Abstract:
An architecture for convergence systems is disclosed. The architecture includes a hardware component providing a convergence environment. A channel map services component includes a listing of receivers of programming associated with the convergence environment and a listing of channels associated with the receivers. A content services component includes a listing of programming events associated with the channels of the receivers. The content services component also includes a listing of the times of programming events. A TV services component uses the channel map services component, and the content services component to control the hardware component of the convergence environment to manage the hardware component of the convergence environment. The TV services component controls the audio/video multiplexer to reroute programing signals from receivers to outputs of the audio/video multiplexer and various devices attached to the outputs, at various times. When a conflict resolution requires time-shifting of one of the programming events, the TV services component may inform the user and seek input regarding the time-shift solution. Conflicts are resolved with minimal user intervention.

Description:
RELATED APPLICATIONS 
     This application is related to the co-assigned and co-filed applications, 
     Ser. No. 09/002,593, filed Jan. 5, 1998, “Method and system for associating web sites to television programs;” 
     Ser. No. 09/002,762, filed Jan. 5, 1998 (U.S. Pat. No. 6,003,041, issued Dec. 14, 1999), “Method for managing multiple channel maps from multiple input devices in a multimedia system;” 
     Ser. No. 09/002,990, filed Jan. 5, 1998, “Individualized parameter control for multiple media sources in a data processing system;” 
     Ser. No. 09/002,972, filed Jan. 5, 1998, “System for combining electronic program guide data;” 
     Ser. No. 09/002,584, filed Jan. 5, 1998, “System for scheduled caching of in-band data services;” 
     Ser. No. 09/002,944, filed Jan. 5, 1998, “Integration of internet sources into an electronic program database list;” 
     Ser. No. 09/002,586, filed Jan. 5, 1998 (abandoned), “Previous, favorite, and frequent channel management system[,];” 
     Ser. No. 09/002,761, filed Jan. 5, 1998, “System, apparatus and method for tuning a television to a selected channel;” 
     Ser. No. 09/002,596, filed Jan. 5, 1998, “System for resolving channel selection in a multi-channel convergence system;” and 
     Ser. No. 09/002,906, filed Jan. 5, 1998, “A system for managing favorite channels.”. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to convergence systems and more particularly to a system and an architecture for channel selection and time-shifting events in a convergent system. 
     BACKGROUND OF THE INVENTION 
     A convergence system refers to a system that includes capabilities that otherwise are provided by separate systems. For example, the Gateway Destination PC/TV system, available from Gateway 2000, Inc., provides for both computer and television capability. Rather than forcing users to have both a separate television and a separate computer, convergence systems such as the Destination PC/TV system permit users to utilize both television and computer capability within the same system. 
     Convergence systems are believed by many in the industry to represent the future of consumer electronics. Rather than having a computer in a den, and other, separate devices scattered in other rooms throughout their homes, consumers may opt for a convergence system integrating the functionality of both the computer and these separate devices. For example, convergence systems such as the Destination PC/TV system permit consumers to combine computer capability with the capability of such varying devices as digital video disc (DVD) players, direct broadcast satellite (DBS) receivers, TV tuners (for broadcast and/or cable TV), CD-ROM players, audio/video tuners having at least radio tuning capability, cable decoders, video cassette recorders, laser and compact disc players, video cameras, etc. 
     Currently, a user may have a number of TV programming sources, such as antennas, satellite receivers, cable, modem, etc., attached to the inputs of an audio/video tuner. Also attached to the outputs of the audio/video tuner are a number of devices, such as one or more displays and VCRs. Currently, in order to watch one TV program and record another, the user must remember what TV programming sources are attached to which of the output devices through the audio/video tuner. The audio/video tuner includes a multiplexer, however, the multiplexers do not manage the resources attached to the audio/video tuner. The user must manage the resources. The user must remember which devices are attached to the various inputs and outputs, and what channels or programming inputs are available on the different programming sources. The user must keep this in mind when resolving conflicts. For example, if the user wants to view a football game and record a tennis match, the user must find a programming source or input for the football game, a programming source or input for the tennis match and then must select which source to watch and which source to input to a VCR for recording. The user must also resolve conflicts in the programming. For example, the user may prefer to watch the football game from cable since the source is generally more clear than broadcast television from an antennae. If both the football game and the tennis match are both available on cable and on broadcast TV, the user must decide whether to watch the football game from the cable source or from the antennae (broadcast TV source). Sometimes users can resolve conflicts in resources by recording delayed broadcasts or rebroadcasts of a program. Users must find the rebroadcast or delayed broadcast and program an available VCR to record the later occurring program. Such a system requires users to find the alternate programs, assure that there are no other conflicts, and set the device output to record at a later time. Users are prone to making mistakes and may record the wrong program. 
