12 is in operative relation with the reproduction apparatus 10. Accordingly, the base plate 130 will "float" relative to the remainder of the recirculating document feeder when the feeder is lifted off the platen, but will come to rest against fixed spacer pads 134 when the feeder is in operative association with the reproduction apparatus. The spacer pads 134 accurately determine the spacing between the base plate and the surface of the platen. With this described spacer pad arrangement, there are no adjustments necessary to guarantee the spacing between the base plate and the platen during operative association of the recirculating document feeder with the reproduction apparatus. In addition, since the vacuum to the belts 60 is effective in this constant predetermined gap, air flow characteristics passing through this space are guaranteed to be more stable and determinant from one recirculating document feeder to another since the flow is effective in a fixed space rather than a variable space that would result from differing adjustments. The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

An improved recirculating document feeder for presenting sheets from a document sheet stack individually to a station of the reproduction apparatus for reproducing of information contained on such sheets. The improved recirculating document feeder comprises a housing containing a support for a document sheet stack. A feed path extends away from and then back to the document stack support, for directing sheets from the support into association with the reproducing station and then back to the stack. Document sheets are selectively fed from the stack seriatim about the feed path. The feed for the document sheets includes a transport assembly overlying at least a portion of the reproduction apparatus station. The transport assembly is mounted for movement relative to the housing, and engageable by a spacer associated with the reproduction apparatus station for self-adjustment of the transport assembly in the mount to locate the transport assembly a predetermined distance from the reproduction apparatus station irrespective of the position of the housing relative to said reproduction apparatus station.

FIELD OF THE INVENTION This invention relates to confection holding devices, and more particularly relates to a symmetrically shaped holding device which is suitable for automatic mechanical insertion within a conical container. DESCRIPTION OF THE PRIOR ART It has long been known to utilize rigid holding sticks of plastic or wood to support confections, such as ice cream or the like. In addition, it has become popular to provide a plastic statuette on one end of the confection holding device to hold the confection and to serve as a prize for the consumer. Such a confection holding device including a plastic statuette, is described in U.S. Pat. No. 3,085,883, issued Apr. 16, 1963. However, such prior confection holding devices which include statuettes have been time consuming and expensive to insert into confection containers, inasmuch as care must be taken to orient the statuettes within the containers in the desired position. The corrrct orientation of the statuette within a conical container has thus heretofore been achievable only through time consuming and laborious manual insertion. Moreover, such pior confection holding devices which include statuettes present a risk of injury to the mouth of the consumer, due to the irregular and sharp shapes of the statuettes which are hidden by the confection. A need has thus arisen for a confection holding device which automatically orients itself in a confection container when mechanically inserted, thereby resulting in a substantial savings in time and money over devices in the prior art. In addition, there is a need for a confection holding device which substantially reduces a consumer's risk of harm from mouth injuries caused by the shape of the holding device. SUMMARY OF THE INVENTION The present invention provides a symmetrical confection holding device offering a savings in time and money in its capability of automatically orienting itself upon mechanical insertion within a conical container, and a holding device which reduces the consumer's risk of harm from such an object. In accordance with the present invention, a symmetrical holding device for a confection is positioned within an open ended conical container. The holding device has a central body portion with an annular surface of smaller circumference than that of the open end of the container, thereby enabling the annular surface of a central body to engage the inner surface of the container when positioned within it. The positioning of the holding device within the conical container thus divides it into first and second chambers, separated by the central body of the holding device. In accordance with another aspect of the invention, the holding device has first and second elongate members extending perpendicularly from opposite sides of the annular surface of the central body. The elongate members are symmetrical about the annular surface of the central body. The first elongate member extends into the first upper chamber and the second elongate member extends into the second lower chamber, when the holding device is positioned within the conical container. The central body and first elongate member supports confection placed within the first chamber. The second elongate member, segregated from the confection by the seal of the central body, serves as a holding devive for supporting the confection when the conical container is removed. BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and further objects and advantages thereof, reference is now made to the following description taken in conjunction with the following drawings: FIG. 1 is a perspective view of the preferred embodiment of the invention; FIG. 2 illustrates a system for mechanically inserting the invention into an open ended conical confection container; FIG. 3 is a side view of the preferred embodiment of the invention in an empty open ended conical confection container; FIG. 4 is a side phantom view of the preferred embodiment of the invention positioned within an open ended conical container filled with a confection; FIG. 5 is a perspective view of an alternate embodiment of the invention; and FIG. 6 is a perspective view of still another embodiment of the invention. DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a perspective view of the preferred embodiment of the present holding device, generally identified by the numeral 10. Elongate members 12 and 14 integrally extend from opposite sides of a central body portion 16, which is shaped as a circular disk. Elongate members 12 and 14 are symmetrical about and perpendicular to the annular surface 18 of central body portion 16. Elongate member 12 has a circular cross section throughout its length and has an upper relatively small diameter end 22 and a periphery which curves outwardly to a relatively large diameter lower portion integrally attached to central body 16. Elongate member 12 is connected by beveled annular surface 24 to its end 22. Elongate member 14 has a circular cross section throughout its length and has a relatively small diameter end 23 and a periphery which curves outwardly to a relatively large portion integrally attached to central body portion 16. Elongate member 14 is connected to end 23 by a beveled annular surface 25. An important advantage of the confection is the substantial reduction in risk of injury to the mouth of the consumer. The periphery of elongate members 12 and 14 curving outwardly from their respective ends 22 and 23 conform more readily to the mouth than an irregularly and unknown shaped statuette. All the confection may be removed from the periphery of elongate member 12 without encountering any irregular shape or sharp object which might harm the consumer. FIG. 2 illustrates a system for automatically mechanically inserting the invention 10 in an open ended conical container 30. The system consists of a mechanical apparatus, generally referred to by numeral 80, for storing and discharging one symmetrical holding device 10 into an open ended conical container 30 moving beneath the mechanical apparatus 80 on conveyor 100 powered by electrical motor 102. Electrical motor 102 is synchronized with discharge release motor 98 on mechanical apparatus 80 by a control unit 104. The mechanical storage/discharge unit 80 has an elevated hopper 82 for storing a plurality of symmetrical holding devices 10 in random orientations. Pressure plate 84 is positioned within elevated hopper 82 above a circular opening 88 in hopper 82. Agitator 86 is a rigid member attached to pressure plate 84 and rotates directly above opening 88. Agitator 86 is powered by a small electrical motor 87 positioned within pressure plate 84 and moves holding devices above circular opening 88. Electrical motor 87 is connected to an outside power source through the walls of hopper 82. Agitator 86 provides a continuous flow of holding devices 10 from hopper 82 through opening 88. Hopper opening 88 feeds holding devices 10 into the discharge unit 90. Holding devices 10 pass through the circular opening 88 into cylindrical tube 92 which has a circumference larger than that of annular surface 18 of central body portion 16. Symmetrical holding device 10 passes by gravity from opening 88 to discharge release mechanism 94 with elongate members 12 and 14 in the vertical plane within cylindrical tube 92. Discharge release mechanism 94 consists of an eccentric wheel energized by electric motor 98 synchronized through control 104 to conveyor motor 102. The discharge release mechanism 94 operates to maintain those holding devices 10 within cylindrical tube 92 while releasing a single holding device 10 to spring operated trap door 96 for release into open end of conical container 30 positioned beneath trap door 96 by conveyor 100. Symmetrical holding device 10 automatically aligns itself upon dropping within conical container 30. This container 30 moves by conveyor 100 for the filling of the upper part of the conical container 30, defined by central body portion 16, with a confection such as ice cream or the like. The annular surface 18 of central body portions 16 snugly engages the inner walls of conical container 30 to provide a seal for the confection. It will of course be understood that the holding devices may be dropped into the containers 30 by any suitable conventional dispersing method. FIG. 3 is a side view of a symmetrical holding device 10 positioned within an empty open ended conical container 30. The circumference of the annular surface 18 of central body portion 16 is less than the circumference of the annular base 32 of conical container 30, thereby allowing holding device 10 to be positioned within container 30. Holding device 10 engages the inner surface of conical container 30 where the circumference of annular surface 18 is equal to the inner circumference of the conical container 30. Central body portion 18 divides conical container 30 into first upper chamber 38 and second lower chamber 39. The upper chamber 38 is defined by the open end of conical container 30, the inner walls of conical container 30 up to the point where central body portion 16 engages the conical container 30, and the upper portion of central body portion 16 itself. The lower chamber 39 is defined by the opposite portion of central body portion 16 and the inner surface of conical container 30 extending from where central body portion 16 engages the surface of conical container 30 to the apex portion 34 of the conical container 30. Elongate member 12 extends into upper chamber 38 and elongate member 14 extends into lower chamber 39. The beveled annular surface 25 engages the inner surface of conical container 30 at a point where the circumference of the beveled annular surface 25 is equal to the circumference of the annular surface of conical container 30. The engagement of symmetrical holding device 10 with the inner surface of conical container 30 by the central body portion 16 and beveled annular surface 25 automatically maintains the annular surface 18 of central body portion 16 perpendicular to the central axis 31 of conical container 30. The snug engagement of annular surface 18 with the inner walls of conical container 30 also serves to act as a seal to prevent the leakage of confection from the bottom of upper chamber 38 into lower chamber 39 and from the bottom of container 30 itself. FIG. 4 is a side phantom view of symmetrical holding device 10 positioned within a conical container 30 filled with confection 50, such as ice cream, flavored ice, or the like. Confection 50 seals upper chamber 38 and an area above the open end of conical container 30. Confection 50 is supported by the inner walls of conical container 30, elongate member 12 extending in the upper chamber 38, and central body portion 16. Elongate member 14 is positioned within lower chamber 39 which contains no confection, since central body portion 16 seals confection from lower chamber 39. Upon removal of conical container 30, the confection is supported by elongate member 12 and central body portion 16. The curved periphery of elongate member 14 may be grasped between the thumb and forefinger of the consumer to hold the confection in position during its consumption. FIG. 5 illustrates an alternate embodiment of a symmetrical holding device generally identified by the numeral 40. Symmetrical holding device 40 consists of a central body portion 46 shaped as a thin circular disk. Central body portion 46 has an annular surface 48 for engaging the inner walls of conical container 30. Elongate members 42 and 44 are symmetrical about and perpendicular to the annular surface 48 of central body portion 46. Elongate members 42 and 44 are shaped as hexagonal rods of relatively small uniform cross section throughout the length of each. The hexagonally shaped rods provide a rigid structure as a means for elongate member 42 to support confection and for elongate member 44 to be grasped between the thumb and forefinger as a handle. The hexagonal shape of the rod reduces slippage of the handle in the hand of the consumer. Elongate members 42 and 44 have ends 52 and 53, respectively, with hexagonal cross section. FIG. 6 is another alternate embodiment of a symmetrical holding device generally identified by the numeral 60. The central body portion 66 is a sphere with annular surface 68 around the middle of the sphere for engaging the inner surface of conical container 30. Elongate members 62 and 64 are symmetrical about and perpendicular to the annular surface 68 and are integrally attahed to sphere 66. Elongate members 62 ad 64 are shaped as cylindrical rods of uniform cross section. Elongate members 62 and 64 have circular ends 72 and 74, respectively. It will be understood that devices may be constructed from any suitable material, but preferably made from plastic. It will be further understood that an elongate member may vary in cross sectional shape, or it may be of non-uniform cross section throughout its length. Although preferred embodiments of the invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed, they are capable of numerous rearrangements, modifications, and substitutions of parts and elements without departing from the spirit of the invention.

The specification discloses a confection holding device having a central body with an annular surface and two rigid symmetrical elongate members integrally attached to and perpendicularly extending from opposite sides of the central body. The symmetry of the holding device allows it to be mechanically inserted in a conical container without regard to its orientation. The annular surface of the central body engages the inner walls of a conical container, defining an upper chamber into which a confection may be placed. The central body and the upper elongate member support the body of a confection when the conical container is removed. The lower elongate member is held by the consumer as a handle to support the confection during consumption.

FIELD OF THE INVENTION AND RELATED ART [0001] The present invention relates to an image forming apparatus, for example, an electrophotographic copying machine, an electrophotographic printer, etc. It also relates to a developing apparatus usable for an image forming apparatus such as the abovementioned ones. [0002] An electrophotographic image forming apparatus forms an electrostatic latent image on its image bearing member, and develops the electrostatic latent image into a visible image, that is, an image formed of toner, with its developing apparatus. There have been proposed dry developing apparatuses which use a developer made up of a single component, and also, dry developing apparatuses which use a developer made up of two components. Further, some of them have been put to practical use. Hereafter, the former may be referred to as a single-component developing apparatus, whereas the latter may be referred to as a two-component developing apparatus. [0003] From the standpoint of reliability with which toner is charged, and also, from the standpoint of durability of toner, a developing apparatus, which uses a two-component developer, more specifically, a developer made up of toner, and magnetic carrier which contributes to the charging of the toner, is superior to a developing apparatus which uses a single component developer. Thus, a developing apparatus which uses a two-component developer is widely used as the developing device for an image forming apparatus which is required to be significantly more durable and higher in image quality than an ordinary image forming apparatus. In order to ensure that a developing apparatus is stable in performance in terms of the development of a latent image on an image bearing member, it is necessary to ensure that the developing apparatus is stable in the amount (preset amount) by which developer is placed in a layer on its development sleeve, that is, its developer bearing member. Thus, a developing apparatus is provided with a development blade, which is a member for controlling the amount (preset amount) by which developer is allowed to remain in a layer on the peripheral surface of the development sleeve. In terms of the direction in which a photosensitive drum, which is the latent image bearing member of an image forming apparatus, is rotated, the development blade is disposed on the upstream side of the developing position, which is the position where the distance between the photosensitive drum and development sleeve is smallest. However, a developing apparatus structured as described above suffers from the problem that when the developer in the developing apparatus is in a certain condition, toner particles 47 ( FIG. 8 ) having separate from carrier particles are likely to agglomerate and adhere to the development blade (developer regulating member. If toner particles agglomerate into a lump 46 of toner particles and adhere to the development blade ( FIGS. 7 and 8 ), the amount by which developer is allowed to remain on the development sleeve (developer bearing member) becomes unstable, resulting sometimes in the formation of an image which is abnormal in density. [0004] In particular, as developer increases in the weight ratio of the toner therein, it increases in the ratio of the nonmagnetic toner to the magnetic carrier, making it impossible for the magnetic carrier to retain all the nonmagnetic toner. In other words, the developer increases in the amount of so-called free toner. Further, with the increase in the length of time the developing apparatus is used for development, the toner reduces in the amount of the external additives which are on the surface of each toner particles; the deteriorated toner increases. [0005] Thus, various solutions for the above-described problem have been proposed. One of the proposals is disclosed in Japanese Laid-open Patent Application H09-106179. According to this proposal, the developer regulating member is given microscopic vibrations to prevent the toner from agglomerating on the development blade. Another proposal is disclosed in Japanese Laid-open Patent Application H05-346731, which relates to an image forming apparatus which uses a two-component developer. According to this patent application, in order to recover the developer on the portion of the development sleeve, which is facing the photosensitive drum after the completion of the development of a latent image, the developing apparatus is structured so that while an image is not formed, the development sleeve is rotated in the opposite direction from the direction in which it is rotated for latent image development. [0006] However, the structural arrangement disclosed in Japanese Laid-open Patent Application H09-106179 requires an electric power source dedicated to the microscopic vibrations of the developer regulating member. Thus, it increases the developing apparatus in component count, increasing thereby the developing apparatus in cost. Further, the structural arrangement disclosed in Japanese Laid-open Patent Application H05-346731 is simply for recovering the developer on the development sleeve into the developing device itself, being therefore not satisfactory to prevent the toner agglomeration on the development blade. SUMMARY OF THE INVENTION [0007] Thus, the primary object of the present invention is to provide an image forming apparatus which uses two-component developer, more specifically, developer made up of magnetic carrier and nonmagnetic toner; is simple in structure; and yet, does not output a defective image, the defects of which are attributable to the adhesion of lumps of toner particles resulting from the agglomeration of the toner particles, to the regulating member for regulating in thickness the toner layer on the peripheral surface of the developer bearing member. [0008] According to an aspect of the present invention, there is provided an image forming apparatus comprising an image bearing member for bearing an electrostatic latent image; a rotatable developer carrying member, provided opposed to said image bearing member, for carrying a developer including toner and a carrier to a position where said developer carrying member is opposed to said image bearing member; a regulating member for regulating the amount of the developer to be carried on said developer carrying member; a driving device for rotating said developer carrying member; a controller for controlling said driving device to execute, at the time of end of image formation, a plurality of continuous operations each including acceleration of a rotational speed of said developer carrying member and deceleration thereof following the acceleration. [0009] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0010] FIG. 1 is a schematic sectional view of the image forming apparatus in the first preferred embodiment of the present invention. [0011] FIG. 2 is a graph showing the relationship among the toner density, degree ratio of agglomeration, and frequency with which an image suffering from abnormal white vertical streaks is formed. [0012] FIG. 3 is a graph showing the relationship between the cumulative number of images (copies) made and the ratio of toner agglomeration. [0013] FIG. 4 is a schematic sectional view of the developing device. [0014] FIG. 5 is a schematic top plan view of the developing device driving mechanism. [0015] FIG. 6 is a diagram for describing the intermittent microsecond driving of the development sleeve. [0016] FIG. 7 is a schematic sectional view of the developing device after the agglomeration of the toner on the development blade. [0017] FIG. 8 is a schematic drawing which depicts the agglomeration of the free toner particles. [0018] FIG. 9 is a flow chart of the image forming apparatus operation in the mode in which the development sleeve is intermittently driven for microseconds. [0019] FIG. 10 is a block diagram of the mechanism for intermittently driving the development sleeve for microseconds. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 [Overall Structure of Image Forming Apparatus] [0020] Referring to FIG. 1 , the image forming apparatus in this embodiment has four image forming portions Pa, Pb, Pc, and Pd, which are placed in tandem in a straight line. The image forming portions Pa, Pb, Pc, and Pd are roughly the same in structure. Thus, their structure will be described referring to the image forming portion Pa. [0021] The image forming portion Pa is provided with a photosensitive drum la (image bearing member). It is also provided with a corona-based charging device 2 a, an exposing apparatus 3 a (exposing means), a developing apparatus 4 a (developing means), a transfer roller 53 a (transferring means), and a cleaning blade 6 a (cleaning means), which are disposed in the adjacencies of the peripheral surface of the photosensitive drum 1 a, in the listed order in terms of the direction (indicated by arrow mark) in which the photosensitive drum 1 a is rotated. [0022] Four toner images formed by the image forming portions Pa, Pb, Pc, Pd are transferred in layers onto an intermediary transfer belt 51 , and then, are transferred together onto a sheet of recording medium P by a secondary transfer roller 57 (transferring means). Located on the immediately downstream side of the secondary transfer roller 57 in terms of the direction in which the recording medium P is conveyed is a fixing apparatus 7 (fixing means). [Photosensitive Drum (Image Bearing Member)] [0023] The image forming apparatus in this (first) embodiment is provided with the photosensitive drum 1 (image bearing member), which is an electrophotographic photosensitive member in the form of a rotatable drum. The photosensitive drum 1 is provided with a photosensitive layer formed of an OPC (organic photosensitive semiconductor), which is negative in default polarity. The photosensitive drum 1 is 84 mm in diameter, and is rotated about its axial line (unshown) in the direction indicated by an arrow mark at a process speed (peripheral velocity) of 300 mm/sec. The photosensitive drum 1 is made up of an electrically conductive substrate and three functional layers, more specifically, an undercoat layer, a charge generation layer, and a charge transfer layer. The substrate is in the form of a drum. The three functional layers are coated in layers on the peripheral surface of the substrate, in the listed order. The under coat layer is for suppressing optical interference, and also, for preventing the upper layers from separating from the substrate. Among the three functional layers, the charge generation layer and charge transfer layer make up the photosensitive layer. [2] Charging Apparatus [0024] The image forming apparatus shown in FIG. 1 has charge rollers 2 ( a - d ) as charging means. It also has voltage applying means (unshown) for applying voltage to the charge rollers 2 . The charge rollers 2 are members for uniformly charging the peripheral surface of the photosensitive drum 1 to preset polarity and potential level across the portion which is in the preset area. In this embodiment, the voltage applying means is controlled so that the peripheral surface of the photosensitive drum 1 is uniformly charged to 600 V. [3] Exposing Apparatus (Information Writing Means) [0025] The image forming apparatus depicted in FIG. 1 is provided with exposing apparatuses 3 ( a - d ), which are the information writing means for forming an electrostatic latent image on the charged photosensitive drum 1 . Each exposing apparatus 3 in this embodiment is a laser beam scanner which uses a semiconductor laser. The exposing apparatus 3 outputs a beam of laser light while modulating the beam of laser light with the image formation signals sent to the main assembly of the image forming apparatus from an image reading apparatus (unshown) or the like. More specifically, the beam of laser light is moved in the manner to scan the peripheral surface of the photosensitive drum 1 , which has just been charged and is being rotated, at the exposing position. Thus, numerous points of the uniformly charged area of the peripheral surface of the photosensitive drum 1 reduce in potential level. As a result, an electrostatic latent image, which reflects the abovementioned information of an image to be formed, is effected on the peripheral surface of the photosensitive drum 1 . [4] Developing Apparatus [0026] The developing apparatuses (devices) 4 ( a - d ), which are developing means, develop an electrostatic latent image on the photosensitive drum 1 into a visible image (toner image) by supplying the electrostatic latent image with developer (toner). The developing apparatus 4 in this embodiment is of the so-called magnetic brush type. That is, it uses a two-component magnetic developer. The image forming apparatus is structured so that multiple (four) electrostatic latent images can be developed with multiple (four) monochromatic toners, different in color, one for one. Next, referring to FIG. 4 , the developing apparatuses 4 in this embodiment will be described in more detail. [0027] A developing means container 40 M has a development chamber 49 , in which developer is stored and stirred. Each developing apparatus 4 is provided with a development sleeve 45 M (developer bearing member), which is located across the opening of the development chamber 49 . The two-component developer in the development chamber 49 is a mixture of toner and magnetic carrier, and is stirred by a pair of developer stirring members 42 and 43 . The magnetic carrier used by the developing apparatus in this embodiment is roughly 10 13 Ω·cm in electrical resistance, and 40 μm in particle diameter. The toner is negatively charged by the friction between the toner and magnetic carrier. The toner used by developing apparatus in this embodiment is adjusted in cohesiveness with the use of external additives and/or by controlling the shape of toner particle; it has been adjusted to 40 degrees or so in cohesiveness. It has been known that if toner is excessively low in cohesiveness, it easily shifts, being therefore likely to cause an image forming apparatus to form an image which is defective in that it appears as if it were sprinkled with toner after its formation, an image which is defective in that it appears as if it were covered with polka dots (attributable to separative discharging of static electricity to image bearing member, or the like discharge), an image which is defective in that it has abnormal radial streaks. On the other hand, if toner is excessively high in cohesiveness, it also creates problems: for example, it creates problems while it is conveyed, or is likely to cause an image forming apparatus to forms an image, the center portion of which is missing as if it were eaten by moth or the like. [0028] The development sleeve 45 M, which is a developer bearing member, is positioned in parallel to the photosensitive drum 1 in such a manner that the shortest distance (S-Dgap) between the peripheral surface of the development sleeve 45 M and that of the photosensitive drum 1 is 350 μm. This area in which the distance between the photosensitive drum 1 and development sleeve 45 M is shorted is the development portion. The development sleeve 45 M is rotated in such a direction that its peripheral surface moves in the same direction as the moving direction of the peripheral surface of the photosensitive drum 1 . That is, the development sleeve 45 M is rotated in the direction indicated by an arrow mark C whereas the photosensitive drum 1 is rotated in the direction indicated by an arrow mark A. [0029] A part of the body of two-component developer in the developing means container 40 M is adhered and held to the peripheral surface of the development sleeve 45 M in a layer (magnetic brush layer) by the magnetic force of a magnetic roller 41 disposed within the development sleeve 40 M. Thus, as the development sleeve 45 M is rotated, the two-component developer on the peripheral surface of the development sleeve 45 M moves with the peripheral surface of the development sleeve 45 M. As the development sleeve 45 M is rotated, the magnetic brush layer is smoothed by a developer coating blade 44 into a thin and uniform layer of developer with a predetermined thickness. As the development sleeve 45 M is rotated further, this thin layer of developer comes into contact with the peripheral surface of the photosensitive drum 1 , and rubs the peripheral surface of the photosensitive drum 1 as it is moved through the development portion. [0030] To the development sleeve 45 M, a development bias is applied from an unshown electrical power source, while being controlled by a CPU 100 (controlling means). In this embodiment, the development bias to be applied during a normal image forming operation is set so that its DC component Vdc is −450 V, and AC component is 1.8 kVpp (it is blank pulse, and is 12 kHz in frequency). “Blank pulse” is such a pulse that each cycle is made up of a period in which both the AC and DC voltages are applied together, and a period (blank period) in which only the DC voltage is applied. As the development bias is applied to the development sleeve 45 M, the electrostatic latent image on the photosensitive drum 1 is developed into a visible image formed of toner (toner image). In the case of this embodiment, the toner is adhered to the exposed points (points illuminated by beam of laser light) of the photosensitive drum 1 ; that is, the electrostatic latent image is developed in reverse. [0031] To summarize, as the development sleeve 45 M is rotated, the developer in the developing means container 40 M of the above described developing apparatus 4 is coated in thin layer on the peripheral surface of the development sleeve 45 M, and is conveyed to the development portion, in which the toner in the developer on the peripheral surface of the development sleeve 45 M is adhered to the selected (exposed) points of the electrostatic latent image on the photosensitive drum 1 , by the electric field generated by the development bias applied to the development sleeve 45 M by the development bias application power source. [0032] The toner adhered to the photosensitive drum 1 is −25 μC/g in the amount of charge. [0033] The portion of the body of developer which was not used for the development is conveyed by the magnetic pole N 1 of the magnetic roller 41 back into the developing means container 40 M, and falls into (is recovered by) the developing means container 40 M due to its own weight, by the time it reaches the mid point between the magnetic poles N 1 and N 2 which are opposite is polarity. [0034] In this embodiment, in order to maintain the two-component developer in the developing means container 40 M (more specifically, development chamber 49 ) so that the toner density of the developer remains roughly in a preset range, a referential toner image (patch) is formed on the photosensitive drum 1 , during a period which is correspondent to one of the recording sheet intervals, with the development contrast Vcont set to a predetermined value. That is, the toner density of the two-component developer in the developing means container 40 M is detected by detecting the image of the patch (referential toner image) with the use of an optical toner density sensor (unshown), for example. If it is determined that the toner density is below the abovementioned proper range, a target level for the toner density ratio T/D is increased in value to increase the amount by which toner is supplied to the developing device 4 from the toner hopper (unshown toner supplying means). As the developing device 4 is supplied with a fresh supply of toner, the toner density ratio T/D increases, which in turns reduces, in the amount of charge, the toner in the developing device 4 . Thus, as the developing device 4 is supplied with a fresh supply of toner, a control is executed to keep constant the toner density relative to the preset development contrast Vcont. On the contrary, if it determined that the toner density is above the abovementioned proper range, the delivery of the toner to the developing device 4 is temporarily halted. Here, “development contrast Vcont” means the difference |Vdc−V 1 | between the potential level V 1 of the exposed areas of photosensitive drum 1 after the exposure of the charged photosensitive drum 1 for the formation of a latent image on the photosensitive drum 1 , and the potential level Vdct of the development sleeve 45 M. Regarding the method used for supplying the developing apparatus with toner, the developing apparatus 4 in this embodiment is supplied with such a developer that is a mixture of toner and magnetic carrier, and the old and excessive portion of the developer in the developing apparatus 4 is trickled out of the developing device through an unshown developer outlet with which the developing device is provided. [0035] Next, the method, in this embodiment, for detecting the toner density ratio T/D (ratio between toner and magnetic carrier) of the two-component developer in the development chamber 49 will be described. In this embodiment, the inductance detecting method is used to detect the toner density ratio T/D. The inductance detecting method determines the actual toner density ratio of the developer in the developing device by detecting the apparent magnetic permeability, which reflects mixing ratio between the magnetic carrier and nonmagnetic toner. The amount by which toner is to be supplied to the developing device is determined by the comparison of the detected toner density ratio with a referential value. In this embodiment, in order to detect the apparent magnetic permeability, the developing device is provided with an inductance head 48 , which is attached to one of the side walls of the developing device, as shown in FIG. 4 . [0036] The image forming apparatus is structured so that the results of the detection is inputted into an unshown E 2 ROM. More specifically, if it is detected that the apparent magnetic permeability of the developer is greater than the referential value, it means that the ratio of carrier particles in a specific volume of developer has become greater than the referential value; the developer has reduced in toner density. On the other hand, if the detection signal is smaller in value than the referential value, that is, if it is detected that the developer has reduced in the apparent magnetic permeability, it means that the developer has reduced in the ratio of carrier in the preset volume of developer; the developer has increased in toner density. The inductance detecting method is problematic in that even if the developer does not change in toner density, the sensor output is affected by the change in the apparent density of the developer itself, making it impossible to accurately control the developer in terms of toner density. In this embodiment, therefore, the toner density detected by the inductance detection method is compensated according to (1) changes having occurred to the developer due to its cumulative usage, (2) operational condition of the image forming apparatus, (3) ratio of the toner-covered area of the image being made, and (4) amount of the triboelectric charge of the toner (predicative control), to improve the accuracy with the magnetic permeability is detected. Not only is the inductance detection method inexpensive in terms of a sensor itself, but also, it is not affected by the spatial issues, and also, the problems related to the soiling attributable to the scattering of toner. Thus, it may be said that the inductance detection method is the most suitable toner density detecting method for an image forming apparatus which is low in cost and small in size. [5] Transferring Means [0037] In this embodiment, the primary transfer rollers 53 ( a - d ) are used as the transferring means. Each of the primary transfer rollers 53 ( a - d ) is kept pressed against the peripheral surface of the corresponding photosensitive drum 1 with the application of a predetermined amount of pressure, with the presence of an intermediary transfer belt 51 between the photosensitive drum and primary transfer roller 53 , forming a compression nip between and the peripheral surface of the photosensitive drum 1 and the intermediary transfer belt 51 . This compression nip serves as the transfer portion. To the transfer portion, the recording medium P (sheet of paper, transparent film, etc.) is delivered from a sheet feeding mechanism (unshown) with a preset control timing. [0038] As the recording medium P arrives at the transfer portion, it is conveyed between the photosensitive drum 1 and transfer roller 53 , which are being rotated, while remaining pinched between the two. While the recording medium P is conveyed through the transfer portion (nip), a positive transfer bias (+2 kV in this embodiment), which is opposite in polarity from the normal polarity to which the toner is charged, is applied to the transfer roller 51 from a transfer bias application power source (unshown). As a result, the toner images on the peripheral surfaces of the photosensitive drums 1 are electrostatically and sequentially transferred in layers onto the intermediary transfer belt 51 (image bearing member). The intermediary transfer belt 51 is suspended by multiple rollers by which it is stretched. It is made of an electrically conductive film, for example, polycarbonate film, polyethylene terephthalate resin film, polyfluorovinylidene resin film, etc., or a dielectric resin. The intermediary transfer belt 51 in this embodiment is formed of a dielectric polyimide. Regarding the delivery of the recording medium P, the recording medium P is picked out of the recording medium feeder cassette 8 by a pickup roller 81 , and is conveyed to a pair of registration rollers 82 . As the recording medium P reaches the pair of registration rollers 82 , the pair of registration rollers 82 temporarily halt the recording medium P by the leading end of the recording medium P to control the recording medium delivery timing so that the image(s) on the intermediary transfer belt 51 will be transferred onto the recording medium P across a preset area of the recording medium P. [0039] As the recording medium P and the four layers of monochromatic toner images, different in color, are conveyed through the nip between the secondary transfer roller 57 and intermediary transfer belt 51 , the four toner images are transferred together onto the recording medium P by the secondary transfer roller 57 . There is a cleaning apparatus 55 (cleaning means) for cleaning the intermediary transfer belt 51 , which is placed in contact with the intermediary transfer belt 51 to remove the transfer residual toner on the intermediary transfer belt 51 . The cleaned portion of the intermediary transfer belt 51 is used for the next cycle of image formation; the intermediary transfer belt 51 is repeatedly used for image formation. [6] Fixing Means [0040] After the transfer of the toner images onto the recording medium P by the secondary transfer roller 57 , the recording medium P is separated from the intermediary transfer belt 51 as if it is pealed away from the intermediary transfer belt 51 . Then, the recording medium P is conveyed to the fixing apparatus 7 , which is made up of a fixation roller 71 and a pressure roller 72 . Then the recording medium P is conveyed through the fixing apparatus 7 . As the recording medium P is conveyed through nip 72 formed by the fixation roller 71 and pressure roller 72 , the recording medium P and the toner images thereon are heated and pressed. As a result, the toner images are fixed to the surface of the recording medium P. Thereafter, the recording medium P is outputted as a print (copy). In order to facilitate the separation of the recording medium P from the fixation roller 71 , the fixing means 7 is provided with a mechanism for coating the surface of the fixation roller 71 with separation oil (for example, silicone oil). Thus, this oil adheres to (transfers onto) the recording medium P. After the fixation of the toner images to the recording medium P, the recording medium P is discharged into a delivery tray (unshown). When the image forming apparatus is in the mode for automatically forming an image on both surfaces of the recording medium P, the recording medium P is conveyed through the recording medium reversal path (unshown), and then, the above described image formation sequence is repeated to form an image on the back side of the recording medium. [Intermittent Microsecond Driving Mode] [0041] Next, an operation mode, which characterizes the present invention, will be described. This operational mode, hereafter, may be referred to as “intermittent microsecond driving mode”. When the image forming apparatus is operated in this mode, the length of time, and/or number times, the development sleeve is rotated, is varied according to the detected toner density ration T/D (ratio, in weight, of toner relative to developer). [0042] Referring to FIG. 5 which is a top plan view of the developing device driving portion, the shaft of the development sleeve 45 M is fitted with a gear 501 through which the mechanical force for driving the developing device is transmitted to the developing device. The developing device driving gear 501 is in mesh with a gear 502 , with which the apparatus main assembly is provided to drive the developing device (development sleeve 45 M). The gear 502 is solidly attached to the shaft of the developing device driving motor 503 . It transmits the driving force of the developing device driving motor 503 to the developing device (gear 501 ). The motor 503 is a stepping motor, which can quickly respond to an on- or off-signal. [0043] When the image forming apparatus is in the normal image formation mode, the developing device driving motor 503 is driven in the direction indicated by an arrow mark at a preset speed. However, it is designed so that it can be operated in the so-called intermittent microsecond driving mode when the image forming apparatus is not making an image. The intermittent microsecond driving mode, which characterizes the present invention, is such a mode that intermittently stops the rotation of the development sleeve 45 M two or more times while no image is formed. More specifically, the intermittent microsecond driving mode is such an operational mode that the speed at which the development sleeve 45 M is driven is switched two or more times between the first and second speeds. The second rotational speed may not be 0; the development sleeve 45 M does not need to be stopped. That is, the CPU controls the developing device driving motor 503 in such a manner that a sequence in which the development sleeve is increased in rotational speed and decreased is repeated two or more times with preset intervals. Here, the sequence in which the development sleeve is increased in rotational speed and decreased means the sequence which starts from when the development sleeve begins to be increased in rotational speed, and ends when the deceleration of the development sleeve ends. This sequence is repeated two or more times. The CPU controls the image forming apparatus so that each image forming portion is operated in this mode during the interval between two jobs. More concretely, referring to FIG. 6 , as soon as one image forming job ends (as soon as final developing operation of developing apparatus in given job ends), the developing means driving motor is rotated for 500 msec, in the same direction as the direction in which it is rotated for the normal image forming operation. Then, the motor is kept stationary for 500 msec. This combination of 500 msec of rotational period and 500 msec of stationary period makes up a single sequence. This sequence is continuously repeated two or more times. That is, in this embodiment, as soon as the last developing operation of the developing apparatus is ended in a given image forming job, the developing sleeve in each image forming portion is increased in rotational speed, and then, is decreased in rotational speed, twice or more times, while rotating the development sleeve in the same direction as it is rotated in an image forming operation. Intermittently driving the development sleeve for microseconds twice or more times can continuously vibrate the agglomerated toner particles, and therefore, it can efficiently disperse the agglomerated toner particles. Although the direction in which the development sleeve is driven in the intermittent microsecond driving mode in this embodiment is the same as the direction in which the development sleeve is driven during the normal image forming operation, it may be opposite from the normal direction. However, the structuring the developing apparatus (image forming apparatus) so that the direction in which the development sleeve is driven during the intermittent microsecond driving mode is the same as the normal direction is more efficiently disperse the agglomerated toner particles than the structuring the developing apparatus so that the direction in which the development sleeve is driven in the intermittent microsecond driving mode is opposite from the normal direction, because the former has an effect that the loose toner particles are made to collide with the toner particles having agglomerated on the back side of the blade, in addition to the aforementioned effect. [0044] Next, referring to FIG. 6 , the image formation sequence of the image forming apparatus in this embodiment is described. First, the rotation of the photosensitive drum is started. Immediately thereafter, the photosensitive drum is charged with the use of the charging means so that the surface potential of the photosensitive drum reaches a preset level. Then, a DC voltage is applied to the development sleeve, and roughly at the same time, the rotation of the development sleeve and the application of AC bias to the development sleeve are started, to develop the electrostatic latent image on the photosensitive drum into a toner image. After the completion of the formation of the toner image on the photosensitive drum, the AC voltage is turned off. Then, the development sleeve is intermittently rotated for 500 msec, with 500 msec intervals, to cause the lumps of toner, in which toner particles are about to agglomerate, to collapse, or to cause it to spit out the toner particles. The reason for keeping the AC voltage of the development bias turned off while the development sleeve is intermittently driven is for preventing toner from adhering to the drum. Further, the reason for keeping the DC voltage on is for preventing carrier adhesion. After the completion of the operation of the image forming apparatus in the intermittent microsecond driving mode, the DC bias for development is turned off, and then, the charge bias is turned off. Lastly, the rotation of the photosensitive drum is stopped to end the image forming operation. FIG. 10 is a block diagram of the intermittent microsecond driving mode in this embodiment. The CPU, which functions as the developing sleeve driving controlling means, operates the image forming apparatus in the intermittent microsecond driving mode, with a preset timing, to control the driving of the development sleeve by the developing means driving motor 503 . [0045] Table 1 shows the relationship among the number of times the development sleeve driving speed is switched in the intermittent microsecond driving mode, in which the image forming apparatus is operated for every preset number (which in this embodiment is 250) of continuously formed images (copies). In this embodiment, the number of times the development sleeve driving speed is switched in the intermittent microsecond driving mode is determined according to the toner density ratio (T/D). More concretely, as the toner density ratio (T/D) increases, either the number of times the development sleeve driving speed is switched in the intermittent microsecond driving mode, or the length of time the image forming apparatus is operated in the intermittent microsecond driving mode, is increased. [0046] The reason why the image forming apparatus is controlled as described above is as follows: The greater the toner density ratio T/D, the more likely is the toner to agglomerate, and therefore, more frequently is the image forming apparatus likely to output an image having abnormal white streaks. FIG. 2 is a graph showing the relationship between the cohesiveness of toner and the frequency with which lumps of toner particles appeared. The frequency with which the lumps of toner particles appeared was measured using the following method: a solid white image was formed on 300 sheets of A4 size, using four developers different in weight ratio of toner, which were 10%, 8%, 6%, and 4% (which is generally referred to as T/D ratio, and will be referred to as T/D ratio hereafter). Then, the first halftone image formed thereafter was evaluated; it was examined to determine whether the first halftone image had abnormal white streaks. As will be evident from FIG. 2 , the greater the TD ratio, the more likely is the toner to agglomerate, and therefore, the greater the frequency with which images having abnormal white streaks are outputted (formed). Further, the image forming apparatus in this embodiment is programmed so that as the average value of the T/D ratio becomes greater than a preset value (ratio) as shown in Table 1, the image forming apparatus is operated in the intermittent microsecond driving mode as soon as the ongoing image forming operation is completed, whereas while the average value of the T/D ratio remains below the preset value (ratio) during an image forming operation in which a substantial number of images are continuously formed, the image forming apparatus is not operated in the intermittent microsecond driving mode after the completion of the ongoing image forming operation. More specifically, the image forming apparatus in this embodiment is programmed so that if the average value of the T/D ratio is no less than 6%, the image forming apparatus is operated in the intermittent microsecond driving mode. [0000] TABLE 1 Number of sets of speed changes T/D Ratio = R (%) R < 4 4 ≦ R < 6 6 ≦ R < 8 8 ≦ R < 10 R ≧ 10 number of sets 0 0 3 6 9 [0047] Table 1 means the following: When the image forming apparatus is set to continuously form no less than 250 copies, the image forming apparatus is operated in the intermittent microsecond driving mode during the post-rotation operation carried out after the completion of the image forming operation. Incidentally, the post-rotation operation is to operate the photosensitive drum for a preset length of time to prepare the image forming apparatus for the next image forming operation after the completion of an image forming operation. More concretely, if the average value of the T/D ratio is no less than 6% and no more than 8% during an operation in which multiple copies are continuously made, the development sleeve is intermittently driven three times for 500 msec with 500 msec intervals, in the same direction as the normal direction. The number of times the sequence is repeated is set based on the average toner density T/D and Table 1 given above. As soon as the sequence is repeated the preset number times, the image forming apparatus is stopped (post-rotation is stopped), and at the same time, the indicator of the average toner density T/D is reset. That is, whether or not the image forming apparatus is to be operated in the intermittent microsecond driving mode after the completion of an image formation job is determined based on the average value of the toner density T/D during the image forming operation. Further, how many times the rotational speed of the development roller is to be switched while the image forming apparatus is operated in the intermittent microsecond driving mode, is determined based on the average value of the T/D ratio. Here, the “average value of T/D ratio” means the value obtained by dividing the sum of the values of the T/D ratio signals sampled between the beginning and end of an image formation job, by number of samples, or the value obtained by dividing the sum of the values of the T/D ratio signals sampled during the period from the beginning of an image forming job to the completion of 250th images (copies), by the number of times the T/D ratio is measured. [0048] In the case of an image forming operation in which no less than 250 images (copies) are continuously formed, changes which occurs to the toner density ratio T/D while 250 images (copies) are continuously formed is averaged. In this embodiment, the T/D ratio is detected for every specific number of images (copies) formed, and the detected T/D ratios are temporarily stored in an unshown ROM (storage means). Then, the value obtained by the CPU by averaging the stored values is used as the average T/D ratio. [0049] If this average value exceeds 6%, the image forming operation is temporarily stopped after the completion of the 250th image (copy), and then, the image forming apparatus is operated in the same manner as it is operated in the post-image formation operation. Then, the image forming apparatus is operated in the intermittent microsecond driving mode. On the other hand, if the detected toner density T/D ratio is no less than 6% and no more than 85, the image forming apparatus is operated in the intermittent microsecond driving mode for the length of time equivalent to three microsecond intermittent driving cycles, and then, the image forming operation in the intermittent microsecond driving mode is ended. Then, the abovementioned T/D ratio value storage is reset, and the interrupted image forming operation is restarted. Further, if the detected toner density ratio T/D is no less than 8%, but no more than 10% the image forming apparatus is operated in the intermittent microsecond driving mode for the length of time equivalent to six intermittent microsecond driving cycles. Further, if the average value of the toner density ratio T/D is no less than 8%, but no more than 10%, the image forming apparatus is operated in the intermittent microsecond driving mode for the length of time equivalent to nine intermittent microsecond driving cycles. Thereafter, the interrupted image forming operation is restarted. [0050] In a case where the average value of the detected toner density ratio T/D remains no more than 6%, the image forming apparatus is not operated in the intermittent microsecond driving mode for every 250th image (copy), that is, with an interval of 250 images (copies). However, regardless of the changes in the toner density ratio T/D, an ongoing image forming operation is interrupted once for every 2,500 images (copies), and then, is operated in the post-operation mode, to operate the image forming apparatus in the above described intermittent microsecond driving mode. FIG. 9 is the rough flowchart of this operation. As an image formation job is started (S 1 ), the formed images are counted by the CPU (S 2 ). As the image formation job continues, the T/D ratio in the developing device is detected with predetermined intervals (S 3 ), and the detected T/D ratios are stored in the ROM, while the detected TD ratios are averaged by the CPU (S 4 ) as the T/D ratio is detected. The CPU determines whether or not the image formation count is no more than the preset value (250 images (copies)) (S 5 ). [0051] If the image formation count obtained in Step S 5 is no more than the preset value (250), Step S 6 is taken, in which it is checked if the average T/D ratio up to this point is no less than a preset value (S 7 ). If it is no less than the preset value, the ongoing image formation job is interrupted to operate the image forming apparatus in the intermittent microsecond driving mode (S 8 ). Then, the image forming apparatus is operated in the intermittent microsecond driving mode for a length of time which corresponds to the average T/D ratio up to this point (S 9 ). Then, the average T/D ratio storage is reset, and the interrupted job is restarted (S 10 and S 11 ). If the image formation count is no more than the preset value (250) in Step S 5 , the CPU determines whether or not the last image (copy) in the current job has been completed (S 12 ). If it is determined by the CPU in Step S 12 that the image has not been formed on the last paper, Step S 5 is taken again, in which it is determined again whether or not the image count is no more than the preset value (250). If it is determined in Step S 12 that the image has been formed on the last paper prepared for the current job, the image forming apparatus is operated in the post-rotation mode (S 13 ), in which it is operated in the intermittent microsecond driving mode for the length of time which corresponds to the detected T/D ratio, and then, the image formation job is ended (S 14 -S 17 ). [0052] By operating the image forming apparatus as described above, the lumps of toner particles, which result from the agglomeration of toner particles and are likely to stagnate between the development sleeve and development blade, can be removed. It should be noted here that the above described conditions for operating the image forming apparatus in the intermittent microsecond driving mode are examples, and are not intended to limit the present invention in terms of the length of time the development sleeve is to be rotated in the normal direction, and the length of time the development sleeve is kept stationary, which is needless to say. Obviously, the abovementioned threshold values for the toner density ratio T/D are also not intended to limit the present invention in scope. [0053] Further, in this embodiment, the two speeds between which the rotational speed of the development sleeve is switched in the intermittent microsecond driving mode is the normal development sleeve speed for image formation and zero. However, all that is necessary is that when the image forming apparatus is in the intermittent microsecond driving mode, the rotational speed of the development sleeve is switched between two values. In other words, it is not unnecessary that one of the two speeds is zero. For example, the image forming apparatus in this embodiment is designed so that its process speed is 300 mm/sec, and also, that the development sleeve is rotated at the normal peripheral velocity of 450 mm/sec, which is 150% of the process speed, or a peripheral velocity of 225 mm/sec, which is half the normal process speed. Thus, the two speeds between which the rotation speed of the development sleeve is switch in the intermittent microsecond driving mode may be the 225 mm/sec and 450 mm/sec, and the effect obtained by using these two speeds will be similar to the above described effect. As will be evident from the above given description of the first preferred embodiment of the present invention, the image forming apparatus design in accordance with the present invention can prevent the problem that as an image forming apparatus is used to continuously form a substantial number of images (copies), images having abnormal white streaks may be outputted. Embodiment 2 [0054] The image forming apparatus in this embodiment is the same in basic structure as that in the first embodiment. Therefore, the general structure of the image forming apparatus in this embodiment will not be described. [0055] The characteristic feature of the image forming apparatus in this embodiment is that the frequency with which the image forming apparatus is operated in the intermittent microsecond driving mode (which was described regarding the first preferred embodiment of the present invention) is changed according to the extent of the developer deterioration in the developing device (according to amount of cumulative usage of developer in developing device). The reason for changing the frequency is that the more deteriorated is the toner in the developing device, the more likely is the toner to agglomerate, and therefore, the more frequently is the toner likely to agglomerate, making it more likely for the image forming apparatus to output unsatisfactory images as will be evident from FIG. 2 . [0056] One of the reasons why the longer is the toner used (the more deteriorated the toner), the more likely is the toner to agglomerate, is as follows: With the elapse of time, the additives (which hereafter will be referred to as external additives), which were adhered in advance to the surface of a toner particle to improve toner in fluidity, become separated from the toner particles and/or buried into the toner particles. Thus, the older toner is less in fluidity than the fresher toner. As for the examples of the external additive, there can be listed silicon carbide, silicon nitride, boron nitride, aluminum nitride, magnesium carbonate, organosilicon compound, in addition to such oxides as alumina, titanium oxide, silica, zirconium oxide, and magnesium oxide. [0057] FIG. 3 shows the changes in the extent of the toner agglomeration which occurred during an image forming operation in which 100,000 A4 size copies of an image which is 10% in image duty (each color) are continuously formed under the normal condition (23° C. and 50% RH) As will be evident from this graph, the toner in the developing device increased in cohesiveness roughly in proportion to the number of the formed copies. That is, when the body of toner, which is 40% in cohesiveness at the beginning of an image forming operation is continuously used for image formation, it increased in cohesiveness beyond 50% as the number of continuously made copies exceeded 100,000. As a body of toner exceeds 50% in cohesiveness, the toner particles in the body of toner are likely to agglomerate, and therefore, it is likely for lumps of toner particles to collect between the development sleeve and development blade. In this embodiment, therefore, the image forming apparatus is provided with a means for cumulatively counting the number of images (copies) formed by the apparatus, and the timing (frequency) with which the ongoing image formation job is interrupted to operate the image forming apparatus in the intermittent microsecond driving mode, is changed. That is, the number of times the image forming apparatus is operated in the intermittent microsecond driving mode per preset number of images (copies) formed is increased in proportion to the cumulative number of images (copies) formed. More concretely, if the cumulative number of images (copies) formed is no more than 10,000, the timing, with which the average toner density ratio T/D is obtained in order to determine whether or not the image forming apparatus is to be operated in the intermittent microsecond driving mode, is the same as that in the first embodiment. If the cumulative number of images (copies) formed is no less than 10,000, but no more than 50,000, the average toner density ratio T/D is obtained for every 200th image (copy). If the cumulative number of images (copies) formed is no less than 50,000, but no more than 100,000, the average toner density ratio T/D is obtained for every 150th images (copies). Further, if the cumulative number of images (copies) formed is no less than 100,000, the average toner density ratio T/D is obtained for every 100th images (copies). The number of times the rotational speed of the development sleeve is switched in the intermittent microsecond driving mode in this embodiment is the same as that given in Table 1. [0000] TABLE 2 Integrated Number of image formations number of image at which micro-driving formations (X) is executed   0 < X < 10000 250 10000 ≦ X < 50000 200 50000 ≦ X < 100000 150        X ≧ 100000 100 [0058] In the case of an image forming operation in which the number of the copies to be continuously made is no more than the referential value for switching from the actual image forming operation to the intermittent microsecond driving mode, the image forming operation is carried out as it is in the first preferred embodiment. That is, the image forming operation is not interrupted, and then, after the intended number of copies are formed, the image forming apparatus is operated in the intermittent microsecond driving mode according to Table 1. In this case, the image forming apparatus is operated in the intermittent microsecond driving mode for a length time which corresponds to the average value of the toner density ratios T/D detected before the intended number of copies were made, instead of being operated in the ordinary post-rotation mode, and then, the image forming apparatus is stopped. That is, it is based on the average value of the toner density ratio T/D obtained while the intended number of copies are continuously made that the CPU determines whether or not the image forming apparatus is to be operated in the intermittent microsecond driving mode. [0059] For example, if the cumulative number of images (copies) made is no more than 10,000, and the number of copies to be continuously made is no more than 250, the image forming apparatus is operated in the intermittent microsecond driving mode according to Table 1. That is, if the average value of the toner density ratio T/D is no less than 6%, but no more than 8%, the image forming apparatus is operated in the intermittent microsecond driving mode for a length of time equivalent to three intermittent microsecond driving cycles. [0060] By operating the image forming apparatus in the above described manner, it is possible to satisfactorily remove the lumps of toner particles resulting from the agglomeration of toner particles. [0061] In this embodiment, the extent of the usage of the developer in the developing device is determined based on the cumulative number of the images (copies) made with the use of the developer. However, it is not mandatory that the extent of the usage of the developer is determined based on the cumulative number of the images (copies) made with the use of the developer in the developing device. For example, the extent of the usage of the developer may be determined based on the cumulative length of time the development sleeve or stirring member of the developing device, or photosensitive member, is driven for image formation. That is, it may be determined that the longer the length of time the development sleeve or stirring member of the developing device, or photosensitive drum is driven for image formation, the greater the extent of usage of the developer in the developing device (more deteriorated is developer). Further, the extent of usage of the developer in the developing device may be determined based on the cumulative length of time the image forming apparatus was used for image formation, or cumulative number of image formation signals (video count). Embodiment 3 [0062] The image forming apparatus in this embodiment is the same in basic structure as that in the first embodiment. Therefore, the general structure of the image forming apparatus in this embodiment will not be described. [0063] The characteristic feature of the image forming apparatus in this embodiment is that, based on the cumulative number of images (copies) made by the image forming apparatus, the number of times the rotational speed of the development sleeve is switched while the image forming apparatus is operated in the intermittent microsecond driving mode, or the length of time the image forming apparatus is to be operated in the intermittent microsecond driving mode. That is, in this embodiment, the greater the cumulative number of the images (copies) made, the greater the number of times the rotational speed of the development sleeve is switched while the image forming apparatus is operated in the development sleeve intermittent microsecond driving mode, and also, the smaller the referential threshold value with which the toner density ratio T/D is compared to start operating the image forming apparatus in the developer sleeve intermittent microsecond driving mode. Given in Table 3 are the number of times the rotational speed of the development roller is to be switched while the image forming apparatus is operated in the intermittent microsecond driving mode. The reason for changing the number of times the rotational speed of the development sleeve is to be switched based on the cumulative number of images (copies) made is that the extent of toner deterioration is roughly proportional to the cumulative length of toner usage, and further, the more deteriorated is the toner, the more likely is the toner to agglomerate, as mentioned in the description of the first preferred embodiment. [0000] TABLE 3 T/D Ratio = R (%) 8 ≦ R < 4 4 ≦ R < 6 6 ≦ R < 8 R < 10 R ≧ 10 0 < X < 10000 0 0 3 6 9 10000 ≦ X < 50000 0 3 5 7 9 50000 ≦ X < 100000 0 4 6 8 10 X ≧ 100000 3 5 7 9 12 X = Number of image formations [0064] By operating the image forming apparatus in the above described manner, the lumps of toner particles, which result from the agglomeration of toner particles and are likely to stagnate between the development sleeve and development blade, can be more satisfactorily removed regardless of the cumulative length of developer usage (cumulative number of images (copies) made with developer in developing device). Further, the number of times an image forming operation has to be interrupted for the intermittent microsecond driving mode does not need to be significantly increased, and therefore, it is possible to prevent the problem that while an image forming apparatus is used for continuously making a significant number of copies, it gradually reduces in productivity. Embodiment 4 [0065] The image forming apparatus in this embodiment is the same in basic structure as that in the first embodiment, except that it can be operated in two or more processing speeds. Therefore, the general structure of the image forming apparatus in this embodiment will not be described. [0066] The characteristic feature of the image forming apparatus in this embodiment is that if the image forming apparatus is changed in processing speed, its development sleeve is also changed in rotational speed, and further, the image forming apparatus is changed in the frequency with which it is to be operated in the development sleeve intermittent microsecond driving mode. More concretely, if the development sleeve is reduced in rotational speed, the image forming apparatus is reduced in the frequency with which its image forming operation is interrupted for the intermittent microsecond driving mode. [0067] That is, how well a toner image becomes fixed to recording medium is affected by recording medium properties. Thus, the image forming apparatus in this embodiment is designed so that when a sheet of recording paper which is no less than 129 g/m 2 in basis weight is used as recording medium, the process speed is reduced to half the normal speed, and also, the rotational speed of the development sleeve is reduced to half the normal speed. As the speed of the development sleeve is reduced to half the normal speed, the amount by which developer is conveyed through the area between the development sleeve and development blade reduces, which in turn reduces the developer pressure in the area between the development sleeve and development blade, making it therefore less likely for the toner to agglomerate. Thus, when the image forming apparatus is operated at half the normal process speed, the referential (threshold) value, with which the cumulative number of images (copies) made, is compared in Step S 5 ( FIG. 9 ) in the first embodiment is doubled in this embodiment. [0068] By designing an image forming apparatus as described above, it is possible to prevent the problem that because an image forming apparatus is operated in the development sleeve intermittent microsecond driving mode more frequently than necessary, the image forming apparatus is unnecessarily reduced in productivity. [0069] As will be evident from the description of the preferred embodiments of the present invention given above, the present invention makes it possible to provide an image forming apparatus which uses two-component developer, more specifically, developer made up of magnetic carrier and nonmagnetic toner; simple in structure; and yet, does not output a defective image, the defects of which are attributable to the adhesion of lumps of toner particles resulting from the agglomeration of toner particles, to the regulating member for regulating in thickness the toner layer on the peripheral surface of the developer bearing member. [0070] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims. [0071] This application claims priority from Japanese Patent Application No. 141053/2008 filed May 29, 2008 which is hereby incorporated by reference.

An image forming apparatus includes an image bearing member for bearing an electrostatic latent image; a rotatable developer carrying member, provided opposed to the image bearing member, for carrying a developer including toner and a carrier to a position where the developer carrying member is opposed to the image bearing member; a regulating member for regulating the amount of the developer to be carried on the developer carrying member; a driving device for rotating the developer carrying member; a controller for controlling the driving device to execute, at the time of end of image formation, a plurality of continuous operations each including acceleration of a rotational speed of the developer carrying member and deceleration thereof following the acceleration.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 11/936,037, filed Nov. 6, 2007, which is hereby incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] Embodiments of the present invention relate generally to video processing and more specifically to a method and system for blending rendered images from multiple applications. [0004] 2. Description of the Related Art [0005] Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section. [0006] To enhance a user's viewing experience of computer-generated images, more and more computing devices are relying on a dedicated graphics subsystem with not one but multiple graphics processing units (“GPUs”) to perform rendering operations. The GPUs can be configured to perform operations such as split frame rendering (“SFR”) or alternate frame rendering (“AFR”) to scale up the number of pixels computed by the graphics subsystem. The GPUs can also be configured to efficiently perform anti-aliasing (“AA”) operations to improve image quality. Some of the conventional usage models involving multiple GPUs are shown in FIG. 1 . [0007] To illustrate, suppose there are two GPUs, GPU 0 and GPU 1 in the graphics subsystem. Under the usage model 1 , both the GPU 0 and GPU 1 are configured to carry out the rendering operations associated with the same application and scan out the rendered images to the only display device that is attached to the computing device and recognized by both the application and also the operating system executing on the computing device. The aforementioned SFR and AFR operations typically fall under this usage model 1 . Under the usage model 2 , each of GPU 0 and GPU 1 is attached to a distinct display device. Here, even though there are physically two GPUs and two display devices, the application and also the operating system executing on the computing device still only recognize one GPU and one display device. Each GPU is configured to compute one half of the surface that is being rendered and scan out the rendered images to its attached display device. The usage model 3 is similar to the usage model 1 , except one of the GPUs is designated to pull, blend, and scan out the blended results associated with the same frame and also the same application to the display device. The AA operation discussed above generally falls under this usage model 3 . [0008] As the foregoing illustrates, none of the usage models shown in FIG. 1 and described above permits the multiple GPUs to perform operations for different applications and still scan out the rendered images to a single display device. Thus, especially for a user with access to a single display device but with needs to maneuver multiple graphics-intensive operations, what is needed is a way to blend rendered images from multiple applications. SUMMARY OF THE INVENTION [0009] A method and system for blending rendered images from multiple applications are disclosed. One embodiment of the present invention sets forth a method, which includes the steps of generating a first rendered image associated with a first application, independently generating a second rendered image associated with a second application, applying a first set of blending weights to the first rendered image to establish a first weighted image, applying a second set of blending weights to the second rendered image to establish a second weighted image, and blending the first weighted image and the second weighted image before scanning out a blended result to a first display device. [0010] One advantage of the disclosed method and system is to enable high quality images from multiple applications to be displayed on a single display device cost effectively. BRIEF DESCRIPTION OF THE DRAWINGS [0011] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. [0012] FIG. 1 is a table illustrating some conventional usage models involving multiple GPUs; [0013] FIG. 2A is a flow chart illustrating the method steps of preparing for the blending of rendered images from multiple applications that are executing on a computing device in a picture on picture mode, according to one embodiment of the present invention; [0014] FIG. 2B illustrates an example of blending images from two different applications, according to one embodiment of the present invention; [0015] FIG. 3 is a block diagram of a computing device with a video bridge configured to implement one or more aspects of the present invention; [0016] FIG. 4A is a block diagram of another computing device also configured to implement one or more aspects of the present invention; and [0017] FIG. 4B illustrates a simplified process of blending rendered images from different applications without a specialized hardware unit, according to one embodiment of the present invention. DETAILED DESCRIPTION [0018] FIG. 2A is a flow chart illustrating the method steps of preparing for the blending of rendered images from multiple applications that are executing on a computing device in a picture on picture mode, according to one embodiment of the present invention. Suppose this computing device is a laptop computer coupled to a docking station. The laptop computer includes a primary GPU, GPU 0 , which resides in a first graphics adapter, and the docking station includes a secondary GPU, GPU 1 , which resides in a second graphics adapter. The first graphics adapter is further attached to a first display device. Once the computing device is configured to operate in the picture-on-picture mode, although only one display device is attached to the graphics adapters, in step 200 , the operating system executing on this computing device is informed that there are two GPUs, two graphics adapters, and two display devices attached to the graphics adapters. In one implementation, a driver associated with the graphics subsystem in the computing device intercepts the actual graphics resource information reported by the hardware components and provides the operating system with this specifically tailored graphics resource information. Even if the second graphics adapter is also attached to a second display device, one implementation of the driver still ensures that the GPU 1 transmits the rendered images to the GPU 0 to be scanned out to the first display device. [0019] According to one aspect of the present invention, the two GPUs are configured to generate graphics images with the same screen resolution. Thus, if the screen resolution supported by the primary GPU, such as the GPU 0 , is detected to have changed in step 202 , then one implementation of the driver imposes the newly changed screen resolution requirement on the secondary GPU, such as the GPU 1 , in step 204 . On the other hand, if the screen resolution supported by the primary GPU remains unchanged, then whether there is a request to modify the blending weights is checked in step 206 . Blending weights are primarily used to vary the visual effects of the images from different applications on the display device. Subsequent paragraphs will provide some examples illustrating the use of the blending weights. If the modification request is indeed detected in step 206 , then the blending weights are modified and stored in step 208 . In one implementation, the modified blending weights are stored in the registers of a video bridge. In addition, the various sets of blending weights can be associated with hotkeys. In particular, a hotkey can be a specific key or a combination of keys used in a specific sequence to represent a certain set of pre-determined blending weights. In other words, by switching from one hot key to another, the blending weights can be modified dynamically. In step 210 , the blending weights are applied to the rendered images generated by the GPUs, and these weighted images are blended. [0020] In conjunction with FIG. 2A and the discussions above, FIG. 2B illustrates an example of blending images from two different applications, according to one embodiment of the present invention. Suppose a first screen 220 includes a display window 222 showing images from an application A (e.g., a video conference session) and also the desktop of the display window 222 (e.g., the desktop of an operating system) supported by the GPU 0 , and a second screen 224 fully displays images from an application B (e.g., a game) supported by the GPU 1 . Suppose no weight is assigned to the desktop of the display window 222 ; weight A is assigned to the images from the application A, and weight B is assigned to the images from the application B. After the blending step of 210 , a resulting screen 226 is likely to show both the display window 222 with the images rendered by the GPU 0 and also the entire screen 224 with the images rendered by the GPU 1 . Due to the zero weight, the initial desktop of the screen 220 does not contribute to the resulting screen 226 . The same region on the screen 226 corresponding to the display window 222 in the screen 220 , on the other hand, includes the blended results of [(weight A * images from application A)+(weight B * images from application B)]/divider. Thus, if the images from application A are meant to display more prominently in the foreground, then the weight A is configured to be greater than the weight B . On the other hand, if the images from the application B should instead display more prominently in the foreground, then the weight B is configured to be greater than the weight A . Any numerical value assigned to the divider is used to further modify the effects of the different weights. [0021] Moreover, one way to modify these weights is through the use of hotkeys. In one implementation, a hotkey may be configured to showing the images from the application A only on the screen 226 (i.e., using this hot key results in setting the weight A to 1 and zeroing out all the other weights); another hotkey may be configured to showing the images from the application B only (i.e., using this hotkey results in setting the weight B to 1 and zeroing out all the other weights); and yet another hotkey may be configured to showing the images from both of the applications A and B (i.e., using this hotkey results in setting the weight A and weight B to non-zero values). [0022] In one implementation, the blending of the weighted images from multiple applications is performed by a specialized hardware component, such as a video bridge blending logic. FIG. 3 is a block diagram of a computing device with the video bridge configured to implement one or more aspects of the present invention. Without limitation, the computing device 300 may be a desktop computer, server, laptop computer, palm-sized computer, tablet computer, game console, cellular telephone, hand-held device, mobile device, computer based simulator, or the like. The computing device 300 may also include a docking system. The computing device 300 includes a host processor 308 , BIOS 310 , system memory 302 , and a chipset 312 that is directly coupled to a graphics subsystem 314 . BIOS 310 is a program stored in read only memory (“ROM”) or flash memory that is run at bootup. The graphics subsystem 314 includes a first and a second graphics adapters 315 and 317 , each with a single GPU, namely primary GPU 326 and secondary GPU 332 , respectively. If the computing device 300 is a laptop computer coupled to a docking system, then the primary GPU 326 resides in the laptop computer, and the secondary GPU 332 resides in the docking system. [0023] A graphics driver 304 , stored within the system memory 302 , configures the primary GPU 326 and the secondary GPU 332 to independently communicate with the two distinct applications that are executed by the host processor 308 . In one embodiment, the graphics driver 304 generates and places a stream of commands in a “push buffer,” which is then transmitted to the GPUs. When the commands are executed, certain tasks, which are defined by the commands, are carried out by the GPUs. [0024] In some embodiments of the computing device 300 , the chipset 312 provides interfaces to the host processor 308 , memory devices, storage devices, graphics devices, input/output (“I/O”) devices, media playback devices, network devices, and the like. Some examples of the interfaces include, without limitation, Advanced Technology Attachment (“ATA”) bus, Accelerated Graphics Port (“AGP”), Universal Serial Bus (“USB”), Peripheral Component Interface (“PCI”), and PCI-Express®. It should be apparent to a person skilled in the art to implement the chipset 312 in two or more discrete devices, each of which supporting a distinct set of interfaces. [0025] Connections 318 , 322 , and 324 support symmetric communication links, such as, without limitation, PCI-Express®. A “symmetric” communication link here refers to any two-way link with substantially identical or identical downstream and upstream data transmission speed. A connection 320 can be any technically feasible scalable bus that provides a direct connection between the primary GPU 326 and the secondary GPU 332 . One embodiment of the connection 320 can be implemented using the NVIDIA® SLI™ multi-GPU technology. The computing device 300 further includes a video bridge 316 , which not only provides an interface between the chipset 312 and each of the primary GPU 326 and the secondary GPU 332 via the connection 322 and the connection 324 , respectively, but the video bridge 316 also provides an interface between the primary GPU 326 and the secondary GPU 332 through the combination of the connections 322 and 324 and bypassing the chipset 312 . Moreover, the video bridge 316 includes the blending logic to apply the appropriate weights to the rendered images and blend the weighted images. [0026] As shown, the primary GPU 326 within the first graphics adapter 315 is responsible for outputting image data to a display device 338 . The display device 338 may include one or more display devices, such as, without limitation, a cathode ray tube (“CRT”), liquid crystal display (“LCD”), plasma display device, or the like. The primary GPU 326 is also coupled to video memory 328 , which may be used to store image data and program instructions. The secondary GPU 332 within the second graphics adapter 317 is also coupled to video memory 334 , which may also be used to store image data and program instructions. The primary GPU 326 does not have to be functionally identical to the secondary GPU 332 . In addition, the sizes of the video memories 328 and 334 and how they are utilized by the first and second graphics adapters 315 and 317 , respectively, do not have to be identical. [0027] To illustrate the aforementioned blending operation in the computing device 300 , suppose the primary GPU 326 performs rendering operations for an application A, and the secondary GPU 332 performs rendering operations for an application B. When the secondary GPU 332 renders a frame, it pushes the rendered image associated with the application B from a secondary frame buffer in video memory 334 to the video bridge 316 . Similarly, the primary GPU 326 also pushes the rendered image associated with the application A from a primary frame buffer in video memory 328 to the video bridge 316 . The blending logic in the video bridge 316 then retrieves the blending weights stored in the registers of the video bridge 316 , applies the appropriate blending weights to both of these rendered images, and blends the weighted images. In one implementation, the blended results are stored in the video memory 328 for the primary GPU 326 to scan out to the display device 338 . It should be noted that the graphics subsystem 314 in this implementation neither depends on the resources of the chipset 312 nor the GPUs to carry out the blending operation. [0028] According to an alternative embodiment of the present invention, a computing device 400 as shown in FIG. 4A with multiple GPUs but without a video bridge and the hardware blending logic can still be configured to perform the aforementioned blending operation. Specifically, FIG. 4B illustrates a simplified process of blending rendered images from different applications without a specialized hardware unit, according to one embodiment of the present invention. Using the computing device 400 to illustrate such a process, the primary GPU 426 and the secondary GPU 432 perform the rendering operations associated with two different applications independently in steps 450 and 452 , respectively. In one implementation, the computing device 400 allocates a block of memory from system memory 402 for use as a temporary buffer 406 . When a secondary GPU 432 renders a frame associated with the application B, the application B requests to flip this rendered frame by transmitting it to the temporary buffer 406 in step 454 . After the primary GPU 426 renders the frame associated with the application A, it then pulls the rendered image from the temporary buffer 406 , applies the appropriate blending weights to the two rendered images, and blends the two weighted images in step 456 . Here, the primary GPU 426 treats the rendered frame from the secondary GPU 432 as texture. In one implementation, the primary GPU 426 stores the blended results in a primary frame buffer in video memory 428 to be scanned out to a display device 438 . It should be noted that the resources of the chipset 412 and also the primary GPU 426 in this implementation are utilized to carry out the blending operation. [0029] In yet another alternative implementation, instead of pushing the rendered image to the system memory 402 , the secondary GPU 432 can push the rendered image to the primary frame buffer in the video memory 428 through connections 422 , 424 , and chipset 412 or through connection 420 directly in step 454 . Similar to the computing device 300 described above, the connections 422 and 424 support symmetric communication links, such as, without limitation, PCI-Express®, and the connection 420 can be any technically feasible scalable bus that provides a direct connection between the primary GPU 426 and the secondary GPU 432 . [0030] It is worth noting that in one implementation, the primary GPU 426 and the secondary GPU 432 are synchronized before proceeding to step 456 . It should be apparent to a person with ordinary skills in the art to apply any synchronization scheme (e.g., semaphores) without exceeding the scope of the present invention. Furthermore, although the graphics subsystems 314 and 414 of systems 300 and 400 , respectively, are shown to provide certain graphics processing capabilities, alternative embodiments of these graphics subsystems may process additional types of data, such as audio data, multimedia data, or the like. [0031] The above description illustrates various embodiments of the present invention along with examples of how aspects of the present invention may be implemented. The above examples, embodiments, and drawings should not be deemed to be the only embodiments, and are presented to illustrate the flexibility and advantages of the present invention as defined by the following claims.

One embodiment of the present invention sets forth a method, which includes the steps of generating a first rendered image associated with a first application, independently generating a second rendered image associated with a second application, applying a first set of blending weights to the first rendered image to establish a first weighted image, applying a second set of blending weights to the second rendered image to establish a second weighted image, and blending the first weighted image and the second weighted image before scanning out a blended result to a first display device.

FIELD OF THE INVENTION [0001] The present invention relates to dental and orthopedic prostheses and methods for producing improvements in dental and orthopedic prostheses using functionally graded materials (“FGMs”) such as a functionally graded glass/zirconia/glass (G/Z/G) sandwich material. BACKGROUND OF THE INVENTION [0002] Teeth play a critically important role in our lives. Loss of function reduces the ability to eat a balanced diet which results in negative consequences for systemic health. Loss of aesthetics can negatively impact social function. Both function and aesthetics can be restored with dental crowns and bridges. Ceramics are attractive dental restoration materials because of their aesthetics, inertness, and biocompatibility. However, ceramics are brittle and subject to premature failure, especially after repeated contact including slide-liftoff masticatory loading in a moist environment (Kim et al. (2007) Journal of Dental Research 86(11): 1046-1050; Lawn et al. (2001) The Journal of Prosthetic Dentistry 86(5): 495-510; Lawn et al. (2001) J Prosthet Dent 86(5): 495-510; Zhang et al. (in press) “Fatigue Damage in Ceramic Coatings from Cyclic Contact Loading with Tangential Component.” Journal of the American Ceramic Society ) Fracture rates of ceramic restorations may seem low at 3-4% per year (Fradeani et al. (1997) Int. J. Prothodont. 10: 241-7; Malament et al. (1999) J. Prosthet. Dent. 81: 23-32; Sjogren et al. (1999) Int. J. Prosthodont. 12: 122-8; Sailer et al. (2006) Quintessence International 37(9): 685-693; Sailer et al. (2007) Clin. Oral Impl. Res. 18(3): 86-96; Pjetursson et al. (2007) Clin. Oral Impl. Res. 18(3): 73-85). However, failure can cause significant patient discomfort and loss of productive lifestyle. The vulnerability of dental ceramic restorations is exacerbated by damage, fatigue loading, and moisture. [0003] According to a survey conducted by American Dental Association, more than 45 million new dental crowns, of which over 37 million were porcelain (ceramic) based, were provided by dentists in 1999 (ADA (2002). “The 1999 Survey of Dental Services Rendered.”). As the population ages, the number will increase. Despite continuous efforts to improve the strength of dental ceramics, all-ceramic dental crowns continue to fail at a rate of approximately 3-4% each year (Burke et al. (2002) J Adhes Dent 4(1): 7-22). The highest fracture rates are on posterior crowns and bridges where stresses are greatest. Dental crowns generate over $2 billion each year in revenues with 20% of the units being all-ceramic (Nobel Biocare 2004). Dental ceramics that best mimic the optical properties of enamel and dentin are predominantly glassy materials principally feldspar (a group of minerals having main constituents of silica and alumina) (Kelly (1997) Annual Reviews of Materials Science 27: 443-68; Kelly (2004) Dent. Clin. N. Am. 48: 513-30). The original dental porcelain contained high feldspathic glass content and was extremely brittle and weak (S (strength) approximately ˜60 PMa) (McLean, J. W. (1979) The Science and Art of Dental Ceramics . Chicago, Quintessence Publishing Co. Inc.; Binns, D. (1983) The Chemical and Physical Properties of Dental Porcelain . Chicago, Quintessence Publishing Co. Inc.). Therefore, despite the aesthetic advantage, the early porcelain crowns were not widely used in dentistry (Van, N. R. (2002). “An Introduction to Dental Materials.” 231-46). [0004] Dental ceramics have become increasingly popular as restorative materials due to improvements in strength. Several methods have been developed to improve the strength of dental ceramics including adding uniformly disperse appropriate filler particles throughout a glass matrix, referred to as “dispersion strengthening” (McLean et al. (1965) Br. Dent. J. 119: 251-67). The first fillers used in dental ceramics were leucite particles (Denry (1996) Crit. Rev. Oral. Biol. Med. 7: 134-43). Commercial dental ceramics containing leucite as a dispersion strengthening fillers include IPS Empress (S˜120 PMa) (Ivoclar-Vivadent, Schaan, Liechtenstein) and Finesse All-ceramic (S approximately 125 MPa) (Dentsply Prosthetics, York, Pa.). Particle strengthening can also be achieved by heat-treating the glass to facilitate the precipitation and subsequent growth of crystallites within the glass, termed “ceraming”. Dental ceramics produced using the ceraming process are called glass-ceramics. Several commercial products such as Dicor (S˜160 MPa) (Dentsply), IPS Empress II (S˜350 MPa) (Ivoclar-Vivadent) and, more recently, IPS e.max Press (S˜525 MPa) (Ivoclar-Vivadent) are examples. The leucite-strengthened porcelains and the glass-ceramics are translucent, so single layer (monolithic) crowns can be made from these materials. However, only moderate strength increases can be achieved via the particle strengthening techniques. Therefore, monolithic ceramic crowns experience high failure rates range from 4-6% for Dicor molar crowns (Malament et al. (1999) J. Prosthet. Dent. 81: 23-32) and 3-4% per year for IPS Empress crowns (Fradeani et al. (1997) Int. J. Prothodont. 10: 241-7; Sjogren et al. (1999). Int. J. Prosthodont. 12: 122-8). Note: comprehensive clinical reports on the new IPS e.max Press crowns are not available at this stage. [0005] The current approach to the fracture problem of monolithic crowns is a layer-structure with aesthetic but weak porcelain veneers fused onto strong but opaque ceramic cores. This involves an increase in crystalline content (from approximately 40 vol % to 99.9 vol %) accompanied by a reduction in glass content. The first successful strengthened core ceramic was made of feldspathic glass filled with approximately 40 vol % alumina particles (McLean et al. (1965). Br. Dent. J. 119: 251-67). The alumina fillers increased the flexural strength of the ceramic to approximately 120 MPa with a trade off in translucency; hence veneering was required. Using McLean's approach, in 1983 Coors Biomedical (Golden, Colo.) developed Cerestore all-ceramic crowns with a ceramic core containing ˜60 vol % of alumina (Sozio et al. (1983). J. Prosthet. Dent. 69: 1982-5). However, following problems with fractured crowns the manufacturer withdrew the system. A similar product from the same era, the Hi-Ceram crown (Vita, Bad Säckingen, Germany) with its core material containing about the same amount of alumina as the Cerestore core, also failed to meet the satisfactory for posterior restorations (Bieniek et al. (1994). Schweitz Monatsschr Zahnmed 104: 284-9). The Hi-Ceram crown was replaced by In-ceram crown (Vita) in 1990. The In-ceram crown had a core that was fabricated by lightly sintering an alumina powder compact and then infiltrating the still porous alumina matrix with a low viscosity glass. The final core material contained approximately 70 vol % of alumina and had a flexural strength of approximately 450 MPa (Probster (1992) Int J Prosthodont 5(5): 409-14). In 1993, Procera (Nobel Biocare, Göteborg, Sweden) presented the all-ceramic crown concept (Anderson et al. (1993). Acta Odontol Scand 51: 59-64), where the fully dense core material contained 99.9 vol % alumina and displayed a flexural strength of 675 MPa. Several years later, even stronger Y-TZP ceramic was introduced to dentistry as a core material with a flexural strength over 1200 MPa. [0006] Although documentation regarding the clinical performance of the zirconia core backed crowns is still limited, laboratory in vitro tests (B. Kim et al, (2007) Journal of Dental Research, 86(2): 142-146) and anecdotal clinical reports (Donovan (2005) Journal of Esthetic and Restorative Dentistry 17(3): 141-3) indicate that the zirconia cores are very fracture resistant. However, a frequent problem is fracture of the porcelain veneer. Despite significant improvements in the performance of existing dental ceramics, the structural stability of all-ceramic systems remains less reliable than metal-ceramic systems (porcelain veneers fused onto metal copings) (Kelly (2004) Dent. Clin. N. Am. 48: 513-30). While efforts in improving the structural performance of all-ceramic crowns have been focused on making monolithic materials stronger or fabricating stronger cores to support weak, but aesthetic porcelain veneers, few innovative approaches have emerged to develop more damage resistant and longer lasting ceramic crowns. This is due in part to the lack of current knowledge of damage modes that could occur in a ceramic crown under mastication. [0007] Unfortunately, no current materials, including monolithic ceramics stronger (orthopedic and dental prostheses) or strong cores to support weak, but aesthetic porcelain veneers (dental prostheses) can effectively suppress both contact and flexural damages. In addition, veneered strong ceramic dental prostheses have a dense, high purity crystalline structure at the cementation internal surface that cannot be readily adhesively bonded to tooth dentin as support. Surface roughening treatment such as particle abrasion is commonly used to enhance the ceramic-luting agent bond. However, particle abrasion also introduces surface flaws or microcracks that can cause deterioration in the long-term flexural strength of ceramic prostheses. (Zhang et al. (2004) Journal of Biomedical materials research 71B(2): 381-6; Zhang et al. (2005) Journal of Biomedical materials research 72B: 388-92; Zhang et al. (2006) The International Journal of Prosthodontics 19(5): 442-8). [0008] Recent advances in theoretical and experimental work have shown that functionally graded materials, referred to as FGMs, may provide unprecedented resistance to contact damage (Suresh et al. (2003) U.S. Pat. No. 6,641,893; Suresh et al. (1997) Acta Materialia 45(4): 1307-21; Jitcharoen et al. (1998) Journal of the American Ceramic Society 81(9): 2301-8; Suresh et al. (1999) Acta Materialia 47(14): 3915-3926). Such damage resistance cannot be realized with conventional homogeneous materials. FGMs are made of two materials that are combined so that the surface of the FGM is composed entirely of material A, and the interior is composed entirely of material B. Additionally, there is a continuous change in the relative proportions of the two materials from the surface to interior. One known FGM is a thick ceramic block, alumina or silicon nitride, infiltrated with a low elastic modulus aluminosilicate glass or oxynitride glass (SiAlYON), respectively, on one surface to produce a graded glass/ceramic (G/C) structure that suppresses contact damage at the top, occlusal surface (Jitcharoen et al. (1998) Journal of the American Ceramic Society 81(9): 2301-8). However, upon infiltration of dense ceramics, the glass penetrates the grain boundaries and grain boundary triple junctions, and as a result, the ceramic grains gradually separate. This leads to an increase in volume at the surface of graded structure and is accompanied by warpage or bending of the specimens where the glass-impregnated surface is convex. [0009] Zirconium dioxide (ZrO 2 ), sometimes known as zirconia, is a white crystalline oxide of zirconium. Its most naturally occurring form, with a monoclinic crystalline structure, is the rare mineral, baddeleyite. Pure ZrO 2 has a monoclinic crystal structure at room temperature and transitions to tetragonal and cubic at increasing temperatures. The volume expansion caused by the cubic to tetragonal to monoclinic transformation induces very large stresses, and will cause pure ZrO 2 to crack upon cooling from high temperatures. Several different oxides are added to zirconia to stabilize the tetragonal and/or cubic phases: magnesium oxide (MgO), yttrium oxide, (Y 2 O 3 ), calcium oxide (CaO), and cerium oxide (Ce 2 O 3 ), amongst others. [0010] If sufficient quantities of the metastable tetragonal phase zirconia is present, then an applied stress, magnified by the stress concentration at a crack tip, can cause the tetragonal phase to convert to monoclinic, with the associated volume expansion. This phase transformation can then put the crack into compression, retarding its growth, and enhancing the fracture toughness. This mechanism is known as transformation toughening, and significantly extends the reliability and lifetime of products made with partially stabilized zirconia. A special case of zirconia is that of tetragonal zirconia polycrystalline or TZP, which is indicative of polycrystalline zirconia composed of only the metastable tetragonal phase. This material is also used in the manufacture of frameworks for the construction of dental restorations such as crowns and bridges which are then veneered with a dental feldspathic porcelain, as well as femoral heads for the total hip replacement. SUMMARY OF INVENTION [0011] The present invention takes advantage of the discovery that fracture problems of ceramic prostheses are minimized by a new generation of damage resistant ceramic prostheses utilizing functionally graded materials (FGMs). The present invention represents an improvement over the G/C structure of the prior art to a graded G/C/G structure by infiltrating top and bottom ceramic surfaces with glass. The present invention features a structure of G/C/G comprising an outer surface aesthetic residual glass layer, a graded glass-ceramic layer, and a dense interior ceramic. [0012] In a first aspect, the present invention provides a method for preparing a functionally graded glass/ceramic/glass (G/C/G), preferably a functionally graded glass/zirconia/glass (G/Z/G) sandwich material, comprising: (a) applying a powdered glass-ceramic composition to accessible surfaces of a presintered zirconia substrate thereby covering the zirconia substrate surfaces with a layer of the composition wherein the coefficient of thermal expansion (CTE) of the glass-ceramic and the coefficient of thermal expansion (CTE) of the substrate material are substantially the same; and (b) infiltrating the glass-ceramic composition into the substrate and densifying the substrate by heating the substrate. In some embodiments, the heating is performed to approximately the sintering temperature of the substrate. [0013] In some embodiments, the substrate comprises yttria-tetragonal zirconia polycrystal (Y-TZP). In other embodiments, the substrate is presintered at a temperature of from about 900° C. to about 1400° C. In yet other embodiments, the densifying is performed in one or more firing cycles at a temperature of from about 1200° C. to 1550° C., or 1300° C. to 1500° C., preferably from about 1400° C. to 1450° C. Also, in some embodiments, the powdered glass-ceramic composition is dispersed in an aqueous based solution. It is preferred that the powdered glass-ceramic composition comprises one or more oxides selected from the group consisting of SiO 2 , Al 2 O 3 , K 2 O, Na 2 O, BaO, Tb 4 O 7 , and CaO. Each of the one or more oxides may be present in a weight percent of about 1%, 2%, 5%, 10%, 15%, 20%, 25%, 30%, or even 50%. In some embodiments only of the oxides is present, while in other embodiments, two, three, four, five, six, seven or even eight of the oxides may be present. Also, in particularly preferred embodiments, the CTE of the glass and the CTE of the zirconia are substantially the same. That is, when the CTEs are substantially the same, in some embodiments, the CTE of the glass and the CTE of the zirconia are within about 50%, 40%, 30%, 25%, 20%, 10%, 5%, 2%, 1% or even 0.5% or 0.25% of each other. In especially preferred embodiment, the CTE of the glass is approximately about 10.0 to 11.0, or 10.3 in/in/° C., from 0 to 430° C., and the CTE of the zirconia is approximately about 10.0 to 11.0, or 10.3 in/in/° C., from 0 to 430° C. In some embodiments, the presintered zirconia substrate is presintered by a microwave technique, and in some embodiments, the glass/zirconia/glass (G/Z/G) sandwich material is densified by a microwave technique. [0014] In a second aspect, the present invention provides a functionally graded glass/ceramic/glass composite structure comprising an outer residual glass layer, an underlying graded glass-ceramic layer, and a dense interior ceramic. In some embodiments, the functionally graded glass/ceramic/glass composite structure is substantially non-susceptible to warppage or bending. The functionally graded glass/zirconia/glass (G/Z/G) sandwich material may be produced in some instances by the method described above as a first aspect of the invention. [0015] In some embodiments, the functionally graded glass/ceramic/glass composite structure is composed of an underlying ceramic made substantially of yttria-tetragonal zirconia polycrystal (Y-TZP). In some embodiments, the CTE of the glass and the CTE of the zirconia are substantially the same. That is, when the CTEs are substantially the same, in some embodiments, the CTE of the glass and the CTE of the zirconia are within about 50%, 40%, 30%, 25%, 20%, 10%, 5%, 2%, 1% or even 0.5% or 0.25% of each other. In especially preferred embodiment, the CTE of the glass is approximately about 8.0 to 15.0, 10.0 to 11.0, or 10.3 in/in/° C., from 0 to 430° C., and the CTE of the zirconia is approximately about 8.0 to 15.0, 10.0 to 11.0, or 10.3 in/in/° C., from 0 to 430° C. [0016] In some embodiments, the outer glass layer may be from 5 to 1,000 microns thick, sometimes 10 to 750 microns thick, or 20 to 500 microns thick, or 25 to 250 microns thick, or 30 to 100 microns thick, for instance. Likewise, in some embodiments, the graded glass-ceramic layer may be from 10 to 500 microns thick, or 20 to 300 microns thick, or 30 to 200 microns thick, or 40 to 150 microns thick, or 50 to 125 microns thick, or 60 to 100 microns thick, for instance. [0017] In a third aspect, the present invention provides a prosthesis comprising a functionally graded glass-ceramic/ceramic/glass-ceramic composite structure or a graded glass-ceramic/ceramic structure. The prosthesis may be, for instance, an aesthetic and damage-resistant ceramic orthopedic prosthesis, orthopedic stems, orthopedic/dental anchors, orthopedic/dental implants, dental prostheses, and endodontic posts. The structure may comprise an outer residual low modulus glass layer, an underlying graded glass-ceramic layer, and a dense interior ceramic. BRIEF DESCRIPTION OF DRAWINGS [0018] FIG. 1 is a schematic diagram illustrating a preferred processing method for the fabrication of a flat G/Z/G composite. [0019] FIG. 2 provides optical microscope images showing cross-sectional views of polished G/Z/G FGMs (d=1.5 mm) fabricated from Y-TZP plates presintered at (a) 1400° C. for 1 hour and (b) 1100° C. for 1 hour. Glass infiltration and densification were carried out at 1450° C. for 2 hours in air. Different thicknesses of surface graded glass-ceramic layers in the two cases. Inserts in FIG. 2 b are SEM images showing surface graded layer containing high glass content whereas the interior consists of dense Y-TZP. (c) A low magnification SEM image of G/Z/G fabricated from 1100° C. for 1 hour presintered specimen revealing (from left to right): an outer surface residual glass layer (approximately 6 μm thick) and a graded glass-zirconia layer. The glass content (black) gradually decreases as proceeding towards the interior. [0020] FIG. 3 shows XRD spectra of (a) homogenous Y-TZP sintered at 1450° C. for 2 hours; (b) Y-TZP presintered at 1100° C. for 1 hour; and (c) G/Z/G frabricated from infiltration and densification of presintered (1100° C. for 1 hour) at 1450° C. for 2 hours. T: tetragonal zirconia phase, and G: amorphous glass phase. No secondary crystalline phase exists in G/Z/G FGMs. Spectra acquired using CuKα radiation with a scan rate of 1°/min and a step size of 0.2°. [0021] FIG. 4 is a bar chart depicting critical loads for internal surface radial cracking of ceramic plates (d=1.5 or 0.4 mm) on polycarbonate substrates. Ceramic plates are G/Z/G fabricated from glass infiltration of 1400° C. presintered Y-TZP and the bulk Y-TZP. Note the advantage of G/Z/G over Y-TZP is more pronounced for thinner samples. [0022] FIG. 5 is a digital photograph depicting (a) a G/Z/G plate (1.5 mm thick) fabricated from glass infiltration of 1400° C. presintered Y-TZP using a glass-ceramic composition 1. For comparison, a monolithic glass ceramic (b) Empress II, porcelain veneered zirconias (c) Lava and (d) Cercon of 1.5 mm thickness are also shown. Also, a one cent coin is shown (e) for size reference. [0023] FIG. 6 is a schematic diagram illustrating a ceramic liner and a ceramic femoral head with (a) and (b) both surfaces graded or (c) and (d) only one surface graded for an orthopedic prosthesis. (e) Ceramic dental prosthesis (for both monolithic or core structures) with graded structures at surfaces subject to wear, contact, and impact. [0024] FIG. 7 is a schematic illustration of crack geometry for cyclic loading of (a) monolith ceramic coatings and (b) veneered ceramic layers on compliant substrates with sphere of radius r at load P in water. Near-contact surface damage modes: outer cone (O); inner cone (I); median crack (M). Far-field internal surface radial crack (R). DETAILED DESCRIPTION OF THE INVENTION [0025] An FGM structure where a thick ceramic block, alumina or silicon nitride, is infiltrated with a low elastic modulus aluminosilicate glass or oxynitride glass, respectively, on one surface to produce a graded glass/ceramic (G/C) structure that suppresses contact damage at the top, occlusal surface is known in the art. (Jitcharoen et al. (1998) Journal of the American Ceramic Society 81(9): 2301-8) The present invention provides a graded G/C/G structure by infiltrating top and bottom ceramic surfaces with glass. The G/C/G structure suppresses both occlusal surface contact damage and cementation internal surface flexural damage. In addition, the unique structure of G/C/G, an outer surface aesthetic residual glass layer, a graded glass-ceramic layer, and a dense interior ceramic ( FIG. 2 ), allows optimizing optical and cementation properties. [0026] The FGM structure of the present invention having a low modulus glass ceramic at both the top and the bottom surfaces, sandwiching a high modulus, strong ceramic interior, improves resistance to both contact and flexural damage. In addition, the FGM structure of the present invention together with outer surface residual glass layers may be used to enhance the aesthetics and cementation behavior of polycrystalline dental ceramic cores, including the exceptionally strong class of zirconia ceramics. Moreover, it is possible to optimize the thickness of the surface graded layer and residual glass layer thereby providing the best combination of aesthetics, resistance to contact damage and flexural fracture for G/C/G FGMs. [0027] Glass-ceramic powders are taught in U.S. Provisional Patent Application Ser. No. 60/860,165, the disclosure of which is herein incorporated by reference in its entirety. The present invention provides G/Z/G structures having a thickness useful for dental applications. In many embodiments, the glass-ceramic powders used for infiltrating G/Z/G contain one or more of, but are not restricted to, the following main oxides (i.e. at 1.0 weight percent or more): SiO 2 , Al 2 O 3 , K 2 O, Na 2 O, BaO, Tb 4 O 7 , and CaO. The composition of the infiltrating glass-ceramic can vary, as long as its CTE is similar or preferably approximately the same as that of the Y-TZP in a temperature range between the glass-ceramic transition temperature (T g ) and room temperature and the final product has an aesthetic appearance. Silica based glass has a poor permeability in dense Y-TZP even at approximately 1450° C., which is similar to the sintering temperature of this material. In addition, post-sintering glass infiltration at this temperature may result in grain growth and/or destabilizing of the tetragonal phase, which are known to be deleterious for hydrothermal stability of Y-TZP in the body (Chevalier, et al. (2004) Biomaterials 25: 5539-45; Chevalier (2006) Biomaterials 27: 534-43). Therefore, it is preferred to infiltrate the presintered Y-TZP and to combine infiltration and densification in one process. By doing so, the thickness of the graded glass-ceramic layer may be controlled by the porosity of presintered bodies. Further, combining infiltration and densification in one process can avoid grain growth and destabilizing of the tetragonal phase. [0028] The G/C/G system of the present invention suppresses both occlusal surface contact damage and cementation internal surface flexural damage. The G/C/G system of the present invention substantially overcomes the warpage or bending problems associated with the G/C systems of the prior art. The unique structure of the present invention G/C/G, which provides an outer surface aesthetic residual glass layer, a graded glass-ceramic layer, and a dense interior ceramic provides the advantage that optical and the cementation properties may be optimized. FGMs with low modulus glass ceramics at both top and bottom surfaces, sandwiching a high modulus, strong ceramic interior, improve the resistance to both contact and flexural damage. Such graded structures together with the outer surface residual glass layers may be utilized to enhance the aesthetics and cementation behavior of polycrystalline dental ceramic cores. [0029] In a copending provisional application, U.S. Provisional Patent Application Ser. No. 60/860,165, the disclosure of which is herein incorporated by reference, G/C/G structures are disclosed based upon a sandwiched layer of alumina. The present invention is based in part upon the unexpected discovery that FGMs having surprisingly superior properties are produced when the sandwiched layer comprises the exceptionally strong class of zirconia ceramics. It has been shown that continuously graded G/C composites, without significant internal stresses, may be produced by infiltrating glass into a dense ceramic surface where the two constituents G and C possess similar coefficients of thermal expansion (CTEs) and Poisson's ratio. Zirconia, more specifically yttria-tetragonal zirconia polycrystal (Y-TZP), is far superior to alumina in terms of mechanical properties, and the G/Z/G system used in the present invention provides robust, aesthetic, thin all-ceramic prostheses for less invasive posterior applications. However, the permeability of silica based glass in dense Y-TZP is poor even at temperatures near its sintering temperature. In addition, post-sintering glass infiltration at temperatures near the sintering temperature results in grain growth and/or destabilization of the tetragonal phase, which in turn deteriorates the hydrothermal stability of Y-TZP (Chevalier, et al. (2004) Biomaterials 25: 5539-45). [0030] The present invention provides a G/Z/G FGM produced by infiltrating the surfaces of presintered Y-TZP with a powdered glass-ceramic slurry which has a similar CTE and Poisson's ratio to those of Y-TZP, and by combining infiltration and densification in one stage. By the term “presintered” is meant that the powdered composition of the substrate has been subjected to an elevated temperature/time heating schedule, but yet below that which would effect full densification of the compound. In this manner, complications arising from the post-sintering infiltration/heat-treatment can be avoided and the various graded layer thicknesses can be produced by controlling the porosity of presintered bodies using different presintering temperatures. Further, the aesthetics of FGMs is governed by the thickness of the surface residual glasses and the microstructure of graded layers. Therefore, an optimal thickness of the graded layer and surface residual glass layer that results in the best combination of aesthetics, resistance to contact damage and flexural fatigue is provided. The new G/Z/G composites offer better resistance to flexure-induced damage, better aesthetics, better veneering and cementation properties, and better resistance to hydrothermal degradation over the existing commercial Y-TZP cores. [0031] The appearance of G/Z/G infiltrated on partially dense bodies presintered at 1400° C. is shown in FIG. 6 , along with commercial monolithic glass ceramic Empress II (1.5 mm thick), veneered Lava zirconia (1 mm porcelain and 0.5 mm zirconia) and Cercon zirconia (1 mm porcelain and 0.5 mm zirconia). For better aesthetics, a thin veneer may be applied to the outer surface of G/Z/G. This thin veneer contains the contact damage, provides aesthetics, prevents unwanted wear of opposing natural dentition, and allows for adjustment on the occlusal surface. Any occlusal-surface contact damage will be confined within the thin veneer layer, because cracks are unlikely to propagate from a low modulus, low toughness porcelain to a high modulus, high toughness Y-TZP (Kim et al. (2006) J Biomed Mater Res B Appl Biomater 79(1): 58-65). The unique structure of G/Z/G, including a surface aesthetic residual glass layer, a graded glass-zirconia layer, and a dense interior Y-TZP layer allows for a thin veneer. The thickness of the surface aesthetic glass layer varies from 5 to 50 μm, depending on the fabrication conditions. Although the glass-zirconia graded layer has limited translucency due to its high crystalline content, it provides a gradual transition in translucency from the highly translucent porcelain veneer and surface residual glass layer to the opaque Y-TZP interior, which allows for the optical depth necessary in creating the right aesthetic outcome. Alternatively, color stains can be applied to the surface of the outer residual glass layer of G/Z/G using a powdered glass slurry that has similar composition to the infiltrated glass. This staining technique has been used on the Empress system to improve the aesthetic outcome of a single colored pressed block of glass-ceramic and is well established in aesthetic dentistry. [0032] The present invention provides a uniform graded layer on both top and bottom surfaces of Y-TZP plates using glass infiltration technique. This technique can be readily used to fabricate graded structures on surfaces of orthopedic and dental prostheses with complex geometry ( FIG. 6 ). [0033] An objective of the invention is to develop robust, aesthetic, thin ceramic crowns and bridges for less invasive posterior restorative protocols. A G/Z/G material offers better resistance to flexure-induced damage, better aesthetics, and better veneering and cementation properties than bulk Y-TZP. A G/Z/G material eliminates sharp boundaries in veneered Y-TZP prostheses, which may lead to delamination of the porcelain veneer due to the dissimilar physical and mechanical properties of porcelain and Y-TZP. The residual glass and the glass containing graded layer on the internal side of G/Z/G offers robust adhesive bonding using, for example, etching-silane techniques rather than a traditional grit-blasting procedure. A traditional grit-blasting procedure may induce damage on the internal side of a dental restoration, resulting in strength degradation (Zhang et al. (2004) Journal of Biomedical materials research 71B(2): 381-6; Zhang, Y., B. R. Lawn, et al. (2006) The International Journal of Prosthodontics 19(5): 442-8). With an increase in resistance to flexural damage, the absence of grit-blasting damage, and the aid of adhesive cementation, the overall strength of the G/Z/G restoration is much higher than current veneered zirconia restorations. In addition, the current fixed partial dentures (FPDs) with Y-TZP framework often fracture from the lower portions of the connectors, leading to chipping or delamination of the porcelain veneer. A G/Z/G structure provides improved aesthetics, which allows for a FPD design without porcelain veneering in the lower portions of the connectors, improving the flexural damage resistance of PFDs. Finally, the residual glass at the G/Z/G surfaces acts as an encapsulation layer that may impede water absorption and prevent hydrothermal degradation of interior Y-TZP (Piascik et al. (2006) J. Vac. Sci. Technol. A 24(4) 1091-5). This can lead to the development of strong yet aesthetic ceramics for posterior inlays, onlays, crowns and bridges. Fracture Mechanics Analysis [0034] Damage in brittle ceramics loaded with a cylindrical or curved indenter was explored in detail in the late 1800s by Hertz who described characteristic fracture patterns called Hertzian or classical cone cracks (Hertz (1882) J. Reine und Angewandte Mathematik 92:156-171; Hertz (1896) Hertz's Miscellaneous Papers. London, Chs. 5,6: Macmillan). Intense research concerning damage modes in brittle coatings on compliant substrates loaded on the top surface, emulating ceramic crowns on dentin, began in the late 1980s. Most of the tests were done under single-cycle loading with a hard sphere indenter. Several damage modes, summarized in FIG. 7 were identified and analyzed. They can be divided into two categories: top-surface (occlusal-surface) damages from near-contact stresses, and bottom-surface (cementation internal surface) damage from far-field flexural stresses. [0035] Near-contact occlusal-surface fracture modes in brittle materials, including outer cone cracks and median cracks, formed by precursor quasiplastic deformation. Outer cone cracks (O, FIG. 7 ) initiate just outside the indenter contact area where the maximum tensile stress of Hertizan stress field occurs. Quasiplastic deformation forms beneath the indenter, producing grain boundary microcracks which coalesce and evolve into occlusal-surface median cracks (M, FIG. 7 ). For brittle dental ceramics like porcelain and alumina, classical cone cracks dominate. [0036] Far-field cementation internal surface radial fractures (R, FIG. 7 ) result from tensile stresses generated during loading. Radial cracks are oriented normal to the plate surface and are susceptible to any flexural tensile stresses generated during function. Therefore, once initiated, they propagate sideward and upward, ultimately leading to fracture (Kelly (1999) The Journal of Prosthetic Dentistry 81(6): 652-61). In dental crowns, radial cracks are clinically evidenced as bulk fracture which is believed to constitute the primary mode of failure of all-ceramic crowns. The load to initiate these internal surface radial cracks (P r ) depends strongly on thickness and elastic modulus of the ceramic and substrate and is given by P r =Bσ c d 2 /(log E c /E s ), where B is a constant, σ c is the flexural strength of the material, d is the ceramic layer thickness, E c is the elastic modulus of the ceramic, and E s is the elastic modulus of the supporting substrate. [0037] Extensive testing of porcelains, aluminas, zirconias, and glass ceramics on compliant structures have provided the data that has ultimately lead to fundamental relationships concerning loads to damage initiation for outer, median, and radial cracks for this broad array of ceramic layers on compliant structure for clinically relevant thickness under single-cycle loading. While there is competition for all outer, median, and radial modes to develop, in general radial cracks are likely to initiate first in thin sections (<0.8-1.0 mm), outer and median to develop first in thicker sections. The next goal is to develop a material with improved resistance to all these damage modes and wear while not increasing the hardness, elastic modulus, and fracture toughness of the surface of the prostheses, to avoid excessive wear of the opposing tooth or crown. Damage Resistance of FGMs [0038] The theoretical framework concerning frictionless normal indentation of elastically graded materials from a point load or from different indenter geometries has been developed by Giannakopoulos and Suresh. Explicit analytical expressions have been developed to relate the indentation load P to the penetration depth h, the contact radius a, and contact pressure p 0 , for a Young's modulus E which varies with depth z beneath the indented surface. Theory predicts that when the elastic modulus increases with depth, the stress fields for the power-law case are focused more in the interior than for the corresponding exponential case. Experimental studies showed when glasses infiltrate into a dense ceramic surface, the Young's modulus variation from surface to interior is best described by the power-law relation E=E 0 z k , where E 0 is the reference Young's modulus at the surface and k is a dimensionless constant (Jitcharoen et al. (1998) Journal of the American Ceramic Society 81(9): 2301-8). Such elastic variation effectively transfers the maximum contact stresses into interior upon occlusion, resulting in much improved resistance to quasiplastic deformation and brittle fracture at or in the vicinity of the occlusal surface. [0039] When a ceramic plate mounted onto a less stiff substrate (tooth-dentin) is subjected to loading from the top surface with a sphere indenter, the bottom surface of the ceramic plate experiences a maximum tensile stress which can result in bottom surface R cracking ( FIG. 7 ). Finite Element Analysis (FEA) of FGMs with an increasing elastic modulus from the bottom surface to interior shows that the maximum tensile stress could be lowered by 20% compared to its bulk ceramic counterpart, even if the graded layer at the ceramic bottom surface is only 200 μm thick (Huang et al. (2007) J Mater Sci Mater Med 18(1):57-64). This is because the FGM at the bottom surface spreads the maximum tensile stresses from the surface into the interior. Therefore, if both top and bottom ceramic surfaces are graded, the damage modes shown in FIG. 7 can all be suppressed. [0040] Ceramic crowns are vulnerable to near-contact and far-field flexure induced fracture from concentrated loading. Their vulnerability is exacerbated by damage, fatigue loading, and moisture. Although there has been immense amount of study concerning the fracture of ceramic crowns, the bulk of the work reported in the literature has focused on simple flexural strength tests under monotonic loading (Guazzato et al. (2004) Dental Materials 20: 449-456; Guazzato et al. (2004) Biomaterials 25: 5045-5052) or residual strength measurement following cyclic fatigue using load-to-fracture crushing test (Jung et al. (2000) Journal of Dental Research 79(2): 722-31; Stappert et al. (2005) Journal of Prosthetic Dentistry 94(2): 132-139). These tests may not accurately predict the lifetime of real ceramic crowns, because most dental ceramics are susceptible to moisture assisted slow crack growth, which can result in a reduction in strength by 50% or more over a year or so (Zhang et al. (2004) Journal of Biomedical Materials Research 69B: 166-72). Also, ceramics are susceptible to cumulative mechanical damage during contact loading. It is important to systematically analyze fracture modes and damage evolution in ceramic layers in clinically-relevant testing—namely cyclic loading beneath a spherical indenter in a wet environment. A new damage mode, inner cone fracture, has been identified ( FIG. 7 ). It is now well-appreciated that crack initiation and evolution is complex. Competing failure modes may develop on different surfaces, at different stages, and may interact depending on ceramic properties, layer thicknesses, and loading conditions (Zhang et al. (2005) Journal of Materials Research 20(8): 2021-9). Glass/Zirconia/Glass Structure [0041] A G/Z/G structure offers better resistance to flexure induced damage ( FIG. 4 ), better aesthetics, and better veneering and cementation properties over bulk Y-TZP. G/Z/G eliminates sharp interfaces in veneered Y-TZP prostheses, which may ordinarily lead to delamination of the porcelain veneer due to the dissimilar physical and mechanical properties of porcelain and Y-TZP (Sundh et al. (2004) Journal of Oral Rehabilitation 31(7): 682-8; Vult von Steyern et al. (2006) Journal of Oral Rehabilitation 33(9): 682-9; Wood et al. (2006) J. Prosthet. Dent. 95(1): 33-41). The residual glass and the glass containing graded layer on the internal side of G/Z/G offer great potential for adhesive bonding using etching-silane techniques rather than the current grit-blasting procedure, which induces damage on the internal side of a dental restoration, resulting in strength degradation (Zhang et al. (2004) Journal of Biomedical Materials Research 69B: 166-72). With an increase in resistance to flexural damage, the absence of grit-blasting damage, and the aid of adhesive cementation, the overall strength of the G/Z/G restoration is much higher than current veneered zirconia restorations. In addition, the current fixed partial dentures (FPDs) with Y-TZP framework often fracture from the lower portions of the connectors, leading to chipping or delamination of the porcelain veneer. G/Z/G has improved aesthetics, which allows for a FPD design without porcelain veneering in the lower portions of the connectors, improving the flexural damage resistance of PFDs. Finally, the residual glass at the G/Z/G surfaces acts as an encapsulation layer that may impede water absorption and prevent hydrothermal degradation of interior Y-TZP (Piascik et al. (2006) J. Vac. Sci. Technol. A 24(4) 1091-5). This allows strong yet aesthetic ceramics for posterior inlays, onlays, crowns, and bridges. [0042] The invention is further illustrated by the following Examples which are intended to be illustrative of the invention. Those of skill in the art may vary many experimental parameters within the scope of the appended claims. Example 1 [0043] Green compacts were formed from a yttria-stabilized zirconia powder, 5.18 wt % Y 2 O 3 , 0.25 wt % Al 2 O 3 , and a mean particle size of diameter approximately 28 nm with a specific surface area of 16 m 2 /g (TZ-3Y-E grade, Tosoh, Tokyo, Japan) using a cold isostatic press at 172 MPa (25 kpsi). The green compacts were presintered at temperatures between 1100 and 1400° C. for 1 hour in air. Infiltration and densification were carried out at 1450° C. for 2 hours using a custom developed glass-ceramic powder of the type described above. A heating and cooling rate of 800° C./hour was employed. Two glass-ceramic compositions were prepared for infiltration of Y-TZP. The glass-ceramic powder composition 1 consisted of the following main oxides (i.e. at 1.0 weight percent or more): SiO 2 (67.25 wt %), Al 2 O 3 (10.83 wt %), K 2 O (9.22 wt %), Na 2 O (6.61 wt %), CaO (2.68 wy %), Tb 4 O 7 (1.84 wt %), BaO (1.02 wt %), and a small amount of MgO. The glass-ceramic powder composition 2 consisted of SiO 2 (67.42 wt %), Al 2 O 3 (11.42 wt %), K 2 O (9.12 wt %), Na 2 O (6.29 wt %), CaO (2.74 wt %), Tb 4 O 7 (1.51 wt %), BaO (1.19 wt %) and a small amount of Ce 2 O 3 . [0044] Optical microscope images of G/Z/G fabricated from presintered bodies using glass-ceramic composition 1 are shown in FIG. 2 . Graded layers at both surfaces of G/Z/G plates are approximately 60 and 150 μm thick for 1400 and 1100° C. presintered specimens respectively ( FIGS. 2 a and b ). Higher magnification SEM (inserts of FIG. 2 b ) revealed that the graded layer consists of a high glass content (approximately 40 vol. %) whereas the interior comprises dense Y-TZP. A thin aesthetic residual glass layer is observed on the surfaces of G/Z/G FGMs ( FIG. 2 c ); typically being <10 μm for 1100° C. presintered and <30 μm for 1400° C. presintered specimens respectively. Example 2 [0045] A standard three-point bending test with a span of 20 mm was used to fracture rectangular bar specimens at a crosshead speed of 1 mm/min on a computer-controlled universal testing machine (model 5566, Instron Corp., Canton. MA). Flexural strength, σ, was determined using the equation below for homogeneous zirconia and for the two G/Z/G compositions fabricated from infiltrating 1400° C. for 1 hour presintered Y-TZP with in-house prepared glass-ceramic powders (composition 1 or 2) at 1450° C. for 2 hours: [0000] σ=3 Pl/ 2 wb 2 [0000] where P is the breaking load; l is the test span; and w and b are the specimen width and thickness, respectively. Flexural strengths of the two G/Z/G compositions and the homogeneous zirconia control are reported in Table 1. Data are presented in the form of mean and standard deviation (mean±SD) for a specimen size n=6. As can be seen, flexural strengths for G/Z/G infiltrated with glass-ceramic composition 1 and 2 were approximately 43% and 47%, respectively, higher than those for homogenous Y-TZP specimens. 1-sample t-test showed that it was highly unlikely (p<0.001) that a sample as strong as G/Z/G could have been sampled from the population of homogeneous Y-TZP. [0000] TABLE 1 Flexural strength data of the two G/Z/G compositions fabricated from infiltrating 1400° C. for 1 hr presintered Y-TZP with in-house prepared glass-ceramic powders (composition 1 or 2) at 1450° C. for 2 hr and their homogeneous Y-TZP counterpart. Flexural strength, σ, MPa Specimens (mean ± SD) G/Z/G (infiltrated with glass-ceramic composition 1) 1443.8 ± 252.2 G/Z/G (infiltrated with glass-ceramic composition 2) 1485.8 ± 186.5 Homogeneous Y-TZP 1012.7 ± 158.5 Example 3 [0046] Ceramic plates were epoxy bonded to polycarbonate bases and loaded on the top surface, emulating ceramic dental crowns on tooth dentin support subjected to occlusion or ceramic liner on polyethylene backing subjected articulation in total hip replacement. Critical loads for the onset of ceramic bottom surface radial cracking (an indication of flexural strength of the ceramic plates) were measured for homogeneous zirconia and for G/Z/G (d=1.5 or 0.4 mm) fabricated from infiltrating 1400° C. for 1 hour presintered T-YZP with an in-house prepared glass-ceramic powder (composition 1) at 1450° C. for 2 hours. Six specimens (n=6) were fabricated from two different batches for each G/Z/G thickness: 20×20×1.5 mm 3 or 20×20×0.4 mm 3 . Variations in critical loads between specimens fabricated from the two different batches were similar to those prepared from the same batch, being typically approximately 10%. As shown in FIG. 4 , critical loads for G/Z/G infiltrated at 1400° C. for 1 hour presintered Y-TZP were approximately 30% higher than those for homogenous Y-TZP for 1.5 mm specimens, while critical loads for G/Z/G fabricated at the same condition was almost twice that of those for bulk Y-TZP when the specimen thickness was reduced to 0.4 mm. Again, 1-sample t-test showed a significant omnibus test results (i.e. p<0.001) for both thicknesses. [0047] FIG. 3 provides XRD spectra of (a) homogenous Y-TZP sintered at 1450° C. for 2 hours; (b) Y-TZP presintered at 1100° C. for 1 hour; and (c) G/Z/G frabricated from infiltration and densification of presintered (1100° C. for 1 hour) at 1450° C. for 2 hour. T: tetragonal zirconia phase, and G: amorphous glass phase. Note that no secondary crystalline phase exists in G/Z/G FGMs. Spectra were acquired using CuKα radiation with a scan rate of 1°/min and a step size of 0.2°. Example 4 [0048] Using a glass-ceramic powder, initial infiltration conditions to fabricate G/Z/G structures in the thickness necessary for dental applications were determined. Preliminary data show that silica based glass has a limited permeability in dense Y-TZP even at approximately 1450° C., which is similar to the sintering temperature of this material. In addition, post-sintering glass infiltration at this temperature could result in grain growth and/or destabilizing of the tetragonal phase, which are known to be deleterious for hydrothermal stability of Y-TZP in the body (Chevalier (2006) Biomaterials 27: 534-43; Chevalier et al. (1999) Journal of the American Ceramic Society 82(8): 2150-4). Therefore, it is preferred to infiltrate the presintered Y-TZP and to combine infiltration and densification in one process. Thereby, the thickness of the graded glass-zirconia layer can be controlled by the porosity of presintered bodies, and combining infiltration and densification in one process can avoid grain growth and destabilizing of the tetragonal phase. [0049] Green compacts were formed from a yttria-stabilized zirconia powder, 5.18 wt % Y 2 O 3 , 0.25 wt % Al 2 O 3 , and a mean particle size of diameter approximately 28 nm with a specific surface area of 16 m 2 /g (TZ-3Y-E grade, Tosoh, Tokyo, Japan) using a cold isostatic press at 172 MPa. The green compacts were presintered at 1100 or 1400° C. for 1 hr in air. Infiltration and densification were carried out at 1450° C. for 2 hours using a custom developed glass-ceramic powder ( FIG. 1 ). [0050] FIG. 1 is a schematic diagram illustrating the processing method for the fabrication of flat G/Z/G composite: applying a powdered glass-ceramic slurry at the top and bottom surfaces of presintered Y-TZP (left), and sintering at 1450° C. for 2 hours to form a G/Z/G composite. The G/Z/G structure consists of an outer surface aesthetic residual glass layer, a graded glass-zirconia layer, and a dense interior Y-TZP. [0051] Optical microscope images of G/Z/G fabricated from presintered bodies are shown in FIG. 2 . Graded layers at both surfaces of G/Z/G plates are approximately 60 and 150 μm thick for 1400 and 1100° C. presintered specimens, respectively ( FIGS. 2 a and 2 b ). Higher magnification SEM (inserts of FIG. 2 b ) reveals that the graded layer consists of a high glass content (approximately 40 vol. %) whereas the interior comprises dense Y-TZP. A thin aesthetic residual glass layer is observed on the surfaces of G/Z/G FGMs ( FIG. 2 c ) It is typically less than 10 μm for 1100° C. presintered and less than 50 μm for 1400° C. presintered specimens respectively. [0052] One concern for G/Z/G FGMs is that the crystallization of glass, both in surface residual glass layer and in the graded layer, upon cooling, could modify the CTE and impair the aesthetics of G/Z/G. For this reason, a glass composition which exhibits excellent resistance to crystallization upon cooling was formulated. X-ray diffraction (XRD) analysis of G/Z/G FGMs revealed a small amount of glass phase in the surface residual glass and graded glass-ceramic layers and there is no detectable secondary crystalline phase present in addition to the metastable tetragonal phase, at least within the detection limit of XRD (i.e. approximately 3 vol. %) ( FIG. 3 c ). XRD spectrum of a sintered Y-TZP (1450° C. for 2 h) is shown in FIG. 3 a . In addition, no monoclinic phase is observed in either presintered ( FIG. 3 b ) or infiltrated Y-TZP specimens ( FIG. 3 c ). [0053] Critical loads were measured for polished bulk Y-TZP and G/Z/G plates (d=1.5 or 0.4 mm) fabricated from infiltrating presintered Y-TZP (1400° C. for 1 hour) with an in-house prepared glass-ceramic powder (composition 1) at 1450° C. for 2 hours. Six specimens (n=6) were fabricated from two different batches for each thickness (d=1.5 or 0.4 mm). A ˜10% variation in critical load was observed between the specimens fabricated from the two different batches. As shown in FIG. 4 , for 1.5 mm thick specimens, critical loads (mean±SD) for G/Z/G are ˜30% higher than those for bulk-Y-TZP. However, for 0.4 mm thick specimens, critical loads for G/Z/G are almost twice as high as those for bulk Y-TZP, suggesting that the impact of graded structure on the flexural damage resistance could be more significant for thin (d<0.5 mm) ceramic prostheses. Again, 1-sample t-test shows a significant omnibus test results (i.e. p<0.001) for both thickness. [0054] The appearance of G/Z/G infiltrated on partially dense bodies presintered at 1400° C. is shown in FIG. 5 , along with commercial monolithic glass ceramic Empress II (1.5 mm thick), veneered Lava zirconia (1 mm porcelain and 0.5 mm zirconia) and Cercon zirconia (1 mm porcelain and 0.5 mm zirconia). For better aesthetics, we propose to apply a thin porcelain veneer (approximately 0.3 mm thick) to the outer surface of G/Z/G. This thin veneer could contain the contact damage, provide aesthetics, prevent unwanted wear of opposing natural dentition, and allow for adjustment on the occlusal surface. Any occlusal-surface contact damage will be confined within the thin veneer layer, because cracks are unlikely to propagate from a low modulus, low toughness porcelain to a high modulus, high toughness Y-TZP (Kim et al. (2006). J Biomed Mater Res B Appl Biomater 79(1): 58-65), and the contact damage containment predictions will be examined. The thin veneer concept is supported by the unique structure of G/Z/G, which includes a surface aesthetic residual glass layer, a graded glass-zirconia layer, and an interior Y-TZP layer ( FIG. 2 ). Although the glass-zirconia graded layer has limited translucency due to its high crystalline content, it provides a gradual transition in translucency from the highly translucent porcelain veneer and surface residual glass layer to the opaque Y-TZP interior, which allows for the optical depth necessary in creating a good aesthetic outcome. Alternatively, color stains can be applied to the surface of the outer residual glass layer of G/Z/G using a powdered glass-ceramic slurry that has similar composition to the infiltrated glass. This staining technique has been used on the Empress system to improve the aesthetic outcome of a single colored pressed block of glass-ceramic and is well established in aesthetic dentistry. Example 5 [0055] Bilayer specimen fabrication. Table 2 summarizes the materials used. Bilayer specimens of G/Z/G layers on polycarbonate substrates are fabricated. The G/Z/G is based on infiltrating an in-house developed glass-ceramic into the surfaces of presintered Y-TZP (fabricated from a fine-grain Y-TZP powder, TZ-3Y-E, Tosoh, Tokyo, Japan) at the sintering temperature 1450° C. for 2 hours in air, combining infiltration and densification in one process. A structure-damage resistance relation is established under cyclic loading for this system. Polycarbonate is selected as a support material for the FGMs because it is compliant and can be considered to represent dentin or bone (though its elastic modulus is slightly lower than that of either) and is transparent, permitting direct observation of fractures evolving from or propagating to the bottom surface of the G/Z/G layer. Specimens are loaded using a 3.18 mm radius glass or WC sphere. [0000] TABLE 2 Material properties and sources. Thermal Young's expansion modulus coefficient Poisson's Brand Name Material (GPa) (° C. −1 ) ratio and Source Glass-ceramic 70 10.3 × 10 −6 0.26 In-house composition Y-TZP 210 10.4 × 10 −6 0.30 TZ-3Y-E, Tosoh Epoxy resin 3.4 — 0.33 Harcos Chemical Resin cement 3.1 Rely x ARC, 3M Polycarbonate 2.3 — 0.33 Hyzod, AIN Plastics Composite 18 Z100, 3M WC 614 — 0.30 r = 3.18 mm, J & L Industrial Supply [0056] Flat Y-TZP green compacts, fabricated from a fine-grain yttria-stabilized zirconia powder (TZ-3Y-E, Tosoh), are presintered at temperatures between 900 and 1400° C., creating zirconia plates with various porosities. The top and bottom surfaces of presintered Y-TZP are coated with a powdered glass-ceramic slurry which has a similar CTE and Poisson's ratio to those of Y-TZP (Table 2). Glass infiltration and densification is carried out simultaneously at 1450° C. for 2 hours inside a high temperature box air furnace (ST-1700C-6612, Sentro Tech Corp, Berea, Ohio). A heating and cooling rate of 800° C./hour is employed. This minimizes grain growth and/or destabilizing of the tetragonal phase associated with the post-sintering heat treatment. Both grain growth and destabilizing of the tetragonal phase are deleterious for long-term hydrothermal stability of Y-TZP in biomedical applications. G/Z/G specimens with two final dimensions are fabricated: 20×20×1.2 mm 3 or 20×20×0.4 mm 3 . In addition, by manipulating the porosity of the presintered Y-TZP body, the glass penetration depth may be controlled, creating G/Z/G structures with various thicknesses of the graded glass-zirconia layers ( FIG. 2 ). Three groups of specimens with different graded glass-zirconia layer thicknesses are fabricated for a G/Z/G of 0.4 mm total thickness, and six groups with different graded layer thicknesses for a G/Z/G of 1.2 mm total thickness (Table 3). An equal thickness of the graded layer at the top and bottom surfaces for each specimen is maintained to prevent warpage. The effect of graded layer thickness on damage resistance for G/Z/G with different thicknesses may be elaborated by comparing specimen groups G-Tn1, G-Tn2, G-Tn3 with G-Tk1, G-Tk2, G-Tk3. The effect of relative ratio of the graded layer and the total specimen thickness on the damage resistance may be examined by comparing specimen groups G-Tn1, G-Tn2, G-Tn3 with G-Tk3, G-Tk4, G-Tk5. Tn and Tk represent thin (0.4 mm) and thick (1.2 mm) specimens respectively. [0000] TABLE 3 Design parameters for G/Z/G with various thicknesses of graded layers at top and bottom surfaces. Tn and Tk represent thin (0.4 mm) and thick (1.2 mm) specimens respectively. Total G/Z/G thickness (mm) 0.4 1.2 Graded layer thickness (mm) G- G- G- G- G- G- G- G- G- Tn1 Tn2 Tn3 Tk1 Tk2 Tk3 Tk4 Tk5 Tk6 Top 0.05 0.10 0.15 0.05 0.10 0.15 0.30 0.45 0.55 surface Bottom 0.05 0.10 0.15 0.05 0.10 0.15 0.30 0.45 0.55 surface [0057] The excess glass may be ground away from the G/Z/G surfaces and the plates will be epoxy bonded (Harcos Chemicals, Bellesville, N.J.) to a 12.5 mm thick polycarbonate substrate (Hyzod, AlN Plastics, Norfolk, Va.) for single-cycle-load screen test using a spherical tungsten carbide indenter (r=3.18 mm) to determine the flexure induced damage resistance of the G/Z/G cores. Only the two strongest groups (requiring higher loads to fracture) from the single-cycle-load screen results for each specimen thickness 1.2 or 0.4 mm is chosen for cyclic fatigue tests to construct the design maps. Specimens with polished internal surfaces but with residual aesthetic glass on the occlusal surface are epoxy bonded to polycarbonate substrates for fatigue tests using a spherical glass indenter (r=3.18 mm) in water. The stronger group out of the two groups subjected to cyclic fatigue test is selected to determine the effect of surface treatment on the damage resistance of G/Z/G. Specimens of 1.2 mm thick with abraded or etched internal surfaces are epoxy bonded to polycarbonate substrates for fatigue tests using a glass indenter in water. As-polished surfaces yield the intrinsic strength of FGMs but may not represent real-life conditions. Laboratory and clinical practices (e.g., particle abrasion or etching of the internal surface of all-ceramic crowns and bridges) may damage the surface. To mimic this, the ceramic bottom surface is abraded with 50 μm alumina particles for 5 seconds from a standoff distance of 10 mm using 276 KPa compressed air pressure or etched with HF solution (9.5%) for 90 seconds. Finally, the stronger group out of the two groups subjected to cyclic fatigue tests is cemented (Rely X ARC, 3M/ESPE, St. Paul, Minn.) to a 5 mm thick Z100 substrate (3M/ESPE, St. Paul, Minn.) for step-stress fatigue tests using a glass indenter in water. The internal surface of G/Z/G is abraded or etched, based on the treatment that will yield a better damage resistance from the preceding tests. To simulate the aesthetic veneer, a thin porcelain veneer may be placed on the occlusal surface of the G/Z/G structure (1.2 mm G/Z/G and 0.3 mm porcelain). Since extensive data on flat bilayer specimens have been generated, some additional flat specimens, namely Lava zirconia plate on polycarbonate and porcelain veneered Lava zirconia on Z100 substrate, are fabricated as controls to assure validity of comparisons with previous data. Example 6 [0058] GZG Test configuration. Cracks are initiated and propagated by loading the bilayer specimens (a G/Z/G layer of 1.2 mm or 0.4 mm thick on polycarbonate substrate) with a 3.18 mm radius sphere (tungsten carbide or glass). Initiation and evolution of the near-contact occlusal surface damages, namely outer cone, inner cone and median cracks, are characterized using a confocal optical microscopy (K2S-BIO, Technical Instruments, Burlingame, Calif.), viewing from the contact surface (occlusal surface) and progressively focusing down to the interior of the specimen. A cyclic loading fatigue test is performed on a mouth-motion simulator (Elf 3300, EnduraTEC, Minnetonka, Minn.) using a controlled loading profile to simulate the normal chewing function: maximum load (biting force), loading and unloading rates 1000 N/sec, and chewing frequency 1 Hz. Conventional cyclic fatigue profile (fatigue to failure with a prescribed maximum load) and step-stress fatigue testing (fatigue to failure with consecutively increasing loads) is employed to construct the design maps and to predict the performance, respectively. Fatigue testing is interrupted after each cyclic loading step and damage sustained in the G/Z/G layer is examined by confocal microscopy. Tests may be continued until failure of the G/Z/G layer. Failure is defined when one of the near-contact surface crack systems propagates through the entire G/Z/G layer or the cementation radial fracture is observed. Occasionally, specimens may be randomly selected and sectioned for cross-sectional examination using the optical microscopy and SEM to confirm the confocal microscopy observation. [0059] Using transparent polycarbonate as a substrate, initiation of the far-field radial cracks at the bottom surface of the G/Z/G layer may be imaged directly from below. This provides insight into relative order of fracture initiation for competing fracture modes as well as information about the load and the number of cycles at which near-contact surface cracks completely penetrate the specimen and the extent of any delamination that may develop at the ceramic-epoxy interface. For the internal surface radial cracks, failure is defined when the cracks pop-in because the radial cracks are several millimeters in size which is sufficient to cause the dental prostheses failure. Weibull statistics may be used for data analysis (the current standard method in materials testing). No overlap of the 90% confidence bound is considered as significant. Example 7 [0060] Fractography. The fracture surface of randomly selected G/Z/G is analyzed to determine the effect of a glassy phase on crack path in the graded Y-TZP at grain level. A thin layer of carbon is deposited on the fracture surface at a 90° incident angle using a carbon coating unit (EMITECH, K250). The fracture surface is examined in an environmental SEM (Hitachi 3500N) equipped with an energy-dispersive spectroscopy (PGT IMIX) and a backscatter electron imaging detector. Both secondary and back scattered electron imaging modes are utilized to reveal the crack-microstructure interaction. For comparison, crack paths in homogeneous Y-TZP ceramics are examined. In addition, controlled cracks and damage are produced in glass-zirconia graded layers and the dense Y-TZP layer using both Vickers and Hertizan indentations. Crack tip-microstructure interaction and quasiplastic deformation of graded structures are investigated compared to homogeneous Y-TZP. (Guiberteau et al. (1993) Philosophical Magazine A 68(5): 1003-16; Guiberteau et al. (1994) Journal of the American Ceramic Society 77(7): 1825-31; Cai et al. (1994) Journal of Materials Research 9(3): 762-70; Zhang et al. (2003) Journal of Materials Science 38(6): 1359-64). [0061] While the present invention has been set forth in terms of specific embodiments thereof, it will be understood that numerous variations upon the invention are now enabled to those skilled in the art, which variations yet reside within the scope of the present teachings. Accordingly the invention is to be broadly construed and limited only by the scope and spirit of the present disclosure.

