METHOD AND APPARATUS FOR DISCRIMINATING, AUTHENTICATING AND/OR COUNTING DOCUMENTS

Abstract: A currency counting and discrimination device (10) for receiving a stack of currency bills, rapidly counting and discriminating the bills in the stack (20), and then re-stacking the bills. The device comprises an input receptacle (209) for receiving a stack of currency bills to be discriminated, a discriminating unit (30) for discriminating the denomination of the currency bills, and one or more output receptacles (217) for receiving the currency bills after being discriminated by the discriminating unit (30). The device further comprises a transport mechanism (16) for transporting the currency bills, one at a time, from the input receptacle (209) past a sensor of the discriminating unit and to the one or more output receptacles (217). One or more counters keep track of the value of bills that are discriminated.

Description: METHOD AND APPARATUS FOR DISCRIMINATING, AUTHENTICATING AND/OR COUNΗNG DOCUMENTS Field of the Invention The present invention relates, in general, to document identification. More specifically, the present invention relates to an apparatus and method for discriminating among a plurality of document types such as currency bills of different denominations, authenticating the genuineness of the same, and/or sorting die same. According to one embodiment the present invention also relates to a mechanism and method for detecting and clearing a jam from a machine which discriminates and counts currency bills. Background of the Invention In some currency discriminators bills are transported, one at a time, passed a discriminating unit. As the bills pass the discriminating unit, the denomination of each bill is determined and a running total of each particular currency denomination and/or of the total value of the bills that are processed is maintained. A number of discriminating techniques may be employed by the discriminating unit including optical or magnetic scanning of bills. A plurality of output bins are provided and the discriminator includes means for sorting bills into the plurality of bins. For example, a discriminator may be designed to recognize a number of different denominations of U.S. bills and comprise an equal number of output bins, one associated with each denomination. These discriminators also include a reject bin for receiving all bills which cannot be identified by the discriminating unit. These bills may later be examined by an operator and then either re-fed through the discriminator or set aside as unacceptable. Depending on the design of a discriminator, bills may be transported and scanned either along their long dimension or their narrow dimension. For a discriminator that transport bills in their narrow dimension, it is possible that a given bill may be oriented either face up or face down and either top edge first ("forward" direction) or top edge last ("reverse" direction). For discriminators that transport bills in their long dimension, it is possible that a given bill may be oriented either face up or face down and either left edge first ("forward" direction) or left edge last ("reverse" direction). The manner in which a bill must be oriented as it passes a discriminating unit depends on the characteristics of the discriminator. Some discriminators are capable of identifying the denomination of a bill only if it is fed with a precise orientation, e.g., face up and top edge first. Other discriminators are capable of identifying bills provided they are "faced" (i.e., fed with a predetermined face orientation, that is all face up or all face down). For example, such a discriminator may be able to identify a bill fed face up regardless of whether the top edge is fed first or last. Other discriminators are capable of identifying the denomination fed with any orientation. However, whether a given discriminator can discriminate between bills fed with different orientations depends on the discriminating method used. For example, a discriminator that discriminates bills based on patterns of transmitted light may be able to identify the denomination of a forward fed bill regardless of whether the bill is fed face up or face down, but the same discriminator would not be able to discriminate between a bill fed face up and a bill fed face down. There remains a need for a discriminator that can detect and flag the presence of a bill oriented with an incorrect forward/reverse orientation and a discriminator that can sort between forward-oriented bills and reverse-oriented bills. Furthermore, for a number of reasons, a discriminating unit may be unable to determine the denomination of a bill. These reasons include a bill being excessively soiled, worn, or faded, a bill being torn or folded, a bill being oriented in a manner that the discriminating unit cannot handle, and the discriminating unit having poor discriminating performance. Furthermore, the discriminating unit and/or a separate authenticating unit may determine mat a bill is not genuine. In current discriminators, such unidentified or non-genuine bills are deposited in a reject receptacle. A characteristic of the above described discriminators is that the value of any rejected unidentified bills is not added to the running total of the aggregate value of the stack of bills nor do the counters keeping track of the number of each currency denomination reflect the rejected unidentified bills. While this is desirable with respect to bills which are positively identified as being fake, it may be undesirable with respect to bills which were not identified for other reasons even though they are genuine bills. While the bills in a reject receptacle may be re-fed through the discriminator, the operator must then add the totals from the first batch and the second batch together. Such a procedure can be inefficient in some situations. Also, if a bill was rejected the first time because it was, for example, excessively soiled or too worn, then it is likely that the bill will remain unidentified by the discriminating unit even if re-fed. A problem with the above described situations where the totals and/or counts do not reflect all the genuine bills in a stack is that an operator must then count all the unidentified genuine bills by hand and add such bills to separately generated totals. As a result the chance for human error increases and operating efficiency decreases. Take for example a bank setting where a customer hands a teller a stack of currency to be deposited. The teller places the stack of bills in a discriminator, the display on the discriminator indicates that a total of $730 has been identified. However, fourteen genuine bills remain unidentified. As a result, the teller must count these fourteen bills by hand or re-fed through the discriminator and then add their total to the $730 total. An error could result from the teller miscounting the unidentified bills, the teller forgetting to add the two totals together, or the teller overlooking the unidentified bills entirely and only recording a deposit of $730. Moreover, even if die teller makes no mistakes, me efficiency of the teller is reduced by having to manually calculate additional totals. The decrease in efficiency is further aggravated where detailed records must be maintained about the specific number of each denomination processed during each transaction. Therefore, there is a need for a currency discriminator which is capable of conveniently and efficiently accommodating genuine bills that, for whatever reason, remain unidentified after passing through the discriminating unit of a discriminator. There is also a need for a currency discriminator that makes it easy for an operator to reconcile the value of any flagged bills so that ti eir value will be reflected in appropriate counters keeping track of processed bills. Additionally, there is a need for a discriminator that will prompt the operator as to the denominations of any flagged bills. Additionally, in processing stacks of documents such as currency bills, it is often desirable to sort out specific types of documents such as currency bills having a specific denomination. For a currency scanning and discriminating machine to operate, currency bills are conveyed by a transport mechanism along a transport path from an input receptacle, past a sensing device, and to an output receptacle. In normal operation, a controller monitors the signals received from the sensing device and determines the denomination of each currency bill mat is scanned. However, a bill or bills can become jammed in the transport path, especially near the sensing device. Any jamming results in the machine being nonoperational. Thus, it is desirable to detect and clear the jammed currency bills in a simplistic and timely manner. Summary Of The Invention It is an object of the present invention to provide an improved method and apparatus for identifying, audienticating, and/or counting currency bills comprising a plurality of currency denominations. It is an object of the present invention to provide an improved currency scanning and counting machine which is relatively simple and compact, while at the same time providing a variety of advanced features which make the machine convenient and useful to the operator. It is a further object of diis invention to provide such a machine that is capable of operating at a faster throughput rate than any previous machine able to determine the denomination of the scanned bills. It is another object of this invention to provide an improved document counting and discriminating apparatus that is capable of flagging unidentified bills or bills meeting or failing to meet certain criteria. Bills may be flagged, for example, by routing flagged bills to a special location and/or suspending operation of the apparatus. It is another object of this invention to provide an improved document counting and discriminating apparatus of the above type that can conveniently be caused to resume operation after an operator of the apparatus has examined an unidentified bill. It is another object of this invention to provide an improved document counting and discriminating apparatus of the above type whereby the denomination or kind of any unidentified bill may be conveniently added to appropriate counters and the operation of the apparatus conveniently resumed when an operator determines that an unidentified bill is acceptable and whereby the operation of the apparatus may be conveniently resumed without adversely affecting any counter when an operator determines that an unidentified bill is not acceptable. It is another object of this invention to provide an improved document counting and discriminating apparatus whereby the discriminator prompts the operator as to the identity of any flagged bills, such as by prompting the operator as to the denomination of any bill whose denomination has not been determined by the discriminator. It is another object of this invention to provide an improved document discriminating apparatus mat can flag and/or sort documents based on the forward or reverse orientation, i.e., top edge first or top edge last, of the document. It is another object of this invention to provide a document discriminating apparatus that can detect and clear jammed currency bills in a simplistic and timely manner. It is another object of the present invention to provide an improved method and apparatus for authenticating documents which improves die ability of a system to accurately reject improper documents while reducing the likelihood of rejecting genuine documents. In accordance with one embodiment of the present invention, die foregoing objectives are realized by providing a currency counting and discrimination device for receiving a stack of currency bills, rapidly counting and discriminating d e bills in ie stack, and dien re-stacking the bills. This device includes an input receptacle for receiving a stack of currency bills to be discriminated, a discriminating unit for discriminating the currency bills by denomination, one or more output receptacles for receiving the currency bills after they have been discriminated, and a transport mechanism for transporting die currency bills, one at a time, from the input receptacle past die discriminating unit and to one or more output receptacles. In one embodiment of die present invention, scanheads are positioned on bodi sides of a document transport path so as to permit scanning of eid er or both sides of a document. According to one embodiment, each bill is scanned by die discriminating unit and generated scanned patterns are compared to and correlated against stored master patterns associated widi genuine bills of one or more denominations. According to one embodiment, two or four characteristic patterns are generated and stored widiin system memory for each detectable bill-type. The stored patterns correspond, respectively, to optical scans performed on one or bom sides of a bill along "forward" and "reverse" directions relative to the pattern printed on the bill. According to d e correlation technique of one embodiment, me pattern generated by scanning a bill under test and processing the sampled data is compared widi each of ie prestored characteristic patterns to generate, for each comparison, a correlation number representing the extent of similarity between corresponding ones of the plurality of data samples for the compared patterns. Bill identification is based on designating the scanned bill as belonging to die bill-type corresponding to d e stored characteristic pattern for which the correlation number resulting from pattern comparison is determined to be die highest. In one embodiment, the invention is particularly adapted to be implemented wim a system programmed to track each identified currency identity so as to conveniently present aggregate totals for bills diat have been identified at d e end of a scan run. According to one embodiment a currency discriminator is provided mat counts and discriminates bills as d ey pass a discriminating unit and mat flags an unidentified bill or one having a predetermined characteristic, for example a bill having a specified orientation, by transferring die flagged bill to a location where it can be convenientiy examined by an operator and d en suspending me operation of die discriminator. The operator may then examine the bill and deteπnine whed er d e bill is acceptable or not. Denomination selection elements such as keys are provided to enable d e operator widi die depression of a single button to indicate d e denomination of an unidentified but acceptable bill, to cause die value of d e bill to be reflected in any appropriate counters, and to cause d e discriminator to resume operation. A continuation selection element is also provided to enable die operator to cause the discriminator to resume operation without adversely affecting any counters when an unidentified bill is determined to be unacceptable. According to one embodiment of die present invention, a discriminator is provided wim a single output receptacle in which all bills are stacked after diey pass by die discriminating unit. When an unidentified bill is detected, die discriminator halts operation widi d e unidentified bill positioned at a predetermined location widiin the stack such as at die top or back of the stack of bills in d e output receptacle or at a predetermined position just prior to the stack. The bill may then be conveniently examined by d e operator. According to anodier embodiment of d e present invention, a discriminator is provided wid an examining station where unidentified bills are transferred before d e discriminator halts operation. Upon determination mat a bill is acceptable, d e bill may men be transferred to the output receptacle in a single output receptacle discriminator or to an output receptacle associated wid die denomination or other characteristic of die bill in a multi-output receptacle discriminator. Additionally, a reject receptacle may be provided for receiving bills which are determined to be unacceptable. In one embodiment, a discriminator is provided widi two or more output receptacles. All flagged bills are delivered to a separate output receptacle while die discriminator continues to process any remaining bills. Alternatively, bills diat are positively determined to be suspect bills may be delivered to one output receptacle, all odier flagged bills may be delivered to a second output receptacle, and all unflagged and identified bills may be delivered to one or more additional output receptacles. In another embodiment, suspect bills are routed to a separate output receptacle while all odier bills are routed to one or more additional output receptacles. The discriminator, in another embodiment is designed to suspend operation upon encountering one or more types of flagged bills. For example, the discriminator may halt operation when a no call bill is detected but not when a suspect bill is detected, e.g., when suspect bills are routed to an output receptacle separate from the output receptacle or receptacles to which odier bills are routed. According to anodier embodiment, the discriminator does not suspend its operation 8 upon detecting a flagged bill but rad er continues processing any remaining bills, e.g., when flagged bills are routed to one or more output receptacles separate from e output receptacle or receptacles to which non-flagged bills are delivered. According to one embodiment, the value of any flagged bill such as a no call is reconciled on-die-fly, that is, at d e time such bill is encountered. According to one such embodiment, d e discriminator suspends operation until me value of die flagged bill is reconciled. According to anodier embodiment, the value of any flagged bills is reconciled after all bills have been processed. Alternatively, die reconciliation process may begin before all bills have been processed but widiout suspending die processing of the remaining bills. According to one embodiment, denomination indicating means are provided to permit me operator to indicate die value of a flagged bill such as a no call. Examples of denomination indicating means include, for example, denomination selection elements such as keys, buttons, switches, lights, and displayed keys, denominations, or messages. Such elements may be selected by, for example, pressing an appropriate one of such elements or using scroll keys. The selection of a denomination may cause that denomination to be indicated to die discriminator