     There is a need for a system for resolving conflicts that emerge when using convergence systems, such as the Destination PC/TV system. There is a need for a system that considers time-shifting as a possible solution and which can shift a start and stop time to a different receiver input. There is also a need for a system that uses the PC to record preferences and manage the resources (the input and output connections and the devices) autonomously. This makes the convergence systems much more user friendly and truly useful for the users. In addition, the human intervention is eliminated and this cuts down on the mistakes that many users may make when recording programming. 
     SUMMARY OF THE INVENTION 
     The above-identified shortcomings as well as other problems are addressed by the present invention, which will be understood by reading and studying the following specification. The invention describes a system for selecting channels in a multi-channel convergence system. The system resolves channel conflicts that emerge when using a convergence systems, such as the Destination PC/TV system. The system that uses several databases in a PC to record preferences and manage the resources (the input and output connections and the devices) autonomously with a minimal amount of intervention from the user. 
     The architecture includes a hardware component providing a convergence environment. A channel map services component includes a listing of receivers of programming associated with the convergence environment and a listing of channels associated with the receivers. A content services component includes a listing of programming associated with the channels of the receivers. A TV services component uses the channel map services component, and the content services component to control the hardware component of the convergence environment to manage the hardware component of the convergence environment. The TV services component controls the audio/video multiplexer to reroute programming signals to from receivers to outputs, audio/video multiplexer and various devices attached to the outputs. Conflicts are resolved with minimal user intervention. The TV services component manages the resources autonomously and provides a user friendly convergence environment. 
     Conflicts can also be resolved by time-shifting the use of an output device to a time when a desired program or event is available. The content services component is searched by the TV services component to locate an alternative source of programming. The TV services component also assures that the input source of programming is available at the delayed-time. If available, the user is informed of the conflict and the potential solution which requires time-shifting to another time. If the user indicates that a time-shifting solution is appropriate, the TV services stores the new start time, the source of programming, the specific channel associated with the source where the selected program or event will occur, and the output to which the device is attached. A universal program identifier can be substituted for the start and stop times. With a universal program or event identifier, the start of the actual program or event will begin the input of the program signal to a designated input and to a designated output where a device is attached. 
     In different embodiments of the invention, computers, computerized systems, and software architecture of varying scope are described. Still other and further embodiments, aspects and advantages of the invention will become apparent by reference to the drawings and by reading the following detailed description. 
    
    
     BRIEF DESCRIPTIONS OF THE DRAWINGS 
     FIG. 1 is a diagram of a typical computer in conjunction with which embodiments of the invention may be implemented. 
     FIG. 2 is a diagram of a system architecture for the system for resolving channel selection in a multi-channel system. 
     FIG. 3 is a diagram of a typical hardware configuration and shows the TV services portion communicatively coupled to the MUX controller of an audio/video multiplexer. 
     FIG. 4 is a diagram showing a portion of the TV state database associated with the TV services. 
     FIG. 5 is a diagram of a channel map database associated with the channel map services component of the invention. 
     FIG. 6 is a diagram of a first connection through an audio/video multiplexer. 
     FIG. 7 is a diagram of a first connection and second connection through an audio/video multiplexer. 