The present invention provides a functionally graded glass/ceramic/glass sandwich system for use in damage resistant, ceramic and orthopedic prosthesis. The functionally graded glass/substrate/glass composite structure comprises an outer residual glass layer, a graded glass-ceramic layer, and a dense interior ceramic. The functionally graded glass/substrate/glass composite structure may further comprise a veneer on an exterior surface. The present invention also provides a method for preparing a functionally graded glass/ceramic/glass sandwich system. A powdered glass-ceramic composition is applied to the accessible surfaces of a presintered zirconia substrate to thereby substantially cover the substrate surfaces. The glass of the composition has a CTE similar to that of the substrate material. The glass-ceramic composition is infiltrated into and densifies the substrate by heating the assembly to at least the sintering temperature of the substrate.

This invention was made with Government support under Contract No. NAS7-1260 awarded by the National Aeronautics and Space Administration. The Government has certain rights in this invention. FIELD OF THE INVENTION This invention relates to millimeter wave devices, and, more particularly, to a housing or package for such devices. BACKGROUND Millimeter wave devices employ a monolithic microwave integrated circuit device or “MMIC” as an active element and operate at very high frequencies, 45 Gigahertz to 120 Gigahertz and higher. The devices may be configured as amplifiers, oscillators and the like electronic devices to perform functions at those high frequencies akin to those functions accomplished at lower frequencies with more familiar amplifier and oscillator architecture. Such millimeter wave devices find application, as example, in MMW radiometers. The elements of the device are physically quite small. At a frequency of 120 Ghz, one wavelength measures a mere one-quarter of a centimeter in length or slightly less than one-tenth of an inch. MMW devices thus are physically small in size, and its components, including one or more MMIC's, are much smaller still. Although small in size, unlike lower frequency apparatus, the physical dimension of the MMIC, the associated electronic components and the electrical lead wires are large in respect to the wavelength of the operating frequencies. As a consequence lead wires and the like, by which the components are wired into circuit, and even the body of the component can impact the electromagnetic characteristics of the electronic circuit defined with those elements. Thus the development of a new MMW device and the proof of the device's design is complicated by that impact. For one, it is necessary to shield the device's components and/or electrical leads. Thus it is not possible to mount all the circuit components and MIMICS on a conventional printed circuit board or place the device in a conventional housing, such as used at lower frequencies. The MMW signals in one part of the circuit must be limited to propagating only to precisely defined routes and must not “jump” that route and propagate in undesired ways to parts of the circuit where they would cause interference. As example, because the wavelength is so short, a small electrical lead from a component or interconnection may serve as a full wave or half-wave antenna, and radiate MMW energy from that lead into open space. Other electrical leads in the circuit could likewise act as a full-wave or half-wave receiving antenna, picking up the foregoing radiation. As more specific example, in the familiar superheterodyne type receiver, a mixer receives MMW energy from an external source and mixes the received signal with another MMW signal supplied by a local oscillator to produce a lower difference frequency or “beat” signal, as variously termed, a process called down-converting. The downconverted signal is then coupled to an IF amplifier, which amplifies that signal. If, however, through the spurious radiation process described, the MMW signal is also coupled to the output of that mixer by means of a spurious path, the mixer's output contains not only the IF signal, but an interfering MMW signal. The combination of those two signals may overload the succeeding IF amplifier. Then too, the two signals may beat together in the IF amplifier creating still additional interference signals. To avoid such spurious signals, it is necessary to essentially shield each component from every other component in the MMW device. The MMW device's housing or packaging provides that shielding. Thus, to house the active MMIC semiconductor device and the ancillary capacitors and resistors, the practice has been to use a thick metal plate that has been machined to form precisely defined compartments or hollow cavities, referred to as “mouseholes”, within the plate's thickness or depth, and provide additional small passages for the interconnecting leads to those elements. The mouseholes are small and narrow, consistent with the small physical size of the components. The active MMIC devices are formed on substrates. And the MMIC devices and the other electrical components are dropped into their respective mousehole, and fastened in place, suitably with an epoxy adhesive. The open side of the housing is covered with a metal lid, closing the mouseholes. Typically, machining of the housing to shape is accomplished using Electron Discharge Machining apparatus. That apparatus has the ability to maintain very tight dimensional tolerances and produces cavities with sharply defined square corners, which is desirable. However, discharge machining is an expensive process. As is familiar to designers of microwave and higher frequency devices, the foregoing assembly of MMW elements into the foregoing package on initial assembly of the first or prototype unit rarely, if ever, produces MMW device performance that conforms to the theoretical operation desired. Although the foregoing package solves one problem, it produces others: the cavity mode resonances. The adverse effects are due to the fact that the dimensions of the formed cavities, the mouseholes, are all on the same order as the wavelength of those frequencies for which the device is intended to function. Recalling that at 120 MHz, the wavelength is only one-tenth inch and that portions of the electrical leads are located within those cavities, the lead portion again act as an antenna or coupling and the energy radiated therefrom “excites” one or more electromagnetic modes within the respective mouseholes. A rectangular cavity is capable of supporting, that is, resonating in a number of different modes, including a primary TE01 mode and an indefinite number of higher order modes. The higher the number of the mode, the lower the maximum amplitude of the voltage or intensity. Exact mathematical representations of those modes for a given cavity are available in the technical literature. Any excited mode could cause interference and is undesirable and should be minimized or eliminated entirely. Although foreseeable, because of the complex nature of mode excitation and lead placement and the shape of the mouseholes, the precise cause of the adverse effects are unpredictable. To the present day, neither close attention to detail in fabricating the completed package or refinement in design procedures have been able to eliminate those effects. As a practical matter, the adverse effects come with the territory. Thus, following assembly of a prototype MMW device, the procedure is to hunt down and destroy those expected uninvited resonances. This is presently accomplished by inserting high frequency absorbent, “lossy”, material, such as Eccosorb material, at strategic locations in the cavities. The Eccosorb material produces an electrical loss to the incident radiation, thereby reducing or minimizing the offending mode or modes. Although intended to be identical in construction, in the absolute sense each MMW device in a production run differs in physically minute respects from others in the run. An electrical lead from a component in one device may be oriented slightly in position from the corresponding lead in the corresponding component in the next device, creating a small physical difference. However, measured against the wavelength of the frequencies employed, which is, as earlier stated, one-quarter centimeter at 120 GHz, the difference is significant. That difference results in the excitation of a different mode during operation. Thus each device produced in the run must be tested and the unique resonant modes hunted down and destroyed. Typically the design of a MMW device is confirmed or “proofed” with the production of the first prototype. Often one finds that it is not possible to sufficiently minimize the unwanted resonances in that production prototype. One must refine the design of the mousehole cavities and, essentially, construct a second iteration of a prototype. Since the components are all permanently fastened in place in the first prototype, and are nearly impossible to remove without damaging the device or the housing, one is left with the prospect of rebuilding the next prototype from scratch. That procedure means repeating the expensive machining procedure to form another metal housing and using up additional valuable MMIC devices. The foregoing is an obvious drain on resources, including manpower, and diverts those resources from more intellectually interesting goals. It begs for a more efficient and streamlined prototyping technique. MMW devices, such as radiometers, are produced in very very limited quantities and is by no means regarded as a high volume product. Thus quite often fewer than half a dozen in total are produced for a customer. If two or more prototypes need to be produced in order to attain the stage of desired performance, performance that excludes the unwanted resonances, the added development expense can be amortized only over the production run of six, in the example given. And that significantly raises the ultimate per unit cost of MMW devices in the production run. Accordingly, a principal object of the invention is to simplify and more efficiently develop microwave millimeter wave devices. A further object of the invention is to provide a new housing or package that simplifies construction of satisfactory prototype millimeter microwave devices. An additional object of the invention is to easily eliminate excitation of unwanted cavity resonances in the housing mouseholes of the MMW device. A still further object of the invention is to develop MMW devices without requiring repetitious reconstruction of machined housing packages. SUMMARY OF THE INVENTION In accordance with the foregoing objects a package for a high frequency electronic device that employs one or more MMIC devices is formed of a base plate and a plurality of metal inserts removeably fastened to the base plate. The inserts are spaced apart and contain a profiled edge with the profiled edge in one in confronting spaced relationship with that of another of the inserts. Together with the backplate, the profiled edges define elongated cavities with the edges serving as two of the cavities side walls. The foregoing cavities serve as a repository for the MMIC devices and some of the additional components and stripline. The side walls capture at least a portion of the discrete components, including capacitors, resistors, MMIC's. As an additional aspect, passages are also formed through the inserts, spaced from the profiled edges, to serve as compartments for containment of additional electronic components and allowing those components to be secured directly to the back plate. Shallow grooves defined in the underside surface of the inserts provide passages between the compartment and the cavity, permitting electrical leads from the components to connect with other components and/or MMIC devices installed in the cavity. The foregoing invention eliminates the need inherent in the prior MMW device packaging of placing substrates and other electronic components into vary narrow cavities, mouseholes, formed in the packaging to prevent appearance of higher order cavity resonances. With the invention, the RF and DC components of the MMW device are placed directly in the module, which reduces the MMW device's assembly time. The cavity size is determined by the dimensions of the metal insert, not, as in the prior devices, by a cavity machined into the integrated module assembly (IMA) housing. Tight dimensional tolerances requiring electron discharge machining apparatus characteristic of the prior MMIC housings are eliminated. The foregoing construction permits easy re-machining or replacement of an improperly sized or out of tolerance cavity. Following adhesive fastening of the MMIC's, substrates, and other electronic components in place in the housing, the metal inserts can be removed, remachined, and reinstalled allowing adjustment of the cavity size to eliminate undesired cavity oscillations that may have been introduced by installation those electronic components. The MMIC's, substrates and other electronic components remain in place undisturbed on the housing during such adjustment. The foregoing and additional objects and advantages of the invention together with the structure characteristic thereof, which was only briefly summarized in the foregoing passages, becomes more apparent to those skilled in the art upon reading the detailed description of a preferred embodiment, which follows in this specification, taken together with the illustration thereof presented in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 shows the new package in an exploded view; FIG. 2 shows three of the elements of the embodiment of FIG. 1 in assembled relationship in top view; FIG. 3 shows the elements of FIG. 2 in a bottom view; FIG. 4 illustrates a bottom view of the cover used in the foregoing embodiment; FIG. 5 is a block diagram of the radiometer front end that is to be housed in the package of FIGS. 1-4, identifying the various electronic functions of the components; and FIG. 6 is an enlarged partial view of one of the elements shown in FIGS. 2 and 3 used to assist the reader to understand a benefit of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A MMW device package is best described in connection with a radiometer application, more particularly a front end unit for a radiometer, such as illustrated in exploded view in FIG. 1 . The package contains a metal base or base plate 1 , three smaller individual plates, referred to as inserts, 3 , 5 , and 7 , and, optionally, a metal cover plate or cover 9 , which, as assembled, are sandwiched together in a unitary assembly. The inserts, though physically separate from one another, are illustrated arranged in a common plane, as they would appear when assembled to base plate 1 , with confronting edges spaced from each other. Base plate 1 contains six small cylindrical shaped guide pins 11 , 13 , and 15 , suitably two guide pins for each of the three inserts to aid in positioning the inserts on the surface of the base plate. Each of the inserts contains guide holes extending through the insert's thickness, such as guide holes 12 in insert 3 , guide holes 14 in insert 5 and guide holes 16 in insert 7 . By design those guide holes correspond in spacing and position with associated guide pins on the base plate. Ideally those guide pins are located to an accuracy of one mil or better and enter the guide holes in the inserts with a slip fit. To fasten the inserts in place, the base plate also contains a series of threaded bolt passages 19 , 21 , and 23 , suitably three for each of the inserts. The inserts contain bolt passages there through at locations that correspond in spacing and position with associated threaded bolt passages on the base plate. Thus bolt holes 20 are included in insert 3 , bolt holes 22 are contained in insert 5 and bolt holes 24 in insert 7 . Suitably the top end of those bolt passages is of wider diameter to accommodate and receive the bolt head in order that the bolt head does not protrude above the upper surface of the associated insert. With the inserts positioned on the associated guide pins in the base plate, bolts 9 , only one of which is illustrated, are screwed into place to securely fasten the inserts in place to the base plate. This is a removable fastening, which is used to advantage to permit the insert to be removed and replaced, as later herein described. Following installation of all electrical components and MMIC' devices, not illustrated, but later herein discussed, onto the base plate and fastening down of the inserts, the cover 9 is welded in place atop the inserts. For in-flight use in a radiometer, the cover, alternatively, may be screwed to those inserts, in which case the inserts would be modified to incorporate threaded bolt holes on the upper surface. The cover provides a shield at the open side of the cavities for the enclosed electronic components. As assembled, the three inserts are spaced apart from each other on the upper surface of base plate 1 , with the confronting side edges of those inserts defining therewith three passages or cavities 27 , 29 and 31 that intersect at a junction. This is better illustrated in the top and bottom views of FIGS. 2 and 3, next considered. Reference is made to the top view of FIG. 2, which shows the three inserts 3 , 5 , and 7 in assembled relationship, properly spaced. Cavity 27 is defined between the confronting spaced edges 28 and 30 , of inserts 3 and 5 , respectively. Another cavity 31 is defined between the confronting spaced edges 32 and 34 of inserts 5 and 7 , respectively. And the third cavity 31 is defined between the confronting spaced edges 38 and 40 of inserts 7 and 3 , respectively. Those confronting insert edges bordering portions of the inserts periphery are contoured or profiled, as variously termed, and serve as cavity walls to the adjoining cavity. Those walls are parallel to one another and, when assembled, are perpendicular to the base plate surface, the latter of which serves as a bottom cavity wall. By design the guide pins in the base plate are perpendicular to the surface of the base plate in order to maintain the profiled edges of the inserts in parallel and oriented perpendicular to the base plate. The cavity's height is essentially equal to the thickness or depth of the inserts, which are preferably of equal thickness. The cited cavities intersect at a common junction or location as illustrated. Although the elongate cavities are made as narrow as possible to accommodate microwave strip line conductors, the cavity is widened at various locations along its length, as example at 41 where a complementary rectangular shape slots in opposed edges of the inserts define a wide rectangular area in cavity 27 . This wider area is necessary to physically accommodate a MMIC chip, which is larger in size than the narrow portion. In this embodiment, cavity 27 contains three additional wide rectangular shaped spaces. Likewise, cavity 31 accommodates three MMIC amplifiers in respective ones of the three rectangular spaces, such as 43 , and cavity 29 contains two such large rectangular spaces, such as 45 . As earlier mentioned, the housing is for a front end of a radiometer, illustrated in FIG. 5, later discussed, and that front end includes a mixer, an active MMIC element. That mixer is positioned at the intersection of the three cavities, enabling the mixer to receive RF signals inputted via cavities 27 and 29 , and provide an output into cavity 31 . To accommodate that mixer, the ends of the three cavities are also widened sufficiently. Guide pins 11 properly locate insert 3 on the base plate relative to the other inserts. Likewise guide pins 13 properly locate insert 5 and guide pins 15 properly located insert 7 to the requisite position and spacing, wherein the width of the passage is of the desired dimension. The inserts are then screwed into place. In addition to forming the cavity wall, the inserts also contain cut-out sections or, as variously termed, large sized through-hole passages to provide pockets or compartments in which to mount the bypass capacitors and resistors that set the bias conditions for the respective MMIC chips installed in the respective cavities. Insert 1 contains compartment 42 , 44 , 46 and 48 and also a large rectangular compartment 50 . Insert 4 in this embodiment contains five compartments 52 , only one of which is numbered, and insert 7 contains one compartment 54 . The compartments extend through the insert, from top to bottom. As shown in the bottom view of FIG. 3 to which reference is made, those compartments open on the bottom side, allowing the upper surface of base plate 1 , when assembled to the inserts, to serve as the compartment's floor. As is visible in FIG. 3, a short shallow narrow groove 49 formed on the underside of insert 3 extends between compartment 44 and elongated cavity 27 . The groove serves as a passage for the electrical leads from the component disposed within compartment 44 and those components or devices located within the elongated cavity. With the component installed in the portion of the baseplate 1 that underlies compartment 44 in insert 3 , its electrical leads are routed through the groove passage 49 to an appropriate electrical connection on the associated MMIC chip that is disposed in the cavity 27 . To the left, three lead grooves, only one of which 56 is labeled, extend between compartment 50 and spaced positions along elongated cavity 31 . Other like grooves extend between the other compartments illustrated and the adjacent cavity and serve like function. Thus lead groove 51 is associated with compartment 52 in insert 5 , and additional lead passages, not numbered extend between the illustrated compartments, not numbered in insert 3 and cavity 27 . Along the side of insert 5 , lead groove 53 extends between compartment 52 and cavity 29 , and another like groove, spaced therefrom also extends between another side of that compartment and cavity 29 . Insert 7 contains a lead groove 55 extending between compartment 54 and cavity 29 . Returning to FIG. 1, the inserts collectively fit within the upper surface area of base plate 1 . Apart from the profiled edge along two portions of the inserts periphery, the outer periphery of insert 3 is straight so as to be flush with outer edges of the base plate, which is rectangular shape in this embodiment. Likewise two of the edges insert 5 and two of insert 5 are also straight and oriented at right angles to one another for the same reason. With cover 9 , the inserts and the base plate sandwiched together, the package defines a rectangular geometry of short height that may be fitted within a predefined slot-like compartment in other equipment, not illustrated. Reference is made to FIG. 4, providing a view of the underside of cover 9 . Ideally, the top and bottom side surfaces of cover 9 should be flat. However, when, as in the present embodiment, it is desired to limit the total thickness or height of the package to a predetermined dimension governed by space available in the external equipment, the thickness or height of the inserts 3 , 5 and 7 might be smaller than the height of the MMIC devices installed in some of the compartments, such as those MMIC devices disposed in compartments 41 in passage 27 and compartments 34 in passage 29 , shown to the left in FIG. 2 . To accommodate that excess in the component's height, appropriate grooves are formed in the underside surface of cover 9 . Thus, as illustrated, the cover contains an elongate cavity 27 ′ containing compartments 41 ′ and an elongate cavity 29 ′, which insects cavity 27 ′, containing compartments 34 ′ formed by shallow grooves. For convenience the foregoing cavities are identified by the same numbers as the corresponding cavities and compartments defined in inserts 3 and 5 in FIG. 2, but primed. The foregoing cavities and their included compartments formed in the cover overlay and cover the mating cavities and compartments defined in inserts 3 and 5 . This may be visualized by inverting FIG. 4 and applying it over the top view of the inserts in FIG. 2 . Suitably, the metal used to form the foregoing base plate, inserts and cover is the well known A-40 material, an aluminum silicon compound, which is light in weight, of high thermal conductivity and is easily machined. That material also allows direct attachment of MMIC chips and fused silica substrates directly to the floor of the housing, the base plate. Preferably the A-40 metal is plated with a Nickel Gold plating, a Nickel layer followed by a Gold layer overlay to enhance the surface's electrical conductivity. Returning to FIG. 2, it is appreciated that the projection of the three inserts 3 , 5 and 7 onto the base plate 1 defines a pattern for the regions of the base plate left uncovered, the regions underlying the component compartments and the elongated cavities. That pattern may be marked onto base plate 1 in any convenient way. Further, the foregoing pattern may be enhanced by manually adding to it, the outline of the various lead grooves, earlier described in connection with FIG. 3 formed on the back side of the inserts. With that pattern, the electrical components, MMIC devices and leads may be directly installed in place on the base plate 1 within the regions of the pattern defined by the outlines of the respective compartments, cavities and grooves. The RF/DC bias circuitry and local oscillator components are all located on the same side of the housing. The technician may assemble and wire bond those elements together in circuit without being physically constrained by the side edges or compartment walls of the inserts. Thus wire bonders may easily be positioned and used to wire bond electrical components in the desired circuit arrangement. Thereafter the inserts may be placed in position and fastened in place, making minor adjustments as necessary to the position of the leads. Alternatively, the technician may install one or more of the inserts in place and then mount the components, MMIC chips and leads in place. An initial benefit of the foregoing construction is apparent. The compartments expose an area of the underlying base plate. That exposed area or floor serves as a fastening location for the electrical components located in the compartment. The components are typically adhesively joined by epoxy to the exposed base plate area underlying the associated pocket firmly holding the components in place. Once bonded, removal of the components is very difficult. The electrical leads from those components are extended into the cavity area through the bottomless lead grooves. Should it be desired to remove the insert for any reason, such as elsewhere herein discussed, once the screws attaching the insert to the base plate are removed, the insert may be lifted off of the base plate, leaving the electrical component and leads undisturbed and in place. The insert may thereafter be replaced in position and screwed back in place as those components and leads remain in proper alignment with the openings in the insert. The foregoing housing construction offers faster and more efficient assembly operation. The technician need only place a pattern of the cavities, pockets and lead routings on the base plate, and then proceed to mount all of the electronic components and stripline within the confines of that pattern, including bonding all the electrical connections. Thereafter, the technician may install the inserts in place. With the new package, the technician is no longer burdened by the tedious and time consuming task of wire bonding connections in physically small mouseholes using wire bonders not designed for that purpose. It is found that the smallest size wire bonder tip available is still larger than desired for the small size confines of a mousehole; and due to the lack of volume production of MMW devices using the prior housing design, no incentive for the wire bonder manufacturer to develop physically smaller bonding tips and make them available at a reasonable price. Working with existing wire bonders in MMW device application required the technician to shoulder a near impossible burden. The present invention avoids that problem, making MMW device manufacture quicker and more efficient. A front end circuit 60 for a MMW radiometer is schematically illustrated in FIG. 5, surrounded by dash lines, together with a local oscillator module 61 in an adjacent block. Typically the radiometer's front end includes an input 62 for the received MMW signal, a low noise amplifier 63 , which comprises one or more amplifier stages, a band pass filter 64 x, a sub-harmonic mixer 65 , a local oscillator input 66 for receiving a local oscillator signal from oscillator module 61 , an amplifier 67 for that signal, whose output is coupled to a mixer input, an IF amplifier 68 , comprising one or more IF amplifier stages. In operation the signal received at input 62 is amplified, filtered and applied to one input of mixer 65 . The mixer mixes or beats that signal together with the local oscillator signal from input 66 , producing, for one, a signal of a frequency that is equal to the difference in frequency between the former to signals, called the IF signal. That IF signal is amplified and routed to output 69 , from where it is fed to other signal processing circuits, not illustrated, of the radiometer. It is appreciated that the foregoing circuit illustrates a classic frequency downconversion system. As earlier noted should the housing for the circuit be such that the signal at input 62 finds an alternative path to amplifier 68 , or should the signals from any of the devices excite a cavity mode to produce another signal, either such signal could interfere with proper operation of the mixer 65 and/or IF amplifier 68 . The mechanical aspects of the device's housing ideally must not permit the creation of adverse electromagnetic effects or should any such adverse be created, it should be easily absorbed through introduction of microwave loss material, such as Eccosorb material, into the housing. The disclosed housing satisfies that criteria. To develop an electronic device at the high frequencies employing MMIC devices, such as the radiometer front end depicted in FIG. 5, the designer determines the number of electronic components needed and ancillary thereto the size of the cavities and compartments needed in the housing. The housing is then fabricated, resulting in an initial configuration of the back plate, inserts and cover. The components are assembled together into the housing in any of the procedures earlier described. The design is then tested, recognizing that the goal is to finalize a design both electrically and physically that may be later reproduced in larger quantities. Should any undesired resonances be uncovered during test, it requires the judgment and skill of the designer to uncover its cause. Obviously, the procedure for doing so is not material to the present invention and goes beyond the scope of the specification. Accordingly, it is possible only to consider a hypothetical cause to a hypothetical problem. Reference is made to FIG. 6, which partially illustrates in greatly enlarged scale, a portion of insert 7 in FIG. 3 . Assuming the designer determines that the cause of an undesired resonance uncovered in testing is that the edge 58 of insert 7 is too high, and that shortening that edge to the height represented by dash line 59 would cure the problem. The designer simply removes cover 9 and unscrews the screws holding insert 7 in place. The insert is then handed over to a machinist with appropriate instructions. Upon return the insert, now with edge 58 , is replaced on the back plate, covered and the unit is retested. In the foregoing procedure, the electronic components remain in place adhering to the back plate. The foregoing procedure may be repeated many times until testing shows satisfactory performance. In the foregoing procedure, should it be determined that too much material was cut away, then all that is necessary to do is to replace the damaged insert with another identical one, and begin trimming anew. Once the exact dimensions of the inserts are determined for proper performance of the electronic circuit, then additional copies may be easily reproduced and used to assemble additional units of the electronic device. Modifications of the foregoing housing become apparent to those skilled in the art. As example, although guide pins are used to position the inserts, as those skilled in the art appreciate, that is a static arrangement. As an improvement, to provide greater flexibility to the package, the guide pins may be mounted, alternatively, to a conventional positioning mechanism, such as a screw and traveler, that is mounted to the underside of the base plate. By moving the positioner mechanism the associated guide pin may be adjusted in position about the base plate's upper surface, and that would change the position of the insert associated with the guide pins. By such means the spacing and relative angular orientation of the inserts may be adjusted. It is believed that the foregoing description of the preferred embodiments of the invention is sufficient in detail to enable one skilled in the art to make and use the invention. However, it is expressly understood that the detail of the elements presented for the foregoing purpose is not intended to limit the scope of the invention, in as much as equivalents to those elements and other modifications thereof, all of which come within the scope of the invention, will become apparent to those skilled in the art upon reading this specification. Thus the invention is to be broadly construed within the full scope of the appended claims.

Development of Millimeter Wave Devices containing MMIC's is expedited by use of a new package for the MMIC's and associated electrical components that define the functional circuit. The package includes a base plate and a plurality of metal inserts removeably fastened to the base plate. The inserts are spaced apart and contain a profiled edge with the profiled edge in one in confronting spaced relationship with that of another of the inserts. Together with the backplate, the profiled edges define elongated cavities, serving as two of the cavities side walls. The cavities serve as a repository for the MMIC devices and some of the additional components and stripline. Should extraneous resonances be discovered, the insert can be removed and adjusted in size and profile, and replaced, thereby adjusting the cavity without disturbing the electronic components or MMIC's which are secured to the back plate. The foregoing eliminates the restrictions imposed by the prior use of mouseholes and avoids the need for rebuilding the entire housing.

This application contains subject matter similar to subject matter disclosed in copending U.S. patent application Ser. No. 09/366,216, filed on Aug. 2, 1999, now U.S. Pat. No. 6,107,167, issued Aug. 22, 2000, and copending U.S. patent application Ser. No. 09/365,411, filed on Aug. 2, 1999. TECHNICAL FIELD The present invention relates to a method of manufacturing a semiconductor device having accurate and uniform polysilicon gates and underlying gate oxides. The present invention is applicable to manufacturing high speed integrated circuits having submicron design features and high conductivity reliable interconnect structures. BACKGROUND ART Current demands for high density and performance associated with ultra large scale integration require design rules of about 0.18 microns and under, increased transistor and circuit speeds and improved reliability. As device scaling plunges into the deep sub-micron ranges, it becomes increasingly difficult to maintain performance and reliability. Devices built on the semiconductor substrate of a wafer must be isolated. Isolation is important in the manufacture of integrated circuits which contain a plethora of devices in a single chip because improper isolation of transistors causes current leakage which, in turn, causes increased power consumption leading to increased noise between devices. In the manufacture of conventional complementary metal oxide semiconductor (CMOS) devices, isolation regions, called field dielectric regions, e.g., field oxide regions, are formed in a semiconductor substrate of silicon dioxide by local oxidation of silicon (LOCOS) or by shallow trench isolation (STI). A conductive gate, such as polysilicon, is also formed on the substrate, with a gate oxide layer in between. A polysilicon layer is deposited on gate oxide. Thereafter, a patterned photoresist mask is formed on the polysilicon layer and the polysilicon layer—oxide layer is etched to form conductive gates with a gate oxide layer in between. Dielectric spacers are formed on sidewalls of the gate, and source/drain regions are formed on either side of the gate by implantation of impurities. Photolithography is conventionally employed to transform complex circuit diagrams into patterns which are defined on the wafer in a succession of exposure and processing steps to form a number of superimposed layers of insulator, conductor and semiconductor materials. Scaling devices to smaller geometries increases the density of bits/chip and also increases circuit speed. The minimum feature size, i.e., the minimum line-width or line-to-line separation that can be printed on the surface, controls the number of circuits that can be placed on the chip and directly impacts circuit speed. Accordingly, the evolution of integrated circuits is closely related to and limited by photolithographic capabilities. An optical photolithographic tool includes an ultraviolet (UV) light source, a photomask and an optical system. A wafer is covered with a photosensitive layer. The mask is flooded with UV light and the mask pattern is imaged onto the resist by the optical system. Photoresists are organic compounds whose solubility changes when exposed to light of a certain wavelength or x-rays. The exposed regions become either more soluble or less soluble in a developer solvent. There are, however, significant problems attendant upon the use of conventional methodology to form conductive gates with gate oxide layers in between on in a semiconductor substrate. For example, when a photoresist is formed on a highly textured surface such as polysilicon, and exposed to monochromatic radiation, undesirable standing waves are produced as a result of interference between the reflected wave and the incoming radiation wave. In particular, standing waves are caused when the light waves propagate through a photoresist layer down to the polysilicon layer, where they are reflected back up through the photoresist. These standing waves cause the light intensity to vary periodically in a direction normal to the photoresist, thereby creating variations in the development rate along the edges of the resist and degrading image resolution. These irregular rejections make it difficult to control critical dimensions (CDs) such as linewidth and spacing of the photoresist and have a corresponding negative impact on the CD control of the conductive gates and gate oxide layers. There are further disadvantages attendant upon the use of conventional methodologies. For example, distortions in the photoresist are further created during passage of reflected light through the highly reflective polysilicon layer which is typically used as a hardmask for etching. Specifically, normal fluctuations in the thickness of the polysilicon layer cause a wide range of varying reflectivity characteristics across the polysilicon layer, further adversely affecting the ability to maintain tight CD control of the photoresist pattern and the resulting conductive gates and gate oxide layers. Highly reflective substrates accentuate the standing wave effects, and thus one approach to addressing the problems associated with the high reflectivity of the silicon nitride layer has been to attempt to suppress such effects through the use of dyes and anti-reflective coatings below the photoresist layer. For example, an anti-reflective coating (ARC),.such as a polymer film, has been formed directly on the polysilicon layer. The ARC serves to absorb most of the radiation that penetrates the photoresist thereby reducing the negative effects stemming from the underlying reflective materials during photoresist patterning. Unfortunately, use of an ARC adds significant drawbacks with respect to process complexity. To utilize an organic or inorganic ARC, the process of manufacturing the semiconductor chip must include a process step for depositing the ARC material, and also a step for prebaking the ARC before spinning the photoresist. There exists a need for a cost effective, simplified processes enabling the formation of an ARC prevent the negative effects stemming from the underlying reflective materials during photoresist patterning. The present invention addresses and solves the problems attendant upon conventional multi-step, time-consuming and complicated processes for manufacturing semiconductor devices utilizing an ARC. DISCLOSURE OF THE INVENTION An advantage of the present invention is an efficient cost-effective method of manufacturing a semiconductor device with accurately formed conductive gates and gate oxide layers. Additional advantages of the present invention will be set forth in the description which follows, and in part, will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the present invention. The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims. According to the present invention, the foregoing and other advantages are achieved in part by a method of manufacturing a semiconductor device, which method comprises: forming an oxide-layer on a semiconductor substrate; forming a polysilicon layer on the oxide layer in a chamber; forming a silicon carbide coating on the polysilicon layer in the chamber; and forming a photoresist mask on the silicon carbide coating. Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein embodiments of the present invention are described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. BRIEF DESCRIPTION OF DRAWINGS FIGS. 1A-1E schematically illustrate sequential phases of a method in accordance with an embodiment of the present invention. DESCRIPTION OF THE INVENTION The present invention addresses and solves problems stemming from conventional methodologies of forming polysilicon gates and underlying gate oxides. Such problems include costly and time-consuming steps limited by materials which require different deposition systems and apparatus. The present invention constitutes an improvement over conventional practices in forming polysilicon gates and underlying gate oxides wherein a photoresist is formed on a highly reflective surface, such as polysilicon. The present invention enables the formation of polysilicon gates and underlying gate oxides with accurately controlled critical dimensions. In accordance with embodiments of the present invention, the semiconductor device can be formed by: forming an oxide layer on a semiconductor substrate; forming a polysilicon layer on the oxide layer in a chamber; forming a silicon carbide coating on the polysilicon layer in the chamber; and forming a photoresist mask on the antireflective coating. Embodiments of the present invention include forming the silicon carbide coating and the polysilicon layer in the same deposition chamber. Interconnect members formed in accordance with embodiments of the present invention can be, but are not limited to, interconnects formed by damascene technology. Given the present disclosure and the objectives of the present invention, the conditions during which the polysilicon layer and the silicon carbide antireflective layer are formed can be optimized in a particular situation. For example, the invention can be practiced by forming the polysilicon layer by introducing a silicon tetrahydride (SiH 4 ) gas in a chamber at a temperature greater than about 600° C., such as about 620° C. to about 650° C. Thereafter, silicon tetrahydride and toluene (C 7 H 8 ) are introduced into the chamber and a layer of silicon carbide is formed on the polysilicon layer in the same chamber. Given the stated objective, one having ordinary skill in the art can easily optimize the pressure, and gas flow as well as other process parameters for a given situation. It has been found suitable to maintain a gas flow of about 250 to about 350 SCCM, such as about 300 SCCM and a pressure of about 100 to about 300 mTorr, such as about 200 mTorr, during deposition of the polysilicon layer. Thus, an effective silicon carbide antireflective coating is formed by an elegantly simplified, cost-effective technique of forming both the polysilicon layer and the silicon carbide layer in the same chamber. An embodiment of the present invention is schematically illustrated in FIGS. 1A-1F. Adverting to FIG. 1A, a wafer 20 comprising a semiconductor substrate 25 , such as silicon, is provided. A barrier layer 30 , comprising an oxide, e.g. silicon dioxide, is deposited on the substrate, as by subjecting the wafer to an oxidizing ambient at elevated temperature. Embodiments of the present invention comprise forming the oxide layer to a thickness of about 100 Å to about 200 Å. With continued reference to FIG. 1A, a polysilicon layer 35 is deposited on the silicon dioxide layer 30 by placing the oxidized substrate in a chamber. The polysilicon layer 35 is formed by introducing a SiH 4 gas in a plasma deposition chamber at 300 SCCM at a pressure of about 200 mTorr and a temperature of about 620° C. Embodiments of the present invention comprise forming the polysilicon layer to a thickness of about 1200 Å to about 1600 Å. With reference to FIG. 1B, a silicon carbide layer 40 is formed on the polysilicon layer 35 , as by introducing SiH 4 and C 7 H 8 . The silicon carbide layer 40 can be formed to a thickness of about 100 Å to about 600 Å. The silicon carbide layer 40 has an extinction coefficient (k) greater than about 0.4, such as about 0.4 to about 0.6, thereby permitting tighter critical dimension control during patterning of the photoresist and tighter critical dimension control of the polysilicon gate and gate oxide, subsequently formed on the substrate 25 . The tighter critical dimension control is possible since the silicon carbide layer 40 absorbs a large percentage of the reflected light and thus prevents a non-uniform distribution of reflected light which may otherwise be incident on the photoresist during photolithography patterning. Referring to FIG. 1C, a photoresist mask 45 is formed on the silicon carbide layer 40 . Photoresist mask 45 can comprise any of a variety of conventional photoresist materials which are suitable to be patterned using photolithography. With continued reference to FIG. 1C, the photoresist mask 45 is patterned and holes 50 are formed in the photoresist mask 45 to provide an opening through which etching of the exposed silicon carbide layer 40 , polysilicon layer 35 and silicon dioxide layer 30 may take place. If critical dimensions, such as a line width and spacing, of the holes 50 in the photoresist mask 45 are not closely controlled, distortions occurring in forming the hole affect the dimensions of the polysilicon gate and gate oxide ultimately formed on the substrate 25 . As mentioned above, such distortions in patterning the photoresist mask 45 occur in conventional methodologies as a result of the high reflectivity of the polysilicon layer 35 and the thickness variations in the polysilicon layer and cause nonuniform photo-reflectivity. The silicon carbide layer 40 of the present invention substantially absorbs light reflected back through the polysilicon layer 35 , thereby reducing incident light on the photoresist mask 45 and preventing fluctuations which would otherwise occur in the critical dimensions of the holes 50 in the photoresist mask 45 . Adverting to FIG. 1D, conventional plasma etching of the silicon carbide layer 40 , the polysilicon layer 35 , and the silicon oxide layer 30 is conducted to strip them from the wafer. The plasma etching may occur in a single step or consecutive plasma etching steps. Referring to FIG. 1E, the photoresist mask 45 and optionally the underlying silicon carbide layer 40 are stripped from the wafer (not shown), utilizing conventional etching techniques. With continued reference to FIG. 1E, a conductive polysilicon gate 35 A remains on substrate 25 with a gate oxide layer 30 A in between. At this point, the wafer continues to the next stage in the overall manufacturing process. Subsequent conventional processing steps, though not illustrated, typically include; forming dielectric spacers on sidewalls of the gate; and forming source/drain regions on either side of the gate by implantation of impurities. In accordance with the present invention, metallization structures are formed in an elegantly simplified, efficient and cost-effective manner. Advantageously, the silicon carbide antireflective layer prevents the formation of standing waves and the negative effects stemming therefrom during photoresist patterning. The silicon carbide antireflective layer formed in accordance with the present invention is particularly advantageous in forming metallization interconnection patterns, particularly in various types of semiconductor devices having sub-micron features and high aspect ratios. In the previous description, numerous specific details are set forth, such as specific materials, structures, chemicals, processes, etc., to provide a better understanding of the present invention. However, the present invention can be practiced without resorting to the details specifically set forth. In other instances, well known processing and materials have not been described in detail in order not to unnecessarily obscure the present invention. Only the preferred embodiment of the present invention and but a few examples of its versatility are shown and described in the present disclosure. It is to be understood that the present invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.

Polysilicon gates are formed with greater accuracy and consistency by depositing a silicon carbide antireflective layer on the polysilicon layer before patterning. Embodiments also include depositing the polysilicon layer and the silicon carbide layer in the same tool.

CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority benefit of Taiwan application serial no. 91119089, filed Aug. 23, 2002. BACKGROUND OF THE INVENTION 1. Field of Invention The present invention relates to a high performance thermally enhanced package. More particularly, the present invention relates to a high performance thermally enhanced package with a cavity type heat sink therein and a method of fabricating the same. 2. Description of Related Art In this information conscious society, multi-media applications are developed at a tremendous pace. To complement this trend, integrated circuit packages inside electronic devices must match a set of corresponding demands for digital input, networking, local area connection and personalized usage. In other words, each electronic device must be highly integrated so that more powerful programs can be executed at a higher speed and yet each package has to occupy less space and cost less. Due to the miniaturization and densification of integrated circuit packages, most packages have an edge length only 1.2 times the encapsulated chip or a package area 1.25 times the chip area. Hence, each package is able to provide powerful functions within a very small area. Furthermore, each chip package can be easily mounted on a printed circuit board using standard surface mount technology (SMT) and common equipment. Therefore, chip packages are mostly welcomed by the industry. The most common types of chip packages include bump chip carrier (BCC) package, quad flat nonleaded (QFN) package and lead frame type package. FIG. 1 is a schematic cross-sectional view of a conventional bump chip carrier package. As shown in FIG. 1 , the bump chip carrier (BCC) package mainly comprises a silicon chip 110 , a layer of adhesive glue 104 , a plurality of bonding wires 106 , a plurality of terminals 108 and a plastic package body 110 . The chip 100 has a plurality of bonding pads 102 on its front surface and contains a layer of adhesive glue 104 on its back surface. The bonding pads 102 on the chip 100 are electrically connected to the terminals 108 through the bonding wires 106 . The plastic package body 110 encapsulates the chip 100 and the bonding wires 106 . In addition, the adhesive glue 104 at the back surface of the chip 100 is exposed outside the plastic body 110 . Through the terminals 108 , the chip 100 can communicate electrically with other electronic devices or a host board. However, to produce this type of package structure, an etching operation is needed to expose the adhesive glue 104 at the back of the chip 100 and shape the terminals 108 . Hence, the structure is a bit complicated to fabricate. FIG. 2 is a schematic cross-sectional view of a conventional quad flat nonleaded package. As shown in FIG. 2 , the quad flat nonleaded (QFN) package mainly comprises a chip 200 , a layer of adhesive glue 204 , a plurality of bonding wires 206 a , a plurality of bonding wires 206 b , a lead frame 208 and a plastic package body 210 . The lead frame 208 has a die pad 208 a and a plurality of leads 208 b . The chip 200 has a plurality of bonding pads 202 on the upper surface. The back surface of the chip 200 is attached to the die pad 208 a through the adhesive glue layer 204 . A portion of the bonding pads 202 on the upper surface of the chip 200 are electrically connected to the leads 208 b through respective bonding wires 206 b . Meanwhile, another portion of the bonding pads 202 on the upper surface of the chip 200 is electrically connected to the die pad 208 b (normally ground pads) through respective bonding wires 206 a . The plastic package body 210 encapsulates the chip 200 , the adhesive glue 204 and the bonding wires 206 a , 206 b such that one side of the die pad 208 a and the leads 208 b are exposed. The exposed surface of the die pad 208 a increases the heat dissipating capacity of the package while the exposed leads 208 b facilitate electrical connection with other devices or a host board. FIG. 3 is a schematic cross-sectional view of a conventional lead frame type of package. As shown in FIG. 3 , the lead frame type package mainly comprises a chip 300 , a layer of adhesive glue 304 , a plurality of bonding wires 306 , a lead frame 308 and a plastic package body 310 . The lead frame 308 has a die pad 308 a and a plurality of leads 308 b . The upper surface of the chip 300 has a plurality of bonding pads 302 thereon. The back surface of the chip 300 is attached to the die pad 308 a through the layer of adhesive glue 304 . The bonding pads 302 on the chip 300 are electrically connected to the leads 308 b through the bonding wires 306 . The plastic package body 310 encapsulates the chip 300 , the adhesive glue 304 , the bonding wires 306 , the die pad 308 a and a portion of the leads 308 b . Thus, the leads 308 b exposed outside the package body 310 can be electrically connected with other carriers. Heat generated by the package is channeled outside through the leads or an externally attached heat sink. Consequently, heat dissipation capacity for this type of package is usually low. All the aforementioned packages have a so-called wire-bonding chip design. In other words, the chip is electrically connected to the package through bonding wires. Bonding wires not only increase overall thickness of a package, but also increase overall circuit path compared with a conventional flip-chip packaging technique. Moreover, to package a wire-bonding chip into a flip-chip package, a wiring redistribution is required. After the redistribution process, overall circuit length will be increased so that a parasitic inductance problem may crop up. SUMMARY OF THE INVENTION Accordingly, one object of the present invention is to provide a thermally enhanced package and a method of fabricating the same that can reduce overall thickness of the package and provide a shorter overall circuit length. To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a thermally enhanced package. The thermally enhanced package mainly comprises a heat sink, a carrier, a layer of adhesive glue, a plurality of first electrical contacts, a silicon chip, a plurality of second electrical contacts and a plastic package body. The heat sink has a cavity. The carrier mounts over the heat sink. Since the heat sink has a cavity, a chip cavity for accommodating the silicon chip is formed between the carrier and the heat sink. The heat sink and the carrier are bonded together through the adhesive glue. The layer of adhesive glue has a plurality of openings that exposes the first electrical contacts. Through the first electrical contacts, the heat sink and a portion of the area on the carrier (such as ground leads and die pad) are electrically connected. The chip is enclosed inside the chip cavity above the carrier. The chip is electrically connected to the carrier through the second electrical contacts. The plastic package body fills up the chip cavity so that the chip and the cavity type carrier form a solid body. In the thermally enhanced package of this invention, the first electrical contacts within the adhesive glue are solder balls, for example. The second electrical contacts for connecting the chip and the carrier electrically are gold bumps or solder bumps. The gold bumps are, for example, the gold stud bumps formed by a wire bond machine or the gold stud bumps formed by electroplating. The carrier inside the thermally enhanced package is a lead frame, for example. The lead frame includes, for example, a die pad and a plurality of leads around the die pad. Each lead can be divided into an inner lead section and an outer lead section. In addition, the die pad and the outer leads are on a different plane (height), thereby providing a space for accommodating a chip. The heat sink of the thermally enhanced package is electrically connected to the die pad on the lead frame and a portion of the leads (such as the ground lead) through the first electrical contacts within the adhesive glue. Hence, the heat sink is actually connected to the ground. In the thermally enhanced package, the gap between the die pad of the lead frame and the active surface of the chip may include a layer of adhesive glue, for example. The carrier inside the thermally enhanced package may be a tape carrier, for example. The tape carrier comprises a tape, a die pad and a plurality of leads surrounding the die pad. The die pad and the leads are laid on the tape. Each lead is divided into an inner lead section and an outer lead section. In addition, the die pad and the outer leads are on a different plane (at different height levels) to produce a space for accommodating a chip. The heat sink of the thermally enhanced package is electrically connected to the die pad on the tape carrier and a portion of the leads (such as the ground leads) through the first electrical contacts within the adhesive glue. Hence, the heat sink is actually connected to the ground. The chip inside the thermally enhanced package may connect to the leads through bonding wires or directly through a flip chip design. Furthermore, adhesive glue may be used to fill the gap between the active surface of the chip and the die pad of the tape carrier. This invention also provides a method of fabricating a thermally enhanced package. First, a heat sink with a cavity thereon is provided. A layer of adhesive glue with a plurality of openings therein is formed over the heat sink. A first electrical contact is formed inside the openings. A carrier is attached to the heat sink through the adhesive glue. The carrier has a cavity that corresponds in position to the cavity on the heat sink so that a space for accommodating a chip is formed. A silicon chip having an active surface is provided. The active surface of the chip has a plurality of bonding pads thereon. A second electrical contact is formed on each bonding pads of the chip. The chip is next positioned inside the chip cavity followed by conducting a thermal compression process so that the chip and the carrier are electrically connected through the second electrical contacts. Finally, plastic material is injected into the chip cavity in a molding process. The carrier inside the thermally enhanced package can be a lead frame or a tape carrier and the chip can be a wire-bonding chip or a flip-chip, for example. The second electrical contacts can be any type of metallic bumps such as gold bumps or solder bumps. The gold bumps can be gold stud bumps formed by a wire bond machine or gold stud bumps formed by electroplating. Before positioning the chip inside the chip cavity in the aforementioned packaging process, adhesive glue may be applied to the active surface of the chip so that the active surface of the chip may connect electrically with the heat sink through the adhesive glue and the carrier. In addition, a dicing process may be conducted to produce individual units after plastic is injected to fill all the chip cavities in an array. It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings, FIG. 1 is a schematic cross-sectional view of a conventional bump chip carrier package; FIG. 2 is a schematic cross-sectional view of a conventional quad flat nonleaded package FIG. 3 is a schematic cross-sectional view of a conventional lead frame type of package; FIGS. 4A to 4F are schematic cross-sectional views showing the progression of steps for producing a thermally enhanced package according to a first embodiment of this invention; FIG. 5 is a cross-sectional view after the thermally enhanced package in FIG. 4F joins up with a printed circuit board; FIG. 6 is a top view of the lead frame inside the package according to the first embodiment of this invention; FIGS. 7A to 7F are schematic cross-sectional views showing the progression of steps for producing a thermally enhanced package according to a second embodiment of this invention; FIG. 8 is a cross-sectional view after the thermally enhanced package in FIG. 7F joins up with a printed circuit board; and FIGS. 9A to 9C are top views of the tape carrier used in a second embodiment of this invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. FIGS. 4A to 4F are schematic cross-sectional views showing the fabrication steps for producing a thermally enhanced package according to a first embodiment of this invention. As shown in FIG. 4A , a heat sink 400 having a cavity 402 thereon is provided. A layer of adhesive glue 404 is formed over the surface of the cavity 402 . The layer of adhesive glue 404 has a plurality of openings 404 a. As shown in FIG. 4B , first electrical contacts 406 a , 406 b are formed inside the openings 404 a of the adhesive glue layer 404 . The first electrical contacts 406 a , 406 b may protrude slightly above the adhesive glue layer 404 to facilitate subsequent electrical connection with other devices or a host hoard (not shown). As shown in FIG. 4C , a carrier such as a lead frame 500 is provided. The lead frame 500 has a die pad 502 and a plurality of leads 504 surrounding the die pad 502 . Each lead 504 can be further divided into an inner lead section 504 a and an outer lead section 504 b . A portion of the leads 504 in the lead frame 500 are ground leads. These ground leads 504 are electrically connected to the heat sink 400 through the first electrical contact 406 b and the die pad 502 on the lead frame 500 is electrically connected to the heat sink 400 through the first electrical contact 406 a. Since the heat sink 400 has a cavity 402 , a space 506 for accommodating a chip is produced on the lead frame, 500 in a location corresponding to the cavity 402 . The chip cavity 506 has a depth that depends on the type of chip to be enclosed inside the package. As shown in FIG. 4D , a semiconductor chip 408 is provided. The chip 408 can be an ordinary wire-bonding chip or a flip-chip. The chip 408 has an active surface 408 a with a plurality of bonding pads 410 thereon. A second electrical contact 412 is formed over each bonding pad 410 . The second electrical contact 412 are gold bumps or solder bumps, for example. The gold bumps can be, for example, gold stud bumps formed by wire bonding or gold stud bumps formed by electroplating. In addition, a layer of adhesive glue 414 may be applied over the active surface 408 a of the chip 408 . Thereafter, a thermal compression process may be carried out to form electrical connections between the chip 408 and the lead frame 500 . During thermal compression, the chip 408 is electrically connected to the inner leads 504 a of the lead frame 500 through the second electrical contacts 412 . Meanwhile, the active surface 408 a of the chip 408 also connects electrically with the heat sink 400 via the adhesive glue layer 414 , the die pad 502 and the first electrical contact 406 a. As shown in FIG. 4E , an encapsulation process is carried out. In the molding process, packaging plastic 416 is injected to fill the entire chip cavity 506 . Through the packaging plastic, the chip 408 and the lead frame 500 form a solid body. As shown in FIG. 4F , a dicing process may be carried out so that each individual package within an array is separated and excess material surrounding a package is removed. FIG. 5 is a cross-sectional view after the thermally enhanced package in FIG. 4F joins up with a printed circuit board. As shown in FIG. 5 , the package (in FIG. 4F ) mounts on a printed circuit board 700 that serves as its carrier. The printed circuit board 700 is electrically connected to the outer leads 504 b of the lead frame 500 so that the chip 408 forms an assembly with the printed circuit board 700 . In this embodiment, the printed circuit board 700 and the outer leads 504 b of the lead frame 500 are electrically connected through an electrical medium such as third electrical contacts 602 . The third electrical contacts 602 may be fabricated with solder paste, for example. In addition, a heat conductive pad 600 may be inserted in the gap between the printed circuit board 700 and the chip 408 so that heat can be channeled away from the back of the chip 408 via the heat conductive pad 600 to the printed circuit board 700 . FIG. 6 is a top view of the lead frame inside the package according to the first embodiment of this invention. As shown in FIG. 6 , each lead 504 in the lead frame 500 can be divided into an inner lead section 504 a and an outer lead section 504 b . A portion of the junction between the inner leads 504 a a and the die pad 502 may employ a lead break design. The lead break design facilitates the detachment of inner leads 504 a from the die pad 502 . However, the lead break design will be removed in a subsequent operation to prevent the inner leads 504 a and the die pad 502 from short-circuiting. FIGS. 7A to 7F are schematic cross-sectional views showing the fabrication steps for producing a thermally enhanced package according to a second embodiment of this invention. As shown in FIG. 7A , a heat sink 400 having a cavity 402 thereon is provided. A layer of adhesive glue 404 is formed over the surface of the cavity 402 . The layer of adhesive glue 404 has a plurality of openings 404 a. As shown in FIG. 7B , first electrical contacts 406 a , 406 b are formed inside the openings 404 a of the adhesive glue layer 404 . The first electrical contacts 406 a , 406 b may protrude slightly above the adhesive glue layer 404 to facilitate subsequent electrical connection with other devices or a host board (not shown). As shown in FIG. 7C , a carrier such as a tape carrier 800 is provided. The tape carrier comprises a tape 802 , a die pad 804 and a plurality of leads 806 surrounding the die pad 804 . Each lead 806 may be further divided into an inner lead section 806 a and an outer lead section 806 b . A portion of the leads 806 in the tape carrier 800 are ground leads. These ground leads 806 are electrically connected to the heat sink 400 through the first electrical contact 406 b and the die pad 804 on the tape carrier 800 is electrically connected to the heat sink 400 through the first electrical contact 406 a. Since the heat sink 400 has a cavity 402 , a hollow space 808 for accommodating a chip is produced on the tape carrier 800 in a location corresponding to the cavity 402 . The chip cavity 808 has a depth that depends on the type of chip to be enclosed inside the package. As shown in FIG. 7D , a semiconductor chip 408 is provided. The chip 408 can be an ordinary wire-bonding chip or a flip-chip. The chip 408 has an active surface 408 a with a plurality of bonding pads 410 thereon. A second electrical contact 412 is formed over each bonding pad 410 . The second electrical contact 412 are gold bumps or solder bumps, for example. The gold bumps can be, for example, gold stud bumps formed by wire bonding or gold stud bumps formed by electroplating. In addition, a layer of adhesive glue 414 may be applied over the active surface 408 a of the chip 408 . Thereafter, a thermal compression process may be carried out to form electrical connections between the chip 408 and the tape carrier 800 . During thermal compression, the chip 408 is electrically connected to the inner leads 806 a of the tape carrier 800 through the second electrical contacts 412 . Meanwhile, the active surface 408 a of the chip 408 also connects electrically with the heat sink 400 via the adhesive glue layer 414 , the die pad 804 and the first electrical contact 406 a. As shown in FIG. 7E , an encapsulation process is carried out. In the process, packaging plastic 416 is injected to fill the entire chip cavity 808 . Through the packaging plastic, the chip 408 and the tape carrier 800 form a solid body. As shown in FIG. 7F , a dicing process may be carried out so that an individual package within an array is separated and excess material surrounding a package is removed. FIG. 8 is a cross-sectional view after the thermally enhanced package in FIG. 7F joins up with a printed circuit board. As shown in FIG. 8 , the package (in FIG. 4F ) mounts on a printed circuit board 700 that serves as its carrier. The printed circuit board 700 is electrically connected to the outer leads 806 b of the tape carrier 800 so that the chip 408 forms an assembly with the printed circuit board 700 . In this embodiment, the printed circuit board 700 and the outer leads 806 b of the tape carrier 800 are electrically connected through electrical medium such as third electrical contacts 602 . The third electrical contacts 602 may be formed with solder paste, for example. In addition, a heat conductive pad 600 may be inserted in the gap between the printed circuit board 700 and the chip 408 so that heat can be channeled away from the back side of the chip 408 via the heat conductive pad 600 to the printed circuit board 700 . FIGS. 9A to 9C are top views of the tape carrier used in a second embodiment of this invention. As shown in FIGS. 9A , 9 B and 9 C, each lead 806 can be divided into an inner lead section 806 a and an outer lead section 806 b . A portion of the junction between the inner leads 806 a and the die pad 804 may employ a lead break design. The lead break design facilitates the detachment of inner leads 806 a from the die pad 804 . However, the lead break design will be removed in a subsequent operation to prevent the inner leads 806 a and the die pad 804 from short-circuiting. As shown in FIG. 9A , the position of the opening on the tape carrier 800 corresponds to the die pad 804 so that the die pad 804 is directly grounded. In FIGS. 9B and 9C , the die pad 804 and the inner leads 806 a are both supported by the underlying tape 802 . Furthermore, the tape 802 underneath the die pad 804 has a plurality of open holes 810 . Through these open holes 810 , the die pad 804 is also grounded. Moreover, in FIG. 9C , the end of each outer lead 806 b includes a connecting pad 812 . In summary, the thermally enhanced package and associated method of fabrication have at least the following advantages: 1. Using either a lead frame or a tape carrier, overall area and thickness of the package can be reduced. 2. The heat sink in the package is connected to ground through electrical contacts and hence the heat sink can serve as an electromagnetic interference shield. 3. There is no need to use bonding wires to serve as an electrical connection medium. Hence, overall package size can be reduced. 4. The package permits not only the use of flip chips, but also the direct electrical connection between a wiring chip and a lead frame. Since there is no need for redistribution, overall circuit length is reduced and hence problems caused by parasitic induction are minimized. In addition, time for developing and cost for producing a new type of chip is shortened. 5. When flip-chip technique is combined with thermal compression to fabricate the package, yield and reliability of the package is improved. The shortening of average circuit path provides superior linear operation characteristics. 6. Soldering material is not required to join the tape carrier and the chip. Hence, bump pitch can be further reduced to about 45 μm. 7. The tape carrier can be designed into a variety of shapes for accommodating different types of chips. It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

A high performance thermally enhanced package and method of fabricating the same is provided. A chip (a wire bond chip or a flip chip) and a carrier (lead frame or tape carrier) are bonded together using flip-chip technology and thermal compression. The chip and the carrier are encapsulated using a molding compound. The package has a smaller overall size and the capacity to withstand electromagnetic interference.

CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit of International Application PCT/EP2004/051008, filed Jun. 3, 2004, which claims priority from German Application 103 31 646.9, filed Jul. 12, 2003. BACKGROUND OF THE INVENTION The invention relates to a method for teaching a knowledge-based database for automatic defect classification. In semiconductor manufacturing, wafers or masks are processed sequentially in a number of process steps during the manufacturing process. With increasing integration density, the demands of the quality of the structures formed on the wafers increase. In order to check the quality of the structures formed and to be able to find possible defects, the demand for quality, precision, and reproducibility of the components and process steps used with the wafer is critical. This means that during production of a wafer with a number of process steps, a reliable and early recognition of defects is especially important. In this process, it is necessary to classify the defects that occur in order to thus achieve a fast processing and testing of the wafers. In earlier versions of “Automatic Defect Classification” (ADC), it was necessary to proceed with a manual classification of the defects on a wafer or on a mask. The teaching of a knowledge base was thus extremely time consuming. SUMMARY OF THE INVENTION The object of this invention is to provide a method with which a simple and fast possibility is offered for creating all the data and files (knowledge base, auto alignment, focus setup) necessary for an “ADC run.” This object is achieved by a method of learning a knowledge-based database for automatic defect classification wherein a review data file is selected, and parameters and data are input by a user on one page of a learning mode, where the parameters and the data are known to the user. Additionally, an alignment procedure and a procedure for adjusting light intensity are used. Optimal light intensity is automatically adjusted by approaching a few defects and if necessary regulating the optimal illumination. Detection is checked using a few examples wherein the optimization of the detection parameters is carried out using pictures. Respective defects are detected and a descriptor is assigned to the respective defect by automatically approaching all defects of a wafer or wafers. Descriptors of the defect are then analyzed and automatically grouped. It is especially advantageous that Leica ADC HP offers a simple and fast option for creating data and files (knowledge base, auto alignment, focus setup) for an ADC run. To do this, in part specified data and files are used. Since a manual classification of the defects on a wafer is no longer necessary, as in earlier ADC versions, the time needed to create a new ADC protocol for teaching a knowledge base can be reduced by up to 50%. Additionally, in many cases the quality of the knowledge base improves because of the “pregrouping function” that is included, which in turn has a direct influence on the precision of the ADC run. ADC HP is described as an independent “learn mode”. In individual steps, the user must specify, confirm and if necessary change the required data. The individual steps are shown as separate pages in the Leica ADC HP dialog. The user prompts for the individual pages are in the so-called wizard style, i.e., using <Back> and <Next> buttons. In contrast to the previous learning mode, the new learning mode has the advantage that it is uncomplicated and requires a reduced number of steps that have to be carried out by the user in the proper sequence. In the previous learning mode, preclassified defects were required. All the new learning mode needs is one or more wafers with as many unclassified defects as possible. Since during a few of the steps an interaction with the Viscon interface is necessary, the Leica ADC HP dialog is not displayed modally, but top-most. The dialog can automatically be hidden or the user can make it hidden or visible again. The input of parameters and data includes the selection of the elements present on the semiconductor substrate, whereby it is possible for memory circuits, logic circuits, and a blank wafer without resist or with resist to exist as elements. The parameters or data of the layers on the wafer include the data of a polymer layer, of an oxide layer, of a contact or of a metal layer. The user selects the illumination type, at least one lens and a focus type. For the illumination type, bright field, UV or DUV can be selected. The default setting is bright field, and the default for the lens is 100× magnification. A manual two-point alignment is carried out, whereby a first point is aligned manually by approaching a table. During the learning of the first point, data is automatically stored for the auto alignment file. Each alignment point is learned with three different magnifications of the lens. The adjustment of the optimal intensity of illumination is carried out by random selection of a specific number of defects. Then the selected defects are approached and a picture is taken of each defect. A starting value for the brightness of illumination and the adjustment of the illumination is achieved using a histogram evaluation of the pictures. Defects that are no larger than 25% of the video image width and height are used to adjust the optimal intensity of the illumination. Twenty defects will be used to adjust the intensity of illumination. Of the defects on the wafer that are approached, pictures are taken and stored temporarily until pictures are taken of all defects. After all the pictures have been taken, they are shown on the display as thumbnails. A few thumbnails are rejected if the thumbnails exceed a threshold value for the focus. The analysis and automatic grouping of the descriptors of the defects divides the thumbnails of the defects that have been produced into groups. On the display, the first nine examples of a selected group of defects in a thumbnail representation are shown. BRIEF DESCRIPTION OF THE DRAWINGS In the following, the invention will be explained in more detail using embodiment examples that are shown schematically in the figures. The same reference numbers in the individual figures refer to the same elements. The following are shown in detail: FIG. 1 shows a schematic structure of a wafer inspection device as an overview in which the method according to the invention is implemented; FIG. 2 shows the ADC HP toolbar button with which the user calls the function for automatic defect recognition; FIG. 3 shows the ADC HP call of the “ADC” menu; FIG. 4 shows a “Leica ADC HP Control Desk” window that clearly summarizes, in one window, the ADC tasks that are already partially available in earlier ADC versions; FIG. 5 shows a page of a learning mode that the user calls up and in this process an input file opens, i.e., specifies a review data file; FIG. 6 shows a page of the learning mode that the user calls and thus assigns a name for a “recipe file”; FIG. 7 shows a page of the learning mode by which the user specifies the ADC knowledge base data; FIG. 8 shows a page of the learning mode by which the user carries out the teaching and an automatic alignment; FIG. 9 shows a page of the learning mode by which the user carries out an automatic light adjustment; FIG. 10 shows a page of the learning mode by which the user achieves an optimization of the adjustment of the detection parameters; FIG. 11 shows a representation of the thumbnails on the screen; FIG. 12 shows a representation of a message box; FIG. 13 shows a representation of a change sensitivity dialog; FIG. 14 shows a representation of a window that gives the user a warning message; FIG. 15 shows a representation of an information window for acceptance of the new detection threshold; FIG. 16 shows a page of the learning mode by which the user carries out an automatic generation of a knowledge base; FIG. 17 shows a representation of the “defect code mapping” dialog; FIG. 18 shows a representation of an information dialog; FIG. 19 shows a representation of a dialog for starting the “ADC run”; FIG. 20 shows a representation of a finish dialog; FIG. 21 shows a representation of a report dialog; and FIG. 22 shows a representation of the printed Easy ADC Report. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic structure of a wafer inspection device 1 as an overview, in which the method according to the invention is implemented. On a base frame 2 , scanning table 4 is integrated as a placement table for wafer 8 . Scanning table 4 can be driven in an X-coordinate direction and a Y-coordinate direction. Wafer 8 to be tested is placed or hooked on scanning table 4 . An observation device that is preferably equipped with a microscope lens 7 is connected to base frame 2 by way of a carrier unit 9 . Microscope lens 7 makes possible the enlarged observation of wafer 8 . Several microscope lenses 7 can be provided on a revolving unit (not shown) so that observation with different enlargements is possible. The structures of wafer 8 that are observed when they are enlarged can be observed directly using eyepiece 5 or by way of a display 11 that is connected to a CCD camera 13 . Additionally, electronic unit 15 is provided with which a system automation can be achieved. In particular, electronic unit 15 is used to control scanning table 14 , for reading out camera 13 and for controlling display 11 . Wafer holder 16 is usually designed in such a way that it can hold wafer 8 to be tested so that it is fixed during the testing period. Scanning table 14 is designed so that it can be driven in each perpendicular X-coordinate direction and one Y-coordinate direction. In this way, each point to be observed on wafer 8 can be brought under optical axis 7 a of microscope lens 7 ( FIG. 1 ). FIG. 2 shows ADC HP toolbar button 20 , with which the user calls the function for automatic defect recognition. The ADC HP dialog is called using “ADC” HP toolbar button 20 or using main toolbar 19 of Viscon application 21 in “ADC” menu or in the context menu of the “ADC” dialog (see FIG. 3 ). Every user (starting from the “operator” user level) has access to this menu entry. Since ADC HP is a separate option, the menu entry is only visible if ADC HP is also installed. This option is protected, as before, using a registry entry that is generated by the installation program when this option is selected. If a program is already loaded in Viscon, the menu entry will be shown deactivated. FIG. 4 shows “Leica ADC HP Control Desk” window 25 . It combines the ADC tasks, some of which were already available in earlier ADC versions, clearly in a window and is used as the starting basis to start individual modules 26 , 27 , 28 , and 29 . In detail, this includes: “Learn recipe”: learning and creation of a new ADC recipe and a knowledge base with subsequent ADC run (run recipe), “Edit recipe”: for processing an available knowledge base, “Expand recipe”: for expanding an available knowledge base and “Run recipe”: to start an ADC run. One button is provided for each of the individual modules. In the current embodiment, this includes “learn recipe”—button 26 , “edit recipe”—button 27 , “expand recipe”—button 28 and “run recipe”—button 29 . When individual buttons 26 , 27 , 28 , 29 are actuated, the individual tasks are executed. Those tasks that were already present in the earlier ADC version will only be discussed briefly here. “Edit recipe”: After pressing is button 27 , the user has to select an available knowledge base file. This is started by the external application “KB Wizard” and the contents of the file are displayed. The data can be processed there and the knowledge base as a whole can be tested. “Expand recipe”: With button 28 , the user selects an available knowledge base file and a review data file. During the subsequent ADC run, new data are collected and temporarily stored in the background. Once the run is completed, the temporary data and the knowledge base (KB) file used will be loaded by the “KB Wizard” application and displayed. The user can now take the new data selectively over into the knowledge base. “Run recipe”: By selection of button 29 , a review data file and an ADC recipe will be selected and an ADC run will be started. All defects selected by the user will be detected automatically and classified using the knowledge base file noted in the ADC recipe. The results will be written again at the end as a review data file. The task connected with the actuation of “learn recipe”—button 26 will be described in detail in the following. The ADC HP learning mode is displayed as a non-modal dialog. The user must input the necessary data and/or select files in eight successive steps, i.e. on eight pages. The last page only represents the result of the ADC HP learning process. To do this, the user can use <Back> and <Next> buttons 30 , 31 (wizard style), as long as the current status allows it, to go to the previous or to the next step (see FIG. 5 ). In general, it is true that the display of the individual pages is not user-level-dependent. The exceptions are additional user interface elements that are only visible to the development user level. These are now visible during the development phase and will be removed in the release version and be generally invisible for all user levels. FIG. 5 shows page 33 of the learning mode that the user calls up and thereby opens an input file 34 , i.e., specifies a review data file. Page 33 is designated with “open input file.” On page 33 , the data file is displayed (without path). Using file open button 35 , the directories are displayed for the user for data input. If an input file has been determined, it is temporarily opened, but the Viscon sequencer is not started. The file “EasyADCLearn.vsl” is used as the script file, hard coded. The necessary data for LotId (lot identification), WaferId (wafer identification), StepId (step identification) and SetupId (setup identification) of the first wafer are read out from the open file. Then the file is closed again. Any standard settings (e.g. Auto Start) are not affected by the process and/or will be put back to the original status. The user can cancel the procedure with a cancel button 39 . FIG. 6 shows page 38 of the learning mode that the user calls up and thereby assigns a name for a recipe file. Page 33 is designated with “recipe file.” Actuating back button 30 is not allowed in page 38 . Actuation of next button 31 is allowed if a valid input file 37 has been selected. The user can cancel the ADC HP learn mode with cancel button 39 . The Leica ADC HP recipe file is displayed in edit box 40 . The previously read name components are summarized according to specification, and the resulting file name (with the extension .“vsl”) is displayed. The name components are separated by a “_” symbol (underscore). Invalid letters in the resulting file name will be removed and hyphens will be replaced with underscores. The user also has the option of changing the specified name (completely or partially) as desired. The file “EasyADCRun.vsl” is used as a template for the resulting recipe file (sequence control file during an ADC run) (hard coded). Page 38 contains several checkboxes 41 , 42 , 43 and 44 . Checkboxes 41 , 42 , 43 and 44 are used to determine the name components. In this case, LotID, StepID and SetupId are used as defaults. The resulting file name (without the extension .“vsl”) is also used as a default for other files (auto alignment, focus setup file, etc.). The data file of the results “result data file” is always written with the same name as the input file and the same format type and in the standard result directory. Back button 30 is permitted and next button 31 is permitted if at least one name component has been selected. Cancel button 39 is permitted. FIG. 7 is shows page 50 of the learning mode by which the user specifies data for the ADC knowledge base. Page 50 is designated as “ADC basic data.” In selection column 51 with the designation “structure type,” the user can choose between “memory” and “logic.” An additional selection or a blank, unstructured wafer “bare wafer” is also possible. To determine the ADC run mode (repetitive or random mode) and/or auto alignment modes (normal auto alignment or bare wafer alignment), the procedure is according to the selection. The default setting is set to “logic.” In selection column 52 , which has designation layer type, the user can select whether one or more layers will be applied to the wafer. Also of interest is which layers will be applied to the wafer. Without resist is “w/o resist,” with resist is “with resist” (see FIG. 7 ). The resists, or also other layers, are applied on wafer 8 or the semiconductor substrate. The default setting is “w/o resist.” In other setting options, the user can select the layer type. A polymer layer is designated with “poly,” an oxide layer with “oxide,” a contact with “contact” or a metal layer with “metal.” The sequence of application of the different layers can also be selected. For example, an oxide layer (oxide) is applied before the polymer layer, this is designated with “before poly.” The selection of the layer type metal allows the user the choice between a single metal layer (metal 1 ), a double metal layer (metal 2 ) and an n-fold metal layer (n-metal). The determination of whether a main layer or a subordinate layer is involved, is used to determine the random mode and the focus type. The default settings for the layers are “poly,” for “oxide”: before poly and for “metal”: metal 1 . Oxide and metal sub-layer radio boxes are only activated if “oxide” or “metal” has previously been selected. Otherwise they are shown deactivated. In selection column 53 , the user can select the “illumination mode.” The radio boxes with the designation BF for bright field, UV for ultraviolet and DUV for deep UV are available to the user. In a list box 54 , the lenses that are available are displayed to the user, whereby only the lenses that fit the selected ADC type are displayed. The default setting is bright field “BF,” and a lens with 100× or lower magnification is suggested. The following table (Table 1) shows the resulting focus setting using the selected data: Layer/ADC type Focus type Offset value for TV focus Poly TV focus 400 Poly resist TV focus 0 Oxide before poly Laser — Oxide before poly resist TV focus 0 Oxide after poly TV focus 2000 Oxide after poly resist TV focus 2000 Contact Laser — Contact resist Laser — Metal 1 TV focus 1500 Metal 1 resist TV focus 0 Metal 2 TV focus 1800 Metal 2 resist TV focus 0 n-Metal TV focus 2500 n-Metal resist TV focus 0 For TV focus, the default values of the “TV Focus Flexible 2 ” mode are used. Back button 30 , next button 31 and cancel button 39 are permitted in this window. If next button 31 is pressed, the ADC HP dialog becomes invisible. A copy of the “EasyADCLearn” files is created and specific actions are adapted (auto alignment) and data (grab setup). The same changes are made for the named copy of the “EasyADCRun” file (the later ADC run recipe). The input file is loaded with the adapted script file, and the Viscon NT sequencer is started. The file is automatically processed up to wafer selection. The standard wafer selection dialog is used and displayed. As a default, all available wafers are selected (default setting in easy ADC script file). FIG. 8 is a page 60 of the learning mode, by which the user carriers out the teaching and an automatic, or at least semi-automatic, alignment, page 60 is designated as “alignment procedure.” After actuation of the wafer selection by the user, the first wafer is loaded and the file is processed up to auto alignment. Depending on the setting of the layers present on the wafer, the learning mode of the corresponding auto alignment will be started (semi-auto or later bare wafer alignment). The user can carry out a manual two-point alignment whereby only the very first point is aligned manually (driving of the table using joystick or by mouse double click in the live video image) and confirmed. During the teaching of the first point, data is automatically stored for the auto alignment file. Each alignment point is taught with three different lens magnifications, whereby the highest magnification lens is specified by the selection on page 50 (ADC basic data). The second point is already taught and aligned automatically using the stored data of the first point. The selected ADC lens is always specified by the software. This lens must be used since it will be needed for the later light adjustment (method used: alignment point). If the learned structure of the first input point is not found on the second alignment point, the second point will be “offset” toward the center point of the wafer and the structure will be searched again. The second point is “offset” by a maximum of six dies before the alignment aborts with a defect. In this case, an information window will be displayed to the user that says that the alignment has been aborted and the wafer is discharged. After the end of the alignment, the Viscon sequencer is paused (incorporated pause action (without message box display) in the easy ADC script file), the ADC HP dialog becomes visible again and displays the next page. Next button 31 is not permitted if alignment is carried out and/or has been aborted due to a defect. Next button 31 is permitted if the alignment was successful. Cancel button 39 is permitted and cancels the entire ADC HP learning mode. FIG. 9 is page 70 of the learning mode by which the user carries out an automatic light adjustment. This page is designated as “light adjustment.” After pressing a “perform automatic light adjustment” button 71 , a specific number of points (defects from the data file) will be selected randomly. If size information is available, only defects will be selected that are greater than 25% of the video image width and height. These defects are approached and pictures are taken. A “lamp brightness” start value is determined using histogram evaluation and adjusted at the microscope. This means that the brightness will be regulated down so that no defect image is “overwritten.” To do this, all available color channels will be tested and adjusted in an appropriate way. Then an automatic light adjustment is carried out. If it is successful, the data obtained will be stored in the knowledge base file. As a default, 20 points (defects) are used for the “starting value” determination and the “alignment” method of the light adjustment is used. Page 70 contains Statusbox 72 (“progress control box”) and Infobox 73 “read only edit box.” During the automatic light adjustment, the progress is displayed in Statusbox 72 . A status text is displayed in Infobox 73 whether this is successful or unsuccessful. Back button 30 is not permitted when the light adjustment is being carried out. Back button 30 is permitted if the light adjustment is rejected. The wafer is discharged, and page 50 “ADC basic data” is displayed. Next button 31 is permitted if the light adjustment was successful. The cancel button is permitted if light adjustment has been carried out and in this process all open files were closed and deleted. FIG. 10 is a page 80 of the learning mode, by which the user achieves an optimization of the setting of the detection parameters. Page 80 is designated as “optimize ADC detection.” The process is started using a button 81 , which is designated as “start optimization.” The optimization function will ensure that the standard values for focus adjustment and detection parameters function on the selected wafer. If this is not the case, the user has the option here again of changing the specified standard values. After button 81 is pressed, the Viscon sequencer is started, defects are selected, approached and pictures are taken. The text on button 81 then changes into “stop optimization.” The progress of the picture taking is displayed in a status box 82 . The user can then cancel the procedure by pressing it again. If all the necessary pictures have been taken, they will be displayed in another dialog in an additional representation on the screen as thumbnails. Ten defects (hard coded) are used for optimization. The number can be changed using a registry entry and/or development user level. Back button 30 is not permitted if the detection optimization is being carried out. Next button 31 is not permitted if the detection optimization is carried out. Cancel button 39 is not permitted if the detection optimization is carried out. By pressing <Start Optimization> button 81 , the Viscon sequencer is started again, the button text changes to “stop optimization” and a specified number of defects of the current wafer is selected. The defects are approached and in this process a special ADC action is initiated. This action takes the pictures, detects the defects using an ADC routine that is already developed and stores the pictures temporarily until pictures of all the defects have been taken. The progress of this procedure is displayed by means of the status box. During picture taking, the user can cancel the procedure by repeatedly pressing the button. FIG. 11 shows a representation of several thumbnails 91 1 , 91 2 , 91 3 , . . . , 91 n on display 11 . If all pictures have been taken, the ADC HP dialog is switched to invisible and the pictures are displayed in a thumbnail dialog 90 (complete picture display on the screen). The Viscon sequencer pauses at this time. Thumbnail dialog 90 is basically divided into first area 91 , second area 92 , third area 93 and a fourth area 94 . First area 91 comprises a horizontal list in which thumbnails 91 1 , 91 2 , 91 3 , . . . , 91 n are represented with detection marking and defect ID (defect identification). The currently selected picture is shown in second area 92 with a maximum resolution of 640×480 pixels. If available, the reference pictures are also shown, reduced, in third area 93 . The current picture selection can be changed using a mouse click, cursor keys and/or browse buttons 95 under the defect picture. The defect marking can be switched off and back on again using <Hide Defect Detection> button 96 . Browse buttons 95 are used for selection and display of the next or the previous defect picture. <Hide Defect Detection> button 96 is designed as a toggle button, and in this way the detection marking can be made visible or invisible. Focus difference—defect/reference button 97 makes it possible to display a message box 86 (see FIG. 12 ). During operation, the selected defect picture (and available reference pictures) will be thrown away, i.e., deleted from the display. If an internal threshold value (default: 30%) of the unsatisfactory pictures thrown away (bad focus pictures) is exceeded, the focus values are changed (i.e., change from laser to TV focus or change of the TV focus offset in 500 nm steps). The defects are then approached again and data recorded. To do this, thumbnail dialog 90 is closed and the ADC HP dialog will be displayed again during the scan procedure. Wrong defect detection button 86 makes it possible for the detection threshold for the selected picture to be determined again. To do this, a new dialog 80 is displayed (see FIG. 10 ). Refresh button 87 makes it possible for the average value of the threshold of all pictures in the list to be determined, and all detections will be recalculated with this new average value. The list will then be set up again. Pictures with “autothreshold” (−1) are not used to determine the average value. Default button 88 makes it possible for all the changes in the detection parameters of all pictures to be reversed. The list is set up again with the original values. The dialog is closed with an apply button 89 , the average value of the threshold is calculated and taken over as a global detection parameter. Pictures with “autothreshold” (−1) are not included for determining the average value. The optimized dialog is closed, the ADC HP dialog is switched so that it is visible again and the new overall detection threshold is entered in the knowledge base. Cancel button 39 closes the optimize dialog, and the ADC HP dialog becomes visible again. All changes are rejected. FIG. 13 is an illustration of a dialog 100 for “change sensitivity.” Dialog 100 is used to determine the optimum setting for the detection threshold of the selected defect picture. Defect picture 101 is displayed centrally with the associated detection threshold in dialog 100 . If indirect automatic detection threshold has been used due to prior adjustments (on page 50 “ADC Basic Data”), a value of 50% is assumed. The sensitivity of the detection can be reduced or increased using two buttons 102 . Defect picture 101 shown in the center shows the defect recognition with the currently selected sensitivity. The value is shown under defect picture 101 . Reduced picture 103 is shown on the left next to defect picture 101 and shows the change in detection with reduced sensitivity. Also, reduced picture 103 is shown at the right next to defect picture 101 and shows the change of the detection with increased sensitivity. By clicking with the mouse on one of the reduced pictures and/or by pressing on the buttons 102 lying under them, the current sensitivity is changed to this value and the picture is now shown in the center. The changes on the left and right will then be recalculated. Hide defect detection button 105 is designed as a toggle button. In this way, the detection marking is switched to visible or invisible. Slider 106 with the designation “sensitivity step size” is used to change the magnitude of changes of sensitivity during actuation of button 102 . Delete image button 107 is used to reject a defect for further evaluation. The defect is removed from the list of the optimization dialog. This dialog is closed, and the user goes to the previous dialog. FIG. 14 is a representation of a window 110 that gives the user a warning message. If an internal threshold (default: 30%) of the “wrong detection” pictures rejected is exceeded, new defects can be selected (automatically), approached and data recorded. Apply button 107 starts the application. FIG. 15 is a representation of information window 110 for acceptance of the new detection threshold. The information window informs the user that by acceptance of the new detection threshold the detection of all the other pictures will also change. The new value will be applied to all other pictures by pressing on <Refresh> button 87 in optimize dialog 90 . By operating <Yes> button 111 , the detection threshold of the center image display is taken over and the user goes back to dialog 100 . By operating cancel button 39 change in dialog 100 , all changes made are rejected and the user goes back to optimization dialog 90 (see FIG. 11 ). FIG. 16 shows page 120 of the learning mode, by which the user carries out an automatic generation of a knowledge base. With start collecting data button 121 , all the necessary data for all defects of all selected wafers are accepted and recorded. The status is displayed to the user in Statusbox 122 and Infobox 123 . Infobox 123 displays the defects “yet to be processed” from the total number (e.g. “267 of 750”). Operating back button 30 is not allowed when the data acceptance procedure is running. Operating next button 31 is also not allowed if the data recording procedure is running. Operation of cancel button 39 is not allowed when the data recording procedure is running. If the actuation of cancel button 39 is allowed, all open files will be closed and deleted. The sequence is as follows: The Viscon sequencer is started again and all defects of the input file are selected. In a first step, defects on the wafer or wafers are approached, pictures are taken, descriptors generated and stored in the ADC result data on the defect. The pictures of the defects will be stored with the following settings: “Write to Archive File” “All Images” “Image Compression”: yes “Leica-ImageStore”: no In a second step, the Viscon sequencer pauses on the basket level (before storing the output file). In a third step, the generation of the groups from the collection of descriptors occurs (“pregrouping”). In a fourth step, the pregrouping attempts to create a maximum of 20 groups. Groups with less than two examples are rejected. The resulting groups are copied temporarily to the knowledge base, whereby the defect code and defect description of each group are “numbered” for the first time (1, 2, 3, etc., or EasyClass 1 , EasyClass 2 , EasyClass 3 , etc.) In a fifth step, dialog 130 is displayed for dividing the defects i.e. “defect code mapping” (see FIG. 17 ). “Defect code mapping dialog” 130 is essentially represented by first window 131 , a second window 132 , third window 133 and a fourth window 134 . In first window 131 , a binder icon is shown for each group generated in the fourth step. Window 132 displays the pictures of the first nine examples of the selected group in a thumbnail representation. Window 133 displays the actual defect code table. By selecting a defect code and pressing <Map> button 135 , this code is assigned to the selected classes. The icon of this class changes in that it gets a green hook 136 and the corresponding defect code text is displayed. This “mapping” can also be executed by a double click in the defect code table. When <Delete Group> button 137 is pressed, the currently displayed group is marked for deletion. The corresponding binder icon gets a red cross 138 . When pressed, toggle button 139 designated with “optimize image display” makes it possible for a section around the defect marking in original size of the example pictures to be shown. If the defect marking in an example picture is too large, the display does not change. By pressing toggle button 139 on again, you go to the reduced full picture display. Operation of apply button 129 is allowed if all defect groups have been handled, i.e., mapped or marked for deletion. In a sixth step, there is an attempt to reduce the number of individual examples per mapped group (groups marked as for deletion will not be used and rejected). This is necessary so that specific groups with a lot of defects do not dominate the knowledge base and defects can preferably be assigned to this class. The result is taken over into the knowledge base, and the user comes to the ADC learning mode during operation of cancel button 39 on display 11 of information dialog 140 shown in FIG. 18 . After operating <Yes> button 141 , the “mapping” in the entire ADC learning mode will be canceled. FIG. 19 shows a representation of a dialog 150 for starting an ADC run. With a start ADC run button 151 , after button 151 is pressed there is a classification of all defects of the selected wafers “offline” (i.e., without approaching them again). The classification is carried out with the current ADC knowledge base. Dialog 150 includes a Statusbox 152 and Infobox 153 . The display of the defects yet to be classified of the total number is displayed in Statusbox 153 (e.g., “123 of 750”). Operation of back button 30 is not permitted if Offline ADC is running. Operation of next button 31 is not permitted if Offline ADC is running. Also the operation of cancel button 39 is not allowed if Offline ADC is running. If the operation of cancel button 39 is allowed, all open files will be closed and deleted. If next button 31 was pressed, the sequencer is started again. The result data file is written and the sequencer ends automatically, whereby all files that are still open are closed. FIG. 20 shows a representation of a dialog 160 which is the finish screen. An Infobox 161 is provided for an output file. Infobox 161 is used to display the stored data files. Only the file name is displayed. The Easy ADC VSL file is also displayed in Read Only Editbox 162 . The display of the generated “ADC run” file appears in Infobox 162 . Only the file name is displayed. The complete path is displayed in a tool tip. The number of “total defects” is displayed in Infobox 163 . The total number of all defects can be read Infobox 163 . The “defects detected” will be displayed in Infobox 164 . The “redetection” of the defects in percent will also be displayed in Infobox 166 . The display of the defects detected with ADC is shown absolutely and as a percentage. LED 149 displays in color whether the percentage lies above the predefined value. If the value lies above the predefined value, LED 149 is green, otherwise LED 149 is red. The number of classified defects is displayed in Read Infobox 165 . The percentage of classified defects “classifiability” is also shown in Infobox 167 . The display of the defects classified with ADC is shown absolutely and as a percentage. LED 148 shows in color whether the percentage lies over a predefined value. Green means that the percentage lies over the predefined value. If the value lies below that, the display is red. By operating a report button 147 , a report dialog 170 is displayed ( FIG. 21 ). Report dialog 170 is user-dependent. Another report is displayed only starting at the ‘engineer’ user level. The operation of finish button 146 will end the process. FIG. 21 shows report dialog 170 with the expanded display of data in an Infobox 171 . The following data are output: file information: (P) output file name (+path), recipe information: (P), ADC HP recipe file name (+path), knowledge base file name (+path), auto alignment file name (+path), focus type “LASER” or “VIDEO” with grab setup file names (+path), knowledge base information (A) (P), lens used, contrast method used, focus type, aperture used, light intensity used, statistical information (P), number of wafers, total number of defects, number of classified defects, number of ADC classes, defects per class (in matrix form), number of detected defects, absolute/percent, number of classified defects, absolute/percent, number of classifications per ADC defect class (P), performance information: (A) (P), accuracy, purity, confusion matrix (A) (P) and a defect list (A). A sorted table contains the following data per date record: the slot number, the event number, the manual classification, the ADC classification, the ADC classification with confidence value and the ADC classification with confidence value. In this case, only the first 300 entries are output. (A) means that these data are visible only in the expanded report. (P) means that the data can be printed out. Report dialog 170 is provided with print button 171 . A preview of the ADC HP report is displayed on display 11 . The printout can be printed out using a standard printer. The printout is in landscape format since in portrait format the paths are usually not completely displayed or printed out. FIG. 22 is a representation of a printed Easy ADC Report 180 . When save button 173 is operated (see FIG. 21 ), the ADC HP report can be stored as a test file (extension TXT).

The invention relates to a method of learning a knowledge-based database used in automatic defect classification. According to this method, the user is spared a series of entries as the system carries out an automatic learn mode, which requires a reduced number of user entries.

[0001] This application is a national phase application of PCT/KR2006/002872, and claims priority from Korean application (KR) 20-2005-0022608 (Aug. 2, 2005) for inventor KIM, Ki Ryong. TECHNICAL FIELD [0002] The present invention relates to a road traffic-control signboard assembly, and more particularly, to a road traffic-control signboard assembly having an automatic returns function. BACKGROUND ART [0003] Road traffic-control signboards are essential elements in running of vehicles. Since road traffic-control signboards should be optimally recognized at drivers' visual fields, they are usually fixed at right angle to vertical supports which are built vertically at the margin of roads. For example, a conventional road traffic-control signboard assembly will be described below with reference to part of FIG. 1 . [0004] In the case of the conventional road traffic-control signboard assembly, a road traffic-control signboard 40 is simply fixed to the road traffic-control signboard stay bar 1 which is extended again over the road, using a U-bolt and nut. Therefore, assemblers' manpower can be reduced but the durability thereof is very poor. The following problems are caused. That is, as stated above, the conventional road traffic-control signboard assembly assembles the road traffic-control signboard 40 with the traffic signboard stay bar 1 using the U-bolt and nut. Thus, if strong force is applied to the conventional road traffic-control signboard assembly, because typhoon blows, an initial position of the road traffic-control signboard 40 is changed to thus make the front surface of the road traffic-control signboard 40 turn up to the sky or down to the road, or make it suspended at a slope. As a result, the road traffic-control signboard 40 loses its function and causes a failure in safety running of vehicles. [0005] In the meantime, if impact is applied to the conventional road traffic-control signboard assembly, due to the excessively loaded freight in freight vehicles or the top portion of special-purpose motor vehicles such as cranes or heavy equipment, the obverse of the road traffic-control signboard 40 is slanted heading toward the road or is damaged. Finally, the same problems as those described above are caused. Hereupon, local government road facilities that receive accident or damage reports ride bucket vehicles and go to sites immediately, in order to straighten the road traffic-control signboard whose initial position has been changed again or replace it by a new one. For this reason, roads are blocked to thus delay a smooth road condition and cause a big economical loss and damage nationalistically. On the other hand, when typhoon blows or after typhoon passes a lot of road traffic-control signboards are out of position over the downtown whole area. In this case, big problems such as confusion, discomfort, and traffic jams are caused. [0006] Moreover, repair works of long hours cause various kinds of big problems. Hereupon, to solve the above-described problems, this inventor filed a Utility-model application No. 20-2003-0040773 on Dec. 26, 2003 with the Korean Intellectual Property Office entitled “Horizontal support structure for making traffic-control signboards rotate” which has been registered as a Utility-model registration No. 20-0349900-0000 on Apr. 29, 2004. By the way, the above-described registered conventional art greatly changes the structure of the existing road traffic-control signboard stay bar 1 . In principle, the existing road traffic-control signboard stay bar 1 does not cause any problem but is complicated in the structural viewpoint since a coil spring should be is mounted so as to be concentric with the road traffic-control signboard stay bar 1 . As a result, in the case of the conventional art, it is not so easy to manufacture the road traffic-control signboard 40 and assemble it in the road traffic-control signboard stay bar 1 to thus cause the manufacturing cost to greatly rise up and the maintenance to be difficult and to additionally cause an unsafe problem since the weight of the road traffic-control signboard assembly is heavy. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT [0007] To solve the above problems, it is an object of the present invention to provide a road traffic-control signboard assembly having a generally advanced automatic return function using structure of an existing road traffic-control signboard stay bar 1 as it is, which is preeminently improved in view of the function, economy, assembly, maintenance, weight, etc., in comparison with those of the conventional art. To accomplish the above object of the present invention, according to an aspect of the present invention, there is provided a road traffic-control signboard assembly comprising: a tubular elastic body having an insertion groove so as to be inserted into a road traffic-control signboard stay bar which is connected with a vertical support at right angle and a hole into which a rotation preventing screw can be inserted at right angle; a semicircular upper clamp which is assembled to enclose the tubular elastic body at the upper portion of the tubular elastic body, including a tightener having bolt holes through which a respective bolt is penetratively fixed for fixing a below-described lower clamp, in which the tightener is extended from the semicircular upper clamp, a hole into which a rotation preventive screw can be inserted at right angle, and a hasp which can hang a below-described tension spring on the upper portion of the semicircular upper clamp; a flat lower clamp which is hinged with the upper clamp, having bolt holes through which a respective bolt is penetratively fixed for fixing the upper clamp; a support plate which is assembled in a hinged manner with the lower clamp and the upper clamp, to support a road traffic-control signboard; a hinge pin which assembles the upper clamp, the lower clamp and the support plate all in a hinged manner; a reinforcement plate at the upper portion which a hanger for hanging the tension spring, in front of which the road traffic-control signboard is fixed, and with which the support plate is assembled with bolts and nuts; a tension spring which is assembled between the hasp of the upper clamp and the hanger of the reinforcement plate, which supports the road traffic-control signboard so as to return vertically even if the road traffic-control signboard moves; and bolts and nuts which rigidly tighten the upper clamp and the lower clamp. Preferably, a plate-shaped or rod-shaped stopper is additionally fixed on the upper portion of the upper clamp, so that the erect road traffic-control signboard is not inclined toward the upper clamp Preferably, the material of the tubular elastic body is selected among rubber, sponge, and urethane. BRIEF DESCRIPTION OF THE DRAWINGS [0008] The above and other objects and advantages of the present invention will become more apparent by describing the preferred embodiments thereof in detail with reference to the accompanying drawings in which: [0009] FIG. 1 is a perspective view showing the whole structure of a road traffic-control signboard assembly according to the present invention; and [0010] FIG. 2 is a sectional view showing a-state of use of the road traffic-control signboard assembly according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION [0011] Herein below, a road traffic-control signboard assembly according to a preferred embodiment of the present invention will be described. The same reference numeral presented in the drawings show the same element. [0012] First, the road traffic-control signboard assembly according to the present invention does not change structure of an existing road traffic-control signboard stay bar 1 but uses it as it is. In this point of view, the present invention differs greatly from the conventional art. The present invention has many inventive characteristics in which its structure is very simpler and its durability is more excellent than those of the conventional art. [0013] That is, referring to FIGS. 1 and 2 in the present invention, a tubular elastic body 30 made of rubber, sponge, or urethane can be simply inserted into a proper position of a road traffic-control signboard stay bar 1 (hereinafter, referred to as a stay bar 1 ). As shown in FIGS. 1 and 2 , an insertion groove 31 that can be inserted into the outer surface of the stay bar 1 . The lower portion of the tubular elastic body 30 is opened and thus the insertion groove 31 can be extended by hands seizing the tubular elastic body 30 . Then, the tubular elastic body 30 can be simply inserted into the stay bar 1 . Finally, the tubular elastic body 30 is closely fixed to the stay bar 1 as shown in FIG. 2 . In the meantime, the tubular elastic body 30 is preferably fabricated in various forms in size, according to change in diameter of the stay bar 1 , but since the tubular elastic body 30 has an elasticity naturally, there is no reason to produce the tubular elastic body 30 in various sizes certainly because there is no problem to use it even if diameter of the stay bar 1 is a little big or small. Further, since the standard and diameter of the stay bar 1 are substantially the same, only one basic type of the tubular elastic body 30 can be used without causing any problems. [0014] As described above, after the tubular elastic body 30 is inserted into the stay bar 1 , a hole is formed on the stay bar 11 through a hole 32 using a hand drill. The diameter of the hole does not cause any hindrance in intensity of the stay bar 1 . In this case, if the end portion of a rotation preventive screw 16 may be inserted into the hole, the diameter of the hole can be acceptable. Here, the tubular elastic body 30 can be assembled with the stay bar 1 after a hole has been formed on the stay bar 1 . [0015] Next, after a semicircle upper clamp 10 is positioned at the upper portion of the tubular elastic body 30 , the rotation preventive screw 16 is assembled through the hole 32 of the tubular elastic body 30 and a hole 13 of the upper clamp 10 . Accordingly, as shown in FIG. 2 , the tubular elastic body 30 and the upper clamp 10 can be kept in their positions on the stay bar 1 . [0016] Then, a flat lower clamp 20 which is assembled with the upper clamp 10 by a hinge pin 15 in a hinged manner, is made to contact the bottom of the stay bar 1 and to be fixed to the stay bar 1 using bolts 50 and nuts 51 , as shown in FIG. 2 . [0017] Then, a support plate 70 is assembled in a hinged way with the upper clamp 10 and the lower clamp 20 by the hinge pin 15 . Then, a reinforcement plate 60 to which a road traffic-control signboard 40 is fixed, is located in front of the support plate 60 , and is assembled by bolts 41 and nuts 42 . That is, the support plate 70 , the reinforcement plate 60 and the road traffic-control signboard 40 are integrally formed. [0018] As shown in FIGS. 1 and 2 , a tension spring 80 is hung between a hasp 14 of the upper clamp 10 and a hanger 61 of the reinforcement plate 60 , and assembled. As shown in FIG. 2 , a plate-shaped or rod-shaped stopper 90 is additionally fixed on the upper portion of the upper clamp 10 , so that the erect road traffic-control signboard 40 is not inclined toward the upper clamp 10 . [0019] As described above, the rotation preventive screw 16 can be replaced by an ordinary pin, bolt, or annular rod. Here, when the tubular elastic body 30 and the upper clamp 10 are assembled with the stay bar 1 after the annular rod is soldered and fixed to the stay bar 1 beforehand, the annular rod can pass through and protrude from the respective holes 32 and 13 . However, in this case, it is naturally expected that it will be difficult to work. Also, the tubular elastic body 30 of the present invention is cut at its lower portion thereof, and thus the insertion groove 31 is opened. Accordingly, the lower clamp 20 contacts justly the bottom of the stay bar 1 , and thus the road traffic-control signboard 40 can be turned by as a big angle as an arrow trajectory of FIG. 2 . As a result, in the case that impact due to collision of a freight vehicle is applied to the lower portion of the road traffic-control signboard 40 , the road traffic-control signboard 40 is smoothly escaped from the impact lest the central portion of the road traffic-control signboard 40 should not be damaged. As being the case, a perfectly pipe-shaped tubular elastic body can be used. In the meantime, as described above, any commercial changes belong to the technical scope of the present invention. [0020] It is natural that two sets of road traffic-control signboard assemblies according to the present invention be used for one road traffic-control signboard. If the road traffic-control signboard becomes large in size, it is natural that several road traffic-control signboard assemblies be assembled with one stay bar in use. [0021] As described above, the road traffic-control signboard assembly according to the present invention is used in the state of FIG. 2 . Even if wind force or other impact is applied in front of the road traffic-control signboard 40 in the FIG. 2 state, the road traffic-control signboard 40 is pushed to the left-side direction of the arrow and is turned over within various angle ranges. Thereafter, if the wind force that is, birr or other impact disappeared, the road traffic-control signboard 40 returns to the original position by the pulling force of the tension spring 80 . Here, a reason why the road traffic-control signboard 40 has been pushed backward by the birr or impact which has been applied to the road traffic-control signboard 40 is because the stopper 90 is fixed to the upper clamp 10 , and thus the upper portion of the road traffic-control signboard 40 is not pushed backward based on the hinge pin 15 . [0022] In the meantime, even in the case that strong wind blows from the left side of the road traffic-control signboard 40 to the right side thereof, in the FIG. 2 state, the road traffic-control signboard 40 is not turned to the left side of the road traffic-control signboard 40 but is turned only to the right side thereof. This is also because the road traffic-control signboard 40 cannot be turned toward the upper clamp 10 by the stopper 90 . Here, a coil spring is assembled with the hinge pin 1 , to thus keep the road traffic-control signboard 40 in its position. However, it is not always necessary to assemble the coil spring with the hinge pin 1 . [0023] As described above, the present invention provides a road traffic-control signboard assembly having an automatic return function even if impact is applied to a road traffic-control signboard. The conventional art changes the structure of the stay bar 1 , but the present invention does not change the existing stay bar 1 in use. This feature of using the existing stay bar without changing the structure of the stay bar is inventive in itself. Further, the road traffic-control signboard assembly can be simply assembled with and disassembled from the stay bar 1 , and the structure of the road traffic-control signboard assembly is very simple. Accordingly, it is easy to fabricate the road traffic-control signboard assembly. Moreover, the present invention is more excellent in its maintenance, more inexpensive in its manufacturing unit cost, and lighter in its weight to thus enable a very easy installation and maintenance work, than those of the conventional art. As a result, the present invention has an economic efficiency having preeminently improved characteristics. [0024] Further, a semi-permanent use is possible since the present invention has an excellent durability from the structural characteristic and the frequent breakdown has hardly occurred. In particular, the tubular elastic body 30 does not need to be fabricated according to diameter of the stay bar 1 , even if the diameter of the stay bar 1 alters a little, and the road traffic-control signboard assembly according to the present invention can be flexibly used, to thereby provide an effect of doing a big contribution in enhancing the whole economic efficiency, convenience, workability. [0025] As described above, the present invention has been described with respect to particularly preferred embodiments. However, the present invention is not limited to the above embodiments, and it is possible for one who has an ordinary skill in the art to make various modifications and variations, without departing off the spirit of the present invention. Thus, the protective scope of the present invention is not defined within the detailed description thereof but is defined by the claims to be described later and the technical spirit of the present invention. INDUSTRIAL APPLICABILITY [0026] As described above, the present invention provides a road traffic-control signboard assembly which can be used for a traffic-control signboard.