or, alternatively, a denomination may first have to be selected and dien indicated to d e discriminator by selecting an accept, yes, or enter key. According to one embodiment, prompting means are provided whereby the discriminator is able to suggest a denomination to the operator of me discriminator in connection wid a flagged bill such a no call. Examples of criteria used in prompting a denomination to the operator in connection wid a flagged bill include suggesting a denomination or a sequence of denominations based on a default basis, random basis, user-defined basis, manufacturer defined basis, last bill information, last no call information, last called denomination information, historical information, comparison of scanned and reference information such as correlation information. Means for prompting a denomination may include, for example, displaying a message, highlighting or illuminating a denomination selection or indicating element or associated light. According to anodier embodiment of die present invention, a discriminator discriminates a stack of bills and flags bills having a given forward/reverse orientation. Accordingly, when a stack of bills predominately oriented in die forward or reverse direction is discriminated by the discriminator, any bills oriented in the opposite forward/reverse direction may be flagged. Any flagged bills may either be removed widiout replacement or re-oriented in die appropriate forward or reverse direction. As a result, a stack of bills may be generated in which all bills have d e same forward/reverse orientation. Alternatively, in a multi-output receptacle discriminator, instead of flagging bills based on dieir forward/reverse orientation, bills having a forward orientation may be routed to one output receptacle and those having a reverse orientation may be routed to anodier output receptacle. Likewise a discriminator may flag or sort bills based on dieir face orientation, diat is face up or face down, or bills not belonging to a given denomination. Furthermore, the above criteria may be combined in various operating modes of the discriminator. According to a sorting mode according to one embodiment, die operator of a document discriminator embodying a sorting mode according to d e embodiment selects a document type to be separated from the remaining document types. For example, the operator may designate $20 bills to be off-sorted from a stack of U.S. currency bills having a plurality of denominations. When a stack of currency bills is subsequently processed by die currency discriminator, me discriminator proceeds to process all bills in the stack until it encounters the first $20 bill. The discriminator then halts operation widi die first $20 bill being d e last bill deposited in d e output receptacle of die discriminator. The operator may then remove all the bills in die output receptacle and separate the $20 bill from the odier bills. The currency discriminator may restart automatically when all the bills in the output receptacle are removed or alternatively, die discriminator may be designed to require the selection of a continuation key. The discriminator then continues to process the remaining bills until it encounters the first non-$20 bill. Upon encountering die first non-$20 bill, the discriminator halts operation widi die non-$20 bill being die last bill deposited in die output receptacle. The operator may then remove all the bills in the output receptacle, separate die non-$20 bill from die preceding $20 bills, and place me bills in appropriate stacks. The discriminator dien proceeds processing d e remaining bills, now halting upon encountering die first $20 bill. The operation proceeds as above widi die discriminator toggling between halting upon detecting d e first bill not of the designated denomination and die first bill of die designated denomination. In this way, die operator may conveniently separate a designated denomination from bills having a plurality of denominations. Likewise die above operation may be repeated widi die remaining bills to sort out a different denomination, for example, $10 bills. The above sorting operation is particularly suited for sorting bills in a stack wherein like denominated bills are grouped togedier. For example, it has been noticed diat when customers make deposits at banks, d e stacks of currency diey give to die teller or odierwise deposit widi die bank, e.g., night deposit box or automatic teller machine, tend to have bills grouped togedier by denomination. The above sorting operation is particularly useful when employed wim a currency discriminator having a single output receptacle. Nonedieless, the above sorting operation may be performed on multi-output receptacle discriminators as well, e.g., in a two output pocket discriminator wherein one pocket is dedicated to a specific purpose such as collecting suspect or unrecognized documents. According to a jam detection and clearing embodiment of the present invention, a medium for detection and clearing of a jam in a currency scanning and discriminating machine is provided. The jam detection and clearing mechanism advantageously minimizes me efforts required by die machine operator and, dierefore, reduces die time required to clear the jam. Furthermore, by minimizing die efforts of die operator, die likelihood die operator will become injured is lessened as is die probability the operator will damage the sensing device adjacent die transport padi. In accordance widi die present invention, if a bill becomes jammed during normal operation, a controller widiin die machine detects die jam through at least one of several methods. The controller may monitor me time required for a currency bill to pass by two sets of optical sensors which perform different functions. Additionally, die controller may monitor the speed of the transport mechanism to detect whedier die speed is significantly less dian die normal operational speed. Once a jam is detected, me controller interrupts the driving of die transport mechanism. The invention then provides for various manual and automatic devices which relieve die pressure exerted on die jammed bill by die transport mechanism. One such device for relieving the pressure is by providing a Sensing device d at may moved away from die transport path diereby increasing die gap between the sensing device and die transport pad . The operator then can activate die transport mechanism in a reverse or forward direction to remove the jammed currency bill. The transport mechanism is d en returned to its operational position, and die currency scanning and discriminating machine is ready to be operated. According to one embodiment a document to be audienticated is illuminated widi ultraviolet light and die amount of ultraviolet light which is reflected off die document is measured. Based on die amount of ultraviolet light which is detected, d e document is either audienticated or rejected. In die case of documents being authenticated relative to United States currency, a bill is rejected if a high level of reflected ultraviolet light is not detected. In anodier embodiment, a document is illuminated widi ultraviolet light and bodi die amount of reflected ultraviolet light and die amount of emitted visible light are measured. Based on die amount of ultraviolet light detected and die amount of visible light detected, a document is eimer audienticated or rejected. In die case of documents being audienticated relative to United States currency, a bill is rejected if eidier a high level of reflected ultraviolet light is not detected or even a low level of visible light is detected. It is known diat some counterfeit United States bills fluoresce, or emit visible light, when illuminated by ultraviolet light. As genuine United States currency does not fluoresce, the emission of visible light has been employed as a means of detecting counterfeit United States currency. However, it has been found diat not all counterfeit United States bills fluoresce; and hence, such counterfeits will not be detected by die above described fluorescence test. It has been found diat genuine United States currency reflects a high level of ultraviolet light when illuminated by an ultraviolet light source. It has also been found diat some counterfeit United States bills do not reflect a high level of ultraviolet light. Such counterfeit bills may or may not also fluoresce under ultraviolet light. The present invention employs an aumentication test wherein die amount of reflected ultraviolet light is measured and a bill is rejected if it does not reflect a high amount of ultraviolet light. By employing such a test, counterfeit United States bills which do not reflect a high level of ultraviolet light may be properly rejected. While not all counterfeit United States bills fail to reflect a high level of ultraviolet light and hence not all counterfeit United States bills will be detected using diis test, die present invention provides an additional means for detecting counterfeit bills which might otherwise go undetected. Furthermore, the likelihood of a counterfeit United States bill going undetected may be further reduced by employing an alternative embodiment of the present invention wherein botii die amount of reflected ultraviolet light and die amount of emitted visible light are measured. In such a system, a bill is rejected as counterfeit if either it fails to reflect a high level of ultraviolet light or it fluoresces. The above described embodiments may be adapted to autiienticate currencies from odier countries and odier types of documents such as food stamps and checks. For instance some genuine documents may be designed to reflect ultraviolet light only in certain locations and/or in a predetermined pattern. An alternative embodiment of die present invention may be designed to accept documents which exhibit similar characteristics while rejecting those which do not. Likewise, an alternative embodiment of die present invention may be employed to autiienticate documents based on botii their characteristics with respect to reflected ultraviolet light and dieir characteristics with respect to fluorescent emissions, e.g., detecting die amount, location, and/or pattern of fluorescent emissions. According to one embodiment, die thresholds for one or more authentication tests such as ultraviolet, fluorescence, and/or magnetic tests may be adjustable between high or low sensitivity settings. Each setting may be adjusted among a plurality of settings of varying sensitivity. These tests and plurality of setting may be employed in, for example, note counters or currency discriminators. According to one embodiment, me selection of a high or low setting for one or more of the above tests may be on a global basis, that is, the same setting will apply to all processed documents. According to one embodiment, die selection of a high or low setting for one or more of the above tests may be on an individual document-type basis such as by providing for various settings based on die denomination of a currency bill. For example, the settings for the above tests may be set to lower sensitivities for bills of lower denomational value such as $ls and $2s and to higher sensitivities for bills of higher denomination value such as $20s, $50s, and $100s. Accordingly die chance of wrongly flagging genuine bills of low denominational values as suspect can be reduced while at die same time the chance of wrongly failing to detect counterfeit bills of higher denominational values can also be reduced. The above summary of the present invention is not intended to represent each embodiment, or every aspect of the present invention. This is the purpose of the figures and detailed description which follow. Brief Description Of The Drawings FIG. 1 is a perspective view of a currency scanning and counting machine embodying die present invention; FIG. 2 is a functional block diagram of the currency scanning and counting machine of FIG. 1 illustrating an embodiment in which a scanhead is arranged on each side of a transport padi; Fig. 3 is a flow chart illustrating die sequence of operations involved in determining die bill denomination from the correlation results; FIG. 4a is a flow chart illustrating the sequence of operations involved in determining me bill denomination from the correlation results using data retrieved from the green side of U.S. bills according to one embodiment of the present invention; FIGs. 4b and 4c are a flow chart illustrating the sequence of operations involved in determining me bill denomination from the correlation results using data retrieved from the black side of U.S. bills; Fig. 5 is a vertical sectional view approximately through the center of the machine of FIG. l which illustrates the transport rolls and mechanisms in a side elevation; Fig. 6 is a section view of the sensing device; FIG. 7a is a section view of the lower member of the sensing device and an end elevation of the upper member of the sensing device; FIG. 7b is a section view of die lower member of the sensing device and an end elevation of die upper member of the sensing device in which the handles are latched onto a shaft; FIG. 8 is a section view of the sensing device incorporating solenoids for separating die two members of the sensing device; FIG. 9 is an enlarged bottom plan view of me lower member of the scanning device of Fig. 6 or 8 and d e passive transport rolls mounted on die lower member; FIG. 7 is a bottom plan view of die upper member in the scanning device of Fig. 6 or 8 which includes die upper scanhead; FIG. 11 is a block diagram illustrating the components used by die jam detection and clearing mechanism; FIG. 12 is an enlarged plan view of die control panel and the display panel of the machine in FIG. 1; FIGS. 13a- 13c are flow charts illustrating the sequential procedure followed in clearing a jammed currency bill according to an embodiment of the present invention. Fig. 14 is a functional block diagram illustrating one embodiment of a document authenticator and discriminator according to the present invention; Fig. 15 is a functional block diagram illustrating anodier embodiment of a document authenticator and discriminator according to die present invention; Fig. 16a is a functional block diagram illustrating another embodiment of a document authenticator and discriminator according to die present invention; Fig. 16b is a functional block diagram illustrating another embodiment of a document authenticator and discriminator according to the present invention; Fig. 17 is an enlarged plan view of die control and display panel in die machine of FIG. 1; Fig. 18 is a flow chart illustrating the sequential procedure involved in a sorting operation according to an embodiment of the present invention. FIGs. 19-24 are enlarged plan views of various embodiments of control panels; Fig. 25 is an exploded perspective view of a touch screen device. FIG. 26a is a side view of one embodiment of a document autiienticating system according to die present invention; FIG. 26b is a top view of me embodiment of FIG. 26a along die direction 26b; FIG. 26c is a top view of die embodiment of FIG. 26a along die direction 26c; and Fig. 27 is a functional block diagram illustrating one embodiment of a document autiienticating system according to die present invention. Detailed Description Of The Embodiments While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of die invention as defined by die appended claims. Referring now to FIGs. 1 and 2, tiiere is shown one embodiment of a currency scanning and counting machine 10 according to die present invention. The machine 10 includes an input receptacle or bill accepting station or input hopper 12, 209 where stacks of currency bills that need to be identified and counted are positioned. Bills in die input receptacle are acted upon by a bill separating station 14 which functions to pick out or separate one bill at a time for being sequentially relayed by a bill transport mechanism 16 (FIG. 2), according to a precisely predetermined transport path, between a pair of sensors or scanheads 18a, 18b where die currency denomination of die bill is scanned and identified. In one embodiment, bills are scanned and identified at a rate in excess of 800 bills per minute. In die embodiment depicted, each scanhead 18a, 18b is an optical scanhead diat scans for characteristic information from a scanned bill 17 which is used to identify die denomination of the bill. The scanned bill 17 is dien transported to an output receptacle or bill stacking station 20, 217 where bills so processed are stacked for subsequent removal. As seen in FIG. 1 , the output receptacle 217 comprises stacker wheels 212, 213 which project upwardly tiirough a pair of openings in a stacker plate 214 to receive the bills as they are advanced across die downwardly sloping upper surface of die stacker plate 214. The stacker wheels 212 and 213 are supported for rotational movement about a shaft 215 journalled on die rigid frame and driven by a stacker motor 216. The operation of die currency scanning and counting machine 10 of FIGs. 1 and 2 is described in more detail in PCT application Serial No. PCT/US95/02992. See also U.S. Pat. No. 5,295,196. Such discrimination systems may process bills at speeds of die order of 800 to 1500 bills per minute, including speeds in excess of 800 and 1000 bills per minute according to various embodiments. Each optical scanhead 18a, 18b preferably comprises a pair of light sources 22 directing light onto the bill transport path so as to illuminate a substantially rectangular light strip 24 upon a currency bill 17 positioned on die transport padi adjacent die scanhead 18. Light reflected off d e illuminated strip 24 is sensed by a photodetector 26 positioned between die two light sources. The analog output of the photodetector 26 is converted into a digital signal by means of an analog-to-digital (ADC) convenor unit 28 whose output is fed as a digital input to a central processing unit (CPU) 30. While scanheads 18a, 18b of FIG. 2 are optical scanheads, it should be understood diat it may be designed to detect a variety of characteristic information from currency bills. Additionally, die scanhead may employ a variety of detection means such as magnetic, optical, electrical conductivity, and capacitive sensors. Referring again to FIG. 2, as a bill 17 traverses die scanheads 18a, 18b, die coherent light strip 24 effectively scans the bill. A series of detected reflectance signals are obtained across d e die