     FIG. 8 is a diagram in which the first connection through an audio/video multiplexer has been rerouted to resolve a conflict. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the inventions may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
     Referring first to FIG. 1, a diagram of a typical computer in conjunction with which embodiments of the invention may be implemented is shown. Computer  110  is operatively coupled to monitor  112 , pointing device  114 , and keyboard  116 . The computerized system provides the hardware component and the software architecture as has been described herein and as described in related co-pending application entitled ARCHITECTURE FOR CONVERGENCE SYSTEMS, assigned to the same assignee and filed on a date even herewith. Computer  110  includes a processor (preferably, an Intel Pentium processor), random-access memory (RAM) (preferably, at least thirty-two megabytes), read-only memory (ROM), and one or more storage devices, such as a hard disk drive, a floppy disk drive (into which a floppy disk can be inserted), an optical disk drive, and a tape cartridge drive. The memory, hard drives, floppy disks, etc., are types of computer-readable media. The invention is not particularly limited to any type of computer  110 . Computer  110  preferably is a PC-compatible computer running a version of the Microsoft Windows operating system. The construction and operation of such computers are well known within the art. 
     Computer  110  includes integrated therein or coupled thereto hardware to provide for what is known in the art as a “convergence environment” such that computer  110  provides capability beyond ordinary PC operation. Such capability preferably including TV capability. For example, the Gateway Destination PC/TV system, available from Gateway 2000, Inc., provides a convergence environment across two primary modes of operation: TV viewing, and PC operation. Computer  110  desirably provides for integration with or includes audio/video (i.e., multimedia) devices, including but not limited to, a sound card, a digital video disc (DVD) player, a direct broadcast satellite (DBS) receiver, a TV tuner (for broadcast and/or cable TV), audio/video inputs for external or auxiliary devices, a CD-ROM player, an audio/video tuner having at least radio tuning capability, a cable decoder, a videocassette recorder, a laser disc player, a compact disc player, a DBS integrated receiver-decoder (IRD), and a video camera. 
     Computer  110  may also be communicatively connected to the Internet, which is not shown in FIG.  1 . Internet connectivity of computers is well known within the art. In one embodiment, the computer includes a modem and corresponding communication drivers to connect to the Internet via what is known in the art as a “dial-up connection.” In another embodiment, the computer includes an Ethernet or similar hardware card to connect to a local-area network (LAN) that itself is connected to the Internet via what is known in the art as a “direct connection” (e.g., T 1  line, etc.). 
     Monitor  112  permits the display of information, including computer, video and other information, for viewing by a user of the computer. The invention is not limited to any particular monitor  112 . Such monitors include cathode ray tube (CRT) displays, as well as flat panel displays such as liquid crystal displays (LCD&#39;s). The monitor is, however, desirably a 31″ VGA monitor. Pointing device  114  permits the control of the screen pointer provided by the graphical user interface of operating systems such as versions of Microsoft Windows. The invention is not limited to any particular pointing device  114 . Such pointing devices include mouses, touch pads, trackballs, remote controls and point sticks. Finally, keyboard  116  permits entry of textual information into computer  110 , as known within the art, and the invention is not limited to any particular type of keyboard. Desirably, keyboard  116  is a wireless keyboard. 
     FIG. 2 shows a diagram of system architecture for the system for resolving channel selection in a multi-channel system. One such architecture amenable to the invention is described in the co-pending, co-filed and co-assigned application entitled “Architecture for Convergence Systems,” which is hereby incorporated by reference. The system architecture includes three components; namely, a TV services component  201 , a channel map services component  202  and an electronic program guide (“EPG”) content services component  203 . The TV services component  201  is communicatively coupled to the channel map services component  202  and the EPG content services component  203 . Communicatively coupled to the channel map services component  202  is a channel map database  204 . The channel map database  204  includes a listing of the receivers of programming signals available to the convergence system, the channels available on those receivers and the call letters of the source of the channels. The channel map database  204  will be discussed in more detail with respect to FIG.  5 . Communicatively coupled to EPG component  203  is an EPG database  205 . The EPG database  205  is a listing of programs or events and channels. The EPG database  205  is retrieved from either an in-band program guides (such as StarSight, DirecTV DSS and Echostar DBS) or out-of-band program guides (such as Electronic TV Host and Intel SmartTV) accessed through a modem  206 . Most electronic program guides use only a single source for their program guide data. StarSight uses the vertical blanking interval to access program guide data. DSS and Echostar use the system information in the MPEG II digital satellite stream to access the program guide data. TV Host and Intel SmartTV use a dial-up and file download to access the electronic program guide data. The TV services component  201  selects the various input devices and tunes the channels on these input devices or receivers. These input devices or receivers may be internal or external to the convergence system and may include an RF receiver  208 , a satellite receiver  209 , a digital receiver  210  and consumer electronics devices,  211 ,  212  such as VCRs, DVDs, etc. The TV services component  201  may control these receivers with an infrared transmitter link or some other network interface such as defined by IEEE standard number 1394. A TV state database  213  is also communicatively coupled with the TV services component  201 . 