Provided is a road traffic-control signboard assembly with which a road traffic-control signboard can be assembled while being linked with a vertical support at right angle. The road traffic-control signboard assembly is fitted with and fixed to a road traffic-control signboard stay bar and has a structure of being returned to an original position even if impact by typhoon or collision of vehicles is applied to the road traffic-control signboard. Thus, the road traffic-control signboard assembly prevents a phenomenon that an initial fixed position of the road traffic-control signboard is changed because of impact by typhoon or collision of vehicles which is applied to the road traffic-control signboard, to thereby lose the function of the road traffic-control signboard.

BACKGROUND OF THE INVENTION The present invention pertains to an apparatus for threading metal into a heating device and for removing scales that form and flake from the metal during heating. More particularly, the present invention relates to an induction heater having a continuous belt that threads metal strip into the induction heater and removes metal scales that form and flake from the metal during heating. Induction heating is used to heat metal pieces such as, strip, bars, slugs, billets, tubes, slabs, plate and the like, by passing the metal pieces through a pathway wherein the metal is heated by an induction coil. The purpose of the induction heating may be to permit hot rolling, annealing, hardening, brazing or soldering two parts together, or treating metal in some other manner. One particular application of induction heaters involves their use in conjunction with the continuous casting of metal strip. Because metal strip is thin and wide having a large surface area, it cools quickly upon exiting a continuous caster. Therefore, an induction heater, such as a transverse flux coil, may be utilized to reheat the strip metal so that it can be properly rolled. A transverse flux coil is desirable because of its ability to operate in a relatively small space, and heat thin metal strip in the above Curie temperature range. When induction heaters are utilized in conjunction with continuous casters, at least one problem arises. After the metal strip exits a continuous caster, it is soft and limp because it is hot. As a result, it is difficult to thread the metal strip horizontally through an induction heater such as a transverse flux coil. To date, there is no device that the applicant is aware of that effectively threads limp or soft metal through an induction heater. Thus, a need exists to provide such an apparatus. An additional problem associated with induction heaters when used in any application involves the formation of metal scales during heating. All heating of metals causes at least some scale to form on the surfaces of the part undergoing treatment when the heating processes are carried out in an oxygen-containing environment such as air. Ambient air, containing oxygen reacts with the metal at elevated temperatures causing scales to form on the surface of the work-piece. As the induction heater continues to increase the temperature of the metal, the scales flake off or fall from the work-piece. The flaking off of scales into the induction heating device is an undesirable result since it often causes failure of the induction coils. One of the most prevalent causes of failure resulting from flaking of metal scales involves short circuiting. The metal scales drop from the work-piece and accumulate between the work-piece and the inductor. As the scale builds up within the housing of the induction heater, they begin to span the space between the work-piece and the inductor. Thus, a complete circuit is formed therebetween. Since the work-piece is generally supported by metal support components of the induction heating apparatus which are grounded, a short circuit is completed to ground through the inductor and work-piece. In an effort to alleviate some of the adverse effects accompanying a short circuit of the foregoing character, prior designs have provided a sensor for detecting a short circuit before significant damage is done. For example, in response to detection of a short circuit, a control circuit may be actuated to disconnect the inductor from its power supply. This causes the inductor to de-energize so that the necessary steps can be taken to remedy the short circuit condition. In addition, a control circuit may be rendered operable to preclude the work-piece from entering the induction heater. While short circuit detection devices of the foregoing character advantageously serve to protect the inductor and/or work-piece from significant damage, a considerable amount of production time is lost in shutting down the apparatus and performing the necessary maintenance operations to clear the inductor area of the metal scales causing the short. Furthermore, once the inductor area is cleaned, it is only a matter of time before scale accumulation will again cause a short to ground requiring shut-down and additional maintenance. Another attempt to solve the problems associated with the formation of scales during induction heating is disclosed in U.S. Pat. No. 3,745,293 (Seyfried). Seyfried teaches an induction heating apparatus having an auxiliary circuit operable to cause burning of metal scales disposed between the inductor and work-piece. Such burning is achieved by establishing a low voltage circuit through the inductor and work-piece and the metal scales therebetween. By maintaining the burn-out circuit at low voltage, the metal chips are burned away and the inductor is not energized in such a manner that the work-piece is heated prematurely. Although Seyfried was an advance in the art, the device has several shortcomings. First, the device suffers from a significant decrease in production time. In operation, Seyfried allows the scales to accumulate until a shorting would occur. Then, it shuts off the primary circuit and activates the secondary circuit. The secondary circuit or auxiliary circuit burns and eliminates the metal scales. By shutting down the primary circuit and waiting for the secondary circuit to burn off the metal scales, significant production time is lost. An additional drawback of Seyfried is the complexity and therefore increased cost of the device. It requires an additional complicated circuit. If a problem arises with the auxiliary circuit, it will likely be a difficult problem to fix. Accordingly, there is a need in the industry to provide for an improved apparatus capable of effectively threading soft or limp metal through an induction heater that is also capable of removing scales produced during heating. The present invention contemplates a new and improved apparatus having such advantages. BRIEF SUMMARY OF THE INVENTION In accordance with the present invention there is provided a threading and metal scale removing device comprising a heating apparatus for heating a work-piece. The heating apparatus has an inlet through which the work-piece is threaded and an outlet through which the work-piece exits. A plurality of rollers are operatively associated with the heating apparatus. At least one rotatable belt is mounted on the plurality of rollers. The belt is adapted to thread the work-piece through the heating apparatus and remove metal scales that form and flake off the work-piece during heating. A motor is operatively connected to the rollers for driving the rollers thereby causing the belt to rotate through the heating apparatus. In accordance with another aspect of the present invention, there is provided a metal scale removing device comprising a heating apparatus for heating a work-piece. The heating apparatus has and inlet through which the work-piece is fed and an outlet through which the work-piece exits. A plurality of rollers are operatively associated with the heating apparatus. A rotatable belt is mounted on the plurality of rollers and is adapted to catch metal scales that have fallen from the work-piece and transport the metal scales away from the heating apparatus. One advantage of the present invention is the provision of a new threading device for induction heaters. Another advantage of the present invention is the provision of a new and improved scale removing device for induction heaters. Yet another advantage of the present invention is the provision of a belt rotatably disposed within an induction heater capable of effectively threading soft or limp metal material through the induction heater. Still another advantage of the present invention is the provision of a belt rotatably disposed within an induction heater having the ability to remove metal scales that form and flake off metal materials during heating. Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the detailed description of the preferred embodiment. BRIEF DESCRIPTION OF THE DRAWINGS The invention may take physical form in certain parts and arrangements of parts, preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof, and wherein: FIG. 1 is a schematic view of a threading and scale removal device in accordance with the teachings of the present invention; and FIG. 2 is perspective view of the present invention operating solely as a scale removing device. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings wherein the showings are for purposes of illustrating the preferred embodiments of the invention only and not for purposes of limiting the same, FIG. 1 shows a threading and scale removing device used in conjunction with an induction heater. However, it will be appreciated that the present invention may be used in conjunction with any conventional heating apparatus requiring threading of soft metal and/or scale removal. With reference to FIG. 1, an induction heater A includes an inlet 12 through which a work-piece 10 , such as a metal strip of steel or aluminum, is received. The work-piece 10 is threaded through the entry 12 and undergoes treatment before exiting through an outlet 14 located at the other side of the induction heater A. Upper and lower induction coils 18 , 20 are disposed within the induction heater for applying heat to the work-piece. Frames 11 and 13 support the coils 18 , 20 . In the illustrated embodiment, the work-piece 10 is soft and limp as it approaches the inlet 12 of the induction heater, having already been heated by a continuous caster (not shown) or other heating device. As such, a first tension roll set 26 is provided for receiving the work-piece and applying tension to the metal strip before it enters the induction heating assembly. Additionally, a first table roll 28 is disposed adjacent the first tension roll for receiving the strip metal from the tension roll and supporting the limp work-piece as it approaches the induction heater. Since the strip metal 10 is still limp when it reaches the inlet 12 of the induction heater A, a threading means is provided to effectively transfer the workpiece through the induction heater. The threading means preferably includes a belt 30 adapted to rotate through the induction heater. The belt is formed from a non-metallic material that is not affected by varying the magnetic field applied by the induction heater. The belt is mounted on a series of water cooled rollers 32 , 34 , 36 , 38 disposed around the periphery of the lower half of the induction heater A. The rollers are preferably located at the four corners of the substantially rectangular lower half of the heater. An optional tension roller 40 is disposed between the two lower rollers 36 , 38 and floats in the bracket 39 for desired tensioning of the belt. A belt motor 50 drives the rollers causing the belt to rotate in a clock-wise manner. As best seen in FIG. 1, the limp work-piece falls onto the belt 30 upon entering the induction heater. Accordingly, the belt supports the work-piece as it travels through the heating device. In a preferred embodiment, the belt and the work-piece travel at the same rate so as to prevent abrasion between the belt and the strip-metal. Upon exiting the outlet 14 of the induction heater A, a second table roll 60 bites or grabs the work-piece 10 . The strip travels over the second table roll and through a second tension roll 62 . At this point, the tension applied by the second tension roll lifts the work-piece from the belt so that all slack in the strip metal is eliminated. As a result, the work-piece is fully extended along the dotted line of FIG. 1 and is no longer in contact with the belt 30 . While passing through the induction heater, the belt is exposed to extremely high temperatures emitted from the work-piece. Therefore, the belt is preferably made from a material capable of withstanding elevated temperatures, such as a ceramic material. Additionally, it is beneficial to cool the belt and minimize its exposure to these elevated temperatures. One way to accomplish this is by increasing the speed of the belt after the belt has taken a fully extended position. Once the belt is fully extended and no longer in contact with the work-piece, the rate of travel of the strip is not critical. Thus, the belt speed can be increased thereby minimizing the amount of time the belt is in the induction heater. An air spray device 64 or the water cooled rollers are used to help cool the belt. In operation, a work-piece 10 travels through a first tension roll 26 onto a the first table roll 28 . The work-piece proceeds toward the inlet 12 of the induction heater A where the belt 30 threads the work-piece through the induction heater. Upon exiting the heater at the outlet 14 , the second table roll 60 bites or grabs the work-piece and transfers it to the second tension roll 62 . The tension applied by the second tension roll and the table rolls causes the work-piece to become fully extended and separated from the belt 30 . The work-piece continues to travel through the induction heater in this manner until threading is again required. However, the belt can also support the end of the strip as it exits the coil. Another significant function of the belt in the present invention is its ability to remove scales that form and flake from the work-piece as it passes through the induction heater A. In almost all induction heaters where significant amounts of heat are added to a work-piece, oxygen reacts with the work-piece to form metal oxide scales on the surface of the work-piece. As the induction heater continues to heat the metal material, the scales begin to flake off the surface of the work-piece. In a conventional induction heater, the scales fall into the interior of the heating device causing a number of problems, including short-circuiting. However, the belt 30 in the present invention prevents such problems. After the belt has threaded the work-piece 10 through the heating apparatus, it functions as a metal scale removing device. More particularly, the belt rotates beneath the work-piece thereby catching the scales that fall from the work-piece and transporting them away from the heating device. As such, the scales are prevented from falling into the interior of the heating device and causing the many problems already discussed. In operation, a work-piece 10 such as strip metal is threaded through the inlet 12 of the induction heater. As the temperature increases, metal scales begin to flake from the surface of the work-piece. The belt 30 , which moves in the same direction as the work-piece, catches the metal scales and carries them away from the induction heater. Once the belt reaches the outlet 14 of the induction heater, it makes a downward 90° turn. Inertia causes the metal scales to be separated from the belt into a chute 70 positioned adjacent the induction heater. The scales fall through the chute onto a conveyer 80 which transports and ultimately disposes of the scales. It must be appreciated that the metal scale removing aspect of the present invention may be incorporated into any type of induction heater or heating device, even when the threading aspect is not necessary. For example, FIG. 2 illustrates the metal scale removing device of the present invention in conjunction with an induction heating coil B for treating slabs. In this illustrated embodiment, a work-piece 10 , such as a slab, is fed through the induction heating coil B. Since slabs are not limp or flimsy, the threading aspect of the invention is immaterial and is not utilized in this environment. As such, the invention acts only as a scale removing device and the table rolls and tension rolls of FIG. 1 are not required. However, at least one table roll 28 may be used to support and guide the work-piece as is shown in FIG. 2 . After the work-piece has entered the heating apparatus and scales begin to fall from the slab, a belt 30 , driven by rollers 32 , 34 and moving in the same direction as the slab 10 , catches the scales and transports them away from the coil. The metal scales fall through a chute 70 into a conveyor 80 for ultimate disposal (See FIG. 1 ). As FIG. 2 illustrates, not all induction heaters need a threading device. In fact, most work-pieces are not soft and limp and therefore do not need a special threading device. Therefore, the present invention may be used solely as a metal scale removing device for any heating apparatus without having to incorporate the threading aspect of the invention. When only the scale removing aspect is desired, the table rolls and tension rolls of FIG. 1 are eliminated. However, when threading is required, the table rolls and tension rolls are provided and the belt functions as both the threading device and the scale removal device. The invention has been described with reference to the preferred embodiments. Obviously modifications and alterations will occur to others upon a reading and understanding of this specification. For example, a second belt 90 could be disposed on the top half of the induction heater as shown in FIG. 1 to be used either in conjunction with the first belt 30 or in place of the first belt. In addition, the length of the belt may be varied in order to use a lower belt temperature rating. The present invention is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or equivalents thereof

A threading and scale removing device is disclosed which includes a heating apparatus having an inlet and an outlet. A work-piece is fed through the inlet and exits through the outlet. A plurality of rollers are operatively associated with the heating apparatus. A belt is mounted on the plurality of rollers and is adapted to rotate through the heating apparatus. As the belt rotates, it functions to thread the work-piece through the heating apparatus. Once the work-piece has been threaded through the heating apparatus, the belt functions to catch and remove metal scales that flake from the work-piece during heating. A motor is operatively connected to the plurality of rollers for driving the rollers and allowing the belt to rotate through the heating apparatus.

BACKGROUND OF THE INVENTION There is a growing need for low cost, lightweight, low profile, readily mass-producible, high aperture-efficiency antennas of useful bandwidth in a variety of mass market applications. The desirable characteristics of low cost, lightweight, low profile and mass producibility are provided in general by printed circuit antennas. The simplest forms of printed circuit antennas are "microstrip" antennas wherein flat conductive elements are spaced from a single essentially continuous ground element by a single dielectric sheet of uniform thickness. Such antennas are easily constructed from one layer of double clad circuit board material. Microstrip antennas with increased aperture efficiency and increased bandwidth would be very desirable. One type of microstrip antenna utilizes radiating monopoles, each of which produce an omnidirectional radiation pattern in the plane of the antenna surface. Such an antenna is disclosed in U.S. Pat. No. 3,377,592 wherein short sections of otherwise uniform microstrip transmission lines are displaced in one direction from the centerline of the transmission line at intervals of one wavelength. All the outside corners of any one transmission line acquire the same charge simultaneously to produce monopoles and a radiation pattern that has a principal lobe that is tangential to the surface of the antenna. A second type of microstrip antenna utilizes thin conductive resonant dipole radiator elements, each of which produces a radiation pattern having a principal lobe broadside (perpendicular) to the antenna surface. Each of such dipole radiator elements has two orthogonal coordinates that respectively define E and H planes of electromagnetic radiation for that radiator element. The E coordinate dimension of each radiator element is approximately one-half the dielectric wavelength λo√ε r μ r , where λo is the free space wavelength, ε r is the relative dielectric constant and μ r is the relative permeability of the dielectric sheet. The dielectric sheet is generally λo/100√ε r μ r to λo/10√ε r μ r Thick with the preferred range being λo/75√ε r μ r to λo/15√ε r μ r . In an antenna it is desirable that such radiator elements radiate in a predetermined amplitude and phase relationship with respect to each other. The amplitude relationship may be a uniform illumination wherein all radiator elements contribute equally to a radiation pattern. Alternatively, the amplitude relationship may be a tapered distribution. The radiator elements should radiate in phase with respect to each other to create a broadside beam. An off-broadside beam may be created by having a progressive phase shift along rows or columns of radiator elements. One class of microstrip antennas utilizing resonant dipole radiator elements employs capacitative coupling of energy to radiator elements. Such an antenna is disclosed in U.S. Pat. No. 3,016,536 wherein rectangular resonant dipole radiator elements are distributed on a broad surface. The E coordinate dimension of each radiator element is approximately λo/2√ε r μ r . The H coordinate dimension of each radiator element is considerably less than the E coordinate dimension. Such radiator elements form collinear arrays in the E coordinate direction with capacitative coupling between radiator elements for energy transfer. The center dipole of each collinear array consists of a pair of quarter wavelength radiator elements that form a balanced center-fed dipole. Several center-fed dipoles and their respective collinear arrays are driven from a balanced line to provide a two dimensional planar array. Such an antenna requires a balanced drive, has a poor aperture efficiency and a narrow bandwidth. The antenna has a rather large thickness because it is designed to use the ground plane as a reflector. Another example of resonant dipole microstrip antennas utilizing capacitative coupling is contained in EMI-Varian Limited Bulletin PA2 11/73, entitled "Printed Antennae 2 - 36 GHz." In such an antenna the radiator elements are capacitatively coupled at various spacings to one or more feedlines running parallel to their E coordinate. The disclosed antenna has demonstrated low aperture efficiencies and poor side lobe control. A second class of microstrip antennas utilizing resonant dipole radiator elements employs conductive coupling of energy to radiator elements. Antennas of this class are disclosed in U.S. Pat. Nos. 3,803,623 (Charlot) and 3,811,128 (Munson) and by Munson (I.E.E.E. Transactions on Antennas and Propagation, January, 1974, pp. 74-78). The E coordinate dimension of the radiator elements is approximately λo/2√ε r μ r . The H coordinate dimension is commonly greater than the E coordinate dimension and may be several wavelengths long. The individual input impedance of such radiator elements at frequencies around resonance is typically in the convenient range of 50 to 150 ohms depending on element dimensions and dielectric substrate characteristics. A corporate feed network distributes energy between the transmission line and a plurality of microstrip radiator elements. A corporate feed network in microstrip comprises an interconnected pattern of thin conductive strips which connect the radiator elements into arrays. A terminal on the corporate feed network of an array serves for connection to a transmission line. Such a terminal may be connected directly to the transmission line or connected indirectly to the transmission line through additional corporate feed network strips. A corporate feed network may be provided by a sequence of power dividers and tapered feed line sections or other impedance transformers which serve to distribute the desired amount of energy directly from (to) the transmission line to (from) each radiator element. The lengths of the feed line sections determine the phase relationship between the transmission line and each radiator element and thus control the phase relationship between radiator elements. Two-dimensional arrays of up to four or possibly eight radiator elements interconnected by a corporate feed network can be designed to produce a good aperture efficiency in the range of 90 percent based on ground element area. For arrays of greater numbers of radiator elements a decreased aperture efficiency is observed with conventional corporate feed because the corporate feed network becomes increasingly more extensive. The more extensive feed network necessitates increasing the spacing between the radiator elements, with such increased radiator element spacing in turn significantly reducing the aperture efficiency. Such proliferating feed lines also become lengthy which increases feed line losses. The proliferating feed lines often have lengths of various multiples of dielectric wavelengths such that slight changes in frequency produce undesirable phase shifts between radiator elements. SUMMARY OF THE INVENTION The present invention provides improved distribution of energy to resonant dipole radiator elements in a microstrip antenna. Antennas utilizing the present invention can be designed to have an increased efficiency and an increased bandwidth when compared to other microstrip antennas utilizing resonant dipole radiator elements. The present invention utilizes thin conductive strips called bridge elements to distribute power to and control the phase relationship between such radiator elements. Each bridge element has a length providing approximately a phase reversal (in the range of 150° to 210° from end to end at the operating wavelength λo. Each bridge element directly and conductively joins two adjacent radiator elements with those two radiator elements being defined as being in the same array. The width of each bridge element is less than the H coordinate dimension of one of the radiator elements it joins and less than one-half the H coordinate dimension of the other radiator element it joins. Each array utilizing the present invention has a terminal on a radiator element off that radiator element's H coordinate. Such a terminal connects the array to an unbalanced transmission line either directly, or indirectly through a further feed network. In contrast, arrays utilizing corporate feed networks have terminals on the corporate feed network, which terminals connect the arrays to a transmission line. The present invention utilizes the phase reversal property that exists across a dipole radiator element in the E coordinate direction to distribute energy via one or more bridge elements to other radiator elements within the array. Accordingly, there is at least one radiator element in an array of the present invention which has either 1. two bridge elements, or 2. a bridge element and a terminal for connection to a transmission line joined to it at points of opposite phase. A simple form of the invention is a linear array of radiator elements that are series connected by bridge elements to form a chain-like structure of radiator elements that may or may not physically lie in a straight line. In a straight-line linear array having only one radiator element connected directly to a transmission line and operating as a transmitter antenna, power from the transmission line is distributed to the radiator elements that are electrically farther from the transmission line through the series connected radiator and bridge elements that are electrically closer to the transmission line. In a straight-line linear array having only one radiator element connected directly to a transmission line and operating as a receiver antenna, the increments of power received by other radiator elements pass through the series connected radiator and bridge elements that are electrically closer to the transmission line. Antennas utilizing the present invention do not require an elaborate corporate feed network and thus provide high efficiency by minimizing feed network losses and permitting close spacing of radiator elements. High efficiency antennas can achieve a desired antenna gain with a relatively small area of circuit board, thus offering the additional advantage of low weight and low cost. Antennas utilizing the present invention have surprisingly resulted in a significant increase in half-power bandwidth compared to conventional resonant dipole microstrip antennas. Therefore, antennas utilizing the present invention have a low sensitivity to changes in frequency and in the properties of the dielectric sheet. Antennas with uniformly illuminated arrays are easily designed with the present invention because they can be formed from modular building blocks. For example, a linear straight-line array may be easily formed once the geometries of the radiator element and bridge element are established by simple repetition of such elements. Once one array is formed, simple repetition may provide a plurality of arrays. Because each array requires only one terminal for connection to a transmission line, a plurality of such arrays can be formed into an antenna by a simple and hence easily designed corporate feed network. Arrays of the present invention are unexpectedly easy to match to common feed line impedances. In a typical situation the impedance at a terminal on one radiator element of an array may be inherently matched to 50 ohms with a voltage standing wave ratio (VSWR) of less than 1.5. The input impedance to one element is commonly capacitative; however, the addition of successive elements in an array progressively shifts the input impedance toward and into the inductive region. Such a resistive-inductive impedance can be easily compensated to become purely resistive by adding a small capacitative tab on the edge of the element having the terminal, with such a tab later being fabricated as part of the circuit board. If a terminal on an array for connection to a transmission line is on a central radiator element of the array, that radiator element can serve as a 180° phase shifter such that one terminal can be used to feed signals to or accept signals from radiator elements on both sides of such central radiator element to produce an antenna array whose beam direction is very stable with respect to changes in frequency and in the dielectric sheet properties such as dielectric constant and thickness. To a first order approximation, the E coordinate dimension of a dipole radiator element in relation to the dielectric constant determines a possible range of operating frequency for the radiator element. To a similar first order approximation, the bridge element which interconnects two radiator elements determines the phase relationship between the two radiator elements when they are operating as an antenna. In an array that utilizes the present invention and has a broadside beam, to a first order approximation there is 180° of phase shift across each radiator element and each bridge element such that each radiator element is in phase (360°) with respect to adjacent radiator elements with which it is interconnected. The radiator elements can be various sizes and shapes. The E coordinate dimension of each radiator element should be approximately λo/2√ε r μ r . The H coordinate dimension can be various lengths. The H coordinate dimension is greater than the width of the bridge element and may be several wavelengths long. If the H coordinate dimension is greater than about one dielectric wavelength, multiple bridge elements may be required between two radiator elements. Preferably the natural resonant frequency modes in the E and H coordinate dimensions for any given radiator element are different. Because the radiator element H coordinate is greater than the width of the bridge element, the characteristic impedance of the radiator elements considered as a section of transmission line will be lower than the characteristic impedance of the bridge elements. The individual radiator elements may be symmetrical or asymmetrical and each radiator element can conceivably have a different shape. While the radiator elements are often physically located adjacent to each other in the E coordinate direction, they can be physically located in other directions on the surface of the antenna dielectric sheet. However, it is important that the E coordinates of the respective radiator elements be approximately parallel regardless of the physical location of the radiator elements such that their radiation patterns will reinforce each other in a predetermined manner. The bridge elements can be various sizes and shapes as long as they provide approximately a phase reversal (150° to 210°) from end to end at the operating wavelength λo. Bridge elements can vary in width with narrower bridge elements having a higher characteristic impedance when considered as sections of a transmission line. Such characteristic impedance can be determined from Wheller's Wide Strip Approximation Chart (Microwave Engineers Handbook, Vol. I, 1971, publisher: Horizon House-Microwave Incorporated, p. 137) which gives impedance in terms of strip width, dielectric constant and dielectric thickness. It is believed that if bridge elements get too narrow they will not effectively transmit energy. Maximum bridge element width is such that the bridge element is less than the H coordinate dimension of one of the radiator elements it joins and less than one-half the H coordinate dimension of the other radiator element it joins. It is believed that if the bridge elements are too wide they will interfere with the ability of the radiator element to radiate. For a given bridge element the length is adjusted to provide the desired phase relationship. Relatively speaking, a narrower bridge element will have a longer length for the same phase shift. Once an array of the present invention is built, it is believed that similar arrays can be designed to operate at other desired frequencies by suitably scaling the array pattern and dielectric sheet thickness in the approximate ratio of the desired wavelength to the wavelength of the working model. BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic perspective view of a first embodiment of an antenna according to the present invention; FIG. 2 is a plan view of a second embodiment of an antenna according to the present invention; FIG. 3 is a Smith Chart showing the complex input impedance of antennae constructed as in FIG. 2 with one to four radiator elements; FIG. 4 is a plan view of a third embodiment of an antenna according to the present invention; FIG. 5 is a fragmentary drawing showing the relationship between the radiator and bridge elements in FIG. 4; FIG. 6 is a plan view of a fourth embodiment of an antenna according to the present invention; FIG. 7 is a plan view of a fifth embodiment of an antenna, one that has a plurality of arrays, each of which utilizes the present invention; FIG. 8 is a plan view of an array that is essentially identical to each of the arrays in FIG. 7; FIG. 9 is a fragmentary drawing showing the relationship between a feed terminal, a radiator element and a bridge element of the array in FIG. 8; and FIG. 10 is a plot of the E and H plane radiation patterns of the antenna in FIG. 7. DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, an antenna 20 includes a dielectric sheet 21 which uniformly separates a ground element 22 from radiator elements 31 through 36, bridge elements 41 through 45 and a capacitative tab 46. The antenna 20 is made from a double copper-clad low-loss dielectric sheet 21 by etching one copper layer to form radiator elements 31 through 36, bridge elements 41 through 45 and capacitative tab 46. The dielectric sheet 21 is polytetrafluoroethylene reinforced with glass fiber cloth with the sheet having properties in accordance with U.S. military specification MIL-P-13949E Grade GX with a relative dielectric constant ε r of about 2.45, a relative permeability μ r of 1.0 and a thickness of about 0.76 mm. Each copper layer is about 34 micrometers thick. The rectangular radiator elements 31 through 36 are each 1.38 cm by 2.05 cm and are located on 2.54 cm centers. Each bridge element 41 through 45 is 0.2 cm wide and conductively joins a pair of adjacent radiator elements diagonally across the space between them. The dielectric sheet 21 and the ground element 22 are each 2.54 cm by 14.7 cm in the broad surface. The antenna is fed at terminal 47 from a 50-ohm unbalanced coaxial transmission line (not shown) that passes through the ground element from the backside. The antenna has a broadside beam (principal lobe perpendicular to the antenna surface) at 6406 MHz, has about 90% aperture efficiency based on ground element area when matched with the tab 46 and has an input voltage standing wave ratio (VSWR) of 1.3 terminating a 50-ohm line at such frequency. It is believed the broadside beam indicates all radiator elements are in phase with respect to each other. The aperture efficiency figure includes the VSWR mismatch and is based on the theoretical gain G = 4πA/(λo) 2 where A is the ground element area and λo is the free space wavelength. The antenna's first side lobes in the E plane pattern of maximum gain are 12.6 db and 14.2 db below maximum gain. The antenna's measured half-power beam width in the E plane at frequency of maximum gain is 14.2°. The theoretical beam width for a uniformly illuminated aperture 14.7 cm long is 16.1°. Such theroetical beam width is based on the formula (50.6) (λo)/L where λo is the free space wavelength and L is the length of the aperture (ground element) in that plane. The antenna's beam is frequency steerable over a total angle of 20° when the frequency is scanned from 6112 MHz to 6742 MHz. Applicant believes that when the array in FIG. 1 is operating as an antenna with a broadside beam, to a first order approximation there is a phase reversal respectively across each radiator and bridge element. For example, radiator element 32 would have 180° of phase shift between points 52 and 53; and bridge element 42 would have 180° of phase shift between points 53 and 54 where it conductively joins radiator elements 32 and 33. Thus radiator elements 32 and 33 would be in phase with respect to each other. Under such circumstances, it is believed that the incident currents, resonant currents and reflected currents all synchronously reinforce each other. For example, the incident currents entering radiator element 32 at 52, the reflected currents entering radiator element 32 at 53 and the resonant currents within radiator element 32 would synchronously reinforce each other. It may be desirable to slightly shorten the E coordinate dimension of the radiator element 36 electrically farthest from the terminal 47 to optimize performance. It is believed that this adjusts the phasing of the reflected currents and compensates for the absence of additional bridge and radiator elements. The bridge elements in FIG. 1 each join a pair of adjacent radiator elements diagonally across the space between such radiator elements, permitting close spacing of radiator elements for high efficiency. Such an arrangement drives adjacent radiator elements such as 32 and 33 on opposite sides of their respective E coordinates such as at 52 and 54 such that any cross polarization of the E fields in adjacent radiator elements is self-canceling in the far field. By connecting bridge elements such as 41 and 42 to a radiator element such as 32 at points such as 52 and 53 which define a line parallel to the E coordinate dimension, the currents passing through the radiator element are parallel to and add to the resonant currents within the radiator element. If bridge elements 42 and 44 were arranged such that they were parallel to bridge elements 41, 43 and 45 while still joining their respective radiator elements diagonally across the space between such radiator elements, the antenna would still radiate but the radiated E plane would be slightly skewed from the E coordinate direction of the radiator elements. A second embodiment utilizing the present invention is an antenna 60 shown in FIG. 2. Its elliptical radiator elements 61 through 64 each have an E coordinate dimension of 1.52 cm, an H coordinate dimension of 2.03 cm and are located on 3.0 cm centers. Bridge elements 71 through 73 are each 0.2 cm wide and conductively join respective radiator elements along a center line as shown. A capacitative tab 74 is for impedance matching. The antenna is fed at terminal 75 from an unbalanced 50-ohm coaxial transmission line (not shown). A dielectric sheet 76 and a ground element (not shown) are each 2.54 cm by 11.5 cm in the broad surface. The antenna 60 has an efficiency of about 78 percent at 6959 MHz, the frequency of maximum gain, when properly matched to a 50-ohm line. Its principal lobe is tilted 3° to 8° off broadside depending on frequency away from terminal 75, indicating the bridge elements are slightly longer than those for a broadside beam. The antenna 60 will not operate efficiently at a frequency that is low enough to bring the principal lobe to broadside. FIG. 3 represents the complex input impedance at terminal 75 as a function of frequency on a Smith Chart normalized to 50 ohms without a matching tab 74 as the antenna 60 was built starting with element 61 and successively adding units of one bridge element and one radiator element. Curves 77, 78, 79 and 80, respectively, represent the complex impedance with 1, 2, 3 and 4 radiator elements. As successive units of one bridge element and one radiator element were added, the resistive impedance in the neighborhood of 6950 MHz remained relatively constant while the capacitative reactance progressively decreased. In the four-element configuration the complex impedance moved into the inductive region. FIG. 3 shows that the four element array has an inherent unmatched minimum VSWR of 1.83 at about 6960 MHz. By proper placement of the capacitative tab 74, the input VSWR for the four element array was reduced to less than 1.2 over the range 6950 to 7000 MHz. The impedance, referenced to the back side of the board where the coaxial center conductor passes through a hole in the ground element to attach to terminal 75, was measured using a slotted line impedance meter. By adjusting the size and location of the capacitative tab it is possible to not only reduce the VSWR but also move the frequency of minimum VSWR around in a limited range. Prior to making such an adjustment an array of radiator and bridge elements is established. Then, a movable tab is made from pressure-sensitive copper foil tape such as Scotch brand Electrical Tape No. X1194. The tab is made sufficiently large such that it can project beyond and overlap the radiator element having the feedpoint. The tab is adjusted while the terminal is connected by a coaxial connector through the ground element to a VSWR bridge such as Wiltron Company Model 64A50, 3 to 8 GHz. The swept frequency output from the bridge is observed on an oscilloscope while a tab is moved along the periphery of the radiator element having the terminal with the tab's size and location being varied. It has been observed that far more versatility is achieved in reducing VSWR and in adjusting the frequency of minimum VSWR than would be expected by a simple theory of pure capacitative shunting. Once the size and location of a tab is determined it may be reproduced as part of the copper-clad etching process. Although the array in FIG. 3 is impedance matched to a transmission line at terminal 75, the radiator elements are not impedance matched to their respective bridge elements within the array itself. FIG. 4 shows a third embodiment wherein the dielectric sheet 81 is 1.5 mm thick. The elliptical radiator elements 82 through 92 each have an E coordinate dimension of 1.52 cm, an H coordinate dimension of 2.03 cm and are located on 2.54 cm centers. The bridge elements 93 through 102 are each 0.25 cm wide and conductively join to the radiator elements as shown in the fragmentary drawing of FIG. 5. The dimensions A are 6.35 mm. Capacitative tabs 103 and 104 are attached to element 87. This antenna is fed by an unbalanced 50-ohm coaxial transmission line, the center conductor of which passes through the ground element and contacts terminal 105 on radiator element 87. By placing the terminal 105 on a central radiator element, it is possible to drive the radiator elements on both sides of element 87 in phase while utilizing element 87 as both a phase reversing element and a radiator element. This central feed provides a desired broadside beam direction that is substantially independent of variations in frequency and variation in the dielectric constant and thickness of the dielectric sheet. This antenna exhibits side lobes 16.2 db and 17.5 db below maximum gain which is believed to indicate the radiation pattern can be tapered by using long arrays. The half-power beam width of the antenna is 8.5° compared to a theoretical beam width of 8.1° if the aperture were uniformly illuminated. By placing tabs 103 and 104 on radiator element 87 the input VSWR was reduced to less than 1.05. The array in FIG. 4 has a bandwidth of 5% within which the input VSWR remains less than 1.7. It is believed that interaction among elements of the array maintains the input VSWR of arrays, particularly those with many elements, at a desirably low value over a large frequency range. FIG. 6 shows a fourth embodiment wherein the dielectric sheet 111 is 0.76 mm thick. Each of the rectangular radiator elements 112 through 120 have an E coordinate dimension of 1.38 cm and they are on 2.30 cm centers. The H coordinate dimension of radiator elements 112, 113 and 114, 115 and 116, 117 and 118, 119 and 120 are respectively 2.95 cm, 1.84 cm, 1.33 cm, 0.82 cm and 0.6 cm. The bridge elements are each 0.2 cm wide, approximately 1.5 cm long and they are attached to their respective radiator elements as shown with the dimension B being 0.8 cm. A terminal 121 for connection to an unbalanced transmission line and a capacitative matching tab 122 are on radiator element 112. Radiator elements 115 and 116 have slits cut in them as shown to minimize cross polarization because these elements are almost square. The antenna in FIG. 6 exhibits side lobes 19 db and 20 db below maximum gain which is believed to indicate the radiation pattern can be tapered by varying the size of the radiator elements. The half-power beam width of this antenna is 12.3° compared to an estimated theoretical beam width of 10.4° if the aperture were uniformly illuminated. FIG. 7 shows a fifth embodiment wherein eight essentially identical three element arrays 125 are fed by a conventional corporate power divider feed network 126 that includes two 180° phase shifters. FIG. 8 shows a three element array 125 that is essentially identical to those in FIG. 7. Dielectric sheet 130 and a ground element (not shown) are 2.48 cm by 7.2 cm. The dielectric sheet is 0.76 mm thick. Elliptical radiator elements 131, 132 and 133 each have an E coordinate dimension of 1.52 cm, an H coordinate dimension of 2.03 cm and are located on 2.54 cm centers. Bridge elements 134 and 135 are each 0.2 cm wide. A terminal 136 for connection to an unbalanced transmission line is on radiator element 133. FIG. 9 shows in a fragmentary drawing the location of the terminal 136 and the bridge element 135 with respect to radiator element 133. The dimension C is 0.4 cm and the dimension D is 0.5 cm. The bridge elements 134 and 135 join the radiator elements 131 and 132 in similar fashion. The three element array 125 in FIG. 8 has a maximum gain at approximately 6770 MHz with unmatched terminal 136 connected to a 50-ohm transmission line. The efficiency of this array approaches 100% based on ground element area and has an unmatched VSWR of less than 1.4 into a 50-ohm input at 6774 MHz. Referring again to FIG. 7, eight arrays 125, essentially identical to the array in FIG. 8, are shown interconnected by a conventional type corporate feed network 126. The dielectric sheet 140 is 9.2 cm by 15.0 cm by 0.76 mm and the arrays 125 are spaced on 2.30 cm centers in the H coordinate direction as shown by dimension F. The arrays 125 are spaced apart 2.92 cm in the E coordinate with such spacing being center to center between adjacent radiator elements in different arrays as shown by dimension G. A terminal 136 on each array is connected to a 100-ohm one-eighth wavelength section of line 141 which impedance matches and converts the complex impedance at terminal 136 to approximately 85 ohms pure resistive at the other end of the line 141. Two of the lines 141 are combined to produce 42.5 ohms at reference character 142 with this line being tapered and combined again by corporate feed network techniques well known in the art. To protect the antenna pattern in FIG. 7 from the environment, it was covered with a 0.38 mm thick sheet of similar dielectric material. This additional sheet was heat bonded to the etched surface of the antenna using a 0.038 mm layer of polymonochlorotrichloroethylene film fused in place under 50 psi at 400°F (204°C). FIG. 10 is a plot of the E and H field patterns of the antenna in FIG. 7 referenced to 0 db. The observed gain exceeds 90% of the theoretical gain based on ground element area at 6650 MHz with the first side lobes in the E plane being down 12 db and 12.5 db from maximum gain. The bandwidth over which the input VSWR is less than 2.0 is 285 MHz or 4.3%.

Microstrip antenna having one or more arrays of resonant dipole radiator elements. The radiator elements have an E coordinate dimension of approximately λo/2√ ε r μ r . Bridge elements directly and conductively join adjacent pairs of radiator elements to provide energy distribution and the desired phase relationship. The radiator elements and bridge elements are in a broad surface which is uniformly spaced from a ground element by a dielectric sheet.

RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 12/399,893 filed Mar. 6, 2009, titled “TRANSPORTATION DEVICE WITH PIVOTING AXLE”, which claims benefit under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/064,458, filed Mar. 6, 2008, entitled “TRANSPORTATION DEVICE WITH PIVOTING AXLE”, the entireties of which are hereby incorporated by reference herein and made a part of this specification. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to conveyances including skateboards, scooters, roller skates, as well as low profile skateboards, low profile roller skates, and other forms of conveyances. Some embodiments can include skateboards having a unitary platform with one or more inclined planar surfaces that serve as bearing surfaces for steerable axles and wheels. 2. Description of the Related Art There is a great deal of prior art describing various human powered platforms that can be turned by tilting the platform about an axis parallel to the direction of travel. For these devices, when the rider tilts the platform from side to side, one or two sets of wheels are induced to turn about an axis which is not parallel with the ground. In this way, skateboarders “lean into the turn in a way that facilitates balance during turns. Both skateboards and roller skates may include this type of tilt-based turning. In order to mechanically link tilting of the platform with turning of the wheels about a vertical axis, skateboards include a device called a truck. Conventional skateboard trucks are formed from metal or plastic, and are bulky, and usually contain four primary-components: a truck hanger, a base plate, a kingpin, and bushings. These trucks are conventionally located under the horizontal platform that the rider stands on, and the wheels are also usually located underneath the platform. Examples of a conventional skateboard truck include the Randal R-II, or the Destructo Mid Raw 5.0 Skateboard Truck. In the past, some skateboards have been designed to be used and then conveniently and easily carried with the user when the user is not riding the skateboard. Various features have been designed to meet this portability objective: skateboards that are of low weight, are foldable, are collapsible, or are readily disassembled. However, these skateboards have employed, for the most part, conventional trucks. Collapsible push scooters including those with lowered platforms are popular. Some of these have relatively short distance between the road surface and top of the riding platform. These scooters are typically made from metal, and although the steering handle collapses and folds, they are still bulky and cumbersome when in their most compact position. There are also a variety of skateboards available with lowered decks so that the rider can push the skateboard more readily. Therefore there is a need for conveyances with improved steering systems, including those that are lighter, more compact, and assembled from fewer parts. SUMMARY OF THE INVENTION Accordingly, in a first aspect, the invention provides a device for transportation comprising a platform comprising a ride surface upon which a rider may place a foot to ride the device in a direction of travel on the ground, so that the ride surface is an upper surface in use, the platform having a length extending in that direction and a forward portion and a rearward portion; a pair of wheels adjacent either the forward portion or the rearward portion and at least one wheel adjacent the other portion; an axle extending between the pair of wheels and located in an axle mounting system attached to the platform; the axle mounting system comprising an axle bearing surface and a pivot member having a pivot surface, the axle bearing surface and the pivot surface being inclined towards each other and each of the axle bearing surface and the pivot surface being inclined with respect to the ride surface, the pivot surface creating a pivot about which the axle can pivot to provide, in use, a turning function for the device and the axle bearing surface extending transversely to said length and providing a surface that supports the axle during said pivoting of the axle and turning of the device. Typically the axle mounting system is attached to and below the platform. Then, the axle bearing surface and pivot surface, in such preferred embodiments, are inclined towards each other towards the platform. In one embodiment, the axle bearing surface is located or extends adjacent each of the pair of wheels. This is to extend support to just inboard of the wheels, which in some embodiments are outside the perimeter of the foot of a rider. This reduces the bending stresses on the axle, and reduces the weight of the board. Thus, in one embodiment, the axle bearing surface has a length substantially the same as the length of the portion of the axle between the wheels. In one embodiment, the pivot member surface opposes the axle bearing surface. In one embodiment, the pivot member comprises a portion having a substantially triangular cross-section. In one embodiment, the surface of the pivot member is curved. In one embodiment, the axle bearing surface comprises a substantially planar portion. In one embodiment, the axle bearing surface comprises a curved portion. In one embodiment, the axle bearing surface comprises two or more substantially planar portions. In one embodiment, the location of the contact portion on the surface of the pivot member changes as the axle pivots about the pivot surface. In one embodiment, the location of the contact portion on the surface of the pivot member changes as the axle pivots about the pivot member surface, and the contact portions on the surface of the pivot member defined as the axle pivots describe a curve substantially parallel to a vertex of an angle between the surface of the pivot member and the bearing surface. In one embodiment, the bearing surface is a discontinuous surface. In one embodiment, the surface of the pivot member is a discontinuous surface. In one embodiment, the device further comprises a spring or spring like structure contacting the axle, and opposing the axle bearing surface. In one embodiment, the surface of the pivot member is curved, and the curved surface of the pivot member comprises a portion having a radius of curvature of about 140 to about 170 mm. In one embodiment, the surface of the pivot member is curved, and the curved surface of the pivot member comprises a central portion having a first radius of curvature, a first outboard portion having a second radius of curvature, and a second outboard portion having a third radius of curvature. In one embodiment, the surface of the pivot member is curved, and the curved surface of the pivot member comprises a central portion having a first radius of curvature, a first outboard portion having a second radius of curvature, and a second outboard portion having a third radius of curvature, wherein the first radius of curvature is greater than the second or third radii of curvature. In one embodiment, the surface of the pivot member is curved, and the curved surface of the pivot member comprises a central portion having a first radius of curvature, a first outboard portion having a second radius of curvature, and a second outboard portion having a third radius of curvature, wherein the first radius of curvature is greater than either of the outboard radii, the outboard radii preferably being equal to one another. Typically, the radius of curvature of the curved pivot member, whether as a constant curve, or the average radii of such multiple radii, is about 5 to 10 inches, preferably about 6-8 inches. In one embodiment, the angle between the pivot member surface and the axle bearing surface is about 70 to about 110°. In one embodiment, the surface of the pivot member is curved, and the curved surface of the pivot member comprises a central portion having a first radius of curvature, a first outboard portion having a second radius of curvature, and a second outboard portion having a third radius of curvature, wherein the first outboard portion and the second outboard portion are on opposite sides of the central portion. In one embodiment, the angle between the surface of the pivot member and the bearing surface measured at a central portion of the pivot member is different from the angle measured at an outboard portion of the pivot member. In one embodiment, the pair of wheels is adjacent the forward portion. In one embodiment, the pair of wheels is adjacent the rearward portion. In one embodiment, the platform has a top surface defining a first plane, the axle bearing surface forming an angle with a second plane parallel to the first plane being about 26 to about 45 degrees. In one embodiment, the platform has a top surface defining a first plane, the axle bearing surface forming an angle with a second plane parallel to the first plane being about 26 to 45 degrees, more preferably about 30 to about 40 degrees. In another embodiment, a method is presented for turning a transportation device, the method comprising pivoting an axle about a pivot member surface, wherein the pivot member surface contacts the axle and is disposed at an angle to a bearing surface and has a fixed position in relation to the bearing surface, the pivot member surface opposing the bearing surface and the bearing surface slidably contacting the axle, the axle extending between a pair of wheels positioned adjacent a forward portion or rearward portion of a ride surface suitable for placement of a rider's foot thereupon and the ride surface having at least one wheel adjacent the other portion of the ride surface. In another embodiment, there is provided a device for transportation comprising a platform upon which a rider may place a foot to ride the device in a direction of travel on the ground or similar surface, the platform having a length extending in that direction and a forward portion and a rearward portion; a pair of wheels adjacent either the forward portion or the rearward portion and at least one wheel adjacent the other portion; an axle extending between the pair of wheels and located in an axle mounting system attached to the platform, the axle being configured to pivot on an inclined surface, so that when a user leans to turn he device the platform tilts into the turn direction and the center of the top surface of the platform increases in altitude as the axle moves on the inclined surface to establishes a new position thereon. The inclined axle bearing surface may the other characteristics described herein. Preferably, the axle mounting system is attached to the underside of the platform. The device may further comprise a member about which the axle pivots as the axle moves on the inclined surface. The pivot member may a curved surface and/or the other characteristics described herein. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood from the following detailed description thereof taken in connection with the accompanying drawings, which form part of this application, and in which: FIG. 1 shows a perspective view of the underside of the skateboard with a rider's shoe placed in the riding position. FIG. 2 shows a perspective view of the front of the skateboard with the rider's shoe placed in the riding position. FIG. 3 shows a perspective view of the skateboard with the front left wheel removed to reveal the integral truck assembly. The primary elements of this truck are the inclined axle bearing surface 38 , the axle, 36 , the compression springs 44 R and 44 L, the pivot member 40 , and the axle retention device 45 . FIG. 4 shows a perspective view of the skateboard indicating how the integral truck produces a linkage between tilting of the platform about an axis parallel to the principle direction of travel and turning of the axis about an axis normal to the inclined axle bearing surface 38 . FIG. 5 shows a perspective view of a skateboard molded from a thermoplastic, with weight reduction features found in typical thermoplastic moldings, and molded flanges on the top surface of the platform intended to increase its resistance to bending about an axis parallel with the rear axle 50 . FIG. 6 shows a perspective view of a deadman's brake assembly, with the fender 48 partially cut away. FIG. 7 shows a perspective view of the axle 36 including a retention ring 64 L inboard from the left wheel that is used in conjunction with a second ring adjacent to the right wheel 64 R to keep the axle 36 from sliding parallel to its axis. FIG. 8 a shows a side view of a deadman's brake that is formed as an integral part of the unitary skateboard platform with this brake engaged to contact a wheel to stop the motion of the skateboard. FIG. 8 b shows a side view of the deadman's brake with the brake disengaged from the wheel by the application of a force F 2 to the brake by the application of pressure downward by the user's foot. FIG. 8 c shows a top view of this brake formed as an integral part of the unitary skateboard platform. FIG. 9 shows a perspective view of a skateboard an elastic strap 68 fastened to the underside of the platform. It also shows two partial front fenders 70 R and 70 L that are rigidly fixed to the foot support platform 32 to prevent the rider's foot from contacting the front wheels 34 R and 34 L. FIG. 10 shows a perspective view of a skateboard with the elastic strap 68 wrapped around the rider's shoe to held the shoe firmly to the top of the skateboard. FIG. 11 shows a view of a skateboard truck with an extended pivot member 80 , creating a gravity spring to provide forces that tend to restore the axle to the position normal to the centerline 82 of the skateboard. FIG. 12 shows the motion of the axle during a tilt induced turn, with the extended pivot member 80 . The point of contact between the axle 36 , and the extended pivot member 80 (the “pivot point”) shifts towards the wheel on the inside of the turn, where the term “inside” is defined in the conventional way. FIG. 13 shows a view of a non-planar inclined axle bearing surface comprising of two parts with differing slopes 88 A and 88 B. FIG. 14 shows a curved extended pivot member 90 . FIG. 15 shows an overmolded axle block 92 . This version of the axle block includes an integral curved extended pivot member that engages with the surface 39 , and a smooth planar section that is flush with the inclined axle bearing surface 38 . FIG. 16 shows the axle and curved pivot member. FIG. 17 is a front view of the skateboard showing the relative position of wheels and axle to the foot support platform. FIG. 18A is an oblique bottom view showing the curved pivot member and axle bearing surface. FIG. 18B is a side view showing the relative orientation of the curved pivot member and axle bearing surface to the ground. FIG. 19A is an oblique top view of one embodiment of the device showing the brake actuator and the fenders. FIG. 19B is a bottom view of one embodiment showing discontinuous surfaces for the axle bearing surface and the pivot member. FIG. 20A is an oblique bottom view of one embodiment showing discontinuous axle bearing and pivot member surfaces, vertex, and fenders. FIG. 20B is a side view of one embodiment showing relative angles of the angle between the pivot member surface and the bearing surface. FIG. 21 is a diagram of the device showing the components of the normal ray. FIG. 22 is a bottom view of the device showing the change in contact portion for different turning positions of the axle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The following description and examples illustrate some exemplary embodiments of the disclosed invention in detail. Those of skill in the art will recognize that there are numerous variations and modifications of this invention that are encompassed by its scope. Accordingly, the description of a certain exemplary embodiment should not be deemed to limit the scope of the present invention. In addition, the Figures are not to scale and some features may be exaggerated or minimized to show details of particular elements while related elements may have been eliminated to prevent obscuring other aspects. Generally speaking, the systems described herein are directed to wheeled conveyances including, for example, low profile wheeled conveyances, such as skateboards, scooters, kick scooters and/or roller skates. Referring to the Figures, some embodiments of the conveyance disclosed herein include a foot support platform 32 having an integral, full-width or partial-width inclined axle bearing surface 38 which supports a transverse axle 36 . In one embodiment, the inclined axle bearing surface 38 can be a planar surface and can form an angle of between about 10° and about 70° with the horizontal plane, said plane being defined as parallel to the travel surface depending, for example, on the steering responsiveness required. The axle 38 supports a pair of wheels 34 R and 34 L. The inclined axle bearing surface 38 supports the axle 36 across all or part of its span between the wheels 34 R and 34 L, but in some embodiments, said surface 38 can support the axle 36 in the regions adjacent to the wheels 34 R and 34 L and can reduce the bending moment applied to the axle. The wheels 34 R and 34 L can be conventional skateboard or roller skate or in-line skate or scooter wheels or other types of wheels, and in some embodiments a pair of roller or plain bearings, not depicted in these figures, can be located between the solid body of the wheel and the axle. The axle mayor may not rotate about its own longitudinal axis when the skateboard moves, and the wheels rotate. The axle can be offset from the center of the wheel in a vertical and/or horizontal direction, such as is shown in FIG. 17 . The wheels 34 R and 34 L may be retained at a specific location along the length of the axle 36 by any conventional means commonly used, including those used for skateboard, roller skate, in-line skate, or scooter wheels, but other methods can be used as well. The method of retention is not depicted here. A pair of compression springs 44 R and 44 L can be compressed by the axle 36 against a spring bearing surface 39 that can be an integral part or added part of the foot support platform. These springs may be rubber blocks, cell springs, leaf springs or any other type of member capable of supporting compression parallel to the surface of the inclined axle bearing surface 38 and perpendicular to the axle 36 . The compression springs serve to restore the axle to a position perpendicular to the long axis of the conveyance 82 (see FIG. 11 ), when no torque is applied by the user about said axis 82 . The compression springs therefore function to keep the conveyance running in a straight line or particular direction unless the user deliberately tilts the conveyance to make a turn or change the direction. In some embodiments, a turning bias can be built into the conveyance, such as by adjustment of the compression springs, the axle bearing surface or the pivot member design or position, such as to correct for an off-balance load, sloped travel surface, etc. or to favor, cause, or build-in a turning condition to the conveyance. In some embodiments, tension springs can be used in place of or in combination with compression springs. Suitable locations for tension springs include in front of and below the axle instead of the compression springs 44 R and 44 L. A pivoting axis 43 may be formed by the inclusion of a pivot member 40 formed in the shape of a triangular prism, or some other shape, including those which have a ridge configured to contact the axle. In some embodiments, springs for different rider weights, ability level, size, or performance can be provided with or separate from the conveyance for tuning the operation of the conveyance, or for other reasons, such as maintenance. In some embodiments, the spring response on operability can be adjusted, such as by including provision to adjust the lateral position of the springs on the spring bearing surface 39 . In some embodiments, a single rear wheel 46 can be supported by an axle 50 inserted through holes or indentations in the foot support platform, and retained by any conventional means. The wheel 46 can be positioned between the platform forks 49 R and 49 L and retained in an appropriate position by suitable methods including spacers, axle design features (such as interference fit, bumps, indentations, protuberances, etc.), nuts, etc. It is also possible to mold suitable spacers or other suitable features as part of the foot support platform 32 . In other embodiments, a single wheel, similar to that described for the rear can be utilized in the front with a system comprising an axle and inclined axle bearing surface, as described herein, in the rear, or a system comprising an axle and inclined axle bearing surface, as described herein, in both the front and the rear. A fender 48 can be included as part of a foot support platform to cover a single wheel 46 or a pair of wheels. The fender 48 could be molded as part of a foot support platform in a single molding operation, and can have sufficient rigidity to serve as a rest platform for a rider's ground engaging foot (the “pushing foot”). At the same time, the fender 48 could be designed with sufficient flexibility that it could engage the wheel to serve as a friction brake when a rider's weight was transferred from the front foot to the rear foot to press down substantially on said fender 48 . In some embodiments, fenders can be utilized, such as by molding as part of the foot support platform 32 or otherwise, for example to prevent the rider's foot from engaging the rotating wheels 34 R and 34 L. Partial front fenders 70 R and 70 L are shown in FIG. 9 and FIG. 10 . In some embodiments, fenders or partial fenders can prevent the axle from being unduly loaded in bending in the event that the user inadvertently stepped on the conveyance while it was upside down on the ground. An optional deadman's brake assembly can be composed from an angled lever 58 , a torsion spring 60 a depression 61 in the foot support platform body 32 and an axle 62 . If the user steps-off or falls off the conveyance, the torsion spring 60 presses the rear part of the angled lever 58 against the rear wheel 46 and slows or stops the conveyance Instead of using a torsion spring 60 , a compression spring may be inserted between the depression 61 in the foot support platform body 32 and the angled lever 58 to provide the deadman's brake action An alternative version of an optional deadman's brake is formed as an integral part of the foot support platform in order to reduce the number of parts and simplify assembly. For example, the brake 66 can be formed so that in the unstressed state it protrudes above the plane of the conveyance platform 32 and engages the rear wheel 46 as depicted in FIG. 8A . When the rider presses down on the brake 66 with his heel, then the brake shoe 66 disengages from the rear wheel 46 as depicted in FIG. 8B . In some embodiments, an axle bearing surface 38 can be positioned at an angle to a pivot member 40 , 80 or 90 . The bearing surface can be monoplanar as shown in FIG. 1 , or multiplanar or curved, as shown in FIG. 13 . In various embodiments, the curved or multiplanar character can be in a direction parallel to the long axis of the axle, at an angle to the long axis of the axle, or both parallel and at an angle to the long axis of the axle. In some embodiments, the axle bearing surface can extend substantially from one end of the axle to the other or from one wheel to the other. In some embodiments, the axle bearing surface can extend for a different distance over the length of the axle, such as 90% of the distance between the ends of the axle or the distance between the wheels, or for about 80% or for about 70% or for about 60% or for about 50% or for about 40% or for about 30% or for about 20% or less. As the extent of the axle bearing surface decreases, the axle can be made stronger, such as through dimensioning of the axle or through the selection of the materials used for the axle. Also, as the extent of the bearing surface decreases, the bearing surface can be made stronger, such as by selection of materials used for its construction. In some embodiments, the axle bearing surface can be removable, such as for replacement due to wear or to change the turning characteristics of the device, or for some other reasons including cosmetic. In some embodiments, the pivot member or its contact surface with the axle can be removable, such as for replacement due to wear or to change the turning characteristics of the device, or for some other reasons including cosmetic. Different shapes as well as materials and material hardness/resilience can be utilized for the bearing surface and the pivot member and pivot member surface, as desired such as for different turning or performance characteristics. The pivot member 40 can have a narrow contact region for contacting the axle, such as with a triangular cross-section as shown in FIG. 1 , or some other shape that presents a narrow or sharp surface to the axle. Suitable other shapes include those having a cross-section related to or including a square, rectangle, pentagon, teardrop, round or other shape. The narrow or sharp surface can also be truncated. In some embodiments, the pivot member can be a protruding portion from another part, such as the foot support platform a base structure, or another part. In one embodiment, as shown in FIG. 11 , the pivot member 40 defining a single pivot axis 43 is replaced with an extended pivot member 80 . The extended pivot member 80 is shaped so that the point or area of contact between the axle and the pivot member 80 shifts towards the inside of the turn, when the conveyance is tilted as depicted in FIG. 12 . A curved version of the extended pivot member 90 is depicted in FIG. 14 . Another version of a curved extended pivot member is shown in FIG. 16 , where the extended pivot member 90 has a curved face convex away from one end of the foot support platform. This curved face approaches or intersects the axle bearing surface 38 along a curved line 94 , where the ends of the curved line 94 curve upward and toward one end of the foot support platform 32 . In some embodiments, the pivot member 90 and the axle bearing surface 38 can be separated somewhat, such as with a gap or an intervening material, wherein the intervening material is flush, protrudes out, or is recessed from the surface of the pivot member 90 and/or the axle bearing surface 38 . In operation, when the rider leans or otherwise causes a turn, the foot support platform 32 will tip, with one edge of the foot support platform 32 moving toward the axle 36 , and the other edge moving away from the axle 36 . As the foot support platform 32 tips, the axle 36 shifts its contact zone 107 with the pivot member 90 to a new zone closer to the edge of the foot support platform on the side where the edge of the foot support platform 32 moved toward the axle, as shown in FIG. 22 . This axle movement results in the axle 36 pivoting with a component of the pivoting in a plane substantially parallel to plane of the travel surface or the top of the foot support platform 51 , with the wheel 34 R or 34 L at one end of the axle moving forward and the wheel 34 L or 34 R on the other end of the axle moving rearward, in relation to the direction of travel, causing a turning effect. Depending on the location and orientation of the axle bearing surface 38 and the pivot member 40 or 80 or 90 , the direction and magnitude of the turning effect can be varied, such as to be more sensitive, less sensitive, to turn in the direction of leaning or compression of the foot support platform 32 toward the axle 36 or away from the direction of leaning or compression of the foot support platform 32 toward the axle 36 . When the rider shifts position to move in a different direction, the contact zone 107 of the axle 36 with the pivot member 80 or 90 will shift as well, with the axle 36 contacting different points along the pivot member 80 or 90 related to the curved line 94 interface of the pivot member 80 or 90 and the axle bearing surface 38 . In FIG. 18A , an embodiment of a curved extended pivot member 80 having an approximately constant radius of curvature is shown. In other embodiments, the curved extended pivot member 90 can have a variable radius of curvature, such as with the central portion having a larger (flatter) radius of curvature than the outboard portions. Such a variable curvature can be advantageous, for example, in providing increased straight line stability, with minor shifts by a rider causing only small shifts in the axle position, while still allowing sharp turns. Suitable amounts of curvature include radii of about 80 to about 300 millimeters, while some embodiments can have radii of about 110 to about 220 mm or about 120 to about 180 mm, with some special embodiments having even higher or lower amounts of curvature. Suitable degrees of curvature can relate to the angle the bearing surface 38 forms with the horizontal plane, the sharpness of the turn desired, the dimensions of the foot support platform 32 , the size of the rider, etc. In FIG. 18B , the angular relationship of one embodiment of a curved extended pivot member 90 to an axle bearing surface 38 is shown. The included angle between the axle bearing surface 38 and the curved extended pivot member 40 can be any suitable angle, including angles of about 45 to about 135°. In some embodiments, the angle can be about 75 to about 110°, or about 85 to 95°. The angle between the axle bearing surface 38 and the horizontal plane 93 , can be about 10 to about 70°. In some embodiments, this angle can be about 20° to about 50°, or about 20° to about 40°, or about 25° to about 35°. Changes to either of these angles can provide the ability to, for example, adjust the turning response of the device as desired. In another embodiment, as illustrated in FIG. 13 , a pivot member with a ridge axle contact area is used, but the inclined axle bearing surface is no longer planar 88 A and 88 B. The mode of action will be described later in this document. In some embodiments, a non-planar inclined axle bearing surface can be combined with an extended pivot member or a curved extended pivot member. In some embodiments, the face of the extended pivot member or curved extended pivot member which has the axle contact area can be curved in both a horizontal and a vertical direction. In various embodiments, the nonplanar surface can be made of or approximate a number of planar surfaces, or it can be continually curved. In some embodiments, pivot member 40 is not included for the integral truck to function in the intended way. In the absence of a fixed pivoting axis 43 , the axle will float on the springs 44 R and 44 L, providing a compliant suspension. In some embodiments, the pivot member can be a pin or a rod. In some embodiments, the pivot member can contact the exterior of the axle, such as at a round, flat, grooved, dimpled, indented, etc. portion of the axle or covering; in some embodiments, the pivot member can contact the interior of the axle, such as in a hole; and in some embodiments, the pivot member can contact the interior and exterior of the axle. In some embodiments, the axle 36 can include a covering over at least a portion of its surface, and the pivot member can contact the exterior or interior of the covering portion of the axle 36 . The pivot member can be a pin protruding from the center of the axle 36 at a right angle or another angle to the axle, said pin can protrude into a hole or cavity formed in a middle portion of the inclined axle bearing surface 38 . In some embodiments, different locations for the pin in the axle, the axle bearing surface, or both, for various reasons including to modify the ride characteristics of the conveyance, to facilitate construction or assembly, etc. In some embodiments, more than one pin can be utilized. In some embodiments, the bearing surface can be a continuous or a discontinuous surface. Suitable discontinuous surfaces include those made up of a number of separated surfaces or surfaces interconnected with a different material or a recessed material. Individual surfaces can be made of like or unlike materials. Individual surfaces can be flat, curved, circular, rectangular, regular, a regular, interlocking, non-interlocking, or any other suitable shape as desired. In some embodiments, the surface of the pivot member can be a continuous or discontinuous surface as well. In some embodiments a continuous bearing surface can be utilized with a pivot member having a discontinuous surface, or a discontinuous bearing surface can be utilized with a pivot member having a continuous surface, or both the bearing surface and the surface of the pivot member can be either continuous or discontinuous. In some embodiments, the pivot member or the bearing surface can be made up of a series of individual parts, such as in the form of ridges protruding from a support material or a separate part. Examples of discontinuous faces on the axle bearing surface and the pivot member surface are shown in FIGS. 19B , 20 A and 22 . In FIG. 20A for example, the axle bearing surfaces and pivot members surfaces are formed by an opened cell network performed by a plurality of struts, which are chosen of a spacing and thickness of material sufficient to withstand relevant forces from the axle. FIGS. 20A and 22 show an extended curved surface 122 arranged symmetrically across the longitudinal access of the conveyance. As shown, the pivot surface extends a substantial proportion of the width of the device in this area. In these figures remaining in that area is shown in recessed portions 124 and 125 . In some embodiments, the device may have one or more handles attached to or formed therein. Such handles can aid in riding the device or performing maneuvers and/or can be used to attach pulling cords and the like. Preferably the forward end or front end of the device has an handle. The rear of the device may also have a handle, for example as is shown in FIGS. 19A , 19 B, ( 120 , 121 ). In some embodiments, the pivot member can be disposed at an angle to the bearing surface, such as where the bearing surface and the surface of the pivot member intersect at the vertex 106 of an angle, as shown in FIG. 20A . In one embodiment, the pivot member can be disposed at an angle to the bearing surface with a gap between the surface of the pivot member and the bearing surface, such as where a continuation of the pivot member surface or the bearing surface could intersect with the other. In one embodiment, additional material can be interposed between the surface of the pivot member and the bearing surface, such as in the vicinity of the vertex of the angle. In some embodiments, the entire pivot member and the bearing surface can be separated such as by a gap or by intervening material. In some embodiments, as shown in FIG. 21 , the surface of the pivot member can be located such that a ray 101 originating from a contact zone 107 of the axle 36 with the surface of the pivot member 90 , normal to the axle and passing through the axle centerline 105 (“normal ray”) has a component 102 substantially parallel to the direction of travel 104 . In some embodiments, the surface of the pivot member can oppose the bearing surface, such as where a normal ray intersects the bearing surface or intersects with a plane that would be an extension of an edge of the bearing surface or a plane that includes it is parallel to a portion of the bearing surface that contacts the axle. In FIG. 15 , an overmolded axle block 92 is depicted. This may be a simple rectangular prism used in conjunction with the springs and/or pivots described previously, or may incorporate an extended pivot member section as illustrated, including optional curved and non-curved portions. The axle block 92 can be integral to the axle, or assembled to the axle. The mode of action of the axle support unit with an inclined axle bearing support surface 38 is in some embodiments will now be described. In FIG. 4 , when a downward force 52 is imposed on the left front side of the platform, or a compressive force between the axle support unit and the axle, the left front wheel 34 L is forced rearward or forward, depending for example on the location and orientation of the inclined bearing surface 38 and the pivot member 40 or 80 or 90 , by the inclined axle bearing surface 38 that supports it, inducing a turn to the left or right, provided that the platform or board leans into the turn. As the downward or compressive force 52 is imposed, at least a portion of the axle 36 slides across the inclined axle bearing surface 38 and the axle pivots, a component of the rotation lying in a plane substantially parallel to the top surface of the foot support platform 32 . In some embodiments, an outboard portion of the axle 36 slides across the bearing surface. If the axle includes a covering, spacer, etc. which contacts the axle bearing surface 38 , the covering, spacer, etc. portion of the axle 36 will slide across the surface. The sliding motion can be described in some embodiments as an arc, a displacement, or a combination of an arc and a displacement. Hence the design can be set-up so the rider leans left and turns left, into his lean, facilitating a balancing and turning action similar to that of a conventional skateboard, or in some applications, he turns right when he leans left. In the drawings, the conveyance is represented as a three-wheeled device, with a single rear wheel, but it should be understood that the single rear wheel may be replaced by a second integral truck and wheel assembly which is the minor image of the front truck and wheel assembly about a plane whose normal vector is the long axis of the conveyance 82 . In some three-wheeled embodiments, the fender 48 , can serve as a platform for the rider to rest his pushing foot, when coasting down a hill for example. A four-wheeled device, can include a cantilevered beam, fixed with respect to the main riding platform and preferably molded as part of a foot support platform, protruding from the rear end of the foot support platform, behind the rider's heel, and can include such features as fender and brakes as desired. The rear fender 48 can be made to be flexible or compliant, so that with heavier pressure from the foot resting on it, it could serve as a brake by deforming and engaging with the rotating rear wheel 46 below it. An integral leaf spring could be formed in the elastic material of the fender to facilitate this motion. The entire fender could also be made to pivot around an axis parallel to but not coaxial with the rear axle, where resistance to pivoting would be supplied by a spring. In various embodiments, the fender would not engage the wheel with moderate pressure exerted by resting the rider's pushing foot during coasting, but would engage with heavier pressure applied by transferring weight to the pushing foot if the user wished to stop the conveyance. Resistance to the fender pivoting action could be applied by a torsion spring, or a rigid lever arm combined with a tension or compression spring. The compression springs 44 R and 44 L can be attached to the platform with an adhesive or adhesive tape, or can be retained in a slot or cavity molded or cut in the spring bearing surface 39 . The product may be provided with a set of springs of differing stiffuesses to accommodate riders of various weights. Such a set of springs may be color coded. Although the springs 44 R and 44 L in the various figures provided are depicted in a somewhat central location for clarity, in practice it would be advantageous to position them as close to the wheels 34 R and 34 L as possible, to minimize the bending moment on the axle 36 . Another method of providing variable resistance to turning can include placing the springs 44 R and 44 L in a slot formed in the spring bearing surface 39 , where the position of the springs along the axle 36 could be adjusted. If the springs 44 R and 44 L are moved towards the center of the spring bearing surface 39 (and closer to each other) the resistance to pivoting of the axle can be reduced, which might be desirable for a lighter rider. With the springs in wider positions (farther from each other), the resistance to pivoting of the axle can be increased, which might be desirable for a heavier rider. Higher resistance to pivoting can occur with the springs located directly adjacent to the wheels, 34 R and 34 L. However, a tradeoff can also be made with softer springs in a wider position to achieve similar or less resistance to pivoting as stronger springs in a narrower position. In this embodiment, it can be advantageous to have the springs seated in a slot formed in the spring bearing surface 39 , with sufficient friction to look them in place when the conveyance was in use, but sufficient clearance so that they could be shifted along said slot to adjust the turning resistance of the conveyance. Frequently in this description the full-width or partial-width inclined axle bearing surface 38 is described as formed as an integral part of the platform, however, it should be understood that even where the inclined axle bearing surface 38 is shown as full-width in all the drawings, the inclined bearing surface 38 can be narrower and can provide support to the axle 36 near the wheels, away from the wheels, or both near and away from the wheel, and the support for the axle can be continuous, or at discrete points over at least a portion of the length of the axle. Variations of these aspects of the design can provide additional benefits such as reducing the bending moment experienced by the axle over that experienced by axles in other designs. In some embodiments, the reduced bending moment of the axle 36 means that the axle can be of smaller diameter and lower cost and weight. In some embodiments, the inclined axle bearing surface 38 maybe cut away or not in contact with the axle 36 in the central part of the platform 32 , near the pivot member 40 or 80 or 90 . Further, the inclined axle bearing surface 38 is at various points shown and described as part of a unitary body, such as can be produced by injection molding the platform 32 and inclined axle bearing surface 38 in one shot from a suitable thermoplastic. However, it should be readily apparent that the inclined axle bearing surface 38 could be molded or formed from a different material and snapped or fastened to the main platform body 32 . For example, it may be desirable to have an inserted surface with low friction and/or high wear resistance. In addition, the body and/or platform can be made from multiple pieces and then assembled. It should be noted, however, that a unitary construction can have advantages of a higher resistance to bending than some other designs, and thus may be preferred in some cases, and can result in reduced the weight and cost, including fabrication costs of the conveyance while maintaining an adequate bending stiffness of the platform 32 . In one embodiment, leaf springs are integrally formed as part of the spring bearing surface 39 of the foot support platform 32 and replace springs 44 R and 44 L. This embodiment is dependent on the body of the unitary platform being constructed of a resilient, elastic material. In some embodiments, the platform can be attached to the rider's shoe such as with a flexible or semi-rigid strap 68 fastened to the body 32 somewhere between the front and rear wheels. Such a strap, lace or other attachment may be quickly fastened to itself with, for example, Velcro® on top of the rider's shoe, or otherwise. In some embodiments, a Velcro® patch or other releasable engagement means could be added to the sole of the rider's shoe to engage with its counterpart attached to the platform of the conveyance. In some embodiments, a special set of shoes with slots molded in their soles to engage a tab to be molded in the upper surface of the conveyance, or to provide engagement for a binding system such as is used for bicycles, skis, snowboards, etc. can be used. In some embodiments, various other attachment systems or devices can be used, such as those used for attaching a roller skate, ski, snowboard, water ski, or other conveyance to a shoe, boot, or foot may also be employed. A deadman's brake assembly is depicted in FIG. 6 , where the rear fender 48 has been cut-away for clarity. The torsion spring 60 causes the angled lever 58 to engage the rear wheel and slow or stop the conveyance when the rider falls or steps off. The point of contact of the angled lever with the wheel is designated the “friction pad.” When the rider is riding the conveyance, his or her heel can engage the front part of the angled lever 58 forcing it into a depression 61 formed in the platform 32 and disengaging it from the rear wheel 46 , allowing the conveyance to roll unimpeded. The angled lever 58 can be supported by an axle 62 . The torsion spring 60 could be replaced with a compression spring (coil, rubber, etc.) located, for example, between the horizontal portion of the angled lever 58 and the floor of the depression 61 in the platform body 32 . In FIG. 8 , an embodiment of a deadman's brake assembly in which the angled lever is replaced by a tab that is formed as an integral part of the platform 32 is depicted. This embodiment has the body of the foot support platform 32 being constructed of a resilient, elastic material that can deform elastically when the user's foot depresses the tab. In another embodiment, a material such as polypropylene, into which a living hinge can be molded could be used, with an optional secondary spring to provide at least a portion of the force that the deadman's brake applies to the wheel. The axle 36 , can be prevented from sliding side to side relative to the longitudinal axis 82 of the platform 32 . This may be accomplished in various ways. In one embodiment, a cylindrical pin is welded to the axle or screwed into a cavity in the axle such that the central axis of the cylindrical pin passes through a central area of the axle. Said pin protrudes from the axle, and fits in a hole formed in a corresponding portion of the inclined axle bearing surface 38 . In some embodiments, the pin can function as a pivot member 40 . In another embodiment, the axle can be positioned by two disks 64 L and 64 R fastened at a fixed axial position to the axle 36 between the wheels 34 L arid 34 R and the outermost edges of the inclined axle bearing surface 38 of the platform 32 , as depicted in FIG. 7 . When the rider is riding the conveyance and exerting a downward force on the platform, the axle can be held in its vertical location relative to the foot support platform 32 and the axle bearing surface 38 by the balance of forces; since the ground exerts an upward force on the axle through the wheels. In some embodiments it can also desirable to provide a means of retaining the axle in position relative to the inclined axle bearing surface 38 if the rider picks the conveyance off the ground. For example, in FIG. 3 , a rod 45 has been inserted in a hole drilled in the pivot member 40 . This rod 45 wraps underneath the axle 36 , and can, for example, hold the axle securely against the inclined axle bearing surface 38 or otherwise prevent the axle from falling off. In another example, as shown in FIG. 16 , a pin 94 passes through the axle 36 and a slot or hole 91 in the axle bearing surface 38 . Preferably, the slot will allow sufficient travel for the axle to move and turn in response to the efforts made by a rider to turn. A retention means could also be built into the compression springs 44 R and 44 L by having a protuberance in the springs hook around the underside of the axle. Alternatively, a band of the material of which the unitary platform 32 is constructed (not depicted) passing underneath the axle may be molded as an integral part of the unitary platform. It should be noted that the various retention devices shown can be used with the various pivot members and axle bearing surfaces described herein. In some embodiments, the axle 36 can be a solid or unitary cylinder. In some embodiments, the axle 36 can be non-solid, multi-piece, or a shape other than a cylinder. The axle can have any other cross-sectional shape, including square, rectangular, variable, etc., and the axle can be hollow, multi-part, a single piece, etc. In some embodiments, the axle can have one or more holes, cavities, indentations, extensions, protrusions or other shape features, such as for receiving a spring, a pin, an axle retention device, etc. or for other purpose, such as to contact a bearing surface or a pivot member. In some embodiments, a second material, such as a polymer or aluminum composition can be molded over the axle to form an axle block 92 in the region between the wheels 34 R and 34 L. Alternatively, the axle block may be a formed from a single material, with cylindrical axle segments formed from a second material or the same material protruding from either end. In either case, the axle block 92 could include a flat plane to sit flush on the inclined axle bearing surface 38 , or another shaped surface that can interface with a similar or matched surface of the axle bearing surface 38 , which in some embodiments can reduce wear on these surfaces. In some embodiments various features needed to retain the axle 36 and wheels laterally and vertically could be readily molded into the axle block. For example, a central locating pin transverse to the axle, or locating washers 64 L (and 64 R, not depicted) may be molded as part of the axle block. In some embodiments, the axle could be fitted with bearings or bushings near the wheels so that said bearings or bushings provide rolling contact with the inclined axle bearing surface 38 , in order to, for example, modify the steering response or reduce the wear and, friction associated with sliding of the axle 38 on the inclined axle bearing surface 38 . In some embodiments, sliding contact can be reduced or eliminated. Bearings can be used to support the axle at a more central position, or only at a position just inside the wheels, or additional bearings or wider or multi-race bearings can be use to provide support along more of the axle's width. In FIG. 15 , an overmolded axle block 92 is depicted. In some embodiments, this can be a simple rectangular prism used in conjunction with the springs and/or pivots described previously, or may incorporate an extended pivot member section as illustrated, including optional curved and non-curved portions. In some embodiments, a narrow surface similar to a pivot member 40 can be incorporated into an axle block or a broad surface similar to an extended pivot member 80 or a curved extended pivot member 90 . The axle block 92 can be integral to the axle, or assembled to the axle. In some embodiments, a substantial portion of a conveyance can be molded out of a plastic material or a thermoplastic fiber reinforced thermoplastic composite as a single piece or as a small number of pieces for assembly, such as, the foot support platform 32 , the rear fender 48 , the inclined axle bearing surface 38 , the pivot member 4 G, any special means for retaining the compression springs 44 L and 44 R, the deadman's brake 60 , and other features could all be molded in a single injection molding operation. In some embodiments, all or a portion of the parts can be produced separately. In some embodiments, some of these parts can be left out, for example the rear fender 48 , the deadman's brake 60 , or other features or combinations of features as desired. Such molding can result in reduces cost and/or reduced weight of the conveyance. In some embodiments, features can be designed to simultaneously increase the stiffness and strength of the conveyance, while reducing the cost and amount of material, used. In FIG. 5 , examples of molded-in cavities 54 are depicted. Variations of the design of molded-in cavities are possible, such as are used in the production of various items including those found in the lower leg assembly of a pedestal office chair, where said assembly was molded from a thermoplastic. In some embodiments, an extended flanges 56 on the central portion of the platform 32 in FIG. 5 can be incorporated, for example, to increase the bending stiffness of the foot support platform 32 about an-axis parallel to the rear axle. In some embodiments, portions of the device can be made from wood, metal, or some other appropriate material having appropriate characteristics of weight, stiffness and durability. In some embodiments, all or portions of the device can be machined, such as out of plastic, fiber reinforced plastic, metal, or wood. In some embodiments, parts can be cast or stamped out of metal. Suitable metal for construction of the device include steels and alloys of steel, nickel and/or chromium containing materials, aluminum, titanium, copper, brass, bronze, etc. In some embodiments, a lighter material can be utilized for a portion of the device and a harder or more durable material for another portion. Elastomers can be utilized for portions of the device as well. In some embodiments, a gravity or centrifugal force can be utilized to provide assistance in recovering the conveyance from a turn. A gravity or centrifugal force can be used in conjunction with springs, such as coil, leaf, elastomer, etc, or they can be used without springs. The recovery from turning can be induced without springs by, for example, ensuring that as the axle pivoted, the central portion of the foot support platform 32 was forced away from the axle (See FIG. 4 ). This case, the central portion of the foot support platform 32 would be forced to increase in altitude as the conveyance was tilted and the axle pivoted. (In this document, altitude is defined as the distance from the road surface, or a plane having an analogous relationship to the wheels as a road surface, along an axis normal to the road surface or plane.) The central portion of the foot support platform 32 would normally be at a lower altitude from the road surface or analogous plane, and its altitude would increase if the axle pivoted in either direction. A similar position restoring force can be provided by the centrifugal force experienced while turning the conveyance. This linkage between the pivoting action, and an altitude increase of the foot support platform is referred herein as a “gravity spring”, regardless of how it is accomplished. A gravity spring provides a restorative force to return the axle to its normal position substantially perpendicular to the centerline of the skateboard, and the skateboard travels in a substantially straight line unless the rider applies a torque about the centerline by leaning. Benefits with a gravity spring can include in some embodiments self-adjustment of a turn restorative force to the weight of a rider or load, reduced number of parts for construction of the conveyance, and elimination of parts subject to breakage or wear and requiring repair or replacement. First, the turn restorative force tending to return the front axle to its normal position relative to the long axis of the conveyance 82 with a gravity spring can be related to the weight of the user, potentially rendering one set of parts suitable for riders having a range of weights. Second, the need for springs is eliminated, reducing the number of parts used in manufacturing and assembling the conveyance, and eliminating springs or bushings that can break or wear out. In one embodiment, a gravity spring is made by using an elongated pivot member 80 or 90 rather than a single pivot point, as depicted in FIGS. 11 , 12 , 14 , 16 , 17 , 18 A and 18 B. In this method, the inclined axle bearing surface 38 can be planar, as in previously described embodiments, or otherwise, and the pivot member 80 or 90 is shaped so that as a compressive force is applied between the axle bearing surface 38 and the axle 36 , such as when the rider leans or shifts his weight, the pivot point (or point of contact between the axle 38 and the pivot member 80 or 90 ) shifts towards the wheel closest to the compressive force. This shift causes the axle to rotate in a plane parallel to the travel surface (i.e. turn). In some embodiments, the rotation of the axle can cause a turn in the direction of the lean or shift in weight as depicted in FIG. 12 . Since the pivot point is closer to the inside wheel (for this discussion, a system of lean left/turn left is assumed, but in some other embodiments, as with other parts of this description, this assumption can be reversed, as understood by one having skill in the art), as the axle 36 pivots, the rearward motion of the inside wheel is less than the forward motion of the outside wheel. Since the axle 36 is in contact with the inclined axle bearing surface 38 , the inside wheel moves towards the top surface 51 of the foot support platform 32 by an amount less than the distance that the outside wheel moves away from the top surface 51 of the-foot support platform 32 . The net result is that the distance between the central portion of the axle 36 and the nearest point on the top surface of the foot support platform 51 is increased when the axle 36 pivots, elevating the foot support platform and the rider. The center of the axle in the gravity spring, shifts down the axle bearing plane, moving it farther away from the top surface of the board, increasing the altitude of the deck, and providing a restorative force. The rider or load is closest to the road when the front axle 36 is perpendicular to the long axis of the conveyance 82 , and at least a portion of his foot or the load is elevated whenever the conveyance tilts and the axle pivots in either direction. This contributes to the desired gravity spring effect that induces the conveyance to level out so that it travels in a substantially straight line unless the rider supplies a torque around the long axis 82 of the conveyance. The magnitude of the centering force imposed by the gravity spring can depend on the width and shape of the pivot member, the angle of the inclined axle bearing surface, as well as other factors. For simplicity, a simple rectangular extended pivot member 80 is shown in FIGS. 11-12 , but this block could be rounded off, as long as pivoting of the axle 36 away from its position perpendicular to the long axis of the conveyance 82 produces a shift in the central portion of the foot support platform 32 away from the axle 36 . A suitable curved extended pivot member is depicted in FIG. 14 . Additional embodiments of curved extended pivot members are provided in FIGS. 16 , 17 , 18 A and 18 B. In some embodiments, an extended pivot member 80 or 90 can be attached to the axle 36 instead of molding it as part of, or fixing it rigidly to, a stationary part such as a portion of the foot support platform 32 or the spring bearing surface 39 . In some such embodiments, the spring bearing surface 39 or other portion that the axle block 92 interfaces with could he planar, and an axle block could be overmolded on the axle as described previously. The extended pivot member could be molded into the central region of the axle block 92 , and bear against the spring bearing surface 39 . Such an arrangement is depicted in FIG. 15 . Another embodiment of a gravity spring includes constructing the inclined axle bearing surface 38 to have a non-planar bearing surface as depicted in FIG. 13 . In this embodiment, the inclined axle bearing surface is curved or segmented ( 88 A and 88 B), and the slope of the rear part of the surface 88 B is less than the slope of the front part of the surface 88 A, where the slope is measured by the angle between the plane and the top surface 51 of the foot support platform 32 , however in some embodiments, the slopes of these two portions can be reversed, with the slope of the rear part of the surface 88 B being greater than the slope of the front part of the surface 88 A. In addition, other embodiments can have a greater number of differently sloped surfaces on the inclined axle bearing surface 38 , or a curved surface or a variably curved surface where the radius of curvature changes along the surface. As the axle is induced to pivot by tilting the platform about its long axis 82 , the inside wheel moves closer to the top surface 51 of the foot support platform 32 along the lesser slope of the rear part of the inclined axle bearing surface 88 B. (Here the terms “inside” and “outside” refer to the conventional definitions of the inside and outside of the turn.) Meanwhile the outside wheel moves farther from the top-surface 51 of the foot-support platform 32 along the greater slope of the forward part of the inclined axle bearing surface 88 A. Because of this, the outside wheel moves away from the top surface 51 by more than the inside wheel moves towards said top surface 51 , and the altitude of the center of the top surface 51 of the foot support platform increases. The inclined axle bearing surface can frequently be shaped so that the altitude of the center of the top surface of the foot support platform is lowest when the axle 36 is perpendicular to the long axis of the conveyance 82 or the altitude of the center of mass of the foot support platform 32 is lowest when the axle 36 is in its normal position, not influenced by an induced tilt of the foot support platform 32 . This creates a gravity-spring that causes the conveyance-to travel in a substantially straight line (or the conveyance's normal direction of travel) if it is not deliberately tilted around its long axis 82 through the application of torque by the rider. In some embodiments, the inclined axle bearing surface 88 can have a complex curvature designed to facilitate keeping most of the axle in contact with the inclined axle bearing surface 88 , regardless of the degree of pivot, which can have a larger slope towards the front of the conveyance, and a lesser slope towards the rear with a gravity spring unit mounted in the front portion of the conveyance and a larger slope towards the rear of the conveyance and a lesser slope towards the front with a gravity spring unit mounted in the rear portion of the conveyance. In some embodiments, a gravity-spring unit can be combined with a set of compression springs 44 R and 44 to create a combined force to restore the conveyance to substantially straight fine motion (or other normal travel direction as designed into the unit). The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents. All references cited herein, including but not limited to published and unpublished applications, patents, and literature references, and also including but not limited to the references listed in the Appendix, are incorporated herein by reference in their entirety and are hereby made a part of this specification. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material. The term “comprising” as used herein is synonymous with “including,” “containing,” or “characterized by,” and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. All numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth herein are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of any claims in any application claiming priority to the present application, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches. The above description discloses several methods and materials of the present invention. This invention is susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention.

Devices and methods of transport are disclosed. Various embodiments include structural aspects related to steering and changing the direction of conveyances including features which utilize leaning or shifting of weight as part of turning.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. NO. 11/148,543 to Moffat et al., filed Jun. 8, 2005, which is a continuation in part of U.S. patent application Ser. No. 10/656,840 to Moffat et al., filed Sep. 5, 2003. BACKGROUND [0002] 1. Field of the Invention [0003] This invention relates to the coating of substrates, and in particular to an apparatus and process for the efficient coating of substrates using chemical vapor reaction and gas plasma cleaning. [0004] 2. Description of the Related Art [0005] The application of coatings onto substrates and other workpieces is required as a process step in many industrial fields. An example of such a process is the coating of a silicon wafer with a layer of Hexamethyldisalizane (HMDS). This coating process is used to promote the adhesion of organic layers such as photoresist to the inorganic silicon wafer. The HMDS molecule has the ability to adhere to the silicon wafer and also to be adhered to by an organic additional layer. For example, silicon wafers would be baked for 30 minutes in a 150 C oven for 30 minutes to dehydrate them. The silicon wafers would then be sprayed with HMDS. The excess HMDS would then be spun off of the silicon wafer. A typical process of this type would result in a HMDS monolayer on the surface of the silicon wafer. [0006] A problem encountered with the above mentioned process was that if the silicon wafer was not sufficiently dry prior to the application of HMDS, then residual moisture would interfere with the reaction of the HMDS to the silicon wafer. This would result in variations in the HMDS layer reaction and then could lead to voids in the subsequently applied next layer. Another problem with a process of this type is that HMDS would rapidly deteriorate when exposed to air and moisture, and thus such a process required a large amount of HMDS to provide a small amount of reaction. [0007] Because of the problems relating to variations in the HMDS monolayer, processes for the coating of substrates with HMDS evolved. Later processes more thoroughly dehydrated the silicon wafer substrate prior to the application of HMDS, and limited the HMDS from much, if any, exposure to air and moisture. An example of such a process would be as follows. Silicon wafers would be placed in a vacuum chamber and cycled back and forth between vacuum and preheated hot dry nitrogen in order to dehydrate the silicon wafer. For example, the silicon wafer would be exposed to a vacuum of 10 Ton for 2 minutes. At this pressure water boils at about 11 C. The vacuum chamber would then be flooded with preheated nitrogen at 150 C. This part of the process would heat the surface of the silicon wafer so that the high temperature of the wafer would assist in the dehydration process as vacuum was once again applied. After 3 complete cycles, a vacuum of 1 Torr would be applied to complete the dehydration process. [0008] The next step in such a process is to open a valve between the vacuum chamber and a canister of HMDS. At room temperature the HMDS boils at approximately 14 Ton and thus the chamber is flooded with 14 Torr of HMDS vapor. In this process the HMDS is not exposed to air or moisture and the silicon wafer is significantly dryer prior to being coated. [0009] Some coating processes based on the above mentioned type of process require a higher pressure. The HMDS is preheated to create a higher vapor pressure. Typical figures are preheating of the HMDS to 100 C to produce up to 400 Ton pressure or HMDS vapor while limiting the pressure in the process oven at 300 Torr to avoid condensation of the HMDS. [0010] Processes involving the preheating of the deposition chemicals have the drawback that if the deposition chemicals degrade with exposure to heat then the bulk preheating of these chemicals may result in the loss of the unused residual chemical. These chemicals are often very expensive. Also, many of these chemicals are hazardous materials. The less of these chemicals actually being used in the process at any time reduces the potential risk for processing facilities. [0011] The coating of substrates for biotech applications may require sufficiently dehydrated substrates and insertion into the process chamber of one or more deposition chemicals which have been preheated and/or vaporized prior to insertion. Some coatings for biotech applications are quite expensive. Some coatings are difficult to vaporize and vaporization requires a combination of low pressure and high temperature. Without reduced pressure, the temperature required for vaporization may be too high to retain stability of the chemical to be vaporized. Biotech applications may require silane deposition onto glass and/or other substrates as a bridge to organic molecules. Among the silanes used are amino silanes, epoxy silanes, and mercapto silanes. These silanes are used in the adhesion layer between glass substrates and oligonucleotides. Oligonucleotides are a short DNA monomer. Substrates are coated with a monolayer of silane as a bridge between the inorganic substrate and the organic oligonucleotide. A silane coated substrate with an oligonucleotide layer is now a standard tool used in biotech test regimens. One area where this oligonucleotide layer is used is in the formation of DNA microarrays. A uniform and consistent silane layer leads to a more uniform and consistent top surface of the oligonucleotide layer, which in turn leads to more useful test results. [0012] What is called for is a process and apparatus which withdraws deposition chemicals from a bulk storage container and then preheats and/or vaporizes this portion separately prior to delivery into the process chamber, allowing for the introduction of deposition chemicals at high temperatures and/or vapor pressures into a process chamber, without requiring preheating of bulk amounts of the deposition chemicals. What is also called for is an apparatus which is able to plasma clean substrates in the chamber into which the vaporized chemicals will be delivered, and an apparatus which can clean itself after such production runs using plasma. [0013] Substrates coated with such a process have reduced contamination, have more consistent monolayers with better bonds to the substrate, allowing for a more consistent oligonucleotide layer. This consistent substrate, used in DNA microarray tests, leads to more accurate test results SUMMARY [0014] A process for the coating of substrates comprising insertion of a substrate into a process oven, dehydration of the substrate, plasma cleaning of the substrate, withdrawal of a metered amount of one or more chemicals from one or more chemical reservoirs, vaporizing the withdrawn chemicals in one or more vapor chambers, and transfer of the vaporized chemicals into a process oven, thereby coating the substrate. An apparatus for the coating of substrates comprising a process oven, a gas plasma subsystem, a metered chemical withdrawal subsystem, a vacuum subsystem, and a vaporization subsystem. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is a pictorial representation of portions of one embodiment of the invention highlighting the chemical withdrawal, infuse, and vaporization subsystems. [0016] FIG. 2 is a pictorial representation of portions of one embodiment of the invention highlighting the chemical withdrawal and infuse subsystems. [0017] FIG. 3 is a representational piping schematic of one embodiment of the present invention. [0018] FIG. 4 is a pictorial representation of portions of one embodiment of the present invention highlighting the vacuum and gas delivery subsystems. [0019] FIG. 5 is a front isometric view of one embodiment of the present invention. [0020] FIG. 6 is a rear isometric view of one embodiment of the present invention. [0021] FIG. 7 is a partial cutaway side view of one embodiment of the present invention. [0022] FIG. 8 is a blown up section of the partial side view of FIG. 7 . [0023] FIG. 9 is a side view of one embodiment of the present invention. [0024] FIG. 10 is a rear view of one embodiment of the present invention. [0025] FIG. 11 is a top view of one embodiment of the present invention. [0026] FIG. 12 is a rear view of one embodiment of the present invention. [0027] FIG. 13 is a partial cutaway view of one embodiment of the present invention. [0028] FIG. 14 is a view of the process oven interior according to one embodiment of the present invention. [0029] FIG. 15 is a view of the process oven interior according to one embodiment of the present invention. [0030] FIG. 16 is a view of the process oven interior according to one embodiment of the present invention. [0031] FIG. 17 is a view of the process oven with its door open according to some embodiments of the present invention. [0032] FIG. 18 is a partial view of one embodiment of the present invention displaying the metering pumps. [0033] FIG. 19 is a partial view of one embodiment of the present invention displaying the metering pumps. DETAILED DESCRIPTION [0034] In one embodiment of the present invention, as seen in FIG. 1 , chemical vapor deposition apparatus 101 has a fluid input portion 102 , a vaporization portion 103 , and a process oven 104 . Process oven 104 may be controlled with regard to both temperature and pressure. Fluid reservoirs 106 , 107 provide the chemicals for the fluid input portion 102 . Fluid reservoirs 106 , 107 , may be manufacturer's source bottles in some embodiments. Fluid reservoirs may contain the same fluid, allowing for the easy replacement of one reservoir if empty without disruption of the deposition process, or may contain separate chemicals. In some applications, water may be used as one of the chemicals in order to facilitate some rehydration of the substrate. [0035] Chemicals in the fluid reservoirs 106 , 107 , are withdrawn into fluid input portion 102 by syringe pumps 108 , 109 . Although syringe pumps are used in this embodiment, other methods of withdrawal may be used, including peristaltic pumps and other appropriate methods. Chemical withdraw valves 116 , 117 , provide isolation between fluid reservoirs 106 , 107 , and syringe pumps 108 , 109 . Chemical withdraw valves 116 , 117 , are opened prior to withdrawal of chemicals from fluid reservoirs 106 , 107 . [0036] Chemical infusion valves 113 , 114 provide isolation between syringe pumps 108 , 109 , and the vapor chamber 110 . The vapor chamber 110 is surrounded by vapor chamber heater 118 . Although the vapor chamber heater is external to the vapor chamber in this embodiment, the vapor chamber heater may be internal to the vapor chamber or integral to the vapor chamber. The vapor chamber heater 110 may be P/N MBH00233 manufactured by Tempco, of Wood Dale, Ill., or other suitable heater. The vapor chamber 110 is fluidically coupled to process oven 104 by heated vapor line 111 . The vapor chamber 110 may be isolated from process oven 104 by the operation of heated vapor valve 115 . An example of such a heated vapor valve is valve P/N SS-8BK-VV-1C by Swagelok of Sunnyvale, Calif., with heater P/N 030630-41 by Nor-Cal Products of Yreka, Calif. The vapor chamber manometer 112 monitors the pressure inside vapor chamber 110 . The process oven 104 may contain one or more trays 105 . [0037] In one embodiment of the present invention, as seen in FIG. 2 , fluid input portion 102 routes chemicals from the fluid reservoir 106 through a delivery pipe 203 to the chemical withdraw valve 116 . An example of such a chemical withdraw valve 116 is P/N 6LVV-DP11811-C manufactured by Swagelok of Sunnyvale, Calif. A fluidic coupler 211 is inserted into fluid reservoir 106 to allow fluid withdrawal from the fluid reservoir 106 . In this embodiment, the fluid reservoirs 106 , 107 , are chemical source bottles. The fluidic coupler 211 also allows fluid such as dry nitrogen gas from pipe 202 to be inserted into the chemical reservoir 106 to fill the volume voided by the removal of chemical from the chemical reservoir 106 . Exposure of the chemical to air and/or moisture is thus minimized. The syringe pump 206 may withdraw chemicals from fluid reservoir 106 when the chemical withdraw valve 116 is opened. An example of the syringe pump 206 is P/N 981948 manufactured by Harvard Apparatus, of Holliston, Mass. Actuation of the syringe pump mechanism 207 withdraws chemicals from the fluid reservoir 106 by partially or fully withdrawing the syringe plunger 208 from the syringe body 209 . The amount of chemical withdrawn may be pre-determined, and also may be pre-determined with accuracy. The chemical is routed from the fluid reservoir 106 , through the fluidic coupler 211 and the delivery pipe 203 to the chemical withdraw valve 116 , through a pipe 214 and a T-coupler 205 to the syringe body 209 in this embodiment. In general, fluidic coupling can be referring to liquid or gas coupling in this embodiment. [0038] After withdrawal of chemicals into the syringe body 209 , the chemical withdraw valve 116 may be closed to isolate the delivery pipe 203 . The chemical infusion valve 113 may then be opened to link the syringe body 209 to the vapor chamber 110 . An example of such a chemical infusion valve 113 is P/N 6LVV-DP11811-C manufactured by Swagelok of Sunnyvale, Calif. The syringe pump mechanism 207 may then re-insert the syringe plunger 208 partially or fully into the syringe body 209 , forcing the chemical within the syringe body 209 through the T-coupler 205 and then through pipe 210 . With the chemical infusion valve 113 open, the chemical then may enter the vapor chamber 110 via pipe 215 . Pressure within the vapor chamber 110 is monitored with the vapor chamber manometer 112 . An example of such a manometer is a 0-100 Ton heated capacitance manometer P/N 631A12TBFP manufactured by MKS of Andover, Md. [0039] The fluid reservoir 106 is secured with a spring clamp 212 within a source bottle tray 213 . The source bottle tray 213 may also act as a spill containment vessel. [0040] In some embodiments of the present invention, the fluid input portion 102 delivers the desired amount of chemical in another way. The chemicals in the fluid reservoirs are withdrawn in a pre-determined amount using a metering pump. For example, the metering pump may withdraw and deliver 2 milliliters per stroke. To deliver a specific quantity of a chemical, the metering pump would be pumped repeatedly until the desired quantity had been delivered. In some embodiments using metering pumps, the chemical withdraw valve and the chemical infusion valve are not necessary. The metering pump itself acts to isolate the fluid reservoir from the vapor chamber. Such embodiments allow for the delivery of the chemical from the fluid reservoir with less required hardware. [0041] FIGS. 18 and 19 are partial cutaway views of an embodiment using metering pumps. The metering pumps 1801 are fluidically coupled to the vapor chamber. Chemical reservoirs 1802 , 1803 are the source of supply of the liquid which the metering pumps 1801 pump into the vapor chamber (some piping is omitted in the Figures). [0042] One of skill in the art will understand that the fluid input portion may have other embodiments that may use the above described elements in different types of combinations, or may use different typed of elements. [0043] In one embodiment of the present invention, as seen in FIG. 3 , piping and other hardware is arranged as illustrated in the piping schematic 401 . Vacuum and gas portion 402 illustrates the portion of the apparatus with inputs for gas and the provision of vacuum. In one embodiment of the present invention, a high pressure gas inlet 403 connects to 80-100 psig nitrogen, an inlet 404 connects to 5-15 psig of a process gas, and an inlet 405 connects to 15-40 psig nitrogen. A vacuum inlet 406 provides vacuum to the system. [0044] The high pressure gas inlet 403 provides gas via a line 464 to the chemical reservoirs 502 , 503 , and also provides the pressure to actuate valves 463 and valves 480 - 484 . Solenoids 421 - 427 are directed by a logic controller at I/O locations 440 - 445 to actuate valves 480 - 485 using solenoids 421 - 427 . The gas from the high pressure gas inlet 403 is reduced in pressure to 4 psig by a pressure reducer 460 to be fed to the chemical reservoirs. [0045] The solenoid acutated valves 430 , 431 are triggered by directions from a logic controller at I/O interfaces 454 , 455 to allow for purging of the chemical source bottle feed line 490 . [0046] When the solenoid 421 is directed by the logic controller via the I/O interface 440 , high pressure gas is directed through a line 471 to actuate the chemical infusion valve 480 , which connects the fluid line 510 from the syringe pump 512 to the vaporization chamber 501 . When the solenoid 422 is directed by the logic controller via the I/O interface 441 , high pressure gas is directed through the line 470 to actuate the chemical infusion valve 481 , which connects the fluid line 511 from the syringe pump 513 to the vapor chamber 501 . [0047] When the solenoid 426 is directed by the logic controller via the I/O interface 444 , high pressure gas is directed through the line 467 to actuate valve 483 which allows for the introduction into the process chamber 500 of gas from the inlet 404 . When the solenoid 425 is directed by the logic controller via the I/O interface 443 , high pressure gas is directed through the line 465 to actuate the valve 485 , which allows for the introduction into the process chamber 500 of gas from the inlet 405 . [0048] When the solenoid 427 is directed by the logic controller via the I/O interface 445 , high pressure gas is directed through a line 468 to actuate the heated vapor valve 484 , which allows for the introduction into the process chamber 500 of vaporized chemical from the vapor chamber 501 via line 554 . Temperature indicating controller 524 and temperature alarm high switch are coupled to I/O interface 451 . [0049] Solenoid operated valves 428 , 429 allow the opening and closing of lines between the chemical reservoirs 502 , 503 and the syringe pumps 512 , 513 . I/O interfaces 458 , 459 control the operation of the solenoid operated valves 428 , 429 . [0050] The level of chemical left in the chemical reservoirs 502 , 503 is monitored with level sensors 514 , 515 and routed to the logic controller via the I/O interfaces 456 , 457 . Level sensors 514 , 515 are capacitance level switches P/N KN5105 by IFM Effector of Exton, Pa, in this embodiment. [0051] The vapor chamber pressure switch 464 is linked directly by a line 472 to a solenoid actuated valve 423 , which, when triggered, in turn triggers the gas actuated overpressurization limit relief valve 463 . The overpressurization limit relief valve 463 connects the vapor chamber 501 to the vacuum line inlet 406 . The vapor chamber pressure switch 464 triggers when the pressure in the vapor chamber 501 exceeds a preset pressure, which is 650 Torr in this embodiment. [0052] The process oven manometer 461 feeds its signal to the logic controller via an analog interface (not shown). Overtemperature alarm 551 feeds its signal to the logic controller via I/O interface 448 . An I/O interface 442 controls the solenoid actuated valve 424 , which in turn can trigger the gas actuated heated vacuum valve 482 via a line 466 , which links the process oven 500 to the vacuum inlet 406 . A temperature monitor 527 monitors the vacuum line temperature and is linked to the logic controller via an I/O interface 460 . Temperature alarm high switch 552 is linked to the logic controller via an I/O interface 460 . [0053] Temperature monitors 520 , 521 , 522 , 523 monitor the temperature in the process oven 500 . Temperature monitors 520 , 521 , 522 , 523 are linked to the logic controller by an RS-485 interface (not shown). Alarms are present in the temperature monitoring system and are linked to the logic controller by I/O interfaces 446 , 447 , 449 , 450 . [0054] Temperature monitors 524 , 525 connected to I/O interfaces 451 , 453 are also used to monitor the temperature of the heated vapor line 526 and the vapor chamber 501 . A pressure monitor 462 is linked to the logic controller by an analog interface and overtemperature alarm 553 is linked to the logic controller by an I/O interface 452 . [0055] A logic controller may be used to control this apparatus in some embodiments. An example of such a controller is Control Technology Corporation Model 2700 of Hopinkton, Mass. One of skill in the art will understand that the apparatus may be controlled using a variety of suitable methods. [0056] In one embodiment of the present invention, as seen in FIG. 4 , a chemical vapor deposition apparatus 101 has a vacuum subsystem 701 . Vacuum is applied to the vacuum subsystem 701 vacuum input supply line 735 . A heated vacuum valve 703 may be actuated to isolate the heated vacuum line 704 from the vacuum input supply line 735 . An example of the heated vacuum valve is P/N SS-8BK-VV-1C manufactured by Swagelok of Sunnyvale, Calif. The vacuum in the process chamber is measured using the chamber manometer 705 . An example of such a manometer is P/N 631A13TBFP manufacture by MKS of Andover, Md. Vacuum input supply line is fluidically coupled to the overpressurization limit relief valve 710 . An example of such a overpressurization limit relief valve is P/N SS-BNVS4-C manufactured by Swagelok of Sunnyvale, Calif. Overpressurization limit relief valve 710 couples vacuum input supply line 735 to line 709 . T-coupler 707 links line 708 , line 709 , and line 736 . Line 736 is fluidically coupled to vapor flask overpressurization limit switch 706 . The overpressurization limit switch 706 is electrically connected to a solenoid actuated valve which supplies high pressure gas that actuates the overpressurization limit relief valve 710 . An example of the vapor flask overpressurization limit switch is P/N 51A13TCA2AF650 by MKS of Andover, Md. Line 708 is fluidically coupled to vapor chamber 110 . [0057] A low pressure gas distribution manifold 733 distributes gas such as dry nitrogen for use in dehydration cycles. Inert gas such as dry nitrogen may be used in these lines. A purge manifold 732 allows for the purging of the fluid reservoirs and lines. The low pressure gas input line 522 is split at a T-coupler 723 into two serpentine lines 720 . Gas line heaters 721 allow for the pre-heating of the gas prior to delivery of the process chamber. T-couplers 724 , 729 further divide the delivery lines prior to input to the chamber at the gas inlets 725 , 726 , 727 , 728 . [0058] A high pressure gas distribution manifold 731 provides gas for purge manifold 732 which inserts low pressure nitrogen into the fluid reservoirs 106 , 107 . A line 730 routes gas to a fluidic coupler 211 in order to replace the volume voided by chemical withdrawal. Inert gas such as dry nitrogen may be used in these lines. The low pressure regulator 741 reduces the pressure from the high pressure gas distribution manifold 731 upstream from purge manifold 732 . The low pressure regulator 741 then provides gas to the purge manifold 732 . [0059] High pressure gas distribution manifold 731 provides high pressure gas that is routed to the gas actuated valves by the triggering of solenoid actuated valves in valve bank 740 . [0060] An alternative process gas distribution inlet 734 provides another inlet for process gas that may be used in some processes using this embodiment of the present invention. In this embodiment, the process gas lines are fluidically coupled to the low pressure gas lines upstream of the serpentine lines 720 . [0061] As seen in FIG. 5 , chemical vapor reaction apparatus 1001 has a touchpanel interface 1002 . The light tower 1003 signals status of the apparatus to persons in the vicinity. Door 1004 provides access to the process chamber. [0062] In some embodiments of the present invention, as seen in FIGS. 14 through 16 , the process oven 104 houses a plasma gas generation system. The plasma gas generation system resides predominantly within the process oven chamber walls 1401 . The gas plasma generation system is adapted to generate gas plasma within the process oven 104 . [0063] FIGS. 14 to 16 show several variations of capacitive plasma generation. Plasma may be generated with an appropriate gas in the presence of a strong electric field at an appropriate pressure. Capacitive plasma generation typically uses parallel plate electrodes to create the electric field. Electrodes may also be used to reduce the charging potential of a plasma and to concentrate the plasma in selected areas. [0064] Capacitive plasma electrodes are commonly referred to as being electrically active, electrically grounded, or electrically floating. An electrically active electrode has a high voltage, typically 400-600 volts, placed on it to create an electric field with respect to other electrodes. The voltage is typically alternating current at a high frequency. The industry standard frequency for plasma equipment is 13.56 MHz. There are advantages to using a lesser frequency in the 40 to 50 KHz range. An electrically grounded electrode is connected to ground with a appropriate conductor so that it remains at ground voltage potential. An electrically floating electrode is isolated from all other electrical potentials and will be at some voltage level that depends on the influence of the plasma upon it. [0065] FIG. 14 shows a horizontal electrode configuration that spans the process oven 104 . Plasma is generated primarily between active electrodes 1402 and grounded electrodes 1403 . Product material to be processed is typically place on the floating electrodes 1404 . To reach the product, plasma must pass through the perforated grounded electrode 1403 . Passing through the grounded electrode 1403 reduces the charging influence of the plasma and therefore reduces the charge that may be induced on the surface of product material by exposure to the plasma. [0066] FIG. 15 shows a vertical electrode configuration with grounded product trays 1411 . Plasma is primarily generated between active electrodes 1410 and grounded electrodes 1412 . Plasma passes through the perforated, grounded electrodes 1412 and reduces it charging influence. The region between the grounded electrodes 1412 has no electric field and therefore no plasma generation. However, plasma concentrates in regions with zero electric fields when plasma generation is at relatively low frequencies, 40-50 KHz. The configuration of FIG. 15 therefore concentrates plasma with low charging influence around grounded product trays 1411 . [0067] FIG. 16 shows a configuration similar to that of FIG. 15 with an additional plasma generation region in the center of the chamber 104 . Plasma is primarily generated between active electrodes 1420 and grounded electrodes 1422 , Once again, product trays 1421 are electrically grounded and in a region where plasma is concentrated but with low charging influence. [0068] In some embodiments, the product trays 1404 span the process oven 104 . Active electrodes 1402 and ground electrodes 1403 span the process oven 104 horizontally. The RF power supply, cabling, and RF power feed through are known in the art. [0069] In some embodiments, the plasma cleaning cycle may occur before the dehydration process. In an exemplary process, the chamber is evacuated. A gas is then introduced into the chamber and the pressure is stabilized at a low pressure, such as 150-200 milliTorr. In some embodiments, the introduced gas in oxygen. In some embodiments, the introduced gas is a combination of oxygen and argon. In some embodiments, other gasses are used. [0070] The plasma gas generation system allows for plasma gas cleaning of a work piece, such as a slide or substrate, in the same chamber as that in which subsequent process steps will take place. This gives many advantages, including reducing possible contamination that may occur if the work piece is exposed to the environment after plasma cleaning. Also, the plasma gas generation system can be used to clean the oven after the work pieces have been processed and removed. Many of the chemicals that may be used in processes that this chamber supports may leave residues that can interfere with subsequent runs. The plasma gas generation system may be utilized to clean the chamber after a process run and prior to loading the chamber with the work pieces for the next run. [0071] In some embodiments, as seen in FIG. 15 , the active electrodes 1410 and the ground electrodes 1412 may span the interior of the process oven 104 vertically. The product trays 1411 may span the process oven 104 horizontally between the ground electrodes 1412 . [0072] In some embodiments, as seen in FIG. 16 , there may be a plurality of vertical segments within the process oven 104 . The ground electrodes 1422 and the active electrodes 1420 reside vertically within the process oven 104 . The product trays 142 reside horizontally between ground electrodes 1422 . [0073] FIG. 6 shows a rear isometric view of apparatus 1001 . FIG. 7 is a partial cutaway side view of one embodiment of the present invention. FIG. 8 is a blown up section of the partial side view of FIG. 7 . FIG. 9 is a side view of one embodiment of the present invention. FIG. 10 is a rear view of one embodiment of the present invention. FIG. 11 is a top view of one embodiment of the present invention with the process door open. FIG. 12 is a rear view of one embodiment of the present invention. [0074] FIG. 13 is a cutaway view of the vacuum subsystem and the chemical reservoir purge subsystem. A manufacturer's chemical source bottle 1304 is the chemical reservoir in this embodiment. The purge regulator 1307 feeds the purge manifold 1306 with a gas such as nitrogen. A 5 psi relief valve 1308 is located downstream from the purge manifold in this embodiment. Gas is routed to the bottle 1304 via a line 1301 . Line 1301 connects to a fitting 1303 which routes the gas from line 1301 into the head portion of the source bottle 1304 . The withdrawal line 1302 couple to the fitting 1305 for withdrawal of the chemical from the source bottle 1304 . The tube supplying chemical to the withdrawal line 1302 terminates near the bottom of the inside of source bottle 1304 . Line 1301 is delivered gas from the purge manifold 1306 . [0075] A process for the coating of substrates in a process chamber, which may include dehydrating the substrate, gas plasma cleaning of the substrate, and vaporizing the chemical to be reacted prior to its entry into the process chamber. Subsequent to the processing of the substrate, the chamber may be cleaned using gas plasma. [0076] A substrate for the chemical deposition of different chemicals may be of any of a variety of materials. For biotech applications, a glass substrate, or slide, is often used. Glass substrates may be borosilicate glass, sodalime glass, pure silica, or other types. Substrate dehydration may be performed as part of some processes. The glass slide is inserted into the process chamber. The slide is then dehydrated. Residual moisture interferes with the adhesion of chemicals during the deposition process. Alternatively, dehydration of the slide allows for later rehydration in a controlled fashion. The dehydration process alternates exposing the glass slide to vacuum and then to heated nitrogen, either once or multiple times. For example, the glass slide would be exposed to a vacuum of 10 Ton for 2 minutes. At this pressure water boils at about 11 C. The vacuum chamber would then be flooded with preheated nitrogen at 150 C. This part of the process would heat the surface of the glass slide so that the high temperature of the slide would assist in the dehydration process as vacuum was once again applied. After 3 complete cycles, a vacuum of 1 Ton would be applied to complete the dehydration process. [0077] A gas plasma cleaning cycle may also be used in preparation of the substrate for coating. In a typical process, the substrate is cleaned using gas plasma after the dehydration process. In some embodiments, the plasma cleaning cycle may occur before the dehydration process. In an exemplary process, the chamber is evacuated. A gas is then introduced into the chamber and the pressure is stabilized at a low pressure, such as 150-200 milliTorr. In some embodiments, the introduced gas in oxygen. In some embodiments, the introduced gas is a combination of oxygen and argon. In some embodiments, other gasses are used. After the stabilization of the pressure in the process chamber, the electrodes are powered to generate the plasma. In an exemplary process, the electrodes are powered to 450 Volts cycled at 40 kiloHertz. The power cycle may last for 2 minutes in some embodiments. [0078] After the completion of the dehydration and plasma cleaning cycles, the slide or substrate is ready for chemical reaction. Chemical reservoirs, such as manufacturer's source bottles, provide the chemical for the deposition process. For many processes, silanes are used. Among the silanes used are amino silanes, epoxy silanes, and mercapto silanes. Chemical may be withdrawn directly from the reservoir. A metered amount of chemical is withdrawn from the chemical reservoir. This may be done by opening a valve between the chemical reservoir and a withdrawal mechanism. The withdrawal mechanism may be a syringe pump. Chemical is withdrawn from the reservoir, enters the syringe pump, and then the valve between the chemical reservoir and the syringe pump is closed. The chemical reservoirs may be purged with an inert gas such as nitrogen. This purging allows for the filling of the volume of fluid removed with an inert gas, minimizing contact between the chemical in the reservoir and any air or moisture. [0079] Next, a valve between the syringe pump and a vaporization chamber is opened. The vapor chamber may be pre-heated. The vapor chamber may be a reduced pressure. The syringe pump then pumps the previously withdrawn chemical from the syringe pump to the vaporization chamber. The vapor chamber may be at the same vacuum level as the process oven. In parallel to this delivery of chemical to the vaporization chamber, a second chemical may be undergoing the same delivery process. The two chemicals may vaporize at substantially the same time. Additionally, more chemicals may also be delivered to the vaporization chamber, or to another vaporization chamber. [0080] In some embodiments, the chemical or chemicals to be vaporized may be withdrawn from the reservoir or reservoirs in a specific metered amount. This specific amount of withdrawal and delivery to the vapor chamber may be repeated until the desired amount of chemical or chemicals has been delivered into the vapor chamber. For example, a metering pump may be used. The metering pump may deliver a pre-determined amount of chemical per stroke of the metering pump. The number of pump strokes may be selected, thus delivering a specified amount of chemical. [0081] The reduced pressure in the vapor chamber, and/or the elevated temperature in the vapor chamber may allow for the vaporization of chemicals at pre-determined pressure levels and temperatures. [0082] The vaporized chemical, or chemicals, are then delivered to the process chamber. This may be done by opening a valve between the vaporization chamber and the process oven after the chemical has vaporized in the vaporization chamber. Alternatively, the valve between the vaporization chamber and the process oven may already be open when the chemical, or chemicals, are delivered to the vaporization chamber. The chemical then proceeds into the process chamber and reacts with the substrate. [0083] In some embodiments, the chemical may be added into the vapor chamber with the valve between the vapor chamber and the process chamber open. The chemical may be continued to be added into the vapor chamber until the vapor pressure in the process chamber reaches a desired level. At that time, the valve between the vapor chamber and the process chamber may be closed. The chemical may then remain in the process chamber for the desired amount of time for reaction. [0084] In some embodiments, the chamber may be cleaned using gas plasma subsequent to the processing steps. The chamber may be emptied of all workpieces and then cleaned. The gas plasma cleaning step subsequent to the processing steps helps prepare the process chamber for subsequent processing. [0085] As evident from the above description, a wide variety of embodiments may be configured from the description given herein and additional advantages and modifications will readily occur to those skilled in the art. The invention in its broader aspects is, therefore, not limited to the specific details, representative apparatus and illustrative examples shown and described. Accordingly, departures from such details may be made without departing from the spirit or scope of the applicant's general invention.