bill and d e resulting analog signals are digitized under control of die CPU 30 to yield a fixed number of digital reflectance data samples. The normalized reflectance data represents a characteristic pattern that is unique for a given bill denomination and provides sufficient distinguishing features among characteristic patterns for different currency denominations. In order to ensure strict correspondence between reflectance samples obtained by scanning of successive bills, die reflectance sampling process is preferably controlled tiirough the CPU 30 by means of an optical encoder 32 which is linked to die bill transport mechanism 16 and precisely tracks the physical movement of the bill 17 between the scanheads 18a, 18b. More specifically, die optical encoder 32 is linked to the rotary motion of the drive motor which generates the movement imparted to die bill along die transport padi. In addition, the mechanics of the feed mechanism ensure that positive contact is maintained between d e bill and die transport padi, particularly when die bill is being scanned by die scanheads. Under these conditions, die optical encoder 32 is capable of precisely tracking the movement of the bill 17 relative to the light strips 24 generated by die scanheads 18a, 18b by monitoring the rotary motion of the drive motor. The optical sensing and correlation technique is based upon using the above process to generate a series of stored intensity signal patterns using genuine bills for each denomination of currency that is to be detected. According to one embodiment, two or four sets of master intensity signal samples are generated and stored within the system memory, preferably in the form of an EPROM 34 (see FIG. 2), for each detectable currency denomination. According to one embodiment tiiese are sets of master green-surface intensity signal samples. In the case of U.S. currency, the sets of master intensity signal samples for each bill are generated from optical scans, performed on die green surface of die bill and taken along botii the "forward" and "reverse" directions relative to the pattern printed on die bill. Alternatively, the optical scanning may be performed on die black side of U.S. currency bills or on either surface of foreign bills. Additionally, die optical scanning may be performed on both sides of a bill. The CPU 30 is programmed to identify die denomination of die scanned bill as corresponding to die set of stored intensity signal samples for which the correlation number resulting from pattern comparison is found to be the highest. If a "positive" call can not be made for a scanned bill, an error signal is generated. Using the above sensing and correlation approach, the CPU 30 is programmed to count die number of bills belonging to a particular currency denomination as part of a given set of bills diat have been scanned for a given scan batch, and to determine the aggregate total of the currency amount represented by the bills scanned during a scan batch. The CPU 30 is also linked to an output unit 36 (FIG. 2) which is adapted to provide a display of die number of bills counted, die breakdown of die bills in terms of currency denomination, and die aggregate total of die currency value represented by counted bills. The output unit 36 can also be adapted to provide a print-out of the displayed information in a desired format. A correlation formula which may be used in die present invention is disclosed and explain in U.S. Pat. No. 5,295,196 and PCT application Serial No. PCT/US95/02992. FIGs. 3 and 4a-4c illustrated thresholding tests which may be peformed by the discriminator in conjunction widi determining the denominations of scanned bills. These figures are described in more detail in PCT application Serial No. PCT/US95/02992. In some embodiments of die present invention die operation of the discriminator is suspended when a bill such as a no call is to be flagged. In some embodiments e transport mechanism is brought to a halt so mat the flagged bill is die last bill deposited in an output receptacle or inspection station. The manner of suspending die operation of the discriminator and halting of the transport mechanism is explained in more detailed in U.S. Pat. No. 5,295,196 and PCT application Serial No. PCT/US95/02992. Referring now to Fig. 5, the mechanical portions of a currency scanning and counting machine 10 include a rigid frame formed by a pair of side plates 201 (only one shown), a pair of top plates 203a and 203b, and a lower front plate 204. The input receptacle region for receiving a stack of bills to be processed is formed by downwardly sloping and converging walls 205 and 206 which are parts of removable covers 207 and 208, respectively, that snap onto the frame. The rear wall 206 supports die removable input hopper 209 which includes a pair of vertically disposed side walls 210a and 210b (both shown in FIG. 1). To initiate the scanning process, currency bills are stacked on die bottom wall 205 and are stripped, one at a time, from the bottom of the stack. The bills are in turn, is supported across the side walls 201. The auxiliary feed wheels 220 project tiirough a pair of slots formed in the cover 207. Each auxiliary feed wheel 220 includes a raised high-friction, serrated surface 222 around a portion of the periphery which engages the bottom bill of the input stack as the auxiliary feed wheels 220 rotate to initiate the movement of the bottom bill from the stack. The serrated surface 222 projects radially beyond die rest of die wheel periphery so that the wheels "jog" the bill stack during each revolution so as to loosen die bottom currency bill within the stack and die bottom bill from the stack. The auxiliary feed wheels 220 move each stripped bill onto a drive roll 223 mounted on a driven shaft 224 supported across the side walls 201. To ensure firm engagement between the drive roll 223 and die currency bill being fed, an idler roll 230 urges each incoming bill against a smootii central surface of the drive roll 223. The idler roll 230 is journalled on a pair of arms which are pivotally mounted on a support shaft. A pair of stripping wheels 233 and 234 are also mounted on die shaft 232 on opposite sides of die idler roll 230. The grooves in these two stripping wheels 233, 234 are registered widi the central ribs in the two grooved surfaces of die drive roll 223. Although the idler roll 230 and the stripping wheels 233, 234 are mounted behind die guideway 211, the guideway 211 is apertured to allow die idler roll 230 and the stripping wheels 233, 234 to engage the bills on the front side of die guideway 211. To prepare die bills for scanning, die bills transported by die drive roll 223 engage a flat guide plate 240 on which a sensing device is mounted at die lower end of die curved guideway 211. Currency bills are positively driven along die flat plate 240 by means of a transport roll arrangement which includes die drive roll 223 at one end of die flat plate 240 and a smaller drive roll 241 at the other end of die plate. Botii the drive roll 223 and die smaller drive roll 241 include pairs of smooth raised cylindrical surfaces which hold die bill flat against the plate 240. A transport motor 260 drives both drive roll 223 and smaller drive roll 241 through a series of belts and pulleys. Additionally, die auxiliary feed wheels 220 are driven by the transport motor 260 via a pulley or belt attached on drive roll 223. A pair of O rings 245 (only one shown) fit into grooves formed in both die smaller drive roll 241 and die drive roll 223 to continuously engage the bill between the two rolls 223 and 241 and transport the bill while holding it flat against die guide plate 240. The flat guide plate 240 is provided widi openings through which d e raised surfaces of botii the drive roll 223 and die smaller driven roll 241 are subjected to counter-rotating contact widi corresponding pairs of passive transport rolls 250 and 251 having high-friction rubber surfaces. The passive rolls 250, 251 are mounted on die underside of die flat plate 240 in such a manner as to be freewheeling about their axes and biased into counter-rotating contact wid their corresponding drive rolls 223, 241. The passive rolls 250, 251 are biased into contact widi dieir corresponding drive rolls 223 and 241 by means of a pair of leaf springs 252, 253 (shown in FIG. 9). The points of contact between the drive rolls 223, 241 and passive rolls 250, 251 are preferably coplanar with the level surface of die flat plate 240 so that currency bills can be positively driven along die upper surface of die flat plate 240 in a smooth, flat manner. The distance between the axes of the two drive rolls 223 and 241 is selected to be just short of die length of the narrow dimension of the currency bills. Accordingly, die bills are firmly gripped under uniform pressure between both pairs of transport rolls, thereby minimizing the possibility of bills being skewed or twisted which enhances d e reliability of the overall scanning process. The sensing device which includes a pair of scanheads 18a and 18b is shown in detail in FIGS. 6, 7a, and 7b. It can be seen that the housing for each scanhead 18a and 18b is formed as an integral part of a unitary molded plastic support member 280 and 281. The lower member 281 forms the flat plate 240 that receives the bills from the drive roll 223 and supports the bills as they are driven past the scanheads 18a and 18b. Each of die two optical scanheads 18a and 18b housed in die support members 280, 281 includes a pair of light sources acting in combination to uniformly illuminate strips of a desired dimension on opposite sides of a bill as it is transported across die flat guide plate 240. Thus, the upper scanhead 18a includes a pair of LEDs 22a directing light downwardly tiirough an optical mask on top of a lens 282 onto a bill traversing the flat guide plate 240 beneath the scanhead 18a. Botii LEDs 22a are angularly disposed relative to the vertical axis of die upper scanhead 18a so that their respective light beams combine to illuminate the desired light strip defined by an aperture in the mask. The scanhead 18a also includes a photodetector 26a mounted directly over die center of the illuminated strip for sensing die light reflected off the strip. The photodetector 26a is linked to a CPU 30 (See Fig. 11) through an analog-to-digital convertor (ADC) for processing die sensed data. Similarly, the lower scanhead 18b which includes a pair of LEDs 22b, a lens 283, and a photodetector 26b communicates witii the CPU 30 through an ADC. The manner in which this data is processed is explained in detail in PCT patent application Serial No. PCT/US95/02992 which is incorporated herein by reference in its entirety. The upper member 280 and lower member 281 are mounted facing each other so that the lenses 282 and 283 of die two scanheads 18a, 18b define a narrow gap through which each bill is transported. Generally, the gap is approximately 0.025 inch when the machine is in the operational mode. The upper support member 280 includes a tapered entry guide 280a which guides an incoming bill into the gap between the opposed lenses 282 and 283. Doubling or overlapping of bills in the illustrative transport mechanism is detected by two additional photosensors which are located on a common transverse axis diat is perpendicular to die direction of bill flow. The photosensors include photodetectors 293 and 294 mounted witiiin the lower member 281 in immediate opposition to corresponding light sources 295 and 296 mounted in die upper member 280. The photodetectors 293, 294 detect beams of light directed downwardly onto the bill transport path from the light sources 295, 296 and generate analog outputs which correspond to die sensed light passing through the bill. Each such output is converted into a digital signal by a conventional ADC unit whose output is input to, and processed by, the CPU 30. The presence of a bill adjacent die photosensors causes a change in die intensity of the detected light, and die corresponding changes in the analog outputs of the photodetectors 293 and 294 serve as a convenient means for density-based measurements for detecting die presence of "doubles" (two or more overlaid or overlapped bills) during the currency scanning process. For instance, the photodetectors 293, 294 may be used to collect a predefined number of density measurements on a test bill, and die average density value for a bill may be compared to predetermined density tiiresholds (based, for instance, on standardized density readings for master bills) to determine the presence of overlaid bills or doubles. Thus, this density detecting system ensures that no more than one bill is being scanned at a time. Although the machine has been designed to greatly minimize the jamming of currency bills while being moved along die transport patii, situations arise in which the machine will become jammed, especially in the area of the scanheads 18a, 18b. For example, an older currency bill which is not as "crisp" as a newer bill tends to buckle when its leading edge engages die guiding members within the transport path, especially in the region adjacent d e sensing devices. As it begins to obstruct die transport path, the buckled bill in die transport padi loses its velocity. The bills trailing die buckled bill then come into contact with the buckled bill and cause die transport patii to become jammed. Additionally, currency bills with bent corners or a bill in the stack d at is folded can catch on edges along die transport patii as well. In any event, it is useful to have a simple means in which to clear a jam that may occur, especially beneath the upper member 280. The lower member 281 is attached rigidly to die machine frame. However, the upper member 280 is slidably mounted on a pair of posts 285 and 286 on die machine frame thereby providing limited vertical movement. A pair of springs 287 and 288 bias d e upper member 280 to its lowermost position in the operational mode. In one embodiment, a pair of handles 297 connected to upper member 280 are exposed once an access cover is opened. For example, removing the removable hopper 209 exposes the handles 297. Once exposed, die operator lifts die handles 297 by tiieir gripping portion 298 and moves the connecting portion 299 over a structure rigidly affixed to die frame. An engagement surface 299a dien engages the rigid structure to support the upper member 280. In FIG. 7b, the engagement surface 299a of each handle 297 is semi-circular and die structure to which it is connected is the shaft 221 which is also shown in Fig. 5. When positioned in this retracted position, the gap between the lenses 282 and 283 of die two scanheads 18a, 18b increases and is in the range from about 0.075 inch to about 0.20 inch. Generally, the handles 297 are flexible to allow them to be deflected in a direction parallel to the direction a currency bill moves along the transport path. Thus, when attaching the handles 297 to and detaching diem from the shaft 221 in FIGS. 7a and 7b, die operator can move the connecting portion 299 laterally across the shaft 221. Alternatively, the upper member 280 can be locked into the retracted position by a brace member which engages die posts 285, 286. Small handles connected to die upper member 280 near the posts 285, 286 are grasped to lift die upper member 280. When in the retracted position, die rigid brace member attached to die frame or handles is positioned between die posts 285, 286 and a portion of the handles which acts against the springs 287, 288 and restrains the upper member 280 from returning to the operational position. In another alternative, small handles having a profile similar to the handle 297 in FIGS. 7a and 7b could latch onto rigid structures attached to die frame near the posts 285, 286. In yet another alternative, the upper member 280 is separated from the lower member 281 without removing any access cover like the removable hopper 209. The operator moves a lever which is connected to one of die members 280, 281 and is exposed on die exterior of the machine. The movement of the lever then increases the gap between the two members 280, 281. For example, the lever is attached to a cam which when rotated forces the two members 280, 281 apart. In yet a further alternative, the upper member 280 could be automatically converted between die operational position and die retracted position by use of a pair of solenoids 300, 302 as shown in Fig. 8. The solenoids 300, 302 are affixed onto the rigid frame near the posts 285, 286. Each solenoid 300, 302 has a displacing member 304 which attaches to the upper member 280. When energized, the displacing member 304 of e solenoids 300, 302 act against the force of the springs 286, 287 and move the upper member 280 from the operational position to the retracted position. Altiiough die solenoids 300, 302 are shown attached to die upper member 280, they can also be attached to the lower member 281. In such an embodiment, the solenoids 300, 302 dien push the upper member 280 away from the lower member 281 against the force of the springs 287, 288. Fig. 9 shows a bottom plan view of the lower member 281 of the scanning device and die passive transport rolls 250, 251. Fig. 10 illustrates a bottom plan view of the upper member 280 including die upper scanhead 18. Botii figures are applicable to the scanning device illustrated in Fig. 6 or 5. As shown in Fig. 11, die CPU 30 of die machine 10 is coupled to various components within the jam detection and clearing mechanism. The CPU 30 is coupled to a memory device 38 and receives inputs froift a crystal 40 which serves as the time base for the CPU 30. The CPU 30 also receives operator input signals from the keypad 62 on die control panel 61 and provides the user with information via the display 63 on die control panel 61. The CPU 30 also controls the operation of both the stacker motor 261 and die transport mechanism motor 260. Wim respect to the detection of a jam which is described in detail below in reference to FIGS. 13a-13c, die CPU 30 processes die output of the denomination sensors 26a, 26b and d e density sensors 293, 294. The outputs of both of these sensors are converted to digital signals by standard ADCs before being received by the CPU 30. Also, the CPU 30 monitors the velocity of the drive shaft or the transport mechanism via the encoder 32 which is described in detail below. Additionally, die CPU 30 monitors a hopper sensor 42 placed adjacent die removable hopper 209 which indicates