     Now turning to FIG. 3, it can be seen that the TV services component  201  controls the convergence system audio/video multiplexer  329  through a multiplexer controller  332 . The system audio/video multiplexer  329  is a switch which controls the switching between various inputs and various outputs within the convergence system. As shown in FIG. 3, there are video inputs vi 0  denoted by reference numeral  318 , video input vi 1  denoted by reference numeral  319 , video input vi 2  denoted by reference numeral  320 , and video input vi 3  denoted by reference numeral  321 . The various video inputs  318 ,  319 ,  320  and  321  are connected to various receivers of programming signals or sources of programming, such as antenna, VCR and DBS as shown in FIG.  3 . It should be noted that the various video inputs  318 ,  319 ,  320  and  321  can be associated with any of the receivers or sources of programming shown. In other words, a particular video input does not necessarily have to be associated with the source of programming or the receiver shown in FIG.  3 . Each video input  318 ,  319 ,  320  and  321  can be attached to any of the receivers shown. 
     The system audio/video multiplexer  329  also has various outputs. As shown in FIG. 3, there is an output video out or vo 0 , denoted by the reference numeral  325 , which is a TV output for a display monitor  322 . There is also a video output vo 1  denoted by reference numeral  326  , a video output vo 2  denoted by reference numeral  328 , and a video output vo 3  denoted by reference numeral  327 . The various inputs and outputs may be internal or may be accessed through a jack on the convergence system. Attached or communicatively coupled to video output vo 1  is a VCR  323  and attached to video output vo 3  is a second VCR  324 . It should be noted that vo 2  is not used. In other words, there may not be a consumer electronics device or display attached to that particular output. Further, it should be noted that other types of consumer electronic devices or displays may be attached to any of the outputs  325 ,  326 ,  327  or  328 . 
     The TV state database  213  includes entries or information regarding the connections between the video inputs  318 ,  319 ,  320  and  321  and the video outputs  325 ,  326 ,  327  and  328 . As shown in FIG. 3, video input  318  or vi 0  is attached or electrically connected to video output  325 , also known as vo 0 . The connection path between vi 0  and vo 0  is denoted by reference numeral  330 . Similarly, video input (vi 3 )  321  is connected to video output (vo 1 )  326  via a connection path  331 . These connections are shown as being part of the TV state database  213  by an entry  335  and an entry  336 . Entry  335  corresponds to the connection path  330  through the system audio/video multiplexer  329 . The entry  335  indicates that vi 0  is the video input and that the video output for that connection is vo 0 . The entry  335  also indicates the start time and the end time for the connection path  330  through the system audio/video multiplexer  329 . The start time and end time may also have date designators within the specific entry. It there is no specific end time, the end time can be designated by a time that does not exist, such as 9999. Entry  336  in the TV state database  213  indicates that the video input vi 3  is connected to the video output vo 1 . This corresponds to the connection path  331  through the system audio/video multiplexer  329 . The entry  336  also indicates the start time and the end time for the connection path  331  through the system audio/video multiplexer  329 . The start time and end time may also have date designators within the specific entry. Of course, when additional connections are made through the system audio/video multiplexer  329 , there are additional entries made in the TV state database  213  which indicate a connection between a particular video input and a particular video output. The TV state database tracks these connections. 