A process for the coating of substrates comprising insertion of a substrate into a process oven, plasma cleaning of the substrate, dehydration of the substrate, withdrawal of a metered amount of one or more chemicals from one or more chemical reservoirs, vaporizing the withdrawn chemicals in one or more vapor chambers, and transfer of the vaporized chemicals into a process oven, thereby reacting with the substrate. An apparatus for the coating of substrates comprising a process oven, a gas plasma generator, a metered chemical withdrawal subsystem, and a vaporization subsystem.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a memory device that can be shared by a plurality of chips such as a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and more particularly to a memory device containing an arbiter performing arbitration for a bus access right. [0003] 2. Description of the Background Art [0004] Recently, systems equipped with CPU chips, memory chips and the like have attained high performance and multi-functions, and in addition to a CPU chip, a DSP, a chip having an operation function, such as a logic circuit (simply referred to as “logic” hereinafter) for performing a floating-point operation are often placed on-board. [0005] [0005]FIG. 1 is a block diagram showing an exemplary schematic configuration of a conventional system board having a CPU chip, a memory chip and the like thereon. The system board 101 includes memories 111 a - 111 c, a CPU 112 controlling the entire system, a DSP 113 processing data, and logic 114 performing processing including processing of an operation such as a floating-point operation. It is noted that system board 101 can externally input/output data through a system port. [0006] CPU 112 , logic 114 and DSP 113 are connected with memories 111 a , 111 b and 111 c through memory buses, respectively. CPU 112 , DSP 113 and logic 114 are connected through a system bus. [0007] CPU 112 mainly controls the entire system while accessing memory 111 . Logic 114 performs processing of an operation such as a floating-point operation while accessing memory 111 b . DSP 113 performs data processing while accessing memory 111 c . CPU 112 receives an operation result from logic 114 and a data processing result from DSP 113 through the system bus to control the system entirely. [0008] [0008]FIG. 2 is a block diagram showing an internal configuration of an asynchronous DRAM (Dynamic Random Access Memory) chip as exemplary memories 111 a - 111 c . This asynchronous DRAM chip includes a memory array 121 , an address input unit 122 externally inputting an address, an address decoder 123 decoding the address input from address input unit 122 , a command input unit 124 externally inputting a command, a control unit 125 interpreting the command input from command input unit 124 for control depending on the command, a data control unit 126 controlling writing data to memory array 121 and reading data from memory array 121 , and a data input/output unit 127 inputting/outputting data under the control of control unit 125 . [0009] Address decoder 123 selects a memory cell by decoding the address input from address input unit 122 and outputting the decoding result to memory array 121 . [0010] Control unit 125 interprets the command input from command input unit 124 to control a refresh operation, a precharge operation, a data reading operation, a data writing operation and the like. If the command is to read data, for example, data control unit 126 reads data from a memory cell selected by address decoder 123 and outputs data externally through data input/output unit 127 under the control of control unit 125 . [0011] [0011]FIG. 3 is a block diagram showing an internal configuration of a synchronous DRAM chip as another example of memories 111 a - 111 c . This synchronous DRAM chip includes a memory array 131 , an address input unit 132 externally inputting an address, an address decoder 133 decoding the address input from address input unit 132 , a command input unit 134 externally inputting a command, a control unit 135 interpreting the command input from command input unit 134 for control depending on the command, a clock input unit 136 externally inputting a clock signal, a control unit 137 performing a timing control in accordance with the clock signal input from clock input unit 136 , a data control unit 138 controlling writing data to memory array 131 and reading data from memory array 131 under the control of control unit 135 , and a data input/output unit 139 inputting/outputting data in synchronization with the clock signal output from control unit 137 . [0012] Address input unit 132 externally inputs an address in synchronization with the clock signal output from control unit 137 . Address decoder 133 selects a memory cell by decoding the address input by the address input unit 132 and outputting the decoding result to memory array 131 . [0013] Command input unit 134 externally inputs a command in synchronization with the clock signal output from control unit 137 . Control unit 135 interprets the command input by command input unit 134 to control a refresh operation, a precharge operation, a data reading operation, a data writing operation and the like. [0014] [0014]FIG. 4 is a block diagram showing another example of the schematic configuration of a conventional system board having a CPU chip, a memory chip and the like thereon. This system board 102 includes a memory 111 , a CPU 112 controlling the entire system, a DSP 113 processing data, logic 114 performing processing including processing of an operation such as a floating-point operation, and an arbiter 115 arbitrating for the right to access a memory bus. [0015] CPU 112 , DSP 113 and logic 114 are connected to memory 111 through the memory bus and share memory 111 . CPU mainly controls the entire system while accessing memory 111 . DSP 113 processes data while accessing memory 111 . Logic 114 performs processing of an operation such as a floating-point operation while accessing memory 111 . [0016] Arbiter 115 receives a request (Req) signal for acquiring the right to access memory 111 from CPU 112 , DSP 113 and logic 114 . The respective Req signals are provided with the priorities and arbiter 115 arbitrates for each request according to the respective priorities. Arbiter 115 then outputs an acknowledge (Ack) signal to that chip which acquires the right to access the memory bus. [0017] The chip that receives Ack signal outputs an address (Add) signal and the like and starts accessing memory 111 . Arbiter 115 controls memory 111 by outputting Add signal, a command and the like to memory 111 . [0018] [0018]FIG. 5 is a timing chart illustrating the operation of arbiter 115 mounted on system board 102 . In cycle 1, CPU 112 outputs Req signal for acquiring the right to access the memory bus to arbiter 115 . In cycle 2, arbiter 115 performs arbitration (Arb) for Req signal. At this point, there is no other chip that outputs Req signal, and therefore in cycle 3, arbiter 115 outputs Ack signal to CPU 112 . [0019] When CPU 112 receives Ack signal and recognizes that the right to access memory bus is acknowledged, in cycle 4, CPU 112 outputs Add signal and the like to arbiter 115 . At this point, arbiter 115 outputs Add signal, command (Act) and the like to activate memory 115 . In cycle 4, DSP 113 outputs Req signal to arbiter 115 . [0020] In cycle 5, arbiter 115 performs arbitration for Req signals for acquiring the right to access memory bus. Since CPU 112 is using the memory bus according to the priority, Ack signal is not output to DSP 113 . In cycles 6 to 9, arbiter 115 outputs a command to memory 111 in response to the request from CPU 112 and performs reading data (Read) or writing data (Write) from/to memory 111 . [0021] In cycle 9, logic 114 outputs Req signal to arbiter 115 . In this cycle, arbiter 115 completes reading data or writing data from/to memory 111 . [0022] In cycle 10, arbiter 115 performs arbitration for Req signals for acquiring the right to access memory bus. Since DSP 113 is using the memory bus according to the priority, Ack signal is not output to logic 114 . In this cycle, arbiter 115 outputs Ack signal to DSP 113 . [0023] In cycle 11, DSP 113 outputs Add signal and the like to arbiter 115 . At this point, arbiter 115 outputs Add signal, a command (Act) and the like to memory 111 to activate memory 111 . [0024] In cycles 13 to 16, arbiter 115 outputs a command to memory 111 in response to the request from DSP 113 and performs reading data (Read) or writing data (Write) from/to memory 111 . [0025] When arbiter 115 completes reading data or writing data from/to memory 111 , arbiter 115 outputs Ack signal to logic 114 in cycle 17. The similar processing is thereafter performed. [0026] In system board 101 shown in FIG. 1, no conflict over the memory access right occurs since the respective separate memories are connected to CPU 112 , DSP 113 and logic 114 . [0027] The number of memory chips mounted on system board 101 , however, is increased. As applications have increasingly attained high performance and multi-functions, the number of chips mounted on system board 101 has been increased accordingly, resulting in that the mounted area is inevitably increased. This contradicts the tendency for recent information terminal equipment to attain portability. [0028] In addition, since the capacity of a standard memory chip is defined beforehand, it is difficult to obtain a memory having a capacity required for CPU 112 , DSP 113 and logic 114 each. Therefore a memory having a capacity larger than the required capacity is often used. Unfortunately, this increases the cost for the entire system. [0029] On the other hand, in system board 102 shown in FIG. 4, the problem of system board 101 shown in FIG. 1 can be solved, since CPU 112 , DSP 113 and logic 114 share memory 111 . In the case where Req signals from CPU 112 and DSP 113 are in conflict as described above, however, Ack signal is not output to DSP 113 until the access to memory 111 by CPU 112 has been completed. Therefore the processing performance of the entire system is deteriorated. SUMMARY OF THE INVENTION [0030] An object of the present invention is to provide a memory device in which reduced processing performance of the entire system can be prevented. [0031] Another object of the present invention is to provide a memory device in which an increased area for mounting chips on a system board can be prevented. [0032] In accordance with an aspect of the present invention, a memory device includes a memory unit and an arbiter controlling the memory unit while arbitrating for bus access requests from a plurality of units. When a second bus access request takes place before an access to the memory unit that corresponds to a first bus access request has been completed, the arbiter performs activation of the memory unit that corresponds to the second bus access request in parallel with the access to the memory unit that corresponds to the first bus access request. [0033] Since the arbiter performs activation of the memory unit that corresponds to the second bus access request in parallel with the access to the memory unit that corresponds to the first bus access request, the access to the memory unit that corresponds to the second bus access request is allowed immediately after the access to the memory unit that corresponds to the first bus access request has been completed. As a result, processing performance can be improved. Furthermore, since a plurality of units can share the memory device, an increased area for mounting chips on the system board can be prevented. [0034] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0035] [0035]FIG. 1 is a block diagram showing an exemplary schematic configuration of a conventional system board having a CPU chip, a memory chip and the like thereon. [0036] [0036]FIG. 2 is a block diagram showing an internal configuration of an asynchronous DRAM chip as an exemplary memories 111 a - 111 c. [0037] [0037]FIG. 3 is a block diagram showing an internal configuration of a synchronous DRAM chip as another example of memories 111 a - 111 c. [0038] [0038]FIG. 4 is a block diagram showing another example of a schematic configuration of a conventional system board having a CPU chip, a memory chip and the like thereon. [0039] [0039]FIG. 5 is a timing chart illustrating an operation of arbiter 115 mounted on system board 102 . [0040] [0040]FIG. 6 is a block diagram showing a schematic configuration of a system board in an embodiment of the present invention. [0041] [0041]FIG. 7 is a timing chart illustrating an operation of an arbiter 15 contained in memory 11 in the embodiment of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT [0042] [0042]FIG. 6 is a block diagram showing a schematic configuration of a system board in an embodiment of the present invention. System board 1 includes a memory 11 , a CPU 12 controlling the entire system, a DSP 13 processing data, and logic 14 performing processing including processing of an operation such as a floating-point operation. Memory 11 includes an arbiter 15 arbitrating for the right to access a memory bus. Memory 11 has an internal configuration similar to that of the asynchronous DRAM chip shown in FIG. 2 or the synchronous DRAM chip shown in FIG. 3 except that it includes arbiter 15 , and therefore description thereof will not be repeated. [0043] Each unit such as CPU 12 , DSP 13 , or logic 14 is connected to memory 11 through the memory bus to share memory 11 . CPU 12 mainly controls the entire system while accessing memory 11 . Logic 14 performs processing of an operation such as a floating-point operation while accessing memory 11 . DSP 13 processes data while accessing memory 11 . [0044] CPU 12 , DSP 13 and logic 14 are connected to memory 11 through respective separate control buses 1 - 3 . Each of control buses 1 - 3 includes an address (Add) signal, a request (Req) signal for acquiring the right to access the memory data bus, and an acknowledge (Ack) signal for a request. [0045] Arbiter 15 receives Req signals for acquiring the right to access memory 11 from CPU 12 , DSP 13 and logic 14 . The respective Req signals are provided with priorities and arbiter 15 arbitrates for each request according to the priority. Arbiter 15 then outputs the acknowledge (Ack) signal to that chip which has acquired the right to access the memory bus. [0046] CPU 12 , DSP 13 and logic 14 start outputting Add signal before receiving Ack signal. When memory 11 is configured in DRAM with a bank configuration, a row address can be activated before the immediate preceding reading/writing cycle has been completed. Therefore in the present embodiment, memory 11 has arbiter 15 included therein and arbiter 15 has a plurality of address ports, so that arbiter 15 receives an address for the next reading/writing cycle to activate the row address in a different memory bank in advance before the immediate preceding reading/writing cycle has been completed. [0047] [0047]FIG. 7 is a timing chart illustrating the operation of arbiter 15 contained in memory 11 in the embodiment of the present invention. In cycle 1, CPU 12 outputs Req signal for acquiring the memory bus access right to arbiter 15 . In cycle 2, arbiter 15 performs arbitration (Arb) for Req signal. In cycle 3, since Add signal has already been output from CPU 12 , arbiter 15 outputs Add signal, a command (Act) and the like to memory 11 to activate a row address of a memory bank within memory 15 before outputting Ack signal. [0048] In cycle 4, arbiter 15 outputs Ack signal to CPU 12 since there is no other chip that outputs Req signal. In this cycle 4, DSP 13 outputs Req signal to arbiter 15 . [0049] In cycle 5, arbiter 15 performs arbitration for Req signal for acquiring the memory bus access right. Since CPU 12 is using the memory bus according to the priority, Ack signal is not output to DSP 13 . In cycles 5 to 8, arbiter 15 outputs a command to memory 11 in response to the request from CPU 12 and performs reading data (Read) or writing data (Write) from/to memory 11 . [0050] In cycle 6, since Add signal has already been output from DSP 13 , arbiter 15 outputs Add signal, a command (Act) and the like to memory 11 to activate a row address of a different memory bank within memory 11 . [0051] In cycle 8 in which arbiter 15 completes reading data or writing data from/to memory 11 , arbiter 15 outputs Ack signal to DSP 13 . In this cycle, logic 14 outputs Req signal to arbiter 15 . [0052] In cycles 9 to 12, arbiter 15 outputs a command to memory 11 in response to the request from DSP 13 and performs reading data (Read) or writing data (Write) from/to memory 11 . [0053] In cycle 9, arbiter 15 performs arbitration for Req signal for acquiring the memory bus access right. Since DSP 13 is using the memory bus according to the priority, Ack signal is not output to logic 14 . [0054] In cycle 10, since Add signal has already been output from logic 14 , arbiter 15 outputs Add signal, a command (Act) and the like to memory 11 to activate a row address of a different memory bank within memory 11 . [0055] In cycle 12 in which arbiter 15 completes reading data or writing data from/to memory 11 , arbiter 15 outputs Ack signal to logic 14 . The similar processing is thereafter performed. [0056] It is noted that although in the present embodiment it has been described that separate chips such as memory chip 11 , CPU 12 , DSP 13 , or logic 14 are mounted on system board 1 , these functions may be provided in the same chip as in a memory-embedded chip such as an SOC (System On a Chip) or an SIP (System In a Package). [0057] Inmost of the memory chips on system boards, a data bus width is at most ×32 bits (mainly ×16 bits). In the memory-embedded chip, however, the data bus width is sharply increased such as ×128 bits, ×256 bits, and the number of addresses is reduced with the increase in the number of bits. Therefore the configuration of the memory device in the present embodiment is more effective in the memory-embedded chip in which every unit is mounted on a single chip. [0058] It is noted that the configuration of the memory device in the present embodiment mounted on the memory-embedded chip differs from the configuration of system board 1 shown in FIG. 6 only in that the units including memory 11 , CPU 12 , DSP 13 , logic 14 and the like are mounted on a single chip. Therefore detailed description thereof will not be repeated. [0059] As described above, in accordance with the memory device in the present embodiment, memory 11 contains arbiter 15 , and arbiter 15 receives an address for the next reading/writing cycle to activate a row address in a different memory bank in advance before the immediate previous reading/writing cycle has been completed. As a result, the number of cycles required to access memory 11 can be reduced and the processing performance of the entire system can be improved. [0060] In addition, since CPU 12 , DSP 13 and logic 14 can share memory 14 , the increased area for mounting chips on system board 1 can be prevented. [0061] Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.

An arbiter performs activation of memory that corresponds to a bus access request from DSP in parallel with an access to memory that corresponds to a bus access request from CPU, when DSP requests to access the bus before the access to memory that corresponds to the bus access request from CPU has been completed. Therefore, immediately after the access to memory that corresponds to the bus access request from CPU has been completed, the access to memory that corresponds to the bus access request from DSP is allowed, thereby improving processing performance.

BACKGROUND OF THE INVENTION [0001] Production of proteins of interest is commonly achieved in transformed competent host cells. A problem that arises during purification of such proteins is that contaminant host proteins co-purify with the protein of interest. One approach to tackling this problem is to form a fusion protein between the protein of interest and a protein tag that has an affinity to a matrix. It is intended that the contaminant proteins are washed away and a pure protein is recovered. An example of a protein tag that is widely used is a histidine tag (His-tag). This binds to a metal containing column. The method is called immobilized metal ion affinity chromatography (see for example U.S. Pat. No. 5,310,663). [0002] Unfortunately, contaminating host cell proteins which do not carry any form of tag may contain non-consecutive histidine residues or other metal binding motifs exposed to the surface of their ternary structure. These contaminating proteins also bind to nickel and/or cobalt containing purification resins to which the His-tagged protein of interest binds (see Bolanos-Garcia and Davies, BBA 1760: 1304-1313(2006), and Edwards, et al., Nature Methods 5: 135-146(2008)), resulting in co-purification of these contaminants and failure to obtain a purified preparation of the protein of interest. SUMMARY OF THE INVENTION [0003] Embodiments of the invention provide a composition that includes a variant host cell derived from a parent host cell where the host cell may be a prokaryotic cell such as a bacterial cell such as E. coli or a eukaryotic cell. The parent host cell is characterized by a genome encoding a plurality of essential host proteins, wherein one or more essential proteins contain a plurality of histidines or basic amino acids residues such that when the cell is lysed, these essential proteins are capable of binding to a metal chelating matrix. Examples of such essential proteins include SlyD, carbonic anhydrase (can), ArnA, ArnD AceE, AceF and GlmS. [0004] In one embodiment, the variant viable host cell differs from the parent host cell in that in the variant, at least one of the plurality of essential proteins is additionally fused to an affinity binding tag encoded by the genome, the fusion proteins being capable of binding to a non-metal affinity matrix. Examples of affinity binding tags include: an immunoaffinity tag, a peptide tag selected from hemagglutinin, c-myc, T7, Glu-Glu, GST-tag, ZZ, GB1, MCP, and ACP, a streptavidin binding tag or a chitin binding domain tag. Alternatively, at least one of the plurality of essential proteins is mutated such that at least two of the plurality of histidines or basic amino acid residues is replaced with non-histidine residues such as alanine so that the mutated essential protein is no longer able to bind the metal chelating matrix. The variant host cell is capable of being transformed to express a recombinant target protein. [0005] The host cell variants may further include a non-host DNA encoding a protein of interest. [0006] In an embodiment of the invention, a method is provided of isolating a recombinant target protein from a cell lysate, that includes (a) lysing variant host cells of the type described above, wherein the variant host cells are transformed with DNA encoding a target protein fused to a histidine-tag, (b) subjecting the lysed host cells to a metal chelating matrix and a non-metal affinity binding matrix where the metal chelating matrix and the non-metal affinity binding matrix may be contained in the same or different reaction vessels; and (c) isolating the recombinant protein from the cell lysate. [0007] In another embodiment of the invention, a composition is provided which includes an affinity non-metal binding matrix and a metal chelating matrix proximately located in a reaction vessel suitable for receiving a mixture of components and suitable for separating a subset of the components from the mixture. [0008] In another embodiment of the invention, a method is provided of isolating a recombinant protein from a cell lysate. The method includes: lysing variant host cells that express a recombinant protein fused to a His-tag and purifying the recombinant protein away from essential protein contaminants that have histidine residues or basic amino acids and are capable of binding to a metal chelating matrix. This is achieved either by fusing the DNA encoding one or more essential proteins to DNA encoding an affinity binding tag and substituting the essential protein in the host cell chromosome using homologous recombination; or mutating at least two histidines or basic amino acids in the essential protein contaminant so that the one or more essential proteins no longer bind to a metal chelating matrix. The lysed host cells are then exposed to at least one of a metal chelating matrix and a non-metal binding matrix; and the purified recombinant protein is obtained from the cell lysate. BRIEF DESCRIPTION OF THE FIGURES [0009] The following description and the accompanying figures further describe and exemplify the features and advantages of the present invention, where: [0010] FIG. 1 shows pMAK-chitin binding domain (pMAKCBD) with a 3 prime polylinker sites and a 5 prime flank and target gene polylinker used for cloning of genomic DNA fragments for targeted allele exchange. [0011] FIG. 2 shows the nucleotide sequence of the pMAKCBD allele exchange vector (SEQ ID No: 49). [0012] FIG. 3A shows the results of gel electrophoresis of samples obtained by column fractionation of cell lysates of ER3135 over-expressing a target protein; His6-tagged alanine tRNA synthetase (AlaRS(6His)). The column used here is an Ni-NTA column (HisTrap™ column; GE Healthcare, Waukesha, Wis.). [0013] Lanes 1 and 10 contains a 10-250 kDa protein ladder (New England Biolabs, Inc., Ipswich, Mass.). [0014] Lane 11 is Ni-NTA column flow through. [0015] Lanes 2-9 and 12-22 are imidazole elution fractions containing eluted His-tag proteins and metal binding contaminating proteins. [0016] Arrows identify the target protein AlaRS(6His) (approx 90 kDa). The black box shows that native E. coli protein SlyD (approx. 26-28 kDa) is a metal binding contaminating protein and co-elutes with target AlaRS(6His) protein. [0017] FIG. 3B : shows the results of gel electrophoresis of samples obtained by column fractionation of cell lysates of ER3135(slyD-CBD derivative) over-expressing a target protein AlaRS(6His). The column used here is an Ni-NTA column. In the absence of a chitin purification step, it was shown here that the co-eluting SlyD-CBD migrated at a position that was consistent with the presence of the CBD-tag on the SlyD. [0018] Lanes 1 and 14 contains the 10-250 kDa protein ladder. [0019] Lane 15 is HisTrap™ flow through. [0020] Lanes 2-13 and 16-26 are imidazole elution fractions. [0021] The arrows identify AlaRS(6His). SlyD-CBD migrates at 35-40 kDa and is highlighted by a dotted black box. [0022] FIG. 3C shows results of a Western Blot in which anti-CBD antibody is applied to the gel in FIG. 3B confirming that the band on the gel at 35-40 kDa corresponds to SlyD-CBD contamination of the AlaRS(6His) in lanes 9-13 and 16-25 (see dotted black line box). [0023] FIG. 4 shows removal of the CBD-tagged contaminants from the AlaRS(6His) (protein of interest) using a chitin column following a Ni-NTA chromatography step (QIA express manual, (Qiagen, Germantown, Md.)). Ni-NTA and chitin column fractions were analyzed by Western blotting using an anti-CBD antibody (New England Biolabs, Ipswich, Mass.) which reacts with any CBD in the fraction. The positions of bands corresponding to AceE-CBD; ArnA-CBD; SlyD-CBD; and Can-CBD are marked. The host strain used in this experiment is ER3203. The Ni-NTA fractions correspond to lanes identified as Ly, S, ft, W1, W2 and P The fractions obtained after affinity binding to a chitin column overnight are shown in lanes F, W, B, F, W B. [0024] Lane L contains a biotinylated protein ladder (Cell Signaling Technology, Beverly, Mass.). [0025] Lane Ly is a sonication lysate. [0026] Lane S is a supernatant from the sonicated sample. [0027] Lane ft is a flow-through from the Ni-NTA column. [0028] Lane w1 contains the first wash of the Ni-NTA column. [0029] Lane w2 contains the second wash of the Ni-NTA column. [0030] Lane P contains the pooled fractions of Ni-NTA eluate which contain tagged protein without chitin column purification [0031] Lanes F contains a flow-through from chitin columns after 1 hr or 18 hrs of incubation. [0032] Lanes W contains a wash of chitin columns after 1 hr or 18 hrs of incubation. [0033] Lanes B contains the eluate obtained from boiling the chitin resin which had been incubated for 1 hr or 18 hrs. [0034] Lane WC contains whole cell lysate from E. coli ER3203 encoding AceE-CBD, ArnA-CBD, SlyD-CBD, Can-CBD and over-expressing AlaRS(6His). [0035] FIG. 5 shows positions of histidine (His) residues within the GlmS amino acid sequence which were mutated to alanine (Ala). Three mutants are shown: the GlmS(2Ala) mutant containing the mutations His62Ala and His65Ala, the GlmS(4Ala) mutant containing the mutations His432Ala, His436Ala, His466Ala and His467Ala, and the GlmS(6Ala) mutant containing all the mutations of the 2Ala and 4Ala mutants. [0036] FIG. 6 shows the results of SDS-PAGE of the Ni-NTA column elution of cell extract proteins of E. coli ER3135 expressing WT GlmS, Glms(2Ala) or GlmS(6Ala) from the pMAK705 vector. [0037] Lane (M) contains 7-175 kDa protein marker. [0038] Lane (K) shows Ni-NTA binding proteins from ER3135 expressing WT GlmS. [0039] Lane (2) shows Ni-NTA binding proteins from ER3135 expressing the GlmS(2Ala). [0040] Lane (6) shows Ni-NTA binding proteins from ER3135 expressing the GlmS(6Ala). An arrow indicates the expected position of GlmS (67 kDa) which is absent owing to the altered properties of GlmS(6Ala) that prevent it from binding. [0041] FIG. 7 shows SDS-PAGE results of over-expressing AlaRS(6His) in 3 strains—ER3135 which are wild type cells with no modification; Nico21(DE3) which contains three CBD-tagged non-target nickel binding proteins and GlmS(6Ala), and Nico22(DE3) which contains four CBD-tagged non-target nickel binding proteins and the GlmS(6Ala). [0042] M=marker [0043] P=pooled samples from Ni-NTA eluate enriched in AlaRS(6His) target protein [0044] FT=flow through after exposing Ni-NTA eluate to chitin resin [0045] B=eluate obtained from boiling the chitin resin to release bound CBD-tagged proteins [0046] Arrows identify AceE-CBD, AlaRS(6His), ArnA-CBD and SlyD-CBD. GlmS(6Ala) is not detected in Nico21(DE3) and Nico22(DE3) samples because the mutations eliminate binding to the Ni-NTA column. The position of WT GlmS is identified by a black triangle and WT SlyD is identified by black square in ER3135 pool (P) and flow through (FT). [0047] FIG. 8A-D are DNA sequences cloned into pMAKCBD in order to perform chromosomal allele exchange. [0048] FIG. 8A is a sequence of the aceE-CBD-aceF allele (SEQ ID NO: 50). [0049] FIG. 8B is a sequence of the arnA-CBD-arnD allele (SEQ ID NO: 51). [0050] FIG. 8C is a sequence of the can-CBD allele (SEQ ID NO: 52). [0051] FIG. 8D is a sequence of the slyD-CBD allele (SEQ ID NO: 53). [0052] FIG. 9 shows a schematic of the process of using a metal chelating matrix and an affinity binding matrix to purify a protein of interest expressed in Nico cells. [0053] 1. Cell lysate in solution is applied to the metal chelate chromatography column. [0054] 2. The lysate is allowed to flow through the column. The His-tagged protein of interest (*) and the affinity-tagged contaminating proteins (white squares and circles) remain bound to the column after rinsing. [0055] 3. The bound proteins are eluted with buffer which weakens the binding of the proteins to the metal ion. Fractions are collected from the column and tested for the presence of the protein of interest. Fractions containing the protein of interest are pooled. [0056] 4. The pooled fractions are applied to a second chromatography column containing a matrix which specifically binds the affinity-tagged contaminating proteins. The flow-through containing the isolated protein of interest is retained. [0057] 5. The affinity-tagged contaminating proteins bound to the matrix may be eluted with a buffer which weakens the binding of the affinity-tag to the matrix. A particular example is illustrated here, in which a column containing a chitin matrix is treated with boiling water to release bound CBD-tagged proteins. [0058] FIG. 10 shows a schematic of the process of using an affinity layer and a metal chelate layered column to purify a protein of interest expressed in Nico cells. [0059] 1. Cell lysate in solution is applied to a column containing distinct matrix layers, wherein the solution runs through a matrix layer which specifically binds affinity-tagged contaminating proteins (“affinity layer”) before the solution runs through a metal chelating matrix (“metal chelate layer”). [0060] Note: the position of the layers may be reversed so that the cell lysate is exposed to the metal chelate layer before the affinity layer. [0061] 2. The lysate is allowed to flow through the column and then the column is rinsed. The affinity-tagged contaminating proteins (white squares and circles) bind to the affinity layer while the His-tagged proteins of interest flow through the affinity layer and are bound by the metal chelate layer. [0062] 3. The bound proteins of interest are eluted with buffer which weakens the binding of the metal-binding peptide tag to the metal chelate layer but does affect the binding of the affinity-tagged proteins for the affinity layer. Fractions are collected from the column and tested for the presence of the protein of interest. Fractions containing the isolated protein of interest are retained. [0063] 4. The affinity-tagged contaminating proteins bound to the matrix may be eluted with a buffer which weakens the binding of the affinity-tag to the matrix. A particular example is illustrated here, in which a column containing a chitin matrix is treated with boiling water to release bound CBD-tagged proteins. DETAILED DESCRIPTION OF THE EMBODIMENTS [0064] Embodiments of the invention provide solutions to the problem of co-purification of contaminating essential host cell proteins containing histidines with His-tagged proteins of interest so that His tagged proteins of interest may be readily isolated from essential host cell proteins containing histidine residues. (“His-tag” as used here refers to more than 2 consecutive His residues in a protein fusion tag (EP0282042; U.S. Pat. No. 5,284,933, U.S. Pat. No. 5,310,663) and includes protein fusion tags capable of metal binding where histidine residues are non-consecutive (see US 2006/0030007 and U.S. Pat. No. 7,176,298)). The methods described herein can be readily applied to non-essential host proteins also although it is a relatively easy matter to delete or mutate the host genes encoding the non-essential proteins. [0065] In one embodiment, a desired expression strain was generated using an allele exchange vector containing a gene encoding a contaminating histidine-containing essential protein fused to an open reading frame (ORF) encoding a protein affinity binding tag. The term “affinity binding tag” refers to a peptide or protein that is not a metal binding protein or peptide. Once transformed with the plasmid, the host cell could express a fusion protein that included an affinity binding protein fused to the contaminating essential host protein wherein the essential protein was active and the host cell viable. The fusion gene was inserted into the host cell chromosome at the native gene locus to replace the native gene by homologous recombination (For example, see Hamilton, et al., Journal of Bacteriology: 4617-4622 (1989)). In this way viability of the host cell was preserved by expression of an active affinity-tagged protein from the native gene locus and subsequent expression of the His-tagged protein of interest was possible. [0066] The protein of interest could then be purified away from contaminating host metal binding proteins. In one embodiment, the crude cell lysate was first added to a metal chelating matrix which separates metal binding proteins from non-metal binding proteins resulting in a purified mixture of the protein of interest and contaminating histidine-containing fusion proteins. The fusion protein (affinity binding protein-contaminating essential host protein) was then removed by means of an affinity matrix from the target proteins. [0067] In other embodiments of the method, the metal binding chelating matrix could be used after binding of the cell lysate to an affinity matrix or both matrices could be used at the same time for purifying the protein of interest. The purification may be performed in separate or the same reaction vessels. [0068] Examples of E. coli host proteins that were reported to be co-eluted from IMAC resin in significant amounts were DnaK, GlmS, AceE, EF-Tu, ArnA, RNase E, AtpF, CRP, Can, the Rho transcription terminator and SlyD. The most consistent and significant contaminants are SlyD, GlmS, Can, ArnA and AceE. The examples show how genes expressing these proteins were targeted by modifying the host chromosome using homologous recombination. Using the same or similar approach, any desired protein additional to those in the examples can be similarly targeted and then removed from the preparation containing the protein of interest (target protein) by affinity-binding to a selected affinity matrix. [0069] There are a wide range of affinity binding proteins or peptide-tags known in the art that are characterized by being capable of binding to an affinity matrix. Any of these may be utilized in embodiments of the invention. These include: immuno-affinity tags such as FLAG tag (DYKDDDDK)(SEQ ID NO: 1) that binds to ANTI-FLAG® M2 Affinity Gel (Sigma, St. Louis, Mo.); hemagglutinin (HA); c-myc, T7; Glu-Glu (which mediates protein binding to the respective immobilized antibody or ligand (Table 9.9.1 in Current Protocols in Protein Science , authors Michelle E. Kimple and John Sondek (2004)); StrepII Tag (WSHPQFEK) (SEQ ID NO: 2) (that binds to streptavidin and StrepTactin™ resin (GE Healthcare, Waukesha, Wis.)); and Biotin Carboxyl Carrier Protein (BCCP) (a natural substrate for BirA biotin ligase (Cronan, J. E., J. Biol. Chem. 265:10327-10333 (1990)). BCCP-tagged proteins are biotinylated in vivo in birA+ expression hosts. The biotin group mediates protein binding to streptavidin and StrepTactin™ resin. AviTag™ (GeneCopoeia, Rockville, Md.) (GLNDIFEAQKIEWH) (SEQ ID NO: 3) may also be biotinylated by the BirA protein in vivo or in vitro (Beckett D., et al., Protein Science 8: 921-929 (1999)). This biotinylated peptide is capable of high affinity binding to streptavidin and StrepTactin™ resin. The S-Tag™ (EMD Biosciences, Darmstadt, Germany) binds to S-protein agarose. The GST-tag, ZZ-tag, GB1-tag are also suitable for contaminant protein tagging (F. Freuler, et al., Protein Expression and Purification 59: 232-241(2008)). YbbR-tags (J. Yin, et al., PNAS 102: 15815-15820 (2005)) may be specifically labeled with biotin by Sfp phosphopantetheinyl transferase for subsequent binding to streptavidin and StrepTactin™ resin. S6 and A1 peptides were identified from a phage-display library as efficient substrates for site-specific protein labeling catalyzed by Sfp and AcpS phosphopantetheinyl transferases (Zhou, Z., et al., ACS Chem. Biol. 2: 337-346 (2007)). Labeling with biotin-CoA allows for subsequent binding of the tagged protein to streptavidin and StrepTactin™ resin. The MCP-tag and ACP-tag (New England Biolabs, Inc., Ipswich, Mass.) may be labeled with derivatives of coenzyme A (e.g. biotin-CoA). In the labeling reaction, the substituted phosphopantetheine group of CoA is covalently attached to a conserved serine residue by SFP-Synthase or ACP-Synthase, respectively. CBD tag is small and binds chitin very tightly. In the examples described herein, the chitin binding domain from Bacillus circulans is used as the fusion affinity-tag for E. coli contaminant proteins. [0070] Where “matrix” is used, this is intended to refer to any of a porous or non-porous two dimensional surface coating of a surface such as a coating of surface of a reaction vessel or chip or three dimensional porous or non-porous structure such as a bead, column, or paper. [0071] The host cell can be any bacterial cell such as E. coli or a eukaryotic cell that is capable of being transformed or transfected with a vector suitable for making a protein of interest. [0072] Various vectors can be designed for use in homologous recombination such as for example, allele exchange vectors. A desirable feature of allele exchange vectors which recombine with the chromosome is the ability to select for those cells in which recombination has occurred. The examples of vectors provided here are not intended to be limiting and any person of ordinary skill in the art will appreciate that any selectable marker commonly in use will be effective. In the examples below, the pMAKCBD vector which contains a temperature-sensitive origin of replication, has a chloramphenicol selectable marker. These features allow for selection of cells where the vector is integrated in the chromosome when agar plates are incubated at the non-permissive temperature for plasmid replication. Alternatively, direct allele exchange may be performed by introduction of linear DNA into cells. Transformation of linear DNA is preferably linked to direct selection of cells with the desired phenotype. (Swingle B., et al., Mol. Microbiol. 75: 138-148 (2010)). [0073] The examples provided demonstrate the proof of principle described here using a CBD-tag fused to the essential contaminating proteins. Any of the other affinity-tags described may be utilized for this purpose. The contaminating proteins naturally contain a plurality of histidines or other basic amino acids that are capable of binding to a nickel column along with His-tagged proteins of interest. For essential contaminating proteins, the activity of the protein must be preserved to maintain viability of the host cell in order to express the protein of interest. [0074] Embodiments of the modified host cells described herein contain multiple contaminating essential proteins where some or all of the chromosomal genes encoding these proteins have been individually modified so as to be fused to a non-His-tag when expressed in the cell. In addition certain essential contaminating proteins may also be mutated such that the plurality of histidines (or basic amino acids) are replaced by a different amino acid such as alanine (GlmS)(see also Example 5). [0075] All references cited herein are incorporated by reference including Robichon et al. Applied and Environmental Microbiology, 77, p 4634-4646 (2011) and provisional application 61/381,736 which is the priority document for the present application. EXAMPLES [0076] To assist in understanding the present embodiments of the invention strain genotypes and descriptions are given below: [0000] Parent strain: ER3135=BL21(DE3) fhuA2 Thus ER3135=fhuA2 [Ion] ompT gal (α DE3) [dcm] ΔhsdS λ DE3 is defined as λ sBamHIo ΔEcoRI-B int::(lacI::PlacUV5::T7 gene1) i21 Δnin5 Derivative 1: ER3200=ER3135 carrying the slyD-CBD allele Derivative 2: ER3201=ER3135 carrying the slyD-CBD and can-CBD alleles Derivative 3: ER3202=ER3135 carrying the slyD-CBD, can-CBD, and arnA-CBD alleles Derivative 4: ER3203=ER3135 carrying the slyD-CBD, can-CBD, arnA-CBD and aceE-CBD alleles Derivative 5: ER3204=ER3135 carrying the slyD-CBD, can-CBD, arnA-CBD and glmS(6Ala) alleles aka (Nico21(DE3)) derivative 6: ER3205=ER3135 carrying the slyD-CBD, can-CBD, arnA-CBD, aceE-CBD and glmS(6Ala) aka (Nico22(DE3)) note: can is the carbonic anhydrase gene, also known as the yadF gene arnA is also known as yfbG. Example 1 Construction of the pMAKslyD-CBD and Allele Exchange to Replace the Chromosomal slyD Gene with slyD-CBD [0077] The pMAK705 vector (Hamilton, et al., Journal of Bacteriology: 4617-4622 (1989)) was modified to create a vector for introducing the CBD affinity tag open reading frame (ORF) at the 3′ end of chromosomal genes encoding contaminant proteins. CBD-ORF from vector pTYB1 (New England Biolabs, Inc., Ipswich, Mass.) was inserted into the polylinker region of pMAK705. A protein coding linker region was inserted upstream of the CBD-ORF. The linker region codes for the following nineteen amino acid sequence: LQASSS(N) 10 LQS (SEQ ID NO: 4), where the first LQ codons correspond to a PstI restriction site and the last LQS codons contain a SalI restriction site. (See FIG. 1 for a polylinker map of the C-terminal CBD-tagging vector named pMAKCBD). [0078] The allele exchange method described by Hamilton, et al. (1989) relies on homologous recombination. Efficient allele exchange occurs when the allele exchange vector contains at least 300 bp of homology to both the 5′ and 3′ regions flanking the target site on the bacterial host chromosome. These DNA segments of at least 300 bp are most easily isolated by PCR amplification from the target host chromosome and subsequently cloned into the allele exchange vector by restriction site ligation, ligase independent cloning (LIC), or uracil-specific excision reagent (USER) cloning (Sambrook, J., et al., Molecular Cloning: A Laboratory Manual, 2nd Ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. (1989); Aslanidis, C., et al., Nucleic Acids Research 18: 6069-6074 (1990); Haun, R. S., et al., Biotechniques 13: 515-518 (1992); and Bitinaite, J., et al., Nucleic Acids Research 35(6): 1992-2002 (207)). Alternatively, DNA fragments corresponding to target sites on the chromosome may be created by in vitro DNA synthesis techniques. We introduced useful restriction sites into the allele exchange vector to facilitate target gene cloning and 3′ flanking DNA cloning (see FIG. 1 ). Genes encoding E. coli essential proteins that contaminate samples on a nickel column may be cloned into the unique HindIII, SphI and/or PstI(SbfI) sites in the pMAKCBD allele exchange vector. DNA corresponding to 3′ gene flanking sequence may be cloned into the AsiSI, Acc65I and/or the EagI unique restriction sites to provide a 3′ region of homologous sequence. FIG. 2 shows the nucleotide sequence of the pMAKCBD allele exchange vector. [0079] pMAKslyD-CBD was constructed from pMAKCBD to replace the slyD allele in ER3135 with the slyD-CBD allele. The slyD gene of ER3135 was PCR-amplified with primers 4853 and 4854 and cloned into the HindIII and SbfI sites of pMAKCBD. In a second step, the 3′ flanking DNA downstream from the slyD gene was PCR-amplified from the ER3135 using primers 4855 and 4856 and cloned into the AsiSI and EagI sites to create clone pMAKslyD-CBD. [0000] TABLE 1 Primers and Primer Sequences for Construction of pMAKslyD-CBD Restriction Primer Sequence† Enzyme 4853For CCACCA AAGCTT GTTAAGTGCGGACATCAG HindIII (SEQ ID NO: 5) 4854Rev  GGTGGT CCTGCAGG TGGCAACCGCAACCGC SbfI CG (SEQ ID NO: 6) 4855For CCACCA GCGATCGC ATACCGAAAAAGTGAC AsiSI AAAAAAGCG (SEQ ID NO: 7) 4856Rev  GGTGGT CGGCCG GCAGCTTCAGCAGCAAAA EagI GTGA (SEQ ID NO: 8) †Underlined nucleotides indicate the recognition sequence of the restriction enzyme named in the rightmost column. [0080] SlyD was selected as the first contaminating essential protein to be tagged by the CBD-tag. pMAKslyD-CBD was transformed into ER3135 which is a T1-phage resistant version of BL21(DE3). We determined that selection of pMAK705-derived constructs in ER3135 was preferably undertaken using rich agar plates with chloramphenicol dosed at 4 ug/mL (“Rich-Cam4 plates”). The pMAKslyD-CBD construct was transformed into ER3135, and individual clones were grown in Rich-Cam4 liquid media until OD=0.5, and then approximately 2×10 6 colony forming units were plated on Rich-Cam4 agar. Plates were incubated at either 30° C. to allow plasmid replication or 42.5° C. to prevent plasmid replication. The ratio of colonies resulting from the two different plating temperatures was approximately 10,000/1. Thus, the chromosomal integration frequency was about 1 in 10 4 cells. PCR analysis was carried out on individual colonies to confirm slyD locus integration by the pMAKslyD-CBD construct. slyD locus integration was confirmed by positive PCR amplification using a forward primer specific for the plasmid (s1233) and reverse primer 4060, annealing to the chromosomal DNA downstream of the slyD locus (and outside of the sequence cloned into pMAK-slyD-CBD). Positive integrants were inoculated into rich media with Cam concentration dosed at 10 ug/mL (“Rich-Cam10 media”) and grown at 30° C. to enable re-activation of the plasmid origin of replication. The higher level of Cam (10 ug/mL) encourages growth of the strains where the pMAK construct becomes episomal. Thus, after three continuous outgrowths to saturation, the respective culture was populated with cells containing replicating plasmid. The plasmid allele was analyzed by PCR amplification using primers s1233 and s1224. Strains where allele exchange occurred were identified by the size of the PCR amplicon and additionally by resistance to MfeI digestion. The CBD-ORF contains a unique MfeI site that is useful for allele exchange analysis. The strains positive for allele exchange were cured of the pMAK vector carrying the WT slyD allele derived from the chromosome. pMAK vector curing was accomplished by coumermycin treatment (Chen, et al., J. Biol. Chem. 278: 23295-23300(2003)). The cured strain (ER3200) was genetically characterized by sequencing the slyD-CBD allele amplified by primers 4059 and 4060. PCR amplification with these two primers confirmed that the slyD-CBD allele was present at the correct position within the chromosome. The amplified ER3200 genomic DNA was sequenced to confirm the presence of an in-frame genetic fusion between the slyD gene and the CBD-ORF. Strain ER3200 exhibited the same growth rate in rich media when compared to parent strain ER3135. [0000] TABLE 2 Primers and Primer Sequences  for Allele Exchange to Create the  slyD-CBD Derivative of ER3135 Primer Sequence S1233For AGCGGATAACAATTTCACACAGGA (SEQ ID NO: 9) 4060Rev GCACCCAGTGCATAAGCTGATTTCT (SEQ ID NO: 10) S1224 CGCCAGGGCCCAGTCACGAC (SEQ ID NO: 11) 4059Forv GCCTGTCAGGCGCAGGATTCA (SEQ ID NO: 12) [0081] FIG. 3A demonstrates the problem of wild type SlyD co-eluting from Ni-NTA resin with the his-tagged protein of interest (also referred to as a target protein) over-expressed in parent strain ER3135. FIG. 3B shows co-elution of SlyD-CBD from Ni-NTA resin with the target protein after overexpression in the slyD-CBD derivative strain ER3200. Note that SlyD-CBD protein exhibits a much slower migration rate in SDS-PAGE when tagged with the 7 kDa CBD-tag. FIG. 3C confirms that the most of the Ni-NTA elution fractions shown in FIG. 3B are contaminated with the SlyD-CBD fusion protein (prior to chitin affinity chromatography). Example 2 Construction of pMAKcan-CBD and Allele Exchange to Tag the Chromosomal can Carbonic Anhydrase Gene [0082] A second contaminating essential protein chosen for tagging was the can gene product carbonic anhydrase. The 3′ flanking DNA downstream of the can gene (formerly yadF) was PCR-amplified from ER3135 genomic DNA using primers 4839 and 4840 and cloned into the AsiSI and EagI sites of pMAKCBD. The can gene was PCR-amplified from ER3135 genomic DNA using primers 4841 and 4842 and cloned into the HindIII and SacI sites. The resulting construct pMAKcan-CBD was confirmed by DNA sequencing and then transformed into ER3135. The allele exchange procedure was carried out in the same manner described in Example 1, except that chromosomal integration analysis and can locus amplification were accomplished using primers 4841 and 2187. [0083] The can-CBD derivative of ER3135 exhibited the same growth rate in rich media as the parent strain. Thus, we proceeded to add the can-CBD allele to strain ER3200 (slyD-CBD strain) by allele exchange to create the double CBD-tagged derivative ER3201, which also exhibited the same growth rate in rich media when compared to parent strain ER3135. [0000] TABLE 3 Primers and Primer Sequences for  Construction of pMAKcan-CBD  and Allele Exchange Restriction Primer Sequence Enzyme 4839For ACCACC GCGATCGC AAATGCCATGCCGGAT AsiSI GCAACACATCC (SEQ ID NO: 13) 4840Rev ACCACC CGGCCG CATATGGTTAGAGATATG EagI AAACATAC (SEQ ID NO: 14) 4841For ACCACC AAGCTT CGAGATCGTAACCAAATA HindIII CGCTG (SEQ ID NO: 15) 4842Rev ACCACC GAGCTC GATTTGTGGTTGGCGTGT SacI TTCAGCTTGAG (SEQ ID NO: 16) 2187Rev CGAGTAATCGTCGCGAGCCTGTATTG  (SEQ ID NO: 17) †Underlined nucleotides indicate the recognition sequence of the restriction enzyme named in the rightmost column. Example 3 Construction of pMAKarnA-CBD-arnD and Allele Exchange to Tag the Chromosomal arnA Gene at the 3′End [0084] The ArnA protein was selected as the third contaminating essential protein for CBD-tagging. The arnA gene resides within an operon where the arnA stop codon overlaps the downstream arnD gene start codon (ATGA). To maintain this native genetic context at the arnA/arnD junction, we designed the arnA-CBD-arnD allele to encode the last 4 codons of arnA after the CBD-ORF so that the native arnA/arnD junction would be maintained. This engineered allele expresses an ArnA-CBD fusion protein with the DKPS amino acid sequence repeated before and after the C-terminal CBD-tag. The pMAKarnA-CBD-arnD construct was created as follows. First, the arnD gene was PCR-amplified from ER3135 genomic DNA using primers 9990 and 0001 (see Table 4). Next, the pMAKCBD vector was PCR-amplified using primers 0003 and 9991 to create a blunt ended DNA that ends with the last codon of the CBD-ORF. Ligation of these two fragments creates a genetic fusion coding for CBD-DKPSArnD. Finally, the arnA gene was PCR-amplified from ER3135 genomic DNA using primers 0000 and 0002 and cloned into the HindIII and PstI sites to create the final allele exchange construct pMAKarnA-CBD-arnD. [0085] The arnA-CBD-arnD allele was inserted at the arnA-arnD locus of ER3135 using the allele exchange method as described in Examples 1 and 2. Chromosomal integration analysis and arnA-arnD locus amplification was accomplished using primers 5032 and 5031. The arnA-CBD-arnD derivative of ER3135 exhibited the same growth rate in rich media when compared to parent strain ER3135. Thus, the arnA-CBD-arnD allele was also added to strain ER3201 to create the triple CBD-tagged strain ER3202. [0000] TABLE 4 Primers and Primer Sequences for  Construction of pMAKarnA-CBD-arnD  and Allele Exchange Restriction Primer Sequence†‡ Enzyme 9990For P-GATAAACCATCATGACCAAAGTAGG  (SEQ ID NO: 18) 0001Rev CAGGTG GGTACC GTCACCGGAATTTGC Acc65I G (SEQ ID NO: 19) 0003 GATATTGCTG GGTACC GAGCTCGAA  Acc65I (SEQ ID NO: 20) 9991 P-TTGAAGCTGCCACAAGGCAGGAACG  (SEQ ID NO: 21) 0000For CGGCAT AAGCTT ACTCGGTGAATATAT  HindIll CGG (SEQ ID NO: 22) 0002Rev P-AGCCTGCAGGGAAGGTTTATCCGTA AGATCAACGGTGCG  (SEQ ID NO: 23) 5032For GATGTACGACCTGGTGACCTGC  (SEQ ID NO: 24) 5031Rev GGATGCGGTTGAGTAACCAACC (SEQ ID NO: 25) †Underlined nucleotides indicate the recognition sequence of the restriction enzyme named in the rightmost column. ‡“P” indicates the position of phosphorylation. Example 4 Construction of pMAKaceE-CBD and Allele Exchange to Tag the Chromosomal aceE Gene at the 3′End [0086] The AceE protein was selected as the fourth contaminating essential protein for CBD-tagging. The aceE gene codes for the E1 subunit of the pyruvate dehydrogenase mufti-subunit complex. The downstream chromosomal gene is aceF, which codes for the E2 subunit of the pyruvate dehydrogenase complex. Together with the dihydrolipoyl dehydrogenase subunit (E3), this key metabolic enzyme is composed of E1:E2:E3 at a ratio of 24:24:12 subunits per complex in E. coli (Lehninger et al. “ Principles of Biochemistry” 2 nd edition, 1993 by Worth Publishers). Thus, the expression level of each subunit is important to the viability of the cell. [0087] The pMAKaceE′-CBD-aceF allele exchange clone maintained the native 14 nucleotide spacing between the aceE and aceF genes: TAA GAGGTAAAAGAATA ATG (SEQ ID NO: 26). The aceE′ designation indicates that the aceE gene is truncated at the 5′ end. Thus, integrants were not isolated in the first step of the allele exchange method if the aceE-CBD allele was not tolerated. pMAKaceE′-CBD-aceF was constructed as follows: First, the full-length aceE gene was cloned using primers 4845 and 4846 (see Table 5). Then, the 5′ end of aceE was deleted by SphI-BsiWI digestion, followed by a blunting reaction with Klenow fragment and ligation to reclose the plasmid. Next, the full-length aceF gene was PCR-amplified from ER3135 using primers 0077 and 0076 and cloned into the deltaSphI-BsiWI clone. The vector fragment was prepared by PCR-amplification using 0079 and 0078 and subsequent digestion with EagI. [0088] pMAKaceE′-CBD-aceF allele exchange construct was transformed into the triple CBD-tagged strain ER3202 to create the quadruple CBD-tagged strain ER3203. Primers 4845 (upstream forward) and 0078 (CBD-tag reverse) were used to confirm proper integration at the aceE locus. Primers 4845 and 0076 were used to PCR-amplify the aceE locus for sequence characterization. The amplicon was digested with MfeI to rapidly identify the strains encoding aceE-CBD at the aceE locus as the WT aceE gene lacks this site and the CBD-ORF contains a single MfeI site. [0089] Strain ER3203 exhibited a reduced growth rate in rich media when compared to parent strain ER3135. However, the same cell density was obtained after overnight shaking (225 rpm at 37° C. in 2 L flasks). Under high-density cultivation conditions, ER3203 achieved a saturation density of OD600=31.6, whereas ER3135 achieved a saturation density of OD600=91.3 when both strains were induced with 1 mM IPTG to over-express Alanyl tRNA-synthetase(6His) from a plasmid. In the same experiment, the triple CBD-tagged strain ER3202 achieved a saturation density of OD=100.1 and the 6His expression level was comparable to the expression level observed in ER3135. [0000] TABLE 5 Primers and Primer Sequences for  Tagging the 3′ End of the aceE  Gene with the CBD-ORF Restriction Primer Sequence†‡ Enzyme 4845For ACCACC GCATGC GAATTGCTCTAT SphI TCGCGTCGCGAGATG (SEQ ID NO: 27) 4846Rev ACCACC GAGCTC GACGCCAGACGC SacI GGGTTAACTTTATCTGC (SEQ ID NO: 28) 0077For P-GAGGTAAAAGAATAATGGCTAT CG (SEQ ID NO: 29) 0076Rev CAAACG GCGGCCGC TTTGTCTATT NotI CGCTA (SEQ ID NO: 30) 0079For CAGCTC CGGCCG ACGCGCTGGGCT  EagI (SEQ ID NO: 31) 0078Rev P-TTATTGAAGCTGCCACAAGGCA GG (SEQ ID NO: 32) †Underlined nucleotides indicate the recognition sequence of the restriction enzyme named in the rightmost column. ‡“P” indicates the position of phosphorylation. Example 5 Construction and Evaluation of GlmS Mutants with Either Two or Six Surface Histidines Replaced by Alanines [0090] The chromosomal glmS gene was mutated to replace histidine codons with alanine codons so that the respective strain would express a GlmS protein with reduced affinity for IMAC resins. FIG. 5 shows positions of histidine codons within the glmS gene, which were mutated to alanine in the mutants described below. [0091] The pMAK-glmS clone was generated by PCR amplification of the glmS gene from ER3135 genomic DNA with the primers HindIII-glmS For and glmS-SacI Rev (see Table 6). This PCR product corresponding to the glmS gene with 200 bp 5′ flanking sequence and no 3′ flanking sequence was cloned into the HindIII and SacI sites of pMAK705. [0092] pMAK-glmS(2Ala) was generated by PCR amplification of the plasmid pMAK-g/mS with the reverse primer 3 (His62Ala) and forward primer 4 (His65Ala) and followed by ligation to circularize the linear PCR product (Phusion® Site-Directed Mutagenesis Kit, New England Biolabs, Inc., Ipswich, Mass.). The glmS(2Ala) gene has the sequence GC TCCTCTG GC T (SEQ ID NO: 33) modified from the WT sequence (CATCCTCTGCAT) (SEQ ID NO: 34) so that the four mutated nucleic acids resulted in alanine codons at positions 62 and 65 of the glmS ORF. [0093] pMAK-glmS(4Ala) was generated by PCR amplification of the plasmid pMAK-glmS(2Ala) with the reverse primer 5 (His432Ala) and forward primer 6 (His436Ala) followed by the ligation to circularize the linear PCR product. The glmS(4Ala) has the sequence GC TGACATTGTG GC (SEQ ID NO: 35) modified from the glmS(2Ala) sequence (CATGACATTGTGCAT) (SEQ ID NO: 36) so that the four mutated nucleic acids resulted in additional alanine codons at positions 432 and 436 of the glmS ORF. [0094] pMAK-glmS(6Ala) was generated by 2 PCR amplifications. First, the pMAK-glmS(4Ala) template was amplified with the reverse primer 7 containing two mutated bases resulting in a DNA encoding (His466Ala) in the GlmS and the forward primer 8 (His467Ala) and followed by the ligation of the linear PCR product to generate the plasmid pMAK-glmS(5Ala) (His62Ala, His65Ala, His432Ala, His436Ala, His466Ala). Second, the pMAK-glmS(5Ala) template was amplified with the reverse primer 9 (His466Ala) and the forward primer 10 (His467Ala) followed by ligation of the linear PCR product to generate the plasmid pMAK-glmS(6Ala). The glmS(6Ala) has the sequence AAA GC T GC CGCG (SEQ ID NO: 37) modified from the glmS(4Ala) sequence (AAACATCACGCG) (SEQ ID NO: 38) so that the four mutated nucleic acids resulted in additional alanine codons at positions 466 and 467 of the glmS ORF. [0095] FIG. 6 shows results from over-expressing the WT GlmS protein, the GlmS(2Ala) protein and the GlmS(6Ala) protein from the pMAK vector (lac promoter) in ER3135. In each case, cell lysates were prepared and subjected to ÄKTA™ HisTrap™ chromatography (GE Healthcare, Waukesha, Wis.). The results show that the GlmS(6Ala) does not bind to the HisTrap™ resin whereas the GlmS wild type protein and the GlmS(2Ala) do bind to the resin in the presence of 20 mM imidazole. [0000] TABLE 6 Primers and Primer Sequences for Construction and Evaluation of GlmS Mutants Primer Sequence* HindIII- GGAGGA AAGCTT GACTCAGAA glmS For AGAAGGCTGG (SEQ ID NO: 39) glmS- CCACCA GAGCTCTTATTA CTC SacI Rev AACCGTAACCGATTTTGCC  (SEQ ID NO: 40) His62- GGA GC TTCTTCCGCTGCCTGA Ala Rev GCC (SEQ ID NO: 41) His65Ala  TCTG GC TGGCGGCACCGGTAT For TGCTCAT (SEQ ID NO: 42) His432Ala ATGTCA GC TTCAATGGAGGCA Rev TCCAGACCTT (SEQ ID NO: 43) His436Ala  TGTG GC TGGTCTGCAGGCGTT For GCCGAGCCGTAT (SEQ ID NO: 44) His466Ala A GC TTTGTCAGAGAAATCTTC  Rev (SEQ ID NO: 45) glmS467  C ACGCGCTGTTCCTGGGCCGT  For (SEQ ID NO: 46) glmS466  A TGTTTGTCAGAGAAATCTTC  REV (SEQ ID NO: 47) His467Ala  GC CGCGCTGTTCCTGGGCCGT For GGCGATCAG (SEQ ID NO: 48) *Bold and underlined nucleotides indicate mutations relative to WT glmS sequence. Example 6 Allele Exchange to Introduce the glmS(6Ala) Mutant Gene [0096] pMAK-glmS(6Ala) construct was transformed into strains ER3202 and ER3203 and the allele exchange method was used to replace the chromosomal WT glmS gene with the glmS(6Ala) gene. The protein expression host derived from ER3202 was named NiCo21(DE3) and the host derived from ER3203 was named NiCo22(DE3). Example 7 Mass Spectrometry Analysis of E. coli Ni-NTA Binding Proteins from: ER3135, Nico21(DE3) and Nico22(DE3) [0097] Mass spectrometry analysis of E. coli proteins which bound to a Ni-NTA column (Qiagen, Germantown, Md.) from: ER3135, Nico21(DE3) and Nico22(DE3). Each strain was grown to saturation at 37° C. in luria broth (LB) plus 0.1% glucose. Cell pellets were resuspended in buffer A [20 mM sodium phosphate (pH 7.4), 0.5M NaCl, 20 mM imidazole] and sonicated to prepare a cell lysate. The clarified lysate was loaded onto a 1 mL HisTrap™ column. The column was washed with 90 column volumes of buffer A (20 mM imidazole). Then the high affinity Ni-NTA binding proteins were eluted with buffer A containing 400 mM imidazole. The eluted proteins were analyzed by mass spectrometry. Zero GlmS peptides were detected in the samples originating from Nico21(DE3) and Nico22(DE3) in contrast to the parent strain where GlmS was the primary Ni-NTA binding protein. Example 8 Overexpression of Target Protein Alanyl tRNA-Synthetase in ER3135, Nico21(DE3) and Nico22(DE3) [0098] The E. coli protein contaminant profile was evaluated when His-tagged Alanyl tRNA synthetase was over-expressed from pQE30 (Qiagen, Germantown, Md.) in three strains of interest: ER3135=BL21(DE3) fhuA versus Nico21(DE3) versus Nico22(DE3). Note that each strain also carried the miniF-lacIq plasmid isolated from T7 Express I q (New England Biolabs, Inc., Ipswich, Mass.). Cell lysates resulting from 500 mL of IPTG-induced cells were loaded, washed and eluted from a 5 mL HisTrap™ column according to manufacturer's recommendations. The imidazole elution fractions enriched in 6His were pooled (see lanes P in FIG. 7 ). The Ni-NTA pools (P) were passed through a chitin column. The proteins flowing through the chitin column are shown in lanes FT in FIG. 7 . Finally, lanes labeled B were the result of boiling the chitin resin in the presence of SDS to strip the resin of CBD-tagged proteins. As expected, very little protein is present in FIG. 7 lane B of ER3135 since this is the parent strain lacking CBD-tagged proteins. In contrast, lanes B corresponding to Nico21(DE3) and Nico22(DE3) are enriched with CBD-tagged proteins that have been removed from the target protein (as indicated in FIG. 7 ). A black triangle indicates the 67 kDa GlmS protein in lanes P and FT of ER3135, whereas the GlmS protein is absent in all lanes corresponding to Nico21(DE3) and Nico22(DE3).

Compositions relating to a combination of two types of separation matrix; and to variant host cells which contain at least one essential host protein that is fused to an affinity binding tag or has been mutated to replace at least two of a plurality of histidines or basic amino acids are provided. Methods are also provided that relate to isolating a recombinant protein from a lysate.

RELATED APPLICATIONS This application is a continuation application of U.S. application Ser. No. 12/462,312, filed Aug. 3, 2009, which is related to, and claims priority of, U.S. provisional application No. 61/086,678 filed on Aug. 6, 2008, by Donald Burn and Jack J. Stiffler. FIELD OF THE INVENTION This invention relates to software techniques and procedures for achieving fault tolerance in computer systems and, more particularly, to techniques and procedures for establishing and recording a consistent system state from which all running operating systems and applications can be safely resumed following a fault. BACKGROUND OF THE INVENTION “Checkpointing” has long been used as a method for achieving fault tolerance in computer systems. It is a procedure for establishing and recording a consistent system state from which all running applications can be safely resumed following a fault. In particular, in order to checkpoint a system, the complete state of the system, that is, the contents of all processor and input/output (I/O) registers, cache memories, and main memory at a specific instance in time, is periodically recorded to form a series of checkpointed states. When a fault is detected, the system, possibly after first diagnosing the cause of the fault and circumventing any malfunctioning component, is returned to the last checkpointed state by restoring the contents of all registers, caches and main memory from the values stored during the last checkpoint. The system then resumes normal operation. If inputs and outputs (I/Os) to and from the computer are correctly handled, and if, in particular, the communication protocols being supported provide appropriate protection against momentary interruptions, this resumption from the last checkpointed state can be effected with no loss of data or program continuity. In most cases, the resumption is completely transparently to users of the computer. Checkpointing has been accomplished in commercial computers at two different levels. Early checkpoint-based fault-tolerant computers relied on application-directed checkpointing. In this technique, one or more backup computers were designated for each running application. The application was then designed, or modified, to send periodically to its backup computer, all state information that would be needed to resume the application should the computer on which it was currently running fail in some way before the application was able to establish the next checkpoint. This type of checkpointing could be accomplished without any specialized hardware, but required that all recoverable applications be specially designed to support this feature, since most applications would normally not write the appropriate information to a backup computer. This special design placed a severe burden on the application programmer not only to ensure that checkpoints were regularly established, but also to recognize what information had to be sent to the backup computer. Therefore, in general, application-directed checkpointing has been used only for those programs that have been deemed especially critical and therefore worth the significantly greater effort required to program them to support checkpointing. System-directed checkpointing has also been implemented in commercial computer systems. The term “system-directed” refers to the fact that checkpointing is accomplished entirely at the system software level and applications do not have to be modified in any way to take advantage of the fault-recovery capability offered through checkpointing. System-directed checkpointing has the distinct advantage of alleviating the application programmer from all responsibility for establishing checkpoints. System-directed checkpointing involves periodically establishing checkpoints in which the system state at that instant is recorded in such a way that, should a fault occur before reaching the next checkpoint, the system can be rolled back and the state that prevailed at the last checkpoint can be restored. Either of two basic methods is used to accomplish this. The first, called pre-image checkpointing, requires the contents of any page in memory to be copied to a checkpoint buffer before that page is allowed to be modified. The second, called post-image checkpointing, depends on the existence of a shadow memory with a shadow page for each page in main memory. On this case, when an attempt is made to write to a page in main memory, its address is captured and placed on an address queue. Following each checkpoint, all modified pages are copied into a shadow buffer and from there into the shadow memory. While system-directed checkpointing has obvious advantages over application-directed checkpointing, its implementation has traditionally been accomplished through the use customized hardware and software, making it virtually impossible for such systems to remain competitive in an era of rapidly advancing state-of-the-art commodity computers and operating systems. More recently, techniques have been disclosed for achieving system-directed checkpointing on standard computer platforms. These techniques, however, all require either modified hardware or else modifications to the operating system kennel. The first of these techniques involves modifying the hardware to capture the information needed to establish a checkpoint. This procedure is best implemented in the memory controller hardware, but unfortunately, standard memory controllers do not support the required functionality. The second technique entails modifying the operating system kernel to enable certain memory writes to be interrupted momentarily so that either the pre-image of the addressed section of memory, or the address itself, can be captured and recorded elsewhere in memory. The problem with this approach is that it can be implemented only on systems having operating systems that have been so modified. SUMMARY OF THE INVENTION A procedure is described for endowing otherwise standard computers with a high level of fault tolerance at a very modest incremental cost, without requiring either the hardware or the operating system kernel to be modified in any way. This procedure is implemented through the addition of a virtual operating system layer, called the “virtual layer”, the “virtual machine monitor” or the “hypervisor”, that sits between any standard operating system, called the “guest operating system”, and the computer hardware. Hypervisor layers have become increasingly prevalent in data centers and even in desktop computers because of the advantages they afford in system management, operating environment versatility and computer resource allocation. Conceptually, the hypervisor is a specialized operating system, but instead of hosting user applications, it serves as the host to other operating systems, which, in turn, host user applications. State-of-the-art processors provide support for hypervisor systems by, in effect, implementing three levels of operation, an application level, an operating system level and a hypervisor level. Each guest operating system controls a virtual computer and allocates that computer's resources in the normal way. But any attempt to allocate the computer's physical, as opposed to virtual, resources, results in a trap to the hypervisor. The hypervisor, in response to such a trap performs the operation on behalf of the host operating system, but, depending on the specific operation and on the circumstances under which it is attempted, it may, in accordance within the present invention, extend the operation so as to support checkpointing and other fault tolerant features. When the hypervisor is implemented as detailed herein and used in conjunction with the checkpointing and rollback procedures described in U.S. Pat. No. 6,622,263, standard computers can be rendered fault tolerant without requiring any of the hardware or software customizations normally associated with fault-tolerant computers. All applications, host operating systems and input/output subsystems receive the benefit of fault tolerance without having to be modified in any way. BRIEF DESCRIPTION OF THE DRAWINGS The above and further advantages of the invention may be better understood by referring to the following description in conjunction with the accompanying drawings in which: FIG. 1 is a block schematic diagram of a generic memory-mapping scheme showing the mapping from the guest operating system's virtual addresses to its pseudo-physical addresses and from those addresses to actual physical addresses. FIG. 2 is a flowchart of the hypervisor's response to a request from a guest operating system for an I/O operation. FIG. 3 is a flowchart of the hypervisor's response to a request-complete message from an I/O device. FIG. 4 is a flowchart illustrating the process by which the hypervisor effects a checkpoint and preserves I/O integrity. FIG. 5 is a flowchart showing the procedure for implementing a rollback following a fault. DETAILED DESCRIPTION A hypervisor-based computer system is described that periodically captures and checkpoints relevant system-state information and, when used in concert with the checkpointing and fault-recovery procedures described in U.S. Pat. No. 6,622,263, can convert any standard computer running any standard operating system into a fault-tolerant computer. This state information is naturally segregated on a per-guest-operating-system basis and can be captured separately for each guest OS or captured simultaneously for the entire system as a whole. In the latter case, if the hypervisor also checkpoints its own state, the entire system can be rolled back, affording protection against faults encountered in running hypervisor code as well as those encountered by any of the guest operating systems. Used in this way, the methodology described in U.S. Pat. No. 6,622,263 covers hypervisor implementations in an obvious way, with the term “operating system” used in that disclosure replaced by “hypervisor” and the term “application” replaced by “guest operating system”. Consequently, the present invention focuses on the case in which each guest operating system is checkpointed independently of all the others and, following a fault, is rolled back to its last checkpoint and restarted without impacting those other guest operating systems. In this case, the state of the hypervisor itself is not checkpointed so no attempt is made to recover should the hypervisor encounter a bug in its own code. However, it should be obvious to anyone reasonably versed in the state of the art that both methods can be implemented simultaneously, giving the hypervisor the option recovering from a fault either by rolling back a single guest OS or, should that fail or the fault appear to be global in nature, by rolling back the entire system. Hypervisor modifications that support fault tolerance can be segregated into three basic components: 1. Memory management subsystem—responsible for managing physical memory and tracking modifications to it and for segregating it into partitions, some for use by guest operating systems and some for its own use. 2. Device emulator subsystem—responsible for managing virtual input/output (I/O) device emulators. The emulators present generic I/O devices to the guest operating systems. In many hypervisor implementations, these emulators are integrated into a virtual I/O processor (VIOP). 3. Checkpointing and recovery subsystem—implements the checkpoint and recovery operations required for fault tolerance. 1) Memory Management Subsystem The memory manager is the key hypervisor component for providing checkpointing support. Its primary function is to allocate physical memory not only to itself but also to the potentially multiple operating systems being hosted on the same computer. It presents to each guest operating system a block of memory that appears to be physically contiguous although it may in fact be composed of an arbitrary set of pages located anywhere in physical memory. As with all operating systems, the translation from virtual addresses to physical memory addresses is accomplished using a set of page tables. Hypervisor memory-manager subsystems, however, also manage, in addition to the normal physical page tables, a set of pseudo-physical page tables, here called the guest page tables, for each guest operating system. These page tables give the guest operating system the illusion that it is managing physical memory, but they are mapped into memory as read-only so that any modification to them can be reflected in the physical page tables managed by the hypervisor itself. The hypervisor memory manager also maintains a page database, including information about the user of that page (guest operating system, I/O subsystem, etc.), whether the page is read-only, and, if the processor supports multiple page sizes, the size of the page and its decomposition into a set of smaller physical pages. An illustrative mapping from a virtual address used by an application to an address in physical memory is shown in FIG. 1 . The virtual address space 101 consists of a linear array of addresses used by each application to access physical memory and memory-mapped I/O locations. Each virtual address in that space is partitioned into several segments used to access successive levels in the virtual-to-physical mapping hierarchy. FIG. 1 shows a two-level map for translating virtual addresses into pseudo-physical page addresses combined with a second two-level map for translating pseudo-physical addresses into physical page addresses, but more or fewer levels may be used in an obvious extension of the mapping described here. The term “pseudo-physical address” is used here to denote the address into which the guest operating system maps the virtual address on question. (The term “guest address space” will be used to denote the pseudo-physical address space associated with a specific guest operating system.) The first segment of the virtual address ( 102 ) is a directory offset or pointer to a word stored in guest directory 105 ; the directory is a page stored in pseudo-physical memory at a location identified by the guest-directory base address 107 , which is loaded at by the guest operating system into a processor register dedicated to that purpose. This word is in turn the address of a second page, the guest page table 103 , also stored in pseudo-physical memory. The second segment of the virtual address ( 103 ) is a table offset that points to a word in that table called here the virtual or pseudo-physical address. In the absence of a hypervisor, the pseudo-physical address reached at this point would serve as the actual physical address of a page in physical memory. Instead, it is converted by the hypervisor into a true physical address using a second set of translation tables. Segment 108 of the pseudo-physical address is a directory offset that points to a word in a directory in physical memory pointed to by the physical-directory base address register 112 . This dedicated processor register is loaded by the hypervisor and is unique to each guest operating system. As before, the word thereby extracted from the directory is the address of a physical page table 111 ; the second segment ( 109 ) of the pseudo-physical address is a table offset that identifies the word in the page table containing the address of the desired page ( 114 ) in physical memory. The last segment of the virtual address ( 104 ) is a data offset that points to the data entry of interest. Note that if the guest directories and page tables have not previously been loaded into the processor's cache, they must be read from physical memory. The pseudo-physical addresses of those pages must therefore also be translated by hypervisor maps info physical addresses as previously described. The maps used to translate pseudo-physical to physical addresses reside in hypervisor space and are mapped into the hypervisor's virtual address space using still other page maps. Of will be noted that the pseudo-physical address does not use the full address width since the lower-order address bits are taken directly from the guest's virtual address; the remaining bits are used for, example, to identify read-only pages. The specific use of these bits is implementation dependent, but all implementations leave some of these bits undefined. One of these undefined bits is used in the present invention as described below. The major modification to the hypervisor's memory-management subsystem required to support checkpointing-is the implementation of an extension of the technique, described in U.S. Pat. No. 6,622,263, for ensuring that memory can be restored to its pre-rollback state following a fault. This involves the allocation of a bit, called a temporary-read-only bit, in each physical page address. This bit is set by the memory manager in each entry in the relevant directory whenever an operating system is invoked and again following the establishment of each operating system checkpoint. Any attempt to write to an address with the temporary-read-only bit set causes a trap to the memory manager. On response to such a trap, the memory manager first determines if the page being accessed is indeed read-only. If it is, the memory manager invokes the relevant page-fault handler. Of it is not read-only, the memory manager resets the temporary-read-only bit in the directory address in question, accesses the page table corresponding to that address and sets the temporary-read-only bit in each of its addresses except for the address of the data page being accessed. It then records the address of that page on a guest-OS-specific checkpoint address queue and, in the case of pre-image checkpointing, copies the page itself to a guest-OS-specific checkpoint data buffer. Optionally, temporary-read-only bit can also be used in the hypervisor's own virtual-to-physical map pages to enable the hypervisor to checkpoint its own state using the methodology described in U.S. Pat. No. 6,622,263. In this case, if a fault occurs in a guest OS context, the hypervisor rolls back the guest OS as described in the present invention. Of that should fail to correct the problem, or if a fault is encountered while the hypervisor itself is running, it then has the option of rolling back the entire system. 2) Device Emulator Subsystem The I/O subsystem in many hypervisors is implemented using virtual I/O processors (VIOPs). Preferably, the hypervisor is also capable of supporting dual VIOPs with each having interfaces to the same dual-ported controllers. This enables one VIOP to serve as a backup should the active VIOP sustain a non-recoverable fault (e.g., one of its attached physical controllers fails). Regardless of the specific I/O subsystem implementation, the hypervisor provides the guest operating systems with generic interfaces to each class of I/O device (e.g., disk, network, serial bus, parallel bus, display, etc.). Relatively minor modifications of these interfaces enable I/O operations to be handled correctly following a fault-induced rollback of the guest operating system that issued them. One of the major innovations of the invention is a means for preserving I/O buffers set up since the last checkpoint so that they can continue to be used following a fault. This makes it possible to recover from faults without having to restart in-process I/O operations after the system state has been rolled back to its last checkpointed state and without the need for separate physical I/O processors or specially modified I/O drivers. To make this possible, each of the I/O subsystem's device emulators establishes read- or write-buffers as the destination or source, respectively, of the data to be read from or written to the I/O device in question. On addition, it defines an I/O-request block that it places on a list of pending I/O requests (the “pending-I/O” list). Of the emulator serves as the interface to more than one physical device, it maintains separate lists for each such device. Two additional lists are maintained for each guest OS, one list for operations completed for that guest OS (the “completed-I/O” list) and one for operations the completion of which was acknowledged at the time of the last checkpoint (the “acknowledged-I/O” list). Finally, it also maintains a list of states associated with each device it emulates (the “device-state” list). There are various well-known procedures for managing such lists. For illustrative purposes, it will be assumed that the lists are structured as linked lists, with each item on the list containing the address of the previous item on the list, or an indication that it is at the head of the list, and the address of the next item on the list, or an indication that it is the last such item. (Device-specific pointers are used to indicate the addresses of the first and last items on the pending-I/O and device-state lists. Global pointers, accessible by all emulators, are used for the addresses of the last items on each guest OS's completed-I/O list. Each request block on the pending-I/O list contains the identification of the requestor as well as the details of request as extracted from the information submitted by the requestor, including the physical start address and the length of any buffer established for the I/O in the requestor's space. It also contains a pointer to the item on the device-state list indicating the state of the device of interest at the time the request was submitted. FIG. 2 is a flowchart showing the hypervisor's response to a request to write data to, or to read data from, an I/O device. Regardless of whether the request is for a read or a write, the hypervisor sets up a buffer of the appropriate length in its own virtual address space (step 201 ). Of the operation is for data to be read from an I/O device ( 202 ), the hypervisor defines a page map linking those virtual addresses to available physical addresses ( 203 ). If it is a write to an I/O device, the requestor has already generated the source data so the hypervisor defines a page map linking its buffer virtual addresses to the physical addresses containing the data ( 204 ). (The temporary-read-only bits in the hypervisor page maps are not set unless the state of the hypervisor itself is to be checkpointed.) If an attempt is made to write into one of the data pages reached through the guest's map for the first time since the last checkpoint (i.e., if some part of the page not actually part of the data buffer is written to for the first time) that page will be checkpointed in the normal way. After setting up the buffer, the hypervisor constructs the aforementioned request block ( 205 ) appending to it the starting virtual address of those buffers. It translates the I/O request into the appropriate driver-specific format using its own virtual addresses to define the source or destination of the data ( 203 ). Of the I/O command entails a driver state change ( 207 ), the emulator reflects that fact in a device-state block, links it to the device-state list and updates the end-of-list pointer ( 208 ). This status information is used to reestablish the driver's state should it be necessary to restart it, or a backup driver, following an I/O fault. The hypervisor then links the request block to the list of pending-I/O requests ( 209 ). While it is possible to release I/O requests between checkpoints and rely on higher-level communication protocols to accommodate the possibility that certain I/O events will need to be repeated or that others may be unexpectedly repeated, the higher checkpoint frequencies now practicable with state-of-the-art computer systems make it acceptable to delay releasing I/O requests until the next checkpoint takes place. Doing so relieves the higher-level protocols from having to account for such events. (Higher-level protocols must still be used, however, to resolve such ambiguities when an I/O-device or other failure causes pending I/Os to be resubmitted to a backup device either locally or on a remotely located computer.) Accordingly, step 209 stipulates placing the request block on the pending-I/O queue for that device, but delaying the release of the request until the next checkpoint. Similarly, when the requested I/O operation has been completed, the request block is moved to the completed-I/O list and the acknowledgement of that completion is passed on to the requesting guest at the time of the immediately following checkpoint. It should be noted, however, that disk read and write requests need not be synchronized with checkpoints. The technique described in U.S. Pat. No. 6,622,263 whereby disk access requests can be issued without waiting for a checkpoint is equally compatible with the current invention. The emulator's response to a message from the physical device indicating that a requested I/O has been completed is shown in FIG. 3 . It first compares the device-state address in the request block with the address of the head of the device-state list ( 301 ). If they agree ( 302 ), the device state recorded in the device-state block at the head of the list is the state that prevailed following the execution of the request. If they do not, the execution of the request changed the state of the device, so the oldest state on the list is no longer relevant. Accordingly, the oldest item on the list is delinked ( 303 ) and the pointer to the head of the list updated. The emulator then delinks the request block from its list of pending I/Os and links it to the completed-I/O list of the guest OS that generated the request ( 304 ). 3) Checkpointing and Recovery Subsystem FIG. 4 shows a flowchart illustrating the checkpointing procedure. The first step in the procedure (step 401 ) is for the hypervisor to force a context switch through which all processors running the guest OS to be checkpointed switch to the hypervisor state. The mechanism for doing this is implementation dependent but typically involves an interrupt or trap that is recognized by the relevant processors. The trigger for forcing this context switch is usually determined by the elapsed time since the last checkpoint, but other triggers, such as blockage on certain I/O events can be used in addition to the normal time-based triggers. Following the context switch, during which the internal state of each affected processor is dumped on the relevant process queue, all modified cache blocks are either flushed out to main memory or otherwise captured (see below). Depending on whether pre- or post-image checkpointing is used ( 402 ), the hypervisor then either simply resets the pointers into the checkpoint address and pre-image data page queues ( 403 ) or else copies the pages identified by the checkpointed addresses into shadow memory ( 404 ). As demonstrated in U.S. Pat. No. 6,622,263, this copying can optionally be done in background mode after normal processing resumes. If post-image checkpointing is being implemented, the processor caches do not need to be flushed if the processor implements any of the standard cache-coherency protocols that ensure that the most recently modified cache line is always sourced whenever it is accessed, regardless of where it physically resides. On this case, when each modified page is copied to shadow memory, any modified cache line in that page will be copied, even if it has not yet been moved back to main memory. Again depending on the specific processor implementation, it may be necessary to invalidate, or at least set the temporary-read-only bits, in the processor-resident virtual-to-physical address-translation buffers, usually called the translation-look-aside buffers (TLBs), at each checkpoint. This ensures that the first attempt to write to a page following the checkpoint will still result in the previously described trap even if that same page had an entry in the TLB prior to that checkpoint. Once the guest OS's state has thus been checkpointed, the hypervisor discards the list of acknowledged I/O operations ( 405 ) since the fact that these operations have been completed is now part of the guest's checkpointed state. It then sets up the environment needed to return the context to that of the guest operating system. This guest OS may or may not be given the same processing resources that it had when it was checkpointed, however, since the hypervisor can reallocate resources whenever the occasion demands. To set up the environment, the hypervisor scans the completed-I/O list associated with the guest OS to be invoked ( 406 ) and, if there are any request blocks on that list ( 407 ), examines the first such request ( 408 ). If it is a read request, the hypervisor then determines if the request involves any partially used pages ( 409 ). If it does, it copies the portions of those pages that correspond to the buffered data from the hypervisor's buffer pages to the corresponding locations in the guest's read buffer ( 410 ). Optionally, the hypervisor can copy the non-buffer portion of the corresponding guest page into the hypervisor's buffer page and then remap that page as the new guest page. This may represent a small performance improvement if the data buffer contents of the page in question exceed half the size of the page. On any case, the hypervisor then remaps all full buffer pages from its own space into the guest's space ( 411 ), thereby effectively filling the guest's read buffer with the requested information. If the request was for a write operation, the hypervisor simply unmaps the source pages from its own space ( 412 ), freeing up those virtual addresses for other uses. The source pages remain mapped into the guest OS's space. For both read and write operations, following the remapping of the data buffers, the hypervisor informs the requesting OS that the operation has been completed and moves the request block from the completed-I/O lost to the acknowledged-I/O list ( 413 ). This latter list is retained until the next checkpoint since the guest OS will have to be informed of the fact that the operation has been completed should it be roiled back before that information is part of its checkpointed state. The method for acknowledging the completion of the operation to the guest OS is implementation and device dependent, but typically involves an interrupt or trap directed to the guest OS. Once all I/O operations that were completed prior to the last checkpoint have been dealt with, the hypervisor releases all pending I/O requests (i.e., all those I/O requests generated since the last checkpoint) to the relevant device emulators ( 414 ), sets the temporary-read-only bits in the guest's page directory and institutes a context switch back the guest OS ( 415 ). The recovery procedure following a fault is shown in FIG. 5 . If pre-image checkpointing is being implemented ( 501 ), the hypervisor copies the checkpointed memory pages from checkpoint memory back to the locations indicated by the checkpointed addresses ( 502 ). If post-image checkpointing is used instead, it switches to the shadow memory ( 503 ). Depending on the specifics of the checkpointing scheme being implemented, it may simply remap the guest OS's pages to their shadow locations or, in the case of remote checkpointing, it may reallocate all resources associated with the guest OS to the backup computer. Also, depending on the implementation and the nature of the fault, it may reestablish the abandoned pages in the primary memory as the new shadow memory. After thus returning the guest OS back to its last checkpointed state, the hypervisor then relays acknowledgements for all I/O operations that were completed at the time of that checkpoint ( 504 ) and those that have been completed since that time ( 505 ). The latter acknowledgements are then moved to the acknowledged I/O list. At this point, the guest OS is ready to resume operation ( 503 ). If an I/O device fails, the device emulator resets that device to the state listed in the block at the head of the device-state list, thereby returning it to the state that prevailed at the time the request at the head of its pending-I/O request list was submitted. If then resubmits that request, and, in turn, the rest of the requests on the pending-I/O queue, if the device in question has a backup, either locally or, if remote checkpointing is being used, on some other computer (e.g., if the hypervisor supports dual VIOPs), the I/O operations can be restarted on the backup device. If the device is located on a different computer from the one running the guest OS in question, the device-state and pending-I/O request queues must also be sent to the backup computer whenever a new I/O request is submitted by that guest OS. These same modifications also make it possible to recover from a fault in the VIOP itself, either by restarting the VIOP (assuming the fault does not permanently disable an attached controller) or by switching to the dual VIOP and, in either event, returning the device emulators to the appropriate state as before and reissuing all pending I/O requests. In this case, higher-level protocols must be relied upon to cope with possibly repeated requests. As previously noted, the invention disclosed here is compatible with that disclosed in U.S. Pat. No. 6,622,263 enabling the hypervisor itself also to be checkpointed. If this is done and the entire system, as opposed to a single guest OS, is rolled back, some I/O operations may be interrupted and will have to be restarted as described in that disclosure.

While system-directed checkpointing can be implemented in various ways, for example by adding checkpointing support in the memory controller or in the operating system in otherwise standard computers, implementation at the hypervisor level enables the necessary state information to be captured efficiently while providing a number of ancillary advantages over those prior-art methods. This disclosure details procedures for realizing those advantages through relatively minor modifications to normal hypervisor operations. Specifically, by capturing state information in a guest-operating-system-specific manner, any guest operating system can be rolled back independently and resumed without losing either program or input/output (I/O) continuity and without affecting the operation of the other operating systems or their associated applications supported by the same hypervisor. Similarly, by managing I/O queues as described herein, rollback can be accomplished without requiring I/O operations to be repeated and I/O device failures can be circumvented without losing any I/O data in the process.

This application claims the benefit of Provisional application Ser. No. 60/071,754, filed Jan. 16, 1998. BACKGROUND OF THE INVENTION This invention relates to a non-destructive testing method for determining the texture of materials using ultrasonics. The word “texture” designates direction-dependent properties of materials. One direction-dependent property of particular interest is elastic anisotropy in polycrystalline materials that results from the non-random distribution of the crystallographic orientations of single grains. Crystallographic texture is described by an orientation distribution function (ODF). Information on ODF is usually obtained from pole figure X-ray diffraction and typically consists of thousands of diffraction data points. Conventional texture analysis of materials normally involves destructive testing. A small sample is cut off from a material and tested in a laboratory. In some cases, especially in production control, it is not necessary to determine the “whole” texture. In this case, it is possible to use a low-resolution texture analysis method which relies upon a strict correlation between some material physical properties such as, for example, elastic or magnetic properties, and crystallographic texture. By restricting the texture analysis to a low-resolution technique, it is possible to perform texture analysis in a non-destructive way that offers the possibility of on-line qualitv control inspection. Three different techniques for low-resolution texture analysis are known. A first technique consists of taking X-ray measurements of a material under test. A device, called an “On-Line Texture Analyzer”, designed and used for this purpose, irradiates a sample with an incident beam containing a continuous spectrum of wavelengths such as, for example, the X-ray bremsstrahlung spectrum. Characteristic pole-intensities of the sample are measured by energy-dispersive detectors detecting the X-ray bremsstrahlung spectrum transmitted through the sample material. However, this technique is limited to relatively small thicknesses of material. This limitation is due to strong X-ray attenuation and dispersion inside the polycrystalline material, and strict requirements for positioning of the X-ray source and detectors with respect to the texture of the material sample. A second technique consists of electromagnetic Barkhausen noise and dynamic magnetostriction measurements. However, this technique is limited to materials having strong magnetic anisotropy. A third technique is based on the measurement of a material's vibrational properties, such as an ultrasound velocity, which are known to be correlated with the material texture. Ultrasound velocity measurements have advantages over the first two techniques in that samples to be tested are not limited in thickness, and materials without strong magnetic anisotropy may be analyzed. A prior art ultrasonic method for low-resolution texture analysis of single-phase polycrystalline materials such as, for example, low-alloyed aluminum having a cubic structure and orthorhombic texture is depicted in FIG. 1 . This technique employs a pulse-echo method to determine three ultrasound absolute propagation velocities (with respect to the specimen coordinate system) propagating in the rolling, transverse, and normal directions. A single, short-duration, high-frequency ultrasound pulse 10 , generated by an ultrasonic transducer 12 , advances into a specimen 14 which has flat, parallel surfaces. Multiple reflections of ultrasound inside the specimen 14 results. A series of consecutive echos 16 (see FIG. 1A) with gradually decreasing amplitudes are generated. The echos 16 are received by the transducer 12 for calculation of the propagation velocity. The propagation velocity may be calculated using measurements of ultrasound round-trip path length and ultrasound round-trip time-of-flight. The round-trip path length may be determined as a doubled specimen thickness (L in FIG. 1) precisely measured in the direction of ultrasound propagation. The ultrasound time-of-flight may be measured as a time interval or period 17 between the leading edges of two consecutive echos 16 . The absolute propagation velocities, calculated as a ratio of round-trip path length to time-of-flight, are usually used to determine the elastic constants (fourth-order expansion coefficients of the elasticity matrix) which characterize the texture of the specimen 14 . However, the accuracy of time-of-flight measurements may vary substantially depending on a number of factors such as: ultrasound pulse frequency spectrum; pulse rise time, length and shape; transducer-to-specimen positioning and coupling; and frequency band, resolution and accuracy of the electronic receiving system. The accuracy of the time-of-flight measurements is especially critical for materials having a low elastic anisotropy factor such as, for example, low-alloyed aluminum. In order to obtain acceptable measurement accuracy, out-of-line laboratory measurements may be required. The prior art ultrasonic method for texture characterization may not be suitable for on-line texture analysis. SUMMARY OF THE INVENTION A method of on-line ultrasonic texture characterization of a sputtering target is provided. Texture characterization may be accomplished through analysis of an ultrasonic backscattering signal amplitude distribution. A broad-band, focused ultrasonic transducer generates a megacycle center frequency ultrasonic pulse having a wavelength in the range of the average grain size (in the direction of ultrasound propagation) of a sputtering target specimen. The ultrasonic pulse is introduced into the specimen at an incident angle normal to the surface of the specimen. Due to interaction of the ultrasonic pulse with the texture of the specimen, backscattering echoes are generated in a portion of the specimen located within the transducer focal zone. The backscatter region extends at least one grain layer beneath the specimen surface to a depth of several grain layers in thickness. The backscattering echoes propagate back to the transducer where the echoes are converted by the transducer into an electrical signal which is processed by a broad-band acquisition system. A maximum amplitude value of the backscattering signal is extracted from the processed data and stored in a memory of the acquisition system for future data analysis. Data analysis is performed using data graphical representation in the form of a histogram of “occurrences versus amplitude” where the amplitude is plotted along the x axis while the occurrences (counts for certain amplitude values) are plotted along the y axis. The histogram is compared with histograms for reference standards having known preferred crystallographic and grain orientation, grain size, and chemical composition. Therefore, it is an object of the invention to provide a method of ultrasonic on-line texture characterization. It is a further object of the invention to provide a method of on-line texture characterization including the step of generating an ultrasonic pulse with a wavelength in the range of the average grain size of a specimen material in the direction of ultrasound propagation. It is yet another object of the invention to provide a method of ultrasonic on-line texture characterization including the step of detecting an ultrasonic backscattering signal generated by interaction of an initial ultrasonic pulse with specimen material texture. A still further object of the invention is to provide a method of ultrasonic on-line texture characterization including the step of plotting the backscattering signal amplitude in the form of a histogram of “occurrences versus amplitude”, and comparing the histogram with similar histograms for materials having known preferred crystallographic and grain orientation, grain size, and chemical composition. Other objects of the invention will be apparent from the following description the accompanying drawings and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a prior art method of ultrasonic texture analysis; FIG. 1A is a schematic diagram showing the ultrasound echoes obtained by the prior art method shown in FIG. 1; FIG. 2 is a schematic diagram of a method of ultrasonic on-line texture characterization in accordance with the invention: FIG. 3 is an enlarged schematic view of the backscattering region of the sputtering target of FIG. 2 showing backscattering echoes propagating from grain boundaries; FIG. 4 is a histogram of “occurrences versus amplitude” obtained according to the method of the invention for a relatively isotropic “random” texture; FIG. 5 is an X-ray diffraction pole-figure proof for the data shown in FIG. 4; FIG. 6 is a histogram of “occurrences versus amplitude” obtained according to the method of the invention for an anisotropic material having a strong <100> preferred crystallographic orientation: FIG. 7 presents the X-ray diffraction pole-figure proof for the data shown in FIG. 6; FIG. 8 is a histogram of “occurrences versus amplitude” obtained in accordance with the method of the invention for a <100> single crystal; FIG. 9 is a plot of normalized intensity versus tilt angle alpha, <200> azimuthally averaged, for the sputtering target of FIGS. 4 and 5; FIG. 10 is a plot of normalized intensity versus tilt angle alpha, <200> azimuthally averaged, for the sputtering target of FIGS. 6 and 7; FIG. 11 is a plot of normalized intensity versus tilt angle alpha, <200> azimuthally averaged, for the <100> single crystal of FIG. 8; and FIG. 12 shows the correlation between ultrasonic backscattering amplitude and degree of <200> preferred orientation for the sputtering targets and single crystal of FIGS. 4 - 11 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning to FIGS. 2 and 3, there may be seen schematic diagrams illustrating the method of the instant invention. A single, short-duration, megahertz frequency range ultrasonic pulse 20 , is generated by a focused ultrasonic transducer 22 . The pulse 20 is directed at a material 24 such that the angle of incidence of the pulse 20 is normal to the surface 26 of the material 24 . A backscattering signal 28 originates in a backscattering region 32 . The backscattering region 32 is located inside a transducer focal zone 34 and has a depth extending from at least one grain layer beneath the surface 26 to a depth of several grain layers. Backscattering occurs as a result of acoustic, impedance (i.e., ultrasound velocity) mismatch at grain boundaries of adjacent grains. Due to a limited number of grain boundaries along the ultrasound path inside the backscattering region 32 , the backscattering signal 28 experiences less signal volume averaging than the reflected ultrasonic signal of the prior art (FIG. 1 ). At a nearly resonant mode of ultrasound propagation (i.e., the ultrasound wavelength is in the range of average grain size), the statistics of identical wave phase shift at the grain boundaries inside the backscattering region 32 will depend on the degree of preferred crystallographic orientation. The number of identical wave phase shifts increases with increasing degree of preferred crystallographic orientation. The increase in the number of identical phase shift occurrences is detected as an increase in the number of counts for identical backscattering amplitudes. As a result, a histogram of “occurrences versus amplitude” tends to shrink in width and stretch in height with increasing kurtosis of the histogram (FIG. 6 ). In contrast, for materials having more isotropic texture, the histogram of backscattering signal amplitude is broader and shorter due to more random phase shift distribution (FIG. 4 ). Turning now to FIGS. 4 and 6, there may be seen histograms of backscattering signal amplitudes obtained in accordance with the method of the invention for two different material specimens. The first material specimen used to produce the histogram given in FIG. 4 is of an isotropic random crystallographic orientation. The FIG. 6 histogram results from ultrasonic analysis, in accordance with the invention, of a strong <100> preferred crystallographic orientation. In both cases, the specimen materials comprise aluminum-0.5 weight percent copper alloy having equivalent-axed grain texture (crystallographic orientation) and grain sizes in the range of 0.26 millimeter to 0.38 millimeter. The ultrasonic transducer 22 used to obtain the histograms is a 15 megahertz spherical focalization transducer. The region for backscattering signal monitoring is specified by focusing the transducer on a flat bottom hole of 0.1 millimeter diameter located at a distance of two millimeters under the surface of the specimen material. Comparing FIG. 6 with FIG. 4, it may be seen that the less textured material of FIG. 6 exhibits a narrower and taller or more elongated histogram of backscattering signal amplitude than the material having more random texture as shown in FIG. 4 . The X-ray diffraction pole-figures of FIGS. 5 and 7 confirm the findings of the observed differences in the preferred crystallographic orientations of the two specimen-materials. It should be noted that the effects of isolated, minute flaws on the histograms can be discarded or ignored if the total number of data points acquired exceeds the number of flaw-related data points by three to five orders of magnitude. By way of comparison, the histogram for a single crystal of Al-0.5 wt % Cu alloy having a crystallographic orientation of <100> is shown in FIG. 8 . The histogram of FIG. 8 was also obtained using a 15 megahertz spherical focalization transducer focused on a flat bottom hole of 0.1 millimeter diameter located at a distance of two millimeters beneath the surface of the crystal. The histogram shows an amplitude variation for the single crystal of about 4.7%, and a peak of about 2,716 occurrences. Graphs of normalized intensity versus tilt angle alpha in degrees for a <200> azimuthally averaged X-ray beam for each of the samples of FIGS. 4, 6 , and 8 , may be seen in FIGS. 9, 10 , and 11 , respectively. FIG. 12 shows a plot of the normalized ultrasonic backscattering amplitudes versus the degree of preferred <200> intensity normalized (azimuthally averaged) for each of the three sample specimens. The plot in FIG. 12 shows that there is a linear correlation between the results obtained from the instant texture characterization analysis by ultrasonic backscattering means and a conventional X-ray diffraction pole-figure analysis method. For example, point 202 in FIG. 12 shows the normalized intensities for both the ultrasonic detection means (y-axis) and x-ray diffraction methods (x-axis) as applied to the isotropic random texture specimen with point 204 representing the x, y coordinate intensities found for the strong <100> preferred orientation sample. Point 206 represents the ultrasonic and x-ray diffraction intensities for the single crystal material tested. Thus, the instant method of ultrasonic on-line texture characterization analysis yields good results when compared with standard out-of-line measurement techniques since there is a clear linear relationship between the two methods. It is to be noted that the ultrasonic pulse to be applied to the sputter target may be applied through a fluid medium such as air or water. Presently, it is preferred to place the sample in a water immersion tank to thereby apply the pulse through water. Typically, the transducer will be located at normal incidence to the specimen surface. The pulse or burst of MHz-range frequency electrical signal is generated by an electronic pulser tuned to the frequency range of the ultrasonic transducer (11-18.5 MHz). This signal is converted by the transducer into an ultrasound pulse. The ultrasound pulse propagates through the water (which is a couplant) at a normal incidence to the specimen surface. As a result of the interaction of the ultrasonic pulse with the exposed volume of the specimen (approximately 5 mm deep into the specimen measured from the top surface) part of the ultrasonic energy is scattered back to the transducer in the form of an echo. The exposed area is situated inside the transducer focal zone (−6 dB). When the echo arrives, the transducer electronically switches from an electronic transmitter to a gated electronic receiver. The echo is received at the transducer about 60 microseconds after the pulse is sent. The returned RF signal (the ultrasonic echo) is captured inside the gate of a low noise gated preamplifier. The pre-amplified RF echo is passed to the low noise linear amplifier. The echo acquisition system includes: the low noise gated preamplifier; the low noise linear amplifier with a set of calibrated attenuators; and a 12-bit ADC (2,44 mV/bit) and a PC equipped with a printer. The linearly amplified analog RF echo signal is digitized by the 12-bit ADC (2, 44 mV/bit) and passed in digital form to the PC. The maximum value of the digitized RF signal is stored in the memory of the PC software. This maximum value is used for texture analysis. The texture analysis device shown in FIG. 2 uses an immersion tank filled with DI water. It is equipped with a mechanical X-Y scanner, electronic pulser-receiver instrument and transducer assembly mechanically attached to the X-Y scanner. The mechanical X-Y scanner is controlled by a PC based electronic controller. The X-Y scanning unit performs a meander-like stepwise motion with short steps in the X direction and longer steps in the Y direction. Data acquisition steps in both X and Y directions were chosen to equal 0.8 mm to provide a detection of 0.1 mm flat bottom hole at detection level (9-6 dB) without exposure area overlapping. The preferred transducer is sold by Panametrics, USA under the model V 319 designation. This is a high resolution piezoelectric transducer having a focalization distance of 51 mm and 12.5 mm in diameter with a center frequency of 15 MHz and 7.2 MHz bandwidth (-6 dB). In detecting the backscatter echo, software available from Structural Diagnostics, Inc. under the designation SDI-5311 can be used. Before testing, the specimen surface should be prepared via diamond cutting or the like. Usually, the texture characterization is performed for the entire area of the target, usually 7.5 in.×7.5 in. For texture analysis, about 50,000-500,000 raw data points are analyzed. The velocity of the ultrasonic pulses propagating from the target is commonly on the order of about 6.29-6.35×10 −1 cm/microsecond. While the method herein described, and the form of apparatus for carrying this method into effect, constitutes a preferred embodiment of this invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be made in either without departing from the scope of the invention, which is defined in the appended claims.