whetiier the hopper 209 is installed or detached from the machine 10. Once the lower member 281 and die upper member 280 are separated, me jammed currency bill must still be removed from the transport path. This is accomplished by operating die bill transport mechanism in a reverse or forward motion to clear the jammed bill. As shown in Fig. 12, the control panel 61 (also shown in FIG. 1) includes die display 63 as well as die keypad 62 having a plurality of keys actuated by die operator to perform various functions. A reverse key 67 and a forward key 68 on die keypad 62 send a reverse signal and a forward signal, respectively, to the CPU 30 which instructs the transport mechanism to operate in the reverse or forward mode. Thus, when die operator actuates die reverse key 67, the CPU 30 receives a reverse signal and instructs die transport motor 260 to rotate in a reverse direction. The jammed currency bill dien moves back tiirough the guideway 211 and can be accessed at the opening near wall 205 adjacent die nips formed by roll 223 and stripping wheels 233, 234 as shown in Fig. 5. If the jammed currency bill is not accessible after actuation of die reverse key 67, then the operator can activate the forward key 68 to attempt to move the jammed bill forward. This will result in die currency bill being accessible at the output receptacle 217. No data is processed at this point and die jammed bill must be returned to die stack. The operator dien returns the upper member 280 to the operational position by utilizing the handles 297 or activating a key on the control panel 261 if the separation of the members 280, 281, occurs via solenoids. Alternatively, die machine can include a manual turn-knob which is connected to die drive shaft 221 of the drive roll 223 instead of utilizing the reverse key 67 and die forward key 68. After the members 280, 281 are separated, the operator then manually turns die knob in a forward or reverse direction to transport die jammed currency bill along the transport path and clear the jam. FIGS. 13a- 13c are flow charts which illustrate the process in which a jammed bill is detected and die resultant actions by die operator and die machine. After a bill becomes jammed along the transport path (step 400), the machine detects die jam (step 401). Three examples of ways the machine may accomplish this task include die following. First, if the time required for a currency bill to pass by one of die density photodetector sensors 293, 294 exceeds a tiireshold limit, then a jam has likely occurred. Second, if die time required for a bill to pass through the currency denomination photodetectors 26a and 26b exceeds a threshold limit, men a jam is probable. Generally, these upper threshold limits are approximately 0.25 second (die normal time required for a bill to pass by one of tiiese sensors is approximately 0.025 second). The tiiird method by which a jam can be detected is by monitoring the encoder 32 which indicates die shaft speed of die transport motor 260 powering the transport mechanism. More specifically, the optical encoder 32 is linked to die output shaft of die transport motor 260 which drives the transport mechanism that moves the bill along the transport path. The optical encoder 32 sends signals to die CPU 30 corresponding to successive increments of angular displacement of die drive shaft of die transport motor 260. Thus, if the signals received by die CPU 30 from the encoder 32 drop below a threshold limit in a selected time period, dien the shaft speed of the transport motor 260 has been reduced by die occurrence of the jam which increases the load on die transport motor 260 Once die CPU 30 receives a jam signal from any of these three jam detection mechanisms, the transport motor 260 is disabled by die CPU 30. The CPU 30 dien sends a signal to die display 63 on die control panel 61 which informs the operator that a jam has been detected (step 402). To access and lift die handles 297 to relieve the pressure applied to die jammed bill by die transport mechanism, the operator must remove the hopper tray 209 (step 403). The hopper sensor 42 (in Fig. 11) is positioned adjacent die hopper tray 209 and detects whetiier the hopper tray 209 is in position. If the CPU 30 determines the hopper tray 209 has been removed (step 404), then the display 63 on die control panel 61 instructs the operator to lift the handles 297 and position their engagement surfaces 299a over the drive shaft 221 (step 406). After lifting the handles 297 and attaching diem to the feed shaft (step 407), d e upper member 280 and lower member 281 are now in die retracted position, and d e operator can begin the process of removing the jammed bill from me transport path. If an automatic separation technique is utilized, such die solenoids 300, 302 described above in connection with Fig. 8, then steps 403-407 are obviated. The operator uses the keys on the control panel 61 to activate the transport mechanism and remove the jammed bill. If die operator chooses die forward key 267 (step 408), die machines starts the stacker motor 216 since the bill will be expelled near the output receptacle by the stacker wheels 212, 213 (step 410). The transport motor 260 driving the transport mechanism is then run at full forward speed for 0.25 second (step 412) to remove the jammed bill and dien for an additional 1.25 seconds at half forward speed (step 414). The stacker motor 216 and die transport motor 260 are then stopped (step 416) and the operator removes the formerly jammed bill from the output receptacle (step 418). The operator can also choose the reverse key 267 on the control panel 61 when attempting to remove a jammed bill (step 420). Because die reverse mode will not result in die bill being expelled from the output receptacle, there is no need to activate die stacker motor 216. The transport motor 260 driving the transport mechanism is then run at full reverse speed for 0.25 second (step 422) and dien at half speed reverse for an additional 1.25 seconds to remove the jammed bill to die input receptacle. The transport motor 260 is men stopped (step 426) and die operator removes the formerly jammed bill from the input receptacle (step 428). The operator can continuously alternate between the reverse key 67 and die forward key 68 until the jammed bill is successfully removed. Once die formerly jammed bill is retrieved, the operator then grasps the handles 297 and returns die upper member 280 to its operational position (step 430). The machine may also have a sensor which detects whetiier the upper member 280 is in the retracted position. For example, a switch which is activated only when die upper member 280 is in the retracted position may be employed. Alternatively, die amount of light received by die density photodetectors 293, 294 depends on tiieir distance from the light source. Thus, the retracted position can be distinguished from the operational position by die density photodetectors 293, 294 assuming the jammed bill is cleared. Thus, the CPU 30 can then prompt the operator to perform the next steps in the procedure based on whetiier the upper member 280 is in the operational or retracted position. The operator returns the hopper tray 209 to its normal position (step 432) and selects a continue key 65 (step 434) on die control panel 61 (shown in Fig. 12). The machine then checks die density photodetectors 293, 294 and die currency denomination photodetectors 26a and 26b to ensure that the jam has been completely cleared (step 436). If die machine still detects die presence of a jammed bill, men the machine performs the entire clearance process again. If no bill is detected, dien the display 63 returns to its normal counting mode (step 438) and all totals are reset to die recorded amount prior to the processing of the initial bill in the stack of bills which produced the jam (step 440). The operator then gathers all bills in the stack which produced die jam from the output receptacle and the input receptacle including die jammed bills, and returns diem as a stack to the input receptacle to be recounted and rediscriminated (step 441). The stacker motor 216 and the transport motor 260 are then started (step 442) and die CPU 30 begins to run the main programming loop (step 444). Currency bills in the input receptacle will now be transported by die transport mechanism and undergo die scanning process. Fig. 14 is a functional block diagram illustrating another embodiment of a currency discriminator system 1662 according to die present invention. The discriminator system 1662 comprises an input receptacle 1664 for receiving a stack of currency bills. A transport mechanism defining a transport patii (as represented by arrows A and B) transports the bills in the input receptacle past one or more sensors of an authenticating and discriminating unit 1666 to an output receptacle 1668 where the bills are re-stacked such that each bill is stacked on top of or behind die previous bill so tiiat die most recent bill is the top-most or rear-most bill. The authenticating and discriminating unit scans and determines the denomination of each passing bill. Any variety of discriminating techniques may be used. For example, the discriminating method disclosed in U.S. Pat. No. 5,295,196 (incorporated herein in its entirety) may be employed to optically scan each bill. Depending on die characteristics of the discriminating unit employed, die discriminator may be able to recognize bills only if fed face up or face down, regardless of whetiier fed face up or face down, only if fed in a forward orientation or reverse orientation, regardless of whetiier fed in a forward or reverse orientation, or some combination thereof. Additionally, die discriminating unit may be able to scan only one side or both sides of a bill. In addition to determining the denomination of each scanned bill, the authenticating and discriminating unit 1666 may additionally include various authenticating tests such as an ultraviolet authentication test as disclosed in PCT patent application Serial No. PCT/US95/02992. Signals from the autiienticating and discriminating unit 1666 are sent to a signal processor such as a central processor unit ("CPU") 1670. The CPU 1670 records of results of die autiienticating and discriminating tests in a memory 1672. When the authenticating and discriminating unit 1666 is able to confirm the genuineness and denomination of a bill, the value of me bill is added to a total value counter in memory 1672 that keeps track of die total value of d e stack of bills that were inserted in die input receptacle 1664 and scanned by die autiienticating and discriminating unit 1666. Additionally, depending on the mode of operation of the discriminator system 1662, counters associated witii one or more denominations are maintained in die memory 1672. For example, a $1 counter may be maintained to record how many $1 bills were scanned by die authenticating and discriminating unit 1666. Likewise, a $5 counter may be maintained to record how many $5 bills were scanned, and so on. In an operating mode where individual denomination counters are maintained, d e total value of the scanned bills may be determined without maintaining a separate total value counter. The total value of the scanned bills and/or die number of each individual denomination may be displayed on a display 1674 such as a monitor or LCD display. As discussed above, a discriminating unit such as die autiienticating and discriminating unit 1666 may not be able to identify the denomination of one or more bills in the stack of bills loaded into die input receptacle 1664. For example, if a bill is excessively worn or soiled or if the bill is torn a discriminating unit may not be able to identify the bill. Furthermore, some known discrimination methods do not have a high discrimination efficiency and thus are unable to identify bills which vary even somewhat from an "ideal" bill condition or which are even somewhat displaced by die transport mechanism relative to the scanning mechanism used to discriminate bills. Accordingly, such poorer performing discriminating units may yield a relatively large number of bills which are not identified. Alternatively, some discriminating units may be capable of identifying bills only when they are fed in a predetermined manner. For example, some discriminators may require a bill to be faced in a predetermined manner. Accordingly, when a bill is fed face down past a discriminating unit which can only identify bills fed face up, the discriminating unit can not identify die bill. Likewise, odier discriminators require a specific edge of a bill to be fed first, for example, the top edge of a bill. Accordingly, bills which are not fed in me forward direction, that is, those that are fed in die reverse direction, are not identified by such a discriminating unit. According to one embodiment, die discriminator system 1662 is designed so tiiat when the authenticating and discriminating unit is unable to identify a bill, die transport mechanism is stopped so tiiat the unidentified bill is die last bill transported to die output receptacle. After die transport mechanism stops, the umdentified bill is then, for example, positioned at die top of or at the rear of the stack of bills in the output receptacle 1668. The output receptacle 1668 is preferably positioned witiiin the discriminator system 1662 so that the operator may conveniently see the flagged bill and/or remove it for closer inspection. Accordingly, the operator is able to easily see die bill which has not been identified by die autiienticating and discriminating unit 1666. The operator may then either visually inspect the flagged bill while it is resting on the top of or at the rear of the stack, or alternatively, the operator may chose to remove the bill from the output receptacle in order to examine me flagged bill more closely. The discriminator system 1662 may be designed to continue operation automatically when a flagged bill is removed from the output receptacle or, according to one embodiment of the present invention, may be designed to require a selection element to be depressed. Upon examination of a flagged bill by the operator, it may be found tiiat the flagged bill is genuine even though is was not identified by the discriminating unit. However, because the bill was not identified, die total value and/or denomination counters in the memory 1672 will not reflect its value. According to one embodiment, such an unidentified bill is removed from the output stack and eitiier re-fed tiirough the discriminator or set aside. In die latter case, any genuine set aside bills are counted by hand. In some discriminators, unidentified bills are routed to a separate reject receptacle. In prior such systems, an unidentified genuine bill would have to be removed from a reject receptacle and re-fed tiirough the discriminator or the stack of rejected bills would have to be counted by hand and the results separately recorded. Furthermore, because re-fed bills have gone unidentified once, they are more likely to go unidentified again and ultimately may have to be counted by hand. However, as discussed above, such procedures may increase the chance for human error or at least lower the efficiency of the discriminator and die operator. In order to avoid problems associated wid re-feeding bills, counting bills by hand, and adding togedier separate totals, according to one embodiment of me present invention a number of selection elements associated with individual denominations are provided. In FIGs. 1 and 14, tiiese selection elements are in the form of keys or buttons of a keypad 1676. Other types of selection elements such as switches or displayed keys in a touch-screen environment may be employed. The operation of the selection elements will be described in more detail in connection with Fig. 17 but briefly when an operator determines tiiat a flagged bill is acceptable, die operator may simply depress die selection element associated with the denomination of die flagged bill and die corresponding denomination counter and/or die total value counter are appropriately incremented and die discriminator system 1662 or 10 resumes operating again. As discussed above, a bill may be flagged for any number of reasons including the bill being a no call or suspect bill. In non-automatic restart discriminators, where an operator has removed a genuine flagged bill from the output receptacle for closer examination, the bill is first replaced into the output receptacle before a corresponding selection element is chosen. An advantage of die above described procedure is tiiat appropriate counters are incremented and die discriminator is restarted witii the touch of a single key, greatly simplifying the operation of the discriminator system 1662 or 10 while reducing die opportunities for human error. When an operator determines that a flagged bill is not acceptable, die operator may remove die unacceptable flagged bill from the output receptacle without replacement and depress a continuation key on the keypad 1676 or 62. When die continuation key is selected die denomination counters and die total value counter are not affected and die discriminator system 1662 or 10 will resume operating again. In automatic restart discriminators, the removal of a bill from the output receptacle is treated as an indication tiiat the bill is unacceptable and die discriminator automatically resumes operation widiout affecting the denomination counters and/or total value counters. Turning now to Fig. 15, there is shown a functional block diagram illustrating another embodiment of a document autiienticator and discriminator according to die present invention. The discriminator system 1680 comprises an input receptacle 1682 for receiving a stack of currency bills. A transport mechanism defining a transport path (as represented by arrow C) transports die bills in die input receptacle, one at a time, past one or more sensors of an autiienticating and discriminating unit 1684. Based on die results of the autiienticating and discriminating unit 1684, a bill is either transported to one of a plurality of output receptacles 1686 (arrow D), to a reject receptacle 1688 (arrow E), or to an operator inspection station 1690 (arrow F). When is bill is determined to be genuine and its denomination has been identified, die bill is transported to one of a plurality of output receptacles. For example, the discriminator system 1680 may comprise seven output receptacles 1686, one associated