     FIG. 4 is a diagram showing another portion  400  of the TV state database  213  associated with the TV services component  201 . The portion  400  of the TV state database  213  maps the hardware configuration of the convergence system&#39;s inputs and outputs. In the configuration shown in FIG. 4, a box represents the various sources of programming events. The sources can be cable, over-the-air broadcasts from one or more local antennas or from a satellite dish, or from any other source. Various devices, including programming or event signal tuner receivers and displays are attached to the system audio/video multiplexer  329 . In the example shown in FIG. 4, a display monitor  437 , a tuner  438 , a first VCR and its tuner  439 , a digital satellite set-top box  440 , and a second VCR and its tuner  441  are attached to the system audio/video multiplexer  329 . The portion  400  of the TV state database  213  provides entries  445 ,  446 ,  447 , and  448  that map the configuration shown. Each device is given a device ID  460 . The inputs from each device are provided with an input ID  462  and the outputs from each device are provided with an output ID  464 . However, some devices do not have inputs and some do not have outputs. 
     For example, the monitor  437 , designated by the entry  445 , does not include an input ID  462  since the display monitor has no input. That is to say, the audio/video multiplexer  329  only outputs a signal to the display monitor  437 . Further entry  448  relates the inputs and outputs of the digital satellite set-top-box  440 . The digital satellite set-top-box  440  is not an output device since it only inputs a signal or signals to the audio/video multiplexer  329 . Consequently, entry  448  has no output ID  464 . The internal TV tuner  438 , the first VCR  439  and the second VCR  441  are all attached to the source. The VCRs,  439  and  441 , each have an internal tuner as well. Each of these devices has an input ID  462  and an output ID  464 . Consequently, each of the entries  446  (related to the internal TV tuner  438 ),  447  (related to the first VCR  439 ), and  450  (related to the second VCR  441 ) has an input and an output with a unique identifier. 
     FIG. 5 illustrates various entries within the channel map database  204  associated with the channel map services  202 . The channel map database  204  includes entries for each device or receiver associated with the convergence system. Each device or receiver has a number of channels associated with that device. The sum total of channels available on the various devices are given a logical channel number  510 . Associated with each logical channel number  510  is a device or receiver ID  512 , the physical channel  514  associated with the particular device or receiver  512 , and the channel name  516 . The channel name is the source of television programming. For example, the channel name might be one of the major networks, such as ABC, CBS, NBC or Fox, or any of the other programming sources such as TNT, WNBC, MTV, and any other source of programming that might be available. In FIG. 5, the entries are listed for four devices or receivers, denoted by device IDs  512 , D 1 , D 2 , D 3  and D 4 . The devices can be any type of receiver of programming signals. As shown in FIG. 5, there are a plurality of entries  550 - 558  in the channel map database  204  comprising  358  logical channels. The logical channel number  510  for each of the entries is unique to the particular entry. For example, on entry  550 , the logical channel number  510  is  1 ; for the entry  551 , the logical channel number  510  is  2 ; for entry  555 , the logical channel number  510  is  6 ; and for entry  556 , the logical channel number  510  is  356 , etc. The final entry  358  has a logical channel number  358 . The three dots between entries  555  and  556  include the entries for logical channel number  7  through logical channel number  355 . It should be noted that there are duplicate channels available for the same source of programming. For example, entry  551  and entry  552  both have the physical channel  514  as channel number  4  and the channel name  516  or source of programming is Fox. In real terms, this means that channel  4  on the Fox network is available on device or receiver D 2  as well as device or receiver D 4 . Therefore, Fox channel  4  is available on both the devices D 2  and D 4 . Even so, each one is given a different logical channel number to uniquely identify that particular channel. Thus, within the database, there are duplicates of a particular physical channel on a particular network or source of programming. It should also be noted, such as at entry  557 , that logical channel number  357  carries a West Coast version of physical channel  222  from NBC. In other words, the channel  222  is a delayed broadcast of a previously broadcast East Coast version. 
     Now turning to FIGS. 6,  7  and  8 , the operation of the system will be discussed. When the user attempts to change channels or select devices or receivers that conflict with the representation of the system audio/video multiplexer  329 , the TV services component  201  attempts to find a connection path that obeys the interruption setting stored in the TV state database  213 . As shown in FIG. 6, the user is watching an off-air television program from an antenna receiver which passes through video input vi 0   318 , and connected to video output vo 0   325 . The video output  325  is attached to the display monitor  322 . The connection  330  is the same as that shown in FIG.  3  and which is shown as entry  335  in the TV state database  213 . 