A sputtering target ( 24 ) under test is irradiated with an ultrasonic pulse ( 20 ). The ultrasonic pulse ( 20 ) has a wavelength in the sputtering target ( 24 ) in the range of the average grain size for the target ( 24 ) under test. Backscattering echoes ( 28 ) are produced by the interaction of the pulse ( 20 ) with grain boundaries in the target ( 24 ) under test. The backscattering echoes ( 28 ) are detected and a representative electrical signal is generated. The number of occurrences of the backscattering echoes ( 28 ) having amplitudes within predetermined ranges are determined. A histogram of the number of occurrences versus amplitude is plotted. The histogram for the target ( 24 ) under test is compared with reference histograms for sputtering targets having known crystallographic orientations to determine the texture of the target ( 24 ) under test.

FIELD OF THE INVENTION AND RELATED ART [0001] The present invention relates to a process cartridge made up of an electrophotographic photosensitive drum and a development roller (which processes photosensitive drum), in particular, a process cartridge, the electrophotographic photosensitive drum and development roller of which can be placed in contact with, or separated from, each other. The present invention also relates to an electrophotographic image forming apparatus employing the above described process cartridge. [0002] In recent years, a process cartridge system has come to be widely used in the field of an image forming apparatus which uses an electrophotographic image forming process. A process cartridge system is one of the electrophotographic image forming systems. It uses a cartridge in which an electrophotographic photosensitive drum, and a development roller, that is, a roller for processing an electrophotographic photosensitive drum, are integrally disposed to make them removably mountable in the main assembly of an image forming apparatus. Thus, the employment of a process cartridge system makes it possible for a user to maintain an electrophotographic image forming apparatus without relying on a service person. This is why a process cartridge system has come to be widely used in the field of an electrophotographic image forming apparatus. [0003] A process cartridge is structured so that its development roller is kept pressured toward its electrophotographic photosensitive drum with the application of a preset amount of pressure, in order to keep the development roller in contact with the photosensitive drum when forming an image. In a case of a so-called contact development method, that is, a development method which places a development roller in contact with a photosensitive drum to develop a latent image on the photosensitive drum, the elastic layer of the development roller is kept pressed upon the peripheral surface of the photosensitive drum so that a preset amount of contact pressure is maintained between the peripheral surface of the development roller and that of the photosensitive drum. [0004] Therefore, if a process cartridge is left unused in the main assembly of an image forming apparatus for a substantial length of time, the elastic layer of the development roller sometimes deforms. Thus, if an image forming apparatus in which a process cartridge has been left unused for a substantial length of time is used for the first time thereafter, it is possible that a latent image will be nonuniformly developed. Further, in the case of a so-called contact development method, a development roller is in contact with a photosensitive drum during development. Therefore, developer sometimes transfers from a development roller onto the points of the peripheral surface of a photosensitive drum, to which developer is not supposed to adhere. Further, not only do a photosensitive drum and a development roller rotate in contact with each other during development, but also, during processes other than development. Therefore, a so-called contact development method exacerbates the deterioration of a photosensitive drum, a development roller, and developer. [0005] One of the solutions to the above described problem is proposed in Japanese Laid-open Patent Application 2003-167499. According to this patent application, an image forming apparatus is provided with a mechanism which acts on a process cartridge to keep an electrophotographic photosensitive drum and a development roller separated from each other when an image is not actually being formed (Patent Document 1). [0006] In the case of the image forming apparatus proposed in Patent Document 1, its main assembly is structured so that four process cartridges are removably mountable in the main assembly. Each cartridge is made up of a photosensitive member unit and a development unit. The photosensitive member unit has a photosensitive member. The development unit supports a development unit, and is connected to the photosensitive member unit so that it can be rotationally moved relative to the photosensitive member unit. Further, the main assembly of the image forming apparatus is provided with a separation plate, whereas the process cartridge is provided with a force receiving portion. As the separation plate is moved, the force receiving portion receives the force from the separation plate, causing the development unit to move relative to the photosensitive member unit. As a result, the development roller, which was in contact with the photosensitive drum, separates from the photosensitive drum. [0007] According to the prior art, the force receiving portion, that is, the portion which catches the force for separating a development roller and a photosensitive member from each other, remains projecting beyond the external contour of the development unit. Therefore, it is liable to be damaged while a user handles a process cartridge, or a process cartridge is conveyed alone. Further, the presence of the above described force receiving portion has been one of the major problems which arose when studies were made to reduce in size a process cartridge structured so that its electrophotographic photosensitive member and development roller can be placed in contact with, or separated from, each other, and also, when studies were made to reduce in size the main assembly of an image forming apparatus in which such a process cartridge as the one described above is removably mountable. SUMMARY OF THE INVENTION [0008] The primary object of the present invention is to provide a process cartridge, the electrophotographic photosensitive drum and development roller of which can be placed in contact with, or separated from, each other, and which is significantly smaller in size than a counterpart in accordance with the prior art, and also, to provide an electrophotographic image forming apparatus which is compatible with a process cartridge in accordance with the present invention, is removably mountable and is significantly smaller in size than a counterpart in accordance with the prior art. [0009] Another object of the present invention is to provide a process cartridge, the electrophotographic photosensitive member and development roller of which can be placed in contact with, or separated from, each other, and the development unit moving force receiving portion of which is significantly less liable to be damaged while the process cartridge is handled by a user, or transported alone, than a counterpart in accordance with the prior art. [0010] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS [0011] FIG. 1 is a schematic sectional view of the electrophotographic image forming apparatus in the first embodiment of the present invention, showing the general structure of the apparatus. [0012] FIG. 2 is a schematic sectional view of the process cartridge in the first embodiment of the present invention. [0013] FIG. 3 is also a schematic sectional view of the electrophotographic image forming apparatus in the first embodiment of the present invention, showing the general structure of the apparatus. [0014] FIG. 4 is another schematic sectional view of the electrophotographic image forming apparatus in the first embodiment of the present invention, showing how the process cartridges therein are replaced. [0015] FIG. 5 is a schematic sectional view of one of the process cartridges, and its adjacencies, in the electrophotographic image forming apparatus in the first embodiment of the present invention, at a plane perpendicular to the axial line of the photosensitive drum. [0016] FIG. 6 is a schematic sectional view of the process cartridge in the first embodiment of the process cartridge, showing the movement of the structural components of the cartridge, which is related to the mounting of the process cartridge into the apparatus main assembly. [0017] FIG. 7 is a schematic side view (as seen from the side from which it receives cartridge driving force) of the process cartridge in the first embodiment of the present invention, which is being mounted into the apparatus main assembly, showing the movement the structural components of the cartridge, which is related to the mounting of the process cartridge into the apparatus main assembly. [0018] FIG. 8 is also a schematic sectional view (as seen from the side from which it receives cartridge driving force) of the process cartridge in the first embodiment of the present invention, which is being mounted into the apparatus main assembly, showing the movement of the structural components of the cartridge, which is related to the mounting of the process cartridge into the apparatus main assembly. [0019] FIG. 9 is an exploded perspective view of the process cartridge in the first embodiment of the present invention. [0020] FIG. 10( a ) is a perspective view of the process cartridge in the first embodiment of the present invention, as seen from the side from which the cartridge is driven, and FIG. 10( b ) is a perspective view of the process cartridge in the first embodiment of the present invention, as seen from the side opposite from the side from which the cartridge is driven. [0021] FIG. 11 is a perspective view of the process cartridge in the first embodiment of the present invention, as seen from the side from which the cartridge is driven. [0022] FIG. 12 is a schematic drawing of the process cartridge in the second embodiment of the process cartridge, showing the movement of the structural components of the cartridge. [0023] FIG. 13 is an exploded perspective view of the process cartridge in the second embodiment of the present invention. [0024] FIG. 14 is a schematic drawing of the process cartridge in the third embodiment of the process cartridge, showing the movement of the structural components of the cartridge, which is related to the mounting of the process cartridge into the apparatus main assembly. [0025] FIG. 15 is an exploded perspective view of the process cartridge in the third embodiment of the present invention. [0026] FIG. 16 is a schematic drawing of the cartridge tray guiding hole of the electrophotographic image forming apparatus in the first embodiment of the present invention. [0027] FIG. 17 is a partially cutaway perspective view of the electrophotographic image forming apparatus in the first embodiment of the present invention. [0028] FIG. 18 is a schematic drawing of the pressing member, and the components related to the operation of the pressing member, in the first embodiment of the present invention, showing the movement of the pressing member. [0029] FIG. 19 is a schematic drawing of the force applying first member, and the components related to the operation of the force applying first member, in the first embodiment of the present invention, showing the operation of the force applying first member. [0030] FIG. 20 is a perspective view of the force receiving apparatus of the process cartridge in the first embodiment of the present invention. [0031] FIG. 21 is a schematic drawing of the process cartridge in the first embodiment of the present invention, the force receiving second member of which has been just been moved by the force applying second member of the cartridge. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 [0032] Next, referring to FIGS. 1-4 , the process cartridges and electrophotographic image forming apparatuses in this preferred embodiment of the present invention will be described. [0033] FIG. 1 is a schematic sectional view of the electrophotographic image forming apparatus 100 (which hereafter will be referred to simply as apparatus main assembly), in which multiple (four) process cartridges 50 y, 50 m, 50 c, and 50 k (which hereafter may be referred to simply as cartridges 50 ) which have been removably mounted. The multiple (four) cartridges 50 store yellow, magenta, cyan, and black toners (developers), one for one. FIG. 2 is a schematic sectional view of the cartridge itself. FIGS. 3 and 4 are schematic sectional drawings of the electrophotographic image forming apparatus in this embodiment, which are for showing how the any cartridge or cartridges 50 are removed from the main assembly of the image forming apparatus. {General Structure of Electrophotographic Image Forming Apparatus} [0034] The electrophotographic image forming apparatus in this embodiment is structured to carry out the following image forming operation. Referring to FIG. 1 , first, the uniformly charged area of the peripheral surface of each of the electrophotographic photosensitive drums (which hereafter will be referred to as photosensitive drums) 30 y, 30 m, 30 c, and 30 k is scanned by a beam of laser light 11 projected by a laser scanner 10 , with which the apparatus main assembly 100 is provided, while being modulated with pictorial signals. As a result, an electrostatic latent image is effected on the peripheral surface of each photosensitive drum 30 . This electrostatic latent image is developed by a development roller 42 , into a visible image; an image is formed of toner (developer) on the peripheral surface of the photosensitive drum 30 . In other words, yellow, magenta, cyan, and black toner images are formed on the photosensitive drums 30 y, 30 m, 30 c, and 30 k, respectively. Then, these toner images are sequentially transferred by the voltages applied to transfer rollers 18 y, 18 m, 18 c, and 18 k, onto a transfer belt 19 supported and stretched by rollers 20 - 22 . Thereafter, the toner images on the transfer belt 19 are transferred by a transfer roller 3 , onto a sheet of recording medium P delivered by a recording medium conveyance roller 1 as a recording medium conveying means. Then, the recording medium P is conveyed to a fixation unit 6 made up of a driver roller, and a fixation roller having an internal heater. In the fixation unit 6 , heat and pressure is applied to the recording medium P and the toner images thereon. As a result, the toner images on the recording medium P are fixed to the recording medium P. Then, the recording medium P is discharged onto a delivery tray 9 by a pair of discharge rollers 7 . {General Structure of Process Cartridge} [0035] Next, referring to FIGS. 1 , 2 and 10 , the cartridges 50 in this embodiment will be described. The multiple (four) cartridges 50 in this embodiment are the same in structure although they are different in the color of the toner T they store. Thus, the structure of the cartridges 50 will be described with reference to the cartridge 50 y. [0036] The cartridge 50 y is provided with a photosensitive drum 30 , and processing means which process the photosensitive drum 30 . The processing means in this embodiment are a charge roller 32 which is the charging means for charging the photosensitive drum 30 , a development roller 42 which is the developing means for developing a latent image formed on the photosensitive drum 30 , a blade 33 which is the cleaning means for removing the residual toner remaining on the peripheral surface of the photosensitive drum 30 , etc. The cartridge 50 y is made up of a drum unit 31 and a development unit 41 . {Structure of Drum Unit} [0037] Referring to FIGS. 2 and 10 , the drum unit 31 includes the abovementioned photosensitive drum 30 , charge roller 32 , and blade 33 . It also includes a waste toner storing portion 35 , a drum unit main frame 34 , and lateral covers 36 and 37 (which hereafter will be referred to simply as cover). Referring to FIG. 9 , one of the lengthwise end portions of the photosensitive drum 30 is rotatably supported by the supporting portion 36 b of the cover 36 , whereas the other lengthwise end of the photosensitive drum 30 is rotatably supported by the supporting portion 37 b of the cover 37 as shown in FIGS. 10( a ) and 10 ( b ). The covers 36 and 37 are attached to the lengthwise ends of the drum unit main frame 34 . Next, referring to FIG. 10( b ), the lengthwise end portion of the photosensitive drum 30 , which is supported by the cover 36 , is provided with a coupling member 30 a for transmitting driving force to the photosensitive drum 30 . The coupling member 30 a engages with a first coupling member 105 of the apparatus main assembly 100 , shown in FIGS. 4 and 7 , as the cartridge 50 y is mounted into the apparatus main assembly 100 . Thus, as driving force is transmitted from a motor (unshown) with which the apparatus main assembly 100 is provided, to the coupling member 30 a, the photosensitive drum 30 rotates in the direction indicated by an arrow mark U in FIG. 2 . The charge roller 32 is supported by the drum unit main frame 34 so that it is rotated in contact with the photosensitive drum 30 by the rotation of the photosensitive drum 30 . The blade 33 is supported also by the drum unit main frame 34 so that it remains in contact with the peripheral surface of the photosensitive drum 30 with the presence of a preset amount of pressure between the blade 33 and the peripheral surface of the photosensitive drum 30 . The covers 36 and 37 are provided with holes 36 a ( FIG. 9) and 37 a ( FIGS. 10( b )) for supporting the development unit 40 in such a manner that the development unit 40 is rotationally movable relative to the drum unit 31 . {Structure of Development Unit} [0038] Referring to FIGS. 2 and 9 , the development unit 41 has the abovementioned development roller 42 . It also has a development blade 43 , a development unit main frame 48 , a bearing unit 45 , and a pair of lateral covers 46 . The development unit main frame 48 has a toner storage portion 49 in which the toner to be supplied to the development roller 42 is stored. It supports the development blade 34 which regulates the thickness to which toner is coated on the peripheral surface of the development roller 42 . Referring to FIG. 9 , the bearing unit 45 is firmly attached to one of the lengthwise end portions of the development unit main frame 48 . It rotatably supports the development roller 42 , one of the lengthwise end portions of which has a development roller gear 69 . Further, the bearing unit 45 is provided with an idler gear 68 , which transmits driving force from a coupling member 67 to the development roller bear 69 . The cover 46 is securely attached to the outward side of the bearing unit 45 , in terms of the lengthwise direction of the bearing unit 45 , in a manner to cover the coupling member 67 and idler gear 68 . Further, the cover 46 is provided with a cylindrical portion 46 b, which protrudes outward from the outward surface of the cover 46 . The coupling member 67 is exposed through the hollow of the cylindrical portion 46 b. The apparatus main assembly 100 and process cartridge 50 y are structured so that as the process cartridge 50 y is mounted into the apparatus main assembly 100 , the coupling member 67 engages with the second coupling 106 of the apparatus main assembly 100 , which is shown in FIG. 17 , transmitting thereby driving force from the motor (unshown) with which the apparatus main assembly 100 is provided, to the process cartridge 50 y. {Connection of Development Unit to Drum Unit} [0039] Referring to FIGS. 9-11 , the development unit 41 and drum unit 31 are connected in the following manner: First, at one end of the process cartridge 50 y, the cylindrical portion 46 b is fitted into the supporting hole 36 a. At the other end, a projection 48 b which projects from the development unit main frame 48 is fitted into the supporting hole 37 a. As a result, the development unit 41 is connected to the drum unit 31 in such a manner that the development unit 41 is rotationally movable relative to the drum unit 31 . Next, referring to FIG. 2 , the development unit 41 is kept pressured by a pair of compression springs 95 , which are elastic members, in the direction to be rotated about the axial line of the cylindrical portion 46 b so that the development roller 42 is kept in contact with the photosensitive drum 30 . That is, the development unit 41 is kept pressed by the resiliency of the compression springs 95 in the direction indicated by a narrow mark G, generating a moment H which acts in the direction to rotate the development unit 41 about the cylindrical portion 46 b and projection 48 b. Thus, the development roller 42 is kept in contact with the photosensitive drum 30 with the presence of the preset amount of contact pressure between the development roller 42 and photosensitive drum 30 . The position in which the development unit 41 is when it is kept in contact with the photosensitive drum 30 is referred to as “contact position”. [0040] Referring to FIG. 10( a ), the compression spring 95 in this embodiment is located on the opposite side from one of the lengthwise end portions, where the coupling member 30 a of the photosensitive drum 30 , and the coupling member 67 which transmits driving force to the development roller gear 69 , are located. {Force Receiving Apparatus} [0041] Referring to FIG. 2 , the cartridge 50 y is provided with a force receiving apparatus 90 for placing the development roller 42 and photosensitive drum 30 in contact with each other, or separating them from each other, in the apparatus main assembly 100 . [0042] Referring to FIGS. 6 and 8 , which are schematic side views of the cartridge 50 y, the cover 36 of which has been removed, as seen from the side from which the cartridge 50 y is driven, the force receiving apparatus 90 is made up of a force receiving first member 71 and a force receiving second member 70 . Until the cartridge 50 y begins to be positioned relative to the apparatus main assembly 100 in a preset manner, the force receiving second member 70 remains in its standby position, that is, the position in which the force receiving second member 70 does not project beyond the external contour of the cartridge 50 y, as shown in FIG. 10( a ). As the cartridge 50 y is advanced into the apparatus main assembly 100 in the direction indicated by an arrow mark Z 2 (shown in FIG. 1) by a cartridge tray 13 (which will be described later), the cartridge 50 y is positioned in the apparatus main assembly 100 by a cartridge positioning portion 101 a of the apparatus main assembly 100 . As the cartridge 50 y is pressed against the cartridge positioning portion 101 a, the force receiving first member 71 is pressed upward by a projection 180 (force receiving first member pressing member) of the apparatus main assembly 100 , which will be described later. That is, the force receiving first member 71 receives a first external force from the projection 180 . As a result, the force receiving portion 70 is moved out of its standby position, projecting outward of the cartridge 50 y beyond the external contour of the cartridge 50 y, as shown in FIG. 11 . [0043] Next, referring to FIGS. 6 , 7 , and 9 , while the cartridge 50 y is kept in its accurate positioned (image forming position) in the apparatus main assembly 100 by the positioning portion 101 a, the force receiving first member 71 is below the force receiving second member 70 . The force receiving first and second members 71 and 70 are in connection with each other. More specifically, the force receiving second member 70 is rotatably supported by its rotational axle 70 b, and is provided with an elongated hole 70 a. The top end portion (in drawings) of the force receiving first portion 71 is provided with a projection (connective pin), which is fitted in the elongated hole of the force receiving second member 70 . Thus, as force is applied to the force receiving second member 70 by the force receiving first member 71 , more specifically, the projection (connective pin) of the force receiving first member, which is in the elongated hole 70 a of the force receiving second member 70 , the force receiving first member 70 is rotationally moved about its rotational axle 70 b. [0044] Referring to FIG. 7 , since the elongated hole 70 a is located between the rotational axle 70 b and the force catching surface 70 c, a distance h 2 by which the force receiving second member 70 moves can be made greater than a distance h 1 ( FIG. 7 ) by which the force receiving first member 71 moves, by properly setting the leverage ratio of the force receiving second member 70 . Here, the distances by which the force receiving first and second members 71 and 70 move are the distances measured in terms of the vertical direction, that is, the direction parallel to the direction in which the force receiving member 71 is moved toward the force applying member 60 (which will be described later). That is, with the employment of the above described structural arrangement, the distance h 2 by which the force receiving second member 70 moves can be increased without increasing the projection 180 in the distance by which it projects, making it thereby possible to reduce in size the apparatus main assembly 100 shown in FIG. 1 . Incidentally, the force receiving apparatus is movably supported by the cover 46 . {Cartridge Tray of Electrophotographic Image Forming Apparatus Main Assembly} [0045] Next, the cartridge tray 13 , which is in the form of a drawer, will be described. [0046] Referring to FIG. 4 , the cartridge tray 13 is attached to the apparatus main assembly 100 in such a manner that, in practical terms, it can be horizontally and linearly moved relative to the apparatus main assembly 100 . That is, the cartridge tray 13 can be pushed into, or pulled out of, the apparatus main assembly 100 in the direction indicated by an arrow mark Z 2 or Z 1 , respectively. The apparatus main assembly 100 is structured so that the cartridge tray 13 can be locked in the innermost position (image forming position, shown in FIG. 1 , in the apparatus main assembly 100 ), and the outermost position (cartridge replacement position: cartridge mounting or removing position), shown in FIG. 4 , which is the farthest position to which the cartridge tray 13 can be pulled out). The cartridge 50 is mounted into the cartridge tray 13 by an operator in the direction indicated by an arrow mark C, which is virtually parallel to the direction of gravity, as shown in FIG. 4 . The cartridge tray 13 is structured so that as the cartridges 50 are mounted into the cartridge tray 13 , the cartridges 50 become arranged in tandem, in the direction parallel to the direction in which the cartridge tray 13 is movable, with their lengthwise direction (which is parallel to axial lines of photosensitive drum 30 and development roller 42 ) being perpendicular to the moving direction of the cartridge tray 13 . As the cartridge 13 is pushed into the apparatus main assembly 100 , the cartridges 50 in the cartridge tray 13 enter the apparatus main assembly 100 , with the presence of a preset amount of gap f 2 ( FIG. 5 ) between the photosensitive drum 30 in each cartridge 50 , and an intermediary transfer belt 19 located below the cartridge path. Then, as the cartridge tray 13 is moved into its innermost position in the apparatus main assembly 100 , each cartridge 50 is positioned in the apparatus main assembly 100 by the cartridge positioning portion 101 a provided in the apparatus main assembly 100 ( FIGS. 5 and 7 ). The cartridge positioning operation will be described later in detail. A user is to close a door 12 after pushing the cartridge tray 13 all the way into the apparatus main assembly 100 . Closing the door 12 ensures that each cartridge 50 is properly mounted into the apparatus main assembly 100 . Therefore, in terms of operability, this structural arrangement for the apparatus main assembly 100 and cartridges 50 is superior to the structural arrangement of an electrophotographic image forming apparatus in accordance with the prior art, which requires the cartridges 50 to be individually mounted into the apparatus main assembly 100 by a user. [0047] Next, referring to FIGS. 1 , 3 , 4 , and 17 , the operation of the cartridge tray 13 will be described. FIG. 17 does not show the cartridges 50 , in order to make it easier to understand the operation of the cartridge tray 13 . [0048] The cartridge tray 13 is supported by a pair of tray supporting members 14 in such a manner that the cartridge tray 13 can be pulled out of the apparatus main assembly 100 while remaining supported by the tray supporting members 14 . The tray supporting members 14 are moved by the movement of the door 12 , which can be opened or closed by an operator (user). The door 12 is attached to the apparatus main assembly 100 so that it can be rotationally moved about its rotational axis 12 a. The door 12 is rotationally movable between a position (shut position) in which it completely covers an opening 80 , as shown in FIG. 1 , and a position (open position) in which it fully exposes the opening 80 as shown in FIG. 3 . [0049] When it is necessary to take out any cartridge or cartridge 50 in the apparatus main assembly 100 , the door 12 is to be rotationally moved from the shut position to the open position. As the door 12 is rotationally moved, a pair of projections 15 (connective pins) with which the door 12 is provided moves in the clockwise direction about the rotational axis 12 a, while moving in a pair of elongated holes 14 c, one for one, with which the tray supporting member 14 is provided, from the bottom end of the elongated hole 14 c toward the top end of the elongated hole 14 c, as shown in FIG. 3 . As a result, the tray supporting members 14 are moved by the projections 15 in the direction indicated by the arrow mark Z 1 . As the tray supporting members 14 are moved in the abovementioned direction, the projections 14 d 1 and 14 d 2 , which project from each of the tray supporting members 14 are guided by the guiding holes 107 with which the apparatus main assembly 100 is provided, as shown in FIG. 4 . Referring to FIG. 16 , each guiding hole 107 has three sections, that is, two horizontal sections 107 a 1 and 107 a 3 , and one diagonal section 107 a 2 . The diagonal section 107 a 2 extends diagonally upward from the horizontal section 107 a 1 to the horizontal section 17 a 3 . Therefore, as the door 12 is moved from the shut position, shown in FIG. 1 , to the open position, shown in FIG. 3 , the projections 14 d 1 and 14 d 2 are guided by the guiding hole 107 , sequentially through the horizontal portion 107 a 1 , diagonal portion 107 a 2 , and horizontal portion 107 a 3 . Thus, the tray supporting members 14 are first moved in the direction indicated by the arrow mark Z 1 , and then, are moved in the direction indicated by an arrow mark Y 1 , that is, direction to move away from the transfer belt 19 . With the tray supporting members 14 moved all the way in the direction indicated by the arrow mark Y 1 , the cartridge tray 13 can be pulled out of the apparatus main assembly 100 through the opening 80 in the direction indicated by the arrow mark Z 1 , as shown in FIG. 4 . FIG. 17 is a partially cutaway perspective view of the image forming apparatus after the cartridge tray 13 has been pulled out of the apparatus main assembly 100 to its outermost position. [0050] Next, the case in which any cartridge or cartridges 50 are mounted into the apparatus main assembly 100 will be described. Referring to FIG. 4 , the cartridge tray 13 is to be pushed into the apparatus main assembly 100 in the direction of the arrow mark Z 2 through the opening 80 , with the door 12 kept in the open position. Thereafter, the door 12 is to be moved into the shut position as shown in FIG. 2 . As the door 12 is moved, each of the projection 15 of the door 12 moves in the counterclockwise direction about the rotational axis 12 a, while moving in the corresponding elongated hole 14 c of the tray supporting member 14 , toward the bottom end 14 c 2 of the elongated hole 14 c, as shown in FIG. 1 . Thus, the tray supporting member 14 is moved in the direction of the arrow mark Z 2 by the pair of projections 15 . Therefore, as the door 12 is moved into the shut position as shown in FIG. 1 , the projections 14 d 1 and 14 d 2 ( FIG. 4 ) are guided by the horizontal portion 107 a 1 , diagonal portion 107 a 2 , and horizontal portion 107 a 3 , in the listed order, as shown in FIG. 16 . Therefore, the tray supporting members 14 move, first, in the direction of the arrow mark Z 2 , and then, in the direction of the arrow mark Y 2 , that is, the direction to move closer to the transfer belt 19 , as shown in FIG. 1 . {Positioning of Process Cartridge Relative to Electrophotographic Image Forming Apparatus Main Assembly} [0051] Next, referring to FIGS. 5 , 17 , and the positioning of the cartridge 50 in the apparatus main assembly 100 will be described. Referring to FIG. 17 , the apparatus main assembly 100 is provided with multiple pairs (four pairs in this embodiment) of cartridge positioning portions 101 a for positioning a cartridge 50 relative to the apparatus main assembly 100 . That is, each cartridge compartment of the cartridge tray 13 is provided with a pair of cartridge positioning portions 101 a, which are located at the lengthwise ends of the corresponding compartment, one for one, in terms of the direction parallel to the lengthwise direction of the cartridge 50 , in a manner to sandwich the transfer belt 19 . Referring to FIGS. 18 ( a ) and 18 ( b ), there are pressing members 61 ( 61 y, 61 m, 61 c, and 61 k ) above each of the tray supporting members 14 . Each pressing member 61 is provided with a hole 61 d, through which a pressing member supporting shaft 55 , with which the apparatus main assembly 100 is provided, is put to rotatably support the pressing member 61 . [0052] Referring again to FIGS. 18( a ) and 18 ( b ), as the door 12 is moved from the open position to the shut position (in X direction), the pressing member 61 is moved in the direction indicated by an arrow mark Z, pressing thereby on the top surface of the drum unit main frame 34 as shown in FIG. 20 . Therefore, the cartridge 50 y is pressed in the direction indicated by an arrow mark P in FIG. 7 , causing the cartridge positioning portion 31 b, with which the drum unit 31 y is provided, to come into contact with the cartridge positioning portion 101 a of the apparatus main assembly 100 . As a result, the cartridge 50 y is properly positioned in the apparatus main assembly 100 . Similarly, the cartridges 50 m, 50 c, and 50 k are properly positioned in the apparatus main assembly 100 . [0053] Further, as the cartridge 50 is made to descend toward the positioning portion 101 a by the movement of the door 12 , the projection 180 of the apparatus main assembly 100 comes into contact with the force receiving portion 71 c of the force receiving first member 71 , which is in the bottom portion of the cartridge 50 . That is, the force receiving member 71 receives force from the projection 180 , from the bottom side of the cartridge 50 . In comparison, when the door 12 is moved from the shut position to the open position (Y direction), the pressing member 61 moves in the direction indicated by an arrow mark J. As a result, the pressing member 61 separates from the top surface of the drum unit main frame 34 as shown in FIG. 5 . {Development Roller Separating Mechanism of Electrophotographic Image Forming Apparatus Main Assembly} [0054] Next, the operation of the force applying first portion 60 will be described. [0055] Referring to FIGS. 1 , 3 and 19 , in terms of the vertical direction of the apparatus main assembly 100 , the force applying member 60 is positioned so that after the proper positioning of the cartridge 50 , the force applying member 60 is above the cartridge 50 . In terms of the axial line of the photosensitive drum 30 , the force applying member 60 is positioned so that it is enabled to come into contact with the force receiving second member 70 which is at the corresponding lengthwise ends of the cartridge 50 . [0056] Driving force is transmitted from a motor 110 (mechanical power source) with which the apparatus main assembly 100 is provided, to a gear 112 through a gear 111 . As the driving force is transmitted to the gear 112 , the gear 112 rotates in the direction indicated by an arrow mark L, rotating thereby the cam portion 112 a, which is integral with the gear 112 , in the arrow L direction. The cam portion 112 a is in contact with the moving force receiving portion 60 b, with which the force applying member 60 is provided. Therefore, as the cam portion 112 a rotates, the moving force receiving member 60 is moved in the direction indicated by an arrow mark E or B. [0057] Referring to FIG. 19( a ), as the force applying member 60 moves in the direction indicated by the arrow mark E, a rib 60 y of the force applying member 60 separates from the force receiving second member 70 , as shown in FIG. 7 , allowing thereby the development roller 42 to come into contact with the photosensitive drum 30 . This position of the development unit 41 , which allows the development roller 42 to remain in contact with the photosensitive drum 30 , will be referred to as the contact position. [0058] Referring to FIG. 19( b ), as the force applying member 60 is moved in the direction indicated by the arrow mark B, the rib 60 y comes into contact with the force receiving second member 70 , subjecting the force receiving second member 70 to external force (second external force) through the rib 60 y. Therefore, the development unit 41 is rotated (rotationally moved) about the cylindrical portion 46 b (rotational axle), separating thereby the development roller 42 from the photosensitive drum 30 . This position of the development unit 41 , which keeps the development roller 42 separated from the photosensitive drum 30 , will be referred to as the separation position. [0059] Similarly, the force applying member 60 is positioned above the path of the cartridge 50 , through which the cartridge 50 is moved into the apparatus main assembly 100 by the cartridge tray 13 . The force receiving second member 70 is attached to the cartridge 50 in such a manner that until the cartridge 50 is moved into the apparatus main assembly 100 , the force receiving second member 70 remains in its standby position ( FIG. 5 ). Therefore, the force applying member 60 can be positioned significantly closer to the cartridge path, without allowing the force applying member 60 and cartridge 50 to interfere with each other during the mounting of the cartridge 50 , compared to the force applying member of an image forming apparatus in accordance with the prior art, making it possible to minimize wasted space, making it thereby possible to significantly reduce the cartridge 50 y in terms of its dimension in terms of its lengthwise direction (axial direction of photosensitive drum 30 ) as well as the vertical direction of the apparatus main assembly 100 . The detailed description of the force applying member 60 will be given later. [0000] {Description of Mounting of Process Cartridge into Electrophotographic Image Forming Apparatus Main Assembly, and Operation of Force Receiving Apparatus} [0060] Next, the operational sequence from the beginning of the mounting of the cartridge 50 into the apparatus main assembly 100 , to the separation of the development roller 42 from the photosensitive drum 30 , will be described. [0061] Referring to FIG. 4 , after the cartridge tray 13 is pulled out of the apparatus main assembly 100 to its outermost position, each cartridge 50 can be mounted into, or removed from, the cartridge tray 13 in the vertical direction, which is indicated by the arrow mark C. [0062] After the mounting of the cartridge(s) 50 into the cartridge tray 13 , the cartridge tray 13 is to be moved into the apparatus main assembly 100 in the direction indicated by the arrow Z 2 , through the opening 80 . That is, in this embodiment, each cartridge 50 is horizontally moved into the apparatus main assembly 100 , from the direction which is intersectional (roughly perpendicular) to the axial line of the photosensitive drum 30 . [0063] Referring to FIG. 3 , the cartridge 50 y is mounted in the downstream end of the cartridge tray 13 in terms of the direction in which the cartridge tray 13 is moved into the apparatus main assembly 100 . That is, the cartridge 50 y moves below the ribs 60 k 60 c, and 60 m of the force applying member 60 from upstream to downstream. [0064] If the apparatus main assembly 100 and cartridge 50 y are structured so that the force receiving second member 70 remains projecting when the cartridge 50 y is moved into the apparatus main assembly 100 , the pressing member 61 and force applying member 60 must be positioned significantly higher than they are positioned in this embodiment. In this embodiment, however, the apparatus main assembly 100 and cartridge 50 y are structured so that the force receiving second member 70 remains in the above described standby position when the cartridge 50 y is moved into the apparatus main assembly 100 . Therefore, the pressing member 61 and force applying member 60 can be positioned as closely as possible, without taking into consideration the distance by which the force receiving second member 70 projects beyond the external contour of the cartridge 50 y. In other words, the pressing member 61 and force applying member 60 can be positioned significantly closer to the path of the cartridge 50 y, making it possible to reduce the cartridge 50 y in dimension in terms of the direction parallel to the vertical direction of the apparatus main assembly 100 , compared to the counterparts of a process cartridge in accordance with the prior art. Further, referring to FIG. 20 , in terms of the direction parallel to the axial line of the drum 30 , the force receiving apparatus 90 , pressing member 61 , and force applying member 60 overlap, making it possible to reduce thereby the cartridge 50 y in dimension in terms of the lengthwise direction of the cartridge 50 y. [0065] Next, referring to FIG. 5 , the image forming apparatus in this embodiment is structured to ensure that when the cartridge tray 13 is moved into the apparatus main assembly 100 , there remain a gap f 1 between the force applying member 60 and force receiving second member 70 , and a gap f 2 between photosensitive drum 30 and transfer belt 19 . Therefore, the cartridge 50 and apparatus main assembly 100 do not interfere with each other when the cartridge 50 is moved into the apparatus main assembly 100 . [0066] After the cartridge tray 13 is pushed all the way into the apparatus main assembly 100 , the door 12 is to be moved into the shut position as shown in FIGS. 1 and 18( b ). As the door 12 is moved into the shut position, the tray supporting members 14 are moved toward the transfer belt 19 (direction indicated by arrow mark Y 2 ). Hereafter, the vertical component of this movement of the tray supporting members 14 in the direction indicated by the arrow mark Y 2 will be referred to as a distance f 2 . As the tray supporting members 14 are moved in the direction indicated by the arrow mark Y 2 , the cartridges 50 are moved toward the transfer belt 19 by the movement of the tray supporting members 14 , causing thereby the peripheral surface of the photosensitive drum 30 in each cartridge 50 to come into contact with the surface of the transfer belt 19 . By the time the peripheral surface of the photosensitive drum 30 comes into contact with the surface of the transfer belt 19 , the gap f 1 between the force receiving apparatus 90 and force applying member 60 widens to the sum of the gaps f 1 and f 2 , as shown in FIG. 5 . [0067] Further, as the door 12 is moved into the shut position, the pressing member 61 is moved by the movement of the door 12 , pressing thereby on the top surface of the drum unit main frame 34 . Therefore, the cartridge positioning portion 31 b of each cartridge 50 is placed in contact with the cartridge positioning portion 101 a of the apparatus main assembly 100 . Consequently, each cartridge 50 is properly positioned relative to the apparatus main assembly 100 , as shown in FIG. 7 . [0068] Further, a shaft 36 d, shown in FIG. 10 , with which the cover 36 of each cartridge 50 is provided, engages with the cartridge rotation stopping portion 13 a ( FIG. 17 ), with which the cartridge tray 13 is provided. Therefore, the cartridge 50 is prevented from moving further in the direction indicated by an arrow mark a in FIG. 1 , in the apparatus main assembly 100 . [0069] Next, referring to FIG. 6 , the home position of the force applying member 60 in this embodiment is made to be where the force applying member 60 keeps the development roller 42 separated from the photosensitive drum 30 . This is for the following reason. That is, while the image forming apparatus is not used for image formation after the mounting of the cartridges 50 , each cartridge 50 remains in the state shown in FIG. 8 . That is, the force applying member 60 has moved in the direction indicated by the arrow mark B, and the force receiving second member 70 has been moved by the rib 60 y as far as it can be moved. While the cartridge 50 is in this state, the photosensitive drum 30 and development roller 42 remain separated from each other. It is in this state, shown in FIG. 8 , in which the photosensitive drum 30 and development roller 42 remain separated from each other, that the cartridge 50 is removed from the apparatus main assembly 100 . Thus, when the cartridge 50 is mounted into the apparatus main assembly 100 next time, the force applying member 60 is in the position shown in FIG. 8 . Therefore, as the cartridge 50 is mounted, the force receiving second member 70 comes into contact with the rib 60 y, because the force receiving second member 70 is out of its standby position, as shown in FIG. 6 . Thus, the force receiving first portion 71 is provided with an elastic portion 71 b, which is formed as an integral part of the force receiving first portion 71 , as shown in FIG. 6 . Therefore, as the contact between the force receiving second member 70 and rib 60 y begins to interfere with the inward movement of the cartridge 50 , the elastic portion 71 b gives in (is compressed), preventing thereby the force receiving apparatus 90 from being damaged. [0070] As the force applying member 60 , which is in the state shown in FIG. 6 , is moved in the direction indicated by an arrow mark E as shown in FIG. 7 , the force receiving second member 70 projects outward farther from the cartridge 50 y, entering thereby the path of the rib 60 y. This position of the force receiving second member 70 , that is, the position in which the force receiving second member 70 is in the path of the rib 60 y, will be referred to as the outermost position (active position). That is, when the force receiving second member 70 is in its outermost position, the distance of the projection of the force receiving second member 70 is greater than that when the force receiving second member 70 is in the abovementioned standby position, which is obvious. In order for the force receiving second member 70 to engage with the force applying member 60 , the distance of the projection of the force receiving second member 70 at the outermost position must be greater than the sum of the gaps f 1 and f 2 . Further, the action of the force applying member 60 is triggered in a period between the completion of the mounting of the cartridges 50 into the apparatus main assembly 100 and the starting of an image forming operation. [0071] Next, referring to FIG. 8 , as the force applying member 60 is moved in the direction indicated by the arrow mark B, the lateral surface 70 c, which is the force receiving second portion of the force receiving second portion 70 , receives external force (second external force) through the rib 60 y 3 , since the force receiving second member 70 (lateral surface 70 c ) is in the path of the force applying member 60 . Therefore, the development unit 41 is rotationally moved about its rotational axis 46 b (shaft), causing thereby the development roller 42 to separate by a gap α from the photosensitive drum 30 . It is in its outermost position that the force receiving second member 70 receives the external force (second external force) from the force applying member 60 . Therefore, this structural arrangement is greater in the distance between the force applying member 60 and the rotational axis 46 b of the development unit 41 than a structural arrangement which moves the force applying member toward the process cartridge to separate the development roller from the photosensitive drum. Therefore, the employment of this structural arrangement makes it possible to reduce the amount of torque necessary to separate the development roller 42 from the photosensitive drum 30 . [0072] In this embodiment, the elastic portion 71 b is an integral part of the force receiving first member 71 . However, as long as it is enabled to absorb the force applied to the force receiving first member 70 by the abovementioned change in the position of the cartridge 50 , it may be formed as a part of another component, or as an independent component. For example, the force applied to the force receiving first member 71 by the change in the position of the cartridge 50 may be absorbed by placing an absorbing member independent from the force receiving second and first members 70 and 71 , between the force receiving second and first members 70 and 71 , or by forming the force receiving second member of an elastic material so that the above described force can be absorbed by the deformation of the force receiving second member 71 itself. [0073] Before the starting of an image forming operation, the force applying member 60 is moved in the direction indicated by the arrow mark E to place the development roller 42 in contact with the photosensitive drum 30 . As the force applying member 60 is moved in the abovementioned direction, the force receiving second member 70 stops receiving force from the rib 60 y, as shown in FIG. 7 . Therefore, the development roller 42 is placed in contact with the photosensitive drum 30 by the resiliency of the compression springs 95 provided between the development unit 41 and drum unit 31 , readying thereby the process cartridge 50 for image formation. It is before the development roller 42 comes into contact with the photosensitive drum 30 that the photosensitive drum 30 begins to be rotated, and the development roller 42 begins to be rotated, by the driving force which the cartridge 50 receives from the apparatus main assembly 100 through the coupling portion 67 . This is for the following reason. That is, referring to FIG. 10( a ), the coupling portion 67 is made coaxial with the cylindrical portion 46 b so that even when the development unit 41 moves about the cylindrical portion 46 b, the coupling portion 67 does not change in position. That is, in this embodiment, it is before the development roller 42 is placed in contact with the photosensitive drum 30 that the development roller 42 and photosensitive drum 30 begin to be rotated. This arrangement makes it possible to minimize the difference in peripheral velocity between the photosensitive drum 30 and development roller 42 when the development roller 42 comes into contact with the photosensitive drum 30 . Therefore, it can minimize the amount of the wear that occurs to the photosensitive drum 30 and development roller 42 when the two come into contact with each other. After the completion of the image forming operation, the development roller 42 is separated from the photosensitive drum 30 by moving the force applying member 60 in the direction indicated by the arrow mark B as described above. It is after the separation of the development roller 42 from the photosensitive drum 30 that the development roller 42 and photosensitive drum 30 are stopped. Thus, this arrangement minimizes the difference in the peripheral velocity between the development roller 42 and photosensitive drum 30 , which occurs when the two become separated. Therefore, it minimizes the amount by which the development roller 42 and photosensitive drum 30 wear when they are separated from each other. Consequently, this arrangement improves an image forming apparatus in image quality. [0074] Next, the operation for removing the cartridge 50 from the apparatus main assembly 100 will be described. [0075] First, the door 12 is to be moved from its shut position to the open position. As the door 12 is moved, the tray supporting members 14 are raised in the direction to separate from the transfer belt 19 as shown in FIGS. 3 and 4 . Therefore, the cartridges 50 are moved upward, causing the photosensitive drum 30 in each cartridge 50 to separate from the transfer belt 19 . Further, the pressing member 61 is rotated in the direction indicated by the arrow mark J in FIG. 5 , being separated from the drum unit 31 , as described above. Thus, the force receiving first member 71 separates from the projection 180 , being thereby deprived of the force to keep the force receiving second member 70 projecting beyond the external contour of the development unit 41 . [0076] As for the force receiving second member 70 , its slant surface 70 y 2 comes into contact with the slant surface 60 y 2 of the force applying 60 , as shown in FIG. 21 . Thus, the force receiving second member 70 is rotationally moved about its rotational axis 70 a, back into its standby position (inaction position), by the component of the force to which the slant surface 70 y 2 is subjected as the cartridge 50 (cartridge tray 13 ) is pulled out. Incidentally, a spring may be employed, as in another embodiment of the present invention, as the means for generating the force for returning the force receiving second member into its standby position. That is, the first embodiment, in which the abovementioned spring is not employed, was presented as the embodiment which is smallest in the components count. [0077] As described above, in this embodiment, the apparatus main assembly 100 and cartridge 50 are structured so that as the door 12 is moved into its shut position after the cartridge 50 is mounted into the apparatus main assembly 100 , the force receiving second member 70 for moving the development unit 41 projects beyond the outward surface of the development unit 41 . Therefore, the cartridge 50 in this embodiment is significantly smaller in height than a cartridge ( 50 ) in accordance with the prior art. Further, the force receiving second member 70 remains in its standby position while the cartridge 50 is mounted. Therefore, the space necessary, in the apparatus main assembly 100 in this embodiment, for the movement of the cartridge(s) 50 does not need to be as large as that in the main assembly of an image forming apparatus in accordance with the prior art. That is, the present invention makes it possible to reduce the opening 80 in size, and also, makes it possible to place the force applying member 60 significantly closer to the path of the cartridge 50 than the prior art, making it thereby possible to reduce the apparatus main assembly 100 in vertical dimension. Further, the force receiving apparatus 90 , pressing member 61 , and force applying member 60 are positioned so that they overlap in terms of the direction parallel to the axial line of the drum, as shown in FIG. 20 , making it possible to reduce the cartridge in its lengthwise dimension. [0078] Further, when the cartridge 50 is handled by a user, or is transported alone, the force receiving second member 70 remains in its standby position, being therefore unlikely to be damaged. [0079] In this embodiment, the apparatus main assembly 100 is structured so that its projection 180 is below the path of the cartridge 50 . However, as long as the projection 180 comes into contact with the force receiving first member 71 while the cartridge 50 is mounted into the apparatus main assembly 100 , it does not matter where the projection 180 is positioned. Moreover, the shape of the projection 180 is optional, as long as the projection 180 is enabled to move the force receiving portion 71 c by coming into contact with the force receiving portion 71 c. In other words, the force receiving portion 71 c may be a stationary projection which projects from the cover 46 . However, if the force receiving portion 71 c is made stationary, the force receiving portion 71 c must be adjusted in height to prevent the force receiving portion 71 c from coming into contact with the apparatus main assembly 100 while the cartridge 50 y is mounted into the apparatus main assembly 100 . Embodiment 2 [0080] Next, referring to FIGS. 12 and 13 , another preferred embodiment of the present invention will be described. In this embodiment, the cartridge 50 is provided with a first lever 471 , a second lever 470 , and a gear 472 . The first lever 471 has a force receiving first portion 471 c. The second lever 470 has a force receiving second portion 470 c, and meshes with the gear 472 . This structural arrangement can move the second lever by a greater distance than the distance by which the first lever is moved. [0081] The gear 472 is a step gear made up of a portion (first portion) which engages with the first lever 471 and is n 1 in tooth count, and a portion (second portion) which engages with the second lever 470 and is n 2 in tooth count. Thus, it is possible to amplify the distance by which the first level 471 is moved by making the tooth count n 2 of the second portion of the gear 472 greater than the tooth count n 1 of the first portion of the gear 472 (n 2 >n 1 ). To concretely described the operation of the force receiving apparatus in this embodiment, referring to FIG. 12( a ), while the cartridge 50 is inserted into the apparatus main assembly 100 , the second lever 470 remains within the cartridge 50 . Then, when the cartridge 50 is properly positioned relative to the apparatus main assembly 100 by the cartridge positioning portion 101 a, the force receiving first portion 471 c begins to receive external force (first external force) from the projection 180 , being thereby moved upward as indicated by an arrow mark F 2 . As the force receiving first portion 471 c moves upward as indicated by the arrow mark F 2 , the gear 472 is rotated, and this rotation of the gear 472 causes the second lever 470 to move upward. Thus, immediately after the cartridge 50 is properly positioned by the cartridge positioning portion 101 a, the second lever 470 is in its outermost position as shown in FIG. 12( b ). When the second lever 470 is in its outermost position, the force receiving portion 470 c of the lever 470 receives the external force (second external force) from the rib 60 y 3 in the same manner as the force receiving second portion 70 c of the force receiving second member 70 receives external force from the rib 60 y 3 in the first embodiment. [0082] Further, in this structural arrangement, a coil spring 473 is provided to ensure that the second lever 470 always returns to its standby position. The reason therefor is as follows: It is assumed that from the standpoint of apparatus design, it is difficult to ensure that the component of the force which the slant surface 60 y 1 receives is large enough to return the force receiving portion 470 c to its original position (for example, if the amount of the force necessary to pull cartridges (cartridge tray) increases). In other words, the provision of the coil spring 473 is not mandatory, as it is not in the first embodiment. [0083] This embodiment, however, will be described with reference to a case where the coil spring 473 is provided. In this case, unless the resiliency of the coil spring 473 is smaller than the resilience of the elastic portion 471 b which is an integral part of the lever 471 , the force receiving first member 470 is not allowed to move. Therefore, all that is necessary is to set the relationship between a force F 1 which is generated by the coil spring 473 , and a force F 2 which is generated by the elastic member 471 b, to be F 1 <F 2 . [0084] In this embodiment, the cartridge 450 is designed to be assembled in the following manner: First, the gear 472 is rotatably supported by the cover 446 which is firmly attached to the bearing unit 445 , and then, the second lever 470 and first lever 471 are attached so that the two levers mesh with the corresponding portions of the gear 472 . The shape of the apparatus main assembly in this embodiment is the same as that of the apparatus main assembly in the first embodiment. Therefore, the force receiving portion which is necessary to place the development roller in contact with the photosensitive drum, or separating the development roller from the photosensitive drum, is the tip 470 c of the second lever 470 . Otherwise, this embodiment is the same as the first embodiment. [0085] As described above, the force receiving apparatus in this embodiment is the same in effectiveness as that in the first embodiment. In this embodiment, however, the distance by which the second lever is moved can be easily changed by changing the gear ratio between the first and second portions of the gear 472 . [0086] Also in this embodiment, when the cartridge tray is pulled out, the force receiving member 470 comes into contact with the slant surface 60 y 2 . Then, as the cartridge tray is pulled out further, the force receiving second member 470 is pushed back into the development unit, and stored therein, by being moved in the direction indicated by an arrow mark F 2 by the slanted surface 60 y 2 . Therefore, the provision of the return spring 473 is not mandatory. Embodiment 3 [0087] Next, referring to FIGS. 14 and 15 , the third embodiment of the present invention will be described with reference to a case where the force receiving first member belongs to a drum unit 531 . First, the method for assembling the cartridge in this embodiment will be described. The cartridge in this embodiment is designed so that a force receiving first member 571 belongs to a drum unit 531 . A force receiving second member 570 and a connective rod 574 are attached to a cover 546 . Then, the cover 536 is joined with a bearing member 545 . Lastly, the development unit 541 and drum unit 531 are connected by the cover 536 to complete the cartridge 550 . [0088] To describe in more detail the cartridge 550 in this embodiment with reference to FIGS. 14 and 15 , first, referring to FIG. 14 , a projection 5180 of the apparatus main assembly is located so that it opposes the drum unit. Thus, the force receiving first member 571 is placed in the drum unit 531 . [0089] The drum unit is provided with the force receiving first member 571 , which has a force receiving first portion 571 c and is movable. Further, the drum unit is provided with a rod 571 and a connective rod 574 . The connective rod 574 is rotationally movable about the rotational axis 574 a while remaining in contact with the rod 571 . The development unit is provided with a force receiving second member 570 , which has an elongated hole 570 b and is rotationally movable about a rotational axis 570 a. Further, the opposite lengthwise end of the connective rod 574 from the rod 571 is provided with a projection (connective pin) which fits in the elongated hole of the force receiving second member 570 . [0090] When the cartridge 550 is properly positioned relative to the apparatus main assembly 101 by the cartridge positioning portion 101 a, the force receiving first portion 571 c begins to receive external force (first external force) from the projection 5180 . Therefore, the force receiving first member 571 begins to be moved in the direction indicated by an arrow mark I as shown in FIG. 14( b ), causing the connective rod 574 to rotationally move in the direction (clockwise direction) indicated by an arrow mark m. Thus, the force receiving second member 570 is rotationally moved about the rotational axis 570 a in the direction to move the opposite end portion of the 570 from the elongated hole 570 b, arcuately upward, as indicated by an arrow mark n. Since the curvature of the elongated hole 570 b is such that while the development roller is not in contact with the photosensitive drum, the center of the curvature of the elongated hole 570 b coincides with the rotational axis of the development unit 541 . Therefore, while the development unit 541 is separated from the drum unit 531 , the connective rod 574 is subjected to no load. Also in this embodiment, a return spring ( 573 ) is provided. However, the return spring 573 may be eliminated by a design change. [0091] Also in this embodiment, the distance by which the force receiving second member is moved can be made greater than the distance by which the force receiving first member is moved, by properly selecting the leverage ratio of the connective rod. [0092] Further, in this embodiment, when the cartridge tray is pulled out, the force receiving member 570 comes into contact with the slant surface 60 y 2 as does the force receiving first member 70 in the first embodiment. Then, as the cartridge tray is pulled out further, the force receiving second member 570 is pushed back into the development unit 541 to be stored therein, by being moved in the direction opposite from the direction indicated by the arrow mark n. Therefore, the provision of the return spring 573 is not mandatory. [0093] According to the present invention, it is possible to reduce in size a process cartridge, the electrophotographic photosensitive drum and development roller of which can be placed in contact with, or separated from, each other. It is also possible to reduce in size an electrophotographic image forming apparatus which employs the abovementioned process cartridge. Further, it is possible to structure an electrophotographic image forming apparatus so that its force receiving apparatus for separating the development roller from the electrophotographic photosensitive drum is unlikely to be damaged while the abovementioned process is handled by a user, or is transported alone. [0094] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims. [0095] This application claims priority from Japanese Patent Applications Nos. 172742/2007 and 162311/2008 filed Jun. 29, 2007 and Jun. 20, 2008, respectively, which are hereby incorporated by reference.

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes an electrophotographic photosensitive drum; developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum; drum frame supporting the electrophotographic photosensitive drum; a developing frame supporting the developing roller, the developing frame is movable relative to the drum frame and is capable of taking a contacting position in which the developing roller is in contact with the electrophotographic photosensitive drum; and a force receiving device including a first force receiving portion for receiving a first external force and a second force receiving portion for receiving a second external force, wherein the second force receiving portion is movable relative to the developing frame, wherein the second force receiving portion is placed in a stand-by position retracted from an operating position by the first force receiving portion receiving the first external force, and is movable from the stand-by position to the operating position for moving the developing frame from the contacting position to the spacing position, wherein a distance through which the second force receiving portion moves from the stand-by position to the operating position is larger than a distance through which the first force receiving portion is moved by the first external force.

FIELD OF THE INVENTION [0001] This invention relates to electronic displays and an improved switching control circuit based on diodes for the control of the circuit. BACKGROUND AND PROBLEM TO BE SOLVED [0002] In an electronic display, a material, called the display medium, changes its optical state, e.g. reflectivity, transmission or light emission, in response to an electrical signal such as a voltage or an injected current. Particularly widely used are liquid crystal displays (LCDs), which change either the polarization of light or the reflectivity for light under the influence of voltage. Typically the display architecture comprises a transparent front substrate coated with a transparent conductive electrode, e.g. Indium Tin Oxide (ITO), which may be patterned or unpatterned (the front plane), a back plane comprising electrodes which may optionally be transparent and an optional substrate which may also optionally be transparent, and the display medium place between the front and back plane. The control of the optical state of the display results from the application of a voltage between the front and back plane electrodes which creates an electric field across the display medium or injects a current into the medium. The display may be divided into segments or, for more complicated information, into so-called pixels organised into a matrix of rows and columns. [0003] Some display media display image retention without being actively addressed, i.e. once an image is written to a display based on such a medium, no further power is needed to maintain the image, at least for a significant amount of time. Such displays are commonly called bi-stable, even though many such displays are not strictly speaking truly bi-stable (having two stable states of equal energy), and this terminology will be applied herein as well. [0004] Two types of bi-stable displays that have generated significant interest for “electronic paper” applications are electrochromic displays, such as reported and provided by NTera Inc. (www.ntera.com), and electrophoretic displays such as are reported and provided by E Ink Inc. (www.eink.com) and Sipix (www.sipix.com). These displays show optical properties that in many ways are similar to ink on paper. However, these displays generally require an active matrix structure (an active electronic circuit controlling the electronic and optical state for each pixel) in order to display detailed information, as they are not addressable by passive matrix techniques and/or the response times are too slow for passive matrix line by line addressing. [0005] Active matrix circuits may be constructed on the basis of thin film transistors (TFTs), which are three terminal devices, or two terminal devices such as rectifying diodes and MIM diodes. TFTs have become the standard technique for LCDs. In a TFT display, patterning is all done on the back plane of the display, with row and column lines connected to gate and source electrodes; the front plane electrode is typically unpatterned throughout the active area of the display. This has the advantage of reducing the requirements for alignment of front and back planes during assembly, which is especially important for displays which are made using printing technology and/or flexible substrates, e.g. using organic semiconductors for the TFTs (see, for example, www.plasticlogic.com). On the other hand, TFTs require very fine patterning steps and excellent semiconductor characteristics, especially charge carrier mobility, to perform adequately, and both issues become difficult when using printing technology and organic semiconductors. [0006] A number of diode-based active matrix back plane structures have been disclosed in the past and some have also been used commercially. Two structures are the diode ring and the back-to-back diode configuration, as seen in FIG. 1 . [0007] The display medium is in series with the diode circuit; the diode circuit and the display medium are placed between the row and column electrodes. [0008] Another diode circuit design is called the two-diode switch, and the circuit is illustrated in FIG. 2 . This circuit configuration requires both a patterned front plane electrode structure and two select lines for each row of pixels. Patent application WO 2004/066410 discloses diode based circuits for active matrix back planes using single diode and back-to-back configurations, where the diodes are thin film diodes made using organic semiconductors ( FIG. 3 ). Two potential advantages of organic diodes over organic TFTs are less stringent requirements on charge carrier mobility and less stringent requirements on resolution due to the vertical instead of horizontal structure of the charge conducting layer. These two advantages can be especially significant for cost-efficient, high-throughput printing based manufacturing of active matrix back planes, as the resolution achievable with standard printing methods is limited. As in FIGS. 1 and 2 , a patterned front plane electrode is used. [0009] Metal-insulator-metal diode (M-I-M) diodes differ from rectifying diodes in that the current-voltage curves are symmetrical. MIM diodes have also been used to form active matrix back planes for displays; and example structure is shown in FIG. 4 . Note that also here the display medium (here a liquid crystal) is in series with the diode element in between row and column electrodes, i.e. the front plane electrode must be structured. [0010] Active matrix back planes based on solution processible MIM diodes have been disclosed in patent application disclosure WO 2004/051750 and in U.S. Pat. No. 6,380,922. In the former no description of a circuit or reduction to practice is given. In the latter, printed MIM diodes based on inorganic metal oxides are claimed for use in active matrix displays, preferably electrophoretic displays. An unpatterned front plane electrode is used in the proposed circuit, which can drive a single pixel, but no disclosure is made how an entire matrix of rows and columns could effectively be driven. [0011] U.S. Pat. No. 6,980,196 discloses an electronic display where the display medium is particle based, e.g. electrophoretic, and controlled by an active matrix which may comprise printable nonlinear diode elements, the intention being the fabrication of a printable active matrix display. The display medium is placed in series with the nonlinear device between row and column electrodes, i.e. the disclosure requires patterned front plane electrodes. However, as mentioned above, having structured elements on both the front and back plane create additional alignment difficulty, especially if printing and lamination processes are used for display fabrication and assembly. Furthermore, some display media, e.g. electrophoretic and polymer-dispersed liquid crystal media, are frequently commercially available primarily as front plane laminates with the active display medium already laminated onto an unpatterned front plane. SUMMARY OF THE INVENTION [0012] Therefore an object of the invention is to disclose a diode based back plane circuit that can drive a display medium, especially a bistable display medium, effectively in a matrix configuration such that row and column address lines are both on the back plane and the front plane is essentially unpatterned in the active display area. Furthermore, the driving circuit matrix should be able to drive a full matrix display with good contrast between optical states, and with the highest possible power efficiency. [0013] The invention discloses diode based backplane circuits that are able to drive a display medium, especially a bi-stable display medium, in an active matrix mode with a minimum of additional voltage and leakage current, without the need for a patterned front plane, and with optical performance comparable to directly driven displays and TFT active matrix displays [0014] In one embodiment, the diode active matrix back plane disclosed herein comprises a matrix of row and column address lines on the back plane, with two rectifying diodes in series between the row and column lines, plus a load impedance in series with the diodes and disposed between the second diode and the row line. The display medium is located between the backplane and an unstructured front plane electrode structure, and the back pixel electrode of the display medium is connected to the diode circuit between the two diodes. The back plane architecture and the addressing scheme used are suitable for bi-stable display media possessing a short circuit memory (i.e. able to maintain an image even when the front and back electrodes are connected and at the same potential) without a patterned front plane. All the pixel capacitors share a common front electrode [0015] In another embodiment of the invention, the display pixel electrode is still connected to the circuit between the two diodes, but the load resistor is made unnecessary, by choosing a diode-diode configuration in which the diodes have different forward resistances at chosen current values. [0016] In a further embodiment of the invention, the pixel electrode is connected to the circuit between a source lead at either a driving voltage or ground and two diodes which are connected to the row and column lines. Depending on the source voltage and the direction of the diodes, this circuit functions like an AND or OR gate to drive the pixels. This circuit is also able to drive a bistable display with an unpatterned front plane. [0017] According to a first aspect of the present invention there is provided a display comprising a plurality of row electrodes; a plurality of column electrodes; a plurality of pixels, each pixel of said plurality of pixels being assigned to a crossing of one row electrode and one column electrode; a plurality of pixel electrodes each assigned to one pixel; a plurality of pixel driving circuits for controlling the state of said plurality of pixels; and a display medium; wherein each of the driving circuits comprises a load impedance; a first diode connected between one row electrode and said pixel electrode; and a second diode connected between one column electrode and said pixel electrode, and said at least one row electrode, said at least one column electrode and said pixel electrode are on the same side of the display medium. [0028] According to a second aspect of the present invention there is provided a circuit for driving a display, the display comprising a plurality of row electrodes; a plurality of column electrodes; a plurality of pixels, each pixel of said plurality of pixels being assigned to a crossing of one row electrode and one column electrode; a plurality of pixel electrodes each assigned to one pixel; wherein said driving circuit comprises a load impedance; a first diode connected between one row electrode and said pixel electrode; and a second diode connected between one column electrode and said pixel electrode. DESCRIPTION OF THE DRAWINGS [0036] FIGS. 1-4 show examples of the known state of the art for diode based display driving circuits, which require a patterned front plane; [0037] FIG. 5 shows the unit circuit for one pixel of one embodiment of the invention; [0038] FIG. 6 demonstrates graphically the relationships between resistances under different driving conditions in one embodiment of the invention; [0039] FIG. 7 shows the unit circuit for one pixel of another embodiment of the invention; [0040] FIG. 8 shows the unit circuit for one pixel of further embodiment of the invention; [0041] FIG. 9 shows an example of a backplane circuit for one embodiment of the invention; [0042] FIG. 10 shows an embodiment of the invention in which the driving circuit is disposed laterally to the display pixel electrode; [0043] FIG. 11 show a first embodiment of the invention in which the driving circuit is disposed vertically to the display pixel electrode; [0044] FIG. 12 show a second embodiment of the invention in which the driving circuit is disposed vertically to the display pixel electrode; and [0045] FIG. 13 show an example of a device in which the invention can be applied. DETAILED DESCRIPTION OF THE INVENTION [0046] Four embodiments of the diode based matrix driving circuit are disclosed herein. In the description of these embodiments the following terminology will be used: Row==Row Col==Column Pixel==Pixel [0047] R==loading resistor RRR==diode reverse resistance C==Pixel capacitance against front plane Vs==source voltage Vd==diode threshold voltage [0048] In one embodiment, a unit cell of which is shown in FIG. 5 , the unit cell 10 (pixel) of the diode active matrix back plane disclosed herein comprises a connection to row address lines 11 and column address lines 12 on the back plane, with two rectifying diodes 13 and 14 in series between the row and column lines, plus a load impedance 15 in series with the diodes and disposed between the second diode and the row line. The display medium is located between the backplane and an unstructured front plane electrode structure, and the pixel back electrode 16 of the display medium is connected to the diode circuit between the two diodes. [0049] The relationship of impedances in a single pixel element is sketched in FIG. 6 . In forward bias the resistance Rl of the load resistor 15 is dominant wherein the forward bias resistance Rf of the diodes 13 , 14 is negligible and the voltage drop is essentially over this load resistor 15 . In reverse bias the resistances Rr of the diodes 13 , 14 are dominant wherein the resistance Rl of the load resistor 15 is negligible. [0050] The following truth table describes the state of the pixel back electrode as a function of the voltages on the row 11 and column address line 12 to which it is connected via the circuit according to the invention. If the voltage in the row address line 11 (row voltage) is at 0 that row is selected and the state of the pixel can be changed. A voltage of 0 at the column address line 12 (column voltage) will cause a charged pixel to discharge at a time defined by the load resistance and the pixel capacitance, while an uncharged pixel remains uncharged. A column voltage of Vs will not change the state of a pixel electrode at Vs-Vd but will charge an uncharged pixel to Vs. If the row voltage is Vs (unselect), then a column voltage of 0 will in principle cause the pixel to charge or discharge to Vs/2 but due to the extremely high reverse bias resistance of the diodes this process will be too slow to observe and the pixel will remain in the same state. If the row and column are both at Vs, then the pixel electrode will be at Vs-Vd. [0000] Pixel Row Column RC −> 0, 0 0 0 Vs − Vd 0 Vs RRRC −> Vs/2 Vs 0 Vs − Vd Vs Vs [0051] Based on the above truth table, it can be seen that for the example of a bistable display medium with short circuit memory (i.e. a medium for which the optical state does not change if the front and back electrodes are at the same potential) with the front plane at Vs-Vd, the situation in which both row voltage and column voltage are at 0 will force the pixel to a state with a potential of −(Vs-Vd), while for the other combinations the state of the pixel will be unchanged. [0052] In addition to enabling the control of the pixel state, the loading impedance also enables to lower the current consumption of the diode active matrix backplane. This is due to the current limiting nature of the loading impedance. There are a number of preferential embodiments of this embodiment of the invention disclosed herein. It is advantageous if the load impedance is at least 100 kOhm and especially preferred if the load impedance is over 1 MOhm. The value of the loading impedance must be selected such that Rf<Rl<Rr, where Rf is the forward impedance of the diodes, Rl the load impedance of the pixel and Rr is the reverse impedance of the diodes. [0053] The reverse bias current of the diodes is advantageously less than 1 μA per pixel, preferentially less than 1 nA. The rectification ratio of the diodes is advantageously larger than 100, and preferentially larger than 1000. [0054] In another embodiment of the invention, the load resistor is replaced by a diode-diode configuration in which the diodes have different forward resistances at chosen current values. This can be taken into account with the driving wave forms by setting the pixel capacitors to the same voltage as the front plane. [0055] There are other possible alternatives to realise a pixel driving scheme without structured front plane. In a further embodiment of the invention the driving scheme is realised with diode logic gated with either AND or OR structure. [0056] A unit circuit for the AND configuration is shown in FIG. 7 and the truth table is analysed similarly to the embodiment above. The unit cell 20 of the diode active matrix back plane comprises a connection to row and column address lines 21 and 22 and a source voltage Vs 23 on the back plane. Between the source and the row and column electrodes are disposed diodes 24 and 25 and load resistor 26 . The back pixel electrode 27 is disposed between the load resistor and the diodes. In the AND configuration the pixel electrode is discharged to 0 unless both the row and column are at Vs. Truth Table for AND [0057] [0000] Pixel Row Column RC −> 0 0 0 RC −> 0 0 Vs RC −> 0 Vs 0 Vs − Vd Vs Vs [0058] A unit circuit for the OR configuration is shown in FIG. 8 and the truth table is analysed similarly to the embodiment above. The unit cell 30 of the diode active matrix back plane comprises a connection to row and column address lines 31 and 32 and to a ground connection 33 on the back plane. Between the ground and the row and column electrodes are disposed diodes 24 and 25 and load resistor 26 . The back pixel electrode 37 is disposed between the load resistor and the diodes. In the OR configuration the pixel electrode is at Vs if either the row is column are at Vs and 0 if both are at 0. Truth Table for OR [0059] [0000] Pixel Row Column RC −> 0 0 0 Vs − Vd 0 Vs Vs − Vd Vs 0 Vs − Vd Vs Vs [0060] A matrix backplane 40 can be constructed by connecting row electrodes and column electrodes together as described in FIG. 9 for the first embodiment described. Row electrodes 41 - 43 and column electrodes 44 - 46 are disposed on the back plane of a display, with unit circuits 47 disposed between the row and column electrodes as disclosed above. [0061] The embodiments described above can drive a display under assumption that the display medium is bistable and has a short circuit memory, i.e. the medium does not change its optical state if there is no potential difference between the front and back plane electrodes. [0062] A display driving scheme according to the invention is based on the fact that if there is no potential difference between the pixel electrode and the front plane the pixel remains optically unchanged. This enables possibility to construct a circuit and driving scheme in such a way that once a row is unselected all pixel electrodes in that row are in the same potential with front plane. [0063] The following example illustrates a driving scheme for a bistable display according to FIG. 9 . [0064] The front plane potential is initially set to Vs-Vd. Setting a row to Vs results in a situation where all the pixels at that row will be set to Vs-Vd. As this is the same potential as the front plane the optical state of the pixel will remain unchanged. However if the row is selected by setting it to 0, which is a different potential compared to the front plane, it is possible to determine the pixel voltage by controlling the state of the column electrodes. If a column is set to Vs the pixel is unchanged, since the voltage in pixel electrode is Vs-Vd. If the column voltage is set to 0 the pixel voltage decays to 0 at a fairly rapid rate determined by the load resistance and generates a potential difference between the pixel electrode and front plane. Therefore the optical state of the pixel is changed as there is a potential difference between front plane and pixel electrode. [0065] In a preferred embodiment of the driving scheme useful for display media that are sensitive to DC-imbalance, the pixel driving is reset at the end of each row driving sequence. This is done by setting all pixel electrodes to the same potential as front plane. This is done by setting the front plane to Vs-Vd, the row to be reset to Vs and all column electrodes to Vs. [0066] In another preferred embodiment of the invention, the diodes comprise organic semiconductor material, especially solution processed organic semiconductor material. It is especially preferred if the diodes and if possible also the resistors are deposited by printing techniques, especially for organic semiconductor diodes. In another preferred embodiment the display medium is a bi-stable display medium, especially a reflective display medium, and in particular an electrophoretic display medium. It is especially preferred if the back plane, the front plane and the display medium are all flexible. Geometries [0067] In another embodiment of the invention a display is manufactured by preparing a back plane structure according to the circuits described above, with the same advantageous embodiments as described for the circuit and the display, then laminating a display medium previously laminated onto an unpatterned front plane electrode structure to the back plane to make an active matrix display. [0068] The circuit components may be situated next to the pixel electrode, with lateral contacts from the appropriate terminals of the diode to the pixel, as shown in FIG. 10 for the example of the first embodiment of the invention disclosed herein. An active matrix backplane 50 comprises row lines 51 - 53 , insulators 54 disposed on top of the row lines, column lines 55 - 57 crossing the row lines at the points where the insulators are deposited, and between the row and column lines diodes 58 , resistors 59 and pixel electrodes 60 laterally oriented and connected in such as way as to form unit cells as shown in FIG. 5 . [0069] For display media that are opaque, such as electrophoretic or rotating ball displays, it may be preferable to dispose the diode matrix underneath rather than next to the pixel electrode, a geometry which may be referred to as a “vertical pixel architecture”. [0070] WO 2004/070466 discloses a version of a vertical pixel architecture, useful for e.g. electrophoretic displays, on the basis of thin film transistors (TFTs), whereby the pixel electrode is disposed above the TFT matrix, separated by a dielectric material layer, and connected to the drain electrode by means of a via hole in the dielectric. U.S. Pat. No. 6,232,950 discloses a display architecture in which conductors are disposed onto a substrate, covered by a dielectric layer with via holes, and a pixel electrode is deposited onto the dielectric layer in such a way that the via holes are filled and electrical connection is made to the lead lines. [0071] A matrix based on thin film diodes and resistors, i.e. a structure comprising not only conductive patterns but also active components comprising semiconductors may also be disposed underneath the pixel electrode. FIG. 11 demonstrates one embodiment of such a display architecture according to the invention in the example of a single pixel 100 . Upon a substrate 101 are disposed a row line 102 , resistor 103 , diodes 104 and 105 , column line 110 and a dielectric layer comprising vias 109 . Upon this is disposed a pixel electrode 106 in such a way that the vias are filled and make contact between the pixel electrode and the driving circuit. The display electrode 106 is adjacent to the display medium 107 and the front plane electrode 108 . [0072] U.S. Pat. No. 6,445,374 discloses a display architecture in which conductors are disposed onto one side of a substrate comprising via holes at appropriate locations, the pixel electrodes are disposed onto the other side of the substrate and contact is made through filling of the via holes. [0073] In another embodiment of a vertical pixel architecture for circuits according to the invention, as sketched in FIG. 12 in the example of a single pixel 200 . Upon a substrate 201 comprising vias 209 are disposed on one side of the substrate a row line 202 , resistor 203 , diodes 204 and 205 and column line 210 . On the other side of the substrate 201 is disposed a pixel electrode 206 in such a way that the vias are filled and make contact between the pixel electrode and the driving circuit. The display electrode 206 is adjacent to the display medium 207 and the front plane electrode 208 . [0074] Similar vertical pixel architectures can be based on the other embodiments of the invention disclosed herein, according to the same principles as outlined in FIGS. 11 and 12 . [0075] FIG. 13 illustrates an example of a device 130 in which the driving system of the present invention can be implemented. The device 130 is, for example, an electronic price label, an information display, etc. The device 130 comprises a controller 131 for controlling the operation of the device 130 . The device 130 also comprises a memory 132 for storing information, software programs, parameters etc. The device may also have an input element 133 for inputting information such as price data, updated versions of software, new parameter values, etc. The device 130 may also comprise a keyboard 134 which the user can use to input data to the device 130 . The display driver 136 of the device 130 forms the row and column voltages for each row address lines and column address lines so that pixels of the display 137 are in a desired state to show information to be displayed. Also when the information to be displayed changes the display driver 136 makes the necessary adjustments to the row and column voltages. It is noted here that the row and column voltages are dependent on inter alia which of the embodiments disclosed herein is used. [0076] Information to be shown may be stored into the memory 132 . For bi-stable media, especially those which are sensitive to DC-imbalance and/or such media in displays that should display grey scales, the memory may contain also a look-up table in which the current state of each pixel is stored, since the driving waveform needed to switch the pixel to another state or maintain the current state depends on the current state of the pixel. The controller 130 reads the information from the memory 132 e.g. pixel by pixel and sends the information to the display driver 136 . The display driver 136 sets correct row and column voltages on the row and column address lines as was disclosed above in connection with FIG. 9 . Changes to row and column voltages are only necessary when one or more pixel states need to be changed thus power consumption can be kept very low. [0077] The driving circuit of the invention is also applicable to colour display. For colour displays each pixel element is divided into a plurality of sub-pixels, e.g. red, green and blue or cyan, yellow and magenta, each created for example by use of an appropriate colour filter with a black and white display medium or use of patterned display media with different colours. In some cases a white sub-pixel may also be added to a reflective display to increase the display brightness. Each sub-pixel will then be controlled by its own pixel control circuit as disclosed herein.

An active-matrix electronic display including a switching circuit for each pixel to control the optical state of the display. The switching circuit includes at least one diode and at least one load impedance for each circuit. The front plane electrode of the display may be unpatterned over a significant portion of the display. The display architecture is especially useful for bi-stable display media that require active matrix addressing, for example electrophoretic displays, and for applications using diodes based on organic semiconductors and/or printed diodes.

The present invention relates to a unidirectional glass fabric produced with continuous yarn which is twisted, plied or has zero twisting turns, with different gram weights and interlaced with thin glass yarns as a stabilizing binding, as well as to use thereof in the manufacture of printed circuits. BACKGROUND OF THE INVENTION Glass fabric is used nowadays with success in a wide range of applications. Among the main ones, mention may be made of those applications involving advanced structural composites for the aeronautical and naval industries and dielectric composites for the electrical and electronics industry. In particular, the Applicant's interest is directed towards the manufacture of glass fabrics for use in the electrical and electronics industry, preferably the construction of laminates for printed circuits and the manufacture of fabrics and gauzes used as a reinforcement in numerous industrial applications. The miniaturization of electronic devices is giving rise to various assembly problems, including the concentration of tracks on printed circuits and hence the need for making the tracks thinner. This innovative process has not radically affected the criteria for laminate production, but is requiring the use of glass fabrics which are much more refined than those currently used. In particular, the weaving industry is having to find solutions for the problems associated with the surface of the fabrics, which need to be increasingly flat and smooth and as far as possible devoid of loose pile and textile defects in general, and with dimensional stability, which must be kept as low as possible. It is obvious that conventional glass fabric, which constitutes the structural support of the laminate, based on a cloth weave, is no longer suited for tolerating a reduction in these parameters. Consequently it is necessary to provide a glass fabric with an increasingly higher performance compared to the fabrics currently used. On account of the increasingly stringent specifications for printed circuits, the person skilled in the art is now having to regard as critical certain aspects of the laminates, such as the surface waviness, dimensional stability, warping, perforability, thickness, dielectric constant, and others, such that it can be said that the characteristics of the laminate depend not only on the resins used, but also on the structure of the glass fabric. Pure unidirectional glass products used for advanced composites are known. A product of this kind consists of a series of undirectional yarns arranged next to one another. A unidirectional product of this type cannot be used for the manufacture of monolithic glass-reinforced resin laminates employing conventional technology on account of the difficulty in handling the layer of undirectional yarns and in particular the need for a substantial modification in the technique for molding the glass-reinforced resin sheets currently used. In fact, a layer of undirectional yarns held together by epoxy resin would be unable to withstand the standard molding pressures and the yarns, which will move during molding, would cause voids or irregular distribution between glass and resin. One solution to the problem is illustrated in the Applications EP 0478051 and WO 9402306, both in the name of Akzo, which provide a method for the manufacture of boards for printed circuits reinforced with a unidirectional glass product. These methods involve the use of extremely complex and costly machines. There is currently the need, therefore, for a glass fabric which is unidirectional as far as possible and can be processed with the technology available, but which is not affected by the aforementioned problems, in particular structural stability, and which is able to produce monolithic laminates which satisfy the requirements for printed circuits. SUMMARY OF THE INVENTION It has now been discovered that a unidirectional fabric produced with a continuous glass yarn which is twisted, has a low number of twists or zero twisting turns, with different gram weights and interlaced with thin glass yarns as a binding permits the manufacture of laminates for printed circuits satisfying the requirements imposed by progressive miniaturisation. Therefore, the present invention relates to a unidirectional fabric produced with continuous glass yarn which is twisted, has a low number of twists or zero twisting turns with different gram weights, characterized in that it is interlaced warpwise with glass yarns of 5.5 to 34 Tex at a spacing of up to 20 cm from each other and with a leno interwoven binding. The present invention also relates to the use of said glass fabric for the manufacture of laminates for printed circuits, as well as the printed circuits comprising said laminates. The present invention provides a fabric as a result of which it is possible to obtain monolithic glass-reinforced resin laminates possessing excellent properties for use in the manufacture of printed circuits using conventional techniques and equipment. This result is obtained owing to the stability of the unidirectional fabric according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS The subject of the present invention, in its various embodiments, and the advantages arising therefrom will be described in the detailed description which follows and with the aid of the drawings in which: FIG. 1 shows in schematic form an axonometric view of a conventional fabric; FIG. 2 shows a profile view of the fabric according to FIG. 1, along the section II--II; FIG. 3 shows in schematic form an axonometric view of the fabric according to the present invention; FIG. 4 shows a profile view of the fabric according to FIG. 3 along the section IV--IV; FIG. 5 shows a profile view of the fabric according to FIG. 3 along the section V--V. DETAILED DESCRIPTION OF THE INVENTION In the Figures, the reference (1) denotes the warp yarns, (2) the weft yarns and (3) the binding yarns. In the fabric according to the present invention, the interlacing warpwise binding yarn is obtained using glass yarns of 5.5 to 22 Tex. The two binding yarns lie, in pairs, next to the bottom of binding yarns and are not visible on the fabric. In the fabric these yarns (3) are interlaced with the yarns (2), being alternately located on the first weft on the upper right-hand side and on the second weft on the bottom left-hand side, resulting in a binding well known to textile experts by the name of "leno interwoven binding". With insertion of the binding yarns (3) which are referred to as "interlacing", stabilization of the bottom yarns is obtained, which allows handling of the unidirectional fabric without slipping of the yarns which could rise to overtensioning and very severe distortion during the subsequent resin impregnation phase. The yarns with this invention thus remain perfectly aligned with one another and uniformly tensioned, thus avoiding becoming displaced, superimposed or bunched together under the molding pressures occurring in the standard technological process used nowadays and resulting in a uniform resin/glass ratio in the mass of the laminate. In a first embodiment of the present invention, the unidirectional fabric is composed of yarn arranged warpwise of at least 90% of the total weight of the fabric. In the unidirectional fabric according to the present invention, the weft yarns (2) are considered solely to be bindings of the warp yarns (1). The interlacings may be arranged at a maximum spacing from one another of 20 cm. In a preferred embodiment a spacing of between 10 and 15 cm and a number of wefts of up to 8 per cm is envisaged. The yarn which forms the fabric is formed by conventional filaments, preferably with a diameter of between 5 and 13 microns. In a preferred embodiment, the yarn has a Tex value of between 22 and 136. A particularly preferred embodiment envisages a unidirectional fabric with a warp having a value of between 22 and 136, preferably 74 Tex, the weft with a value of between 11 and 68, preferably 34 Tex, and the interlacings with a value of between 5 and 34, preferably 11 Tex. The fabric according to the present invention may be processed perfectly using standard impregnation and molding processes with obvious economic advantages and without the need for investment in new technology. The laminates made of glass-reinforced resin, for example glass-reinforced epoxy resin, comprising the fabric according to the present invention as the support structure, have very low surface roughness values (Wt), less than 2 μm. By comparison, the roughness values of conventional laminates are 4 μm. With low roughness of the laminate, further reductions in the dimensions of the printed thin copper tracks become possible, with considerable advantages in terms of the overall performance of the panels, as well as direct application of the thin copper tracks, with major economic and ecological advantages. Using this system, it is possible to achieve savings in copper and eliminate the etching operation performed with toxic acids. With the present invention it is also possible to obtain dimensional stability values which are at least 60% lower than the current standard values equivalent to 200 ppm. This is possible owing to the intrinsic linearity of the unidirectional fabric which does not allow, as instead occurs in fabrics with a standard weave, elongations during molding of the laminate and consequent contractions during the ensuing processing stages. With low dimensional stability values, application of the dry film and in general manufacture of the multi-layers may be controlled more easily and therefore achieved in a more efficient and economical manner. Other advantages obtained with the laminates described above are the uniform perforability of the laminate with an improved perforation quality; greater economy of the perforating operation with savings in terms of the wear of the drilling tips; surface devoid of inclusions and excessive thicknesses which cause thinning of the copper; uniform thickness and composition of the laminate which helps achieve a more uniform "dielectric constant" over the entire printed circuit, in particular for applications involving high frequencies such as those of 3-30 GHz used in telecommunications and satellite applications; greater dimensional stability D stab -CTE α x ,y ; smaller number of microscopic voids; longer "measling" resistance times; greater economy during production of the fabric. The use of the novel unidirectional fabric also gives rise to advantages in connection with the laminate manufacturing process. Since the novel fabric has a wetting time which is 50% less compared to that of a standard fabric, the epoxy resin used during impregnation may be prepared with mixtures which are more viscous and hence contain a smaller quantity of solvent which is to be evaporated; consequently it is possible to achieve a higher working speed with a saving in the amount of solvent used. Moreover, the unidirectional fabric thus produced is particularly suitable for impregnation with hot-melt formulated resin systems and solvent-free resins, resulting in further savings in solvent, equivalent to nearly 100%, and even faster impregnation speeds. The present invention also provides a solution to the problem of imperfect cleanliness owing to the presence of the residues of organic compounds, such as starch, used in the weaving process and then removed. The presence of these residues in the laminate alters the chemical and physical properties of the latter. It is obvious that the standard fabrics are very compact and hence very difficult to clean owing to the difficulty which the heat has in penetrating them and hence the difficulty which the distillation vapors of the combusted size have in escaping. On the other hand, the fabric according to the present invention, owing to its greater permeability, allows optimum cleaning without the structure of the fabric being altered during the course of the operation.

A unidirectional fabric produced with a continuous glass yarn which is twisted, plied or has zero twisting turns, with different gram weights. Interlacings of thin glass binding yarns for stabilizing the fabric extend warpwise to engage weft yarns in a leno interweaving. The fabric is used in the manufacture of printed circuits and in industrial applications.

CROSS-REFERENCE TO RELATED APPLICATION This is a continuation application of application Ser. No. 09/629,362 filed Aug. 1, 2000, now U.S. Pat. No. 6,757,286 which was a continuation application of application Ser. No. 09/475,623 filed Dec. 30, 1999, now abandoned which was a continuation application of application Ser. No. 08/823,078 filed Mar. 24, 1997 which issued as U.S. Pat. No. 6,041,057. FIELD OF THE INVENTION The present invention relates to data communication networks. More particularly, the present invention relates to methods for configuring, maintaining connectivity in and utilizing an ATM network. BACKGROUND OF THE INVENTION A local area network (LAN) segment is a computer sub-network which includes multiple stations in the same physical area communicating by forwarding messages on a shared LAN media. Stations on different LAN segments in the same physical area often communicate through a shared LAN switching fabric, which selectively forwards messages received over the fabric to the destination LAN segment. Stations on different LAN segments in different physical areas, in contrast, often communicate over a backbone network which interconnects multiple LAN switches on the edge of the network. In such an arrangement, each LAN switch selectively forwards messages received over the backbone network to the destination LAN segment. Communication on LAN segments, and communication between LAN segments over LAN switches, is broadcast-oriented. A station desiring to communicate with another station on the same LAN segment does not need to know where the destination station is located on the segment. Instead, the source station relies on the broadcast capability of the LAN media to propagate all messages to all stations on the segment. An interface on the intended destination station captures the message. Other interfaces on the segment ignore the message. Similarly, if a message propagated on a LAN segment is destined for a station on a different LAN segment associated with the same LAN switch, the LAN switch interconnecting the two segments will typically capture and propagate the message on a switching fabric connecting the two segments. In turn, an interface on the LAN switch associated with the intended destination LAN segment captures and propagates the message on the segment. Other interfaces on the LAN switch ignore the message. Again, there is no requirement that the source station know where the intended destination station resides within the network for successful communication. Rather, communication between the stations on different LAN segments over the LAN switch is “seamless” because the stations can communicate as if they are on the same LAN segment. In contrast, communication over backbone networks is not always broadcast-oriented. One widely-used backbone technology is asynchronous transfer mode (ATM). Communicating over an ATM network requires that point-to-point or point-to-multipoint virtual connections be established between switches on the edge of the network. Thus, it is necessary for complete connectivity in ATM backbone networks to configure every source switch with virtual connections to every destination switch. Such configuration has generally required either manual configuration by a network administrator or implementation of ATM signaling procedures. Additional configuration has been required to maintain connectivity in the event an established link fails. As a result of these configuration and maintenance requirements, performance of ATM backbone networks has been hindered. ATM's configuration demands have become even greater with the advent of virtual local area networks (VLANs). A VLAN is an aggregate of LAN segments which are part of the same logical group, but not necessarily the same physical group. By limiting the flow of messages across VLAN boundaries in an ATM network, VLANs can conserve network bandwidth and enhance network security. However, VLANs can at the same time lessen network robustness by requiring configuration of additional overlay virtual connections. Robustness problems in ATM networks have been further exacerbated by using configuration services which by necessity or design give microprocessors, rather than custom logic, a primary role in message forwarding. Accordingly, there is a need for more efficient services for configuring and maintaining connectivity in ATM networks. SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved ATM network in which virtual connections are self-configuring. It is another object of the present invention to provide an improved ATM network in which multiple requests for virtual connections can be made in a single message. It is another object of the present invention to provide an improved ATM network in which a first set of virtual connections are self-configuring along a best path. It is another object of the present invention to provide improved ATM network in which a second set of virtual connections are self-configuring along a next-best path. It is another object of the present invention to provide an improved ATM network which can support multiple VLANs. It is another object of the present invention to provide an improved ATM network in which message forwarding is carried out primarily in custom logic. These and other objects of the present invention are achieved by methods for configuring and utilizing tagged virtual connections between source and destination switches on the edge of an ATM network. In one aspect of the invention, neighboring switches share topology information. Topology information includes switch identifying information and path cost information. Switch identifying information includes switch identifiers and VLAN information for particular switches. Path cost information includes information about the relative cost of using particular paths to reach particular switches. Topology information is shared by neighboring switches via topology messages. As a result of topology learning, switches learn about other switches and the most efficient paths for forwarding end-user messages to particular switches. In another aspect of the invention, neighboring switches enable links for tag switching. Link enablement is requested by forwarding hello requests. Hello requests include a range of tag values proposed for use on a particular link. Link enablement is established by forwarding hello responses. Hello responses include a positive or negative acknowledgment of a hello request. As a result of link enablement, switches learn the available links for use when requesting tagged virtual connections for forwarding end-user messages. In another aspect of the invention, edge switches and combination switches, as source switches, initiate requests for point-to-point tagged virtual connections to one another, as destination switches. Requests for point-to-point tagged virtual connections are initiated by forwarding a tag allocation request to a neighboring switch along the best path to a destination switch. Tag allocation requests include allocation information, including a source switch identifier, a destination switch identifier and a tag value. Source switches initiate a request for each destination switch for each shared VLAN. Multiple requests may be included in a single tag allocation message to conserve network bandwidth. Transit and combination switches, as neighboring switches, respond to each tag allocation request received by relaying a related tag allocation request to another neighboring switch, if any, along the best path to the destination switch. The relay process is repeated until a tag allocation request arrives at the destination switch. Switches select a different outbound tag value for each requested point-to-point virtual connection so that when an end-user message encoded with a particular tag value is subsequently presented for forwarding, the switch will be able to associate the message with a distinct virtual connection between a particular source and destination switch. As a result of point-to-point tag allocation, a full mesh of point-to-point virtual connections is established for forwarding known unicast end-user messages from source switches to destination switches using a simple look-up operation which resolves identifiers encoded in such messages to outbound ATM ports and outbound tags. In another aspect of the invention, edge switches and combination switches, as source switches, initiate requests for point-to-multipoint tagged virtual connections to one another, as destination switches. Requests for point-to-multipoint tagged virtual connections are initiated by forwarding a set of tag allocation requests to a set of neighboring switches along the spanning tree path to the set of destination switches sharing a VLAN with a source switch. Tag allocation requests include allocation information, including a source switch identifier, an identifier of the shared VLAN and a tag value. Source switches initiate a request for each shared VLAN. Each point-to-point multipoint tag allocation request is relayed by transit and combination switches, as neighboring switches, until a set of tag allocation requests arrives at the set of destination switches. As a result of point-to-multipoint tag allocation, a full mesh of point-to-multipoint virtual connections is established for forwarding broadcast, multicast and unknown unicast end-user messages from source switches to destination switches sharing a particular VLAN by performing a simple look-up operation using custom logic which resolves identifiers encoded in such messages to outbound ATM ports and outbound tags. In another aspect of the invention, end-user messages are forwarded from source switches to destination switches on the established point-to-point tagged virtual connections. On source switches, a destination switch identifier associated with an end-user message is resolved to a forwarding ATM port identifier and a first tag value. The message is forwarded over the forwarding ATM port to a neighboring switch. The neighboring switch resolves the first tag value to a forwarding ATM port identifier and second tag value and forwards the message over the forwarding ATM port to a second neighboring switch, if any. The resolution and forwarding process is repeated by additional neighboring switches, if any, until the end-user message arrives at the destination switch. The resolution and forwarding process may be advantageously implemented in custom logic using a table look-up operation. In another aspect of the invention, end-user messages are forwarded from source switches to destination switches on the established point-to-multipoint tagged virtual connections. On source switches, the VLAN identifier associated with an end-user message is resolved to a set of forwarding ATM port identifiers and a first set of tag values. The message is forwarded over the set of forwarding ATM ports to a set of neighboring switches. The neighboring switches resolve the first set of tag values to a set of forwarding ATM port identifiers and second set of tag values and forward the message over the set of forwarding ATM ports to a second set of neighboring switches, if any. The resolution and forwarding process is repeated by additional neighboring switches, if any, until the end-user message arrives at the set of destination switches belonging to the shared VLAN. The resolution and forwarding process may be advantageously implemented in custom logic using a table look-up operation. In another aspect of the invention, switches, in addition to initiating and relaying requests for point-to-point virtual connections to destination switches on the best paths, initiate and relay requests for point-to-point virtual connections on the next-best paths. As a result of next-best path tag allocation, if any best path link between a source and destination switch pair becomes disabled, an end-user message can be advantageously diverted to a next-best path to the destination switch. The present invention can be better understood by reference to the following detailed description, taken in conjunction with the accompanying drawings which are briefly described below. Of course, the actual scope of the invention is defined by the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic of a communication network operating in accordance with the present invention; FIG. 2 is a functional diagram of an edge switch operating in accordance with the present invention; FIG. 3 is a functional diagram of a transit switch operating in accordance with the present invention; FIG. 4 shows the general format of a topology message generated by a switch operating in accordance with the present invention; FIG. 5 shows the general format of a hello request message generated by a switch operating in accordance with the present invention; FIG. 6 shows the general format of a hello response message generated by a switch operating in accordance with the present invention; FIG. 7 shows the general format of a tag allocation message generated by a switch operating in accordance with the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 , a computer network 1 operating in accordance with a preferred embodiment of the present invention is shown. In the illustrated embodiment, network 1 includes stations S.sub. 1 , S.sub. 4 , S.sub. 5 interconnected to one another over ATM cloud 60 . ATM cloud is a connection-oriented medium characterized by switches and ATM links for forwarding information in fixed-length cells in accordance with governing ATM standards. Along the paths interconnecting stations S.sub. 1 , S.sub. 4 , S.sub. 5 are switches 10 , 20 , 30 , 40 , 50 . In the illustrated embodiment, network 1 includes edge switches 10 , 40 , transit switches 20 , 30 and combination switch 50 . It will be appreciated, however, that a network operating in accordance with the present invention may include two or more edge or combination switches and any number of transit switches interconnected by two or more sets of links. Edge switches are characterized by having one or more ports associated with LAN media, such as Ethernet, Token Ring or FDDI and one or more ports associated with an ATM cloud. In the illustrated embodiment, edge switch 10 has a LAN port associated with LAN segment 14 and station S.sub. 1 . Edge switch 40 has a LAN port associated with LAN segment 44 and station S.sub. 4 . Edge switches 10 , 40 also each have a single ATM port to ATM cloud 60 . Each edge switch port is associated with one or more VLANs. Transit switches are characterized by having two or more ATM ports associated with an ATM cloud. In the illustrated embodiment, transit switches 20 , 30 each have two ports to ATM cloud 60 . Combination switches are characterized by having one or more LAN ports associated with LAN media and two or more ATM ports associated with an ATM cloud. In the illustrated embodiment, combination switch 50 is associated with LAN segment 54 and station S.sub. 5 . Combination switch 50 also has two ATM ports to ATM cloud 60 . Each combination switch port is associated with one or more VLANs. Switches 10 , 20 , 30 , 40 , 50 are each assigned a unique switch identifier and are immediately interconnected to neighboring switches by links 12 , 23 , 24 , 25 , 35 . Links are preferably fiber optic or twisted pair cables supporting various bandwidths. FIGS. 2 and 3 present functional diagrams of switches operative in accordance with a preferred embodiment of the present invention. The illustrated functionality may be implemented using any suitable logic, although a custom logic implementation is preferred where indicated below. Referring to FIG. 2 , a functional diagram of an edge switch 200 operating in accordance with a preferred embodiment of the present invention is shown. Switch 200 includes TOP ADV means 210 . Means 210 serves to advertise network topology information to neighboring switches. Means 210 generates topology messages encoded with associated pairs of switch identifiers, path cost values and VLAN identifiers for switches in the network. Means 210 also periodically forwards topology messages to neighboring switches over active ATM ports of switch 200 . Path cost values encoded in topology messages reflect the aggregate cost of the links which must be traversed on a particular path over switch 200 to reach a particular switch. Path costs are added upon receipt of topology messages from neighboring switches. Thus, when switch 200 advertises its own path cost information to a neighboring switch, switch 200 assigns a path cost value of “0”. When the neighboring switch advertises the information learned about switch 200 , the neighboring switch assigns a path cost for switch 200 based on the bandwidth of the link on which the advertised information was received from switch 200 . Topology messages are forwarded periodically on active ATM ports of switch 200 . Switch 200 also includes TOP LRN means 220 . Means 220 serves to learn the topology of the network from topology information advertised by other switches. Means 220 assigns a path cost to each link on which topology messages are received, based on the bandwidth of the link. Means 220 further calculates aggregate path cost values by adding the path cost assigned to a link to the path cost value encoded in a topology message received on the link. Means 220 further associates the switch identifier and VLAN identifier in a received topology message with the aggregate path cost value and the identifier of the receiving ATM port and stores the information as an associated pair in a topology database. The topology database may be accessed using known memory access mechanisms. Switch 200 also includes LINK ENAB means 230 . Means 230 serves to determine if a neighboring switch is able to establish tagged virtual connections on a particular link. Means 230 determines from topology information whether a switch is a neighboring switch. Means 230 also associates a neighboring switch with a particular link. Means 230 further establishes a virtual connection to the neighboring switch on the link. Means 230 also forwards on the virtual connection a hello request message encoded with a range of tag values that switch 200 proposes to use when tag switching with the neighboring switch on the link. Means 320 further determines from information encoded in a hello response message received on the link whether the neighboring switch accepts or rejects the request to enable the link for tag switching with switch 200 . Switch 200 initiates a hello request message whenever switch 200 learns of a neighboring switch. Switch 200 also includes EDGE TAG SET means 240 . Means 240 serves to initiate requests for tagged point-to-point virtual connections for forwarding known unicast end-user messages. It will be appreciated that a known unicast message is a message encoded with information which switch 200 can resolve to a point-to-point tagged virtual connection to a particular destination switch. Means 240 determines from topology information whether a destination switch shares a VLAN with switch 200 . Means 240 also determines from topology information the forwarding ATM port on switch 200 associated with the best path to the destination switch. Means 240 further selects a tag value within the range of values available on the forwarding link. Means 240 further generates a tag allocation message encoded with a tag allocation request. The tag allocation request includes the selected tag value, the identifier of switch 200 and the identifier of the destination switch. Means 240 further forwards the tag allocation message to a neighboring switch on the forwarding link. Means 240 also serves to initiate requests for point-to-multipoint tagged virtual connections for forwarding broadcast, multicast and unknown unicast end-user messages. It will be appreciated that such messages are messages not encoded with information which switch 200 can resolve to a point-to-point tagged virtual connection to a particular destination switch. A point-to-multipoint tagged virtual connection is requested for each VLAN shared by switch 200 . Means 240 determines a set of forwarding ATM ports on switch 200 associated with the spanning tree path to a set of destination switches for a particular VLAN. Means 240 further selects a set of tag values within the range of values available on the set of forwarding links. Means 240 further generates a set of tag allocation messages encoded with a set of tag allocation requests for the set of destination switches. Each tag allocation request includes a selected tag value, the identifier of switch 200 and the identifier of the shared VLAN. Means 240 further forwards the set of tag allocation messages to a set of neighboring switches over the set of forwarding links. The Spanning Tree Protocol (STP) running in accordance with governing IEEE standards is preferably used to determine the spanning tree path. Means 240 also implements the foregoing procedures to initiate requests for point-to-point tagged virtual connections on the next-best path to destination switches. Means 240 further encodes multiple tag allocation requests in a single tag allocation message. Switch 200 initiates a point-to-point and a point-to-multipoint tag allocation request whenever switch 200 learns of a new VLAN shared by switch 200 and a destination switch. Edge switch 200 also includes EDGE TAG LRN means 250 . Means 250 serves to learn the tag values allocated by switch 200 for the requested tagged virtual connections. Means 250 associates a destination switch identifier with the forwarding ATM port identifier and the tag value encoded in an outbound tag allocation request for a point-to-point virtual circuit and stores the associated pair in a memory means. Means 250 also associates a set of tag values encoded in a set of outbound tag allocation requests for a point-to-multipoint virtual circuit with a set of forwarding ATM port identifiers and stores the associated pairs in a memory means. Means 250 also serves to learn the tag values allocated by neighboring switches for the tagged virtual connections for which switch 200 is a destination switch. Means 250 associates a tag value and a source switch identifier in a received point-to-point tag allocation request and stores the associated pair in a receiving database. Means 250 also associates a tag value and a source switch identifier in a received point-to-multipoint tag allocation request and stores the associated pair in a receiving database. Receiving databases may be accessed using known memory access mechanisms. Receiving databases advantageously enable switch 200 to perform a source learning operation on incoming end-user messages by providing switch 200 with information sufficient to resolve source station addresses encoded in such messages to particular source switch identifiers. Means 250 also, upon performing such a source learning operating, associates the learned source station address with a forwarding ATM port identifier and tag value previously stored in association with a particular destination switch identifier. Means 250 further stores the associated station address, forwarding ATM port identifier and tag value as a related pair in a forwarding database. Forwarding database on switch 200 may be accessed using known memory access mechanisms. Edge switch 200 also includes EDGE MSSG FWD means 260 . Means 260 serves to assign tag values to known unicast end-user messages and forward such messages along the established point-to-point tagged virtual connections. Means 260 resolves information encoded in a known unicast end-user message to a forwarding ATM port identifier and a first tag value retrieved from a forwarding database. Means 260 also encodes the message with the first tag value and forwards the message to a neighboring switch on the forwarding link. A look-up operation using custom logic is contemplated for retrieving information from the forwarding database. Custom logic may be implemented in an application-specific integrated circuit (ASIC). Means 260 also serves to assign tag values to broadcast, multicast, and unknown unicast end-user messages and forward such messages along the established point-to-multipoint tagged virtual connections. Means 260 resolves information encoded in a broadcast, multicast or unknown unicast end-user message to a set of forwarding ATM port identifiers and a set of first tag values retrieved from a memory means. Means also copies the end-user message. Means 260 also encodes the end-user message with the set of tag values and forwards the message to a set of neighboring switches on the set of forwarding links. Referring to FIG. 3 , a functional diagram of a transit switch 300 operating in accordance with a preferred embodiment of the present invention is shown. As with edge switch 200 , transit switch 300 has TOP ADV means 210 , TOP LRN means 220 and LINK ENAB means 230 . Switch 300 also includes TRANS TAG SET means 310 . Means 310 serves to relay requests for point-to-point tagged virtual connections initiated by source switches. Means 310 determines from topology information the forwarding ATM port on switch 300 associated with the best path to a destination switch. Means 310 further selects a tag value within the range of tag values available on the forwarding link. Means 310 further generates a tag allocation message encoded with a tag allocation request. Means 310 further forwards the tag allocation message to a neighboring switch on the forwarding link. Means 310 further implements the foregoing procedures to relay a request initiated by a source switch for a virtual connection on the next-best path to a destination switch. Means 310 further encodes multiple tag allocation requests in a single tag allocation message. Means 310 also serves to relay requests for point-to-multipoint tagged virtual connections initiated by a source switch. Means 310 determines the set of forwarding ATM ports on switch 300 associated with the spanning tree path to a set of destination switches. Means 310 further selects a set of tag values within the range of values available on a set of forwarding links. Means 310 further generates a set of tag allocation messages encoded with a set of tag allocation requests. Means 310 further forwards the set of tag allocation messages to a set of neighboring switches over the set of forwarding links. Switch 300 also includes TRANS TAG LRN means 320 . Means 320 serves to learn the tag values selected by upstream neighboring switches for the requested tagged point-to-point virtual connections. Means 320 associates a tag value encoded in an inbound tag allocation request with the an identifier of a forwarding ATM port and a tag value selected for encoding in an outbound tag allocation request and stores the associated pair in a forwarding database. Means 320 also serves to learn tag values selected by upstream neighboring switches for requested point-to-multipoint virtual connections. Means 320 associates a tag value encoded in an inbound tag allocation request with an identifier of a set of forwarding ATM ports and a set of tag values selected for encoding in an outbound tag allocation request and stores the associated pair in a forwarding database. Forwarding database on switch 300 may be accessed using known memory access mechanisms. Switch 300 also includes TRANS MSSG FWD means 330 . Means 330 serves to assign tag values to known unicast end-user messages and forward such messages along the established point-to-point virtual connections. Means 330 resolves a tag value encoded in an inbound end-user message to a forwarding ATM port identifier and an outbound tag value retrieved from a forwarding database. Means 330 also encodes an end-user message with the outbound tag value and forwards the message over the forwarding ATM port to a neighboring switch. Means 330 also serves to tag and forward messages along the established point-to-multipoint virtual connections. Means 330 resolves a tag value encoded in an inbound end-user message to a set of outbound ATM port identifiers and a set of outbound tag values retrieved from a forwarding database. Means 330 also encodes a set of end-user messages with the set of outbound tag values and forwards the set of end-user messages to a set of neighboring switches over the set of forwarding links. A look-up operation using custom logic is contemplated for retrieving information from the forwarding database. Custom logic may be implemented in an application-specific integrated circuit (ASIC). Combination switches combine the functionality of edge switch 200 and transit switch 300 in a single switch. Thus, combination switches include TOP ADV means 210 , TOP LRN means 220 , LINK ENAB means 230 , EDGE TAG SET means 240 , EDGE TAG LRN means 250 , EDGE MSSG FWD means 260 , TRANS TAG SET means 310 , TRANS TAG SET means 320 and TRANS MSSG FWD means 330 . Referring to FIG. 4 , the general format of a topology message 400 generated in accordance with a preferred embodiment of the present invention is shown. Message 400 includes a type field 410 encoded with a value identifying message 400 as a topology message. Message 400 includes version field 420 encoded with a value indicating the protocol version number of message 400 . Different protocol numbers may be used as enhancements are made to the protocol. Message 400 also includes flags field 430 indicating whether message 400 is a flash update message. Flash update messages contain topology information not included in previous topology messages. Message 400 further includes number of blocks (NOB) field 440 . NOB field 440 identifies the number of topology information blocks included in message 400 . Message 400 also includes “my switch” field 450 encoded with the identifier of the switch which generated the message 400 . Topology information blocks include topology information for a particular switch. One information block is included for each switch known to the switch which generated message 400 . Message 400 has first information block 460 . Block 460 includes subject switch field 470 encoded with the identifier of the particular switch which is the subject of the information in block 460 . Block 460 also has path cost field 472 . Path cost field 472 contains a value indicating the cost to reach the subject switch over the path that message 400 was received on. Path costs are assigned to each link based on the bandwidth of the link, with larger values assigned to slower links. In a preferred embodiment, a value of “1” indicates a 100 gigabit per second link, a value of “10” indicates a 10 gigabit per second link, a value of “100” indicates a 1 gigabit per second link, a value of “1000” indicates a 100 megabit per second link, a value of “10000” indicates a 10 megabit per second link, and so on, although it will be appreciated that it is the relationship between the values rather than the actual values which is significant. Block 460 also includes number of VLANs (NOV) field 474 . NOV field 474 contains a value indicating the number of VLANs active on the subject switch (and also the number of VLAN fields 476 , 478 to follow NOV field 474 ). VLAN fields 476 , 478 each contain an identifier of a VLAN active on the subject switch. It will be appreciated that message 400 may contain additional information blocks for additional switches having the same general format as block 460 . Referring to FIG. 5 , the general format of a hello request message 500 generated in accordance with a preferred embodiment of the present invention is shown. Message 500 includes a type field 510 encoded with a value identifying message 500 as a hello request message. Message 500 includes version field 520 encoded with a value indicating the protocol revision number of message 500 . Message 500 includes minimum tag value field 530 encoded with the lowest tag value available for use in tag switching on the link on which message 500 is forwarded. Message 500 also includes maximum tag value field 540 encoded with the largest tag value available for use in tag switching on the link on which message 500 is forwarded. Referring to FIG. 6 , the general format of a hello response message 600 generated in accordance with a preferred embodiment of the present invention is shown. Message 600 includes a type field 610 encoded with a value identifying message 600 as a hello response message. Message 600 includes version field 620 encoded with a value indicating the protocol revision number of message 600 . Message 600 also includes acknowledgment field 630 encoded with a value indicating whether the switch generated message 600 will enable the link on which message 600 is forwarded for tag switching with the neighboring switch which generated the hello request message to which message 600 is responsive. Referring to FIG. 7 , the general format of a tag allocation message 700 generated in accordance with a preferred embodiment of the present invention is shown. Message 700 includes type field 710 encoded with a value identifying message 700 as a tag allocation message. Message 700 includes version field 720 encoded with a value indicating the protocol revision number of message 700 . Message 700 also has a number of requests (NOR) field 730 encoded with a value indicating the number of tag allocation requests contained in message 700 . Message 700 also includes one or more allocation request blocks. First request block 740 contains a type field 742 encoded with a value indicating the requested virtual connection type. Point-to-point and point-to-multipoint are the contemplated types. Request block 740 also includes a source switch field 744 . Source switch field 744 is encoded with the identifier of the switch making the tag allocation request contained in the request block 740 . Request block 740 also includes destination switch field 746 . For requested point-to-point virtual connections, destination switch field 746 is encoded with the identifier of the destination switch. For requested point-to-multipoint virtual connections, field 746 is encoded with the identifier of the shared VLAN. Request block 740 further includes tag field 748 . Tag field 748 is encoded with the tag value selected by the switch which generated message 700 for forwarding end-user messages on the requested virtual connection. Message 700 may contain additional request blocks for additional requests having the same general format as block 740 . In a preferred embodiment of the present invention, tag-switched communication over ATM network is accomplished in four steps: topology learning, link enablement, tag allocation and message forwarding. Returning to FIG. 1 , in a preferred topology learning step, switches 10 , 20 , 30 , 40 , 50 periodically forward topology messages to neighboring switches on links 12 , 23 , 24 , 25 , 35 . Topology messages include switch information blocks including switch identifiers, path cost values and VLAN information for particular switches. Neighboring switches associate the information with the receiving link and store the associated pairs in their topology databases. As a result of topology learning, switches 10 , 20 , 30 , 40 , 50 learn the identity and VLAN membership and the most efficient paths for forwarding end-user messages to particular switches. The path associated with the lowest path cost to a particular switch over an enabled link is considered the best path to the particular switch. The path associated with the second lowest path cost to a particular switch over an enabled link is considered the next-best path to the particular switch. In a preferred link enablement step, switches 10 , 20 , 30 , 40 , 50 determine if neighboring switches are able to establish tagged virtual connections on the learned paths. Switches 10 , 20 , 30 , 40 , 50 forward hello request messages to neighboring switches on links 12 , 23 , 24 , 25 , 35 . In response to hello request messages, neighboring switches forward hello response messages accepting or rejecting the requests to enable links 12 , 23 , 24 , 25 , 35 for tag switching. In a preferred tag allocation step for point-to-point tagged virtual connections, edge switches 10 , 40 and combination switch 50 , as source switches, initiate requests for point-to-point virtual connections for forwarding known unicast messages to one another, as destination switches. A point-to-point tagged virtual connection is requested for each source and destination switch pair for each shared VLAN. Each tag allocation request includes the source switch identifier, the destination switch identifier and a first tag value. Each tag allocation request is forwarded to a neighboring transit or combination switch on the best path to the destination switch. The neighboring switch responds by generating a tag allocation request encoded with the source switch identifier, the destination switch identifier, and a second tag value and forwarding the request to a second neighboring switch, if any, on the best path to the destination switch. Similar messages are generated and forwarded by each additional neighboring switch, if any, on the best path, until a tag allocation request is received by the destination switch. Switches along the path of the requested point-to-point virtual connections store the tag allocation information in a memory means. On the source switch, the destination switch identifier, the forwarding ATM port identifier and the first tag value are associated and stored as an associated pair in a memory means. On each neighboring switch, the inbound tag value is associated with a forwarding ATM port identifier and the outbound tag value and stored as an associated pair in a forwarding database. On the destination switch, the source switch identifier, the receiving ATM port identifier and the inbound tag value are stored as an associated pair in a receiving database. In a more preferred tag allocation step, switches also initiate and relay requests for next-best path virtual connections to destination switches. Switches may be configured to initiate requests for next-best path virtual connections only if they are on the best path to a destination switch from the perspective of the source switch. Alternatively, switches may be configured to initiate requests for next-best path virtual connections if they are on the best or next-best path to the destination switch from the perspective of the neighboring switch from which a tag allocation request is received. Requests for next-best path virtual connections may be initiated concurrently with requests for best-path virtual connections. In a preferred tag allocation step for point-to-multipoint tagged virtual connections, edge switches 10 , 40 and combination switch 50 , as source switches, initiate requests for forwarding broadcast, multicast and unknown unicast messages to one another as destination switches. A tagged point-to-multipoint virtual connection is requested for each VLAN shared by the source switch. Each source switch generates a set of tag allocation requests encoded with the identifier of the source switch, the shared VLAN identifier, and a first set of tag values. The set of tag allocation requests is forwarded to a set of neighboring transit or combination switches on the spanning tree path to the set of destination switches belonging to the shared VLAN. The set of neighboring switches responds by generating and forwarding a second set of tag allocation requests encoded with the identifier of the source switch, the shared VLAN identifier, and a second set of tag values. The set of tag allocation requests is forwarded to a second set of neighboring switches, if any, on the spanning tree path to the set of destination switches. Similar messages are generated and forwarded by additional sets of neighboring switches, if any, on the spanning tree path, until a set of tag allocation requests is received by the set of destination switches belonging to the shared VLAN. Switches along the path of the requested point-to-multipoint virtual connections store the tag allocation information in memory. On the source switch, the shared VLAN identifier, the first set of forwarding ATM port identifiers and the first set of tag values are stored as associated pairs in a memory means. On the neighboring switches, the inbound set of tag values encoded in the received tag allocation requests are associated with a set of forwarding ATM port identifiers and an outbound set of tag values and stored as associated pairs in forwarding databases. On the set of destination switches, the shared VLAN identifier, the set of receiving ATM port identifiers and the inbound set of tag values encoded in the set of received tag allocation requests are stored as associated pairs in receiving databases. In a more preferred tag allocation step, multiple tag allocation requests are encoded in a single tag allocation message. In a preferred message forwarding step for point-to-point tagged virtual connections, end-user messages are forwarded on the established point-to-point virtual connections. On the source switch, the destination switch identifier associated with an end-user message is resolved to a forwarding ATM port identifier and a first tag value retrieved from a memory means. The message is encoded with the first tag value and forwarded over the forwarding ATM port to a neighboring switch. The neighboring switch retrieves from a forwarding database a forwarding ATM port identifier and second tag value associated with the first tag value. The neighboring switch generates a message encoded with the second tag value and forwards the message over the forwarding ATM port to a second neighboring switch, if any. Similar messages are generated and forwarded by additional neighboring switches, if any, on the best path, until the end-user message arrives at the destination switch. In a preferred message forwarding step for point-to-multipoint tagged virtual connections, end-user messages are forwarded on the established point-to-multipoint virtual connections. On the source switch, a broadcast, multicast or unknown unicast end-user message to be forwarded to the switches belonging to the shared VLAN is resolved to a first set of forwarding ATM port identifiers and a first set of tag values retrieved from a memory means. Copies of the message are made, as necessary, and encoded with the first set of tag values and forwarded over the first set of forwarding ports to a first set of neighboring switches. The neighboring switches retrieve from a forwarding database a second set of forwarding ATM port identifiers and a second set of tag values associated with the first set of tag values. The neighboring switches generate a second set of messages encoded with the second set of tag values and forward the messages over the second set of forwarding ATM ports to a second set of neighboring switches, if any. Similar messages are generated and forwarded by additional sets of neighboring switches, if any, on the spanning tree path, until the end-user messages arrive at the set of destination switches belonging to the shared VLAN. It will be appreciated that prior to forwarding messages must be segmented into a series of fixed-length cells in accordance with governing ATM standards. A preferred message forwarding step may be further illustrated by example by reference to FIG. 1 . For simplicity, it will be assumed that a single VLAN is active on all switch ports in network 1 . It will also be assumed that links 12 , 24 , 25 have a bandwidth of 100 megabits per second and that links 23 , 35 have a bandwidth of 1 gigabit per second and that all links are enabled. It will further be assumed that stations S.sub. 1 , S.sub. 4 and S.sub. 5 have been assigned unique media access control (MAC) addresses s.sub. 1 , s.sub. 4 and S.sub. 5 , respectively, and that the MAC addresses are only known to the particular switch disposed between the stations and the ATM cloud 60 . Thus, addresses s.sub. 1 , s.sub. 4 are unknown to switch 50 , addresses s.sub. 4 , s.sub. 5 are unknown to switch 10 and addresses s.sub. 1 , s.sub. 5 are unknown to switch 40 . First, consider an end-user message originating on source station S.sub. 1 intended for destination station S.sub. 5 . At station S.sub. 1 , the message is encoded with source address s.sub. 1 and unicast destination address s.sub. 5 and propagated on LAN segment 14 . The message arrives at source switch 10 due to the broadcast nature of LAN segment 14 . Source switch 10 , however, is unable to resolve address s.sub. 5 to a point-to-point tagged virtual connection to destination switch 50 . Therefore, source switch 10 resolves the message to the point-to-multipoint tagged virtual connection associated with the active VLAN. Accordingly, value t.sub.v associated with the spanning tree path to destination switches 40 and 50 is encoded in the message. The message is segmented into a series of ATM cells and forwarded on forwarding link 12 over the forwarding ATM port on source switch 10 . Upon arrival at neighboring switch 20 , the tag value t.sub.v encoded in the message is resolved to tag values t.sub.v′ and the forwarding ATM port associated with link 23 , which is on the spanning tree path to destination switches 40 , 50 . The message is encoded with tag value t.sub.v′ and forwarded on link 23 to neighboring switch 30 . Upon arrival at neighboring switch 30 , the tag value t.sub.v′encoded in the message is resolved to tag values t.sub.v″, t.sub.v′″ and the forwarding ATM port associated with links 24 , 35 , which are on the spanning tree path to destination switches 40 , 50 , respectively. One copy of the message is encoded with tag value t.sub.v″ and forwarded on link 24 to destination switch 40 . A second copy. of message is encoded with tag value t.sub.v ′″ and forwarded on link 35 to destination switch 50 . It will be appreciated that on neighboring switches 20 , 30 , the tag resolution process can be advantageously carried out by performing a table look-up operation using custom logic. Upon arrival at destination switch 50 , switch 50 performs a source learning operation which associates source station address s.sub. 1 with source switch 10 . The source learning process results in address s.sub. 1 becoming associated in a forwarding database with a forwarding ATM port identifier and a tag value t.sub. 1 for a point-to-point tagged virtual connection to switch 10 . Switch 50 also determines whether destination address s.sub. 5 is associated with a LAN segment immediately interconnected to switch 50 . Because destination address s.sub. 5 is associated with LAN segment 54 , the message is forwarded on LAN segment 54 and arrives at destination station S.sub. 5 . Upon arrival at destination switch 40 , switch 40 performs a source learning operation which associates source station address s.sub. 1 with source switch 10 . The source learning process results in address s.sub. 1 becoming associated in a forwarding database with a forwarding ATM port identifier and a tag value t.sub. 1 for a point-to-point tagged virtual connection to switch 10 . Now consider a reply end-user message originating on source station S.sub. 5 intended for destination station S.sub. 1 . At station S.sub. 5 , the message is encoded with source address s.sub. 5 and unicast destination address s.sub. 1 and propagated on LAN segment 54 . The message arrives at source switch 50 due to the broadcast nature of LAN segment 54 . Due to the source learning operation performed on the previous end-user message, source switch 50 is able to resolve address s.sub. 1 to a point-to-point tagged virtual connection to destination switch 10 . Accordingly, value t.sub. 1 associated with the best path to destination switch 10 is encoded in the message. The message is segmented into a series of ATM cells and forwarded on forwarding link 35 over the forwarding ATM port on source switch 50 . It will be appreciated that the address resolution process can be carried out on source switch 50 by performing a table look-up operation using custom logic. Upon arrival at neighboring switch 30 , the tag value t.sub. 1 ′ encoded in the message is resolved to tag values t.sub. 1 ′ and the forwarding ATM port associated with link 23 , which is on the best path to destination switch 10 . The message is encoded with tag value t.sub. 1 ′ and forwarded on link 23 to neighboring switch 20 . Upon arrival at neighboring switch 20 , the tag value t.sub. 1 ′ encoded in the message is resolved to tag value t.sub. 1 ″ and the forwarding ATM port associated with link 12 , which is on the best path to destination switch 10 . The message is encoded with tag value t.sub. 1 ″ and forwarded on link 12 to destination switch 10 . Upon arrival at destination switch 10 , switch 10 associates source station address s.sub. 5 with source switch 50 . Switch 10 also determines whether the destination address s.sub. 1 is associated with a LAN segment immediately connected to switch 10 . Because the destination address s.sub. 1 is associated with LAN segment 14 , the message is forwarded on LAN segment 14 and arrives at destination station S.sub. 1 . Custom logic look-up operations are contemplated for tag resolution on switches 30 , 20 , 10 . Now consider how the same reply message reaches destination switch S.sub. 1 in the event link 35 is disabled. At station S.sub. 5 , the message is encoded with source address s.sub. 5 and unicast destination address s.sub. 1 and propagated on LAN segment 54 . The message arrives at source switch 50 due to the broadcast nature of LAN segment 54 . Due to the source learning operation performed on the previous end-user message, source switch 50 is able to resolve address s.sub. 1 to a point-to-point tagged virtual connection to destination switch 10 . However, since link 35 is disabled, value t.sub. 1 nb associated with the next-best path to destination switch 10 is encoded in the message. The message is segmented into a series of ATM cells and forwarded on forwarding link 25 over the forwarding ATM port on source switch 50 . Upon arrival at neighboring switch 20 , the tag value t.sub. 1 nb encoded in the message is resolved to tag value t.sub. 1 nb′and the forwarding ATM port associated with link 12 , which is on the next-best path to destination switch 10 . The message is encoded with tag value t.sub. 1 nb′and forwarded on link 12 to destination switch 10 . Source learning and forwarding on destination switch 10 proceeds in the manner described above. It will be appreciated by those of ordinary skill in the art that the invention can be embodied in other specific forms without departing from the spirit or essential character hereof. The present description is therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.