witii each of seven U.S. denominations, i.e., $1, $2, $5, $10, $20, $50, and $100. The transport mechanism directs (arrow D) die identified bill to die corresponding output receptacle. Alternatively, where d e autiienticating and discriminating unit determines that a bill is a fake, the bill is immediately routed (arrow E) to the reject receptacle 1688. Finally, if a bill is not determined to be fake but for some reason die autiienticating and discriminating unit 1684 is not able to identify die denomination of the bill, the flagged bill is routed (arrow F) to an inspection station and die discriminator system 1680 stops operating. The inspection station is preferably positioned witiiin the discriminator system 1680 so tiiat the operator may conveniently see the flagged bill and/or remove it for closer inspection. If the operator determines that the bill is acceptable, the operator returns the bill to the inspection station if it was removed and selects a selection element (not shown) corresponding to die denomination of the flagged bill. Appropriate counters (not shown) are incremented, die discriminator system 1680 resumes operation, and the flagged bill is routed (arrow G) to the output receptacle associated witii the chosen selection element. On the other hand, if die operator determines that the flagged bill is unacceptable, die operator returns the bill to the inspection station if it was removed and selects a continuation element (not shown). The discriminator system 1680 resumes operation, and die flagged bill is routed (arrow H) to die reject receptacle 1688 widiout incrementing the counters associated widi die various denomination and/or die total value counters. Alternatively, the discriminator system 1680 may permit the operator to place any unacceptable unidentified bills aside or into die reject receptacle by hand. While transport patiis D and G and paths E and H are illustrated as separate paths, paths D and G and paths E and H, respectively, may be the same path so that all bills proceeding to eitiier one of the output receptacles 1686 or the reject receptacle 1688, respectively, are routed tiirough the inspection station 1690. Turning now to Fig. 16a, there is shown a functional block diagram illustrating anodier embodiment of a document autiienticator and discriminator according to die present invention. The discriminator system 1692 comprises an input receptacle 1694 for receiving a stack of currency bills. A transport mechanism (as represented by arrow I) transports the bills in the input receptacle, one at a time, past one or more sensors of an authenticating and discriminating unit 1696. Based on die results of die autiienticating and discriminating unit 1684, a bill is either transported to a single output receptacle 1698 (arrow J) or to an operator inspection station 1699 (arrow K). When is bill is determined to be genuine and its denomination has been identified, die bill is transported to the single output receptacle. Alternatively, where the authenticating and discriminating unit determines that a bill is a fake or for some reason the authenticating and discriminating unit 1684 is not able to identify die denomination of the bill, the flagged bill is routed (arrow K) to an inspection station and die discriminator system 1692 stops operating. The inspection station is preferably positioned witiiin the discriminator system 1692 so that the operator may conveniently see the flagged bill and/or remove it for closer inspection. Where a bill has been positively determined to be a fake by die autiienticating and discriminating unit 1696, an appropriate indication, for example, via a message in a display or the illumination of a light, can be given to the operator as to the lack of genuineness of the bill. The operator may then remove the bill widiout replacement from the inspection station 1699 and select a continuation element. Where a bill has not been positively identified as a fake nor has had its denomination identified and where die operator determines that the bill is acceptable, the operator returns the bill to the inspection station if it was removed and selects a selection element (not shown) corresponding to die denomination of die flagged bill. Appropriate counters (not shown) are incremented, die discriminator system 1692 resumes operation, and die flagged bill is routed (arrow L) to the single output receptacle 1698. On the other hand, if die operator determines that the flagged bill is unacceptable, die operator removes the bill without replacement form the inspection station and selects a continuation element (not shown). The discriminator system 1692 resumes operation without incrementing the counters associated with die various denomination and/or the total value counters. While transport paths J and L are illustrated as separate patiis, they may be the same path so that all bills proceeding to d e single output receptacle 1698 are routed tiirough the inspection station 1699. Turning now to Fig. 16b, there is shown a functional block diagram illustrating another embodiment of a document authenticator and discriminator according to the present invention. The discriminator system 2202 comprises an input receptacle 2204 for receiving a stack of currency bills. A transport mechanism defining a transport patii (as represented by arrow M) transports die bills in die input receptacle, one at a time, past one or more sensors of an authenticating and discriminating unit 2206. Bills are then transported to one of a plurality of output receptacles 2208 (arrow N). In one embodiment, where the authenticating and discriminating unit determines mat a bill is a fake, the flagged bill is routed to a separate one of said output receptacles. The operation of the discriminator may or may not then be suspended. When a bill is not determined to be fake but for some reason the authenticating and discriminating unit 1684 is not able to identify the denomination of me bill, the no call bill may be transported one of die output receptacles. In one embodiment, no call bills are transported to a separate one of the output receptacles. In another embodiment, no calls are not delivered to a special separate output receptacle. The operation of the discriminator may or may not then be suspended. For example, in a two output pocket discriminator, all bills may be transported to die same output receptacle regardless of whetiier they are determined to be suspect, no call, or properly identified. In this example, the operation of the discriminator may be suspended and an appropriate message displayed when a suspect or no call bill is encountered. Alternatively, suspect bills may be delivered to one of d e output receptacles (i.e., a reject receptacle) and no calls and identified bills may be sent to the other output receptacle. In this example, the operation of the discriminator need not be suspended when a suspect bill is encountered but may be suspended when a no call bill is encountered. If die operation is suspended at die time me no call bill is detected and die operator determines that d e no call bill is acceptable, die operator returns the bill to the output receptacle from which it was removed (if it was removed) and selects a selection element (not shown) corresponding to die denomination of the flagged bill. Appropriate counters (not shown) are incremented, the discriminator system 2202 resumes operation. On the other hand, if die operator determines that the flagged bill is unacceptable, die operator removes the bill without replacement form the output receptacle and selects a continuation element (not shown). The discriminator system 2202 resumes operation without incrementing the counters associated with die various denomination and/or die total value counters. In another embodiment, no call bills are delivered to an output receptacle separate from the one or more output receptacles receiving identified bills. The operation of the discriminator need not be suspended until all the bills placed in the input receptacle have been processed. The value of any no call bills may then be added to die appropriate counters after the stack of bills has been processed tiirough a reconciliation process. The entering of the value of no call bills is discussed in more detail below in connection widi FIGs. 19-24. The operation of the selection elements according to one embodiment will now be described in more detail in conjunction with Fig. 17 which is a front view of a control panel 61 of one embodiment of the present invention. The control panel 61 comprises a keypad 62 and a display section 63. The keypad 62 comprises a plurality of keys including seven denomination selection elements 64a-64g, each associated with one of seven U.S. currency denominations, i.e., $1, $2, $5, $10, $20, $50, and $100. For foreign bill discriminators, die denomination selection elements may be labeled according to die currency system which a discriminator is designed to handle and accordingly, tiiere may be more or less than seven denomination selection elements. The $1 denomination selection key 64a also serves as a mode selection key. The keypad 62 also comprises a "Continuation" selection element 65. Various information such as instructions, mode selection information, authentication and discrimination information, individual denomination counter values, and total batch counter value are communicated to die operator via an LCD 66 in die display section 63. A discriminator according to one embodiment of the present invention has a number of operating modes including a mixed mode, a stranger mode, a sort mode, a face mode, and a forward/reverse orientation mode. The operation of a discriminator having the denomination selection elements 64a-64g and the continuation element 65 will now be discussed in connection with several operating modes. (A) Mixed Mode Mixed mode is designed to accept a stack of bills of mixed denomination, total die aggregate value of all die bills in die stack and display the aggregate value in the display 63. Information regarding the number of bills of each individual denomination in a stack may also be stored in denomination counters. When an otherwise acceptable bill remains unidentified after passing through the authenticating and discriminating unit, operation of die discriminator may be resumed and die corresponding denomination counter and/or die aggregate value counter may be appropriately incremented by selecting the denomination selection key 64a-64g associated widi die denomination of the unidentified bill. For example, if the discriminator system 62 of Fig. 14 or 10 of FIG. 1 stops operation with an otherwise acceptable $5 bill being the last bill deposited in the output receptacle, the operator may simply select key 64b. When key 64b is depressed, die operation of the discriminator is resumed and die $5 denomination counter is incremented and/or die aggregate value counter is incremented by $5. Furthermore, in the discriminator systems 1680 of Fig. 15 and 1692 of Fig. 16, die flagged bill may be routed from the inspection station to an appropriate output receptacle. Otherwise, if the operator determines the flagged bill is unacceptable, the bill may be removed from the output receptacle of FIGs. 1 or 14 or the inspection station of FIGs. 15 and 16a (or in die system 1680 of Fig. 15, the flagged bill may be routed to die reject receptacle 1688). The continuation key 65 is depressed after the unacceptable bill is removed, and die discriminator resumes operation without affecting the total value counter and/or die individual denomination counters. (B) Stranger Mode Stranger mode is designed to accommodate a stack of bills all having the same denomination, such as a stack of $10 bills. In such a mode, when a stack of bills is processed by die discriminator the denomination of the first bill in the stack is determined and subsequent bills are flagged if they are not of the same denomination. Alternatively, die discriminator may be designed to permit the operator to designate die denomination against which bills will be evaluated witii those of a different denomination being flagged. Assuming the first bill in a stack determines the relevant denomination and assuming the first bill is a $10 bill, then provided all die bills in die stack are $10 bills, the display 63 will indicate die aggregate value of the bills in the stack and/or die number of $10 bills in the stack. However, if a bill having a denomination other dian $10 is included in die stack, die discriminator will stop operating with the non-$10 bill or "stranger bill" being the last bill deposited in the output receptacle in the case of the discriminator system 62 of Fig. 14 or 10 of FIG. 1 (or the inspection station of FIGs. 15 and 16a). The stranger bill may then be removed from the output receptacle and die discriminator is started again either automatically or by depression of the "Continuation" key 65 depending on die set up of the discriminator system. An unidentified but otiierwise acceptable $10 bill may be handled in a manner similar to tiiat described above in connection widi die mixed mode, e.g., by depressing die $10 denomination selection element 64c, or alternatively, the unidentified but otherwise acceptable $10 bill may be removed from the output receptacle and placed into the input hopper to be re-scanned. Upon die completion of processing the entire stack, the display 63 will indicate die aggregate value of the $10 bills in the stack and/or the number of $10 bills in the stack. All bills having a denomination other than $10 will have been set aside and will not be included in die totals. Alternatively, these stranger bills can be included in die totals via operator selection choices. For example, if a $5 stranger bill is detected and flagged in a stack of $10 bills, d e operator may be prompted via the display as to whether the $5 bill should be incorporated into die running totals. If die operator responds positively, die $5 bill is incorporated into appropriate running totals, otiierwise it is not. Alternatively, when the discriminator stops on a stranger bill, such as a $5, the operator may depress the denomination selection element associated witii that denomination to cause die value of the stranger bill to be incorporated into die totals. Likewise for other types of flagged bills such as no calls. Alternatively, a set-up selection may be chosen whereby all stranger bills are automatically incorporated into appropriate running totals. (C. Sort Mode According to one embodiment, the sort mode is designed to accommodate a stack of bills wherein die bills are separated by denomination. For example, all die $1 bills may be placed at the beginning of die stack, followed by all die $5 bills, followed by all die $10 bills, etc. Alternatively, the sort mode may be used in conjunction witii a stack of bills wherein the bills are mixed by denomination. The operation of the sort mode is similar to that of the stranger mode except tiiat after stopping upon the detection of a different denomination bill, the discriminator is designed to resume operation upon removal of all bills from the output receptacle. Returning to the above example, assuming the first bill in a stack determines the relevant denomination and assuming the first bill is a $1 bill, then the discriminator processes the bills in the stack until the first non-$l bill is detected, which in this example is the first $5 bill. At that point, the discriminator will stop operating witii the first $5 being the last bill deposited in die output receptacle. The display 63 may be designed to indicate die aggregate value of the preceding $1 bills processed and/or die number of preceding $1 bills. The scanned $1 bills and die first $5 bill are removed from the output receptacle and placed in separate $1 and $5 bill stacks. The discriminator will start again automatically and subsequent bills will be assessed relative to being $5 bills. The discriminator continues processing bills until d e first $10 bill is encountered. The above procedure is repeated and die discriminator resumes operation until encountering the first bill which is not a $10 bill, and so on. Upon d e completion of processing the entire stack, the display 63 will indicate die aggregate value of all die bills in e stack and/or die number of bills of each denomination in die stack. This mode permits the operator to separate a stack of bills having multiple denominations into separate stacks according to denomination. (D Face Mode Face mode is designed to accommodate a stack of bills all faced in die same direction, e.g. , all placed in the input hopper face up (that is the portrait or black side up for U.S. bills) and to detect any bills facing the opposite direction. In such a mode, when a stack of bills is processed by die discriminator, die face orientation of die first bill in the stack is determined and subsequent bills are flagged if tiiey do not have the same face orientation. Alternatively, the discriminator may be designed to permit designation of die face orientation to which bills will be evaluated with those having a different face orientation being flagged. Assuming the first bill in a stack determines the relevant face orientation and assuming the first bill is face up, then provided all the bills in the stack are face up, the display 63 will indicate die aggregate value of the bills in the stack and/or die number of bills of each denomination in the stack. However, if a bill faced in the opposite direction (i.e., face down in this example) is included in die stack, the discriminator will stop operating witii the reverse-faced bill being die last bill deposited in d e output receptacle. The reverse-faced bill dien may be removed from the output receptacle. In automatic re-start embodiments, the removal of the reverse-faced bill causes die discriminator to continue operating. The removed bill may then be placed into die input receptacle with the proper face orientation. Alternatively, in non-automatic re¬ start embodiments, the reverse-faced bill may be either placed into die input receptacle widi die proper face orientation and die continuation key 65 depressed, or placed back into die output receptacle with the proper face orientation. Depending on die set up of die discriminator when a bill is placed back into the output receptacle with the proper face orientation, the denomination selection key associated witii the reverse-faced bill may be selected, whereby the associated denomination counter and/or aggregate