     Now turning to FIG. 7, the user selects to record the current program that the user is watching and, therefore, a new connection path  710  is formed where video input vi 0 ,  318 , is connected to video output vo 1   326  and in turn to VCR 1 ,  323 . Up until this point, there is no conflict since each of the connections can be accommodated. 
     Now turning to FIG. 8, if the user selects a program or event that is available on video input vi 0  and which is not the current program also being recorded, a conflict arises. The audio/video multiplexer cannot re-tune the video input vi 0 ,  318  without affecting the recording of the current program to video output or vo 1   326 . The TV services component  201  determines that there is a conflict condition and then searches the content services component  203  and specifically the EPG database  205  for an alternative source of programming signals from another programming receiver. When an alternative source of programming and a connection is available between the associated video input and the video output, a new connection is formed in the system audio/video multiplexer  329 . In the example shown in FIG. 8, the selected program that the user wants to display on the monitor  322  would be available on the receiver connected to vi 2 ,  321  a new connection  810  is formed between vi 2 ,  320  and vo 0 ,  325 , and once the new connection  810  is made, the TV state database  213  is updated with an entry that includes a video input of vi 2  and a video output of vo 0 . After updating the connections in the TV state database, the TV services component  201  awaits the next potential conflict. 
     In some instances, it is impossible to come up with a conflict resolution that provides a currently available connection through the system audio/video multiplexer  329 . In this instance, the television services component searches the content services component  203  and specifically the EPG database  205  for a selected program that is being re-broadcast or is available at an alternative start time, which is beyond the time needed to watch or record the current event. The TV services component  201  checks the channel map services component  202 , and specifically the channel map database  204 , to determine if one of the receivers of programs will receive the event at the later time found in the electronic program guide database  205 . If the later event is available on one of the receivers, after checking the EPG database  205  and the channel map database  204 , the TV services component  201  notifies the user of the conflict and identifies an alternate start time for either the event to record or the event in conflict. In one embodiment, the user is asked to resolve the conflict. In another embodiment, a default condition or user preference can be stored within the system. The default or condition is a rule applied by the system for resolving the conflict. The default or conflict condition may be selected by the system automatically or after a desired delay where the user is given a chance to select but has not acted. After the user identifies which alternative is desirable, the TV services component  201  makes a connection between the appropriate video input and the appropriate video output through the system audio/video multiplexer  329  and also records it at the later time. The second option for recording or viewing at the delayed time is also recorded. At the later time, the TV services component  201  implements the desired connection to produce the time-delayed broadcast or recording. Many times, a delayed broadcast for another time zone will provide the desired solution. 
     The TV services component  201  initially determines the presence of a conflict condition at a first time where there are multiple requests for a first programming signal and a second programming signal from a first programming receiver. The conflicts can not be resolved in real time by changing connection paths through the audio/video multiplexer  329 . The TV services component then searches for an alternative source of programming signals from a second programming receiver. Once an alternative source of programming signals is found, the TV state database  213  is searched to determine if the connection is available at the delayed time (delayed start time to the delayed stop time). The entries  335  and  336  (shown in FIG. 3, are checked for the start and stop times). Similarly, the entries  445 ,  446 ,  447 , and  448  are searched to determine if there are time conflicts with a specific device. If no conflicts are found, the later source of programming is listed as an option. Of course, there may be many sources of the same programming event. Each programming event is checked in a similar manner and the available options are listed for the user&#39;s selection. The user is given notice that the current request can not be accommodated and is also presented with a list of options, one of which may be selected. If the user selects an option, the selected option is recorded in memory. The TV services component  201  then implements the solution at the selected time and makes the connection through the audio/video multiplexer  329  at the appointed time. This resolves the conflict. 
     In one embodiment it may be advantageous to store all the unselected options in the case where another current conflict has solutions which conflict with other time-shifted solutions. In another embodiment, the above process is repeated since there may be event changes in the content services component  203  of the convergence system. In still another embodiment, the EPG database  205  of the content services component  203  is searched periodically to assure that there have been no changes in the times of the events from those recorded in memory as time-shifted solutions for conflicts. 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the following claims and equivalents thereof.