Methods for configuring, maintaining connectivity in and utilizing an ATM network. Neighboring switches share topology information and enable links to neighboring switches for tag switching. Point-to-point tagged virtual connections are established between switches on the best and next-best paths learned from topology information. Point-to-multipoint tagged virtual connections are established on the spanning tree path. Multiple tag allocation requests are included in a single message to preserve bandwidth. Next-best paths are established to reduce latency in event of link failure. Forwarding operations may be performed in hardware to reduce latency during message forwarding.

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is based upon and claims priority to prior Japanese Patent Application No. 2009-23040 filed on Feb. 3, 2009 in the Japan Patent Office, the entire contents of which are incorporated herein by reference. FIELD [0002] Embodiments as described herein relate to a data transfer system, data transmitting apparatus, data receiving apparatus, and data transfer method. BACKGROUND [0003] In recent years, apparatuses in which multiple central processing units (CPUs) and high-capacity memories are mounted on one substrate are provided with the progress in semiconductor technologies and Large Scale Integrated Circuit (LSI) mounting technologies. Such apparatuses include, for example, blade servers. [0004] In such an apparatus, it is difficult to arrange the signal wirings between LSIs in substantially the same conditions, for example, to make all the signal wirings between LSIs substantially equal length because of mounting problems. Accordingly, variations in the transmission time of transmitting data from a data transmission side LSI to a data reception side LSI and variations in the wiring capacity arise between the bits on transmission signal wirings between LSIs. [0005] For example, skew or jitter is specifically known as such a variation. [0006] The variation mainly depends on, for example, characteristics of signal wirings functioning as the transmission paths on the board on which LSIs are mounted, the distance between the LSIs, the electric characteristics of connectors, and the signal drivability of the LSI chips. The variation becomes non-negligible with the increasing data transmission speed in recent years. Specifically, the variation makes the transmission with a higher reliability difficult. [0007] Accordingly, in recent years, in addition to signal wiring serving as a first transmission path used for the data transfer between LSIs, redundant signal wiring serving as a second transmission path is generally provided in order to realize the transmission with a higher reliability. [0008] For example, (1) data transfer by using the redundant signal wiring to perform error detection-correction with a function of, for example, parity or error check and correction (ECC)/cyclic redundancy check (CRC) or (2) data transfer in which the transmission path is duplicated is adopted. [0009] Which data transfer method is used is based on the tradeoff between the reliability and the cost. Specifically, a larger amount of redundant wiring is preferable for the data transfer and the cost is increased in order to improve the reliability. [0010] FIG. 12 illustrates an example of a data transfer process between LSIs in related art. In the example in FIG. 12 , N+1-bit data (data D[ 0 ] to D[N]) is transmitted from a transmission LSI 1210 to a reception LSI 1220 . [0011] In the transmission LSI 1210 , which is the data transmission side LSI, a data transmitter 1211 supplies the data D[ 0 ] to be transferred to a flip-flop (FF) 1212 - 0 . The FF 1212 - 0 supplies the data D[ 0 ] to a driver 1213 - 0 in synchronization with a clock signal CLK. [0012] The driver 1213 - 0 transmits the data D[ 0 ] to a receiver 1223 - 0 in the reception LSI 1220 , which is the data reception side LSI, through a data signal line 0 . A driver 1214 transmits the CLK to a receiver 1224 through a clock line. [0013] The receiver 1223 - 0 supplies the received data D[ 0 ] to an FF 1222 - 0 . The FF 1222 - 0 supplies the data D[ 0 ] to an error detection circuit 1225 in synchronization with the clock signal CLK supplied from the receiver 1224 . The error detection circuit 1225 supplies the data D[ 0 ] to a data receiver 1221 . [0014] The data D[ 1 ] to D[N] are also transmitted from the transmission LSI 1210 to the reception LSI 1220 in substantially the same manner. [0015] The data lines 0 to N and the clock line run on the boards having the transmission LSI 1210 and the reception LSI 1220 mounted thereon and run through connectors to connect the LSIs. Accordingly, the data signal wirings 0 to N and the clock line can be affected by, for example, various noises. [0016] The error detection circuit 1225 confirms whether the data D[ 0 ] to D[N] transmitted from the transmission LSI 1210 have been normally received. If an error is detected, the error detection circuit 1225 notifies information of the bit where the error has occurred to the data receiver 1221 , etc. [0017] Part or all of the data D[ 0 ] to D[N] received by the reception LSI 1220 are hereinafter referred to as “received data”. [0018] FIG. 13 is a flowchart illustrating an exemplary operation or state of the reception LSI 1220 . [0019] Referring to FIG. 13 , when the transmission LSI 1210 and the reception LSI 1220 are turned on, at S 1301 , the transmission LSI 1210 and the reception LSI 1220 normally start the data transfer process between the transmission LSI 1210 and the reception LSI 1220 . [0020] At S 1302 , the error detection circuit 1225 detects a one-bit error in the received data. At S 1303 , the error detection circuit 1225 uses a one-bit error correction function to correct the one-bit error. [0021] At S 1304 , the error detection circuit 1225 detects a new one-bit error. In this case, the error detection circuit 1225 cannot restore the received data in which the one-bit error has occurred to normal data because of the limitation of the error correction function. Accordingly, in Step S 1305 , the reliability of the data transferred between the transmission LSI 1210 and the reception LSI 1220 is reduced. [0022] As a result, at S 1306 , the data transfer between the transmission LSI 1210 and the reception LSI 1220 is stopped. At S 1307 , the operation of the entire information processing system including the transmission LSI 1210 and the reception LSI 1220 is stopped. [0023] [Patent Document 1] Japanese Laid-Open Patent Publication No. 05-268339 [0024] [Patent Document 2] Japanese Laid-Open Patent Publication No. 2000-078166 SUMMARY [0025] According to an aspect of the invention, there is provided a data transfer system transmitting and receiving data through a first transmission path and a second transmission path, the data transferring system includes a first apparatus that transmits data through the first transmission path and a second apparatus that receives the data from the first apparatus through the first transmission path, the second apparatus transmits error bit information about the bit position of an error, wherein when the first apparatus receives the error bit information from the second apparatus, the first apparatus transmits switching bit information concerning the bit position which is identified by the error bit information and the transmission path of which is switched to the second transmission path and the data on the bit position identified by the error bit information to the second apparatus through the second transmission path, and the second apparatus receives the data on the bit position identified by the switching bit information. [0026] It is to be understood that both the foregoing summary description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS [0027] FIG. 1 illustrates an example of the configuration of the main part of a data transfer system realizing a data transfer method according to an embodiment of the present invention; [0028] FIG. 2 illustrates a specific example of the configuration of a selection circuit according to an embodiment; [0029] FIG. 3 illustrates a specific example of the configuration of an error detection-switching circuit according to an embodiment; [0030] FIG. 4 illustrates a specific example of the configuration of an error bit notification-switching determination circuit according to an embodiment; [0031] FIG. 5 is a flowchart illustrating the outline of a process of switching to a spare line according to an embodiment; [0032] FIG. 6 is a flowchart illustrating an example of a process of switching to the spare line in a reception LSI according to an embodiment; [0033] FIG. 7 is a flowchart illustrating an example of a process of switching to the spare line in a transmission LSI according to an embodiment; [0034] FIG. 8 is a time chart of the main signals when the number of error occurrences of transmission data exceeds a line switching threshold value; [0035] FIG. 9 illustrates a modification of the configuration realizing the data transfer method according to an embodiment; [0036] FIG. 10 illustrates a specific example of the configuration of a selection circuit when multiple spare lines are used; [0037] FIG. 11 illustrates a specific example of the configuration of an error detection-switching circuit when multiple spare lines are used; [0038] FIG. 12 illustrates an example of a data transfer process between LSIs in a related art; and [0039] FIG. 13 is a flowchart illustrating an exemplary operation or state of a reception LSI in FIG. 12 . DESCRIPTION OF EMBODIMENTS [0040] FIG. 1 illustrates an example of the configuration of a data transfer system 100 realizing a data transfer method according to an embodiment. [0041] The data transfer system 100 includes a transmission LSI 110 transmitting N+1-bit data D composed of a plurality of one-bit-width data D[ 0 ]to D[N] and a reception LSI 120 receiving the data D transmitted from transmission LSI 110 . [0042] The data composed of the data D[ 0 ] to D[N] is hereinafter referred to as the “data D.” The figures in square brackets of the data D[ 0 ] to D[N] represent the bit positions in the data D. For example, the data D[ 0 ] represents data at a bit 0 of the data D. “N” denotes a natural number including zero. [0043] The transmission LSI 110 is connected to the reception LSI 120 so as to be capable of communicating with the reception LSI 120 via data lines 0 , 1 , . . . , and N, a spare line, a clock line, and an error-bit information line. [0044] The data lines 0 , 1 , . . . , and N are used to transmit the data D[ 0 ], D[ 1 ], . . . , and D[N]. The spare line is provided for a spare of the data lines and is used to transmit one-bit-width data. The clock line is used to transmit a clock signal CLK. The error-bit information line is used to transmit, for example, error bit information E described below. [0045] The transmission LSI 110 includes a selection circuit 111 , flip-flops (FFs) 112 - 0 to 112 -N, drivers 113 - 0 to 113 -N, a driver 114 , a receiver 115 , an FF 116 , and a driver 117 . [0046] The selection circuit 111 is connected to data input lines 0 , 1 , . . . , and N that are connected to another LSI or the like. The output terminal of the selection circuit 111 is connected to the FFs 112 - 0 , 112 - 1 , . . . , and 112 -N and the FF 116 . The output terminal of a clock-signal generation circuit (not illustrated) generating the clock signal CLK is also connected to the FFs 112 - 0 , 112 - 1 , . . . , and 112 -N and the FF 116 . [0047] The output terminals of the FFs 112 - 0 , 112 - 1 , . . . , and 112 -N and the FF 116 are connected to the drivers 113 - 0 , 113 - 1 , . . . , and 113 -N and the driver 117 , respectively. [0048] The output terminals of the drivers 113 - 0 , 113 - 1 , . . . , and 113 -N, the driver 114 , and the driver 117 are connected to the data lines 0 , 1 , . . . , and N, the clock line, and the spare line, respectively. [0049] The driver 114 is connected to the output terminal of the clock-signal generation circuit (not illustrated). [0050] The output terminal of the receiver 115 is connected to the selection circuit 111 . The receiver 115 is also connected to the error-bit information line. [0051] The reception LSI 120 includes receivers 121 - 0 to 121 -N, FFs 122 - 0 to 122 -N, a receiver 123 , an error detection-switching circuit 124 , an error bit notification-switching determination circuit 125 , a driver 126 , a receiver 127 , and an FF 128 . [0052] The receivers 121 - 0 , 121 - 1 , . . . , and 121 -N, the receiver 123 , and the receiver 127 are connected to the data lines 0 , 1 , . . . , and N, the clock line, and the spare line, respectively. [0053] The output terminals of the receivers 121 - 0 , 121 - 1 , . . . , and 121 -N and the receiver 127 are connected to the FFs 122 - 0 , 122 - 1 , . . . , and 122 -N and the FF 128 , respectively. [0054] The output terminals of the FFs 122 - 0 , 122 - 1 , . . . , and 122 -N are connected to the error detection-switching circuit 124 . The error detection-switching circuit 124 is connected to data output lines 0 , 1 , . . . , and N that are connected to another LSI or the like. [0055] The output terminal of the receiver 123 is connected to the FFs 122 - 0 , 122 - 1 , . . . , and 122 -N and the FF 128 . [0056] Among the output terminals of the error detection-switching circuit 124 , the output terminals through which the data D is outputted are connected to the other LSI or the like connected to the reception LSI 120 . Among the output terminals of the error detection-switching circuit 124 , the output terminals through which the error bit information E and a switching completion notification are outputted are connected to the error bit notification-switching determination circuit 125 . [0057] The output terminal of the error bit notification-switching determination circuit 125 is connected to the driver 126 . The output terminal of the driver 126 is connected to the error-bit information line. [0058] The transmission LSI 110 having the above configuration performs a data transmitting process described below. [0059] The selection circuit 111 receives the N+1-bit data D[ 0 ] to D[N] transmitted from the other LSI or the like. For example, the selection circuit 111 supplies the received data D[ 0 ] to the FF 112 - 0 . [0060] The FF 122 - 0 holds the data D[ 0 ] received from the selection circuit 111 . The FF 122 - 0 supplies the data D[ 0 ] to the driver 113 - 0 in synchronization with the clock signal CLK. [0061] The driver 113 - 0 transmits the data D[ 0 ] supplied from the FF 112 - 0 to the receiver 121 - 0 through the data line 0 . [0062] The transmission LSI 110 transmits the data D[ 0 ] to the reception LSI 120 through the above operation. [0063] The transmission LSI 110 transmits the data D[ 1 ], D[ 2 ], . . . , and D[N] to the receiver 121 - 1 , 121 - 2 , . . . , and 121 -N, respectively, through similar operations. [0064] For example, the selection circuit 111 supplies the data D[N] to the FF 112 -N. The FF 122 -N holds the data D[N] received from the selection circuit 111 . The FF 122 -N supplies the data D[N] to the driver 113 -N in synchronization with the clock signal CLK. [0065] The driver 113 -N transmits the data D[N] supplied from the FF 112 -N to the receiver 121 -N through the data line N. [0066] The driver 114 transmits the clock signal CLK to the receiver 123 through the clock line. [0067] The reception LSI 120 performs a data receiving process described below. [0068] For example, the receiver 121 - 0 receives the data D[ 0 ] transmitted from the driver 113 - 0 through the data line 0 . The receiver 121 - 0 supplies the received data D[ 0 ] to the FF 122 - 0 . The FF 122 - 0 holds the data D[ 0 ] supplied from the receiver 121 - 0 . [0069] The receiver 123 supplies the clock signal CLK transmitted through the clock line to the FFs 122 - 0 , 122 - 1 , . . . , and 122 -N and the FF 128 . [0070] The FF 122 - 0 supplies the data D[ 0 ] to the error detection-switching circuit 124 in synchronization with the clock signal CLK supplied from the receiver 123 . [0071] The reception LSI 120 receives the data D[ 0 ] transmitted from the transmission LSI 110 through the above operation. [0072] The reception LSI 120 receives the data D[ 1 ], D[ 2 ], . . . , and D[N] transmitted from the transmission LSI 110 through similar operations. [0073] For example, the receiver 121 -N receives the data N[N] transmitted from the driver 113 -N through the data line N. The receiver 121 -N supplies the received data D[N] to the FF 122 -N. [0074] The FF 122 -N holds the data D[N] supplied from the receiver 121 -N. The FF 122 -N supplies the data D[N] to the error detection-switching circuit 124 in synchronization with the clock signal CLK supplied from the receiver 123 . [0075] The error detection-switching circuit 124 determines whether an error occurred in the N+1-bit data D composed of the one-bit-width data D[ 0 ] to D[N]. The error detection-switching circuit 124 counts the number of error occurrences for every bit. [0076] The bit in which an error has occurred is called an error bit. A case in which the error bit is “i” will be described, where “i” denotes a natural number that includes zero and is not larger than N. [0077] The error detection-switching circuit 124 determines whether an error occurred in the data D by using, for example, the parity or the ECC/CRC function. [0078] If no error is detected, the error detection-switching circuit 124 outputs the data D of each bit to the data output lines 0 , 1 , . . . , and N. [0079] If an error is detected, the error detection-switching circuit 124 generates the error bit information E and notifies the error bit notification-switching determination circuit 125 of the error bit information E. Here, the error detection-switching circuit 124 may output the data D of each bit to the data output lines 0 , 1 , . . . , and N. [0080] The “error bit information E” indicates information identifying the error bit in the data D detected by the error detection-switching circuit 124 . [0081] Upon the reception of the notification of the error bit information E from the error detection-switching circuit 124 , the error bit notification-switching determination circuit 125 counts the number of error occurrences at the error bit. For example, if an error has occurred in the data D[i], the error bit notification-switching determination circuit 125 counts and stores the number of error occurrences at the bit i. [0082] If the number of error occurrences at the error bit i is larger than or equal to a predetermined value, the error bit notification-switching determination circuit 125 encodes the error bit information E into serial data and supplies the encoded error bit information E to the driver 126 . [0083] The driver 126 transmits the error bit information E to the receiver 115 through the error-bit information line. The receiver 115 supplies the error bit information E transmitted from the driver 126 to the selection circuit 111 . [0084] Upon the reception of the error bit information E from the receiver 115 , the selection circuit 111 decodes the error bit information E in the serial data to identify the error bit i. The selection circuit 111 switches the destination of the data D[i] at the error bit i from the FF 112 - i to the FF 116 . [0085] At substantially the same time, the selection circuit 111 generates switching bit information and supplies the switching bit information to the FF 116 . The “switching bit information” concerns the bit position in the data D identifying the bit having a destination which is switched to the FF 116 via the spare line. Accordingly, when the error bit information indicates “i”, the switching bit information also indicates “i”. [0086] Then, the selection circuit 111 supplies the data D[ 0 ], D[ 1 ], . . . , and D[N] received from the other LSI or the like to the FFs 112 - 0 , 112 - 1 , . . . , and 112 -N, respectively. However, the selection circuit 111 supplies only the data D[i] to the FF 116 . [0087] The FF 116 holds the switching bit information supplied from the selection circuit 111 . The FF 116 supplies the switching bit information to the driver 117 in synchronization with the clock signal CLK. The driver 117 transmits the switching bit information to the receiver 127 through the spare line. [0088] Upon the reception of the switching bit information from the driver 117 , the receiver 127 supplies the switching bit information to the FF 128 . The FF 128 holds the switching bit information. The FF 128 supplies the switching bit information to the error detection-switching circuit 124 in synchronization with the clock signal CLK supplied from the receiver 123 . [0089] The data D[i] is transmitted from the selection circuit 111 to the error detection-switching circuit 124 in a process similar to that for the switching bit information. The data D excluding the data D[i] is transferred in the manner described above. [0090] Upon the reception of the switching bit information from the FF 128 , the error detection-switching circuit 124 switches the data line i through which the data D[i] at the bit i identified by the switching bit information is transferred to the spare line. Then, the error detection-switching circuit 124 supplies the switching completion notification to the error bit notification-switching determination circuit 125 . [0091] The error bit notification-switching determination circuit 125 supplies the received switching completion notification to the driver 126 . The driver 126 transmits the switching completion notification to the receiver 115 through the error-bit information line. [0092] FIG. 2 illustrates a specific example of the configuration of the selection circuit 111 according to one embodiment. [0093] The selection circuit 111 includes a switching-bit specifying circuit 201 , a switching-signal selection circuit 202 , a switching code-switching bit information generation circuit 203 , and a selector 204 . [0094] The switching-signal selection circuit 202 includes AND circuits 202 a - 0 , 202 a - 1 , . . . , and 202 a -N and an OR circuit 202 b. [0095] The switching-bit specifying circuit 201 and the switching code-switching bit information generation circuit 203 are connected to the output terminal of the receiver 115 . [0096] The data input lines 0 , 1 , . . . , and N are connected to the AND circuits 202 a - 0 , 202 a - 1 , . . . , and 202 a -N, respectively. The data input lines 0 , 1 , . . . , and N are also connected to the FFs 112 - 0 , 112 - 1 , . . . , and 112 -N, respectively. [0097] One end of each of switching bit specifying lines 0 , 1 , . . . , and N described below is connected to the switching-bit specifying circuit 201 . The other ends of the switching bit specifying lines 0 , 1 , . . . , and N are connected to the AND circuits 202 a - 0 , 202 a - 1 , . . . , and 202 a -N, respectively. [0098] The output terminals of the AND circuits 202 a - 0 , 202 a - 1 , . . . , and 202 a -N are connected to the OR circuit 202 b . The output terminal of the OR circuit 202 b and the output terminal of the switching code-switching bit information generation circuit 203 are connected to the selector 204 . The output terminal of the selector 204 is connected to the FF 116 . [0099] In the above configuration, if the switching-bit specifying circuit 201 detects an error occurrence code described below, the switching-bit specifying circuit 201 receives the error bit information E from the receiver 115 which is transmitted from the error bit notification-switching determination circuit 125 after the error occurrence code is transmitted by the error bit notification-switching determination circuit 125 . [0100] Then, the switching-bit specifying circuit 201 decodes the error bit information E transmitted as the serial data to identify the error bit. The switching-bit specifying circuit 201 generates switching-bit specifying data S for specifying the data line to be switched to the spare line. The switching-bit specifying circuit 201 supplies the switching-bit specifying data S to the switching-signal selection circuit 202 . [0101] The switching-bit specifying data S has the same bit width as that of the data D received from the other LSI or the like. Since the data D according to one embodiment has a bit width of N+1 bit, the switching-bit specifying data S also has a bit width of N+1 bit. In other words, the switching-bit specifying data S is composed of a plurality of one-bit-width data S[ 0 ], S[ 1 ], . . . , and S[N]. The figures in square brackets of the one-bit-width data S[ 0 ], S[ 1 ], . . . , and S[N] represent the bit positions in the switching-bit specifying data S. [0102] For example, when the error bit is “i”, the switching-bit specifying circuit 201 generates the switching-bit specifying data S in which only the data S[i] is set to “1” and the data S[ 0 ], S[ 1 ], . . . , and S[N] excluding the data S[i] are set to “0”. [0103] The switching-bit specifying circuit 201 supplies the switching-bit specifying data S[ 0 ], S[ 1 ], . . . , and S[N] to the AND circuits 202 a - 0 , 202 a - 1 , . . . , and 202 a -N, respectively. [0104] In the switching-signal selection circuit 202 , for example, the AND circuit 202 a - 0 supplies a result of the logical AND operation of the data D[ 0 ] supplied through the data input line 0 and the switching-bit specifying data S[ 0 ] supplied from the switching-bit specifying circuit 201 to the OR circuit 202 b. [0105] The remaining AND circuits 202 a - 1 , 202 a - 2 , . . . , and 202 a -N supply the logical ANDs to the OR circuit 202 b in similar processes, respectively. [0106] For example, the AND circuit 202 a -N supplies a result of the logical AND operation of the data D[N] supplied through the data input line N and the switching-bit specifying data S[N] supplied from the switching-bit specifying circuit 201 to the OR circuit 202 b. [0107] The OR circuit 202 b supplies a result of the logical OR operation of the outputs from the AND circuits 202 a - 0 , 202 a - 1 , . . . , and 202 a -N to the selector 204 . [0108] When the switching code-switching bit information generation circuit 203 detects the error occurrence code described below, the switching code-switching bit information generation circuit 203 receives the error bit information E from the receiver 115 which is transmitted from the error bit notification-switching determination circuit 125 after the error occurrence code is transmitted by the error bit notification-switching determination circuit 125 . [0109] Then, the switching code-switching bit information generation circuit 203 decodes the error bit information E transmitted as the serial data to identify the error bit. The switching code-switching bit information generation circuit 203 generates the switching bit information for specifying the data line to be switched to the spare line. [0110] The switching code-switching bit information generation circuit 203 generates a switching code and encodes the switching bit information into serial data. The switching code-switching bit information generation circuit 203 supplies the switching code and the switching bit information to the selector 204 . Here, the switching code-switching bit information generation circuit 203 outputs the switching bit information after the switching code is outputted by the switching code-switching bit information generation circuit 203 . [0111] The switching code is used for notifying the reception LSI 120 that one of the data lines is switched to the spare line. Accordingly, the switching code may be an arbitrary predetermined code as long as the switching code may be distinguished from other data. [0112] When the output signal is received from the switching code-switching bit information generation circuit 203 , the selector 204 selects the output signal from the switching code-switching bit information generation circuit 203 and supplies the selected output signal to the FF 116 . When no output signal is received from the switching code-switching bit information generation circuit 203 , the selector 204 supplies the output signal from the OR circuit 202 b to the FF 116 . [0113] FIG. 3 illustrates a specific example of the configuration of the error detection-switching circuit 124 according to an embodiment. [0114] The error detection-switching circuit 124 includes selectors 301 - 0 to 301 -N, an error detection-correction circuit 302 , a switching-timing generation circuit 303 , and an OR circuit 304 . [0115] The output terminals of the FFs 122 - 0 , 122 - 1 , . . . , and 122 -N are connected to the selectors 301 - 0 , 301 - 2 , . . . , and 301 -N, respectively. The output terminal of the FF 128 is connected to the selectors 301 - 0 , 301 - 1 , . . . , and 301 -N and the switching-timing generation circuit 303 . [0116] The output terminal of the switching-timing generation circuit 303 is connected to the selectors 301 - 0 , 301 - 1 , . . . , and 301 -N. The output terminal of the switching-timing generation circuit 303 is also connected to the OR circuit 304 . [0117] One-bit-width data is transmitted through the lines connecting the switching-timing generation circuit 303 to the selectors 301 - 0 , 301 - 1 , . . . , and 301 -N. The switching-timing generation circuit 303 supplies switching instruction data I[ 0 ], I[ 1 ], . . . , and I[N] described below to the selectors 301 - 0 , 301 - 1 , . . . , and 301 -N, respectively. [0118] The output terminals of the selectors 301 - 0 , 301 - 1 , . . . , and 301 -N are connected to the error detection-correction circuit 302 . [0119] Among the output terminals of the error detection-correction circuit 302 , the output terminals through which the data D is outputted are connected to the data output lines 0 , 1 , . . . , and N connected to the other LSI or the like (not illustrated). [0120] The error-bit information line through which the error bit information E is outputted, among the output terminals of the error detection-correction circuit 302 , is connected to the error bit notification-switching determination circuit 125 . [0121] The output terminal of the OR circuit 304 is connected to the error bit notification-switching determination circuit 125 . [0122] In the above configuration, for example, the selector 301 - 0 selects the output signal from the FF 128 if the switching instruction data I[ 0 ] supplied from the switching-timing generation circuit 303 is set to “1”. The selector 301 - 0 selects the output signal from the FF 122 - 0 if the switching instruction data I[ 0 ] is set to “0”. The selector 301 - 0 supplies the selected signal to the error detection-correction circuit 302 . [0123] The remaining selectors 301 - 1 , 301 - 2 , . . . , and 301 -N perform similar operations. For example, the selector 301 -N selects the output signal from the FF 128 if the switching instruction data I[N] is set to “1”. The selector 301 -N selects the output signal from the FF 122 -N if the switching instruction data I[N] is set to “0”. The selector 301 -N supplies the selected signal to the error detection-correction circuit 302 . [0124] The error detection-correction circuit 302 receives the data D[ 0 ], D[ 1 ], . . . , and D[N] supplied from the selectors 301 - 0 , 301 - 1 , . . . , and 301 -N, respectively. The error detection-correction circuit 302 performs an error checking process on the N+1-bit data D composed of the data D[ 0 ], D[ 1 ], . . . , and D[N]. [0125] For example, the error detection-correction circuit 302 performs the error checking process by using the parity or the ECC/CRC function. [0126] If no error is detected, the error detection-correction circuit 302 supplies the data D of each bit to the data output lines 0 , 1 , . . . , and N. For example, the error detection-correction circuit 302 outputs the data D[ 0 ] to the data output line 0 and outputs the data D[ 1 ] to the data output line 1 , respectively. [0127] If an error is detected, the error detection-correction circuit 302 generates the N+1-bit error bit information E in which the error bit is set to “1” and the other bits are set to “0”. Accordingly, the error bit information E is composed of a plurality of one-bit-width data E[ 0 ], E[ 1 ], . . . , and E[N]. For example, the data E[ 0 ] that is set to “1” indicates that an error occurs in the data D[ 0 ]. [0128] After generating the error bit information E, the error detection-correction circuit 302 supplies the error bit information E to the error bit notification-switching determination circuit 125 . [0129] When the switching-timing generation circuit 303 detects the switching code from the output signal from the FF 128 , the switching-timing generation circuit 303 acquires the switching bit information transmitted from the FF 118 after the switching code is transmitted from the FF 128 . [0130] After acquiring the switching bit information, the switching-timing generation circuit 303 generates the N+1-bit switching instruction data I in which the bit indicated in the switching bit information is set to “1” and the other bits are set to “0”. The switching instruction data I is composed of the one-bit-width data I[ 0 ], I[ 1 ], . . . , and I[N]. For example, the data I[ 0 ] that is set to “1” indicates that the data line 0 is to be switched to the spare line. [0131] After generating the switching instruction data I, the switching-timing generation circuit 303 supplies the switching instruction data I of each bit to the selectors 301 - 0 , 301 - 1 , . . . , and 301 -N, respectively. For example, the switching-timing generation circuit 303 supplies the switching instruction data I[ 0 ] to the selector 301 - 0 , supplies the switching instruction data I[ 1 ] to the selector 301 - 1 , . . . , and supplies the switching instruction data I[N] to the selector 301 -N. [0132] In addition, the switching-timing generation circuit 303 supplies the switching instruction data Ito the OR circuit 304 . The OR circuit 304 supplies a result of the logical OR operation of the data I[ 0 ], I[ 1 ], . . . , and I[N] composing the switching instruction data I to the error bit notification-switching determination circuit 125 . The logical OR output from the OR circuit 304 is used as the “switching completion notification”. [0133] FIG. 4 illustrates a specific example of the configuration of the error bit notification-switching determination circuit 125 according to an embodiment. [0134] The error bit notification-switching determination circuit 125 includes a number-of-error-occurrences counter circuit 401 , a line-switching threshold-value storage circuit 402 , a threshold value comparison-error bit information notification circuit 403 , and a selector 404 . [0135] The number-of-error-occurrences counter circuit 401 is connected to the error detection-switching circuit 124 via the error-bit information line. The output terminal of the number-of-error-occurrences counter circuit 401 and the output terminal of the line-switching threshold-value storage circuit 402 are connected to the threshold value comparison-error bit information notification circuit 403 , respectively. [0136] The selector 404 connects the output terminal of the threshold value comparison-error bit information notification circuit 403 to a switching completion notification line used for notifying that the switching has been performed by the error detection-switching circuit 124 . [0137] In the above configuration, when the number-of-error-occurrences counter circuit 401 receives the error bit information E from the error detection-switching circuit 124 , the number-of-error-occurrences counter circuit 401 refers to each bit of the error bit information E. The error detection-switching circuit 124 detects the bit that is set to “1” from the referred error bit information E to identify the error bit. [0138] After identifying the error bit, the number-of-error-occurrences counter circuit 401 adds one to the number of error occurrences of the error bit stored in a number-of-error-occurrences storage part (not illustrated) provided in the number-of-error-occurrences counter circuit 401 . [0139] The number-of-error-occurrences counter circuit 401 notifies the threshold value comparison-error bit information notification circuit 403 of the error bit information E and the number of error occurrences. [0140] Upon the reception of the notification of the number of error occurrences from the number-of-error-occurrences counter circuit 401 , the threshold value comparison-error bit information notification circuit 403 receives a line switching threshold value from the line-switching threshold-value storage circuit 402 . The line-switching threshold-value storage circuit 402 stores a threshold value used as a reference value in determination of whether the data line transferring data of a bit position where an error has occurred is to be switched to the spare line. This threshold value is called as “line switching threshold value”. [0141] Then, the threshold value comparison-error bit information notification circuit 403 compares the number of error occurrences with the line switching threshold value. If the number of error occurrences is larger than or equal to the line switching threshold value, the threshold value comparison-error bit information notification circuit 403 generates the error occurrence code, encodes the error bit information E into serial data, and supplies the error occurrence code and the error bit information E to the selector 404 . [0142] The error occurrence code is used to indicate that errors have occurred in the transmission LSI 110 a number of times that is larger than or equal to the line switching threshold value. Accordingly, the error occurrence code may be an arbitrary predetermined code as long as the error occurrence code may be distinguished from other data. [0143] After generating the error occurrence code, the threshold value comparison-error bit information notification circuit 403 outputs the switching bit information E subsequently to the error occurrence code. [0144] Upon the reception of the output signal from the threshold value comparison-error bit information notification circuit 403 , the selector 404 selects the output signal from the threshold value comparison-error bit information notification circuit 403 . Accordingly, if the error occurrence code and the error bit information E are received from the threshold value comparison-error bit information notification circuit 403 , the selector 404 supplies the error occurrence code and the error bit information E to the driver 126 . [0145] In addition, when the selector 404 receives the switching completion notification from the error detection-switching circuit 124 , the selector 404 supplies the switching completion notification to the driver 126 . [0146] FIG. 5 is a flowchart illustrating the outline of a process of switching to the spare line according to an embodiment. [0147] Referring to FIG. 5 , for example, when the transmission LSI 110 and the reception LSI 120 are turned on, at S 501 , the transmission LSI 110 and the reception LSI 120 normally start the data transfer process between them. [0148] At S 502 , when the reception LSI 120 detects the number of error occurrences larger than or equal to the line switching threshold value at a bit of the data transmitted from the transmission LSI 110 , the reception LSI 120 generates the error bit information E. [0149] At S 503 , the reception LSI 120 notifies the transmission LSI 110 of the error bit information E. [0150] At S 504 , when the transmission LSI 110 receives the error bit information E from the reception LSI 120 , the transmission LSI 110 switches an error bit line to the spare line. The error bit line indicates the data line where an error has occurred. [0151] When the switching to the spare line is completed, at S 506 , the transmission LSI 110 and the reception LSI 120 restart the data transfer process between them. [0152] FIG. 6 is a flowchart illustrating an example of a process of switching to the spare line in the reception LSI 120 according to an embodiment. [0153] Referring to FIG. 6 , at S 601 , when the transmission LSI 110 and the reception LSI 120 are turned on, the transmission LSI 110 and the reception LSI 120 normally start the data transfer process between them. [0154] At S 602 , the error detection-switching circuit 124 receives the data D from the transmission LSI 110 through the data lines 0 , 1 , . . . , N. Upon the reception of the data D transmitted from the transmission LSI 110 through the data lines 0 , 1 , . . . , N, the error detection-switching circuit 124 performs the error checking process on the data D to determine whether an error occurs on the data D. [0155] At substantially the same time, the error detection-switching circuit 124 transmits the data D to the other LSI or the like connected to the reception LSI 120 through the data output lines 0 , 1 , . . . , and N. [0156] If the error detection-switching circuit 124 detects no error (NO at S 602 ), the error detection-switching circuit 124 repeats S 602 . [0157] If the error detection-switching circuit 124 detects an error (YES at S 602 ), the error detection-switching circuit 124 generates the error bit information E in which the bit where the error has occurred is set to “1” and the other bits are set to “0”. The error detection-switching circuit 124 supplies the generated error bit information E to the error bit notification-switching determination circuit 125 . [0158] When the transmission of the error bit information E is completed, the error detection-switching circuit 124 goes to S 603 . [0159] At S 603 , the error bit notification-switching determination circuit 125 identifies the error bit from the received error bit information E. Then, the error bit notification-switching determination circuit 125 counts the number of error occurrences for every bit of the received error bit information E. [0160] For example, the error bit notification-switching determination circuit 125 refers to the number of error occurrences for every bit, stored in the number-of-error-occurrences storage part in the error bit notification-switching determination circuit 125 . The error bit notification-switching determination circuit 125 stores a value given by adding one to the number of error occurrences at the error bit in the number-of-error-occurrences storage part. [0161] At S 604 , the error bit notification-switching determination circuit 125 compares the line switching threshold value with the number of error occurrences in the error bit information E. The line switching threshold value is set for each bit in advance. [0162] If the number of error occurrences is smaller than the line switching threshold value (NO at S 604 ), the error bit notification-switching determination circuit 125 goes back to S 602 . If the number of error occurrences is larger than or equal to the line switching threshold value (YES at S 604 ), the error bit notification-switching determination circuit 125 goes to S 605 . [0163] At S 605 , the error bit notification-switching determination circuit 125 generates the error occurrence code, which is set in advance. Then, the error bit notification-switching determination circuit 125 transmits the error occurrence code and the error bit information E to the transmission LSI 110 through the error-bit information line. [0164] The error-bit information line according to an embodiment is a line thorough which one-bit-width data is transmitted. Accordingly, the error bit notification-switching determination circuit 125 encodes the error bit information E into serial data and supplies the encoded error bit information E to the driver 126 , subsequently to the error occurrence code. [0165] However, the error-bit information line is not limited to the line through which one-bit-width data is transmitted. For example, the error-bit information line may be a line through which N+1-bit-width data is transmitted. [0166] At S 606 , the error detection-switching circuit 124 determines whether the switching code is received through the spare line. [0167] If the switching code is not received through the spare line (NO at S 606 ), the error detection-switching circuit 124 goes back to S 605 . If the switching code is received through the spare line (YES at S 606 ), the error detection-switching circuit 124 goes to S 607 . [0168] At S 607 , the error detection-switching circuit 124 switches the data line through which the data on the bit identified by the switching bit information received after the switching code is transferred to the spare line. In other words, the error detection-switching circuit 124 receives the data on the bit identified by the switching bit information through the spare line. [0169] When the switching to the spare line is completed at S 607 , then at S 608 , the error detection-switching circuit 124 transmits the switching completion notification to the transmission LSI 110 . [0170] At S 609 , the reception LSI 120 completes the process of switching to the spare line. [0171] FIG. 7 is a flowchart illustrating an example of a process of switching to the spare line in the reception LSI 120 according to an embodiment. Referring to FIG. 7 , for example, when the transmission LSI 110 and the reception LSI 120 are turned on, at S 701 , the transmission LSI 110 and the reception LSI 120 normally start the data transfer process between them. [0172] At S 702 , the selection circuit 111 determines whether the error occurrence code transmitted from the error bit notification-switching determination circuit 125 is received through the error-bit information line. [0173] If the error occurrence code is not received through the error-bit information line (NO at S 702 ), the selection circuit 111 repeats S 702 . If the error occurrence code is received through the error-bit information line (YES at S 702 ), the selection circuit 111 goes to S 703 . [0174] At S 703 , the selection circuit 111 generates the switching code. Then, the selection circuit 111 transmits the generated switching code to the reception LSI 120 through the spare line. [0175] In addition, the selection circuit 111 generates the switching bit information from the error bit information E received after the error occurrence code is received by the selection circuit 111 . Then, the selection circuit 111 transmits the switching bit information to the reception LSI 120 through the spare line, subsequently to the switching code. [0176] After the transmission of the switching code and the switching bit information is completed, at S 704 , the selection circuit 111 transmits the data on the bit position identified in the data D by the switching bit information to the reception LSI 120 through the spare line. [0177] At substantially the same time, the selection circuit 111 transmits the data D to the reception LSI 120 through the data lines 0 , 1 , . . . , and N. [0178] At S 705 , the selection circuit 111 determines whether the switching completion notification transmitted from the error bit notification-switching determination circuit 125 is received through the error-bit information line. [0179] If the selection circuit 111 determines that the switching completion notification is not received through the error-bit information line (NO at S 705 ), the selection circuit 111 goes back to S 703 . If the selection circuit 111 determines that the switching completion notification is received through the error-bit information line (YES at S 705 ), the selection circuit 111 goes to S 706 . At S 706 , the transmission LSI 110 completes the process of switching to the spare line. [0180] FIG. 8 is a time chart of the main signals when the number of error occurrences of transmission data D[ 0 ] transmitted from the transmission LSI 110 to the reception LSI 120 exceeds the line switching threshold value. [0181] The signals transferred through the spare line, the data line 0 , the data lines 1 to N, and the error-bit information line are illustrated in FIG. 8 . [0182] (1) If an error occurs in the data D[ 0 ] received through the data line 0 , the error detection-switching circuit 124 detects the error in the data D[ 0 ]. The error detection-switching circuit 124 detects that the number of error occurrences at the bit 0 exceeds the threshold value. [0183] (2) The error detection-switching circuit 124 transmits the error occurrence code and the error bit information E to the transmission LSI 110 through the error-bit information line. [0184] (3) Upon the reception of the error occurrence code and the error bit information E, the selection circuit 111 switches the line of data D[ 0 ] at the bit 0 identified by the error bit information E to the spare line. Then, the selection circuit 111 transmits the switching code and the switching bit information to the reception LSI 120 through the spare line. [0185] (4) Upon the reception of the switching code and the switching bit information through the spare line, the error detection-switching circuit 124 receives the data D[ 0 ] at the bit 0 identified by the switching bit information through the spare line. The error bit notification-switching determination circuit 125 transmits the switching completion notification to the transmission LSI 110 through the error-bit information line. [0186] Only one spare line is used in the data transfer method described above for simplicity. However, the data transfer method is not limited to the use of only one spare line. [0187] FIG. 9 illustrates a modification of the configuration realizing the data transfer method according to an embodiment. [0188] Referring to FIG. 9 , a data transfer system 900 includes a transmission LSI 910 and a reception LSI 920 . The transmission LSI 910 is connected to the reception LSI 920 so as to be capable of communicating with the reception LSI 920 via data lines 0 , 1 , . . . , and N, spare lines 0 , 1 , . . . , and M, a clock line, and an error-bit information line. “M” denotes a natural number that is not smaller than one and is not larger than “N”. [0189] The spare lines 0 , 1 , . . . , and M are provided for the spare for the data lines and are used to transmit one-bit-width data, respectively. [0190] The transmission LSI 910 includes a selection circuit 911 , FFs 112 - 0 to 112 -N, drivers 113 - 0 to 113 -N, a driver 114 , a receiver 115 , FFs 116 - 0 to 116 -M, and drivers 117 - 0 to 117 -M. [0191] Part of the output terminal of the selection circuit 911 is connected to the FFs 116 - 0 , 116 - 1 , . . . , and 116 -M. [0192] The output terminals of the FFs 116 - 0 , 116 - 1 , . . . , and 116 -M are connected to the drivers 117 - 0 , 117 - 1 , . . . , and 117 -M, respectively. [0193] The output terminals of the drivers 117 - 0 , 117 - 1 , . . . , and 117 -M are connected to the spare lines 0 , 1 , . . . , and M, respectively. [0194] The connection relationship between the other components is a similar to the one in the transmission LSI 110 illustrated in FIG. 1 . [0195] The reception LSI 920 includes receivers 121 - 0 to 121 -N, FFs 122 - 0 to 122 -N, a receiver 123 , an error detection-switching circuit 921 , an error bit notification-switching determination circuit 922 , a driver 126 , receivers 127 - 0 to 127 -M, and FFs 128 - 0 to 128 -M. [0196] The receivers 127 - 0 , 127 - 1 , . . . , and 127 -M are connected to the spare lines 0 , 1 , . . . , and M, respectively. [0197] The output terminals of the receivers 127 - 0 , 127 - 1 , . . . , and 127 -M are connected to the FFs 128 - 0 , 128 - 1 , . . . , and 128 -M, respectively. [0198] The output terminals of the FFs 128 - 0 , 128 - 1 , . . . , and 128 -M are connected to the error detection-switching circuit 921 . [0199] The connection relationship between the other components is a similar to the one in the reception LSI 120 illustrated in FIG. 1 . [0200] In the above configuration, the transmission LSI 910 and the reception LSI 920 performs a process similar to the data transfer process illustrated in FIG. 1 . [0201] The error detection-switching circuit 921 determines whether an error occurs or occurred in the N+1-bit data D composed of the one-bit-width data D[ 0 ] to D[N]. If no error is detected, the error detection-switching circuit 921 outputs the data D of each bit to the data output lines 0 , 1 , . . . , and N. [0202] If an error is detected, the error detection-switching circuit 921 generates the error bit information E and notifies the error bit notification-switching determination circuit 922 of the error bit information E. [0203] Upon the reception of the notification of the error bit information E from the error detection-switching circuit 921 , the error bit notification-switching determination circuit 922 counts the number of error occurrences at the error bit. For example, if an error has occurred in the data D[i], the error bit notification-switching determination circuit 922 counts and stores the number of error occurrences at the bit i. [0204] If the number of error occurrences at the error bit i is larger than or equal to a predetermined value, the error bit notification-switching determination circuit 922 encodes the error bit information E into serial data and supplies the encoded error bit information E to the driver 126 . [0205] The driver 126 transmits the error bit information E to the receiver 115 through the error-bit information line. The receiver 115 supplies the error bit information E transmitted from the driver 126 to the selection circuit 911 . [0206] Upon the reception of the error bit information E from the receiver 115 , the selection circuit 911 decodes the error bit information E in the serial data to identify the error bit i. Then, the selection circuit 911 switches the destination of the data D[i] at the error bit i from the FF 112 - i to any of the FFs 116 - 0 , 116 - 1 , . . . , and 116 -M. The FF that is set as the destination of the data D[i] is denoted by an FF 116 - j , where “j” is a natural number that includes zero and is not larger than “M”. The same applies to the driver 117 , the spare line, the receiver 127 , the FF 128 , the switching-signal selection circuit 202 , and the selector 204 in the following description. [0207] Here, the selection circuit 911 selects one of the FFs 116 - 0 , 116 - 1 , . . . , and 116 -M, for example, in accordance with an predetermined order and outputs the data D[i] to the selected FF. In this case, the FFs that have been selected and used are excluded from the selection candidate. [0208] At substantially the same time, the selection circuit 911 generates the switching bit information and supplies the switching bit information to the FF 116 - j. [0209] Then, the selection circuit 911 supplies the data D[ 0 ], D[ 1 ], . . . , and D[N] received from another LSI or the like to the FFs 112 - 0 , 112 - 1 , . . . , and 112 -N, respectively. However, the selection circuit 911 supplies only the data D[i] to the FF 116 - j. [0210] The FF 116 - j holds the switching bit information supplied from the selection circuit 911 . The FF 116 - j supplies the switching bit information to the driver 117 - j in synchronization with the clock signal CLK. The driver 117 - j transmits the switching bit information to the receiver 127 - j through the spare line j. [0211] Upon the reception of the switching bit information from the driver 117 - j , the receiver 127 - j supplies the switching bit information to the FF 128 - j . The FF 128 - j holds the switching bit information. The FF 128 - j supplies the switching bit information to the error detection-switching circuit 921 in synchronization with the clock signal CLK supplied from the receiver 123 . [0212] The data D[i] is transmitted from the selection circuit 911 to the error detection-switching circuit 921 in a process similar to that for the switching bit information. The data D excluding the data D[i] is transferred in the manner described above. [0213] Upon the reception of the switching bit information from the FF 128 - j , the error detection-switching circuit 921 switches the data line i through which the data D[i] at the bit i identified by the switching bit information is transferred to the spare line j. Then, the error detection-switching circuit 921 supplies the switching completion notification to the error bit notification-switching determination circuit 922 . [0214] The error bit notification-switching determination circuit 922 supplies the received switching completion notification to the driver 126 . The driver 126 transmits the switching completion notification to the receiver 115 through the error-bit information line. [0215] FIG. 10 illustrates a specific example of the configuration of the selection circuit 911 when a plurality of spare lines is used. [0216] The selection circuit 911 includes a switching-bit specifying circuit 1001 , switching-signal selection circuits 202 - 0 , 202 - 1 , . . . , and 202 -M, a switching code-switching bit information generation circuit 1002 , and selectors 204 - 0 , 204 - 1 , . . . , and 204 -M. [0217] The switching-signal selection circuits 202 - 0 , 202 - 1 , . . . , and 202 -M each include AND circuits 202 a - 0 , 202 a - 1 , . . . , and 202 a -N and an OR circuit 202 b. [0218] The switching-bit specifying circuit 1001 , the switching-signal selection circuit 202 - 0 , the switching code-switching bit information generation circuit 1002 , and the selector 204 - 0 have substantially the same configuration as that of the switching-bit specifying circuit 201 , the switching-signal selection circuit 202 , the switching code-switching bit information generation circuit 203 , and the selector 204 as illustrated in FIG. 2 . In this case, a switching-bit specifying line group 0 is composed of the switching bit specifying lines 0 to N as illustrated in FIG. 2 . [0219] The same applies to the remaining switching-signal selection circuits 202 - 1 , 202 - 2 , . . . , and 202 -M. [0220] For example, the switching-bit specifying circuit 1001 , the switching-signal selection circuit 202 -M, the switching code-switching bit information generation circuit 1002 , and the selector 204 -M have substantially the same configuration as that of the switching-bit specifying circuit 201 , the switching-signal selection circuit 202 , the switching code-switching bit information generation circuit 203 , and the selector 204 as illustrated in FIG. 2 . In this case, a switching-bit specifying line group M is composed of the switching bit specifying lines 0 to N as illustrated in FIG. 2 . [0221] In the above configuration, when the switching-bit specifying circuit 1001 detects the error occurrence code, the switching-bit specifying circuit 1001 receives the error bit information E from the receiver 115 transmitted from the error bit notification-switching determination circuit 922 after the error occurrence code is transmitted. [0222] Then, the switching-bit specifying circuit 1001 decodes the error bit information E transmitted as the serial data to identify the error bit. The switching-bit specifying circuit 1001 generates the switching-bit specifying data S. [0223] The switching-bit specifying circuit 1001 selects the switching-signal selection circuit 202 - j to which the switching-bit specifying data S is to be supplied from the switching-signal selection circuits 202 - 0 to 202 -M in accordance with an predetermined order. The switching-bit specifying circuit 1001 supplies the switching-bit specifying data S to the selected switching-signal selection circuit 202 - j. [0224] The operation of the switching-signal selection circuit 202 - j and the selector 204 - j is substantially the same as that of the switching-signal selection circuit 202 and the selector 204 described above with reference to FIG. 2 . [0225] When the switching code-switching bit information generation circuit 1002 detects the error occurrence code, the switching code-switching bit information generation circuit 1002 receives the error bit information E which is transmitted from the error bit notification-switching determination circuit 922 after the error occurrence code, from the receiver 115 . [0226] Then, the switching code-switching bit information generation circuit 1002 decodes the error bit information E transmitted as the serial data to identify the error bit. The switching code-switching bit information generation circuit 1002 generates the switching bit information. [0227] The switching code-switching bit information generation circuit 1002 selects the selector 204 - j to which the switching bit information is to be supplied from the selectors 204 - 0 to 204 -M in accordance with a predetermined order. [0228] The switching code-switching bit information generation circuit 1002 generates the switching code and encodes the switching bit information into serial data. The switching code-switching bit information generation circuit 1002 supplies the switching code and the switching bit information to the selector 204 - j . Here, the switching code-switching bit information generation circuit 1002 outputs the switching bit information after the switching code. [0229] When the output signal is received from the switching code-switching bit information generation circuit 1002 , the selector 204 - j selects the output signal from the switching code-switching bit information generation circuit 1002 and supplies the selected output signal to the FF 116 - j . When no output signal is received from the switching code-switching bit information generation circuit 1002 , the selector 204 - j supplies the output signal from the OR circuit 202 b in the switching-signal selection circuit 202 - j to the FF 116 - j. [0230] FIG. 11 illustrates a specific example of the configuration of the error detection-switching circuit 921 when a plurality of spare lines is used. [0231] The error detection-switching circuit 921 includes selectors 1101 - 0 to 1101 -N, an error detection-correction circuit 1102 , a switching-timing generation circuit 1103 , and OR circuits 304 - 0 to 304 -M. [0232] The output terminals of the FFs 122 - 0 , 122 - 1 , . . . , and 122 -N are connected to the selectors 1101 - 0 , 1101 - 2 , . . . , and 1101 -N, respectively. [0233] The output terminal of the FF 128 - 0 is connected to the selectors 1101 - 0 , 1101 - 1 , . . . , and 1101 -N and the switching-timing generation circuit 1103 . The output terminals of the FFs 128 - 1 , 128 - 2 , . . . , and 128 -M are also connected to the selectors 1101 - 0 , 1101 - 1 , . . . , and 1101 -N and the switching-timing generation circuit 1103 . [0234] The output terminal of the switching-timing generation circuit 1103 is connected to the OR circuits 304 - 0 , 304 - 1 , . . . , and 304 -M. The output terminals of the switching-timing generation circuit 1103 , connected to the OR circuits 304 - 0 , 304 - 1 , . . . , and 304 -M, are connected to the selectors 1101 - 0 , 1101 - 1 , . . . , and 1101 -N, respectively. [0235] For example, the output terminal of the switching-timing generation circuit 1103 connected to the OR circuit 304 - 0 also connects to the selectors 1101 - 0 , 1101 - 1 , . . . , and 1101 -N. Here, one-bit-width data is transmitted through the lines connecting the switching-timing generation circuit 1103 to the selectors 1101 - 0 , 1101 - 1 , . . . , and 1101 -N. [0236] The output terminals of the selectors 1101 - 0 , 1101 - 1 , . . . , and 1101 -N are connected to the error detection-correction circuit 1102 . [0237] Among the output terminals of the error detection-correction circuit 1102 , the output terminals through which the data D is outputted connects to the data output lines 0 , 1 , . . . and N connected to the other LSI or the like (not illustrated). Among the output terminals of the error detection-correction circuit 1102 , the error-bit information line through which the error bit information E is outputted connects to the error bit notification-switching determination circuit 922 . [0238] The output terminals of the OR circuit 304 - 0 , 304 - 1 , . . . , and 304 -M are connected to the error bit notification-switching determination circuit 922 . [0239] In the above configuration, for example, the selector 1101 - 0 selects the output signal from the FF 128 - j if the switching instruction data Ij[ 0 ], among the switching instruction data I 0 [ 0 ], I 1 [ 0 ], . . . , and IM[ 0 ] output from the switching-timing generation circuit 1103 which is set to “1”. The selector 1101 - 0 selects the output signal from the FF 122 - 0 if the switching instruction data I 0 [ 0 ], I 1 [ 0 ], . . . , and IM[ 0 ] are set to “0”, respectively. The selector 1101 - 0 supplies the selected signal to the error detection-correction circuit 1102 . [0240] The remaining selectors 1101 - 1 , 1101 - 2 , . . . , and 1101 -N perform similar operations. For example, the selector 1101 -N selects the output signal from the FF 128 - j if the switching instruction data Ij[N] among the switching instruction data I 0 [N], I 1 [N], . . . , and IM[N] output from the switching-timing generation circuit 1103 is set to “1”. The selector 1101 -N selects the output signal from the FF 122 -N if the switching instruction data I 0 [N], I 1 [N], . . . , and IM[N] are set to “0”, respectively. The selector 1101 -N supplies the selected signal to the error detection-correction circuit 1102 . [0241] The error detection-correction circuit 1102 receives the data D[ 0 ], D[ 1 ], . . . , and D[N] supplied from the selectors 1101 - 0 , 1101 - 1 , . . . , and 101 -N, respectively. The error detection-correction circuit 1102 performs the error checking process on the N+1-bit-width data D composed of the data D[ 0 ], D[ 1 ], . . . , and D[N]. [0242] If no error is detected, the error detection-correction circuit 1102 supplies the data D of each bit to the data output lines 0 , 1 , . . . , and N. If an error is detected, the error detection-correction circuit 1102 generates the error bit information E. [0243] After generating the error bit information E, the error detection-correction circuit 1102 supplies the error bit information E to the error bit notification-switching determination circuit 922 . [0244] If the switching-timing generation circuit 1103 detects the switching code from the output signal from the FF 128 - 0 , the switching-timing generation circuit 1103 acquires the switching bit information transmitted after the switching code. Then, the switching-timing generation circuit 1103 generates the switching instruction data I 0 . The switching instruction data I 0 is similar to the switching instruction data I described above with reference to FIG. 3 . [0245] After generating the switching instruction data I 0 , the switching-timing generation circuit 1103 supplies the switching instruction data I 0 of each bit to the selectors 1101 - 0 , 1101 - 1 , . . . , and 1101 -N. For example, the switching-timing generation circuit 1103 supplies the switching instruction data I 0 [ 0 ] to the selector 1101 - 0 . Similarly, the switching-timing generation circuit 1103 supplies the switching instruction data I 0 [N] to the selector 1101 -N, respectively. [0246] The switching-timing generation circuit 1103 generates the switching instruction data I 1 , . . . , and IM in a similar process. Then, the switching-timing generation circuit 1103 supplies the switching instruction data I 1 , . . . , and IM of each bit to the selectors 1101 - 0 , 1101 - 1 , . . . , and 1101 -N, respectively. [0247] In addition, the switching-timing generation circuit 1103 supplies the switching instruction data I 0 , the switching instruction data I 1 , . . . , and the switching instruction data IM to the OR circuits 304 - 0 , 304 - 1 , . . . , and 304 -M, respectively. [0248] For example, the OR circuit 304 - 0 supplies a result of the logical OR operation of the data I 0 [ 0 ], I 0 [ 1 ], . . . , and I 0 [N] composing the switching instruction data I 0 to the error bit notification-switching determination circuit 922 . Similarly, the OR circuit 304 -M supplies a result of the logical OR operation of the data IM[ 0 ], IM[ 1 ], . . . , and IM[N] composing the switching instruction data IM to the error bit notification-switching determination circuit 922 . [0249] A result of the logical OR operation output from the OR circuits 304 - 0 , 304 - 1 , . . . , and 304 -M is used as a signal of a “switching completion notification”. [0250] Since the error bit notification-switching determination circuit 922 has a configuration similar to that of the error bit notification-switching determination circuit 125 illustrated in FIG. 4 , a detailed description of the error bit notification-switching determination circuit 922 is omitted herein. However, the output terminals of the OR circuits 304 - 0 , 304 - 1 , . . . , and 304 -M in the error detection-switching circuit 921 are connected to the selector 404 . Upon the reception of the output signals from the OR circuits 304 - 0 , 304 - 1 , . . . , and 304 -M, the selector 404 selects one of the received output signals and supplies the selected output signal to the driver 126 . [0251] As described above, the data transfer system 100 includes the spare line, in addition to the data lines 0 , 1 , . . . , and N, the clock line, and the error-bit information line. [0252] The reception LSI 120 counts the number of error occurrences in the received data D for every bit. The reception LSI 120 notifies the transmission LSI 110 of the error bit information if the number of error occurrences is larger than or equal to the line switching threshold value. The transmission LSI 110 switches the destination of the data on the error bit identified by the received error bit information to the spare line. [0253] As a result, for example, even if a fixed error occurs in one of the data lines or errors frequently occur, it is possible to recover to the normal data transfer process. [0254] One-bit-width data is transmitted through the spare line in the data transfer system 100 , and only one spare line is provided in the data transfer system 100 . Accordingly, the redundant signal wiring can be minimized. In addition, an increase in the manufacturing cost may be suppressed. [0255] As described above, with the data transfer system 100 , it is possible to improve the reliability of the data transfer process with minimized redundant signal wiring. [0256] The data transfer system 900 includes the spare lines 0 , 1 , . . . , and M, in addition to the data lines 0 , 1 , . . . , and N, the clock line, and the error-bit information line. [0257] The reception LSI 920 counts the number of error occurrences in the received data D for every bit. The reception LSI 920 notifies the transmission LSI 910 of the error bit information if the number of error occurrences is larger than or equal to the line switching threshold value. The transmission LSI 910 selects the spare line j from the spare lines 0 , 1 , . . . , and M and switches the destination of the data on the error bit identified by the received error bit information to the spare line j. [0258] As a result, advantages similar to those in the data transfer system 100 are offered. [0259] Furthermore, since the data transfer system 900 include the M-number spare lines, it is possible to recover to the normal transfer process even if fixed errors occur in two or more lines in the data lines. [0260] All examples and conditional language recited herein are intended for pedagogical objects to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Although the embodiment(s) of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

A data transfer system transmitting and receiving data through a first transmission path and a second transmission path, the data transferring system includes a first apparatus that transmits data through the first transmission path and a second apparatus that receives the data from the first apparatus through the first transmission path, the second apparatus transmits error bit information about the bit position of an error, wherein when the first apparatus receives the error bit information from the second apparatus, the first apparatus transmits switching bit information concerning the bit position which is identified by the error bit information and the transmission path of which is switched to the second transmission path and the data on the bit position identified by the error bit information to the second apparatus through the second transmission path, and the second apparatus receives the data on the bit position identified by the switching bit information.

CROSS-REFERENCE TO RELATED APPLICATION [0001] The present invention is a CIP application of U.S. patent application Ser. No. 13/146,106 filed on Oct. 10, 2011. This application claims priorities from Korea Patent Application No. 10-2009-0008745 filed on Feb. 4, 2009 and PCT Patent Application No. PCT/KR2010/000665 filed on Feb. 3, 2010, all of which are incorporated herein by reference in its entirety. TECHNICAL FIELD [0002] The present invention relates to a system and a method for automatically collecting opinions. More particular, the present invention relates to a system and a method for automatically collecting opinions by compiling statistics with users' opinions collected through voting, public opinion polls, surveys, and other feedback and providing the user opinions. BACKGROUND ART [0003] When an election/voting process and a public opinion poll are largely divided, the election part includes organizing information of a candidate running for a particular election, promoting and opening to election participants, managing voters, drawing and managing voting results, and the voting participant demands for accurate and prompt information about the candidate from an election administrator and to guarantee an unrestricted voter environment. Meanwhile, the public opinion poll is largely divided into determining and suggesting question items in a field to survey, determining and suggesting response items for each question item, selecting responses of respondents, and compiling and managing statistics with the survey results. [0004] In most of current election votes, the information of the candidate is opened mainly using a poster of a paper medium or a banner, and a representative election voting is an analogue voting where the voter attends a certain place within a certain time period and casts a vote in person. [0005] As such, the current representative voting method not only takes considerable expenses economically but also increases an abstention rate according to physical movement of the voter who is under physical limitation, and thus the election voting method needs to be enhanced. [0006] Meanwhile, a representative opinion survey for a specific purpose is a public opinion poll. Since the current public opinion polling method mainly performs a method for responding to a questionnaire made of paper, a survey method according to question and answer over the phone, or an approach via a polling service provider, the physical limitation on the questioner and the respondent is great and a service technique manageable directly by users including the manager is not developed. [0007] Korean Patent Publication No. 2005-0102046 (ELECTRONIC VOTING AND ELECTION SYSTEM) is an electronic voting system which includes a voter ID confirmation terminal for identifying a voter by searching an integrated voter register DB or a unit voter register DB connected through a network, and storing voting to the integrated voter register DB or the unit voter register DB in real-time when the identification of the voter and the duplicated voting are successfully checked by the ID confirmation means, an electronic voting ticket issuer for issuing an electronic voting ticket capable of displaying election and election district information, and an images of a relevant election district and candidate combination and erasing the stored information after completing the voting, and an electronic voting machine operated in an offline method independent of the integrated voter register confirmation DB, guiding the voter in a voting procedure when the voter inserts the electronic voting ticket, and storing a voting result of the voter. The electronic voting machine includes a candidate information storing medium for storing the image of the candidate combination registered to all of the voting districts of the nation, a display device for displaying the image of the candidate combination of the district of the voter stored to the candidate information storing medium based on the information stored to the electronic voting card, an input device for selecting one of the candidates displayed in the display device, a voting result storage device for storing the voting result, and an output device for printing and outputting the voting result to a voting recording paper. [0008] Korean Patent Publication No. 10-2005-0102051 (ELECTRONIC VOTING SYSTEM USING INTERNET) is an electronic voting system including a candidate information storage device which stores an image of a candidate group registered to an election district, an integrated voter register DB which stores voter information integrated in a national or regional unit, a certification center which performs identification of the voter who uses a terminal connected through the Internet through electronic authentication based on the voter information, and a web server which provides the voter certified by the certification center with a candidate selection web screen including the image of the candidate group, and transmits the voting result through the web screen, as an election management system for counting and collecting an election result per election or per election district. [0009] Korean Patent Publication No. 10-2005-0001975 (ELECTRONIC VOTING SYSTEM AND ELECTRONIC VOTING METHOD USING ID-BASED BLIND SIGNATURE) is an electronic voting system using ID-based blind signature, including a certification authority server for inserting the signature into an electronic vote sheet with a voter certification in a state that contents of the received electronic vote sheet are unknown according to an ID-based blind signature method and transmitting it to a voter terminal; a collection server for verifying the vote by collecting the electronic vote sheet containing the signature during a vote time; and a voter terminal for transmitting the vote sheet blinding and encrypting vote contents by using the ID-based blind signature to the certification authority server, and encrypting and transmitting the vote sheet to the collection server without blinding the vote sheet when the electronic vote sheet containing the signature is received from the certification authority server. [0010] Korean Patent Publication No. 10-2008-0040932 (DEVICE AND METHOD OF E-VOTING USING MOBILE TERMINAL) is an e-voting device including a voter ID checker which authenticates a voter based on a certificate received from a mobile terminal of the voter through a mobile network; an encoding key manager which generates and transmits an encoding key for encoding voting contents to the mobile terminal; a voting information provider which transmits voting information including election candidates to the mobile terminal; and a voting result storing part which decodes and stores the encoded voting contents of which ID information of the voter is removed from the encoded voting contents including voting result information of the voter based on the voting information. [0011] Korean Patent Publication No. 10-2008-0099165 (ELECTION MANAGEMENT METHOD AND ELECTION MANAGEMENT SERVER IN NETWORK USING PERSONAL TERMINAL) is an election management method in a network using a personal terminal, including the steps of storing, at an election managing server, identification information of each voter required for wired/wireless communication with each voter; sending, at the election managing server, certain URL information to voter terminals used by the voters through the identification information of each voter; receiving, at the election managing server, voting information from the voter terminal connected to the certain URL; generating, at the election managing server, a first password code by inputting the voting information and the identification information of the voter received from the voter terminal into a first function; generating, at the election managing server, a second password code by inputting the first password code to a second function; and storing the generated second password code together with the voting information. [0012] Korean Patent Publication No. 10-2008-0007949 (SYSTEM FOR FURNISHING ELECTION POSTER IN ON-LINE AND METHOD THEREOF) is an on-line election poster furnishing system including a central election manager server which computerizes and stores candidate information and election posters including a candidate name, an election type, an election area, academic records, careers, and election pledges of each election candidate submitted to an election management agent, to a database, stores election information including an election schedule, a polling place, a voting procedure, and election related news to the database, and selectively provides the information stored in the database to a cyber election poster management server; and the cyber election poster management server which provides a site for providing the candidate information and the election information, and searches for and provides the candidate information and the election poster of a particular candidate by accessing to the central election management server according to a request of a user terminal. [0013] Korean Patent Publication No. 10-2003-0056259 (METHOD AND SYSTEM OF PERFORMING AN ELECTION CAMPAIGN BASED ON INFORMATION USING WIRED/WIRELESS COMMUNICATION NETWORKS) is a method for performing an election campaign based on information of voters using wired/wireless communication networks. The election campaign method based on the voter information using the communication network includes storing the voter information, storing candidate PR information which is contents provided to the voter from the candidate, generating and storing an information provision voter selection code per item for searching the voter to transmit the item according to the candidate PR information item, storing a forwarding condition to forward the candidate PR information, and searching for the voter to receive the PR information item matched with the information provision voter selection code when the forwarding condition is satisfied, and forwarding the PR information to the searched voter. [0014] Korean Patent Publication No. 10-2002-0055734 (METHOD AND SYSTEM FOR EXIT POLL BY USING MOBILE TELECOMMUNICATION DEVICES) is an exit poll method using a mobile telecommunication device which includes a position information service center for locating a user, an election exit poll server for performing the election exit poll based on the position information of the user, and a short message service center for processing a short message for the election exit poll. The exit poll method using the mobile telecommunication devices includes receiving position information of a user according to voting areas from a position information service center; creating a short message for the election exit poll according to corresponding voting area based on the position information of the user transmitted per voting area and transmitting the short message to the short message service center; transmitting the transmitted short message to a wireless modem or a wireless communication device of a corresponding user using a wireless data network; transmitting user response data with respect to the short message to the election exit poll server; and creating an elected candidate state according to voting areas of the user based on the transmitted response data. [0015] Korean Patent Publication No. 2001-0103820 (PUBLIC-OPINION POLL USING WAP-BASED WIRELESS INTERNET TERMINAL) is a method for joining a plurality of subscribers having a WAP-based wireless Internet terminal and subscribed as a public opinion poll member, to members. The system and the method conduct the public-opinion pull using all of media including sound, picture, character, and video reproduced by the terminal by including the subscription via the wired Internet including a home page operated by a public-opinion poll agency together with the direct subscription over the wireless Internet using the terminal. [0016] Korean Patent Publication No. 2002-0078813 (METHOD FOR SEARCHING PUBLIC OPINION USING MOBILE TERMINAL) is a method for surveying public opinion using a mobile terminal, including storing, at a certain requester of the public opinion survey, data of a wanted public opinion survey to a web server, extracting, at a mobile communication company, a group adapted to the survey, requesting mobile terminals of the extracted group to respond to the survey, connecting, at the mobile terminal user, to the web server using a web browser stored in the mobile terminal and responding to the survey, and supplying, at the mobile communication company, a predetermined commission to a charged account of the terminal user who responded to the survey. [0017] Korean Patent Publication No. 2006-0095215 (ELECTRONIC VOTING SYSTEM USING MOBILE COMMUNICATION TERMINAL AND METHOD THEREOF) is an electronic voting system using a mobile communication terminal, including a plurality of voter terminals which receive and display a voting case short message, and generate and send voting response short messages when voting responses are received from voters, an add-up terminal which transmits the voting case short message for a voting case to the voters who will participate in voting, and receives the voting response short messages from the voters to add up and count voting results, and a short message service center which provides a short message transmission and reception service between the voter terminals and the add-up terminal. [0018] Korean Patent Publication No. 2006-0068884 (METHOD AND SYSTEM FOR PUBLIC OPINION SURVEY SERVICE USING MOBILE COMMUNICATION NETWORK) is a public opinion survey service using a mobile communication network, including checking whether a mobile communication service subscriber participates in the public opinion survey and receiving a result through a mobile communication terminal, storing users agreeing to the participation in the public opinion survey, extracting a response panel sample of an intended public opinion survey from the stored users agreeing to the participation in the public opinion survey, storing the extracted response panel sample, requesting to respond to the public opinion survey through mobile communication terminals of a response panel corresponding to the stored response panel sample using a mobile communication network, transmitting public opinion survey questions to the mobile communication terminals of the response panel agreeing to the public opinion survey response request, receiving responses for the public opinion survey from the mobile communication terminal, and storing the received responses of the response panel. [0019] Korean Patent Publication No. 2006-0098671 (CYBER PUBLIC OPINION RESEARCH SYSTEM AND METHOD) is a cyber public opinion research system for searching and collecting writings including a preset keyword by accessing to other sites of Internet network. The cyber public opinion research system includes a web server for approving as a member by receiving member information from a client who wants to request the public opinion research, receiving and storing a keyword for the public opinion research to a data collection server, displaying the collected and stored writings to check a valuation per level according to preference or non-preference, and applying a preset weight to the writings evaluated per level and calculating a public opinion index by considering hits; the data collection server for collecting questions and replies including the corresponding keyword without overlap by connecting to a knowledge search webpage of a portal site with the registered keyword, storing the writings per item (data source, written when, written by, hits, contents (question/reply)), and storing contents by classifying the contents into the question and the reply; and a search server for outputting the same result as the search for all portal sites by searching and inquiring the data stored to the data collection server. [0020] Korean Patent Publication No. 2007-0046314 (SYSTEM FOR PERFORMING PUBLIC-OPINION POLL USING MOBILE COMMUNICATION NETWORK AND METHOD THEREOF) is a public-opinion poll system using a mobile communication network and Internet. The public-opinion poll system using the mobile communication network includes a mobile terminal including a camera and transmitting a subscriber face image pre-captured by the camera, a web server for transmitting a public-opinion poll participation message to the mobile communication terminal by accessing the mobile communication network and the Internet, transmitting the public-opinion poll question message only to the terminal responding to the public-opinion poll participation message in the mobile communication terminal, and then receiving the captured subscriber face image data from the mobile communication terminal, and a public-opinion poll server for checking blink time and counts in the subscriber face image data received from the mobile communication terminal, converting a checking result into response data of the public opinion poll, and generating public-opinion poll result data by analyzing the response data of the collected public opinions. [0021] Current methods of collecting public opinions involve having an opinion collecting server, which is connected to various opinion inputting terminals through a network. Here, a spread sheet is used as its file system. Collecting and storing user opinions and analyzing statistics of the collected user opinions are performed with the spread sheet. Therefore, survey results are provided to users only. FIG. 23 is a diagram of a system for automatically collecting opinions based on a spread sheet as its file system. However, this spread sheet-based opinion collecting system has a drawback in that this is a closed system, in which any information or data related to the survey cannot be shared with other users. Therefore, there is a need to have a system, in which information or data related to the survey can be shared with other users and monitored in real time. DETAILED DESCRIPTION OF THE INVENTION Technical Object of the Invention [0022] To address the above-discussed deficiencies, an aspect of the present invention is to a system and a method for automatically collecting opinions such that a manager (or a user) in person can automatically collect user opinions required for voting, public opinion polls, surveys, and other feedback on line through PCs or portable communication equipment with an easy user interface and automatically compile statistics with the collected user opinions. [0023] In addition, another aspect of the present invention is to a system and a method for automatically collecting opinions based on web with functions allowing a manager (or a user) to directly manage related information and procedure and to search for related information. Construction and Operation of the Invention [0024] According to one aspect of the present invention, a method for automatically collecting opinions includes generating a metadata frame comprising metadata items required for an opinion collecting service; generating contents comprising actual metadata corresponding to metadata items contained in the metadata frame; distributing the contents to a user terminal; receiving the reply contents from the user terminal in response to the contents; extracting user's opinion contained in the reply contents and compiling statistics; and providing a result of the statistics compiling. [0025] The opinion collecting service may include at least one of a service for collecting a voting result and a service for collecting opinion, and may be selectable by a manager. [0026] The method may further include authenticating whether a rightful manager accesses a server which performs the opinion collecting service, and the metadata frame generating step may be performed when the authenticating step confirms that the rightful manager accesses. [0027] The authentication may be performed using at least one of 1) ID/PW check, 2) authentication using a certificate or a digital signature, 3) verification using an authentication card and/or a USB memory, and 4) identification using biometric information, and the biometric information may include at least one of a photo, voice, a fingerprint, and an iris. [0028] The biometric information may be obtained through a device equipped or connected to a server which conducts the opinion collecting service. [0029] The contents may include at least one of contents comprising information to refer to before opinion decision, and contents used to input the determined opining after the opinion decision. [0030] The opinion collecting service may be a service for collecting a voting result, the contents comprising the information to refer to before the opinion decision may be contents comprising information relating to a candidate, and the contents used to input the determined opining after the opinion decision may be contents which function as a ballot paper. [0031] The opinion collecting service may be a service for collecting opinion, the contents comprising the information to refer to before the opinion decision may be contents comprising a question, and the contents used to input the determined opining after the opinion decision may be contents which function as a response collecting paper. The question may include at least one of a multiple-choice question and a short-answer question. The distributing step may selectively distribute the contents only to users which are opinion collecting targets. [0032] The distributing step may distribute the contents with at least one of a mobile phone number, an IP address, and an E-mail address of the users of the opinion collecting target. [0033] The method may further include storing the reply contents received in the receiving step. [0034] The method may further include outputting a count state of the reply contents in real time. [0035] The metadata frame generating step may further include extracting metadata items required for an automatic opinion collecting service; generating and databasing the extracted metadata items as metadata description frames; extracting necessary metadata description frames from the databased metadata description frames; and generating a metadata frame of a table type by converting the extracted metadata description frames. [0036] The metadata item extracting step may extract the metadata items using according to an ontology scheme. [0037] The databasing step may generate metadata description frames with the extracted metadata items using a description method according to at least one of a data model of Resource Description Framework (RDF), eXtensible Hyper Text Markup Language (XHTML), and eXtensible Markup Language (XML) database, and a spread sheet. [0038] The method may further include generating a metadata description frame by reversely converting a reply metadata frame of the table type contained in the received reply contents, to a metadata description frame, and databasing the generated metadata description frame. [0039] The method may further include searching for intended information in the databased metadata description frames. [0040] According to another aspect of the present invention, a method for automatically inputting opinions includes showing opinion determining contents which contain information to refer to before opinion decision; receiving user opinion from a user using opinion inputting contents used to input the determined opinion after the opinion decision; generating reply contents containing the user opining input in the inputting step; and transmitting the reply contents. [0041] The method may further include receiving the opinion determining contents and the opinion inputting contents from a server which performs an opinion collecting service, and the transmitting step may transmit the reply contents to the server. [0042] The opinion collecting service may include at least one of a service for collecting a voting result and a service for collecting opinion. [0043] The opinion collecting service may be a service for collecting the voting result, the contents comprising the information to refer to before the opinion decision may be contents comprising information relating to a candidate, and the contents used to input the determined opining after the opinion decision may be contents which function as a ballot paper. [0044] The opinion collecting service may be a service for collecting opinion, the contents comprising the information to refer to before the opinion decision may be contents comprising a question, and the contents used to input the determined opining after the opinion decision may be contents which function as a response collecting paper. [0045] The opinion inputting step may convert and show the opinion inputting contents to a user interface through which the user is able to input the opinion while reading, and then receive the user opinion from the user. [0046] The method may further include authenticating whether the user is a rightful user for the opinion decision, and the transmitting step may be performed when the user is verified as the rightful user. [0047] The authentication may be performed using at least one of 1) ID/PW check, 2) authentication using a certificate or a digital signature, 3) verification using an authentication card and/or a USB memory, and 4) identification using biometric information, and the biometric information may include at least one of a photo, voice, a fingerprint, and an iris. [0048] The biometric information may be obtained through a device equipped or connected to a terminal which receives the user opinion. [0049] According to yet another aspect of the present invention, a system for automatically collecting opinions includes an opinion collecting server for generating a metadata frame comprising metadata items required for an opinion collecting service, generating contents comprising actual metadata corresponding to the metadata items contained in the metadata frame, distributing the contents to the user terminal, receiving the reply contents from the user terminal in response to the contents, extracting user's opinion contained in the reply contents and compiling statistics, and providing a result of the statistics compiling; and an opinion inputting terminal for receiving user opinion from a user using the contents received from the opinion collecting server, generating reply contents containing the user opinion, and transmitting the reply contents to the opinion collecting server. [0050] The contents may include at least one of contents comprising information to refer to before opinion decision, and contents used to input the determined opining after the opinion decision. [0051] The opinion collecting server may extract metadata items required for an automatic opinion collecting service, generate and database the extracted metadata items as metadata description frames, extracts necessary metadata description frames from the databased metadata description frames, and generate a metadata frame of a table type by converting the extracted metadata description frames. [0052] The opinion collecting server may generate a metadata description frame by reversely converting a reply metadata frame of the table type contained in the received reply contents, to a metadata description frame, and database the generated metadata description frame. Effect of the Invention [0053] As set forth above, according to the present invention, it is possible to automatically collect on line the user opinions required for the voting, the public opinion poll, the survey, and other feedback through the PC or the portable communication equipment with the easy and convenient user interface, and to automatically compile the statistics with the collected user opinions. In addition, it is easy to store and retrieve the related information. Hence, by utilizing the system of the present invention as the web service, the voters or the researchers can conveniently and easily conduct the voting or the opinion survey activity anytime and anywhere without limitations on the physical place and the time, thus creating economic and social benefits. [0054] Particularly, the manager (or the user) can produce economic and social benefits by automatically conducting the election promotion using the banner and the paper poster candidate promotion materials, the analog election/voting procedure and statistics limited to particular time and place, and the opinion public poll or the opinion survey using the questionnaire or the phone call, and directly using the Internet or the information device such as mobile phone without intervention of a service agent. [0055] In particular, the advantageous effects of the present invention are as follows: It is possible to share all information related to public opinions among users. For example, the database-based opinion collection system of the present invention enables all users to share contents, procedures, and results of all surveys conducted with users. However, the file system-based opinion collection does not provide such data sharing capability. It is possible to store information regarding the survey logically in the database (database schema). However, the file system-based opinion collection does not provide such capability. It is possible to monitor several surveys simultaneously and store/collect/analyze data in real time. However, the file system-based opinion collection does not provide such capability. It is possible to easily search for all information related to previous surveys stored in the database with various search terms. THE BRIEF DESCRIPTION OF THE DRAWINGS [0060] FIG. 1 is a diagram of a system for automatically collecting opinions according to an embodiment of the present invention, [0061] FIG. 2 is a detailed block diagram of an opinion collecting server of FIG. 1 , [0062] FIG. 3 is a detailed block diagram of an opinion inputting terminal of FIG. 1 , [0063] FIG. 4 is a flowchart of a method for collecting electronic voting results and providing an election result according to another embodiment of the present invention, [0064] FIG. 5 is a diagram of an example of a candidate information metadata frame, [0065] FIG. 6 is a diagram of an example of candidate information contents, [0066] FIG. 7 is a diagram of an example of ballot paper contents, [0067] FIG. 8 is a diagram of an example of reply contents generated in step S 445 of FIG. 4 , [0068] FIG. 9 is a flowchart of a method for collecting opinions using an electronic survey and providing a collected result according to another embodiment of the present invention, [0069] FIG. 10 is a diagram of an example of a question metadata frame, [0070] FIG. 11 is a diagram of an example of question contents, [0071] FIG. 12 is a diagram of an example of response contents, and [0072] FIG. 13 is a diagram of an example of the reply contents generated in step S 945 of FIG. 9 . [0073] FIG. 14 is a diagram of an example of metadata extraction of an election voting service according to an ontology classification method, [0074] FIG. 15 is a diagram of a metadata description frame according to RDF, [0075] FIG. 16 is a diagram of a metadata description frame according to XML, [0076] FIG. 17 is a diagram of a metadata description frame according to a relational data model, [0077] FIG. 18 is a diagram of an example of metadata extraction of the opinion poll service according to the ontology classification method, [0078] FIG. 19 is a diagram of a metadata description frame according to the RDF, [0079] FIG. 20 is a diagram of a metadata description frame according to the XML, [0080] FIG. 21 is a diagram of a metadata description frame according to the relational data model, and [0081] FIG. 22 is a diagram of an example for reversely converting the reply contents of a table type to the metadata description frame. [0082] FIG. 23 is a diagram of a system for automatically collecting opinions based on a spread sheet as its file system. [0083] FIG. 24 is another diagram of a system for automatically collecting opinions according to a preferred embodiment of the present invention. [0084] FIG. 25 is a diagram of three different phases of a database data model according to an embodiment of the present invention. [0085] FIG. 26 is a diagram of a database-based system for automatically collecting opinions according to an embodiment of the present invention, which is a combination of a survey information retrieval system and a survey monitoring system. BEST MODE FOR CARRYING OUT THE INVENTION [0086] Hereinafter, the present invention is explained in detail by referring to the drawings. [0087] FIG. 1 is a diagram of a system for automatically collecting opinions according to an embodiment of the present invention. The system for automatically collecting opinions is a system capable of automatically collecting opinions of multiple people and compiling statistics with the collected opinions. [0088] FIG. 24 is another diagram of a system for automatically collecting opinions according to a preferred embodiment of the present invention. It is noted that instead of using a file system as shown in FIG. 23 , FIG. 24 shows that the system uses a database system for storing and collecting user opinions. Here, the database is provided independently from the opinion collecting server 100 . [0089] A representative example of the opinion can include 1) a voting which is the opinion for selecting a particular candidate in an election, 2) opinions of people for a particular agenda, and the like. [0090] Hence, the system for automatically collecting opinions according to embodiments of the present invention can provide 1) a solution for providing an election result by collecting/counting voting results of voters and 2) a solution for researching and collecting opinions of people and then providing statistically processed results. [0091] As shown in FIG. 1 , the system for automatically collecting opinions according to an embodiment of the present invention includes an opinion collecting server 100 and opinion inputting terminals 200 - 1 through 200 -N. [0092] The opinion collecting server 100 is connected with the opinion inputting terminals 200 - 1 through 200 -N to communicate over a network (N). A type of the network N for interconnecting the opinion collecting server 100 and the opinion inputting terminals 200 - 1 through 200 -N are not limited, and can be implemented using an adequate network if necessary. [0093] For example, when the system for automatically collecting opinions according to an embodiment of the present invention is utilized as a system for collecting opinions of employees in a company, the network N can use a LAN. However, when the system for automatically collecting opinions according to an embodiment of the present invention is utilized as a system for collecting voting results in a nationwide election, the network N needs to use a WAN, a mobile communication network, a PSTN, or a combination of some of them. [0094] Also, how the opinion collecting server 100 and the opinion inputting terminals 200 - 1 through 200 -N are connected to the network N is not limited. They can be connected to the network N by wire or by wireless, and a communication protocol is not limited either. [0095] In the system for automatically collecting opinions according to an embodiment, the opinion collecting server 100 inquires of the opinion inputting terminals 200 - 1 through 200 -N about the opinion of a user. [0096] When the opinion inputting terminals 200 - 1 through 200 -N send opinions of users to the opinion collecting server 100 in reply to the inquiry, the opinion collecting server 100 compiles statistics with the received opinions of the users and provides the result. [0097] Hereafter, the opinion collecting server 100 and the opinion inputting terminals 200 - 1 through 200 -N of FIG. 1 are described in further detail, and the opinion collecting server 100 is explained first by referring to FIG. 2 . MODE OF THE INVENTION [0098] FIG. 2 is a detailed block diagram of the opinion collecting server 100 of FIG. 1 . Blocks constituting the opinion collecting server 100 as shown can be implemented using S/W and H/W. Also, some of the blocks constituting the opinion collecting server 100 can be implemented using S/W and the remaining blocks can be implemented using H/W. [0099] The opinion collecting server 100 , as shown in FIG. 2 , includes a metadata extraction unit 105 and a metadata description frame generator 110 on the side of a system service provider, a manager authentication unit 115 , a service selector 120 , a metadata frame converter 125 , a metadata description frame DB 135 , a content generator 140 , a content distributor 145 , a distributed site DB 150 , a reply content receiver 155 , a metadata frame reverse converter 160 , a reply information DB 165 , a statistics compiler 170 , a statistics compiling S/W 175 , a result processor 180 , a real-time monitor 185 , and an information searcher 190 on the side of a manager. [0100] The metadata extraction unit 105 and the metadata description frame generator 110 are a preprocessor to be installed prior to a self system service which furnishes the opinion collecting system service. Originally, metadata indicates data relating to the information. In embodiments of the present invention, the metadata indicates data to be contained in contents necessary for the opinion collecting service, and metadata items indicate metadata property, category, type, and value. [0101] The metadata extraction unit 105 extracts, classifies, and organizes the metadata items required for the automatic opinion collecting service provided by the system for automatically collecting opinions as mentioned above. The metadata items are extracted, classified, and arranged with a methodology using ontology, which shall be explained later. [0102] The ontology in the present invention is a system classifying the metadata items required for the service into hierarchical relationships and premise part relations, and is defined as word representation, which becomes the metadata items of the service (see FIG. 14 and FIG. 18 ). [0103] The metadata description frame generator 110 generates the metadata items relating to the opinion collecting service extracted by the metadata extraction unit 105 using the ontology scheme, as a metadata description frame. [0104] At this time, a metadata description frame scheme can employ at least one of 1) a description method according to Resource Description Framework (RDF), 2) a description method according to eXtensible Hyper Text Markup Language (XHTML) or eXtensible Markup Language (XML), 3) a description method according to a data model of the database, and 4) a description method according to spread sheet. [0105] A metadata description frame structure is necessary to enhance efficiency of the automatic opinion collecting system according to an embodiment of the present invention, and directly involves enhancement of a user interface and easiness of information search. [0106] The metadata description method according to the RDF representation describes the frame of the metadata in a graphical structure by combining basic description units of the metadata into three elements of resource, property, and value. [0107] The metadata description method according to the XHTM or XML representation describes the metadata frame in a tree structure with structural element type, class property, and IDentification (ID) property of the metadata. [0108] Meanwhile, the metadata description method according to the data model representation of the database can describe the metadata frame with the data model scheme of the database, that is, with a hierarchical data model, a network data model, a relational data model, and an object-oriented data model. [0109] A data processing system of the spread sheet type such as excel of Microsoft may be used. [0110] Advantages of the metadata frame description methods according to the RDF, XHTML, and XML representations include high compatibility and high congeniality with semantic web technology which is studied as a next-generation web technology. Meanwhile, the metadata frame description methods according to the database data model and the spread sheet can be mounted using existing stabilized theory techniques and tools. [0111] The metadata description frame generator 110 generates a metadata description frame with the metadata defined by a definition unit of the metadata in the above-described manner, and stores it to the metadata description frame DB 135 . The voting service and the opinion collecting service in the automatic opinion collecting system as above shall be explained in detail by referring to FIGS. 14 through 21 . [0112] The manager authentication unit 115 authenticates whether a rightful manager accesses the opinion collecting server 100 . Herein, the rightful manager indicates a manager who manages and takes charge of the opinion collection via the opinion collecting server 100 or a manager of the corresponding authority in an institution which manages and takes charge of the opinion collection via the opinion collecting server 100 . [0113] When the opinion collecting server 100 is a server for collecting voting results, the rightful manager indicates the person in charge of the election administration, or the person belonging to the institution in charge of the election administration and given the authority. [0114] When the opinion collecting server 100 is a server for collecting opinions, the rightful manager indicates the person authorized to survey opinions, or the person in charge of the corresponding task in an institution authorized to survey opinions. [0115] Herein, the authentication procedure can be performed in various manners. For example, the authentication procedure can be carried out by 1) checking ID/PW, 2) authenticating through a certificate or a digital signature, 3) verifying using an authentication card, USB memory, and the like, and 4) identifying using biometric information (for example, face photo, voice, fingerprint, iris, etc.). [0116] At this time, a) the face photo can be obtained through a PC camera (not shown) of the opinion collecting server 100 , b) the voice can be obtained through a microphone (not shown) of the opinion collecting server 100 , c) the fingerprint can be obtained through a fingerprint reader (not shown) connected to the opinion collecting server 100 , and d) the iris can be obtained through an iris scanner (not shown) connected to the opinion collecting server 100 . [0117] The service selector 120 provides a manager interface for selecting any one of opinion collecting services supplied by the opinion collecting server 100 . This is useful when the opinion collecting server 100 provides several opinion collecting services. [0118] As stated above, the opinion collecting services provided by the opinion collecting server 100 can be classified into a voting result collecting service (electronic voting service) and an opinion collecting service (electronic survey service). Accordingly, the service selector 120 provides the manager interface for selecting any one of the electronic voting service and the electronic survey service. [0119] The manager can select an intended service through the manager interface. At this time, it is understood that the manager is who verified as the rightful manger by the manager authentication unit 115 . [0120] The metadata description frame DB 135 stores metadata description frames. Meanwhile, contents required for the opinion collecting service are 1) opinion determining contents and 2) opinion inputting contents. [0121] Herein, 1) the opinion determining contents are contents containing information to be referred to before the users make a decision, and 2) the opinion inputting contents are contents used for the users to input the determined opinion after making the decision. [0122] The metadata frame converter 125 generates a metadata frame by converting the metadata description frame defined and described in the RDF, XHTML, database, data model, or spread sheet representation in the metadata description frame DB 135 , to a table type which is the user interface form so that the manager or the user can easily obtain and use. The metadata frame converter 125 stores (databases) the generated metadata frame to the metadata description frame DB 135 . [0123] For doing so, the metadata frame converter 125 extracts necessary metadata description frames from the metadata description frames stored to the metadata description frame DB 135 . [0124] Herein, the necessary metadata description frames are 1) metadata description frames for metadata items to be contained in the opinion determining contents and 2) metadata description frames for metadata items to be contained in the opinion inputting contents, for the opinion collecting service selected by the service selector 120 . [0125] Thus, when extracting the metadata description frame, the metadata frame converter 125 refers to which opinion collecting service is selected by the user through the service selector 120 . For example, when the user selects the electronic voting service through the service selector 120 , the metadata frame converter 125 extracts the metadata description frames required for the electronic voting service. By contrast, when the user selects the electronic survey service through the service selector 120 , the metadata frame converter 125 extracts the metadata description frames required for the electronic survey service. [0126] The metadata frame converter 125 generates the metadata frame of the table type by converting the extracted metadata description frame. More specifically, the metadata frame converter 125 generates the metadata frame of the table type including metadata items corresponding to the extracted metadata description frame. [0127] In result, the metadata frame converter 125 generates 1 ) the opining determining metadata frame including the metadata items for the opinion determining contents and 2) the opinion inputting metadata frame including the metadata items for the opinion inputting contents. [0128] The content generator 140 includes actual metadata corresponding to the metadata items contained in the metadata frame generated by the metadata frame converter 125 . That is, the contents can indicate the metadata frame including the actual metadata. [0129] The contents generated by the content generator 140 are the opinion determining contents and the opinion inputting contents. [0130] The content distributor 145 distributes the opinion determining contents and the opinion inputting contents generated by the content generator 140 , only to the corresponding persons of the user terminals 200 - 1 through 200 -N. [0131] To distribute only to the corresponding persons of the user terminals 200 - 1 through 200 -N, the content distributor 145 refers to the distributed site DB 150 . This is because the distributed site DB 150 includes addresses of users for the opining collection. [0132] Herein, the address of the user indicates a mobile phone number, an IP address, and an E-mail address of the user. The mobile phone number is appropriate when the user terminal is a mobile phone, the IP address is appropriate when the user terminal is a PC and the E-mail address is appropriate when the user terminal is either. [0133] The user terminal receiving the distributed contents from the content distributor 145 transmits reply contents in response, which is to be explained. The reply contents include the opinion of the user of the user terminal. [0134] Then, the reply content receiver 155 of the opinion collecting server 100 of FIG. 2 receives the reply contents transmitted by the user terminal. [0135] The metadata frame reverse converter 160 reversely converts the reply metadata frame of the table type contained in the reply contents received by the reply content receiver 155 , to the metadata description frame of the RDF, XHTML, database model, or spread sheet form, and thus generates the metadata description frame. The metadata frame reverse converter 160 stores (databases) the metadata description frame to the reply information DB 165 and also sends it to the real-time monitor 185 . [0136] Meanwhile, the statistics compiler 170 extracts the user's opinion contained in the reply contents received by the reply content receiver 155 , compiles the statistics by analyzing the extracted opinion, and then stores the result to the reply information DB 165 . At this time, the statistics compiler 170 uses the statistics compiling S/W. [0137] The result processor 180 generates the statistics compiling result of the statistics compiler 170 as visual information. [0138] The real-time monitor 185 processes the reception count state of the reply content receiver 155 as visual information and provides the visual information to the manager in real time. Also, the real-time monitor 185 provides the visual information of the statistics compiling result generated by the result processor 180 to the manager. [0139] Also, the real-time monitor 185 can send a reply request message to user terminals which do not send the reply contents. In so doing, the message can include a total reply rate and a period for reply. [0140] Meanwhile, the transmission/contents of the message can vary according to whether the distributed contents are received. For example, it is possible to send the reply request message only to the user terminal which receives and confirms the contents but does not send the reply contents, and not to send the reply request message to the user terminal which does not receive the contents. This is because the probability of the reply is high when the reply is demanded in the former case. [0141] The information searcher 190 functions to search the metadata item and the metadata which are the information contained in the metadata frame, for example, to search “candidate” corresponding to “candidate”, “affiliated party”, and “00 party”, or search a search term meeting a certain condition such as “candidate” won “00 election”. [0142] So far, the opinion collecting server 100 of FIG. 2 has been described in detail. Hereafter, the opinion inputting terminals 200 - 1 through 200 -N of FIG. 1 are elucidated by referring to FIG. 3 . [0143] Since the opinion inputting terminals 200 - 1 through 200 -N can be implemented in the same structure, the single opinion inputting terminal is solely illustrated in FIG. 3 and represented by a reference numeral 200 . [0144] FIG. 25 shows three different phases of a database data model of the present invention. The first phase is to design a concept of a particular survey database. The first phase includes steps of extracting, classifying, and organizing conceptual design data required for collecting the opinions of the users into vocabulary data as metadata items. The second phase is to design the survey database logically and physically. The second phase includes steps of generating metadata description frames by using the metadata items indicating properties of data relating to the opinion collecting service and constructing a database of the metadata description frames. Finally, the third phase is to construct the survey database. The third phase includes steps of databasing the generated metadata description frame. [0145] FIG. 3 is a detailed block diagram of the opinion inputting terminal 200 . Blocks constituting the opinion inputting terminal 200 as shown can be implemented using S/W and H/W. Also, some of the blocks constituting the opinion inputting terminal 200 can be implemented using S/W and the remaining blocks can be implemented using H/W. [0146] The opinion inputting terminal 200 , as shown in FIG. 3 , includes a content receiver 210 , a content reader 220 , an opinion input unit 230 , a reply content generator 240 , a user authenticator 250 , and a reply content transmitter 260 . [0147] The content receiver 210 receives the contents distributed by the content distributor 145 of the aforementioned opinion collecting server 100 . Since the contents distributed by the content distributor 145 are the opinion determining contents and the opinion inputting contents, the contents received by the content receiver 210 are also the opinion determining contents and the opinion inputting contents. [0148] The content reader 220 processes to display the opinion determining contents received by the content receive 210 in a display so that the user can read them. [0149] The opinion input unit 230 processes to convert the opinion inputting contents received by the content receiver 210 to a user interface through which the user can input his/her opinion as reading and to show it in the display. [0150] Hence, the user can input his/her opinion using the opinion inputting contents. The opinion input unit 230 forwards the user's opinion input through the opinion inputting contents to the reply content generator 240 . [0151] The reply content generator 240 generates the opinion inputting contents including the user's opinion received via the opinion input unit 230 , as the reply contents. [0152] The user authenticator 250 authenticates whether the user who inputs the opinion is the rightful user. Herein, the rightful user indicates the person who has the right or the authority to input the opinion through the opinion inputting terminal 200 . [0153] When the opinion collecting service is the electronic voting service, the rightful user is the voter who has the right to vote. When the opinion collecting service is the electronic survey service, the rightful user indicates the person belonging to the sample to survey or the person having the voting right. [0154] At this time, the authentication procedure can be performed using various methods as in the manager authentication unit 115 of the opinion collecting server 100 as stated above. [0155] Accordingly, the authentication procedure can be carried out by 1) checking JD/PW, 2) authenticating with a certificate or a digital signature, 3) verifying using an authentication card, USB memory, and the like, and 4) identifying using biometric information (for example, face photo, voice, fingerprint, iris, etc.). [0156] At this time, a) the face photo can be obtained through a PC camera (not shown) of the opinion inputting terminal 200 , b) the voice can be obtained through a microphone (not shown) of the opinion inputting terminal 200 , c) the fingerprint can be obtained through a fingerprint reader (not shown) connected to the opinion inputting terminal 200 , and d) the iris can be obtained through an iris scanner (not shown) connected to the opinion inputting terminal 200 . [0157] When the user authenticator 250 verifies the rightful user, the reply content transmitter 260 sends the reply contents generated by the reply content generator 240 to the reply content receiver 155 of the aforementioned opinion collecting server 100 . [0158] Hereafter, a process for collecting the voting result by conducting the electronic voting through the automatic opinion collecting system of FIG. 1 is explained in detail by referring to FIG. 4 . [0159] FIG. 4 is a flowchart of a method for collecting the electronic voting result and providing the election result according to another embodiment of the present invention. [0160] In the flowchart of FIG. 4 , the steps shown in the left side are performed by the opinion collecting server 100 , and the steps shown in the right side are performed by the opinion inputting terminal 200 . [0161] As shown in FIG. 4 , the manager authentication unit 115 of the opinion collecting server 100 authenticates whether the person accessing the opinion collecting server 100 is the rightful manager (S 405 ). [0162] When the rightful manager is authenticated in the step S 405 and the manager selects the electronic voting service through the manager interface provided by the service selector 120 (S 410 ), the metadata frame converter 125 generates the candidate information metadata frame and the ballot paper metadata frame (S 415 ). [0163] Herein, a preferable candidate information metadata frame is a metadata frame of the table type including the metadata items relating to the candidate information contents, and an example of the candidate information metadata frame is shown in FIG. 5 . [0164] As shown in FIG. 5 , the candidate information metadata frame includes, as the candidate information metadata items, “vote title”, “manager”, “election date”, “symbol”, “name of candidate”, “age of candidate”, “party of candidate”, “academic records of candidate”, “career of candidate”, and “photo of candidate”. [0165] These metadata items correspond to properties of the information to be referred to by the user to determine the candidate. That is, the metadata items correspond to the properties of the necessary information for the opinion decision of the user who casts a vote, as explained earlier. [0166] Meanwhile, the ballot paper metadata frame is the metadata frame including the metadata items required for the user to cast a vote. [0167] Referring back to FIG. 4 , after step S 415 , the content generator 140 generates the candidate information contents and the ballot paper contents by including the actual metadata corresponding to the metadata items contained in the metadata frame generated in step S 415 (S 420 ). [0168] FIG. 6 depicts an example of the candidate information contents. The candidate information contents of FIG. 6 is generated by including information of the actual election and information of the actual candidate to the candidate information metadata frame of the table type of FIG. 6 . [0169] More specifically, the candidate information contents of FIG. 6 include 1) “8th parliamentary election” as the actual metadata for the metadata item “vote title”, 2) “parliamentary election management committee” as the actual metadata for the metadata item “manager”, 3) “April 7, 20 12” as the actual metadata for the metadata item “election date”, 4) “No. 1” as the actual metadata for the metadata item “symbol”, 5) “Lee Mong Yong” as the actual metadata for the metadata item “name of candidate”, 6) “42” as the actual metadata for the metadata item “age of candidate”, 7) “XX party” as the actual metadata for the metadata item “party of candidate”, 8) “graduated from Good Elementary School in 1985/graduated from Outstanding University with economics major in 1995/obtained master degree in Harvard University in U.S.A. in 2000” as the actual metadata for the metadata item “academic records of candidate”, 9) “XX Electronics researcher/XX governor/Oth member of the National Assembly” as the actual metadata for the metadata item “career of candidate”, and 1 0) a photo of the candidate as the actual metadata for the metadata item “photo of candidate”. [0170] Meanwhile, FIG. 7 depicts an example of the ballot paper contents. As shown in FIG. 7 , the ballot paper contents include the metadata items required for the voting and the actual metadata of the metadata items, and accordingly, it is noted that the ballot paper contents can function as the ballot paper. [0171] The metadata items in the ballot paper contents of FIG. 7 are “vote title”, “election date”, “symbol”, “name”, and “vote column”. In the ballot paper contents, 1) the actual metadata for the metadata item “vote title” is “8th parliamentary election”, 2) the actual metadata for the metadata item “election date” is “April 7, 20 12”, 3) the actual metadata for the metadata item “symbol” is “1”, “2”, “3”, “4”, “5”, “6”, and “7”, and 4) the actual metadata for the metadata item “name of candidate” is “Lee Mong Yong”, “Kim Cheal Soo”, “Lee Young Hee”, “Park Young Seok”, “Choi Jin Soo”, “Jung Sung Hoon”, and “Ha Dong Soo”. [0172] Meanwhile, the actual metadata for “vote column” is not recorded, which is recorded in step S 445 according to the voting of the user input in step S 440 to be explained. [0173] Referring back to FIG. 4 , after step S 420 , the content distributor 145 distributes the candidate information contents and the ballot paper contents generated in step S 420 to the user terminal 200 (S 425 ). As distributing in step S 425 , the content distributor 145 refers to the distributed site DB 150 . [0174] Then, the content receiver 210 of the opinion inputting terminal 200 receives the candidate information contents and the ballot paper contents distributed in step S 425 (S 430 ). [0175] The content reader 220 shows the candidate information contents received in step S 430 in the display so that the user can read them (S 435 ). [0176] The opinion input unit 230 processes to convert the ballot paper contents received in step S 430 to the user interface through which the user can read to cast a vote, and to display in the display (S 440 ). [0177] Hence, the user can cast a vote for his/her intended candidate using the ballot paper contents. [0178] Then, the reply content generator 240 generates the reply contents with the ballot paper contents including the candidate selected by the user in step S 440 (S 445 ). [0179] An example of the reply contents generated in step S 445 is shown in FIG. 8 . The reply contents of FIG. 8 are the ballot paper contents including “candidate No. 1 Lee Mong Yang”. [0180] Referring back to FIG. 4 , after step S 445 , the user authenticator 250 authenticates whether the user voted in S 440 is the rightful user (S 450 ). [0181] When the rightful user is confirmed in step S 450 (S 450 -Y), the reply content transmitter 260 transmits the reply contents generated in step S 445 to the reply content receiver 155 of the opinion collecting server 100 (S 455 ). [0182] Then, the reply content receiver 155 of the opinion collecting server 100 receives the reply contents transmitted in step S 455 (S 460 ). [0183] The reply contents received in step S 460 are stored to the reply information DB 165 . [0184] Meanwhile, it is possible to send the reply contents received in step S 460 to the real-time monitor 185 as well so that the real-time monitor 185 outputs the vote count state in real time. [0185] The statistics compiler 170 extracts the user's voting result in the reply contents received in step S 460 , and compiles the statistics with the extracted voting result (S 465 ). [0186] Then, the result processor 180 generates the statistically compiled result of step S 465 as the visual information, and the real-time monitor 185 displays the generated visual information in the display in real time and provides it to the manager in real time (S 470 ). [0187] Hereafter, a process for collecting opinions through the electronic survey using the automatic opinion collecting system of FIG. 1 is explained in detail by referring to FIG. 9 . [0188] FIG. 9 is a flowchart of a method for collecting opinions using the electronic survey and providing the collection result according to another embodiment of the present invention. [0189] In the flowchart of FIG. 9 , the steps shown in the left side are performed by the opinion collecting server 100 , and the steps shown in the right side are performed by the opinion inputting terminal 200 . [0190] As shown in FIG. 9 , the manager authentication unit 115 of the opinion collecting server 100 authenticates whether the person accessing the opinion collecting server 100 is the rightful manager (S 905 ). [0191] When the rightful manager is confirmed in step S 905 (S 905 -Y) and the manager selects the electronic survey service through the manager interface provided by the service selector 120 (S 910 ), the metadata frame converter 125 generates the question metadata frame and the response metadata frame (S 915 ). At this time, the question can include at least one of a multiple-choice question and a short-answer question. [0192] Herein, the question metadata frame is the metadata frame including the metadata items for the question contents, and FIG. 10 shows an example of the question metadata frame. [0193] As shown in FIG. 10 , the question metadata frame includes, as the question metadata items, “title”, “manager” “question 1”, “question 2”, . . . , “respondent”, and “date of response”. [0194] The metadata items correspond to the properties of the information to refer to when the user determines the opinion and other basic information. [0195] Meanwhile, the response metadata frame is the metadata frame including the metadata items required for the user to input the response to the question. [0196] Referring back to FIG. 9 , after step S 915 , the content generator 140 generates the question contents and the response contents by including actual metadata corresponding to the metadata items contained in the metadata frame generated in step S 915 (S 920 ). [0197] FIG. 11 depicts an example of the question contents. The question contents in FIG. 11 are generated by including actual basic information and actual questions to the question metadata frame of FIG. 10 . [0198] Specifically, the question contents of FIG. 11 include 1) “MT opinion survey” as the actual metadata for the metadata item “title”, 2) “student council” as the actual metadata for the metadata item “manager”, 3) “new term MT place . . . Mt. Mai” as the actual metadata for the metadata item “question 1”, 4) “MT date . . . April 15” as the actual metadata for the metadata item “question2”, 5) “Lee Mong Yong” as the actual metadata for the metadata item “respondent”, and 6) “20 12.0.0” as the actual metadata for the metadata item “date of response”. [0199] Meanwhile, FIG. 12 depicts an example of the response contents. As shown in FIG. 12 , the response contents include metadata items required for inputting responses for the questions and actual metadata of the metadata items. Hence, the response contents can function as a response collecting paper. [0200] The metadata items in the response contents of FIG. 12 are “title”, “date”, “question 1”, “question2”, . . . . In the response contents, 1) the actual metadata for the metadata item “title” is “MT opinion survey”, and 2) the actual metadata for the metadata item “date” is “2012.0.0”. [0201] Meanwhile, while the actual metadata for the metadata items “question 1” and “question2” are not included, they are included in step S 945 according in step S 945 to the response of the user input in step S 940 to be explained. [0202] Referring back to FIG. 9 , after step S 920 , the content distributor 145 distributes the question contents and the response contents generated in step S 920 to the user terminal 200 (S 925 ). In the distribution of step S 925 , the content distributor 145 refers to the distributed site DB 150 . [0203] Then, the content receiver 210 of the opinion inputting terminal 200 receives the question contents and the response contents distributed in step S 925 . [0204] The content reader 220 shows the question contents received m step S 930 in the display so that the user can read them (S 935 ). [0205] The opinion inputting unit 230 converts the response contents received in step S 930 to the user interface through which the user can input the response for the question while reading it, and processes to show it in the display (S 940 ). [0206] Hence, the user can input his/her intended response using the response contents. [0207] Then, the reply content generator 240 generates the reply contents with the response contents including the response input by the user in step S 940 (S 945 ). [0208] An example of the reply contents generated in step S 945 is shown in FIG. 13 . The reply contents of FIG. 13 are the response contents which input “Mt. Songni” in response to “new term MT place . . . ” and “April 15” in response to “MT date . . . ”. [0209] Referring back to FIG. 9 , after step S 945 , the user authenticator 250 authenticates whether the user responding in step S 940 is the rightful user (S 950 ). [0210] When confirming the rightful user in step S 950 , the reply content transmitter 260 transmits the reply contents generated in step S 945 to the reply content receiver 155 of the opinion collecting server 100 (S 955 ). [0211] The reply content receiver 155 of the opinion collecting server 100 receives the reply contents transmitted in step S 955 (S 960 ). [0212] The reply contents received in step S 960 are stored to the reply information DB 165 . [0213] Meanwhile, it is possible to send the reply contents received in step S 960 also to the real-time monitor 185 so that the real-time monitor 185 outputs the response count state in real time. [0214] The statistics compiler 170 extracts the user's response in the reply contents received in step S 960 , and compiles the statistics with the extracted response (S 965 ). [0215] The result processor 180 generates the visual information with the statistically compiled result of step S 965 , and the real-time monitor 185 shows the generated visual information in the display in real time to provide to the manager in real time (S 970 ). [0216] The exemplary embodiments explained so far can be applied to the public opinion poll. [0217] The opinion inputting terminal 200 in the exemplary embodiments can be implemented using the PC and portable communication equipment such as mobile phone or PDA. [0218] Meanwhile, the order of the manager authenticating step S 405 and the user authenticating step S 450 in FIG. 4 can be realized differently. For example, the manager authenticating step S 405 can be performed any time before step S 425 , and the user authenticating step S 450 can be performed before step S 435 as well. [0219] This also applies to the manager authenticating step S 905 and the user authenticating step S 950 in FIG. 9 . [0220] Hereafter, the necessary functions of the automatic opinion collecting system provider of the present invention before the service provision, that is, the functions of the metadata extraction unit 105 and the metadata description frame generator 110 of FIG. 2 are elucidated. [0221] FIG. 14 depicts an example of the election voting ontology classification as the method for databasing the item relating to the electronic voting in the automatic opinion collecting system according to an embodiment of the present invention. Referring to FIG. 14 , the properties of the resource ‘election voting’ include ‘presidential election’, ‘election for member of the National Assembly’, and so on, the resource ‘election for member of the National Assembly’ includes the properties ‘manager’, ‘election title’, ‘election date’, and so on, which contain (input) instance. “SubClassOF” in FIG. 14 is the expression indicating subsumption relation that the higher subsumes the lower. [0222] FIG. 15 depicts the relations between the elements of the ‘election voting’ related metadata of FIG. 14 described and expressed using the RDF. In FIG. 15 , the graph is drawn with three elements of the resource, the property, and the value. [0223] FIG. 16 redescribes and reexpresses the metadata ‘election voting’ described and expressed using the RDF in FIG. 14 , using the XML. FIG. 17 is a diagram of the metadata frame according to the relational data model of the database. The metadata frame according to the spread sheet type can be described similarly to the relation data model. [0224] FIG. 18 is a diagram of the metadata items according to the ontology representation for defining and extracting the metadata for “public opinion poll execution” in the automatic opinion collecting system according to an embodiment of the present invention. [0225] FIG. 19 is a diagram of the metadata frame according to the ontology representation with the RDF, and FIG. 20 is a diagram of the metadata frame according to the ontology representation with the XML. FIG. 21 is a diagram of a metadata frame according to the ontology representation with the relational data model. [0226] FIG. 22 is a diagram of an example for reversely converting the reply contents of the table type to the metadata description frame. This is the function of the metadata frame reverse converter 160 and corresponds to the reply contents of FIG. 8 described using the XML which is one of the metadata description frame representations. [0227] For reference, “ex” in the aforementioned drawings is a “prefix” indicating the metadata, and is hypothetical. [0228] While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

A database-based system is provided for performing an opinion collecting service that provides information necessary for deciding and presenting opinions of users and collecting information containing the opinions of the users. The system consists of a server, a plurality of user terminals connected to the server over a network, and a database configured to store information containing the opinions of the users. The database for the system is designed with three different phases: 1) conceptual design of a survey database; 2) logical/physical design for the survey database; and 3) construction of the survey database.