value counter are appropriately incremented and die discriminator resumes operation. Alternatively, in embodiments wherein the discriminator is capable of determining denomination regardless of face orientation, the continuation key 65 or a third key may be depressed whereby the discriminator resumes operation and die appropriate denomination counter and/or total value counter is incremented in accordance widi the denomination identified by die discriminating unit. In discriminators that require a specific face orientation, any reverse-faced bills will be unidentified bills. In discriminators mat can accept a bill regardless of face orientation, reverse-faced bills may be properly identified. The later type of discriminator may have a discriminating unit with a scanhead on each side of die transport path. Examples of such dual-sided discriminators are disclosed above (see e.g. , FIGs. 2, 5, and 6. The ability to detect and correct for reverse-faced bills is important as me Federal Reserve requires currency it receives to be faced in the same direction. In a multi-output receptacle discriminator, the face mode may be used to route all bills facing upward to one output receptacle and all bills facing downward to anodier output receptacle. In single-sided discriminators, reverse-faced bills may be routed to an inspection station such as 1690 of Fig. 15 for manual turnover by the operator and the unidentified reverse-faced bills may dien be passed by die discriminator again. In dual-sided discriminators, identified reverse-faced bills may be routed directly to an appropriate output receptacle. For example, in dual-sided discriminators bills may be sorted botii by face orientation and by denomination, e.g., face up $1 bills into pocket #1, face down $1 bills into pocket #2, face up $5 bills into pocket #3, and so on or simply by denomination, regardless of face orientation, e.g., all $1 bills into pocket #1 regardless of face orientation, all $2 bills into pocket #2, etc. (E) Forward/Reverse Orientation Mode Forward/Reverse Orientation mode ("Orientation" mode) is designed to accommodate a stack of bills all oriented in a predetermined forward or reverse orientation direction. For example in a discriminator tiiat feeds bills along dieir narrow dimension, the forward direction may be defined as die fed direction whereby the top edge of a bill is fed first and conversely for the reverse direction. In a discriminator that feeds bills along their long dimension, die forward direction may be defined as die fed direction whereby the left edge of a bill is fed first and conversely for die reverse direction. In such a mode, when a stack of bills is processed by die discriminator, the forward/reverse orientation of the first bill in the stack is determined and subsequent bills are flagged if tiiey do not have die same forward/reverse orientation. Alternatively, the discriminator may be designed to permit the operator to designate die forward/reverse orientation against which bills will be evaluated witii tiiose having a different forward/reverse orientation being flagged. Assuming the first bill in a stack determines the relevant forward/reverse orientation and assuming the first bill is fed in the forward direction, then provided all d e bills in the stack are also fed in the forward direction, die display 63 will indicate die aggregate value of the bills in the stack and/or die number of bills of each denomination in die stack. However, if a bill having die opposite forward/reverse orientation is included in the stack, die discriminator will stop operating with the opposite forward/reverse oriented bill being die last bill deposited in the output receptacle. The opposite forward/reverse oriented bill d en may be removed from me output receptacle. In automatic re-start embodiments, the removal of the opposite forward/reverse oriented bill causes the discriminator to continue operating. The removed bill may then be placed into the input receptacle with the proper face orientation. Alternatively, in non-automatic re-start embodiments, the opposite forward/reverse oriented bill may be either placed into the input receptacle with the proper forward/reverse orientation and die continuation key 65 depressed, or placed back into the output receptacle with the proper forward/reverse orientation. Depending on die set up of die discriminator when a bill is placed back into die output receptacle witii the proper forward/reverse orientation, die denomination selection key associated witii the opposite forward/reverse oriented bill may be selected, whereby the associated denomination counter and/or aggregate value counter are appropriately incremented and die discriminator resumes operation. Alternatively, in embodiments wherein the discriminator is capable of determining denomination regardless of forward/reverse orientation, the continuation key 65 or a the third key may be depressed whereby the discriminator resumes operation and die appropriate denomination counter and/or total value counter is incremented in accordance widi die denomination identified by die discriminating unit. In single- direction discriminators, any reverse-oriented bills will be unidentified bills. In dual- direction discriminators, reverse-oriented bills may be properly identified by die discriminating unit. An example of a dual-direction discriminating system is described above connection with FIGs. 1-2 and in United States Pat. No. 5,295,196. The ability to detect and correct for reverse-oriented bills is important as die Federal Reserve may soon require currency it receives to be oriented in the same forward/reverse direction. In a multi-output receptacle discriminator, the orientation mode may be used to route all bills oriented in die forward direction to one output receptacle and all bills oriented in the reverse direction to another output receptacle. In single-direction discriminators, reverse-oriented bills may be routed to an inspection station such as 1690 of Fig. 15 for manual turnover by the operator and die unidentified reverse- oriented bills may then be passed by die discriminator again. In discriminators capable of identifying bills fed in botii forward and reverse directions ("dual-direction discriminators"), identified reverse-oriented bills may be routed directly to an appropriate output receptacle. For example, in dual-direction discriminators bills may be sorted botii by forward/reverse orientation and by denomination, e.g., forward $1 bills into pocket #1, reverse $1 bills into pocket #2, forward $5 bills into pocket #3, and so on or simply by denomination, regardless of forward/reverse orientation, e.g., all $1 bills into pocket #1 regardless of forward/reverse orientation, all $2 bills into pocket #2, etc. (F) Off-Sort Mode Fig. 18 is a flow chart illustrating the sequential procedure involved in die performing a sorting operation according to an embodiment of the present invention. The operator of a currency discriminating device embodying a sorting method in accordance with the present invention selects a desired denomination to be off-sorted. A stack of currency to be processed is dien placed in die input receptacle of die discriminator and d e discriminator begins processing the bills. The discriminator determines the denomination of each bill in the stack. A bill whose denomination die discriminator is unable to determine to a requisite degree of certainty is termed a no call bill. The discriminator may also incorporate various authentication means. A bill failing one or more authentication tests is termed a suspect bill. The procedure of Fig. 18 begins at subroutine step 100 and it is first determined whetiier the discriminator is expecting the current bill to be a bill having the desired or specified denomination (step 102). If the answer is no, processing proceeds to step 104 where it is determined whether the current bill is a bill of the desired denomination. If me answer is no, d e value of die current bill is added to die total (step 106) and die subroutine is ended (step 108). If die answer is yes, die next bill is also expected to be a bill of die desired denomination and accordingly a flag bit is set indicating that the next bill is expected to be a bill of die desired denomination (step 110). Subsequently, a denomination change message is displayed (step 112) and a flag is set causing die discriminator to halt operation with die current bill being the last bill deposited in die output receptacle (step 114). A flag may be set to handle d e processing of the first bill in d e stack so that the discriminator will not halt if die first bill has the specified denomination. The denomination change message indicates why die discriminator has stopped operating and aids in distinguishing from other reasons why the discriminator may have stopped such as die detection of a no call or suspect bill. According to one embodiment, when the discriminator flags a bill, the bill immediately upstream of the flagged bill is scanned by die discriminator before the discriminator halts and die flagged bill is die last bill output to the output receptacle. The value of the current bill is added to die total (step 106) and die subroutine is ended (step 108). Returning to step 102, if die current bill is expected to have die desired denomination, i.e., the preceding bill had die desired denomination, the subroutine branches to step 116 where it is determined whether the current bill indeed has die desired denomination. If die current does have die desired denomination, its value is added to die running total (step 106) and d e subroutine ended (step 108). If at step 116 die current bill does not have die desired denomination, die expecting die desired denomination flag bit is reset (step 118), a denomination change message is displayed (step 112), and a flag is set causing the discriminator to halt operation with the current bill being the last bill deposited in die output receptacle (step 114). The value of the current bill is added to die total (step 106) and the subroutine is ended (step 108). For example, assume the desired off-sort denomination is selected to be $20 bills and a stack of bills having die following denominations is inserted into die input receptacle of a discriminator possessing an embodiment of the sorting operating mode according to the present invention: $1, $1, $5, $5, $1, $20, $20, $20, $20, $5, $5, $20, $20, $20. When the stack is placed in die input receptacle or hopper, the discriminating device may automatically start processing the bills or alternatively may require the selection of a start key. The currency discriminator processes the first six bills, discriminates their denomination, totals dieir values, and halts with die sixtii bill, i.e., the first $20 bill, being the last bill in the output receptacle. Depending on die setup of die discriminator, die discriminator may halt after one or more bills upstream of the sixth bill are scanned but before tiiey are output to the output receptacle. The operator then removes all six bills and separates die first five bills into one pile, e.g. , pile A, and the sixth bill, namely, the $20 bill, into another pile, e.g., pile B. Depending on d e setup of die currency discriminator, die discriminating device may continue to process me remaining bills automatically when the stack of six bills is removed or may continue processing the remaining bills when a continue element is selected. The discriminator then processes the next four bills, discriminates their denomination, adds their values to the running total, and halts witii the tenth bill, i.e., the $5 bill, being the last bill output to the output receptacle. The operator may then remove all the bills from the output receptacle, placing the three $20 bills in pile B and die last $5 bill in pile A. The discriminator then processes the next two remaining bills, discriminates their denomination, adds their values to the running total, and halts widi die twelfth bill, i.e., the $20 bill, being the last bill output to the output receptacle. The operation then continues to proceed in die manner described above. In an alternative embodiment, instead of halting the device widi die flagged bill being die last bill output to the output receptacle, die device may halt witii the flagged bill being at an identifiable location, e.g. , die second to last bill output to die output receptacle, and die display may indicate die location of die flagged bill, e.g. , "denomination changed witii second to die last bill in the output bin. " Suspect Mode In addition to die above modes, a suspect mode may be activated in connection witii these modes whereby one or more authentication tests may be performed on the bills in a stack. When a bill fails an authentication test, the discriminator will stop with the failing or suspect bill being the last bill transported to die output receptacle. The suspect bill then may be removed from the output receptacle and set aside. Likewise, one or more of the above described modes may be activated at die same time. For example, the face mode and the forward/reverse orientation mode may be activated at die same time. In such a case, bills that are either reverse-faced or opposite forward/reverse oriented will be flagged. According to one embodiment, when a bill is flagged, for example, by stopping the transport motor with the flagged bill being die last bill deposited in die output receptacle, d e discriminating device indicates to die operator why the bill was flagged. This indication may be accomplished by, for example, lighting an appropriate light, generating an appropriate sound, and/or displaying an appropriate message in the display section 63 (Fig. 17). Such indication might include, for example, "no call", "stranger", "failed magnetic test", "failed UV test", "no security thread", etc. Means for entering the value of no call bills were discussed above in connection with Fig. 17 and die operating modes discussed above. Now several additional means will be discussed in connection witii FIGs. 19-24 Fig. 19 is a front view of a control panel 2302 similar to that of Fig. 17. The control panel 2302 comprises a display area 2304, several denomination selection elements 2306a-g in the form of keys, left and right scroll keys 2308a-b, an accept selection element 2310, and a continuation selection element 2312. Each denomination selection element 2306a-g has a prompting means associated tiierewith. In Fig. 19, the prompting means are in the form of small lights or lamps 2314a-g such as LEDs. In Fig. 19, the light 2314d associated widi die $10 denomination key 2306d is illuminated so as to prompt the operator that a denomination of $10 is being suggested. Alternatively, instead of die lamps 2314a-g being separate from the denomination keys 2306a-g, the denomination keys could be in die form of illuminable keys whereby one of the keys 2306a-g would light up to suggest its corresponding denomination to the operator. In place of, or in addition to, die illuminable lights 2314a-g or keys, the display area 2304 may contain a message to prompt or suggest a denomination to the operator. In Fig. 19, the display area 2304 contains die message "$10?" to suggest the denomination of $10. In the embodiment of Fig. 17, the display area 63 may be used to suggest a denomination to the operator without the need of illuminable lights and keys. The control panel 2402 of Fig. 20 is similar to the control panel 2302 of Fig. 19; however, the denomination selection elements 2406a-g, scroll keys 2408a-b, accept key 2410, and continuation key 2412 are displayed keys in a touch-screen environment. To select any given key, die operator touches the screen in the area of the key to be selected. The operation of a touch screen is described in more detail in connection with Fig. 25. The discriminator may contain prompting means to suggest a denomination to me operator. For example, an appropriate message may be displayed in a display area 2404. Alternatively, or additionally, die prompting means may include means for highlighting one of the denomination selection elements 2406a-g. For example, the appearance of one of the denomination selection elements may be altered such as by making it lighter or darker dian the remaining denomination selection elements or reversing d e video display (e.g., making light portions dark and making the dark portions light or swapping the background and foreground colors). Alternatively, a designated denomination selection element may be highlighted by surrounding it widi a box, such as box 2414 surrounding die $10 key 2406d. Anodier embodiment of a control panel 2502 is depicted in Fig. 21. The control panel 2502 has several denomination indicating elements 2506a-g in the form of menu list 2505, scroll keys 2508a-b, an accept selection element 2510, and a continuation selection element 2512. The various selection elements may be, for example, physical keys or displayed keys in a touch screen environment. For example, die menu list 2505 may be displayed in a non-touch screen activated display area while the scroll keys 2508a-b, accept key 2510, and continuation key 2512 may be physical keys or displayed touch screen keys. In such an environment a user may accept a denominational selection by pressing the accept key 2510 when the desired denomination indicating element is highlighted and may use the scroll keys 2508a-b to vary the denomination indicating element that is highlighted. Alternatively, the denomination indicating elements 2506a-g may themselves be selection elements such as by being displayed touch screen active keys. In such an embodiment a given denomination element may be made to be highlighted and/or selected by touching die screen in the area of one of the denomination selection elements 2506a-g. The touching of die screen in d e area of one of die denomination selection elements may simply cause the associated denomination selection element to become highlighted requiring the touching and/or pressing of the accept key 2510 or alternatively may constitute acceptance of the associated denomination selection element without requiring the separate selection of the accept key 2510. The discriminator may contain prompting means to suggest a denomination to the operator. For example, an appropriate message may be displayed in a display area 2504. Alternatively, or additionally, die prompting means may include means for highlighting one of the denomination indicating elements 2506a-g. For example, the appearance of one