TECHNICAL FIELD The present disclosure generally relates to a relay, and more particularly, to a magnetic latching relay with a parallel-type magnetic circuit. BACKGROUND A relay is an automatic switch device having isolation function, widely applied in communication, automobiles, automatic control, household appliances and other fields, and is one of the most important control devices. Due to demands in energy preservation and environment protection, magnetic latching relays are applied to ever wide areas. Common relays require to be developed with magnetic latching features. Generally, for a typical clap-type relay, an iron core (or an iron yoke) is divided into two parts. A permanent magnet is connected between the two parts, to form a series-type magnetic circuit. Upon excitation of a coil, the magnetic circuit is closed, and a magnetic force generated by the permanent magnet can keep an armature in closed state. FIG. 1 is a schematic structural diagram of a magnetic circuit of a magnetic-latching-type electromagnet relay in the prior art. As shown in FIG. 1 , the magnetic circuit of the electromagnet relay includes a spring sheet 101 (which can form a part of an output circuit of the relay), an armature 102 , an iron yoke 103 , an iron core 104 , a coil 105 and a permanent magnet 106 . The iron core 104 passes through the coil 105 . The permanent magnet 106 is fixed between the iron core 104 and the iron yoke 103 . The armature 102 and the spring sheet 101 are riveted together in advance, and riveted onto the iron yoke 103 . The permanent magnet 106 generates a permanent magnetic circuit which starts from an N pole of the permanent magnet, passes through the iron core 104 , an air gap, the armature 102 , the iron yoke 103 , reaches an S pole of the permanent magnet. Upon excitation, the coil 105 generates a magnetic field which passes through the iron core 104 , the air gap, the armature 102 , the iron yoke 103 and the S-N of the permanent magnet. When the permanent magnet filed and the magnetic field generated by the coil is in the same direction, the magnetic forces will add to each other to form a force which overcomes the counter force of the spring sheet 101 , so as to cause the armature 102 and the iron core 104 to attract each other. After the excitation of the coil 105 stops, the magnetic field generated by the coil will disappear, and the permanent magnetic field will provide a retention force to keep the armature 102 and the iron core 104 in the attracted state. When a reverse current flows through the coil, the coil 105 generates a magnetic field which passes through the iron core 104 , the N-S of the permanent magnet, the iron yoke 103 and the armature 102 . Thus, the magnetic field generated by the coil is opposite to the direction of the permanent magnetic field, and weakens the permanent magnetic force. Under the “cooperation” of the counter force of the spring sheet 101 , the spring sheet 101 brings the armature 102 to be reset. Such a series-type magnetic circuit has the following defects. 1. The permanent magnet always causes the armature to be attracted to the iron core, and even though the spring sheet has a large counter force, but a pressure on the contact point at a normal-close terminal of the product is relatively small. Therefore, load capability of the fixed closed terminal is poor, and the product relay has a poor resistance against impact and vibration. 2. After the coil is excited for reset, the magnetic force of the permanent magnet still generates a strong attraction force to the armature. Therefore, it requires a large reset force to reset the armature to reset to a released state. If the magnetic force does not match the reset force, the coil may require a small setting voltage and a large resetting voltage, or the coil may fail to be reset. SUMMARY The objective of the present disclosure is to overcome the deficiency in the related art. In one aspect, the objective is to provide a magnetic latching relay with a parallel-type magnetic circuit in which two parallel permanent magnetic paths are formed, one of the paths is for providing a suitable attraction force to the armature, so as to keep balance with a counter force provided by a movable spring sheet and to achieve bistability or state switching more stably. In another aspect, the objective of the present disclosure is to provide a magnetic latching relay with a parallel type magnetic circuit in which a magnetic isolation recess is provided on the iron yoke and a cut is provided on the pole shoe of the iron core, to adjust the retention force generated by the iron core to the armature at the position of the armature, thus keeping balance between the magnitudes of resetting voltage and the setting voltage of the magnetic latching relay as much as possible. In still another aspect, the objective of the present disclosure is to improve the structure of the coil rack and the pole shoe of the iron core. Thus, on one hand, it can increase the creepage distance between the iron core and the fixed spring sheet, preventing electrical accidents caused by unwanted conduction of the movable contact point and the fixed contact point due to accumulation of metal spatters of the contact points. On the other hand, it can significantly improve the impact resistance of the relay. In yet still another aspect, the objective of the present disclosure is to improve the structure of the bobbin of the coil rack, to effectively isolate the first circle of an enameled wire and the last circle of the enameled wire, avoiding defects in the related art which are caused by placing the first circle of the enameled wire and the last circle of the enameled wire together. The technical solutions of the present disclosure for solving the technical problems are as follows. A clapper relay, including a magnetic circuit portion and a movable spring portion, characterized in that, the magnetic circuit portion includes an iron core, an armature, an iron yoke, a permanent magnet, a magnetic conductor member, a coil and a coil rack; the iron yoke is L shaped, formed by a first yoke parallel to the iron core and a second yoke perpendicular to the iron core; the coil is wound on the coil rack, the iron core passes through the coil rack, a lower end of the iron core is secured to the second yoke; the armature is movably mounted to a hinge portion of the iron yoke, an air gap is formed between one end of the armature and an upper end of the iron core; one end of the magnetic conductor member is connected to the first yoke, the other end of the magnetic conductor member is connected to first yoke through the permanent magnet; the movable spring portion includes a movable spring sheet and a movable contact point, the movable spring sheet formed with a first side and a second side, an elastically bendable angle is formed between the first side and the second side; the armature is secured to the second side, the first yoke is secured to the first side, the armature is flexibly connected to the first yoke via the movable spring sheet; the movable contact point is secured to the second side, wherein the permanent magnet and the magnetic conductor member, the first yoke, the second yoke, the iron core and the armature form two parallel permanent magnetic paths; the coil and the iron core form a control magnetic path, to control the opening and closing of the air gap; the permanent magnetic paths provide a force to maintain the air gap to be closed; the movable spring sheet provides a counter force to maintain the air gap to be opened. According to an embodiment of the present disclosure, at least one magnetic isolation portion is provided on the first yoke which is between a joint of the first yoke and the permanent magnet and a joint of the first yoke and the magnetic conductor member, the magnetic isolation portion is configured to increase a magnetic resistance of the magnetic circuit portion, and to adjust balance between magnitudes of setting voltage and resetting voltage of the relay by adjusting an opening size of a magnetic isolation recess. According to an embodiment of the present disclosure, an upper end of the iron core is provided with a pole shoe, a cut is provided at a side of the pole shoe, a size of the cut and/or the opening size of the magnetic isolation recess can be adjusted to regulate balance between magnitudes of a setting voltage and a resetting voltage of the relay. According to an embodiment of the present disclosure, one end of the magnetic conductor member is provided with a contact surface for contacting the first yoke. According to an embodiment of the present disclosure, the contact surface of the magnetic conductor member is provided with a boss for positioning with the first yoke, the first yoke is provided with a hole for fitting with the boss of the magnetic conductor member; the boss of the magnetic conductor member is fitted in the hole of the first yoke, and secured thereto via rivet or welding. According to an embodiment of the present disclosure, the permanent magnet is secured to the other end of the magnetic conductor member, and the other end of the magnetic conductor member is provided with a bulge for securing the permanent magnet. According to an embodiment of the present disclosure, the relay further includes a fixed spring portion, the fixed spring portion includes a fixed spring sheet and a fixed contact point secured on the fixed spring sheet; an upper end plate of the coil rack extends to a side where a mounting portion is disposed, the fixed spring sheet is mounted in the mounting portion, the movable contact point is mounted at a position in the mounting portion where matches with the position of the fixed contact point; at least one shielding wall is provided on the coil rack and between the through holes and the mounting portion, to separate a pole shoe at the through hole of the coil rack and the fixed spring sheet at the mounting portion. According to an embodiment of the present disclosure, the shielding wall is disposed close to the through hole, and corresponding to the armature secured to the movable spring sheet, a height of the shielding wall is not lower than a bottom of the armature when the relay is reset, in order to prevent the armature from moving to a direction where the movable contact point contacts the fixed contact point. According to an embodiment of the present disclosure, there are provided two shielding walls, and a groove is formed between the two shielding walls for collecting spatters of the contact points, wherein one of the shielding walls is disposed close to the through hole, and corresponding to the armature secured to the movable spring sheet, a height of the shielding wall is not lower than a bottom of the armature when the relay is reset, in order to prevent the armature from moving to a direction where the movable contact point contacts the fixed contact point. According to an embodiment of the present disclosure, the shielding wall is integrated with the coil rack. According to an embodiment of the present disclosure, the coil rack includes a bobbin, one end of the bobbin is connected to a lower terminal plate, the other end of the bobbin is connected to an upper terminal plate, a first pin, a second pin and a third pin are respectively mounted on the lower terminal plate; a groove for guiding an enameled wire is provided at an inner side of the lower terminal plate which is between the bobbin and the second pin, one end of the groove is connected to the bobbin, and the other end of the groove leads to the second pin. According to an embodiment of the present disclosure, a boss is provided at an inner side of the lower terminal plate which extends from the bobbin to the second pin, a support wall is provided at a side of the boss, and the groove for guiding an enameled wire is surrounded and thus formed by the support wall and the boss. According to an embodiment of the present disclosure, an inclined plate is provided at an inner side of the lower terminal plate, the inclined plate is gradually inclined in a direction from the bobbin to the second pin; the boss and the support wall are respectively disposed at the middle of the inclined plate and a side of the inclined plate. According to an embodiment of the present disclosure, a first cover plate which can press and seize the enameled wire is mounted at the inner side of the lower terminal plate and between the first pin and the bobbin. According to an embodiment of the present disclosure, neither of an upper surface of the boss and an upper surface of the support wall is higher than an upper surface of the first cover plate. According to an embodiment of the present disclosure, a second cover plate which can press and seize the enameled wire is mounted at the inner side of the lower terminal plate and between the third pin and the bobbin. According to an embodiment of the present disclosure, neither of the upper surface of the boss and the upper surface of the support wall is higher than an upper surface of the second cover plate. It can be seen from the above description of the present disclosure that, compared with related art, the present disclosure has the following advantageous effects. According to an embodiment, due to the effect of the magnetic conductor member, the magnetic flux generated by the permanent magnet is divided into two paths and both of the two paths of magnetic fluxes are adjustable. Thereby, it can solve the problem that in the series-type magnetic circuit, there is only one path which cannot be adjusted, and the permanent magnet in the resetting position will keep a large attraction force to the armature and reduce the pressure on the contact points of the normal-close terminal and weaken the load capability of the fixed closed terminal and the product relay has a poor resistance against impact and vibration. According to an embodiment, the first yoke is provided with a magnetic isolation recess for increasing the magnetic resistance of the magnetic circuit, and a portion of the pole shoe of the iron core is cut off. The size of area of the cut (the portion cut off) can be adjusted to, together with the magnetic isolation recess, regulate the balance between the magnitudes of the setting voltage and resetting voltage of the relay. The size of the magnetic isolation recess of the iron yoke can be adjusted to regulate the balance between the magnitudes of the setting voltage and resetting voltage of the relay. However, the magnetic isolation recess cannot be increased infinitely. That is, the magnetic conduction cross sectional area at either side of the magnetic isolation recess cannot be reduced infinitely. Therefore, the magnitudes of the setting voltage and the resetting voltage of the relay cannot be regulated without limit. For a magnetic latching relay, it is generally desirable to make the resetting voltage to be approximate to the setting voltage as much as possible. Therefore, in order to increase the resetting voltage, in the prevent disclosure, a portion of the pole shoe of the iron core is cut off. According to a magnetic circuit principle, the smaller the area of the pole shoe of the iron core is, the larger the retention force (the magnetic attraction force) on the armature when the armature is at the setting position is, and the larger the resetting voltage required is. Accordingly, the magnitudes of the resetting voltage and the setting voltage can be balanced (to make the resetting voltage to be approximate to the setting voltage in the value) as much as possible. According to an embodiment, a shielding wall is provided on the coil rack between the fixed spring sheet and the iron core. After the movable contact point and the fixed contact point are burned, metal spatters of the movable contact point and the fixed contact point can be blocked by the shielding wall, to prevent the metal spatters from drifting from the contact points to the iron core. A groove formed between the two shielding walls and a region between the shielding wall and the fixed contact point can also be configured to collect the metal spatters of the contact points. Thereby, the creepage distance between the movable contact point and the fixed contact point as well as the dielectric Strength can be improved, and it can effectively prevent electrical accidents caused by unwanted conduction of the movable contact point and the fixed contact point due to accumulation of metal spatters of the contact points. The shielding wall is disposed close to the through hole, and corresponding to the armature which is secured to the movable spring sheet. The height of the shielding wall is not lower than the bottom of the armature when the relay is reset. When the relay is subject to an impact in a length direction, the armature will move toward the contact points. Due to the presence of the shielding wall, the armature is limited in the length direction. Thus, the armature and the movable contact point will not displace from normal positions due to the impact, significantly improving the impact resistance of the relay. According to an embodiment, a groove for guiding the enameled wire is surrounded and thus formed by a boss and a support wall. The bottom of the groove is an inclined plate. One end of the groove is connected to the bobbin, one end of the groove leads to the second pin. Thus, in winding the first circle of the outer circles of the enameled wire, the enameled wire is placed on the inclined plate. In winding the last circle of the outer circles of the enameled wire, due to the effect of the boss and the support wall, the last circle of the enameled wire can be held up, to form an air gap between the first circle of the enameled wire and the last circle of the enameled wire, thus avoiding an unfavorable situation of the first circle and the last circle being directly placed together in winding the out circles. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural diagram of a magnetic circuit portion of a magnetic-latching-type electromagnet relay in the prior art; FIG. 2 is an exploded view of the configuration according to an embodiment of the present disclosure; FIG. 3 is a schematic structural diagram of a magnetic circuit portion according to an embodiment of the present disclosure; FIG. 4 is a schematic structural diagram of an iron yoke of the magnetic circuit portion according to an embodiment of the present disclosure; FIG. 5 is a schematic structural diagram of an iron yoke of the magnetic circuit portion according to an embodiment of the present disclosure, with one portion removed; FIG. 6 is a schematic structural diagram of a magnetic conductor member of the magnetic circuit portion according to an embodiment of the present disclosure; FIG. 7 is a side view of the magnetic conductor member of the magnetic circuit portion according to an embodiment of the present disclosure; FIG. 8 is a schematic structural diagram of an iron core of the magnetic circuit portion according to an embodiment of the present disclosure; FIG. 9 is a top view of an iron core of the magnetic circuit portion according to an embodiment of the present disclosure; FIG. 10 is a schematic circuit diagram of the magnetic circuit portion according to an embodiment of the present disclosure, in a resetting state and when the coil is powered off; FIG. 11 is a schematic circuit diagram of the magnetic circuit portion according to an embodiment of the present disclosure, in a resetting state and when the coil is powered with a setting voltage; FIG. 12 is a schematic circuit diagram of the magnetic circuit portion according to an embodiment of the present disclosure, in a setting state and when the coil is powered off; FIG. 13 is a schematic circuit diagram of the magnetic circuit portion according to an embodiment of the present disclosure, in a setting state and when the coil is powered with a resetting voltage; FIG. 14 is a cross sectional view of an embodiment of the present disclosure; FIG. 15 is a schematic structural diagram of a coil rack according to an embodiment of the present disclosure, mainly showing an upper end plate; FIG. 16 is a top view of the coil rack according to an embodiment of the present disclosure, mainly showing an upper end plate; FIG. 17 is a schematic diagram of the coil rack according to an embodiment of the present disclosure, with an iron core and a fixed spring assembled; FIG. 18 is a partial structural diagram of an armature and contact mechanism according to an embodiment of the present disclosure; FIG. 19 is a perspective diagram of a coil rack according to an embodiment of the present disclosure; FIG. 20 is a schematic diagram of a coil rack when winding inner circles of an enameled wire according to an embodiment of the present disclosure; FIG. 21 is a schematic diagram of a coil rack when winding outer circles of an enameled wire according to an embodiment of the present disclosure; FIG. 22 is a side view of a coil rack when winding outer circles of an enameled wire according to an embodiment of the present disclosure; and FIG. 23 is a schematic diagram of a coil rack when inner circles and outer circles of an enameled wire have been wound according to an embodiment of the present disclosure. DETAILED DESCRIPTION Representative embodiments showing characteristics and advantages of the present disclosure will be described in detail in the following description. It should be understood that, the present disclosure can be varied with various embodiments without departing from the scope of the present disclosure. The description and the illustration are merely for explanation, rather than for limitation of the present disclosure. Terms representing orientations, such as upper, lower, top, bottom and the like mentioned in the present disclosure are merely for illustrating relative positions between components, and not for limitation of specific assembly orientation of the components in the present disclosure. As shown in FIGS. 2-9 , an embodiment of the present disclosure provides a magnetic latching relay with a parallel type magnetic circuit, including a magnetic circuit portion 1 , a movable spring portion 2 , a fixed spring portion 3 and a base 4 . Wherein the magnetic circuit portion 1 includes an iron core 11 , an armature 12 , an iron yoke 13 , a permanent magnet 14 , a magnetic conductor member 15 , a coil rack 16 and an enameled wire 17 . The movable spring portion 2 includes a movable spring sheet 21 and a movable contact point 22 . The fixed spring portion 3 includes a fixed spring sheet 31 and a fixed contact point 32 . As shown in FIGS. 2 and 3 , the iron yoke 13 is L shaped, formed by a first yoke 131 parallel to the iron core and a second yoke 132 perpendicular to the iron core. An upper end of the first yoke 131 forms a hinge portion of the iron yoke 13 (a “hinge portion” refers to a contact portion of the iron yoke contacting with the armature rotating around the iron yoke). The armature 12 can rotate around the hinge portion of the iron yoke. The enameled wire 17 is wound on the coil rack 16 , and the coil rack 16 is mounted on the base 4 . In the present embodiment, the coil rack 16 is integrally formed with the base 4 . The coil rack 16 is provided with a through hole 161 along a vertical direction. The iron core 11 is mounted in the through hole 161 of the coil rack. The iron core 11 is provided at an upper end thereof with a pole shoe 111 , and the iron core 11 is secured to the second yoke 132 at its lower end. The armature 12 is connected to the iron yoke 13 via the movable spring sheet 21 . The movable spring sheet 21 is formed with a first side 211 and a second side 212 . An elastically bendable angle is formed between the first side 211 and the second side 212 . The armature 12 can be secured to the second side 212 through a rivet. The first yoke 131 can be secured to the first side 211 through a rivet. The armature 12 is flexibly connected to the first yoke 131 via the movable spring sheet 21 . The movable contact point can be secured to an end portion of the second side 212 which extends beyond the armature 12 . The second side 212 of the movable spring sheet is secured to the armature 12 and fitted on the upper side of the pole shoe 111 of the iron core, and the armature 12 is thus mounted at the hinge portion of the iron yoke. The magnetic conductor member 15 has one end connected with the first yoke 131 , and the other end connected to the first yoke 131 via the permanent magnet 14 . A magnetic isolation recess 133 is provide between a conjunction of the first yoke 131 and the permanent magnet 14 and the first yoke 131 and the magnetic conductor member 15 . The magnetic isolation recess 133 is for increasing the magnetic resistance of the magnetic circuit, and a size of the magnetic isolation recess 133 can be adjusted to adjust balance between the setting voltage and resetting voltage of the relay. The pole shoe 111 has a side provided with a cut 112 . Combined with the magnetic isolation recess 133 , a size of the cut 112 can be adjusted to adjust the balance between the setting voltage and resetting voltage of the relay. Now the drawing only shows one magnetic isolation recess 133 , however two magnetic isolation recesses 133 can be implemented as long as a cross section area of solid portion of the first yoke 131 can be adjusted. The magnetic isolation recess 133 can be replaced with other magnetic isolation configuration, such as a pillar member or the like. In the present embodiment, the cut 112 of the pole shoe 111 is a full circular shape with one portion cut off (as shown in FIG. 9 ), the full circular shape being symmetric with respect to the central axis of the iron core. However, alternatively, the cut of the pole shoe can be a full rectangle with one portion cut off, the full rectangle being symmetric with respect to the central axis of the iron core. The cut 112 of the pole shoe 111 is disposed toward a direction in which the movable contact point and the fixed contact point are to be attracted to each other (as shown in FIG. 2 ). Thereby, a creepage distance between the iron core and the fixed spring sheet can be increased. A creepage distance is a “distance” measured along an insulated surface between two conductive components. As shown in FIGS. 3, 6 and 7 , the magnetic conductor member 15 is at one end provided with a contact surface 151 for contacting the first yoke 131 . The contact surface 151 of the magnetic conductor member is provided with one or more bosses 152 for positioning of the first yoke. The first yoke 131 is provided thereon with holes 1311 fitted with the bosses of the magnetic conductor member. The bosses 152 of the magnetic conductor member is fitted within the holes 1311 of the first yoke 131 , and secured with them via a rivet or weld. The permanent magnet 14 is secured to the other end of the magnetic conductor member 15 . The magnetic conductor member is provided at the other end with bosses 153 for securing the permanent magnet. FIGS. 10-13 are schematic circuit diagrams of the relay when the relay is respectively powered off, powered with a setting voltage, when the coil is powered with a resetting voltage. Φm1, Φm2 denote magnetic fluxes (referred to as permanent magnet fluxes, generally represented by Φm) generated by the permanent magnet 14 . The paths passed by the permanent magnet fluxes are respectively referred to as a first magnetic path A 1 and a second magnetic path A 2 . Φc1, Φc2 denote magnetic fluxes (referred to as control magnet fluxes, generally represented by Φc) generated by current in the coil, and the path passed by the control magnet fluxes is referred to as a third magnetic path A 3 . Wherein, Φc1 is a magnetic flux generated by current of the coil under a setting voltage, and Φc2 is a magnetic flux generated by current of the coil under a resetting voltage. δ2 denotes an operation air gap, and F2 denotes an electromagnetic attraction force (generally represented by F) applied on the armature at the air gap δ2. The magnetic circuit has two stable states, that is, the armature 12 being at the setting position or at the resetting position. When the armature 12 is in the resetting state (the armature 12 is at an opened position, and the coil is not supplied with current) as shown in FIG. 10 , due to the effects of the magnetic conductor member 15 and the magnetic isolation recess 133 , the magnetic flux generated by the permanent magnet 14 passes through paths of the first magnetic path A 1 and the second magnetic path A 2 as shown in the figure. The magnetic fluxes denoted by Φm1 and Φm2 are parallel. On the second magnetic path A 2 , due to the influence of the air gap δ2, Φm2 has a small effect. Therefore, at this time, the armature 12 is subject to a weak electromagnetic attraction force F2 under the effect of Φm2, which is smaller than a counter force F1 applied by the movable spring sheet 21 on the armature 12 , that is, F1>F2. Then, under the counter action of the counter force of the movable spring sheet 21 , the armature 12 can be stably maintained at the resetting position (i.e. the opened position). Due to the effects of the magnetic conductor member 15 and the magnetic isolation recess 133 , the magnetic flux generated by the permanent magnet 14 are divided into magnetic fluxes Φm1 and Φm2 of two paths, and the magnitudes of the magnetic fluxes Φm1 and Φm2 can be adjusted. Thereby, it can solve the problem in the series-type magnetic circuit, there is only one path which cannot be adjusted, and the permanent magnet in the resetting position will keep a large attraction force to the armature and reduce the pressure on the contact points of the normal-close terminal and weaken the load capability of the fixed closed terminal and the product relay has a poor resistance against impact and vibration. As shown in FIG. 11 , when a resetting pulse voltage with a certain width is applied on the coil of the relay, a control magnetic flux Φc1 generated by the coil of the relay has a direction as shown by a third magnetic path A 3 in FIG. 11 . At this time, the magnetic flux Φc1 generated by the coil and the magnetic flux Φm2 generated by the permanent magnet 14 have the same direction (as shown by a second magnetic path A 2 in FIG. 11 ). This increases a composite magnetic flux at the air gap δ2. Therefore, the armature 12 is subject an increased electromagnetic attraction force F2 due to the effect of the composite magnetic flux of Φc1 and Φm2. When the electromagnetic attraction force F2 subjected by the armature 12 is larger than the counter force F1 applied by the movable spring sheet 21 on the armature 12 , the armature 12 will complete an action moving from the resetting position to the setting position under the composite force of F2 and F1. Afterwards, after the operation current of the coil is powered off, the electromagnetic attraction force F2 generated by the magnetic flux Φm2 of the permanent magnet 14 is larger than the counter force F1 applied by the movable spring sheet 21 on the armature 12 . Then, the armature 12 will be stably maintained in the setting position, as shown in FIG. 12 . When the relay is at the setting position as shown in FIG. 12 , a resetting pulse voltage (opposite to the setting voltage) with a certain width is applied to the coil of the relay, a control magnetic flux Φc2 generated by the coil of the relay has a direction as shown in FIG. 13 . At this time, the magnetic flux Φc2 generated by the coil and the magnetic flux Φm2 generated by the permanent magnet 14 have opposite directions (as shown by the second magnetic path A 2 and the third magnetic path A 3 in FIG. 13 ). Thereby, the magnetic flux Φm2 generated by the permanent magnet 14 is counteracted. Therefore, at this time, electromagnetic attraction force F2 subjected by the armature 12 is decreased due to the effects of Φc2 and Φm2. When the electromagnetic attraction force F2 subjected by the armature 12 is smaller than the counter force F1 applied by the movable spring sheet 21 on the armature 12 , the armature 12 will complete an action moving from the setting position to the resetting position under the composite force of F2 and F1, and return to the resetting position as shown in FIG. 10 . FIG. 12 shows magnetic fluxes of the magnetic circuit when the armature is at the setting position and the coil is powered off. The permanent magnet 14 has two paths of magnetic fluxes Φm1 and Φm2. The total flux of the permanent magnet 14 (Φmtotal)=Φm1+Φm2. By adjusting the size of the magnetic isolation recess 133 , a magnetic conduction cross sectional area 1331 at either side of the magnetic isolation recess 133 of the yoke (as shown in FIG. 5 ) changes and thus a magnetic resistance of the first magnetic path A 1 changes, to form a changed first magnetic fluxe Φm1. Since the total flux(Φmtotal) is substantially constant, and Φm2=(Φmtotal)−Φm1, when (Φm1 changes, Φm2 will change too (in an opposite direction of value variation). When Φm2 changes, the electromagnetic attraction force F2 generated by the permanent magnet 14 through the second magnetic path A 2 , which attracts the armature 12 on the pole shoe of the iron core, will change. That is, the retention force to keep the armature 102 against the pole shoe of the iron core changes, to solve the problem that it is hard to reset in the series-type magnetic circuit. Due to the effect of the magnetic conductor member 15 and the magnetic isolation recess 133 , the magnetic flux generated by the permanent magnet 14 is divided into two paths Φm1 and Φm2, and the magnitudes of Φm1 and Φm2 can be adjusted, to solve the problem that in the series-type magnetic circuit, there is there is only one path which cannot be adjusted, causing difficulty in resetting. When the coil of the relay is applied with a resetting pulse voltage (opposite to the setting voltage) with a certain width, the magnetic flux Φc2 generated by the coil will be counteracted by the magnetic flux Φm2 generated by the permanent magnet 14 . When the composite magnetic flux (Φm2−Φc2) is reduced to a degree that the electromagnetic attraction force F2 generated by composite magnetic flux to the armature 12 is smaller than the counter force F1 applied by the movable spring sheet 21 on the armature 12 , the armature 12 will complete an action moving from the setting position to the resetting position under the composite force of F2 and F1. As discussed above, since the size of the magnetic isolation recess 133 can be provided differently, to form a different Φm2. While the electromagnetic attraction force F2 is generated by the composite magnetic flux (Φm2-Φc2), therefore, under a different Φm2, to reduce the electromagnetic attraction force F2 to a value smaller than the counter force F1, the value of Φc2 should be changed. Since Φc2 is generated by applying a voltage on the coil, changing the size of the magnetic isolation recess 133 will change the magnitude of Φm2, and in turn, change the magnitude of the resetting voltage for resetting the armature. In the magnetic circuit of the present invention, in order to ensure a certain strength of the components, the magnetic conduction cross sectional area 1331 (as shown in FIG. 5 ) at either side of the magnetic isolation recess 133 of the yoke cannot be reduced infinitely. Therefore, Φm2 cannot be too large, and generally a small resetting voltage can be applied to obtain an electromagnetic attraction force F2, as generated by the composite magnetic flux (Φm2-Φc2), smaller than the counter force F1, to reset the armature. For a magnetic latching relay, it is desirable to make the resetting voltage to be approximate to the setting voltage as much as possible. Therefore, in order to increase the resetting voltage, in the prevent disclosure, half of the pole shoe of the iron core is cut off (according to a magnetic circuit principle, the smaller the area of the pole shoe of the iron core is, the larger the retention force (the magnetic attraction force F2) on the armature when the armature is at the setting position is, and the larger the resetting voltage required is), so as to balance the resetting voltage and the setting voltage (to make the resetting voltage to be approximate to the setting voltage in the value) as much as possible. An embodiment regarding the coil rack 16 and the fixed spring portion 3 in the relay will be described below. As shown in FIG. 2 and FIG. 14 , the fixed spring portion 3 includes the fixed spring sheet 31 and the fixed contact point 32 fixed on the fixed spring sheet 31 . The fixed spring sheet 31 is mounted at a position which allows the movable contact point and the fixed contact point to contact each other. The coil rack 16 includes an upper terminal plate 160 , a bobbin 167 and a lower terminal plate 168 . The upper terminal plate 160 of the coil rack 16 extends to a side, and a mounting portion 162 is disposed at the side. The fixed spring sheet 31 and the fixed contact point 32 are embedded in the mounting portion 162 . The movable contact point 22 is mounted at a position in the mounting portion 162 where matches with the position of the fixed contact point 32 (as shown in FIGS. 15-17 ). At least one shielding wall 163 , 164 is provided on the coil rack 16 and between the though hole 161 and the mounting portion 162 . The shielding wall 163 , 164 is formed as one piece with the coil rack 16 , to separate the pole shoe 11 at the through hole of the coil rack and the fixed spring sheet 31 at the mounting portion. In the present embodiment, as shown in FIG. 14 and FIG. 18 , there are two shielding walls 163 and 164 . A groove 165 is formed between the shielding walls 163 and 164 to collect spatters of the contact points. Wherein one shielding wall 163 is disposed close to the through hole 161 , and corresponding to the armature 12 of the movable spring sheet. The height of the shielding wall 163 is not lower than the bottom of the armature 12 when the relay is reset, in order to prevent the armature 12 from moving to the direction where the movable contact point contacts the fixed contact point. There can be provided one shielding wall. When there is only one shielding wall, the shielding wall is disposed close to the through hole, and corresponding to the armature of the movable spring sheet. The height of the shielding wall is not lower than the bottom of the armature when the relay is reset, in order to prevent the armature from moving to the direction where the movable contact point contacts the fixed contact point. A cut 112 is provided at a side of the pole shoe 111 where close to the fixed spring sheet 31 . Thus, the creepage distance between the pole shoe and the fixed spring sheet is increased by a distance of the cut 112 . Thereby, the creepage distance between the pole shoe of the iron core and the fixed spring sheet can be increased. Also referring to FIGS. 15-17 , shielding walls 163 and 164 are provided on the coil rack and between the fixed spring sheet 31 and the iron core 11 . After the movable contact point and the fixed contact point are burned, metal spatters of the movable contact point and the fixed contact point can be blocked by the shielding wall, to prevent the metal spatters from drifting from the contact points to the iron core. The groove 165 formed between the two shielding walls and a region 166 between the shielding wall 164 and the fixed contact point 32 can also be configured to collect the metal spatters of the contact points. Thereby, the creepage distance between the movable contact point and the fixed contact point as well as the dielectric Strength can be improved, and it can effectively prevent electrical accidents caused by unwanted conduction of the movable contact point and the fixed contact point due to accumulation of metal spatters of the contact points. The shielding wall 163 is disposed close to the through hole 161 , and corresponding to the armature 12 which is secured to the movable spring sheet. The height of the shielding wall 163 is not lower than the bottom of the armature 12 when the relay is reset. When the relay is subject to an impact in a length direction, the armature 12 will move toward the contact points. Due to the presence of the shielding wall 163 , the armature 12 is limited in the length direction. Thus, the armature 12 and the movable contact point 22 will not displace from normal positions due to the impact, significantly improving the impact resistance of the relay. The above configuration can expand the application range of the relay. As shown in FIGS. 19-23 , an embodiment of the present disclosure provides a coil rack of a double-coil relay. One end of the bobbin 167 is connected to the upper terminal plate 160 , the other end of the bobbin 167 is connected to the lower terminal plate 168 . A first pin 51 , a second pin 52 and a third pin 53 are respectively mounted on the lower terminal plate 168 . The lower terminal plate 168 can be integrated with the base 4 . A groove 1684 is provided at an inner side of the lower terminal plate 168 between the bobbin 167 and the second pin 52 , to guide the enameled wire. One end of the groove 1684 can be connected to the bobbin 167 , and the other end of the groove can lead to the second pin 52 . An inclined plate 1681 is provided at an inner side of the lower terminal plate 168 , and located between the bobbin 167 and the second pin 52 . The inclined plate 1681 is gradually inclined in a direction from the bobbin to the second pin. A boss 1682 extending from the bobbin to the second pin is provided in the middle of the inclined plate 1681 . That is, the boss 1682 is provided on the inclined plate 1681 , and the boss 1682 is a boss with a flat surface. A support wall 1683 is provided at a side of the inclined plate 1681 . The support wall 1683 is also provided on the inclined plate 1681 , and an upper surface of the support wall 1683 is also flat. The groove 1684 for guiding the enameled wire is surrounded and thus formed by the support wall 1683 and the boss 1682 . The bottom of the groove 1684 is an inclined plate. The height of the boss 1682 is the same as the height of the support wall 1683 . However, the height of the boss 1682 can be different from the height of the support wall 1683 . A first cover plate 1685 which can press and seize the enameled wire is mounted at the inner side of the lower terminal plate 168 and between the first pin 51 and the bobbin 167 . That is, the first cover plate 1685 is provided at the inner side of the lower terminal plate 168 , and located between the bobbin 167 and the first pin 51 . In the present embodiment, the upper surface of the first cover plate 1685 , the upper surface of the boss 1682 and the upper surface of the support wall 1683 are in the same horizontal plane. However, the upper surface of the first cover plate 1685 can also be disposed as higher than the upper surface of the boss 1682 and the upper surface of the support wall 1683 . A second cover plate 1686 which can press and seize the enameled wire is mounted at the inner side of the lower terminal plate 168 and between the third pin 53 and the bobbin 167 . That is, the second cover plate 1686 is provided at the inner side of the lower terminal plate 168 , and located between the bobbin 167 and the third pin 53 . In the present embodiment, the upper surface of the second cover plate 1686 , the upper surface of the boss 1682 and the upper surface of the support wall 1683 are in the same horizontal plane. However, the upper surface of the second cover plate 1686 can also be disposed as higher than the upper surface of the boss 1682 and the upper surface of the support wall 1683 . As shown in FIGS. 20-23 , the present embodiment provides a coil rack of a double-coil relay. To wind the enameled wire, the enameled wire are firstly wound from inner circles. After the enameled wire 17 is firstly wound on the first pin 51 , the enameled wire 17 passes below the first cover plate 1685 . After the enameled wire 17 is wound on the bobbin 167 anticlockwise for a required number of circles, the enameled wire 17 passes through the groove 1684 and leads to the second pin 52 . After the enameled wire 17 is wound on the second pin 52 , winding of the inner circles of the enameled wire 17 is completed. In winding of the outer circles, after the enameled wire 17 is wound on the second pin 52 , a first circle 171 of the enameled wire passes through the groove 1684 and leads to the bobbin 167 . After the enameled wire is wound on the bobbin 167 clockwise for a required number of circles, the last circle 172 of the enameled wire passes through the boss 1682 , the support wall 1683 and leads to the below part of the second cover plate 1686 . After the enameled wire passes through the below part of the second cover plate 1686 , and is wound on the third pin 53 , the winding of the outer circles is completed. The boss 1682 and the support wall 1683 form the groove 1684 which can guide the enameled wire; the bottom of the groove is an inclined plate; one end of the groove is connected to the bobbin; and the other end of the groove leads to the second pin. Thereby, in winding the first circle 171 of the outer circles of the enameled wire, the enameled wire is placed on the inclined plate 1681 . In winding the last circle 172 of the outer circles of the enameled wire, due to the effect of the boss 1682 and the support wall 1683 , the last circle 172 of the enameled wire can be held up, to form an air gap 173 between the first circle 171 of the enameled wire and the last circle 172 of the enameled wire, thus avoiding an unfavorable situation of the first circle and the last circle being directly placed together in winding the out circles. The above is an embodiment of the coil rack 16 , and is not exclusively applied to the above magnetic latching relay with a paralleltype magnetic circuit. The coil rack 16 can also be applied in other types of relays by those skilled in the art. Although the present disclosure has been described with reference to some exemplary embodiments, it should be understood that the terms are not restrictive, but illustrative and exemplary. The present disclosure can be embodied in various forms without departing from the spirit or essence thereof. Therefore, it can be understood that the above embodiment is not limited to the above details, but should be interpreted broadly within the spirit and scope defined by the appending claims. In this regard, all alterations and modifications falling within the claims or their equivalent scope should be covered by the appending claims.

A magnetic latching relay of a parallel type magnetic circuit, forming two parallel permanent magnetic circuits on the permanent magnetic circuit of a relay; one of the permanent magnetic circuits is used to provide adequate attraction to an armature, so that permanent magnetic attraction can achieve a balance of applied forces with the counter-force provided by a movable spring, so as to realize relay bistability or state transition more stably.

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority of U.S. Provisional Application No. 60/216,797, entitled “INTERACTIVE DATA TRANSMISSION SYSTEM,” filed on Jul. 7, 2000, which is hereby incorporated by reference for all purposes. This application is related to U.S. application Ser. No. 09/698,701 filed on the same day, and entitled “INTERACTIVE DATA TRANSMISSION SYSTEM.” BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to real-time data transmission across a network. More particularly, the present invention relates to real-time transmission of data and interactive modification of the data transmitted across a network in response to a request received from a network device over the network. 2. Description of Related Art A popular pasttime in today's entertainment-oriented society is watching movies. In fact, many movie fanatics have acquired elaborate home entertainment systems solely for this purpose. However, for those individuals who decide to spend their Saturday night at home with a movie, there a limited number of options available to them. Traditionally, movie goers who prefer to watch movies in the privacy of their own homes rent videos from a local video rental store. However, the video rental process is a time-consuming one, requiring the movie viewer to travel from his or her home merely to obtain the desired video. Of course, even with the obvious disadvantages associated with the video rental process, many still find this desirable since they can watch the movie as many times as they want, and they may pause, rewind, fast forward, and re-start the movie at their own convenience. In view of the disadvantages associated with the conventional video rental process, pay-per-view is a viable option, particularly in hotels which often do not offer video rental services to its guests. Through the pay-per-view option, it is possible to select a video as well as view the video from the privacy of home or a hotel room. However, the movie choices typically offered to movie viewers by such cable providers are limited. Moreover, the pay-per-view option does not offer the advantages of a standard VCR. More particularly, the pay-per-view option does not allow a user to pause, rewind, fast forward, or re-start a movie once it has started. In addition, the available viewing times are typically set and therefore cannot be selected by a user. Physical tapes are also used for a variety of purposes other than viewing movies. For instance, in Asian countries, karaoke is a popular pastime. A traditional karaoke business is commonly run with a central control room connected to multiple listening stations. The control room contains a machine associated with each listening station to enable a desired tape to be played and routed to the listening station (e.g., via a coaxial cable). When a karaoke participant in one of the listening stations requests a particular karaoke song, the appropriate tape is physically inserted into the machine connected to the listening station. The karaoke tape is then played and routed to the listening station connected to this machine. The existing karaoke model is undesirable in a variety of ways. Since a machine capable of playing karaoke tapes is required for each listening station, the existing karaoke system often requires numerous machines. Since these machines are not automated, it is necessary to employ personnel that will be available to operate the machines. Due to the expense associated with acquiring and maintaining numerous karaoke machines and associated personnel, a traditional karaoke business is far from inexpensive to operate. In addition, it is typically necessary to maintain multiple copies of songs that are popularly requested in order to be able to fulfill the same song request when it is received from more than one listening station. Moreover, since multiple copies are often retained for these popular selections, the cost of maintaining an adequate inventory as well as storage space to store these copies increases the cost of such a karaoke business. In addition, the quality of a physical medium such as a video tape deteriorates over time. Moreover, since the karaoke tapes must be loaded and unloaded by humans, this type of system is susceptible to human error. As a result, the incorrect tape may be loaded or there may be a substantial delay between songs while the personnel are locating or changing the tapes. Thus, it is impossible for a karaoke participant to predict the time that a selected song will start. Similarly, it is impossible to predict the delay between songs that are loaded consecutively into the karaoke machine. It is also important to note that the karaoke singers in the listening stations do not have access do the machine associated with their private listening station. Thus, once a karaoke tape has been inserted, karaoke participants cannot interactively control their individual karaoke experience. In view of the above, it would be desirable if a system could offer the interactive nature of a VCR without the limitations and conveniences associated with a VCR. In addition, it would be beneficial if a user were provided a wide range of choices previously unavailable to a VCR or pay-per-view user. SUMMARY The present invention enables data to be transmitted over a network from a server to a client device such as a set-top box. This may be accomplished via a single local server as well as via multiple staged servers, such as from a central server via the local server. For instance, the central server may be associated with a web site on the Internet. In addition, once initiated, data flow may be modified and controlled interactively by the user. Moreover, a file may be loaded from the central server to a memory associated with the local server. This loading process may be performed in combination with data transmission upon initiation by a user (e.g., via a web browser) or by the local server when a requested file is not accessible to the local server. Alternatively, it may be desirable to load a file independently from the data transmission process. In accordance with one aspect of the invention, a first network device such as a set-top box may interactively control data flow from a second network device such as a server to the first network device. A control command indicating a desired modification to the flow of data from the second network device to the first network device is received at the first network device. The first network device sends a control command to the second network device. When the second network device receives the control command, the second network device modifies the flow of data from the second network device to the first network device in response to the control command. The first network device then receives a modified flow of data from the second network device to the first network. This process may similarly be performed across multiple staged servers rather than by a single local server. Modification to the flow of data may be accomplished by modifying a data stream in a variety of ways. For instance, modification may include initiating transmission of a data stream, pausing transmission of a data stream, advancing transmission by a single frame, modifying the speed of transmission of data, and modifying the source of the data being transmitted (e.g., file and/or file location). Such a modification to the flow of data between network devices may be initiated by a user via an input device such as a mouse, keyboard, or remote control device. In accordance with another aspect of the invention, a user may select one or more files from which data is to be transmitted over a network from a network device such as a server to another device such as a set-top box. Each of the files may include video data and audio data as well as other digital data. For instance, each file may include a movie or a karaoke video. The user may select via the set-top box one or more of a plurality of files associated with the server. In addition, the user may specify an order of transmission of the selected files. Information identifying the selected files as well as the specified order of transmission may then be sent from the set-top box to the server. Data stored in these files may then be transmitted from the server to the set-top box in the order of transmission. In accordance with another aspect of the invention, the present invention enables transmission of data to be billed within a multiple site system such as a hotel. More particularly, it is possible to bill a guest each time a movie or karaoke song is played (i.e., transmitted from the local server). Moreover, the hotel may wish to bill the guest an additional amount when the requested selection is transmitted from the central server over the Internet to the guest's hotel room (e.g., when the user accesses the central server via a web browser). Of course, it may be desirable to bill a guest once (e.g., when the associated file is loaded from the central server to the local server), allowing the guest to view the selection multiple times. BRIEF DESCRIPTION OF THE DRAWINGS The invention, together with further advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which: FIG. 1 is a block diagram illustrating an exemplary system in which the present invention may be implemented in accordance with an embodiment of the invention. FIG. 2 is a block diagram illustrating an exemplary set-top box board layout that may be used to implement the present invention. FIG. 3A is an exemplary screen shot that may be presented to a user upon start-up. FIG. 3B is an exemplary screen shot illustrating the selection of karaoke songs and/or movies to be transmitted in accordance with the present invention. FIG. 4 is an exemplary layout of a remote control that may be used to implement the present invention. FIG. 5 is a process flow diagram illustrating a method of playing a movie or karaoke selection in accordance with an embodiment of the invention. FIG. 6 is a process flow diagram illustrating a method of processing a user's voice input in accordance with an embodiment of the invention. FIG. 7 is a process flow diagram illustrating a method of pausing a movie or karaoke selection in accordance with an embodiment of the invention. FIG. 8 is a process flow diagram illustrating one method of stepping transmission of data in accordance with an embodiment of the invention. FIG. 9 is a process flow diagram illustrating one method of reducing the speed of data transmission to the set-top box in accordance with one embodiment of the invention. FIG. 10 is a process flow diagram illustrating a method of initiating or resuming the transmission of data in accordance with one embodiment of the invention. FIG. 11 is a process flow diagram illustrating a method of selecting data files to be transmitted via a menu in accordance with one embodiment of the invention. FIG. 12 is a process flow diagram illustrating one method of initiating the transmission of data associated with a next selected video in accordance with one embodiment of the invention. FIG. 13 is a process flow diagram illustrating a method of performing a seek in accordance with an embodiment of the invention. FIG. 14 is a process flow diagram illustrating one method of processing data received by the set-top box in accordance with one embodiment of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order not to unnecessarily obscure the present invention. With the recent advancement of digital technology, the way information flows and data are exchanged have taken a new direction. With the aid of video compression and decompression technology, digitized audio and video data can now be transmitted live across cities, states, and countries. Moreover, network bandwidth continues to increase through the introduction of fast Ethernet, cable modem, Digital Subscriber Line (DSL), variations of DSL (xDSL), and Gigabit Ethernet. DSL service enables the transmission of data at rates up to 6.1 megabits (millions of bits) per second, enabling continuous transmission of motion video, audio, and even 3-D effects. Accordingly, real-time video transmission which requires high bandwidth is now feasible. Through the use of the present invention, files such as movies and karaoke videos may be downloaded to a local server and streamed to one or more client devices (e.g., set-top boxes). In addition, interactive control of the streamed data is made available through the set-top boxes. Accordingly, the present invention provides the traditional advantages of a conventional video recorder without the restrictions or limitations of a video recorder. FIG. 1 is a block diagram illustrating an exemplary system in which the present invention may be implemented in accordance with an embodiment of the invention. The present invention is implemented in a network such as a local area network (LAN), which may be further coupled to a wide area network (WAN) such as the Internet. Within the network, one or more local servers 102 are used as the video-streaming server. Moreover, the local server(s) 102 may also be used as the content storage server that is capable of storing a plurality of files. One or more associated file servers 104 are used for user account management, content management, billing information, web server, firewall, and all other non-streaming related services. In addition, an equivalent central file server may be established at the central site which monitors and communicates with all the remote file servers. In order to decrease the costs associated with the local server 102 and limit the number of files available for transmission to each client, it may be preferable to use a suitable memory for storing approximately twenty files (e.g., karaoke files or movie files). However, this configuration is merely exemplary and a memory with a greater capacity may be implemented. These files may be supplied initially as well as downloaded from another server on the network, as well as from the Internet. The local server 102 is adapted for being coupled (e.g., via an Ethernet switch 106 ) to a plurality of devices 108 (e.g., set-top boxes) that are each configured to transmit a control command to the local server 102 to control the initiation and flow of data associated with a particular file to the requesting device 108 . In addition, each of the devices 108 is capable of providing video and audio signals to associated monitors or televisions 110 when they are received from the local server 102 . Through each device 108 , a client may initiate the transmission of data associated with a specified file via the local server 102 . In addition, once transmission of data is initiated, it may be desirable to interactively control the transmission of data from the local server 102 . When the requested file is not available to the local server 102 , the local server may access a central server 112 over the Internet via an Internet Service Provider (ISP) 114 . The central server 112 preferably has a vast data store of files in an associated memory. Alternatively, the client may independently download a requested file from the central server 112 via a web browser independently of transmission of the associated data to the client. For instance, when the user wants to watch a video that is not available on the local server, the user may access the central server and select one of a plurality of listed videos by clicking on the desired title(s). The central server 112 may then send the file to the local server 102 for storage in the file server 104 and/or transmission to a requesting client. It is important to note that each client device 108 and the local server 102 preferably perform authentication prior to establishing a communication link. When a file is transmitted from the central server 112 to a client via the local server 102 , the transmission and interactive control of the transmitted data may be performed in a manner to enable real-time streaming and therefore instantaneous access to the data by a requesting client. Alternatively, there may be a small or considerable delay, depending upon the transmission medium that is used. For instance, the transmission medium used to transmit data from the central server 112 to the local server 102 , and from the local server 102 to each device 108 may include a traditional transmission medium such as a cable modem connection. In a WAN setting, bandwidth cannot be guaranteed at a sustainable rate to support real-time broad-band video streaming. Thus, it is important to note that the benefit of a the local server 102 in a LAN setting is to provide sustainable bandwidth to guarantee uninterrupted real-time video streaming. Traditional phone service transmits an analog signal which is converted into digital information by a modem. However, the maximum amount of data that may be received using an ordinary modem is currently approximately 56 Kbps. In contrast, with various xDSL technologies, it is possible to receive data at rates of well over one million bits per second (Mbps), enabling continuous transmission of motion video, audio, and 3-D effects. For example, current ADSL standards contemplate data receive rates on the order of 6 Mbps. VDSL proposals contemplate data receive rates on the order of 25 or 50 Mbps. Thus, the delay involved in transmission of the requested data may be minimized through the use of a Digital Subscriber Line (DSL) or variations of DSL (xDSL). As a result, video quality is improved. Moreover, since multiple devices 108 may be coupled to the central server 112 through a single Digital Subscriber Line via the local server 102 , each client need not individually obtain DSL service. In this manner, the cost to the consumer is considerably reduced while enabling the consumer to interactively control data transmission via the central server 112 with approximately instantaneous access. The present invention may be used by a business such as a hotel to enable multiple rooms to access a local server maintained by the hotel. Since the local server is maintained by the hotel, the hotel may wish to bill a guest each time a movie or karaoke song is played (i.e., transmitted from the local server 102 to a client device 108 ). Moreover, the hotel may wish to bill the guest an additional amount when the requested selection is transmitted from the central server over the Internet to the guest's hotel room (e.g., when the user accesses the central server via a web browser). Of course, it may be desirable to bill a guest once (e.g., when the associated file is loaded from the central server to the local server) while allowing the guest to view the selection multiple times. Billing information may be obtained in a variety of ways. For instance, billing information associated with the hotel room may be automatically obtained. As another example, billing information such as credit card information may be obtained from the user upon selection of a video. As yet another example, a smart card reader may be provided to enable the user to charge room services to his or her smart card. As described above with reference to FIG. 1 , multiple client devices 108 may be coupled to a single local server 102 . In accordance with one embodiment of the invention, a client device 108 may be implemented in the form of a set-top box. A set-top box is a device that enables a television set to become a user interface to the Internet and also enables a television set to receive and decode digital television broadcasts. More particularly, a set-top box is used by television viewers to receive digital broadcasts via an analog television set. A set-top box typically includes a Web browser stored in a memory in the set-top box, enabling a television user to access the Internet. In addition, a typical digital set-top box contains one or more microprocessors for running the operating system and for parsing an MPEG transport stream. A set-top box also includes RAM, an MPEG decoder chip as well as other chips for audio decoding and processing. In addition, a set-top box may contain a hard drive for storing recorded television broadcasts, for downloaded software, and for other applications. Similarly, a DVD drive may be used to enable the set-top box to access a variety of files. FIG. 2 is a block diagram illustrating an exemplary set-top box board layout that may be used to implement the present invention. In one embodiment, the set-top box board implements a standard Ethernet implementation and therefore includes a 10BaseT Interface 202 , an Ethernet controller 204 , an EEPROM 206 for storing an IP address associated with the set-top box board, and SRAMs 208 , 210 for storing data obtained from the network (e.g., Internet). In addition, the set-top box includes a CPU 212 for running the operating system and for parsing an MPEG data stream. In addition, a flash EPROM 214 may store software for drivers and other instructions necessary to implement the present invention. Moreover, this client software that is programmed into the flash EPROM 214 may be updated through the local server at any time for feature enhancement. System memory 216 (e.g., DRAM) is available for use by the CPU. In addition, EPLD 218 is adapted for routing signals among components, thereby providing the appropriate combinational logic for the set-top box. MPEG decoder 220 is provided for decompressing video and audio data received in the compressed data received by the set-top box. DRAM chips 222 , 224 , 226 , 228 , and 230 are provided for storing video data for the MPEG decoder 220 . After the video and audio data is decompressed by the MPEG decoder 220 , the decompressed audio and video signals are processed separately. The decompressed video signal is then sent from the MPEG decoder 220 to a video encoder 242 to convert the digital video signal to an analog signal. The analog video signal is then output at a video input/output 244 . The decompressed audio signal is sent from the MPEG decoder 220 to digital-to-analog converter 236 and output via stereo output 238 and therefore through an amplifier (not shown). In accordance with one embodiment, the set-top box includes karaoke capabilities. Thus, in addition to the data (e.g., karaoke file) received from the network, one or more microphone inputs 231 and 232 are provided to enable users to sing along with a karaoke selection. In the embodiment shown, two microphone inputs are supported, although it should be appreciated that any desired number of microphones may be provided. When a karaoke singer sings into a microphone, the audio signal is processed by an analog to digital converter 233 . The digital audio signal is then sent to a karaoke audio processor 234 . For instance, the karaoke audio processor 234 may be a digital karaoke audio processor such as model MED25102 available from Medianix Semiconductor, Inc., located at 100 View Street, Mountain View, Calif. 94041. The digital audio signal processed by the karaoke processor 234 is then sent to digital-to-analog converter 236 and output via stereo output 238 . In addition, a DRAM chip 240 is available for storing audio data for the karaoke processor 234 . A standard audio input 246 is also provided. In addition, an infra-red interface controller (not shown) may be provided to enable communication with a remote control device. In accordance with one embodiment, the set-top box is capable of switching between NTSC and PAL signals for world-wide adoption and compatibility. In addition, to implement a karaoke system, user interfaces in different languages may be provided by the set-top box. Similarly, files encoded with sound tracks in multiple languages may be provided at the local server to enable a sound track in a particular language to be selected at the set-top box. FIG. 3A is an exemplary screen shot that may be presented to a user upon start-up. As shown, an initial screen 302 may be displayed which indicates one or more selections which may be input by a user. For instance, at start-up, a default selection type 304 may be presented to the user. More particularly, the selection type 304 of a file to be transmitted may be, for example, “karaoke” or “movie”. Thus, the default selection type 304 may be “karaoke”, as shown. In addition, the user may indicate a particular selection 306 associated with the selection type 304 . As shown, a number, title, or other mechanism may be used to identify each selection. FIG. 3B is an exemplary screen shot illustrating the selection of karaoke songs and/or movies to be transmitted in accordance with the present invention. Once the user has entered one or more selections, a TV screen or monitor 308 after all selections are entered is displayed. Thus, the selection type 310 may be “movie” or “karaoke”, as shown. In addition, each selection 312 is identified numerically in accordance with a pre-selected set of selections available to the user. For instance, a manual may be provided to the user identifying the selections available to the user. As described above, the user sends control commands to the set-top box indicating desired modifications to the flow of data to the set-top box. In accordance with one embodiment, these control commands are sent to the set-top box via an infra-red remote control. FIG. 4 is an exemplary layout of a remote control that may be used to implement the present invention. A TV/VIDEO key 402 enables a user to toggle between a television and video mode. In addition, a NEXT key 404 stops the current video (e.g., movie or karaoke) and starts the next video selected. An ENTER key 406 enables a user to enter a number of key strokes. In addition, an NTSC/PAL key 408 enables a user to switch between NTSC and PAL mode, as described above. A RESET key 410 reboots the set-top box. A VIEW/MENU key 412 enables a user to view a video after all karaoke or movie selections are entered. During video play, when the VIEW/MENU key 412 is toggled, a menu screen is displayed to enable the user to add or edit the video selections. The user may then toggle the VIEW/MENU key 412 an additional time to start playing the current video selection. Number keys 0 – 9 413 – 430 may be used to identify video titles. Arrow keys 432 – 438 move the cursor up, down, right or left to enable a user to enter or modify selections. Various control keys are provided to initiate or modify the flow of data to the set-top box. When a PLAY key 440 is pressed, a selected video (e.g., movie or karaoke selection) is played at normal speed from either a PAUSE, STEP, or SLOW mode, each of which will be described in further detail below. In addition, in accordance with one embodiment, a percent video played indicator is displayed on the screen to indicate the amount of the video that remains to be transmitted. When a SLOW key 442 is pressed, the video speed is slowed (e.g., to one-half normal speed). The PLAY key 440 may then be pressed to resume to normal speed. Similarly, when a PAUSE key 444 is pressed, the video is paused until the PLAY key 440 , the SLOW key 442 , or a STEP key 446 is pressed. Once the STEP key 446 is pressed, the video is advanced by one frame at a time. Rather than viewing the entire video, the user may wish to view only specific portions of the video. When a SEEK key 448 is pressed during video play, the user may select a percentage of the video file to jump to. The video then jumps to that location and begins to play starting from that location. The seek location may be any location in the video file. Accordingly, the seek function may operate in forward or reverse. In addition to video control keys described above, karaoke control keys are provided to enable the user to modify the audio signal associated with the karaoke music and/or the user's voice. The key functions may be implemented through the use of a conventional karaoke audio processor such as karaoke audio processor MED25102 available from Medianix. Various keys are provided on the remote control to implement various functions available in a karaoke processor. For instance, KEY− 450 decreases the key of the music, KEY+ 452 increases the key of the music, KEY N 454 returns the key of the music to neutral, VOL+ 456 increases the microphone volume, VOL− 458 decreases the microphone volume, ECHO+ 460 increases microphone echo, and ECHO− 462 decreases microphone echo. When FADER 464 key is pressed, the vocal portion of the music is silenced. PITCH 466 changes the pitch of the karaoke singer's voice that is received through the microphone by shifting the pitch one semi-note with each depression. HARMONY 468 adds a pitch-shifted and a non pitch-shifted microphone signal to create the sound of two vocalists. MUTE 470 mutes the associated microphone. As described above with reference to FIG. 4 , a remote control may enable a user to modify the flow of data to a set-top box. However, other input devices may be used. For instance, such input devices include, but are not limited to, a keyboard or a mouse. Through the use of the present invention, data may be transmitted from a particular network device to a requesting network device. In accordance with one embodiment, data is transmitted to a set-top box from a local server. Of course, when a particular file is not directly accessible by the local server, the file may be downloaded from a central server (e.g., to a file server associated with the local server). In addition, data may be transmitted from the central server via the local server. The downloading and/or transmission from the central server to the local server may be initiated by the user (e.g., via a web browser) or by the local server when the file cannot be directly accessed by the local server. Once data flow associated with a file is initiated, the data flow may be modified through the sending of various control commands by the user (e.g., via an infra-red remote control). In accordance with one embodiment, data flow from the local server may be modified by the user. The flow of data and modification of the data flow from the local server will be described in further detail below with reference to FIG. 5 through FIG. 14 . However, it will be understood that the flow of data and modification of the data flow may also be performed via the central server. FIG. 5 is a process flow diagram illustrating a method of playing a movie or karaoke selection in accordance with an embodiment of the invention. When the set-top box is turned on at block 502 , a menu is displayed at block 504 . For instance, a screen such as that illustrated in FIG. 3A may be displayed to enable a user to enter one or more karaoke or movie selections as shown in FIG. 3B . The user enters one or more selections at block 506 to indicate those movies, karaoke selections or other video files to be transmitted to the set-top box. The user then selects a control command at block 508 to initiate, terminate or otherwise modify the flow of data to the set-top box. Thus, the control command generally indicates a desired modification of the flow of data to the set-top box. More particularly, this may be accomplished by pressing a key on a remote control such as that described above with reference to FIG. 4 . For instance, the user may select the VIEW command in order to view a selected video. When the control command (e.g., view command) is received by the set-top box at block 510 , the set-top box deciphers the infra red control signal and sends the control command to a CPU of the set-top box at block 512 . The set-top box then sends the control command to the local server at block 514 . The local server receives the control command at block 516 . In addition, the local server may receive a signal indicating a current video selection. The local server then sends a compressed data stream over a network to the set-top box at block 518 . More particularly, the compressed data stream may include audio, video and other digital data. The set-top box then processes the data received from the local server at block 520 . One method of processing the data by the set-top box is described in further detail below with reference to FIG. 14 . In accordance with one embodiment, the user may initiate and modify the transmission of karaoke data from a server to the set-top box. Thus, a first audio signal is received by the set-top box from a server and processed, as will be described below with reference to FIG. 14 . In addition, the user may sing along with the karaoke selection through a microphone, creating a second audio signal. FIG. 6 is a process flow diagram illustrating a method of processing a user's voice input in accordance with an embodiment of the invention. More particularly, when a user sings through a microphone connected to the set-top box at block 600 , the audio signal is processed by an analog to digital converter at block 602 . In addition, the user may select an audio control command as shown at block 604 via a karaoke control key as described above with reference to FIG. 4 to modify the audio signal that is ultimately produced by the set-top box. For instance, the user may wish to adjust the volume or pitch. The singer's voice is then processed by the karaoke processor at block 606 to modify the second audio signal. This modified second audio signal is then sent to a digital to analog converter at block 608 . The resulting analog audio signal is then sent to an amplifier at block 610 . The flow of data to the set-top box may be modified in a variety of ways. As described above with reference to FIG. 4 , the flow of data may be modified in a variety of ways. For instance, the user may wish to pause a video, or press a remote control key such as STEP, SLOW, PLAY, MENU, NEXT, or SEEK. Exemplary process flow diagrams illustrating such possible modifications to the flow of data to a set-top box will be described in further detail below with reference to FIG. 7 through FIG. 13 . When a user wishes to pause the transmission of data to the set-top box, the user may press the PAUSE button on the remote control. FIG. 7 is a process flow diagram illustrating a method of pausing a movie or karaoke selection in accordance with an embodiment of the invention. As shown, when a user selects a pause control command at block 702 , the set-top box deciphers the infra-red control at block 704 . The pause control command is then sent to a CPU of the set-top box at block 706 . The set-top box sends the pause control command to the local server at block 708 . In response, as shown at block 710 , the local server stops sending data to the set-top box until further instruction. A user may press the STEP key when he or she wishes to step the transmission of data (e.g., by a single frame). FIG. 8 is a process flow diagram illustrating one method of stepping transmission of data in accordance with an embodiment of the invention. As shown at block 802 , a user may select the step control command through pressing the STEP key on a remote control. When the infra red signal is received by the set-top box, the set-top box deciphers the infra red signal at block 804 and sends a step control command to a CPU of the set-top box at block 806 . The set-top box (e.g., CPU) then transmits this step control command to the local server at block 808 . In response, the local server advances the appropriate video by a frame by sending data associated with that frame to the set-top box at block 810 . The set-top box then processes the data received from the local server at block 812 , as will be described in further detail below with reference to FIG. 14 . A user may similarly wish to modify the speed of transmission of data to the set-top box over the network. For instance, the user may wish to reduce as well as increase the speed of data transmission. FIG. 9 is a process flow diagram illustrating one method of reducing the speed of data transmission to the set-top box in accordance with one embodiment of the invention. When a user wishes to slow the speed of data transmission, the user may press a SLOW key on a remote control as shown at block 902 , as described above with reference to FIG. 4 . The set-top box deciphers the infra red control at block 904 and a slow control command indicating that the data transmission is to be slowed is sent to a CPU of the set-top box at block 906 . The set-top box then sends the slow control command to the local server at block 908 . In response to the control command, the local server reduces the speed with which data (e.g., frames) are sent to the set-top box at block 910 . The local server then continues to send compressed data over the network to the set-top box at block 912 . The set-top box then processes the data received from the local server at block 914 , which will be described in further detail below with reference to FIG. 14 . The user may also wish to initiate the transmission of data over the network to the set-top box (e.g., from a pause mode). Alternatively, the user may wish to resume transmission of data to a normal speed from a step or slow mode. FIG. 10 is a process flow diagram illustrating a method of initiating or resuming the transmission of data in accordance with one embodiment of the invention. As shown at block 1002 , the user may select the play control command at block 1002 . This may be accomplished through pressing the PLAY key on a remote control such as that illustrated in FIG. 4 . For instance, the PLAY key may be pressed from the pause, step, or slow mode. The set-top box then deciphers the infra red control at block 1004 and a play control command indicating that initiation of the transmission of data is requested is sent to a CPU of the set-top box at block 1006 . The set-top box then sends the play control command to the local server at block 1008 . The local server then initiates the transmission of data at block 1010 . More particularly, the local server may initiate the transmission of data or simply return to normal speed with which data is sent to the set-top box. The local server continues to send compressed data over the network to the set-top box at block 1012 . In addition, in accordance with one embodiment, the local server sends a percentage value indicating a percent of the file that has been transmitted (e.g., percent of a movie that has been played over the network). The set-top box processes the data it receives from the local server at block 1014 , as will be described in further detail below with reference to FIG. 14 . The set-top box further displays the percent of the selection that has been transmitted to the set-top box and therefore played for the user at block 1016 . As described above, the data may be associated with any file, such as a movie or karaoke selection. The user may wish to edit his or her selections that have been previously entered via a screen such as that illustrated in FIG. 3A and FIG. 3B . In this manner, the user may specify via the set-top box an order of transmission of one or more files. The files may be of varying types, such as those storing movies or karaoke videos. It is important to note that the files being selected are not stored locally at the set-top box, but identify files stored in association with a remotely located server on the network. FIG. 11 is a process flow diagram illustrating a method of selecting data files to be transmitted via a menu in accordance with one embodiment of the invention. As shown, the user may select a menu control command at block 1102 which sends an infra red signal to the set-top box. The set-top box deciphers the infra red control at block 1104 and sends this menu control command to a CPU of the set-top box at block 1106 . The set-top box sends this menu control command over the network to the local server at block 1108 . The local server then stops sending compressed data over the network to the set-top box at block 1110 . For instance, the local server may stop sending data until a VIEW/MENU key on a remote control such as that illustrated in FIG. 4 is toggled by the user. The set-top box then displays a menu of selections at block 1112 . As one example, the menu may present the user with a number of possible files (e.g., movie or karaoke) to be transmitted to the set-top box. As another example, the menu may simply be a screen such as that presented in FIG. 3A which may enable a user to enter as well as modify his or her selections as illustrated in FIG. 3B . When presented with this menu, the user may add as well as edit the menu selections that are displayed at block 1114 . As one example, the user may have be presented with a screen illustrating a single previously entered selection. The user may then enter or select additional selections up to a maximum number of permissible selections. As another example, the menu may present the user with a number of selections previously selected by the user. The user may then modify one or more of these selections. When the user decides to view one or more of his selections, the view control command may be selected by again toggling the VIEW/MENU key at block 1116 . The set-top box deciphers the infra-red control at block 1118 and a view control command is sent to a CPU of the set-top box at block 1120 . The set-top box sends the view control command over the network to the local server at block 1122 . For instance, the view control command may identify one or more files to be transmitted over the network. In addition, the view control command may also indicate the order of transmission of those files. Of course, the view control command may also designate a starting point from which compressed data is to be transmitted. The starting point may indicate a specific file as well as a location (e.g., percentage) within that file. The local server then resumes sending compressed data over the network to the set-top box at block 1124 . The set-top box then processes the data it receives at block 1126 , which will be described in further detail below with reference to FIG. 14 . Rather than allowing all selections to play consecutively, the user may wish to terminate a current video and start the next selected video. FIG. 12 is a process flow diagram illustrating one method of initiating the transmission of data associated with a next selected video in accordance with one embodiment of the invention. When the user wishes to stop the transmission of data associated with a first video and start the transmission of data associated with a second video, the user may select the next control command at block 1202 by pressing the NEXT key on a remote control such as that illustrated in FIG. 4 . The set-top box deciphers the infra red control at block 1204 . A next control command indicating that a next video is selected is then sent to a CPU of the set-top box at block 1206 . The set-top box sends the next control command to the local server indicating that the next video is selected as shown at block 1208 . For instance, the next control command may directly or indirectly identify a currently selected video. At block 1210 the local server stops sending compressed data associated with the previous selection over the network to the set-top box. The local server then sends compressed data associated with the current selection over the network to the set-top box at block 1212 . The set-top box then processes the data it receives from the local server at block 1214 . One method of processing the compressed data will be described in further detail below with reference to FIG. 14 . When a user wishes to initiate transmission of data from a particular location in a file, the user may press the SEEK key of a remote control such as that illustrated in FIG. 4 . FIG. 13 is a process flow diagram illustrating a method of performing a seek in accordance with an embodiment of the invention. As shown at block 1302 the user may select the seek control command by pressing the SEEK key of a remote control at block 1302 . In addition, the user indicates a location in the video file from which data transmission is desired at block 1304 . In accordance with one embodiment, the user selects a percentage of a video file that has been transmitted. The set-top box deciphers the infra red control at block 1306 and the corresponding seek control command indicating the desired percentage is sent to a CPU of the set-top box at block 1308 . In accordance with one embodiment, the starting point in the file from which data is to be transmitted is calculated by the set-top box. More particularly, when the file is initially selected, the local server sends information associated with the file such as the size of the file to the set-top box. For instance, when an MPEG file is transmitted, file information is transmitted in the initial packets that are transmitted. The set-top box uses the size of the file and the percentage to determine a starting point in the file at block 1310 . The set-top box then sends an indicator of the desired file location to the local server at block 1312 . Alternatively, the calculation of the starting point may be performed by the local server. In accordance with this embodiment, the set-top box sends the seek control command indicating the desired percentage over the network to the local server at block 1310 . When the local server receives the seek control command, the local server uses the size of the file and the percentage to determine a starting point in the file at block 1312 . The local server then “jumps” to this starting point in the file at block 1314 and initiates the transmission of compressed data from the starting point over the network to the set-top box at block 1316 . The set-top box then processes the data it receives from the local server at block 1318 , which will be described in further detail below with reference to FIG. 14 . As described above, when the set-top box receives compressed data sent over the network, the set-top box processes this data. FIG. 14 is a process flow diagram illustrating one method of processing data received by the set-top box in accordance with one embodiment of the invention. A variety of commands sent by the set-top box result in compressed video data being sent to a requesting client (e.g., set-top box). When the client sends a request to a server asking the server to send compressed video data to the client, the server splits the associated compressed video data file (or portion thereof) into multiple packets and sends the packets to the client. As shown at block 1402 the set-top box receives the compressed video data from the local server. An MPEG decoder chip then decompresses video and audio data in the compressed data at block 1404 . The decompressed video signal is then sent to a video encoder to convert the digital signal to an analog signal at block 1406 . The resulting analog signal is then output to a television or monitor at block 1408 . The data received by the set-top box may be stored for future use. However, it may be desirable to delete the data once it is provided by the set-top box to the user. In this manner, a video may be displayed in real-time onto a television screen. In addition to the decompressed video data, the decompressed audio data is also processed by the set-top box. More particularly, in accordance with the karaoke embodiment, the decompressed audio signal is sent to the karaoke processor at block 1410 . The processed audio signal is then sent to a digital to analog converter at block 1412 . The resulting analog audio signal is then sent to an amplifier at block 1414 . When data is transmitted from the central server to the set-top box via a local server, the local server may store a copy of this data (e.g., in an associated file server). Alternatively, it may be desirable to erase this copy once the data is transmitted to a requesting set-top box. The present invention may be used in a variety of environments. For instance, the above-described system may be configured as a networked karaoke system to enable a plurality of rooms to access karaoke songs concurrently without the intervention of a human operator. The present invention may also be used to provide hotels a cost-effective solution to deliver movies to hotel guests. Moreover, it may also be useful in hospitals to enable bed-ridden patients to watch movies or surf the Internet. Schools may also implement the present invention within a campus local area network to transmit video-taped lectures or other presentations. Additionally, long trips in a confined seat takes a toll on passengers in a common carrier such as an airplane, cruise ship, train or bus. Thus, the present invention may allow each passenger to watch and control a movie he or she is interested in throughout the entire trip. It may also be desirable to implement the present invention within an apartment complex to enable the system as well as system costs to be shared by each residential unit. Additionally, the present invention may be deployed as a video kiosk in airports, train stations, hotel lobbies, department stores, conventions, or museums for information, catalog or advertisement purposes. The emergence of the Internet has created a world-wide data network. As Internet traffic grows steadily, the data highway's bandwidth increases accordingly. This presents a major opportunity for a new class of dedicated communication devices that will allow users to conduct communication (e.g., via voice and video data) through the data network. This information exchange has evolved from text-based to graphics-based to content-rich, video-based communications capable of providing a multitude of services. Accordingly, the present invention may be implemented in a device or web browser to provide interactive, real-time, high-bandwidth services to a user using the Internet. As described above, the present invention enables a client device such as a set-top box to receive data streams such as video streams that are transported over a network from a video server. In addition, the set-top box might output information to the network in the course of performing the above-described method steps. Such information may be received from and outputted to the network, for example, in the form of a computer data signal embodied in a carrier wave. The network may also be a wireless network. Through the use of the present invention, video, audio, and karaoke functionality are integrated in a single system capable of interfacing to a standard television. Since the present invention is implemented in a set-top box, it is compact and portable. Moreover, since a computer system is not required, the present invention may be manufactured at a relatively low cost to the consumer. Although illustrative embodiments and applications of this invention are shown and described herein, many variations and modifications are possible which remain within the concept, scope, and spirit of the invention, and these variations would become clear to those of ordinary skill in the art after perusal of this application. For instance, the present invention is described as transmitting data from a local server within the context of a digital television receiver. However, the present invention may be used in other contexts, such as through transmitting data from another server (e.g., central server) via the local server. For instance, the present invention may permit access to a central server on the Internet. Similarly, the present invention may be implemented across a plurality of staged servers, enabling information to be transmitted across the Internet. Moreover, the above described process blocks are illustrative only. Therefore, the present invention may be performed using alternate process blocks as well as alternate data structures. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Methods and apparatus for use in a network including a local server coupled to a central server, the local server being coupled to a plurality of network devices, for interactively controlling from one of the plurality of network devices a flow of audio visual data from the central server to the network device, comprising obtaining a control command at the network device, the control command indicating a desired modification to the flow of the audio visual data from the central server to the network device. The control command is sent from the network device to the central server via the local server. A modified flow of the audio visual data is then received from the central server at the network device in response to the control command.

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a wavelength conversion device composed of a semiconductor laser device and a nonlinear optical element having a planar optical waveguide, which are mounted on a substrate in an integrated manner. [0003] 2. Related Background Art [0004] In order to realize a high-density optical disk and a high-definition display, small short-wavelength light sources generating a laser beam in a blue range through violet range are desired. Techniques for obtaining a laser beam in this wavelength range include a second harmonic-wave generation method (hereinafter referred to as “SHG”) that employs a wavelength conversion device using a planar optical waveguide according to a quasi-phase-matching method, by which a wavelength of a semiconductor laser can be converted from 850 nm into 425 nm. [0005] To miniaturize a short-wavelength light source according to this method, it is effective to mount a wavelength conversion device and a semiconductor laser device on a substrate in an integrated manner. [0006] [0006]FIG. 15 shows one example of these small short-wavelength light sources, which is a wavelength conversion device disclosed in JP 2000-284135 A. [0007] A semiconductor laser device 306 and a planar optical waveguide device 305 are mounted on a silicon substrate 300 in an integrated manner. The planar optical waveguide device 305 functions as a wavelength conversion device structured by forming a proton exchange planar optical waveguide 304 and a diffraction grating (not illustrated) with periodic domain inverted regions formed therein on an Mg doped LiNbO 3 substrate 302 . In addition, on the silicon substrate 300 , electrodes 307 electrically connected to the semiconductor laser device 306 are formed, and alignment keys 301 are formed at positions 10 μm away from the planar optical waveguide 304 . On each side of the planar optical waveguide 304 , alignment keys 303 are formed using a film made of the same material (e.g., Ta) and having the same thickness as those of the alignment keys 301 . Further, alignment keys 308 are formed on the semiconductor laser device 306 as well. [0008] Here, the semiconductor laser device 306 is a Distributed Bragg Reflector (hereinafter, referred to as “DBR”) type semiconductor laser device. As shown in FIG. 15, the electrodes 307 are connected to each of a gain region and a wavelength control region, i.e., a DBR region (not illustrated) of the semiconductor laser device 306 . [0009] The semiconductor laser device 306 and the planar optical waveguide device 305 are mounted onto the silicon substrate 300 in such a manner that a laser beam emitted from the semiconductor laser device 306 is guided through the optical waveguide 304 in the planar optical waveguide device 305 , and the alignment keys 308 , 303 , and 301 are arranged at their predetermined positions. In this wavelength conversion device, a center line M 1 -M 2 of the silicon substrate 300 , a center line M 5 -M 6 of the semiconductor laser device 306 , and a center line M 3 -M 4 of the planar optical waveguide device 305 approximately coincide with one another. [0010] In the future, to miniaturize an optical information processing system employing an optical disk and a display still more than present ones, an optical pick up unit included in an optical disk or the like needs to be made small. To this end, it becomes effective to make a wavelength conversion device smaller. [0011] Meanwhile, when electrically driving such a wavelength conversion device, an oscillation wavelength of a laser beam emitted from the semiconductor laser device 306 needs to be controlled so as to maximize a conversion efficiency of the laser beam by the SHG. [0012] In the wavelength conversion device shown in FIG. 15, by controlling a current applied to the electrode connected to the DBR region, among the electrodes 307 , a refractive index of the DBR region is varied so as to change a Bragg wavelength, whereby the oscillation wavelength is controlled. In this wavelength conversion device, however, a phase of the emitted laser beam cannot be controlled, because the semiconductor laser device 306 consists of only two regions, i.e., the gain region and the DBR region. Due to such a constraint, if a Bragg wavelength in the DBR region is varied by the passage of the electric current, then a so-called mode hoping would occur, where the oscillation wavelength changes discontinuously. In this case, it becomes difficult to control the oscillation wavelength, which might interfere with the operation of the device significantly. SUMMARY OF THE INVENTION [0013] Therefore, with the foregoing in mind, it is an object of the present invention to provide a small short-wavelength conversion device composed of a semiconductor laser device and an optical waveguide device, which are mounted on a substrate in an integrated manner. [0014] To fulfill the above-stated object, a wavelength conversion device according to an embodiment of the present invention, which converts a wavelength by second harmonic-wave generation and generates a laser beam, includes: a substrate having a plurality of electrodes; a semiconductor laser device mounted on the substrate and electrically connected to the plurality of electrodes; and a nonlinear optical element having an optical waveguide for guiding a laser beam emitted from the semiconductor laser device and for converting a wavelength of the laser beam. Here, the nonlinear optical element is mounted on the substrate in such a manner that the optical waveguide in the nonlinear optical element is located away from the center line of the substrate. [0015] To fulfill the above-stated object, a wavelength conversion device according to another embodiment of the present invention, which converts a wavelength by second harmonic-wave generation and generates a laser beam, includes: a substrate having a plurality of electrodes; a semiconductor laser device electrically connected to the plurality of electrodes; and a nonlinear optical element having an optical waveguide for guiding a laser beam emitted from the semiconductor laser device and for converting a wavelength of the laser beam. Here, the semiconductor laser device, the optical waveguide of the nonlinear optical element, and the plurality of electrodes are on approximately one line on the substrate. [0016] It is another object of the present invention to provide a wavelength conversion device by which an oscillation wavelength of a laser beam emitted from a semiconductor laser device can be controlled with stability. [0017] To fulfill the above-stated object, a wavelength conversion device according to an embodiment of the present invention, which converts a wavelength by second harmonic-wave generation and generates a laser beam, includes: a substrate having a plurality of electrodes; a semiconductor laser device mounted on the substrate and including three regions of a gain region, a phase control region, and a wavelength control region; and a nonlinear optical element mounted on the substrate and for converting a wavelength of a laser beam emitted from the semiconductor laser device. Here, the plurality of electrodes include a first electrode group formed corresponding to the three regions and a second electrode group for carrying out wire-bonding with an external power source, the three regions of the semiconductor laser device are connected electrically to the respective electrodes in the first electrode group, and the first electrode group further is connected to the respective electrodes in the second electrode group via wires, and a wire among the wires, which is connected between the phase control region and the wavelength control region of the semiconductor laser device, has a portion functioning as a resistor. BRIEF DESCRIPTION OF THE DRAWINGS [0018] [0018]FIG. 1 is a plan view of a wavelength conversion device according to Embodiment 1; [0019] [0019]FIG. 2 is a plan view of a wavelength conversion device according to Embodiment 2; [0020] [0020]FIG. 3 is a plan view of a wavelength conversion device according to Embodiment 3; [0021] [0021]FIG. 4 is a plan view of a wavelength conversion device according to Embodiment 4; [0022] [0022]FIG. 5 is a plan view of a wavelength conversion device according to Embodiment 5; [0023] [0023]FIG. 6 is a plan view of a wavelength conversion device according to Embodiment 6; [0024] [0024]FIG. 7 is a plan view of a wavelength conversion device according to Embodiment 7; [0025] [0025]FIG. 8 is a plan view of a wavelength conversion device according to Embodiment 8; [0026] [0026]FIG. 9 is a plan view of a wavelength conversion device according to Embodiment 9; [0027] [0027]FIG. 10 is a plan view of a wavelength conversion device according to Embodiment 10; [0028] [0028]FIG. 11 is a plan view of a wavelength conversion device according to Embodiment 11; [0029] [0029]FIG. 12 is a plan view of a wavelength conversion device according to Embodiment 12; [0030] [0030]FIG. 13 is a graph showing the relationship among oscillation longitudinal mode orders, and amount of current fed into a phase control region and a DBR region; [0031] [0031]FIG. 14 is a circuit diagram showing a state where the phase control region and the DBR region of the semiconductor laser device are driven at the same voltage; and [0032] [0032]FIG. 15 is a plan view of a wavelength conversion device according to the prior art. DETAILED DESCRIPTION OF THE INVENTION [0033] The following describes embodiments of the present invention, with reference to the drawings. [0034] [Embodiment 1] [0035] [0035]FIG. 1 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate (3 mm in width, 15 mm in length), electrodes 1 , 2 , and 3 are formed by patterning, and a DBR laser element 4 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 7 (2.8 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 6 denotes an optical waveguide, and 8 denotes a diffraction grating formed in the optical waveguide 6 . Line 100 is a center line of the optical waveguide 6 . Line M 1 a -M 2 a is a center line of the width direction of the silicon substrate 5 , and line M 5 a -M 6 a is a center line of the width direction of the nonlinear optical element 7 . Hereinafter, in the wavelength conversion devices according to the present invention, the direction perpendicular to the optical waveguide is referred to as the width direction, while the direction parallel to the optical waveguide is referred to as the longitudinal direction. [0036] The DBR laser element 4 is made up of three regions including a gain region that adjusts an output power of a laser beam emitted therefrom, a phase control region that changes a phase of the laser beam, and a DBR region that feeds back a laser beam with an oscillation wavelength into a cavity. Note here that these regions referred to in this embodiment or later in this specification have the functions as stated above. [0037] With respect to these three regions, electrodes that are electrically isolated from one another are formed (not illustrated). The DBR laser element 4 is mounted on the silicon substrate 5 in a junction down manner where a surface with the p-n junction faces to the side of the silicon substrate 5 , and electrodes corresponding to the gain region, the phase control region, and the DBR region are bonded to the electrodes 1 , 2 , and 3 on the silicon substrate 5 , respectively. Also, wire-bonding regions are formed in each of the electrodes for carrying out wiring with an external power source so as to electrically drive the gain region, the phase control region, and the DBR region. [0038] In this way, the gain region, the phase control region, and the DBR region of the DBR laser element 4 are connected electrically to the electrodes 1 , 2 , and 3 , respectively. In this state, by feeding an electrical signal to each of the electrodes, an oscillation wavelength of the laser beam emitted from the DBR laser element 4 can be varied. The oscillation wavelength of the laser beam emitted from the DBR laser element 4 is set at 820 nm, and the beam is oscillated in the single longitudinal mode. [0039] The nonlinear optical element 7 is made of LiNbO 3 , and the optical waveguide 6 having the diffraction grating 8 is formed therein. The nonlinear optical element 7 is fixed onto the silicon substrate 5 at a predetermined position with an adhesive such as a UV curing agent. [0040] The diffraction grating 8 is formed by inverting a polarization of LiNbO 3 crystals with the application of an external electric field. The optical waveguide 6 is positioned within 3 μm of the DBR laser element 4 so as to introduce the laser beam emitted from the DBR laser element 4 securely. [0041] When guiding the laser beam through the optical waveguide 6 , a second harmonic-wave generated beam (hereinafter, referred to as “SHG beam”) with a wavelength of 410 nm generated in the nonlinear optical element 7 due to a diffraction by the diffraction grating 8 and the laser beam with an oscillation wavelength of 820 nm are quasi-phase matched. Thereby, an SHG beam having a high output power can be obtained. In addition, by controlling the oscillation wavelength of the laser beam emitted from the DBR laser element 4 , a conversion efficiency into the SHG beam can be improved. [0042] In this embodiment, as shown in FIG. 1, the nonlinear optical element 7 is mounted on the silicon substrate 5 in such a manner that the center line 100 of its optical waveguide 6 is 1.0 mm away from the center line M 1 a -M 2 a of the silicon substrate 5 . In this way, in this embodiment, the optical waveguide 6 does not necessarily need to be formed on the center line M 5 a -M 6 a of the nonlinear optical element 7 . [0043] In addition, the nonlinear optical element 7 is mounted so that the center line M 1 a -M 2 a of the silicon substrate 5 coincides with the center line M 5 a -M 6 a of the nonlinear optical element 7 in FIG. 1. However, these center lines do not necessarily coincide with each other. [0044] Furthermore, the end of the optical waveguide 6 at the side of the nonlinear optical element 7 where the SHG beam is emitted is located at least 5 μm beyond the edge of the silicon substrate 5 . This construction prevents the SHG beam from being reflected from the silicon substrate 5 and scattered, and therefore a favorable image can be obtained in the far field for the SHG beam emitted from the nonlinear optical element 7 . [0045] According to this embodiment, since the nonlinear optical element 7 is mounted on the substrate in such a manner that its optical waveguide 6 is located away from the center line M 1 a -M 2 a of the silicon substrate 5 , the width of the wavelength conversion device can be narrowed to 5 μmm or less, and therefore a small wavelength conversion device having approximately the same size as the nonlinear optical element 7 can be realized. [0046] [Embodiment 2] [0047] [0047]FIG. 2 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate 5 (2 mm in width, 6 mm in length), electrodes 1 , 2 , and 3 are formed by patterning, and a DBR laser element 4 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 7 (2.8 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 6 denotes an optical waveguide, and 8 denotes a diffraction grating formed in the optical waveguide 6 . Line 100 is a center line of the optical waveguide 6 . Line M 1 b -M 2 b is a center line of the width direction of the silicon substrate 5 , and line M 5 b -M 6 b is a center line of the width direction of the nonlinear optical element 7 . In this way, the construction of the wavelength conversion device in this embodiment is similar to that of the wavelength conversion device according to Embodiment 1, except that the silicon substrate 5 is miniaturized so that a length of a region where the DBR laser element 4 is mounted on the silicon substrate 5 is 3 mm along the longitudinal direction of the silicon substrate 5 , and the nonlinear optical element 7 is mounted on the substrate so that the center line 100 of its optical wavelength 6 is 0.7 mm away from the center line of the silicon substrate 5 . That is, in this embodiment also, the nonlinear optical element 7 is positioned within 3 μm of the DBR laser element 4 so as to introduce the laser beam emitted from the DBR laser element 4 securely, and the end of the optical waveguide 6 at the side where the SHG beam is emitted is located at least 5 μm beyond the edge of the silicon substrate 5 . Therefore, their explanations will be omitted. [0048] According to this embodiment, the same effects as in Embodiment 1 can be obtained. In addition, by reducing the length of the silicon substrate 5 , the region where the nonlinear optical element 7 is mounted on the silicon substrate 5 is narrowed. Therefore, distortion generated due to the contact between the nonlinear optical element 7 and the silicon substrate 5 can be reduced, and a conversion efficiency from the laser beam emitted from the DBR laser element 4 into the SHG beam can be improved. [0049] [Embodiment 3] [0050] [0050]FIG. 3 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate 5 (3.0 mm in width, 12 mm in length), electrodes 9 , 10 , and 11 are formed by patterning, and a DBR laser element 4 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 7 (2.8 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 6 denotes an optical waveguide, and 8 denotes a diffraction grating formed in the optical waveguide 6 . Line 100 is a center line of the optical waveguide 6 . Line M 1 c -M 2 c is a center line of the width direction of the silicon substrate 5 , and line M 5 c -M 6 c is a center line of the width direction of the nonlinear optical element 7 . [0051] The DBR laser element 4 is made up of three regions including a gain region, a phase control region, and a DBR region. [0052] With respect to these three regions, electrodes that are electrically isolated from one another are formed (not illustrated). The DBR laser element 4 is mounted on the silicon substrate 5 in a junction down manner where a surface with the p-n junction faces to the side of the silicon substrate 5 , and electrodes corresponding to the gain region, the phase control region, and the DBR region are bonded to regions 9 b, 10 b , and 11 b of the electrodes 9 , 10 , and 11 , respectively. [0053] Also, wire-bonding regions 9 a , 10 a , and 11 a are formed in each of the electrodes 9 , 10 , and 11 for carrying out wiring with an external power source so as to electrically drive the gain region, the phase control region, and the DBR region of the DBR laser element 4 . Here, widths of portions formed between these wire-bonding regions and regions 9 b , 10 b , and ll b (hereinafter, refered to as “connection regions”, which are connected to the respective electrodes formed in the three regions in the DBR laser element 4 ) are narrower than those of the wire-bonding regions and the connection regions. In this way, by partially narrowing the width of each of the electrodes formed on the silicon substrate 5 , the parasitic capacitance of these electrodes can be reduced. [0054] As stated above, the construction of the wavelength conversion device according to this embodiment is similar to that of the wavelength conversion device according to Embodiment 1, except that the width of each electrode formed on the silicon substrate 5 is narrowed in part, and the nonlinear optical element 7 is mounted on the substrate so that the center line 100 of its optical wavelength 6 is 1.0 mm away from the center line of the silicon substrate 5 . That is, in this embodiment also, the nonlinear optical element 7 is positioned within 3 μm of the DBR laser element 4 , and the end of the optical waveguide 6 at the side where the SHG beam is emitted is located at least 5 μm beyond the edge of the silicon substrate 5 . Therefore, their explanations will be omitted. [0055] According to this embodiment, the same effects as in Embodiment 1 can be obtained. In addition, by partially narrowing the width of each electrode formed on the silicon substrate 5 , the parasitic capacitance of these electrodes can be reduced, and therefore an electrical modulation frequency of the DBR laser element 4 can be increased. [0056] [Embodiment 4] [0057] [0057]FIG. 4 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate 5 (2.0 mm in width, 6.0 mm in length), electrodes 9 , 10 , and 11 are formed by patterning, and a DBR laser element 4 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 7 (2.8 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 6 denotes an optical waveguide, and 8 denotes a diffraction grating formed in the optical waveguide 6 . Line 100 is a center line of the optical waveguide 6 . Line M 1 d -M 2 d is a center line of the width direction of the silicon substrate 5 , and line M 5 d -M 6 d is a center line of the width direction of the nonlinear optical element 7 . [0058] The DBR laser element 4 is made up of three regions including a gain region, a phase control region, and a DBR region. [0059] With respect to these three regions, electrodes that are electrically isolated from one another are formed (not illustrated). The DBR laser element 4 is mounted on the silicon substrate 5 in a junction down manner where a surface with the p-n junction faces to the side of the silicon substrate 5 , and electrodes corresponding to the gain region, the phase control region, and the DBR region are bonded to regions 9 b , 10 b , and 11 b of the electrodes 9 , 10 , and 11 , respectively. [0060] Also, wire-bonding regions 9 a , 10 a , and 11 a are formed in each of the electrodes 9 , 10 , and 11 for carrying out wiring with an external power source so as to electrically drive the gain region, the phase control region, and the DBR region of the DBR laser element 4 . Here, widths of portions formed between these wire-bonding regions and regions 9 b , 10 b , and 11 b (hereinafter, referred to as “connection regions”, which are connected to the respective electrodes formed in the three regions n the DBR laser element 4 ) are narrower than those of the wire-bonding regions and the connection regions. In this way, by partially narrowing the width of each of the electrodes formed on the silicon substrate 5 , the parasitic capacitance of these electrodes can be reduced. As stated above, the construction of the wavelength conversion device according to this embodiment is similar to that of the wavelength conversion device according to Embodiment 1, except that the silicon substrate 5 is miniaturized so that a length of a region where the DBR laser element 4 is mounted on the silicon substrate 5 is 3 mm along the longitudinal direction of the silicon substrate 5 , the nonlinear optical element 7 is mounted on the substrate so that the center line 100 of its optical wavelength 6 is 0.7 mm away from the center line of the silicon substrate 5 , and the width of each electrode formed on the silicon substrate 5 is narrowed in part. That is, in this embodiment also, the nonlinear optical element 7 is positioned within 3 μm of the DBR laser element 4 , and the end of the optical waveguide 6 at the side where the SHG beam is emitted is located at least 5 μm beyond the edge of the silicon substrate 5 . Therefore, their explanations will be omitted. [0061] According to this embodiment, the same effects as in Embodiment 1 can be obtained. In addition, by reducing the length of the silicon substrate 5 , the region where the optical element 7 is mounted on the silicon substrate 5 is narrowed. Therefore, distortion generated in the optical waveguide 6 due to the contact between the nonlinear optical element 7 and the silicon substrate 5 can be reduced, and a conversion efficiency from the laser beam emitted from the DBR laser element 4 into the SHG beam can be improved. Furthermore, by partially narrowing the width of each electrode formed on the silicon substrate 5 , the parasitic capacitance of these electrodes can be reduced, and therefore an electrical modulation frequency of the DBR laser element 4 can be increased. [0062] [Embodiment 5] [0063] [0063]FIG. 5 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate 112 (3 mm in width, 15 mm in length), electrodes 101 , 102 , 103 , 104 , 105 , and 106 are formed by patterning, and a DBR laser element 107 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 115 (2.8 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 110 denotes an optical waveguide, and 111 denotes a diffraction grating formed in the optical waveguide 110 . Line 100 is a center line of the optical waveguide 110 . [0064] The DBR laser element 107 is made up of three regions including a gain region, a phase control region, and a DBR region. [0065] With respect to these three regions, electrodes that are electrically isolated from one another are formed (not illustrated). The DBR laser element 107 is mounted on the silicon substrate 112 in a junction down manner where a surface with the p-n junction faces to the side of the silicon substrate 112 , and electrodes corresponding to the gain region, the phase control region, and the DBR region are bonded to the electrodes 101 , 102 , and 103 (hereinafter called “connection electrodes”), respectively. [0066] Electrodes 104 , 105 , and 106 are wire-bonding electrodes for carrying out wiring with an external power source so as to electrically drive the gain region, the phase control region, and the DBR region, respectively. Then, these wire-bonding electrodes and the connection electrodes formed corresponding to the respective regions in the DBR laser element 107 are connected with each other by wires 13 a , 13 b , and 13 c , respectively. In this state, by feeding an electrical signal to each of the connection electrodes, an oscillation wavelength of the laser beam emitted from the DBR laser element 107 can be varied. The oscillation wavelength of the laser beam emitted from the DBR laser element 107 is set at 820 nm, and the beam is oscillated in the single longitudinal mode. [0067] The nonlinear optical element 115 is made of LiNbO 3 , and the optical waveguide 110 having the diffraction grating 111 is formed therein. The nonlinear optical element 115 is fixed onto the silicon substrate 112 at a predetermined position with an adhesive such as a UV curing agent. [0068] The diffraction grating 111 is formed by inverting a polarization of LiNbO 3 crystals with the application of an external electric field. The optical waveguide 110 is positioned within 3 μm of the DBR laser element 107 so as to introduce the laser beam emitted from the DBR laser element 107 securely. [0069] When guiding the laser beam through the optical waveguide 110 , an SHG beam with a wavelength of 410 nm generated due to a diffraction by the diffraction grating 111 and the laser beam with an oscillation wavelength of 820 nm are quasi-phase matched. Thereby, an SHG beam having a high output power can be obtained. In addition, by controlling the oscillation wavelength of the laser beam emitted from the DBR laser element 107 , a conversion efficiency from the laser beam into the SHG beam can be improved. [0070] In this embodiment, the DBR laser element 107 , the optical waveguide 110 of the nonlinear optical element 115 , and the electrodes 101 through 106 are arranged on the line 100 on the silicon substrate 112 . [0071] Furthermore, the end of the optical waveguide 110 in the nonlinear optical element 115 at the side where the SHG beam is emitted is located at least 5 μm beyond the edge of the silicon substrate 112 . This construction prevents the SHG beam from being reflected from the silicon substrate 112 and scattered, and therefore a favorable image can be obtained in the far field for the SHG beam emitted from the nonlinear optical element 115 . [0072] According to this embodiment, since the DBR laser element 107 , the optical waveguide 110 of the nonlinear optical element 115 , and the electrodes 101 through 106 are arranged on the line 100 on the silicon substrate 112 , the width of the wavelength conversion device can be narrowed to 5 mm or less, and therefore a wavelength conversion device having a width approximately the same as the width of the nonlinear optical element 115 can be obtained. [0073] [Embodiment 6] [0074] [0074]FIG. 6 is a plan view of a wavelength conversion device according to this embodiment. The construction of the wavelength conversion device according to this embodiment is similar to that of the wavelength conversion device according to Embodiment 5, except that the length of the silicon substrate 112 is made 6 mm, which is less than half the length of the silicon substrate 112 in Embodiment 5 (15 mm), and that a length of a region where the DBR laser element 107 is mounted on the silicon substrate 112 is 3 mm along the longitudinal direction of the silicon substrate 112 . That is, in this embodiment also, the nonlinear optical element 115 is positioned within 3 μm of the DBR laser element 107 . Therefore, their explanations will be omitted. [0075] According to this embodiment, the same effects as in Embodiment 5 can be obtained. In addition, by reducing the length of the silicon substrate 112 , the silicon substrate 112 can be miniaturized, and therefore the wavelength conversion device can be miniaturized and the cost can be reduced. Furthermore, by narrowing the region where the optical element 115 is mounted on the silicon substrate 112 , distortion of the optical waveguide 110 generated due to the contact between the nonlinear optical element 115 and the silicon substrate 112 can be reduced, and a conversion efficiency from the laser beam emitted from the DBR laser element 107 into the SHG beam can be improved. [0076] [Embodiment 7] [0077] [0077]FIG. 7 is a plan view of a wavelength conversion device according to this embodiment. The construction of the wavelength conversion device according to this embodiment is similar to that of the wavelength conversion device according to Embodiment 6, except that the width of the silicon substrate 112 is made to be 2.5 mm, which is narrowed by 0.5 mm versus that in Embodiment 6 (3 mm). That is, in this embodiment also, a length of a region where the DBR laser element 107 is mounted on the silicon substrate 112 is 3 mm along the longitudinal direction of the silicon substrate 112 , and the nonlinear optical element 115 is positioned within 3 μm of the DBR laser element 107 . Therefore, their explanations will be omitted. [0078] According to this embodiment, the same effects as in Embodiment 6 can be obtained. In addition, the silicon substrate 112 further can be miniaturized, and therefore the wavelength conversion device can be miniaturized and the cost can be reduced. [0079] [Embodiment 8] [0080] [0080]FIG. 8 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate 112 (3 mm in width, 15 mm in length), electrodes 101 , 102 , 103 , 104 , 105 , and 106 are formed by patterning, and a DBR laser element 107 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 115 (1.5 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 110 denotes an optical waveguide, and 111 denotes a diffraction grating formed in the optical waveguide 110 . Line 100 is a center line of the optical waveguide 110 . Line M 100 -M 200 is a center line of the width direction of the silicon substrate 112 and line M 500 -M 600 is a center line of the width direction of the nonlinear optical element 115 . [0081] In this embodiment, the DBR laser element 107 , the optical waveguide 110 of the nonlinear optical element 115 , and the electrodes 101 through 106 are arranged on the line 100 on the silicon substrate 112 , and connection wires 13 a , 13 b , and 13 c are connected to the electrodes 101 through 103 at the same side thereof so as to extend in the longitudinal direction of the silicon substrate 112 . Also, the width of the silicon substrate 112 is made to be 2 mm, which is narrowed by 0.5 mm versus that in Embodiment 7 (2.5 mm). [0082] In addition, the nonlinear optical element 115 is mounted on the silicon substrate 112 in such a manner that the center line 100 of its optical waveguide 110 is 0.5 mm away from the center line M 100 -M 200 of the silicon substrate 112 and 0.3 mm away from the center line M 500 -M 600 of the nonlinear optical element 115 . Thereby, the width of the nonlinear optical element 115 is narrowed further to 1.5 mm from 2.0 mm. [0083] In the same manner as in Embodiment 7, a length of a region where the DBR laser element 107 is mounted on the silicon substrate 112 is 3 mm along the longitudinal direction of the silicon substrate 112 , and the nonlinear optical element 115 is positioned within 3 μm of the DBR laser element 107 . [0084] According to this embodiment, the same effects as in Embodiment 7 can be obtained. In addition, with the construction where the connection wires 13 a , 13 b , and 13 c are connected to the electrodes 101 through 103 at the same side thereof on the silicon substrate 112 , and the nonlinear optical element 115 is mounted on the silicon substrate 112 in such a manner that the optical waveguide 110 is away from the center line M 100 -M 200 of the silicon substrate 112 and away from the center line of the nonlinear optical element 115 , regions where any components and wires are not formed on the silicon substrate 112 can be reduced, and the width of the silicon substrate 112 can be narrowed, and therefore a wavelength conversion device using the same can be miniaturized. [0085] [Embodiment 9] [0086] [0086]FIG. 9 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate 212 (3 mm in width, 15 mm in length), electrodes 201 , 202 , 203 , 204 , and 205 are formed by patterning, and a DBR laser element 207 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 215 (2.8 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 210 denotes an optical waveguide, and 211 denotes a diffraction grating formed in the optical waveguide 210 . Line 100 is a center line of the optical waveguide 210 . [0087] The DBR laser element 207 is made up of three regions including a gain region, a phase control region, and a DBR region. [0088] With respect to these three regions of the DBR laser element 207 , electrodes that are electrically isolated from one another are formed (not illustrated). The DBR laser element 207 is mounted on the silicon substrate 212 in a junction down manner where a surface with the p-n junction faces to the side of the silicon substrate 212 , and electrodes corresponding to the gain region, the phase control region, and the DBR region are bonded to the electrodes 201 , 202 , and 203 (connection electrodes), respectively. [0089] Electrodes 204 and 205 are wire-bonding electrodes for carrying out wiring with an external power source so as to electrically drive the gain region, the phase control region, and the DBR region, respectively. Then, these wire-bonding electrodes and the connection electrodes formed corresponding to the respective regions in the DBR laser element 207 are connected with each other by wires 214 and 213 . Here, the wire 214 is connected to the gain region, and the wire 213 is connected to the phase control region and the DBR region. The wire 214 is made of metal, and the wire 213 is made of p-type polysilicon with a resistor 213 a formed at a portion thereof. [0090] In this state, by feeding an electrical signal to each of the connection electrodes, an oscillation wavelength of the laser beam emitted from the DBR laser element 207 can be varied. By varying a voltage applied across the electrode 205 , a current fed into the gain region in the DBR laser element 207 can be controlled, and thus an output power of the laser beam can be controlled. The oscillation wavelength of the laser beam emitted from the DBR laser element 207 is set at 820 nm, and the beam is oscillated in the single longitudinal mode. [0091] The nonlinear optical element 215 is made of LiNbO 3 , and the optical waveguide 210 having the diffraction grating 211 is formed therein. The nonlinear optical element 215 is fixed onto the silicon substrate 212 at a predetermined position with an adhesive such as a UV curing agent. [0092] The diffraction grating 211 is formed by inverting a polarization of LiNbO 3 crystals with the application of an external electric field. The optical waveguide 210 is positioned within 3 μm of the DBR laser element 207 so as to introduce the laser beam emitted from the DBR laser element 207 securely. [0093] When guiding the laser beam through the optical waveguide 210 , an SHG beam with a wavelength of 410 nm generated due to a diffraction by the diffraction grating 211 and the laser beam with an oscillation wavelength of 820 nm are quasi-phase matched. Thereby, an SHG beam having a high output power can be obtained. In addition, by controlling the oscillation wavelength of the laser beam emitted from the DBR laser element 207 , a conversion efficiency from the laser beam into the SHG beam can be improved. [0094] In this embodiment, the DBR laser element 207 , the optical waveguide 210 of the nonlinear optical element 215 , and the electrodes 201 through 205 are arranged on the line 100 on the silicon substrate 212 . With this construction, the width of the wavelength conversion device can be narrowed to 5 mm or less, and a small wavelength conversion device having approximately the same width as the nonlinear optical element 215 can be realized. [0095] By providing the DBR laser element 207 with the phase control region, in addition to the gain region and the DBR region, so-called mode hopping can be prevented, and thus the oscillation wavelength can be controlled continuously. Unlike the gain region, the phase control region is a region from which gain is not obtained by the passage of electric current. In addition, the phase control region does not have a wavelength selectivity, because it is not provided with a diffraction grating as in the DBR region. When passing electric current through the phase control region, an effective refractive index in the optical waveguide within the region varies, and therefore a phase of the laser beam at a resonant state can be changed. [0096] [0096]FIG. 13 is a graph showing a relationship among oscillation longitudinal mode orders, amount of current fed into the phase control region and the DBR region in an AlGaAs class laser element. When injecting an electric current into the DBR region, the effective refractive index is increased, and the Bragg wavelength is shifted to the long wavelength side. Therefore, the oscillation longitudinal mode order mode-hops from the N-th to N−1-th, i.e., to the lower order. Meanwhile, when injecting an electric current into the phase control region, the effective refractive index is increased, and the effective cavity length is increased. Therefore, the oscillation longitudinal mode order mode-hops from the N-th to N+1-th, i.e., to the higher order. [0097] Consequently, as shown by the broken line in FIG. 13 where a ratio of the current injected into the DBR region to that into the phase control region is kept constant, when injecting an electrical current into the DBR region, the Bragg wavelength is shifted to the long wavelength side, and the oscillation wavelength whose mode gain is the highest is shifted to the long wavelength side. When injecting an electric current into the phase control region, the effective refractive index in this region is increased, and the effective resonator length is increased. Therefore, even when the oscillation wavelength shifts to the longer wavelength side, the oscillation at the same N-th longitudinal mode can be kept in the same phase state, and thus mode hopping can be prevented. [0098] [0098]FIG. 14 is a circuit diagram showing a state where resistors are connected in series to each of the phase control region 401 a and the DBR region 401 b in the semiconductor laser device 401 and the respective regions are driven with the same bias voltage applied by the power source 404 . In such a state, current injected into the phase control region and the DBR region has the relationship as represented by the following formula (1). I DBR =( R 2 +R DBR )/( R 1 +R PHASE )× I PHASE   (1) [0099] Here, I PHASE and I DBR are currents injected into the phase control region and the DBR region, respectively. R 1 and R PHASE are a value of differential resistance of the phase control region (constant value) and a value of resistance of the resistor 402 connected to the phase control region, respectively, while R 2 and RDBR are a value of differential resistance of the DBR region (constant value) and a value of resistance of the resistor 403 connected to the DBR region, respectively. [0100] Therefore, as shown by Formula (1), by varying the values of R PHASE and R DBR connected to the phase control region and the DBR region, a ratio between the current I DBR and I PHASE (i.e., (R 2 +R DBR )/(R 1 +R PHASE ), hereinafter, referred to as a ratio between currents) can be controlled. [0101] In this embodiment, as shown in FIG. 9, the resistor 213 a is formed at a portion of the wire connected between the phase control region and the DBR region in the semiconductor laser device. Assuming that the resistor 213 a has a value of resistance represented by R, the ratio between currents becomes I DBR /I PHASE =(R 2 +R)/(R 1 +R). Therefore, by adjusting the value R of the resistor 213 a so that the oscillation longitudinal mode orders does not generate mode-hopping, the oscillation wavelength of the laser beam emitted from the semiconductor laser device can be varied continuously. Note here that the value of R preferably is set within a range between 10 −3 Ω·cm and 10 6 Ω·cm. [0102] According to this embodiment, by providing a portion of the wire connected between the phase control region and the DBR region with a function as a resistor and adjusting the value of the resistor, the oscillation wavelength of the laser beam emitted from the semiconductor laser device can be controlled with stability. [0103] [Embodiment 10] [0104] [0104]FIG. 10 is a plan view of a wavelength conversion device according to this embodiment. The construction of the wavelength conversion device is similar to that of the wavelength conversion device according to Embodiment 9, except that the length of the silicon substrate 212 in the longitudinal direction is made to be 6 mm, which is a half or less of the length in Embodiment 9 (15 mm), the length of a region where the DBR laser element 207 is mounted on the silicon substrate 212 in the longitudinal direction of the silicon substrate 212 is 3 mm, and the width of the silicon substrate 212 is made to be 2 mm, which is narrowed by 1 mm from the width of the silicon substrate 212 in Embodiment 9 (3 mm). That is, in this embodiment also, the nonlinear optical element 215 is positioned within 3 μm of the DBR laser element 207 . Therefore, their explanations will be omitted. [0105] According to this embodiment, the same effects as in Embodiment 9 can be obtained. In addition, by reducing the length of the silicon substrate 212 , the silicon substrate 212 can be miniaturized, and therefore the wavelength conversion device can be miniaturized and the cost can be reduced. Furthermore, by narrowing the region where the optical element 215 is mounted on the silicon substrate 212 , distortion of the optical waveguide 210 generated due to the contact between the nonlinear optical element 215 and the silicon substrate 212 can be reduced, and a conversion efficiency from the laser beam emitted from the DBR laser element 207 into the SHG beam can be improved. [0106] [Embodiment 11] [0107] [0107]FIG. 11 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate 212 (3.2 mm in width, 11.5 mm in length), electrodes 221 , 222 , 223 , 224 , and 225 are formed by patterning, and a DBR laser element 227 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 215 (3 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 210 denotes an optical waveguide, and 211 denotes a diffraction grating formed in the optical waveguide 210 . Line 100 is a center line of the optical waveguide 210 . Line M 10 a -M 20 a is a center line of the width direction of the silicon substrate 212 and line M 50 a -M 60 a is a center line of the width direction of the nonlinear optical element 215 . [0108] The DBR laser element 227 is made up of three regions including a gain region, a phase control region, and a DBR region. [0109] With respect to these three regions, electrodes that are electrically isolated from one another are formed (not illustrated). The DBR laser element 227 is mounted on the silicon substrate 212 in a junction down manner where a surface with the p-n junction faces to the side of the silicon substrate 212 , and electrodes corresponding to the gain region, the phase control region, and the DBR region are bonded to the electrodes 221 , 222 , and 223 (connection electrodes), respectively. [0110] Electrodes 224 and 225 are wire-bonding electrodes for carrying out wiring with an external power source so as to electrically drive the gain region, the phase control region, and the DBR region, respectively. Then, a wire 214 is connected between the electrodes 221 and 224 , and a wire 213 is connected among the electrodes 222 and 223 , and 225 . The wire 214 is made of metal, and the wire 213 is made of p-type polysilicon with a resistor 213 a formed at a portion thereof. [0111] In this state, by feeding an electrical signal to each of the connection electrodes, an oscillation wavelength of the laser beam emitted from the DBR laser element 227 can be varied. By varying a voltage applied across the electrode 224 , a current fed into the gain region in the DBR laser element 227 can be controlled, and thus an output power of the laser beam can be controlled. The oscillation wavelength of the laser beam emitted from the DBR laser element 227 is set at 820 nm, and the light is oscillated in the single longitudinal mode. [0112] The nonlinear optical element 215 is made of LiNbO 3 , and the optical waveguide 210 having the diffraction grating 211 is formed therein. The nonlinear optical element 215 is fixed onto the silicon substrate 212 at a predetermined position with an adhesive such as a UV curing agent. [0113] The diffraction grating 211 is formed by inverting a polarization of LiNbO 3 crystals with the application of an external electric field. The optical waveguide 210 is positioned within 3 μm of the DBR laser element 227 so as to introduce the laser beam emitted from the DBR laser element 227 securely. [0114] When guiding the laser beam through the optical waveguide 210 , an SHG beam with a wavelength of 410 nm generated due to a diffraction by the diffraction grating 211 and the laser beam with an oscillation wavelength of 820 nm are quasi-phase matched. Thereby, an SHG beam having a high output power can be obtained. In addition, by controlling the oscillation wavelength of the laser beam emitted from the DBR laser element 227 , a conversion efficiency from the laser beam into the SHG beam can be improved. [0115] In this embodiment, as shown in FIG. 11, the nonlinear optical element 215 is mounted on the substrate in such a manner that the center line 100 of its optical waveguide 210 is located 1.0 mm away from the center line M 10 a -M 20 a of the silicon substrate 212 . In this way, the optical waveguide 210 does not necessarily need to be formed on the center line M 50 a -M 60 a of the nonlinear optical element 215 . [0116] In addition, although the nonlinear optical element is mounted on the substrate in such a manner that the center line M 10 a -M 20 a of the silicon substrate 212 coincides with the center line M 50 a -M 60 a of the nonlinear optical element 215 , these center lines do not necessarily need to be aligned. [0117] Furthermore, the end of the optical waveguide 210 at the side of the optical waveguide 210 where the SHG beam is emitted is located at least 5 μm beyond the edge of the silicon substrate 212 . This construction prevents the SHG beam from being reflected from the silicon substrate 212 and scattered, and therefore a favorable image can be obtained in the far field for the SHG beam emitted from the nonlinear optical element 215 . [0118] In this embodiment, a resistor 213 a is formed at a portion of the wire connected between the phase control region and the DBR region of the semiconductor laser device. Due to the same principle as in Embodiment 9, by controlling the value R of the resistor 213 a so that the oscillation longitudinal mode orders do not generate mode-hopping, the oscillation wavelength of the laser beam emitted from the semiconductor laser device can be varied continuously. Note here that the value of R preferably is set within a range between 10 −3 Ω·cm and 10 6 Ω·cm. [0119] According to this embodiment, by providing a portion of the wire connected between the phase control region and the DBR region with a function as a resistor and controlling the value of the resistor, the oscillation wavelength of the laser beam emitted from the semiconductor laser device can be controlled with stability. [0120] In addition, since the nonlinear optical element 215 is mounted on the substrate in such a manner that its optical waveguide 210 is located away from the center line M 10 a -M 20 a of the silicon substrate 212 , the width of the wavelength conversion device can be narrowed to 5 mm or less, and therefore a small wavelength conversion device having approximately the same size as the nonlinear optical element 215 can be realized. As a result, the silicon substrate 212 further can be miniaturized, and therefore the wavelength conversion device can be miniaturized and the cost can be reduced. [0121] [Embodiment 12] [0122] [0122]FIG. 12 is a plan view of a wavelength conversion device according to this embodiment. On a silicon substrate 212 (2.0 mm in width, 6 mm in length), electrodes 221 , 222 , 223 , 224 , and 225 are formed by patterning, and a DBR laser element 227 (0.3 mm in width, 1.2 mm in length) and a nonlinear optical element 215 (2.8 mm in width, 10 mm in length) are mounted in an integrated manner. Numeral 210 denotes an optical waveguide, and 211 denotes a diffraction grating formed in the optical waveguide 210 . Line 100 is a center line of the optical waveguide 210 . Line M 10 b -M 20 b is a center line of the width direction of the silicon substrate 212 and line M 50 b -M 60 b is a center line of the width direction of the nonlinear optical element 215 . In this way, the construction of the wavelength conversion device in this embodiment is similar to that of the wavelength conversion device according to Embodiment 11, except that the silicon substrate 212 is miniaturized so that a length of a region where the DBR laser element 227 is mounted on the silicon substrate 212 is 3 mm along the longitudinal direction of the silicon substrate 212 , and the nonlinear optical element 215 is mounted on the substrate so that the center line 100 of its optical wavelength 210 is 0.7 mm away from the center line of the silicon substrate 212 . That is, in this embodiment also, the nonlinear optical element 215 is arranged within 3 μm from the DBR laser element 227 so as to securely introduce the laser beam emitted from the DBR laser element 227 . Therefore, their explanations will be omitted. [0123] According to this embodiment, the same effects as in Embodiment 11 can be obtained. In addition, by reducing the length of the silicon substrate 212 , the region where the nonlinear optical element is mounted on the silicon substrate 212 is narrowed. Therefore, distortion generated due to the contact between the nonlinear optical element 215 and the silicon substrate 212 can be reduced, and a conversion efficiency from the laser beam emitted from the DBR laser element 227 into the SHG beam can be improved. [0124] In the above-stated embodiments, the substrate is made of silicon. However, instead of silicon, materials such as SiC or AlN may be used. With these materials, thermal dissipation of the device can be improved, the operational current of the semiconductor laser device can be decreased, and the operational temperature range of the semiconductor laser device can be broadened. Alternatively, resin such as plastic may be used. If using a resin substrate, an electrical wiring pattern can be integrated on the substrate. As a result, a more light-weight, miniaturized, and low-cost wavelength conversion device can be obtained. [0125] In the above-stated embodiments, the nonlinear optical elements are made of LiNbO 3 . Instead, materials such as LiTaO 3 , KTiOPO 4 , and KNbO 3 may be used. [0126] In the above-stated embodiments, DBR laser elements are used as the semiconductor laser device. Instead, multielectrode driven type laser elements such as a multielectrode semiconductor laser device capable of a Fabry-Perot mode oscillation, a multielectrode Distributed Feedback (abbreviated as “DFB”) type laser element, a multielectrode bistable semiconductor laser element, and a pulse laser may be used. With these elements, the time dependency of the output power of the SHG beam can be lessened. Alternatively, instead of the DBR laser element, laser elements whose wavelength can be controlled may be used. [0127] In the above-stated embodiments, the semiconductor laser devices have three regions. However, insofar as the oscillation wavelength of the laser beam emitted therefrom can be controlled adequately, semiconductor laser devices having two regions or four or more regions may be used. [0128] If optical components such as a lens, birefringence material, prism, mirror, and an optical modulator may be integrated as the integrated components, in addition to the semiconductor laser device and the nonlinear optical element, a small wavelength conversion device can be obtained. [0129] Furthermore, the wires connecting components may be integrated on the silicon substrate directly. In the case of the substrate made of silicon, instead of metal, polycrystal silicon, p-type silicon, and n-type silicon can be used as a material of the wire. [0130] The invention may be embodied in other forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limiting. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

A wavelength conversion device that converts a wavelength by second harmonic-wave generation and generates a laser beam, includes: a substrate having a plurality of electrodes; a semiconductor laser device mounted on the substrate and electrically connected to the plurality of electrodes; and a nonlinear optical element having an optical waveguide for guiding a laser beam emitted from the semiconductor laser device and for converting a wavelength of the laser beam. Here, the nonlinear optical element is mounted on the substrate so that the optical waveguide in the nonlinear optical element is located away from the center line of the substrate. Thereby, a small wavelength conversion device provided with a semiconductor laser device and a nonlinear optical element, which are mounted on the substrate in an integrated manner, can be obtained, and therefore an optical pickup unit in the optical disk employing this wavelength conversion device can be miniaturized.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a multi-purpose clamping apparatus for pressing the confronting edges or ends of two boards or other components during a gluing process. 2. Description of the Prior Art In the practice of woodwork crafting the occasion often arises where boards or other components of wood or composites or other man-made materials are to be joined together along proximate edges or ends to provide a composite frame, border or panel to be integrated into a piece of furniture or molding. For narrow slats and the like, conventional clamps and vises, having a bite sufficient to span the width of the boards or items being joined, are satisfactory to engage the opposite sides of such boards and press them firmly together at the edges to be joined. However, difficulty is encountered when the boards to be joined are collectively wider than the bite of a conventional vise. A challenge is also presented when the boards are to be joined endwise thus requiring gripping of the boards for application of compressive forces in the longitudinal direction. The challenges encountered are compounded when the boards to be joined are to project at various angles, such as 90° to one another. In practice, it is desirable to orient the components in edgewise contacting relation to secure the relative positioning so as to visually check the fit and then, if satisfactory, separate such components to space the components apart for access to the mating edges for application of glue while monitoring the relative component orientation for repeating the mating fit with the glued edges. Numerous differed devices have been proposed in effort to solve the problems encountered in joining wide boards together laterally, lay boards together endwise, and other boards together at various uncommon angles. One such mechanical device for clamping together of the confronting edges of boards during a gluing process incorporates a vise-like bar-clamp having two jaws at opposite ends of a bar that draw together boards placed in-between as the jaws are drawn together in a screw-like action. These vise-like clamping devices must more or less vary in size in direct relation to the composite span of the boards to be joined. Where large boards, such as plywood or particle board, or odd shapes, such as round stock, are used, the task of aligning the boards and clamping the boards in-between bar clamps can be burdensome indeed. One such clamping device proposed for joining wide boards edgewise includes a screw to draw two barrel nuts together that are inserted within pilot holes drilled into the boards. The joint is secured tightly by adjusting the screw between the two barrel nuts. While such a clamping device is not size dependent in relation to the scale of the boards, the device does require that pilot holes be drilled into the surface of the boards in order to secure barrel nuts. Drilling of these holes requires care and skill to avoid unwanted damage such as accidental drilling through to the opposite face and in any event leaves the unsightly holes visible in the finished product themselves. Moreover such devices are not adaptable for practical use in joining oddly configured components such as round stock or cylindrically shaped molding. Finally, for smaller pieces, an adjustable corner and splicing clamp has been employed consisting of a pair of vise-like clamps adjustably mounted on a protractor for clamping miter or butt joints at any selected angle as required. In a device of this type, the two vises are rotated into position along the protractor and the boards may be secured at their widths by the vises. While such devices work well for picture frames and the splicing of molding and trim, the vise clamps prove inadequate for securing larger boards together. Wood workers have from time to time been forced to rely on trial and error techniques which often include extensive shaving or sanding of the confronting edges prior to the application of glue to the confronting edges. None of the clamping devices or techniques of the prior art offer a practical device allowing for alignment of the boards to be glued to establish the desired orientation and alignment and then for separation to expose the confronting edges for application of glue or other bonding material while monitoring such established orientation and alignment for pressing of such boards back together without requiring that the boards be realigned. Thus a need exists for a universal clamping device that maybe applied to different sizes and configurations of components to be joined together, that does not affect or intrude upon the fit or the integrity of the boards and allows for adjustment of the boards while maintaining their alignment. SUMMARY OF THE INVENTION The clamping apparatus of the present invention is characterized by a pair of base plates formed with upwardly facing support surfaces for securing a pair of respective components thereon during the process of gluing their confronting edges together wherein each base plate includes respective clamps to maintain the respective boards fixed against the base plates. Included between the two base plates is a rail that couples the first and second base plates together and permits movement of the second base plate therealong permitting the two base plates, with the components affixed therein, to be separated apart for access of glue to the edges, and then to be pressed together without disturbing alignment of such components. A trigger shaped press, mounted on the second base plate, when actuated, incrementally draws the second base plate along the rail towards the first base plate firmly pressing the confronting edges of the two boards clamped thereon together. The present invention provides the opportunity to refine the confronting edges of the components and apply the glue after the boards have been securely aligned in the clamp. Once glue has been applied to the components, the press is actuated to draw the confronting edges together. It is a further object of this invention to permit the clamping apparatus to pivot the base plates about a pivot axis to allow for the angular displacement of the base plates to be adjusted according the joint angle formed by the connection of the two components. Other objects and features of the invention will become apparent from consideration of the following description taken into connection with the accompanying drawing. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a clamping apparatus embodying the present invention; FIG. 2 is a partial top plan view, in enlarged scale, taken along line 2--2 of FIG. 1; FIG. 3 is a top plan view similar to FIG. 2 showing the clamping apparatus rotated about its center axis; FIG. 4 is a top plan view similar to FIG. 2 showing the clamping apparatus rotated about its center axis opposite to FIG. 3; FIG. 5 is a transverse sectional view in enlarged scale, taken along line 5--5 of FIG. 1; FIG. 6 is a longitudinal front sectional view, in enlarged scale, taken along line 6--6 of FIG. 1; FIG. 7 is a transverse sectional view, in enlarged scale, taken along line 7--7 of FIG. 6; FIG. 8 is a partial longitudinal sectional view, taken along line 8--8 in FIG. 6; FIG. 9 is a transverse sectional view taken along line 9--9 of FIG. 6; FIG. 10 is a partial back view taken along line 10--10 of FIG. 9; and FIG. 11 is a longitudinal top view taken along line 11--11 of FIG. 9. DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the clamping apparatus of the present invention includes, generally, a pair of base plates 14 and which may be of a generally rectangular brick-like shape and pivotally connected together along an elongated rail 18 on which plate 16 slides. The base plates support respective upstanding C-clamps, generally designated 20 and 22, for selectively clamping components such as boards 23 to the respective top surfaces of such base plates 14 and 16. A friction press, generally designated 24, mounted in the base plate 16 controls movement of such plate relative to the base plate 14 and is operative to provide a mechanical advantage in selectively driving base plate 16 and, consequently, a component clamped thereon, toward the base plate 14. Thus, the plates 14 and 16 may be adjusted to a selected position such as that shown on FIG. 1 and components such as flat boards 23 and 25 positioned thereon in contacting edgewise relations, the clamps 20 and 22 closed to secure such components in relative mating position on such base plates. The press 24 may then be released to free the base plate 16 to slide on the rail 18 away from base plate 14 to expose the confronting edges of such components for application of glue. The base plate 16 may then be slid freely back on the rail 18 to shift the component 25 back into mating contact as previously established with component 23. The press 24 may then be activated to press the plate 16 toward the plate 14 to thoroughly press the edges of the components 23 and 25 firmly together while maintaining the previously established relationship. The main support for the components 23 and 25 is provided by the base plates 14 and 16 that consist of rectangular wooden blocks having an overall brick-like shape tapered at the corners of their proximal ends to form respective chamfers 26. The upper surface 27 of each of the blocks is textured or coated with a grit matting to prevent sliding of the components when placed on the blocks. The wooden blocks provide a firm rigid support surface for the components 23 and 25 that is lightweight and easy to manufacture. The use of wooden base plates also reduces the risk of damage to components 23 and 25 due to scratching during mounting of the components as would be encountered with metal base plates. Each of the base plates 14 and 16 include tapered corners 26 at their respective confronting proximal ends thereby reducing the surface area of the proximal end. With reference to FIGS. 1-4, 6 and 8, the first base plate 14 is formed at one extremity with a semi-cylindrical concavity 28 carved out of the upper half and a cylindrical tongue 30 projecting from the lower half and configured with the same radial center point as that of the concavity 28. On the upper surface of the first base plate 14, a central pointer mark 32 extends longitudinally to the edge of the concavity end to visibly identify the center point of the concavity 28. At the radial center point of the tongue, a bore hole 34 extends through the center of the tongue with a counter bore 36 on the underside of the tongue. A threaded bore hole 38 (FIG. 6) is drilled through the tongue at a point half way between the counter bore 36 and the proximal end 28 of the first base plate 14. The bore hole 38 threadably receives a set screw 40 terminating at its upper extremity in an index tip 42 projecting about the top surface of such tongue. It will be appreciated that the function of the index screw is only to establish a positive angular relationship between the base plates 14 and 16 and may take many different forms. The threaded bore 38 could be in the form of a blind bore drilled at the same location in the upper surface of the tongue and housing an open ended barrel having a retainer rim about the open end to retain a spring loaded index ball to be pressed into selective engagement with indents. With continued reference to FIGS. 1-4, 6 and 8, the proximal end of a second base plate 16 is shaped with a cylindrical concavity 44 that complements the curvature of the end of the cylindrical tongue 30 to be abutted thereagainst. Formed centrally along the longitudinal axis of base plate 16 is an open ended slot 46 (FIG. 6). The slot 46 may be of either rectangular or cylindrical in cross section. The distal extremity of the plate 16 is hollowed out to form a downwardly opening clamp chamber 48 (FIGS. 5 and 6). Referring to FIG. 6, a blind bore 50 is drilled longitudinally into the proximal end of the plate 16 centrally in the concavity 44 aligned under the slot 46 to receive an open ended barrel 52 having a retainer rim 54 about the open end. A ball bearing 56 is housed in the barrel to be biased against the rim 54 by means of a bias spring 58. A cylindrical disk 60 (FIGS. 1 and 6) having the same thickness and diameter as the tongue 30 of the first base plate 14 overlies the tongue and cooperates therewith to form a central hub 62. From a counter sunk cavity 64 on the upper side of the disk 60, a bore hole 66 extends through the cylindrical center of the disk and aligns with the bore hole 34 in the tongue 30. On the underside of the disk 60, a diametrical, open ended mortise 68 is carved to align with the end of the slot 46 (FIG. 6). Referring to FIG. 8, a plurality of index bores 70 and 72 are drilled into the underside of the disk and correspond to predetermined angular locations 90', 180' and 270' with respect to the radius formed by the mortise 68. The index bores 70 and 72 are all drilled on the same radius as the threaded bore 38 in the tongue 30 of base plate 14 so the set screw will, when clocked to the appropriate position, align therewith. Referring to FIGS. 1-4, protractor indicia 74 is printed about the periphery of the top side of the disk 60 to register with the pointer 32. The tension rail 18 telescopes from the tensioning chamber 48, through the slot 46 (FIG. 6) and into the mortise 68 and is formed with a bore 76 aligned with the tongue bore 34 and disk bore 66. A bolt 78 extends through the bores 66, 76 and 34 such that the head 80 of the bolt nests in the counter sunk cavity 64 in the disk 60 and a nut 82 is threadably secured to the bolt, housed in the counter sunk cavity 36 on the underside of the tongue. Although firmly secured, the rod 18 and disk 60 are free to pivot about the central bore hole with respect to the base plate tongue 30. A pistol-handled friction press 24 (FIG. 5) is housed in the chamber 48 of the base plate 16 and secured by a pair of wood screws 84. While friction press 24 may take many different forms, the one selected for illustration is similar in design to the trigger presses found on commercially available caulking guns. A rectangular frame 86 is housed within the chamber 48 formed at the backside proximal corner with a pistol handle 88 that extends laterally out of the backside opening 90 in the cavity. The rectangular frame 86 includes a thick rim 92 that extends from the free end of the handle 88 along the proximal end of the frame to the front side distal corner 94 of the frame opposite from where the handle begins. When viewed laterally, the handle and rim combine to exhibit a T-shape appearance that structurally enhances the handle to withstand the torque forces applied to it by the craftsman's grasp. The rim side of the handle is contoured to ease in gripping the handle. The rod 18 is inserted through the proximal end of the second base plate with the free end 96 of the rod 18 extending out the distal end. The rectangular frame 86 receives the rod 18 through a longitudinal slot 98 formed in the frame where at the receiving end of the frame a spring biased friction latch 100 and release 102 is secured to the frame by an overhanging lip 104 or J-hook projecting longitudinally away from the front side corner of the frame 86. The friction latch 100 includes a vertically extended oval shaped aperture (not shown) with a lower edge that is biased by a spring 106 to frictionally grip the underside 108 of the rod to prevent withdrawal of the second base plate toward the free end of the rod. A latch release 102 is connected to the friction latch 100 with a free end that extends out of the second base plate 16 in spaced apart relation to the handle 88 such that, when sufficient pressure to counter the spring bias is applied to the release 102, the lower end of the friction latch 100 is drawn towards the handle thus freeing the rod from the lower edge of the aperture. A release stop 110 extends horizontally out of the lower corner of the frame to stop the friction latch at the point where the rod is freed therefrom. A trigger 112 (FIG. 5) pivotally carried from the frame near the base of the handle includes a trigger grip 114 molded with finger contours that diverges out from the handle base such that the free end of the trigger 112 is in spaced apart relation with the free end of the handle 88. Side supports 116 on the trigger slide over opposite sides of the frame 86 and a cross-member 118 pivotally connects the trigger to the frame. A second cross member 120 bolts to the free ends of the trigger side supports 116. A spring biased friction press 124, located within an aperture 122 in the frame 86, is biased against the second cross member 120 by a spring 123 and receives the rod through a vertically extended oval aperture in the friction press. Referring to FIGS. 1 and 9-11, respective upstanding C-clamps 20 and 22 are mounted on the base plates by a pair of bolts 126 securing the respective clamps 20 and 22 to the base plates 14 and 16. With reference to the second base plate clamp 22, an upstanding T-shaped neck 128 rises above the upper surface of the base plate 16 onto which a boss 130 is mounted in overlying relation to the upper surface 27 of the base plate. The boss 130 includes a threaded bore 132 (FIG. 11) supporting a screw 134 therein. A handle 136 (FIG. 9) is attached to the upper end of the screw and a foot 138 couples to the lower end of the screw. The foot is generally in the shape of a horizontal tombstone (FIG. 11) having a rounded front end 140 to receive wood stock 25 without damaging the wood stock against sharp corners. Carried from the rear end of the foot a pair of rearwardly projecting inturned cleats 142 slidingly capture the outer edges 144 of the upstanding neck. Formed in the underside of the foot, a V-groove 146 extends width-wise across the foot to accommodate the periphery of round stock, alternatively the grooves could be formed in the top surface of the underlying base plates. In operation, a wood worker must first prepare the clamping apparatus for the task at hand. If frames or oddly shaped components are to be joined, then the base plates 14 and 16 may be pivoted to the corresponding angle formed by the joined components 23 and 25. The base plates may be pivotally rotated to any angle within 90 degrees on either side of each other. The tapered clearance corners 26 on the proximate ends of the base plates 14 and 16 allow this increased range of rotation about the hub 62. The index mark 32 and protractor indicia 74 cooperate to allow the wood worker to exactly align the base plates 14 and 16 to the necessary joint angle. Once the angle between the base plates has been achieved, the angle may be secured by rotating the set screw 40 until its tip 42 contacts the disk 60 above the tongue 30. Index bores 70 and 72 in the disk 60, located at the most often used pivot angles, receive the tip 42 of the set screw 40 thereby locking the angular displacement of the base plates securely in the selected angle. Once the desired angle has been selected, the release 102 on the second base plate 16 is drawn towards the handle 88 of the friction press 24 to allow the rail 18 to telescope freely through the second base plate 16 thus allowing the second base plate 16 to be adjusted in a slight spaced apart relationship to the hub 62. Finally, the respective clamp handles 136 are rotated until each foot 138 is raised sufficiently away from the upper surface 27 of the base plates to receive the components 23 and 25 in between. Once the clamping device has been properly adjusted, the respective components 23 and 25 to be joined are placed on the textured upper surface 27 of the base plates. The confronting edges are positioned in contact with one another and the C-clamps 20 and 22 are closed to secure the respective components against the upper surface 27 of the base plates 14 and 16. It will be appreciated that the spacer ball 54 will serve to maintain the base plate 16 spaced distally from the tongue 30 and hub disk 32 by about 1/16 of an inch even though the edges of the boards 23 are in intimate contact. The press may be released so the plate 16 can be freely slid thereon away from the plate 14 to space the adjacent edges of the boards 23 and 25 apart so ready access can be had thereto. Glue may then be applied to the spaced apart edges of the board and the friction press 24 actuated to release the grip on the rail 18 to free the plate 18 so it can be slid toward the hub. The press may then be operated to incrementally draw the base 16 toward the plate 14 thus retracting the spacer ball 54 into the barrel 50 (FIG. 6) to provide for the components 23 and 25 to be drawn firmly together. By incrementally drawing the base plates together, the craftsman is able selectively chose the necessary amount of pressure to be applied to the confronting edges of the respective components thereby insuring that all of the glue is not squeezed out of the joint by the clamping device. When the components have dried, the clamps 20 and 22 are opened and the joined components removed. It will be appreciated that with the articulation capability about the hub, the plate 16 may be selectively rotated about such hub to the position shown in FIG. 3 so that the respective clamps are positioned facing outwardly at 90° from one another. It will be appreciated by those skilled in the art that, in this orientation, the clamp apparatus may be conveniently fitted into the inside corner of, for instance, a frame with 90° corners to thus clamp the adjacent frame components by such clamp so they may be drawn together by the press. Similarly, in the orientation shown in FIG. 4, the clamps 20 and 22 will be facing inwardly so they may be clamped over the outside edges of 90° frame components so the press may be utilized to draw such components together from the outside. From the foregoing, it will be apparent that the clamp apparatus of the present invention is economical to make, convenient to operate and effective to provide for effective pressing together of odd configured or particularly wide components. Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention.

A multi-purpose clamping apparatus to join the confronting edges of two boards together during a gluing process having a pair of base plates, a central hub about which the base plates may be rotated, a rail projecting laterally from the hub on which one of the base plates is connected and a press mounted on one of the base plates and engaging the rail for drawing the base plates together. Respective clamps overlie the upper surface of the base plates.

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of International Patent Application No. PCT/CN2012/086495 with an international filing date of Dec. 13, 2012, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201110454000.5 filed Dec. 30, 2011. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. Inquiries from the public to applicants or assignees concerning this document or the related applications should be directed to: Matthias Scholl P. C., Attn.: Dr. Matthias Scholl Esq., 245 First Street, 18th Floor, Cambridge, Mass. 02142. BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of preparing a graphene oxide/rubber nanocomposite which has high delamination degree, high dispersion degree, and strong interfacial boding action, particularly to a method of preparing a graphene oxide/rubber nanocomposite contaning a surfactant made by emulsion compounding with flocculation process or by emulsion compounding with spray drying process. 2. Description of the Related Art In rubber industry, the most widely used fillers are nano sized carbon black and white carbon black. Carbon black is the most important reinforcing fillers for rubber industry. However, as the petroleum resources are running out, carbon black industry which absolutely relies upon petroleum industry is restricted. In addition, the production and application of carbon black cause environment pollution. The reinforcing property of white carbon black to rubber is close to that of carbon black to rubber. However, rubber filled by white carbon black has weaknesses. Particularly, during production, it's hard to mix white carbon black with rubber. Once carbon black does not evenly disperse in rubber, the rubber exhibits low intensity and poor property. Submicron sized and micron sized non-metallic mineral materials are also used as fillers in rubber industry, and the most widely used materials are ceramics and calcium carbonate, dolomite, aedelforsite, talcum, cryolite, pyrophillite, and barite. These fillers are used for the purpose of reducing cost, and do not contribute to the intensity of rubber. Therefore, it is one objective to develop new reinforcing fillers (low consumed, environmental friendly, and free of petroleum resources) to replace conventional fillers and to provide an efficient, convenient, and economic method in rubber industry. Graphene is a hexagonal flat film of carbon atoms formed by sp 2 hybrid orbitals, and is a two dimensional material at a length of one or several carbon atoms. In 2004, Novoselov and Geim from the University of Manchester prepared self-existent two dimensional graphene crystals for the first time by using a tape to delaminate highly oriented graphite. Since graphene has infinite periodically repeated structures in a flat surface and has a nano sized length in a direction perpendicular to the flat surface, graphene can be regarded as a nano material having a macro size. Graphene has a high specific area in theory (about 2630 m 2 /g), large aspect ratio (>1000), and excellent mechanical strength (Young's modulus of graphene is 1060 GPa). Therefore, graphene exhibits potential advantages for efficient reinforcement of polymer materials. Structurally complete graphene has high chemical stability. The surface of structurally complete graphene is inert, and the interactions between structurally complete graphene and other medium (such as a solvent) are weak. Van Der Waals force between different sheets of graphene is strong, and thus, graphene powders are prone to aggregate and are hard to dissolve in water or common organic solvents. This causes great difficulties for preparing graphene/polymer composites. Reducing graphite oxide is the mostly widely used method for preparing graphene. Graphite oxide is an intermediate during the process of reducing graphite oxide to produce graphene. Graphite oxide is completely delaminated and changes into graphene oxide by a process of dispersing graphite oxide in water or organic solvent and further processing graphite oxide by ultrasonic waves. There are many oxygen functional groups on the surface of graphene oxide so that graphene oxide is compatible with water and common organic solvents, Van Der Waals force between different sheets of graphene oxide is weakened, and aggregation degree is reduced. Until now, graphene oxide has been used as a reinforcing filler and has been successfully dispersed into polymers having hard plastic substrate (such as polyvinyl acetate, polymethyl methacrylate, and polycaprolactone). (Xu, Y.; Hong, W; Bai, H.; Li, C.; Shi, G Carbon 2009, 47, 3538-3543. Liang, J.; Huang, Y.; Zhang, L.; Wang, Y.; Ma, Y.; Guo, T.; Chen, Y. Adv, Funct. Mater. 2009, 19, 2297-2302. Jang, J. Y.; Kim, M. S.; Jeong, H. M.; Shin, C. M. Compos. Sci. Technol. 2009, 69, 186-191. Kai, W.; Hirota, Y.; Hua, L.; Inoue, Y. J. Appl. Polym. Sci. 2008, 107, 1395-1400. Cai, D.; Song, M. Nanotechnology 2009, 20, 315708/1-315708/6). However, it's a pity that advanced preparation technology which efficiently composites graphene oxide and rubber (simple, easy to industrialize, and obtaining a product having good properties) was not reported as yet. The preparation of excellent rubber products relies upon the solution to dispersion of graphene oxide in rubber and interfacial bonding between graphene oxide and rubber. SUMMARY OF THE INVENTION In view of the above-described problems, it is one objective of the invention to provide a graphene oxide/rubber nanocomposite which has high delamination degree, high dispersion degree, and strong interfacial boding action. Graphene used in this method is graphene oxide, and does not undergo a reducing process (Reducing Graphene oxide results in the aggregation of graphene and interferes the dispersion of graphene; surface functional groups of reduced graphene greatly reduce, and reduced graphene is not compatible with rubber). In the composite made by this method, graphene oxide is highly delaminated, highly dispersed, and present in nano sizes so that graphene oxide exhibits a reinforcement property. Also, the strong interfacial bonding between graphene oxide and rubber strengthens the rubber. According to testing results, adding graphene oxide to rubber greatly improves the intensity, resistance, and air barrier performance of rubber. Therefore, the composite can be widely used in industrial products including tires, rubber slabs, rubber tapes, and rubber rollers, and in sealing field. In addition, the composite can be widely used as self-repairing material and tear-resistant material because graphene oxide has excellent restorability and crack growth resisting property. In accordance with one embodiment of the invention, there is provided a method of preparing a graphene oxide/rubber nanocomposite, which has high delamination degree, high dispersion degree, and strong interfacial boding action, by emulsion compounding with flocculation process or by emulsion compounding with spray drying process. The method not only is used for reinforcing rubber and improving air barrier performance of rubber, but also provides basis for preparing highly electricity conducting materials and highly heat conducting materials in the future. The method comprises: (1) preparing a graphene oxide/water sol: dispersing graphene oxide in deionized water, and treating by ultrasonic waves for 10 min-6 h at a temperature of 0-100° C., at a power of 10-1000 W, and at a frequency of 10-20000 Hz to obtain the graphene oxide/water sol; (2) pretreating the graphene oxide/water sol: adding a surfactant to the graphene oxide/water sol, treating by ultrasonic waves for 5 min-5 h or stirring for 5 min-5 h at a stirring speed of 50-10000 r/min to obtain a pretreated graphene oxide/water dispersion; (3) preparing a graphene oxide/rubber compounding emulsion: treating the graphene oxide/water sol or the graphene oxide/water dispersion in addition to a rubber latex by ultrasonic waves for 10 min-6 h, or stirring the graphene oxide/water sol or the graphene oxide/water dispersion in addition to the rubber latex for 10 min-6 h at a stirring speed of 50-10000 r/min, to obtain a stabilized graphene oxide/rubber compounding emulsion; (4) preparing a graphene oxide/rubber nanocomposite: A) ion flocculation process: adding a flocculant which demulsifies the graphene oxide/rubber compounding emulsion to perform flocculation, dehydrating and drying a flocculate to obtain the graphene oxide/rubber nanocomposite; B) spray drying process: passing the graphene oxide/rubber compounding emulsion through a spray drier to produce small composite liquid drops, and dehydrating the composite liquid drops in a drying medium to obtain the graphene oxide/rubber nanocomposite; or adding a gasified flocculant to the drying medium of the spray drier to simultaneously perform flocculation and dehydration to obtain the graphene oxide/rubber nanocomposite. The advantages of this invention lie in that graphene oxide is used as the reinforcing fillers. In water, the oxygen functional groups on the surface of graphene oxide are ionized so that the surface of graphene oxide is negatively charged and graphene oxide forms a stable sol because of an electrostatic force. Particularly, graphene oxide is highly delaminated and is highly dispersed into nano sizes. This is the first structural base of this invention. Adding to the graphene oxide/water sol specific compounds, which form ionic bonding or chemical bonding with the surface functional groups of graphene oxide, as surfactants between molecular chains of graphene oxide and rubber to improve the interfacial bonding between graphene oxide and rubber. This is the second structural base of this invention. Mixing the graphene oxide/water sol or the graphene oxide/water dispersion with the rubber latex and treating by ultrasonic waves or stirring. The emulsion particles and graphene oxide sheets interpenetrate each other while separate from each other so that graphene oxide/rubber dispersion which is highly delaminated and highly dispersed is formed in solution. This is the third structural base of this invention. The advantage of this invention also lies in that utilizing ion flocculation process or spray drying process to prepare the graphene oxide/rubber nanocomposite. The phase behavior of the graphene oxide/rubber compounding emulsion in liquid form is retained by the graphene oxide/rubber nanocomposite obtained in this invention and, thus, the graphene oxide/rubber nanocomposite, which is highly dispersed, highly delaminated, and present in nano sizes, is obtained. This is the technical mechanism of this invention. In the graphene oxide/rubber nanocomposite, the graphene oxide fillers is 0.1 phr-20 phr (phr is the weight parts of graphene oxide per every hundred weight parts of rubber), and the surfactant is 0.01 phr-100 phr (phr is the weight parts of the surfactant per every hundred weight parts of rubber). The surfactant in this invention has a solid content of 10-80 wt %, and is one or two compounds selected from the group consisting of carboxylic styrene butadiene latex, butadiene-vinylpyridine copylymer latex, carboxylated styrene-butadiene latex, epoxy latex, carboxylic chloroprene rubber latex, carboxylic acrylonitrile styrene butadien rubber latex, and carboxyl polybutadiene; and silane coupling agent, such as amino-propyl-tri-ethoxy silane coupling agent KH550 and γ-(methacryloxypropyl)-tri-methoxy silane coupling agent KH570, and quaternary ammonium salt. The rubber latex is selected from the group consisting of styrene butadiene latex, natural latex, neoprene latex, butyl latex, NBR latex, butadiene latex, ethylene propylene rubber latex, polyisoprene rubber latex, fluorine rubber latex, silica rubber latex, and polyurethane rubber latex which have a solid content of 10-80 wt %. The flocculant is selected from the group consisting of sulphuric acid, hydrochloric acid, calcium chloride, sodium chloride, potassium chloride, sodium sulphate, aluminium sulphate, ferric trichloride, poly aluminium chloride, and poly ferric chloride which have a percentage of 0.1-10 wt % (not otherwise specified, refers to percentage by weight). Preferably, the solid content of graphene oxide in the graphene oxide/water sol is 0.01-20 wt %. Preferably, the flocculate is dried at a temperature of ≦300° C. Preferably, the drying medium in the spray drier is hot air having a temperature of 60-300° C. A vulcanizate which is obtained by mixing and vulcanizing the graphene oxide/rubber nanocomposite exhibits high tensile strength, tensile strength at definite elongation, and tearing strength. Also, the air barrier performance of the vulcanizate is significantly improved. For instance, in Example 4 of this application, a vulcanizate is made from the graphene oxide/rubber nanocomposite. When graphene oxide in the graphene oxide/rubber nanocomposite is 4 phr, the composite styrene butadiene rubber has a tensile strength of 14.2 MPa (7.1 times that of pure styrene butadiene rubber), a tensile strength at 100% elongation of 3.7 MPa and a tensile strength at 300% elongation of 11.1 MPa respectively (3.7 times and 5.6 times those of pure styrene butadiene rubber respectively), and an air barrier performance of 2.35×10 −17 m 2 s −1 Pa −1 ( 3/10 of that of pure styrene butadiene rubber; the smaller the value is, the better the air barrier performance is). The advantages of this invention lie also in simple process, low cost, no environment pollution, and feasibility of large-scale industrialization. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B show atom force microscope (AFM) images of a graphene oxide in graphene oxide/water sol. The AFM images show that graphene oxide is present in a single sheet or few sheets and that the traverse scale of graphene oxide is micron sized and the longitudinal scale of graphene oxide is nano sized. FIGS. 2A and 2B show transmission electron microscope (TEM) images of graphene oxide in a graphene oxide/water sol. The TEM images show that there are obvious folding structures at the edge of graphene oxide. FIGS. 3A and 3B show high resolution transmission electron microscope (HRTEM) images of a graphene oxide/styrene butadiene rubber nanocomposite (Example 4). The HRTEM images show that graphene oxide is evenly dispersed in the styrene butadiene rubber substrate in a form of single sheet. FIG. 4 shows X-ray diffraction profiles of graphite oxide, a styrene butadiene rubber vulcanizate (Contrast 1), and graphene oxide/styrene butadiene rubber vulcanizates (Examples 1 and 9). It is shown that characteristic diffraction peaks of graphene oxide in the graphene oxide/styrene butadiene rubber nanocomposite do not occur. Thus, graphene oxide is present in a form of single sheet and is highly delaminated in the styrene butadiene rubber substrate. FIG. 5A shows Akron abrasion Schallamach pattern of a graphene oxide/styrene butadiene rubber vulcanizate (Example 10); FIG. 5B shows Akron abrasion Schallamach pattern of a white carbon black/styrene butadiene rubber vulcanizate (Contrast 2). It is shown that the Schallamach pattern of the graphene oxide/styrene butadiene rubber vulcanizate is clear and that the rubber substrate and graphene oxide are not massively delaminated. Thus, the interfacial bonding between graphene oxide and the rubber substrate is excellent. DETAILED DESCRIPTION OF THE EMBODIMENTS For further illustrating the invention, embodiments detailing a method of preparing a graphene oxide/rubber nanocomposite are described below. It should be noted that the following examples are intended to describe and not to limit the invention. Contrast 1 Adding a calcium chloride solution having a concentration of 1% to 500 g styrene butadiene latex (the solid content is 20 wt %) to perform flocculation; water washing a styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a styrene butadiene rubber flocculated gel. Mixing the styrene butadiene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a styrene butadiene rubber vulcanizate. Properties of the styrene butadiene rubber vulcanizate are tested according to national standards. Data of mechanical properties of the styrene butadiene rubber vulcanizate are shown in Table 1, and data of air barrier performance of the styrene butadiene rubber vulcanizate is shown in Table 2. X-ray diffraction profiles of the styrene butadiene rubber vulcanizate are shown in curve (a) of FIG. 4 . Example 1 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 100 g of the graphene oxide/water sol with 0.625 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 0.1 phr and the surfactant is 0.25 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. X-ray diffraction profiles of the vulcanizate are shown in curve (b) of FIG. 4 . Example 2 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 1200 g of the graphene oxide/water sol with 7.5 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 1.2 phr and the surfactant is 3 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. Example 3 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 2000 g of the graphene oxide/water sol with 12.5 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 2 phr and the surfactant is 5 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. Example 4 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 4000 g of the graphene oxide/water sol with 25 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 4 phr and the surfactant is 10 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. Example 5 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 8000 g of the graphene oxide/water sol with 50 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 8 phr and the surfactant is 20 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. Example 6 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 16000 g of the graphene oxide/water sol with 100 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 16 phr and the surfactant is 40 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. Example 7 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 24000 g of the graphene oxide/water sol with 150 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 24 phr and the surfactant is 60 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. Example 8 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 32000 g of the graphene oxide/water sol with 200 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 32 phr and the surfactant is 80 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. Example 9 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 40000 g of the graphene oxide/water sol with 250 g butadiene-vinyl pyridine latex (the solid content is 40 wt %) for 10 min at a stirring speed of 500 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 20 min at a stirring speed of 500 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 40 phr and the surfactant is 100 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 1, and data of air barrier performance of the vulcanizate is shown in Table 2. X-ray diffraction profiles of the vulcanizate are shown in curve (c) of FIG. 4 . TABLE 1 Mechanical Properties of Graphene Oxide/Styrene Butadiene Rubber Vulcanizate Made by Emulsion Compounding with Flocculation Process Tensile Tensile Shore Strength at Strength at Scleroscope 100% 300% Tensile Tearing Hardness in Elongation/ Elongation/ Strength/ Elongation Tension Strength/ Sample A scale MPa MPa MPa at Break/% Set/% kN/m Contrast 1 52 1.0 2.0 2.3 339 0 16.6 Example 1 54 1.3 3.4 3.9 354 0 22.5 Example 2 60 1.7 4.8 7.3 367 4 35.9 Example 3 66 2.5 7.4 9.5 388 4 47.0 Example 4 73 3.7 11.1 14.2 423 8 49.7 Example 5 77 4.7 12.5 18.9 574 16 53.9 Example 6 79 4.9 12.9 24.2 690 24 57.4 Example 7 82 5.2 13.2 23.9 688 20 62.8 Example 8 88 5.4 13.4 24.7 700 18 65.4 Example 9 92 5.1 12.7 24.0 696 22 64.7 TABLE 2 Air barrier performance of Graphene Oxide/Styrene Butadiene Rubber Vulcanizate Made by Emulsion Compounding with Flocculation Process Air Barrier Performance/ Sample 10 −17 m 2 s −1 Pa −1 Contrast 1 6.97 Example 1 3.02 Example 2 2.28 Example 3 1.73 Example 4 1.42 Example 5 1.21 Example 6 1.09 Example 7 0.92 Example 8 0.78 Example 9 0.71 Contrast 2 Adding a calcium chloride solution having a concentration of 1% to 500 g styrene butadiene latex (the solid content is 20 wt %) to perform flocculation; water washing a styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a styrene butadiene rubber flocculated gel. Mixing the styrene butadiene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (50 parts by weight of white carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a white carbon black/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. Example 10 Adding 10 g graphite oxide to 0.1 L water, treating by ultrasonic waves for 4 h at a power of 1000 W, at a frequency of 2000 Hz, and at a temperature of 40° C. to obtain a graphene oxide/water sol having a solid content of 10 wt %. Mixing 100 g of the graphene oxide/water sol with 1 g carboxylic styrene butadiene latex (the solid content is 30 wt %) for 20 min at a stirring speed of 2000 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 40 min at a stirring speed of 2000 r/min. Adding calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 10 phr and the surfactant is 0.3 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. Contrast 3 Adding a dilute sulphuric acid solution having a concentration of 10% to 167 g natural latex (the solid content is 60 wt %) to perform flocculation; water washing a styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 50° C. for 36 h to obtain a natural rubber flocculated gel. Mixing the natural rubber flocculated gel in a two roll rubber mixing mill according to a formulation (50 parts by weight of white carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 143° C. during the optimum cure to obtain a white carbon black/natural rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. Example 11 Adding 5 g graphite oxide to 1 L water, treating by ultrasonic waves for 1 h at a power of 1000 W, at a frequency of 1000 Hz, and at a temperature of 100° C. to obtain a graphene oxide/water sol having a solid content of 0.5 wt %. Mixing 2000 g of the graphene oxide/water sol with 10 g natural epoxy latex (the solid content is 42 wt %) for 30 min at a stirring speed of 1000 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 167 g natural epoxy latex (the solid content is 60 wt %) and further mixing for 30 min at a stirring speed of 1000 r/min. Adding dilute sulphuric acid solution having a concentration of 10% to perform flocculation. Water washing a graphene oxide/natural rubber micelle obtained by the flocculation, and dehydrating at 50° C. for 36 h to obtain a graphene oxide/natural rubber nanocomposite in which graphene oxide is 10 phr and the surfactant is 4.2 phr. Mixing the graphene oxide/natural rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 143° C. during the optimum cure to obtain a graphene oxide/natural rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. Contrast 4 Mixing 350 g styrene butadiene latex (the solid content is 20 wt %) with 50 g butadiene latex (the solid content is 40 wt %) and stirring. Adding a calcium sulphate solution having a concentration of 6% to perform flocculation; water washing a styrene butadiene rubber/butadiene rubber micelle obtained by the flocculation, and dehydrating at 200° C. for 1 h to obtain a styrene butadiene rubber/butadiene rubber flocculated gel. Mixing the styrene butadiene rubber/butadiene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (50 parts by weight of white carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a styrene butadiene rubber/butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. Example 12 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 3 h at a power of 600 W, at a frequency of 500 Hz, and at a temperature of 30° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 10000 g of the graphene oxide/water sol with 10 g butadiene-vinylpyridine latex (the solid content is 40 wt %) for 30 min at a stirring speed of 1000 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 350 g styrene butadiene latex (the solid content is 20 wt %) and 50 g butadiene latex (the solid content is 40 wt %), and further mixing for 3 h at a stirring speed of 1000 r/min. Adding calcium sulphate solution having a concentration of 6% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber/butadiene rubber micelle obtained by the flocculation, and dehydrating at 200° C. for 1 h to obtain a graphene oxide/styrene butadiene rubber/butadiene rubber nanocomposite in which graphene oxide is 10 phr and the surfactant is 4 phr. Mixing the graphene oxide/styrene butadiene rubber/butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber/butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. Contrast 5 Mixing 117 g natural latex (the solid content is 60 wt %) with 54.5 g ethylene propylene latex (the solid content is 55 wt %) and stirring. Adding a calcium sulphate solution having a concentration of 1% to perform flocculation; water washing a natural rubber/ethylene propylene rubber micelle obtained by the flocculation, and dehydrating at 70° C. for 24 h to obtain a natural rubber/ethylene propylene rubber flocculated gel. Mixing the natural rubber/ethylene propylene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (50 parts by weight of white carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 145° C. during the optimum cure to obtain a natural rubber/ethylene propylene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. Example 13 Adding 10 g graphite oxide to 1 L water, treating by ultrasonic waves for 3 h at a power of 600 W, at a frequency of 500 Hz, and at a temperature of 30° C. to obtain a graphene oxide/water sol having a solid content of 1 wt %. Mixing 1000 g of the graphene oxide/water sol with 1 g butadiene-vinylpyridine latex (the solid content is 40 wt %) for 30 min at a stirring speed of 1000 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 117 g natural latex (the solid content is 60 wt %) and 54.5 g ethylene propylene latex (the solid content is 55 wt %), and further mixing for 3 h at a stirring speed of 1000 r/min. Adding calcium sulphate solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/natural rubber/ethylene propylene rubber micelle obtained by the flocculation, and dehydrating at 70° C. for 24 h to obtain a graphene oxide/natural rubber/ethylene propylene rubber nanocomposite in which graphene oxide is 10 phr and the surfactant is 0.4 phr. Mixing the graphene oxide/natural rubber/ethylene propylene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 145° C. during the optimum cure to obtain a graphene oxide/natural rubber/ethylene propylene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. Contrast 6 Adding a dilute hydrochloric acid solution having a concentration of 1% to 357 g acrylonitrile butadiene latex (the solid content is 28 wt %) to perform flocculation; water washing an acrylonitrile butadiene rubber micelle obtained by the flocculation, and dehydrating at 300° C. for 1 h to obtain an acrylonitrile butadiene rubber flocculated gel. Mixing the acrylonitrile butadiene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (50 parts by weight of white carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 160° C. during the optimum cure to obtain a acrylonitrile butadiene rubber vulcanizate. Properties of the acrylonitrile butadiene rubber vulcanizate are tested according to national standards. Data of mechanical properties of the acrylonitrile butadiene rubber vulcanizate are shown in Table 3, and Akron abrasion value of the acrylonitrile butadiene rubber vulcanizate is shown in Table 4. Example 14 Adding 10 g graphite oxide to 1 L water, treating by ultrasonic waves for 1 h at a power of 1000 W, at a frequency of 1000 Hz, and at a temperature of 100° C. to obtain a graphene oxide/water sol having a solid content of 1 wt %. Mixing 1000 g of the graphene oxide/water sol with 1 g carboxylic acrylonitrile butadiene latex (the solid content is 20 wt %) for 30 min at a stirring speed of 1000 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 357 g acrylonitrile butadiene latex (the solid content is 28 wt %) and further mixing for 1 h at a stirring speed of 1000 r/min. Adding a calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/acrylonitrile butadiene rubber micelle obtained by the flocculation, and dehydrating at 300° C. for 1 h to obtain a graphene oxide/acrylonitrile butadiene rubber nanocomposite in which graphene oxide is 10 phr and the surfactant is 0.2 phr. Mixing the graphene oxide/acrylonitrile butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 160° C. during the optimum cure to obtain a graphene oxide/acrylonitrile butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 3, and Akron abrasion value of the vulcanizate is shown in Table 4. TABLE 3 Comparison between Mechanical Properties of Rubber Filled by Graphene Oxide and that of Rubber Filled by White Carbon Black Tensile Tensile Shore Strength at Strength at Scleroscope 100% 300% Tensile Tearing Hardness in Elongation/ Elongation/ Strength/ Elongation Tension Strength/ Sample A scale MPa MPa MPa at Break/% Set/% kN/m Contrast 2 65 1.9 6.2 18.5 557 16 44.6 Example 10 78 4.8 12.6 23.1 633 20 56.3 Contrast 3 54 1.2 4.8 23.9 638 28 36.8 Example 11 68 3.4 9.6 24.3 689 28 47.5 Contrast 4 67 2.1 6.9 19.1 534 20 49.3 Example 12 79 4.9 13.1 24.2 618 16 55.7 Contrast 5 58 1.7 5.2 22.9 723 32 37.9 Example 13 71 4.3 10.4 25.7 712 20 48.3 Contrast 6 69 2.3 8.4 17.6 469 20 46.3 Example 14 83 3.7 10.4 21.3 521 24 52.8 TABLE 4 Comparison between Akron Abrasion Values of Rubber Filled by Graphene Oxide and that of Rubber Filled by White Carbon Black Akron Abrasion Value/ Sample cm 3 /1.61 km Contrast 2 0.29 Example 10 0.13 Contrast 3 0.21 Example 11 0.11 Contrast 4 0.27 Example 12 0.12 Contrast 5 0.25 Example 13 0.10 Contrast 6 0.14 Example 14 0.08 Contrast 7 Adding a calcium chloride solution having a concentration of 1% to 500 g styrene butadiene latex (the solid content is 20 wt %) to perform flocculation; water washing a styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a styrene butadiene rubber flocculated gel. Mixing the styrene butadiene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (40 parts by weight of carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a styrene butadiene rubber vulcanizate. Properties of the styrene butadiene rubber vulcanizate are tested according to national standards. Data of mechanical properties of the styrene butadiene rubber vulcanizate are shown in Table 5, and air barrier performance of the styrene butadiene rubber vulcanizate is shown in Table 6. Example 15 Adding 20 g graphite oxide to 100 mL water, treating by ultrasonic waves for 5 h at a power of 2000 W, at a frequency of 1000 Hz, and at a temperature of 0° C. to obtain a graphene oxide/water sol having a solid content of 20 wt %. Mixing 25 g of the graphene oxide/water sol with 1 g carboxylic styrene butadiene latex (the solid content is 50 wt %) for 1 h at a power of 2000 W, at a frequency of 20000 Hz, and at a temperature of 0° C. to obtain a pretreated graphene oxide/water dispersion. Adding 500 g styrene butadiene latex (the solid content is 20 wt %) and further mixing for 1 h at a power of 2000 W, at a frequency of 20000 Hz, and at a temperature of 0° C. Adding a calcium chloride solution having a concentration of 1% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 80° C. for 24 h to obtain a graphene oxide/styrene butadiene rubber nanocomposite in which graphene oxide is 5 phr and the surfactant is 0.5 phr. Mixing the graphene oxide/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 5, and air barrier performance of the vulcanizate is shown in Table 6. Contrast 8 Adding a dilute sulphuric acid solution having a concentration of 10% to 167 g natural latex (the solid content is 60 wt %) to perform flocculation; water washing a styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 50° C. for 36 h to obtain a natural rubber flocculated gel. Mixing the natural rubber flocculated gel in a two roll rubber mixing mill according to a formulation (40 parts by weight of carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 143° C. during the optimum cure to obtain a natural rubber vulcanizate. Properties of the natural rubber vulcanizate are tested according to national standards. Data of mechanical properties of the natural rubber vulcanizate are shown in Table 5, and Akron abrasion value of the natural rubber vulcanizate is shown in Table 6. Example 16 Adding 5 g graphite oxide to 1 L water, treating by ultrasonic waves for 1 h at a power of 1000 W, at a frequency of 1000 Hz, and at a temperature of 100° C. to obtain a graphene oxide/water sol having a solid content of 0.5 wt %. Mixing 1000 g of the graphene oxide/water sol with 10 g natural epoxy latex (the solid content is 42 wt %) for 1 h at a power of 1000 W, at a frequency of 1000 Hz, and at a temperature of 100° C. to obtain a pretreated graphene oxide/water dispersion. Adding 167 g natural epoxy latex (the solid content is 60 wt %) and further mixing for 1 h at a power of 1000 W, at a frequency of 1000 Hz, and at a temperature of 0° C. Adding a dilute sulphuric acid solution having a concentration of 10% to perform flocculation. Water washing a graphene oxide/natural rubber micelle obtained by the flocculation, and dehydrating at 50° C. for 36 h to obtain a graphene oxide/natural rubber nanocomposite in which graphene oxide is 5 phr and the surfactant is 4.2 phr. Mixing the graphene oxide/natural rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 143° C. during the optimum cure to obtain a graphene oxide/natural rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 5, and air barrier performance of the vulcanizate is shown in Table 6. Contrast 9 Mixing 117 g natural latex (the solid content is 60 wt %) with 150 g styrene butadiene latex (the solid content is 20 wt %) and stirring. Adding a calcium sulphate solution having a concentration of 6% to perform flocculation; water washing a natural rubber/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 40° C. for 60 h to obtain a natural rubber/styrene butadiene rubber flocculated gel. Mixing the natural rubber/styrene butadiene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (40 parts by weight of carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 145° C. during the optimum cure to obtain a natural rubber/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 5, and air barrier performance of the vulcanizate is shown in Table 6. Example 17 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 3 h at a power of 600 W, at a frequency of 500 Hz, and at a temperature of 30° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 5000 g of the graphene oxide/water sol with 10 g KH550 for 1 h at a power of 600 W, at a frequency of 500 Hz, and at a temperature of 30° C. to obtain a pretreated graphene oxide/water dispersion. Adding 117 g natural latex (the solid content is 60 wt %) and 150 g styrene butadiene latex (the solid content is 20 wt %), and further mixing for 1 h at a power of 600 W, at a frequency of 500 Hz, and at a temperature of 30° C. Adding a calcium sulphate solution having a concentration of 6% to perform flocculation. Water washing a graphene oxide/natural rubber/styrene butadiene rubber micelle obtained by the flocculation, and dehydrating at 40° C. for 60 h to obtain a graphene oxide/natural rubber/styrene butadiene rubber nanocomposite in which graphene oxide is 5 phr and the surfactant is 10 phr. Mixing the graphene oxide/natural rubber/styrene butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/natural rubber/styrene butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 5, and air barrier performance of the vulcanizate is shown in Table 6. Contrast 10 Adding a calcium chloride solution having a concentration of 0.1% to 286 g chloroprene latex (the solid content is 35 wt %) to perform flocculation; water washing a chloroprene rubber micelle obtained by the flocculation, and dehydrating at 200° C. for 2 h to obtain a natural rubber/ethylene propylene rubber flocculated gel. Mixing the chloroprene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (40 parts by weight of carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 143° C. during the optimum cure to obtain a chloroprene rubber vulcanizate. Properties of the chloroprene rubber vulcanizate are tested according to national standards. Data of mechanical properties of the chloroprene rubber vulcanizate are shown in Table 5, and air barrier performance of the chloroprene rubber vulcanizate is shown in Table 6. Example 18 Adding 5 g graphite oxide to 50 L water, treating by ultrasonic waves for 10 min at a power of 10 W, at a frequency of 10 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.01 wt %. Mixing 50 kg of the graphene oxide/water sol with 10 g carboxylic chloroprene latex (the solid content is 38 wt %) for 10 min at a stirring speed of 10000 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 286 g chloroprene latex (the solid content is 35 wt %) and further mixing for 20 min at a stirring speed of 10000 r/min. Adding a calcium chloride solution having a concentration of 0.1% to perform flocculation. Water washing a graphene oxide/chloroprene rubber micelle obtained by the flocculation, and dehydrating at 200° C. for 2 h to obtain a graphene oxide/natural rubber/chloroprene rubber nanocomposite in which graphene oxide is 5 phr and the surfactant is 3.8 phr. Mixing the graphene oxide/chloroprene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 143° C. during the optimum cure to obtain a graphene oxide/chloroprene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 5, and air barrier performance of the vulcanizate is shown in Table 6. Contrast 11 Adding a sodium sulphate solution having a concentration of 5% to 400 g butyl latex (the solid content is 25 wt %) to perform flocculation; water washing an butyl rubber micelle obtained by the flocculation, and dehydrating at 120° C. for 6 h to obtain a butyl rubber flocculated gel. Mixing the butyl rubber flocculated gel in a two roll rubber mixing mill according to a formulation (40 parts by weight of carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a butyl rubber vulcanizate. Properties of the butyl rubber vulcanizate are tested according to national standards. Data of mechanical properties of the butyl rubber vulcanizate are shown in Table 5, and air barrier performance of the butyl rubber vulcanizate is shown in Table 6. Example 19 Adding 10 g graphite oxide to 0.5 L water, treating by ultrasonic waves for 1 h at a power of 200 W, at a frequency of 100 Hz, and at a temperature of 55° C. to obtain a graphene oxide/water sol having a solid content of 2 wt %. Mixing 250 kg of the graphene oxide/water sol with 10 g carboxylic butyl latex (the solid content is 20 wt %) for 1 h at a stirring speed of 900 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 400 g butyl latex (the solid content is 25 wt %) and further mixing for 1 h at a stirring speed of 900 r/min. Adding a sodium sulphate solution having a concentration of 5% to perform flocculation. Water washing a graphene oxide/butyl rubber micelle obtained by the flocculation, and dehydrating at 120° C. for 6 h to obtain a graphene oxide/butyl rubber nanocomposite in which graphene oxide is 5 phr and the surfactant is 2 phr. Mixing the graphene oxide/butyl rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/butyl rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 5, and air barrier performance of the vulcanizate is shown in Table 6. Contrast 12 Mixing 350 g styrene butadiene latex (the solid content is 20 wt %) with 50 g butadiene latex (the solid content is 40 wt %) and stirring. Adding a sodium sulphate solution having a concentration of 6% to perform flocculation; water washing a styrene butadiene rubber/butadiene rubber micelle obtained by the flocculation, and dehydrating at 200° C. for 1 h to obtain a styrene butadiene rubber/butadiene rubber flocculated gel. Mixing the styrene butadiene rubber/butadiene rubber flocculated gel in a two roll rubber mixing mill according to a formulation (40 parts by weight of carbon black, 5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a styrene butadiene rubber/butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 5, and air barrier performance of the vulcanizate is shown in Table 6. Example 20 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 3 h at a power of 600 W, at a frequency of 500 Hz, and at a temperature of 30° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 5000 g of the graphene oxide/water sol with 10 g butadiene-vinylpyridine latex (the solid content is 40 wt %) for 30 min at a stirring speed of 1000 r/min to obtain a pretreated graphene oxide/water dispersion. Adding 350 g butadiene-vinylpyridine latex (the solid content is 20 wt %) and 50 g butadiene latex (the solid content is 40 wt %), and further mixing for 3 h at a stirring speed of 1000 r/min. Adding a calcium sulphate solution having a concentration of 6% to perform flocculation. Water washing a graphene oxide/styrene butadiene rubber/butadiene rubber micelle obtained by the flocculation, and dehydrating at 200° C. for 1 h to obtain a graphene oxide/styrene butadiene rubber/butadiene rubber nanocomposite in which graphene oxide is 5 phr and the surfactant is 4 phr. Mixing the graphene oxide/styrene butadiene rubber/butadiene rubber nanocomposite in a two roll rubber mixing mill according to a formulation (5 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 1.5 parts by weight of accelerator CZ, 0.2 parts by weight of accelerator M, 2 parts by weight of antioxidant 4010NA, and 2.5 parts by weight of sulfur) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure to obtain a graphene oxide/styrene butadiene rubber/butadiene rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 5, and air barrier performance of the vulcanizate is shown in Table 6. TABLE 5 Comparison between Mechanical Properties of Rubber Filled by Graphene Oxide and that of Rubber Filled by Carbon Black Tensile Tensile Shore Strength at Strength at Scleroscope 100% 300% Tensile Tearing Hardness in Elongation/ Elongation/ Strength/ Elongation Tension Strength/ Sample A scale MPa MPa MPa at Break/% Set/% kN/m Contrast 7 67 2.1 5.9 19.5 517 20 46.4 Example 15 75 4.2 11.6 17.9 610 28 51.3 Contrast 8 59 1.7 5.3 24.4 567 28 41.8 Example 16 65 2.5 8.7 21.6 619 32 42.5 Contrast 9 70 2.2 7.2 19.8 512 20 50.3 Example 17 72 3.2 11.3 21.2 597 24 51.7 Contrast 10 62 1.9 4.9 23.7 623 28 38.3 Example 18 66 3.4 9.6 22.7 683 32 41.3 Contrast 11 65 2.5 9.4 18.1 444 20 45.5 Example 19 72 2.7 10.0 19.2 508 24 47.8 Contrast 12 71 2.3 8.6 17.5 512 16 47.3 Example 20 74 2.9 9.1 17.1 641 24 49.1 TABLE 6 Comparison between Air Barrier Performance of Rubber Filled by Graphene Oxide and that of Rubber Filled by Carbon Black Air Barrier Performance/ Sample 10 −17 m 2 s −1 Pa −1 Contrast 7 4.52 Example 15 2.43 Contrast 8 3.17 Example 16 2.01 Contrast 9 3.89 Example 17 2.14 Contrast 10 1.38 Example 18 0.47 Contrast 11 1.47 Example 19 0.51 Contrast 12 2.64 Example 20 1.03 Contrast 13 Adding 250 g polyurethane emulsion (the solid content is 40 wt %) to a spray drier and performing spray drying. The drying medium is hot air having a temperature of 200° C. Collecting the product after drying to obtain polyurethane powder. Moulding the polyurethane powder to obtain a polyurethane rubber vulcanizate. Properties of the polyurethane rubber vulcanizate are tested according to the national standards. Data of mechanical properties of the polyurethane rubber vulcanizate are shown in Table 7. Example 21 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 100 g of the graphene oxide/water sol with 250 g polyurethane emulsion (the solid content is 55 wt %) for 20 min at a stirring speed of 800 r/min. Transferring the compounding emulsion of graphene oxide/polyurethane emulsion into a spray drier, and performing spray drying. The drying medium is hot air having a temperature of 200° C. Collecting the product after drying to obtain a graphene oxide/polyurethane nanocomposite in which graphene oxide is 0.1 phr. Moulding the graphene oxide/polyurethane nanocomposite to obtain a graphene oxide/polyurethane vulcanizate. Properties of the vulcanizate are tested according to the national standards. Data of mechanical properties of the vulcanizate are shown in Table 7. Example 22 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 1000 g of the graphene oxide/water sol with 250 g polyurethane emulsion (the solid content is 55 wt %) for 20 min at a stirring speed of 800 r/min. Transferring the compounding emulsion of graphene oxide/polyurethane emulsion into a spray drier, and performing spray drying. The drying medium is hot air having a temperature of 200° C. Collecting the product after drying to obtain a graphene oxide/polyurethane nanocomposite in which graphene oxide is 1 phr. Moulding the graphene oxide/polyurethane nanocomposite to obtain a graphene oxide/polyurethane vulcanizate. Properties of the vulcanizate are tested according to the national standards. Data of mechanical properties of the vulcanizate are shown in Table 7. Example 23 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 5000 g of the graphene oxide/water sol with 250 g polyurethane emulsion (the solid content is 55 wt %) for 20 min at a stirring speed of 800 r/min. Transferring the compounding emulsion of graphene oxide/polyurethane emulsion into a spray drier, and performing spray drying. The drying medium is hot air having a temperature of 200° C. Collecting the product after drying to obtain a graphene oxide/polyurethane nanocomposite in which graphene oxide is 5 phr. Moulding the graphene oxide/polyurethane nanocomposite to obtain a graphene oxide/polyurethane vulcanizate. Properties of the vulcanizate are tested according to the national standards. Data of mechanical properties of the vulcanizate are shown in Table 7. Example 24 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 10000 g of the graphene oxide/water sol with 250 g polyurethane emulsion (the solid content is 55 wt %) for 20 min at a stirring speed of 800 r/min. Transferring the compounding emulsion of graphene oxide/polyurethane emulsion into a spray drier, and performing spray drying. The drying medium is hot air having a temperature of 200° C. Collecting the product after drying to obtain a graphene oxide/polyurethane nanocomposite in which graphene oxide is 10 phr. Moulding the graphene oxide/polyurethane nanocomposite to obtain a graphene oxide/polyurethane vulcanizate. Properties of the vulcanizate are tested according to the national standards. Data of mechanical properties of the vulcanizate are shown in Table 7. Example 25 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 20000 g of the graphene oxide/water sol with 250 g polyurethane emulsion (the solid content is 55 wt %) for 20 min at a stirring speed of 800 r/min. Transferring the compounding emulsion of graphene oxide/polyurethane emulsion into a spray drier, and performing spray drying. The drying medium is hot air having a temperature of 200° C. Collecting the product after drying to obtain a graphene oxide/polyurethane nanocomposite in which graphene oxide is 20 phr. Moulding the graphene oxide/polyurethane nanocomposite to obtain a graphene oxide/polyurethane vulcanizate. Properties of the vulcanizate are tested according to the national standards. Data of mechanical properties of the vulcanizate are shown in Table 7. Example 26 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 40000 g of the graphene oxide/water sol with 250 g polyurethane emulsion (the solid content is 55 wt %) for 20 min at a stirring speed of 800 r/min. Transferring the compounding emulsion of graphene oxide/polyurethane emulsion into a spray drier, and performing spray drying. The drying medium is hot air having a temperature of 200° C. Collecting the product after drying to obtain a graphene oxide/polyurethane nanocomposite in which graphene oxide is 40 phr. Moulding the graphene oxide/polyurethane nanocomposite to obtain a graphene oxide/polyurethane vulcanizate. Properties of the vulcanizate are tested according to the national standards. Data of mechanical properties of the vulcanizate are shown in Table 7. TABLE 7 Mechanical Properties of Graphene Oxide/Polyurethane Vulcanizate Made by Emulsion Compounding with Spray Drying Process Tensile Shore Strength at Scleroscope Tensile Elongation at 100% Hardness in D Strength/ Break/ Elongation/ Sample scale MPa % MPa Contrast 13 74 27.1 156 25.9 Example 21 78 23.5 65 — Example 22 80 26.3 61 — Example 23 82 26.7 64 — Example 24 87 26.5 56 — Example 25 90 27.1 45 — Example 26 92 27.6 44 — Example 27 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 5000 g of the graphene oxide/water sol with 167 g silicone rubber latex (the solid content is 60 wt %) for 30 min at a stirring speed of 800 r/min. Transferring the compounding emulsion of graphene oxide/silicone rubber latex into a spray drier, and performing spray drying. The drying medium is hot air having a temperature of 60° C., and the carrier gas contains 1% by flow ratio of HCl gas. Collecting the product after drying to obtain a graphene oxide/silicone rubber nanocomposite in which graphene oxide is 5 phr. Moulding the graphene oxide/silicone rubber nanocomposite to obtain a graphene oxide/silicone rubber vulcanizate, mixing according to a formulation (2 parts by weight of DCP) to obtain a mix gel. Vulcanizing the mix gel at 170° C. during the optimum cure, and further vulcanizing in an oven for 2 h at 200° C. to obtain a graphene oxide/silicone rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 8. Example 28 Adding 10 g graphite oxide to 10 L water, treating by ultrasonic waves for 2 h at a power of 800 W, at a frequency of 1000 Hz, and at a temperature of 25° C. to obtain a graphene oxide/water sol having a solid content of 0.1 wt %. Mixing 5000 g of the graphene oxide/water sol with 200 g fluorine rubber latex (the solid content is 50 wt %) for 30 min at a stirring speed of 800 r/min. Transferring the compounding emulsion of graphene oxide/silicone rubber latex into a spray drier, and performing spray drying. The drying medium is hot air having a temperature of 300° C., and the carrier gas contains 1% by flow ratio of HCl gas. Collecting the product after drying to obtain a graphene oxide/fluorine rubber nanocomposite in which graphene oxide is 5 phr. Moulding the graphene oxide/fluorine rubber nanocomposite to obtain a graphene oxide/fluorine rubber vulcanizate, mixing according to a formulation (2 parts by weight of DCP) to obtain a mix gel. Vulcanizing the mix gel at 150° C. during the optimum cure, and further vulcanizing in an oven for 24 h at 204° C. to obtain a graphene oxide/fluorine rubber vulcanizate. Properties of the vulcanizate are tested according to national standards. Data of mechanical properties of the vulcanizate are shown in Table 8. TABLE 8 Mechanical Properties of Graphene Oxide/Rubber Vulcanizate Made by Emulsion Compounding with Spray Drying Process Tensile Tensile Shore Strength at Strength at Scleroscope 100% 300% Tensile Tearing Hardness in Elongation/ Elongation/ Strength/ Elongation Tension Strength/ Sample A scale MPa MPa MPa at Break/% Set/% kN/m Example 27 65 5.7 9.8 16.2 458 12 46.4 Example 28 72 6.9 10.5 18.9 420 8 51.3 While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

A process for preparing a completely delaminated graphene oxide/rubber nanocomposite. The process combines emulsion compounding with flocculation or spray drying, retains the morphology of graphene oxide/rubber composite in a liquid state, and achieves highly dispersed and highly delaminated morphology dispersed on nano scale. Furthermore, a substance able to produce ionic bonding or chemical bonding with the surface functional groups of graphene oxide is added to graphene oxide/hydrosol, as a surfactant, thus the interfacial bonding between graphene oxide and the rubber is increased. The composite is subjected to subsequent compounding and vulcanization to prepare a vulcanizate with dynamic performance, such as a high tensile strength, stress at a definite elongation, tearing strength, etc.

[0001] This Application is a Continuation of currently pending PCT/IB2010/050784 filed Feb. 23, 2010, which Application claims priority of Spanish Patent Application P200900505 filed Feb. 24, 2009. FIELD OF THE INVENTION [0002] The present invention relates to a method for reducing interstitial elements in cast alloys. Specifically, it relates to a method for reducing hydrogen in steel castings. The present invention also relates to a system for performing this method, which can be integrated into a mold or a continuous casting system. BACKGROUND OF THE INVENTION [0003] Throughout this document, the term interstitial elements refers to those atoms that, because of their small size with respect to the main elements in the alloy, are able to diffuse interstitially, that is, via the spaces in the metallic crystalline lattice, without the need to displace other atoms from their positions in the lattice. In the case of many alloys, like steel, atoms like hydrogen, nitrogen carbon and others can act like interstitial elements. [0004] It is known that hydrogen is an interstitial element that can cause the embrittlement of steel components. Specifically, the sensitivity to hydrogen embrittlement is more evident in high-strength alloys. [0005] Various mechanisms have been described as responsible for said embrittlement. These mechanisms do not begin to materialize as long as the temperature does not drop below a given threshold so that the interstitial elements in question feature a reduced mobility and an insufficient solubility, and tend to combine with other elements to form embrittling compounds. [0006] It is known that hydrogen features a solubility which varies from one metallurgical phase to another and at the same time, solubility increases within each phase as temperature increases. For example, in the case of the solid phases of steel, hydrogen solubility ranges between 8 ppm in high temperature austenite (1400° C.), and less than 1 ppm in room temperature ferrite, and it is approximately 30 ppm in the liquid phase at 1600° C. [0007] It can be considered that the phenomenon of diffusion of interstitial elements is governed mainly by the interstitial atom's thermal agitation within the crystalline lattice, i.e., at higher temperatures, greater thermal agitation and, therefore, greater probability of diffusion. Although the situation usually considered is the diffusional flux occurring from high concentration regions towards regions of lower concentration this is not the only possible scenario. Rigorously, the driving force behind diffusional fluxes is the free energy reduction of the system. To be still more precise, diffusion occurs from areas of high chemical potential to areas of lower chemical potential. [0008] Nevertheless, it can be shown that whenever the atomic mobility is sufficient, and in absence of composition differences or other factors which could cause a more important flux, a high temperature gradient also causes a net flux of interstitial elements towards higher temperature regions. This effect is produced because, on the one hand, as regions at higher temperature are in a state of lower saturation, as they feature greater solubility, and therefore they would have a lower chemical potential than regions at higher saturation in the same temperature conditions. On the other hand, the flux towards high temperature regions is encouraged by the increase in atomic mobility as the temperature increases. [0009] The presence of hydrogen in metallic alloys, especially in steels, is due to several reasons, from the presence of humidity in the raw materials or equipment or the decomposition of compounds present in the later, as well as actions performed during the alloy casting and refining process, for example those where hydrogen is blown through the molten metal with the aim of eliminating other elements, with the final consequence that some fraction of the hydrogen used remains dissolved in the molten metal. [0010] During the casting process, heat extraction from the metal occurs through the walls of the mold and from the free surfaces of the cast metal. [0011] In this manner, the cast metal generally cools from the surface to the core of the casting. That is, the casting's core remains at higher temperature than its surface, producing an increasing temperature gradient from the surface towards the core. [0012] This marked temperature gradient, at temperatures at which interstitial elements such as hydrogen still feature a high mobility, produces a flux of interstitial elements towards the casting core, due to its higher temperature and greater capacity to dissolve said elements with respect to the adjacent regions which are at lower temperatures. [0013] This diffusive flux tends to concentrate the total content of the interstitial element in question in the core region of the casting. [0014] Due to the damaging effect of hydrogen in the mechanical properties of the components produced, traditionally different systems have been used to eliminate it. [0015] These systems can be divided into two families: The use of certain additions during the refining process or the exposure of the molten metal to a reduced pressure. [0016] The first of these methods consists in the addition of refining elements or substances that would combine with hydrogen (or other elements) and form insoluble substances that could be then eliminated during the refining process. [0017] The second system consists in exposing the molten metal to an atmosphere with reduced pressure, as hydrogen solubility in the molten metal is function of pressure as well as of temperature and crystalline structure. [0018] This second system produces a better hydrogen elimination rate, although at the expense of a large increase in the investment for the necessary equipment. For its part, the first system entails a much smaller investment, but it has also a lower hydrogen reduction rate, so that it is much less effective. Furthermore, this first system has the added issue that implies the modification of the alloy composition. [0019] Therefore, the need is clear for a method which reduces interstitial elements, particularly hydrogen, in a casting process, without the modification of the alloy composition (with the exception of interstitial elements themselves) and furthermore, without requiring a large investment such as in the case of vacuum casting and refining. BRIEF SUMMARY OF THE INVENTION [0020] The previously discussed drawbacks are resolved by the method and the system of the invention, featuring other advantages which will be described below. [0021] According to one aspect, the method for reducing interstitial elements in alloy castings of the present invention comprises the steps of: injecting said alloy in a system for the formation of a casting or a continuous cast; allowing said alloy to cool; wherein at least a peripheral region of the casting is heated, so that the flux of interstitial elements occurs towards at least one the peripheral region. [0025] Consequence of this feature, a method is achieved where most of the interstitial elements concentrate in one or several regions in the surface region of the casting. Later on, such elements can easily be eliminated from these regions by means of a thermal surface treatment or surface machining of the casting. [0026] Preferably, at least one peripheral region is heated before the alloy cools to a temperature low enough for the formation of embrittling compounds. [0027] According to another aspect of the invention, at least one peripheral region is heated at a temperature between 900° C. and the melting point of the alloy. [0028] Such heating of each peripheral region is preferably maintained until any part of the piece, different than the peripheral regions, is at a temperature of less than 400° C. [0029] According to a further aspect of the invention, the interstitial elements are hydrogen, carbon, nitrogen, boron, argon, or other interstitial elements or other elements which feature high diffusivity in the alloy matrix, and said alloy is a steel alloy, iron, copper, nickel, titanium, cobalt, chrome or others with melting points greater than 800° C., as well as some alloys with lower melting points, such as aluminium alloys. [0030] According to still another aspect of the invention, the system for reducing interstitial elements in cast alloys comprises at least one heating element situated on the periphery of the cast. [0031] According to still a further aspect of the invention, each heating element is an electric resistor or an induction coil, and each heating element is complemented with a temperature sensor. [0032] According to sill another aspect, the complete system of the invention can be applied both to mold casting and continuous casting systems. BRIEF DESCRIPTION OF THE DRAWINGS [0033] The foregoing summary as well as the following detailed description of the invention will be best understood when considered in conjunction with the accompanying drawings, and wherein: [0034] FIGS. 1 and 2 are schematic views of a casting system according to the present invention, representing the flux of interstitial elements and the isothermal curves in the cast alloy; and [0035] FIG. 3 is a schematic view of a continuous casting system according to the present invention. DETAILED DESCRIPTION OF THE INVENTION [0036] It should be noted that although the present description corresponds to the case of hydrogen reduction during steel casting, the scope of application of the method of the present invention extends to any alloy casting wherein a reduction in the amount of dissolved hydrogen or of any other interstitial element is desired, such as, for example, carbon, nitrogen, boron and others. [0037] Unlike the method of the previously described techniques, according to the method of the present invention the existence of a increasing temperature gradient is forced and directed towards one or more points on the surface of the piece, so that the flux of interstitial elements occurs towards the surface, instead of towards the core of the casting. [0038] In this way, the interstitial elements will be eliminated from the casting by simple diffusion through the surface of the piece, and any remainder concentrates in a region close to the surface, so that it can easily be eliminated by means of a subsequent thermal surface treatment and/or surface machining of the casting. [0039] In order to obtain a temperature gradient favourable to force the interstitial element flux towards the surface of the casting, it is necessary to maintain at least one region of the surface of the casting at a sufficiently high temperature during the solidification and cooling process, so that it is maintained at a higher temperature than the rest of the casting till the end of the process. [0040] In the event of wanting to eliminate an element such as hydrogen, which tends to combine with other atoms, forming embrittling compounds, it is important to ensure that this method is initiated before the piece cools to temperatures at which said embrittling compound formation reactions occur. [0041] As observed in the figures, the system, in this case a mold, indicated generally by means of the numeric reference 1 , comprises a heating element 2 . [0042] It must be pointed out that even though one heating element 2 has been represented in the figures for the sake of simplicity, it is clear that there can be any suitable number of heating elements, depending on the shape and dimensions of the mold. [0043] The or each heating element 2 , which is integrated into the mold wall 1 and begins to actuate during the pouring of the molten alloy into the mold, can consist of an induction coil, duly protected from the liquid metal, or of an electric resistor, or any suitable heating element. [0044] One requirement of this heating element is that it must be built into the mold, at a distance which is sufficiently close to the inner surface of the mold and which reliably permits the region of the surface of the piece to be kept at a suitable temperature. [0045] Another essential requirement of the heating element is its capacity to endure temperatures higher than that of the alloy's melting point, and especially the thermal shock produced during the filling of the mold. [0046] For example, in the event of treating cast steel pieces, the temperature to be maintained can exceed 1400° C., and the temperature of the molten metal can exceed 1600° C. [0047] In the event that an electric resistor is used as a heating element, this can be built integrated into the wall of the mold, surrounded and protected for example by an alloy resistant to the temperature, or ceramic refractory material, or even integrated into the wall of the mold in the case of sand casting. [0048] Heating elements using an electric resistor are expected to be tougher and less expensive, and might require a simpler control system, than in the case of an induction coil, although they feature a larger heat lag. [0049] If the heating element is realised using an induction coil, the surrounding material must not be conductive in order to prevent the generation of induced currents, since these induced currents would heat the heating element or the walls of the mold, instead of the surface of the casting. [0050] Each heating element 2 is connected to a temperature sensor 3 , a control system 4 and an energy supply system 5 . [0051] The control system 4 is required to adjust the temperature of the heated peripheral region (or hot spot) and could be similar to those normally used for automated surface induction heat treatments. [0052] Additionally, the type and the placement of the temperature sensor 3 must be suitable to prevent the magnetic field generated by the induction coil from distorting the temperature measurement, and this must be situated so that it directly measures the temperature of the surface of the casting. [0053] In this sense, a heating element 2 based on an induction coil it is expected to require a slightly greater investment than that based on a resistor, but has the advantage that it permits a much quicker and precise modulation of the temperature obtained. [0054] An alternative embodiment to mold 1 of FIG. 1 has been represented in FIG. 3 , which depicts the application of he method to a continuous casting system. In this embodiment, the same numeric references have been maintained to identify elements equivalent to those in the previous embodiment. [0055] A continuous casting system 10 , whose main functioning is identical to that of the mold 1 , is represented in FIG. 3 . [0056] In this case, the molten metal is deposited in a distribution tank 11 , wherefrom it forms a cast bar 12 by means of a cooled ingot mold 13 . [0057] At the outlet of the ingot mold 13 , the cast bar 12 is cooled on one side by means of a cooling section 14 , while the heating elements 2 are situated in contact with one of the surfaces of the cast bar 12 . Its ideal arrangement is next to the outlet of the ingot mold 13 and along the section of the refrigeration 14 on its opposite side. [0058] The cast bar 12 can be cooled with water jets or spray, as it is conventional practice, although protecting from said cooling process the side where the heat is applied for the elimination of the interstitial elements (the heated peripheral region or hot spot). [0059] Table 1 contains some examples of the range of temperatures implied in the method of the present invention, for different alloys. [0060] It must be pointed out that the temperature whereat the peripheral regions of the mold have to be maintained have to be as high as possible from a practical point of view, but comfortably less than the melting point of the alloy. [0000] TABLE 1 Illustrative values, for different alloys, of the melting temperature, the temperature at which hot spots on the surface of the casting should be kept at and the critical core temperature. Hot spot Critical Alloy Melting point temperature temperature Low C steel 1750° C. 1000° C.-1700° C. 400° C. High C steel 1580° C. 1000° C.-1500° C. 400° C. Alloy steel 1700° C. 1000° C.-1600° C. 400° C. Cast iron 1400° C. 1000° C.-1350° C. 400° C. Copper 1350° C.  900° C.-1300° C. 400° C. Nickel alloys 1550° C.-1700° C. 1000° C.-1600° C. 400° C. [0061] Regarding the holding time necessary at each heated peripheral region or hot spot, this time at temperature depends on the volume and the geometry of the casting in question. Nevertheless, it must be stressed the importance that the heating elements produce the hot spots on the surface of the casting must be active from the moment when the mold is filled. These hot spots must also be held at the suitable temperature until the temperature of the core of the casting has decreased below a critical temperature (approximately 400° C.). [0062] Once the core reaches such said critical temperature, the power applied to the heating element can be slowly reduced, always guaranteeing that the hot spot is at a higher temperature than the core regions of the casting, until both are below the critical temperature. The time necessary to cool the core below the critical temperature can be estimated from some simple modelling of mold and casting cooling. [0063] Despite having referred to a specific embodiment of the invention, it is clear for a person skilled in the art that the method and the mold disclosed can undergo numerous variations and modifications, and that all of the mentioned details can be substituted for other technically equivalent details, without departure from the scope of protection defined by the attached claims. [0064] For example, possible modifications can be as follows: instead of using a temperature measurement system, the control system can be managed by other means (for example, simply by determining, via modelling or experimentally the holding time necessary for each hot spot(s) to produce the right effect and setting their heating time accordingly); the heat applied to the surface of the casting do not need to be continuous, but followed a suitable function, with varying intensity; the surface heating of the surface of the casting is maintained until the core temperature drops below 400° C.; the interstitial elements do not need only to be diffused to the region below the surface where the heating is being applied, but due to the proximity of such surface, a fraction of such interstitial elements could diffuse out of the metal (desorption) and, therefore, obtaining their elimination from the casting; and the heating elements could be implemented either integrated in the mold walls, or as removable attachments associated therewith.

The method for reducing interstitial elements in alloy castings which comprises the following steps: pouring the alloy for the formation of a casting; and allowing said alloy to cool. According to the method, at least a peripheral region of the casting is heated, so that the flux of interstitial elements is caused towards the at least one peripheral region. The method is achieved where most of the interstitial elements concentrate in at least one region in the surface region of the casting. At later stages these elements can be easily eliminated from the respective regions by means of a thermal surface treatment or surface machining of the casting.

BACKGROUND OF THE INVENTION [0001] The invention relates to a transmission coil which is configured to inductively transfer energy, comprising a carrier, a coil arrangement with a multiplicity of turns, and a capacitance which forms, together with the coil arrangement, an oscillatory circuit. Further aspects of the invention relate to a fixed charging station and to a vehicle, each comprising such a transmission coil, and to a system for inductively charging vehicles comprising a fixed charging station and a vehicle. [0002] Various systems for the contactless transfer of energy are known for conveniently charging electrical energy stores. Depending on the configuration, these systems can be used, for example, for charging consumer electronics such as, for example, cell phones or MP3 players or for charging electrically driven vehicles. Electrically driven vehicles comprise, for example, industrial trucks which are used for transporting goods in a warehouse, hybrid vehicles which have both an electric drive and an internal combustion engine, and purely electrically powered motor vehicles. [0003] DE 20 2011 077 709 A1 discloses an arrangement for transmitting electrical energy, in particular for charging an energy store of a mobile carrier, in particular of a motor vehicle. The arrangement comprises an electromagnetic transmission unit which is formed by two transmission elements which are embodied as coils. One of the coils is assigned here to the motor vehicle, and the other is assigned to a charging station. Each coil is assigned a capacitor, wherein in each case a capacitor with a coil forms a resonant circuit. Furthermore, the arrangement comprises rectifiers, power inverters and a PFC (Power Factor Correction) circuit. The PFC circuit permits, inter alia, reactive power to be compensated. Using the reactive power compensation, it is also possible to transmit the energy with a high level of efficiency even in the case of a relatively weak inductive coupling. [0004] A disadvantage of the prior art is that in addition to the transmission coils a multiplicity of separate components are also required. SUMMARY OF THE INVENTION [0005] A transmission coil is proposed which is configured to inductively transfer energy, comprising a carrier, a coil arrangement with a multiplicity of turns, and a capacitance. There is provision here that the capacitance is formed by a multiplicity of capacitors, wherein each capacitor is assigned to an individual turn or a group of at least two turns of the coil arrangement, and the capacitors are arranged, together with the coil arrangement, on the carrier. [0006] Transmission coils are required for the inductive transmission of electrical energy, wherein a primary transmission coil is arranged in a charging station, and a secondary transmission coil is assigned to a mobile energy store which is to be charged. In order to transmit energy, the primary coil is excited with an alternating voltage, as a result of which an alternating magnetic field is produced in the region of the primary transmission coil. If the secondary transmission coil is moved into the vicinity of the primary transmission coil, with the result that the magnetic field of the primary transmission coil flows through said secondary transmission coil, an electric current is induced in the secondary transmission coil. [0007] For an efficient transmission of energy, oscillatory circuits are formed from a coil arrangement with a multiplicity of turns and a capacitance. The oscillatory circuit is excited with an alternating voltage which is generated by power electronics. In this context, it has been customary hitherto that the power electronics and the capacitance which is necessary to form the oscillatory circuit are arranged spatially separate from the coil arrangement. In this context, the capacitance is usually formed by one or a small number of capacitors with a high capacitance and is assigned in its entirety to the coil arrangement. [0008] In contrast, in the case of the transmission coil according to the invention there is provision to use a multiplicity of capacitors instead of a single capacitance which is assigned to the entire coil arrangement, wherein each capacitor is assigned to an individual turn or to a group of at least two turns of the coil arrangement. In the case of turns which are combined to form groups, the coil arrangement comprises a multiplicity of such groups. In this context, each individual capacitor or each individual capacitance is, considered per se, respectively considerably smaller than the entire capacitance assigned to the coil arrangement. As a result, the installation space which is required for each individual capacitor of the capacitors also turns out to be significantly smaller, which permits the individual capacitors to be arranged jointly on a carrier, together with the coil arrangement. [0009] The carrier holds both the coil arrangement and the capacitors which are assigned to the individual turns or groups of turns and secures them mechanically. The carrier is preferably embodied as a metal plate whose external shape essentially follows the shape of the coil arrangement. A metal such as, for example, aluminum is preferably used as the material, wherein the turns of the coil arrangement are electrically insulated from the carrier. [0010] A group of turns usually comprises between 2 and 20 turns, and the entire coil arrangement usually comprises between 4 and 200, preferably between 10 and 100 turns. [0011] In a further embodiment of the invention, there is also provision that, furthermore, power electronics, which comprise a power inverter and/or a rectifier and/or further circuit components (e.g. microcontroller for controlling the charging sequence), are arranged on the carrier. [0012] In this embodiment, all of the components which are required for the transmission of energy are integrated together with the respective transmission coil to form one unit. If a transmission coil is embodied, for example, as a primary transmission coil, in particular a rectifier, a power inverter, the coil arrangement with the multiplicity of turns as well as the capacitors which are assigned to the individual turns or individual groups of turns are arranged on the carrier. [0013] If the transmission coil is embodied as a secondary transmission coil, for example a rectifier, the coil arrangement with the multiplicity of turns or groups or turns and the respective capacitors are arranged on the carrier. [0014] The transmission coil according to the invention requires no further external components for its operation. The primary transmission coil only then needs to be connected to a power supply system for the supply of energy. The secondary transmission coil then only needs to be connected to the electric energy store which is to be charged. [0015] In one variant of the transmission coil according to the invention, the power electronics are configured to deactivate or activate individual turns or individual groups of turns of the coil arrangement. [0016] Since each individual turn of the coil arrangement or each group of turns is assigned a separate capacitance in the form of a capacitor, each turn or group of turns constitutes, considered per se, an independent oscillatory circuit. This permits individual turns or groups of turns to be deactivated, and not included in the transmission of energy, without further compensating measures. This can be utilized, for example, to influence the shape of the magnetic field generated by the transmission coil or to produce various turn conditions. [0017] In one embodiment of the invention, the turns of the coil arrangement are arranged in the form of concentric circles or a spiral path on the carrier. A rectangular or square embodiment of the turns is also conceivable. In this context, the power electronics and/or the capacitors are preferably located in the center of the coil arrangement. Such an arrangement permits an extremely compact design of the transmission coil. [0018] In one embodiment of the invention, the carrier is configured to serve as a shield for the electromagnetic compatibility (EMC). [0019] In the power electronics, in particular in the case of a power inverter, alternating magnetic fields are produced which have to be shielded in order to avoid adversely affecting radio transmissions in the surroundings and the functioning of other electronic devices in the surroundings and in order to comply with legal requirements for the protection of persons against magnetic fields. An electrically conductive material is required for the shielding. If, for example, the carrier is configured in such a way that it surrounds the coil arrangement and the power electronics and the carrier is also fabricated from an electrically conductive material such as, for example, aluminum, the carrier can shield electromagnetic radiation which is produced. [0020] In a further embodiment of the transmission coil, the carrier is configured in such a way that it serves as a heat sink for the capacitors and/or for the power electronics. For this purpose, a material which has good thermal conductivity is preferably selected for the carrier. Therefore, in particular aluminum and copper are suitable as materials, wherein aluminum is more cost-effective than copper and is therefore preferred. [0021] In a further embodiment of the transmission coil there is provision that the carrier comprises ducts which are configured to have a cooling medium flowing through them. The cooling medium which is used can be, for example, a water-glycol mixture. Such an embodiment of the carrier is suitable, in particular, for conducting away the waste heat of the power electronics and of the capacitors. However excessive heating of the turns of the coil arrangement can also be avoided in this way. [0022] In one embodiment of the transmission coil, said coil comprises more than one coil arrangement. In particular, the transmission coil can comprise two coil arrangements. In this context, the two coil arrangements can be connected to one another in such a way that the turns are connected in the same direction or in opposite directions. [0023] A further aspect of the invention is making available a fixed charging station which is configured to charge vehicles in a wireless fashion, wherein the charging station comprises at least one or precisely one of the transmission coils described herein as a primary transmission coil. [0024] Furthermore, a vehicle is made available which is configured to charge in a wireless fashion, wherein the vehicle comprises at least one or precisely one of the transmission coils described herein as a secondary transmission coil. The vehicle represents a mobile unit which can interact with a charging station. [0025] Furthermore, a system is made available for inductively charging vehicles, which system is formed by a fixed charging station and a vehicle, wherein both the charging station and the vehicle comprise at least one or precisely one of the described transmission coils. In this context, in the system there is provision that the secondary transmission coil of the vehicle is moved temporarily into the vicinity of the primary transmission coil of the charging station, with the result that the magnetic field which is generated by the primary transmission coil flows through the secondary transmission coil. After the ending of the charging process, the vehicle can exit the charging station again, as a result of which the secondary transmission coil is removed from the region of the primary transmission coil. [0026] The transmission coil is not limited to the use in conjunction with the inductive charging of vehicles. Depending on the configuration of the transmission coil, said coil can be used, in particular, to charge any mobile units with an energy store. Examples of this are the wireless charging of cell phones or of electrically powered tools. In this context, a primary transmission coil is assigned to a charging unit, and a secondary transmission coil is assigned to the mobile unit. [0027] In the systems known from the prior art, the charging station and the mobile unit which interacts with the charging station comprise a multiplicity of separate discrete assemblies. In the case of the mobile unit which contains the secondary transmission coil, these are the coil arrangement, the capacitance, the rectifier and a radiator. In this context, every component must satisfy per se all the requirements made, for example, of the cooling or the shielding for the electromagnetic compatibility (EMC), as a result of which redundancies occur. These redundancies are avoided with the measures of the invention by means of a fully integrated design in which the transmission coil comprises, in addition to the coil arrangement, also the necessary capacitances and, if appropriate, the necessary power electronics, and in which the coil arrangement, the capacitance and, if appropriate, the necessary power electronics are arranged together on a carrier. This commonly used carrier equally satisfies the function of a mechanical carrier, of a shield and of a radiator for all the components which are accommodated. As a result, there is a saving in material without a restriction of the functionality, which reduces the required installation space, the weight and the costs of the transmission coil. [0028] In addition there is provision to use, instead of a single capacitance which is assigned to the entire coil arrangement, a plurality of capacitors which are each assigned to an individual turn of the coil arrangement or to a group of turns of the coil arrangement. In this context, each turn or each group of turns is compensated individually by the respectively assigned capacitor. This permits, when necessary, individual turns or groups of turns to be deactivated without the need to perform additional measures to adapt the oscillatory circuit. Such deactivation of individual turns or of individual groups of turns permits, for example, the magnetic field generated by the primary transmission coil to be changed and to be adapted in optimum way to the respectively used secondary transmission coil or different turn conditions to be produced. [0029] Furthermore, the compensation of individual turns or groups of turns provides the advantage that the maximum resonant voltages which occur can be significantly reduced. As a result, the expenditure on insulation and shielding can be lowered. [0030] In addition, the arrangement of all the relevant components of a transmission coil on a common carrier facilitates the cooling. Only the common carrier then has to be cooled, and this is possible, for example, with liquid cooling or with air cooling. Moreover, by integrating all the relevant components it is possible to achieve a saving in terms of additional components such as, for example, plugs, clamped connections or additional housings. BRIEF DESCRIPTION OF THE DRAWINGS [0031] In the figures: [0032] FIG. 1 shows a charging station with a primary transmission coil according to the prior art, [0033] FIG. 2 shows a transmission coil according to the invention in a sectional view from the side, and [0034] FIG. 3 shows a sectional illustration of a transmission coil according to the invention from above. [0035] In the following description of the figures, identical or similar components and elements are denoted by identical or similar reference symbols, wherein a repeated description of these components or elements will not be given in individual cases. The figures represent the subject matter of the invention only schematically. DETAILED DESCRIPTION [0036] FIG. 1 shows a charging station with a transmission coil according to the prior art in a schematic illustration in a cross section from the side. [0037] FIG. 1 illustrates a transmission coil 10 ′ which comprises a coil arrangement 11 ′ with a multiplicity of turns 12 ′. A ferrite element 14 ′, which serves as a ferromagnetic core of the coil arrangement 11 ′, is arranged around the turns 12 ′. The coil arrangement 11 ′ is provided with an electrically conductive shield (e.g. aluminum) 16 ′ in order to shield the magnetic stray field. [0038] In order to generate a magnetic field, the coil arrangement 11 ′ is connected to a switching cabinet 18 ′ via a connecting line 24 ′. The switching cabinet 18 ′ comprises power electronics 20 ′ and a capacitor 22 ′. The capacitor 22 ′ is connected to the coil arrangement 11 ′ via a further connecting line 26 ′, the power electronics 20 ′ and the connecting line 24 ′, wherein the coil arrangement 11 ′ and the capacitor 22 ′ together form an oscillatory circuit. [0039] If the transmission coil 10 ′ is embodied as a primary transmission coil, the oscillatory circuit is excited by means of the power electronics 20 ′, with the result that an alternating magnetic field is produced. This alternating magnetic field can be converted again into electrical current by a correspondingly equipped secondary transmission coil. If the transmission coil 10 ′ from FIG. 1 is embodied as a secondary transmission coil, the transmission coil 10 ′ is moved into the vicinity of a primary transmission coil, with the result that the alternating magnetic field of the primary transmission coil flows through the secondary transmission coil. Owing to induction in the secondary transmission coil, the oscillatory circuit is excited and the electrical energy can be extracted by means of correspondingly configured power electronics 20 ′, comprising a rectifier in this case. The electrical energy can then be used, for example, to charge an electrical energy store such as, for example, a battery or an accumulator. The electrical energy store can be assigned, in particular, to an electric vehicle or a hybrid vehicle. [0040] FIG. 2 illustrates a transmission coil 10 according to the invention in a sectional illustration from the side. [0041] The transmission coil 10 comprises a carrier 17 , which is fabricated, for example, from aluminum. A coil arrangement 11 , which comprises a multiplicity of turns 12 and a ferrite core 14 , is accommodated in the carrier 17 . The turns 12 of the coil arrangement 11 are wound around a central region 13 in a helical shape. In the central region 13 , the carrier 17 forms a trough in which integrated electronics 21 are arranged. The integrated electronics 21 comprise further, preferably all of the further, components which are necessary for operating the transmission coil 10 , in particular, for example, the power electronics and the resonant capacitance as described below with reference to FIG. 3 . The capacitance is divided here into a large number of individual capacitors which are each assigned to an individual turn 12 or a group of turns 12 . In this context, in each case a capacitor forms, together with a turn 12 or a group of turns 12 , an oscillatory circuit. [0042] FIG. 3 shows the transmission coil 10 according to the invention in a schematic view from above. [0043] FIG. 3 illustrates in transparent form the carrier 17 and the ferrite core 14 , so that the interior of the transmission coil 10 can be seen. As can be inferred from the illustration in FIG. 3 , the transmission coil 10 has a coil arrangement 11 which comprises a multiplicity of turns 12 . The illustration in FIG. 3 contains seven turns which are denoted by the reference numbers 101 , 102 , 103 , 104 , 105 , 106 and 107 . Each of the turns 12 is assigned here at least one capacitor 22 as a capacitance, wherein the capacitors are denoted by the reference numbers 121 , 122 , 123 , 124 , 125 , 126 and 127 . In each case a capacitor 22 is connected in series here with a turn 12 , with the result that an oscillatory circuit is formed. In this context, the first capacitor 121 is connected to the first turn 101 . In addition, the individual oscillatory circuits are connected one behind the other in series, with the result that the end of the first turn 101 which is not connected to the first capacitor 121 is connected to the second capacitor 122 . In this way, each turn 12 adjoins two capacitors 22 , wherein for this purpose an eighth capacitor 128 is additionally arranged at the end of the last and seventh turn. The connection to power electronics 20 is produced via the first capacitor 121 and the eighth capacitor 128 . [0044] The coil arrangement 11 can be excited by means of the power electronics 20 if the transmission coil 10 is embodied as a primary transmission coil, and an alternating magnetic field is therefore generated. Additional external components are unnecessary, and a connection to the electrical power supply system must merely be established via an electrical terminal 32 . [0045] If the transmission coil 10 is embodied as a secondary transmission coil and if it is introduced into the alternating magnetic field of a primary transmission coil, the coil arrangement 11 is excited by means of magnetic induction and an electric current can be extracted by means of the power electronics 20 . Said electric current can be made available via the electrical terminal 32 , in order, for example, to re-charge a mobile energy store. [0046] Both the power electronics 20 and the capacitors 22 can heat up during operation. In order to conduct away the heat, they are arranged on the carrier 17 , which also serves as a heat sink. If pure air cooling is not sufficient, it is possible, as outlined in FIG. 3 , to provide ducts 30 via which a cooling medium such as, for example, a water-glycol mixture can be fed in. The excess heat can be carried away by means of the cooling medium. [0047] In a further embodiment (not illustrated), each individual turn 12 is not assigned a capacitor 22 but rather a plurality of turns 12 , for example between two and ten turns 12 , are combined to form a group of turns 12 , wherein the entire group of turns 12 is assigned a capacitor 22 . [0048] In a further embodiment variant which is not illustrated in the figures, the oscillatory circuits, which are each formed from a turn 12 or a group of turns 12 and a capacitor 22 , are not connected in series with one another but rather each connected directly to the power electronics 20 . In such an embodiment, the power electronics 20 can actuate the individual turns 12 or individual groups of turns 12 separately. In this context, for example a single turn 12 or a group of turns 12 can be deactivated completely, or it would also be conceivable to excite the individual turns 12 or the oscillatory circuits, formed thereby, with different intensities. In this way, the alternating magnetic field which is generated by the coil arrangement 11 can be influenced selectively. This can be utilized to optimize the efficiency of the transmission of energy, in particular when the primary and secondary transmission coils which are used for transmitting energy are not embodied in an identical way or are not aligned with one another in an optimum way. [0049] In further variants of the transmission coil 10 it is possible to accommodate more than one coil arrangement 11 on a carrier 17 . In particular, two coil arrangements 11 can be arranged together on a carrier 17 . In this context it is possible to connect the coil arrangements 11 in such a way that the turns 12 of the respective coil arrangements 11 are connected in the same direction as one another or in opposite directions. [0050] The invention is not restricted to the exemplary embodiments described here or to the aspects emphasized herein. Instead, a multiplicity of modifications within the scope of the average ability of a person skilled in the art are possible within the range indicated by the claims.

The invention relates to a transmission coil ( 10 ) configured for inductive energy transfer, comprising a carrier ( 17 ), a coil arrangement ( 11 ) having a plurality of turns ( 12 ), and a capacitance. It is thereby provided that the capacitance is formed of a plurality of capacitors ( 22 ), wherein each capacitor ( 22 ) is assigned to an individual turn ( 12 ) or to a group of at least two turns ( 12 ) of the coil arrangement ( 11 ), and together with the coil arrangement, the capacitors ( 22 ) are arranged on the carrier ( 17 ). The invention further relates to a stationary charging station and to a vehicle, each comprising such a transmission coil ( 10 ), and to a system for the inductive charging of vehicles. No drawing text to be translated