of the denomination indicating elements may be altered such as by making it lighter or darker dian the remaining denomination indicating elements or by reversing the video display (e.g., making light portions dark and making the dark portions light or swapping die background and foreground colors). In Fig. 21, die hash marks are used to symbolize the alternating of d e display of die $10 denomination indicating element 2506d relative to the other denomination indicating elements such as by using a reverse video display. Control panel 2602 of Fig. 22 is similar to control panel 2502 of Fig. 21; however, the control panel 2602 does not have a separate display area. Additionally, die order of the denomination indicating elements 2606a-g of menu list 2605 is varied relative to those of menu list 2505. The order of die denomination selection element may be user-defined (i.e., die operator may preset the order in which the denominations should be listed) or may be determined by die discriminator and be, for example, based on die historical occurrence of no calls of each denomination, based on die denomination of die most recently detected no call, based on calculated correlation values for a given no call bill, or perhaps based on random selection. Such criteria will be described in more detail below. The control panel 2702 of FIGs. 23a and 23b comprises a display area 2704, an accept key 2710, a next or odier denomination key 2711, and a continuation key 2712. Alternatively, the accept key may be designated a "YES" key while die odier denomination key may be designated a "NO" key. These keys may be physical keys or displayed keys. The discriminator prompts or suggest a denomination by displaying an appropriate message in die display area 2704. If the operator wishes to accept this denomination suggestion, the accept key 2710 may be selected. If other the operator wishes to select a different denomination, the other denomination key 2711 may be selected. If in die example given in FIG. 23a d e operator wishes to select a denomination odier than the $5 prompted in die display area 2704, the other denomination key 2711 may be selected which results in prompting of a different denomination, e.g., $2 as shown in FIG. 23b. The "OTHER DENOM" key 2711 may be repeatedly selected to scroll through the different denominations. The control panel 2802 of Fig. 24 is similar to that of FIGs. 23a-b and additionally comprises scroll keys 2808a-b. These scroll keys 2808a-b may be provided in addition to or in place of d e odier denomination key 2811. The order in which denominations are suggested to an operator, for example, in FIGs. 23 and 24, may be based on a variety of criteria as will be discussed below such as user-defined criteria or order, historical information, previous bill denomination, correlation values, or previous no call information. Now several embodiments of the operation of discriminators embodying control panels such as tiiose of FIGs. 17 and 19-24 will be discussed. In particular, several methods for reconciling die value of no call bills will be discussed in connection witii these control panels. As discussed above, for example, in connection with the several previously described operating modes, when a discriminator encounters a no call bill, that is, when a discriminator is unable to determine or call the denomination of a bill, any counters keeping track of die number or value of each denomination of bills or of die total value of the bills processed will not include die no call bill. Traditionally, any no calls bills had to be set aside and manually counted by hand witii the operator being required to add their values to the totals provided by die discriminator. As discussed above, this can lead to errors and reduced efficiency. To counter this problem, according to an embodiment of die present invention, means are provided for incorporating the value of no call bills. In single pocket discriminators, reconciliation may be accomplished on-tiie-fly with the discriminator suspending operation when each no call is encountered, prompting the operator to enter the value of the no call, and d en resuming operation. In multi- output pocket discriminators, no call bills may be reconciled eitiier on-the-fly or after the completion of processing all the bills placed in the input hopper or after completion of processing some other designated batch of bills. Under die first approach, the operation of the discriminator is suspended when each no call bill is detected witii or widiout die no call bill being routed to a special location. The operator is then prompted to enter the value of the no call where upon the discriminator resumes operation. Based on die value indicated by die operator, appropriate counters are augmented. Under die second approach, any no call bills are routed to a special location while the discriminator continues processing subsequent bills. When all the bills have been processed, die operator is prompted to reconcile the values of any intervening no call bills. For example, assume a stack of fifty bills is placed in die input hopper and processed with four no calls being routed to a separate output receptacle from the receptacle or receptacles into which the bills whose denominations have been determined. After all fifty bills have been processed, d e operation of die transport mechanism is halted and the operator is prompted to reconcile die value of die four no call bills. The methods for reconciling these four no calls will be discussed below after describing several denomination indicating and/or prompting means and methods. Alternatively, instead of waiting until all the bills in the stack have been processed, die discriminator may prompt the operator to reconcile the value of any no call bills while the remaining bills are still being processed. When die operator indicates the denominations of die no call bills, appropriate counters are augmented to reflect the value of the no call bills. Several embodiments of means for permitting the operator to indicate die value of a flagged bill such as a no call and/or for prompting the operator as to the value of a flagged bill such as a no call will no w be discussed. A first method was discussed above in connection with several operating modes and in connection with Fig. 17. According to one embodiment, the control panel of Fig. 17 comprises denomination indicating means in the form of the denomination selection elements 64a-g for permitting the operator to indicate die denomination of a bill but does not additionally comprise means for prompting the operator as to the denomination of a particular bill. Under this method, the operator examines a no call bill. If the bill is acceptable, the operator selects the denomination selection element associated witii the denomination of the no call bill and die appropriate counters are augmented to reflect the value of the no call bill. For example, if the operator determines a no call bill is an acceptable $10 bill, die operator may press the $10 selection element 64c of Fig. 17. If the operation of the discriminator had been suspended, the selection of a denomination selection causes the operation of the discriminator to resume. In a on- the-fly reconciliating machine (i.e., one that suspends operation upon detection of each no call bill), if die operator determines that a particular no call bill is unacceptable, a continuation selection element may be selected to cause die discriminator to resume operation without negatively affecting the status of any counters. Under this approach, the denomination selection elements provide die operator widi means for indicating d e value of a no call bill. In FIGs. 19-24, additional examples of means for indicating die value of no call bills are provided. For example, in FIGs. 19-22, according to one embodiment, a denomination may be indicated in a similar manner by pressing one of the denomination selection elements. Alternatively, or additionally, a denomination may be indicated by selecting one of die denomination selection elements and selecting an accept key. Anodier example of a method of indicating a particular denomination selection element would be by utilizing one or more scroll keys. The selection of a denomination selection element may be indicated by, for example, the lights 2314 of Fig. 19, or by highlighting a particular selection element as in FIGs. 20-22. Alternatively a displayed message, as in FIGs. 19-21, 23, and 24, may be used to indicate which denomination is currently selected. The scroll keys could be used to alter which denomination is presently selected, for example, by altering which light 2314 is illuminated, which selection element is highlighted, or which denomination appears in die displayed message. Selection of an accept key while a particular denomination is selected may be used to indicate die selected denomination to the discriminator. In addition to means for permitting the operator to indicate die denomination of one or more no calls, a discriminator may be provided widi one or more means of prompting the operator as to the denomination of a no call bill. These means can be the means used to indicate which denomination is currently selected, e.g., die lights 2314 of Fig. 19, die highlighting of FIGs. 20-22, and/or die displayed message of FIGs. 19-21, 23, and 24. Several methods diat may be employed in prompting the operator to enter the value of one or more no call bills will now be discussed. A discriminator containing means for prompting an operator as to the value of a no call bill may base its selection of the denomination to be prompted to die operator on a variety of criteria. According to one embodiment, default denomination or sequence of denominations may be employed to prompt a denomination to an operator. For example, the discriminator may begin by prompting the lowest denomination, e.g., $1. Alternatively, the operator may begin by prompting the operator with the first denomination in a pre-defined sequence or on a menu list. The order of die denominations in die sequence or on the menu list may be a default order, e.g., increasing or decreasing denominational order, user-defined order, manufacturer-defined order. According to anodier embodiment, a denomination to be prompted to die operator is determined on a random basis. The discriminator simply randomly or pseudo-randomly chooses one of a plurality of denominations and suggests this denomination to the operator. The denomination prompted to an operator may remain the same for all no call bills or alternatively, a new randomly selected denomination may be chosen for each no call encountered. If die operator agrees that a given no call bill is of the denomination suggested by die prompting means and finds die particular no call bill to be acceptable, die operator may simply choose the accept element or the corresponding denomination selection element depending on die embodiment of the control panel employed. If die operator finds a particular bill to be acceptable but does not have die suggested denomination, the operator may alter the denomination that is selected by, for example, altering the displayed suggested denomination by using the scroll keys, scrolling among the plurality of denomination selection and/or indicating elements, or directly selecting the appropriate denomination by pressing or touching the appropriate denomination selection element. If the operator finds tiiat a no call bill is not acceptable, the operator may simply select a continuation key. According to anodier embodiment, a denomination to be prompted to die operator is determined on die basis of die denomination of the last bill that was identified by the discriminator. For example, suppose the tenth bill in a stack was determined by die discriminator to be a $10, the eleventh bill was a no call and indicated by die operator to be a $5 bill, and die twelfth was a no call bill. According to this embodiment, the discriminator would suggest to die operator that die twelfth bill is a $10 bill. The operator may accept this suggestion or alter the suggested denomination as described above. According to anodier embodiment, a denomination to be prompted to the operator is determined on the basis of the denomination of me last no call bill as indicated by die operator. For example, suppose the tenth bill was a no call and indicated by die operator to be a $5 bill, die eleventh bill in a stack was determined by the discriminator to be a $10, and die twelfth was a no call bill. According to tiiis embodiment, the discriminator would suggest to die operator d at die twelfth bill is a $5 bill. The operator may accept this suggestion or alter the suggested denomination as described above. According to anodier embodiment, a denomination to be prompted to die operator is determined on die basis of die denomination of the immediately preceding bill, regardless of whether the denomination of that bill was determined by die discriminator or was indicated by die operator. For example, suppose the tenth bill in a stack was determined by die discriminator to be a $10, me eleventh bill was a no call and indicated by die operator to be a $5 bill, and die twelfth was also a no call bill. According to tiiis embodiment, the discriminator would suggest to die operator that the twelfth bill is a $5 bill. The operator may accept this suggestion or alter the suggested denomination as described above. According to anodier embodiment, a denomination to be prompted to die operator is determined on die basis of historical information concerning no call bills such as statistical information regarding previous no call bills. For example, suppose that for a given discriminator 180 no calls had been encountered since the discriminator was placed in service. According to tiiis embodiment, information regarding tiiese no calls is stored in memory. Assume tiiat of these 180 no call bills, 100 were indicated by die operator to be $5s, 50 were $10s, and die remaining 30 were $20s. According to this embodiment, the discriminator would suggest to tiie operator that a no call bill was a $5. The operator may accept this suggestion or alter the suggested denomination as described above. Variations on die data which constitute the historical basis may be made. For example, die historical basis according to this embodiment may be all no calls encountered since a given machine was place in service as in the above example, the last predetermined number of no calls detected, e.g., die last 100 no calls detected, or the last predetermined number of bills processed, e.g., die no calls encountered in die last 1000 bills processed. Alternatively, the historical basis may be set by the manufacturer based on historical data retrieved from a number of discriminators. According to anodier embodiment, a denomination to be prompted to die operator is determined on die basis of a comparison of information retrieved from a given no call bill and master information associated witii genuine bills. For example, in some discriminators, the denomination of a bill is determined by scanning die bill, generating a scanned pattem from information retrieved via die scanning step, and comparing the scanned pattem witii one or more master patterns associated widi one or more genuine bills associated witii one or more denominations. If die scanned pattem sufficiently matches one of the master patterns, the denomination of the bill is called or determined to be die denomination associated witii the best matching master pattem. However, in some discriminators, a scanned pattem must meet some threshold degree of matching or correlation before the denomination of a bill will be called. In such discriminators, bills whose scanned pattem does not sufficiently match one of the master patterns are not called, i.e., they are no calls. According to die present embodiment, the discriminator would suggest to die operator tiiat a no call had die denomination associated witii the master pattem that most closely matched its scanned pattem even though that match was insufficient to call the denomination of the bill without the concurrence of the operator. The operator may accept this suggestion or alter tiie suggested denomination as described above. For example, in a discriminator similar to tiiat described in U.S. Pat. No. 5,295,196, the discriminator may prompt the operator with the denomination associated with the master pattem that has the highest correlation with the scanned pattem associated witii the given no call bill. Additional examples may be made with reference to FIGs. 3 and 4a-c. For example, with respect to Fig. 3, if the highest correlation for a bill is below 800, the bill is a no call bill. In such a case, assume the highest correlation is 790 and this correlation is associated widi a $1 bill. When tiiis no call bill is to be reconciled, the discriminator would suggest to the operator that die no call was a $1 bill. According to anodier embodiment, a denomination to be prompted to the operator is determined on die basis of preset criteria established by die manufacturer. For example, in Fig. 21, the denomination indicating elements are arranged in increasing denominational order. The discriminator may be designed to default so that a given one of these denomination selection elements is initially highlighted when no call bills are to be reconciled. For example, for each no call the $10 element 2506d may imtially be selected. Alternatively, the discriminator may be designed to default to the first denomination selection element listed, e.g., die $1 denomination element 2506a. According to anodier embodiment, a denomination to be prompted to die operator is determined on die basis of user-defined criteria set by the operator of a discriminator. For example, in Fig. 21, the operator may designate die discriminator to default so that a given one of the denomination indicating elements is initially highlighted when no call bills are to be reconciled. For example, for each no call the operator may designate tiiat the $10 element 2506d is to be initially selected. The operator may be permitted to set the default no call denomination, for example, in a set up mode entered into before bills in a stack are processed. In addition to die ways discussed above whereby an initial denomination is prompted to die operator in connection widi die reconciling a no call bill, according to odier embodiments one or more alternate denominations are may also be suggested. For example, according to die method whereby die initial bill is suggested to die operator based on d e denomination associated widi a master pattem having the highest correlation relative to a scanned pattem, if die operator rejects die initial suggestion, die discriminator may be designed to then suggest an alternate denomination based on die master pattem associated widi a genuine bill of a different denomination having the next highest correlation value. If the operator rejects the second suggestion, die discriminator may be designed to then suggest a second alternate denomination based on die master pattem associated with a genuine bill of a different denomination having die next highest correlation value, and so on. For example, suppose the highest correlation was associated witii a $1, the second highest correlation was associated witii $10, and die tiiird highest correlation was associated witii $50. According to tiiis embodiment, the discriminator would imtially suggest that the no call was a $1. If the operator determined the no call was not a $1, the discriminator would then suggest diat die no call was a $10. If the operator determined die no call was not a $10, die discriminator would d en suggest that the no call was a $50. For example, according to die embodiment of FIGs. 23a- b, die discriminator would first ask whether d e no call was a $1 by displaying die message "$1?" in the display area 2704. If die no call was a $1, die operator would depress die accept or yes key 2710. If die no call was not a $1 bill, die operator would depress die other denomination or no key 2711, in which case, die display area would display die message "$10?" and so on. Alternatively, die denomination selection elements may be arranged so that their relative order is based on die correlation results. For example, taking the menu list 2605 of Fig. 22, the denomination elements may be ordered in the order of decreasing correlation values, e.g., according to die previous example with the $1 denomination element being listed first, die $10 denomination element being listed second, die $50 denomination element being listed tiiird and so on. Alternatively, d e denomination elements may be listed in the reverse order. According to another embodiment, the denomination element associated witii the highest correlation may be listed in d e middle of die list surrounded by die denomination elements associated witii the second and tiiird highest correlations, and so on. For the above example, the $1 element 2606a would be listed in the middle of d e menu list 2605 surrounded by die $10 element 2606d on one side and die $50 element 2606f on the other side. Likewise the order in which denominations are suggested to die operator and/or arranged on die control panel may be based on other criteria such as those described above, such as die prior bill information (e.g., last bill, last no call, last call denomination), historical information, user-defined order, manufacturer-defined order, and random order. For example, using the historical data example given above based on 180 no calls (100 $5 no calls, 50 $10 no calls, and 30 $20 no calls), die order tiiat denominations are suggested to die operator may be first $5, then $10, and dien $20. Alternatively, using the last bill information and assuming the following sequence of bills ($2, $5, $5, $5, $20, $10, no call indicated to be a $50, no call); die discriminator would suggest denominations for the last no call in the following order: $50, $10, $20, $5, $2. Likewise die order in which the denominations are arranged on a control panel such as in FIGs. 22 and 20 may be determined based on such information, for example, according to die orders described above in connection with using correlation values. For example, the denominations may be listed in die prompting order suggested above (e.g. , $5, $10, $20 in the historical information example and $50, $10, $20, $5, $2 in the last bill example). Alternatively they may be listed in the reverse order. Alternatively, tiiey may be arranged with the first suggested denomination being in ti e center of the list and being initially highlighted or selected. This first suggested denomination may be surrounded by die second and tiiird suggested denominations which are in mm surrounded by die fourth and fifth suggested denomination, and so on. A default sequence may be used to provide die order for any remaining denominations which are not dictated by a particular prompting criteria in a given situation. In the above examples, the denominations might be arranged on a menu list in the following orders: $2, $1, $10, $5, $20, $50, $100 for the historical information example and $1, $5, $10, $50, $20, $2, $100. In general, an example of a listing order according to tiiis approach could be from top to bottom: 6th priority or suggested denomination, 4th, 2nd, 1st, 3rd, 5th, and 7th. Embodiments arranging the respective order in which denominations are suggested to tiie operator and/or displayed on the control panel will likely aid die operator by reducing die projected number of times the operator will need to hit one of the scroll keys and/or "OTHER DENOM" or "NO" key. Now several methods will be described in connection reconciliation of no calls in multi-output pocket machines after all bills in a stack have been processed. Recalling a previous example in which four no call bills were separated out from a stack of fifty bills and die machine halted after processing all fifty bills, die discriminator tiien prompts the operator to reconcile the value of the four no call bills. For example, assume the no call bills corresponded to die 5tiι, 20tiι, 30tiι, and 31st bills in the stack and were $2, $50, $10, and $2 bills respectively. The degree of intelligence employed by the discriminator in prompting the operator to reconcile the value of the no call bills may vary depending on die particular embodiment employed. According to one embodiment the operator may depress or select the denomination selection elements corresponding die denominations of the no call bills without any prompting from die discriminator as to their respective denominations. For example, using the control panel of Fig. 17, the operator would depress die $2 selection element 64g twice, the $10 selection element 64c once, and the $50 selection element 64e once. The discriminator may or may not inform the operator that four no call bills must be reconciled and may or may not limit the operator to entering four denominations. Likewise, in odier embodiments, me operator may use the scroll keys to cause the desired denomination to become selected and then depress die accept key. Alternatively, a numerical keypad may be provided for permitting the operator to indicate die number of bills of each denomination that have not been called. For example, the above example, the operator could use die scroll keys so that the $2 denomination was selected, tiien press "2" on the keypad for die number of $2 no calls in the batch, and tiien press an enter or accept key. Then the operator could use die scroll keys so diat die $10 denomination was selected, dien press "1" on the keypad for the number of $10 no calls in the batch, and tiien press an enter or accept key and so on. The keypad may comprise, for example, keys or selection elements associated witii the digits 0-9. Alternatively, die discriminator may prompt the operator as to the denomination of each no call bill, for example, by employing one of d e prompting methods discussed above, e.g., default, random, user-defined criteria, manufacturer defined criteria, prior bill information (last bill, last no call, last called denomination), historical information, scanned and master comparison information (e.g., highest correlation). For example, the discriminator may serially interrogate the examiner as to the denomination of each no call, for example, the display may initially query "Is 1st no call a $2?". Depending on the embodiment of the control panel being used, die operator could dien select "ACCEPT" or "YES" or select the $2 denomination selection element, select "OTHER DENOM" or "NO" or use the scroll keys or select the appropriate denomination selection element, or if the operator finds die first bill unacceptable, die operator may put the first no call bill aside and select "CONT". The discriminator may then query the operator as to the denomination of the second no call bill, and so on. The denomination prompted to die operator would depend on die prompting criteria employed. For example, suppose the prompting criteria was the denomination of the preceding bill and further suppose that in the four no call example given above that the first bill was a $2, the 2nd bill was a $10, die 3rd bill was a $1, the 4th bill was a $1, the 19th bill was a $50, the 29th bill was a $10, and as stated above, the 30th bill was a $10. The discriminator would dien prompt the operator as to whether the first no call was a $1. Since the first no call is a $2, the operator would choose "NO", "OTHER DENOM", scroll, or hit die $2 selection element depending on die embodiment be used. If die "NO" or "OTHER DENOM" key were pressed, the discriminator would review die preceding bills in reverse order and suggest die first denomination encountered tiiat had not already been suggested, in this case a $10. If die "NO" or "OTHER DENOM" key were pressed again, the discriminator would tiien suggest a $2. A predetermined default sequence may be utilized when prior bill information does not contain the desired denomination. Once the operator indicates tiiat the first no call is a $2, the discriminator would dien prompt the operator as to whether the second no call was a $50. Since the second no call was indeed a $50 die operator would choose "ACCEPT", "YES", or select the $50 denomination selection element depending on d e embodiment chosen. The discriminator would dien suggest tiiat the third no call was a $10 and die operator would similarly indicate acceptance of die $10 suggested denomination. Finally, the discriminator would suggest diat die fourth no call was a $10. Since die last no call was a $2, die operator would reject the $10 suggestion and indicate diat die fourth no call bill was a $2 as described above. The operation of the discriminator using a different prompting criteria would proceed in a similar manner and as described above witii respect to each of the described prompting methods. While discussed above widi respect to no calls, die above embodiments could also be employed in connection with odier types of flagged bills such as reverse-faced bills, reverse forward/reverse oriented bills, unfit bills, suspect bills, etc. Referring now to Fig. 25, the touch screen I/O device 2956 includes a touch screen 2960 mounted over a graphics display 2961. In one embodiment, the display 2961 is a liquid crystal display (LCD) witii backlighting. The display may have, for example, 128 vertical pixels and 256 horizontal pixels. The display 2961 contains a built-in character generator which permits the display 2961 to display text and numbers having font and size pre-defined by die manufacturer of die display. Moreover, a controller such as a CPU is programmed to permit the loading and display of custom fonts and shapes (e.g., key outlines) on the display 2961. The display 2961 is commercially available as Part No. GMF24012EBTW from Stanley Electric Company, Ltd., Equipment Export Section, of Tokyo, Japan. The touch screen 2960 may be an X-Y matrix touch screen forming a matrix of touch responsive points. The touch screen 2960 includes two closely spaced but normally separated layers of optical grade polyester film each having a set of parallel transparent conductors. The sets of conductors in the two spaced polyester sheets are oriented at right angles to each otiier so when superimposed tiiey form a grid. Along die outside edge of each polyester layer is a bus which interconnects die conductors supported on diat layer. In tiiis manner, electrical signals from the conductors are transmitted to die controller. When pressure from a finger or stylus is applied to die upper polyester layer, die set of conductors mounted to die upper layer is deflected downward into contact witii the set of conductors mounted to die lower polyester layer. The contact between these sets of conductors acts as a mechanical closure of a switch element to complete an electrical circuit which is detected by die conttoller tiirough the respective buses at the edges of die two polyester layers, tiiereby providing a means for detecting die X and Y coordinates of die switch closure. A matrix touch screen 2960 of the above type is commercially available from Dynapro Thin Film Products, Inc. of Milwaukee, Wisconsin. As illustrated in Fig. 25, the touch screen 2960 forms a matrix of ninety-six optically transparent switch elements having six columns and sixteen rows. The controller is programmed to divide die switch elements in each column into groups of three to form five switches in each column. Acmation of any one of the three switch elements forming a switch actuates the switch. The uppermost switch element in each column remains on its own and is unused. Altiiough the touch screen 2960 uses an X-Y matrix of optically transparent switches to detect die location of a touch, alternative types of touch screens may be substituted for the touch screen 2960. These alternative touch screens use such well- known techniques as crossed beams of infrared light, acoustic surface waves, capacitance sensing, and resistive membranes to detect die location of a touch. The structure and operation of the alternative touch screens are described and illustrated, for example, in U.S. Patent Nos. 5,317,140, 5,297,030, 5,231,381, 5,198,976, 5,184,115, 5,105,186, 4,931,782, 4,928,094, 4,851,616, 4,811,004, 4,806,709, and 4,782,328, which are incorporated herein by reference. Referring now to FIGs. 26a-26c, there is shown a side view of one embodiment of a document authenticating system according to die present invention, a top view of the embodiment of FIG. 26a along me direction 26b, and a top view of d e embodiment of FIG. 26a along the direction 26c, respectively. An ultraviolet ("UV") light source 2102 illuminates a document 2104. Depending upon die characteristics of the document, ultraviolet light may be reflected off die document and/or fluorescent light may be emitted from the document. A detection system 2106 is positioned so as to receive any light reflected or emitted toward it but not to receive any UV light directly from the light source 2102. The detection system 2106 comprises a UV sensor 2108, a fluorescence sensor 2110, filters, and a plastic housing. The light source 2102 and the detection system 2106 are botii mounted to a printed circuit board 2112. The document 2104 is transported in die direction indicated by arrow A by a transport system (not shown). The document is transported over a transport plate 2114 which has a rectangular opening 2116 in it to permit passage of light to and from me document. In one embodiment of the present invention, the rectangular opening 2116 is 1.375 inches (3.493 cm) by 0.375 inches (0.953 cm). To minimize dust accumulation onto the light source 2102 and die detection system 2106 and to prevent document jams, the opening 2116 is covered with a transparent UV transmitting acrylic window 2118. To further reduce dust accumulation, the UV light source 2102 and die detection system 2106 are completely enclosed within a housing (not shown) comprising the transport plate 2114. Referring now to Fig. 27, there is shown a functional block diagram illustrating one embodiment of a document autiienticating system according to die present invention. Fig. 27 shows an UV sensor 2202, a fluorescence sensor 2204, and filters 2206, 2208 of a detection system such as the detection system 2106 of FIGs. 26a-c. Light from the document passes through the filters 2206, 2208 before striking the sensors 2202, 2204, respectively. An ultraviolet filter 2206 filters out visible light and permits UV light to be transmitted and hence to strike UV sensor 2202. Similarly, a visible light filter 2208 filters out UV light and permits visible light to be transmitted and hence to strike fluorescence sensor 2204. Accordingly, UV light, which has a wavelengtii below 400 nm, is prevented from striking the fluorescence sensor 2204 and visible light, which has a wavelengtii greater than 400 nm, is prevented from striking die UV sensor 2202. In one embodiment die UV filter 2206 transmits light having a wavelengtii between about 260 nm and about 380 nm and has a peak transmittance at 360 nm. In one embodiment, the visible light filter 2208 is a blue filter and preferably transmits light having a wavelength between about 415 nm and about 620 nm and has a peak transmittance at 450 nm. The above preferred blue filter comprises a combination of a blue component filter and a yellow component filter. The blue component filter transmits light having a wavelength between about 320 nm and about 620 nm and has a peak transmittance at 450 nm. The yellow component filter transmits light having a wavelength between about 415 nm and about 2800 nm. Examples of suitable filters are UG1 (UV filter), BG23 (blue bandpass filter), and GG420 (yellow longpass filter), all manufactured by Schott. In one embodiment the filters are about 8 mm in diameter and about 1.5 mm thick. The UV sensor 2202 outputs an analog signal proportional to the amount of light incident tiiereon and tiiis signal is amplified by amplifier 2210 and fed to a microcontroller 2212. Similarly, the fluorescence sensor 2204 outputs an analog signal proportional to the amount of light incident tiiereon and tiiis signal is amplified by amplifier 2214 and fed to a microcontroller 2212. Analog-to-digital converters 2216 witiiin the microcontroller 2212 convert the signals from the amplifiers 2210, 2214 to digital and tiiese digital signals are processed by die software of the microcontroller 2212. The UV sensor 2202 may be, for example, an ultraviolet enhanced photodiode sensitive to light having a wavelength of about 360 nm and die fluorescence sensor 2204 may be a blue enhanced photodiode sensitive to light having a wavelength of about 450 nm. Such photodiodes are available from, for example, Advanced Photonix, Inc., Massachusetts. The microcontroller 2212 may be, for example, a Motorola 68HC16. The exact characteristics of die sensors 2202, 2204 and the filters 2206, 2208 including the wavelength transmittance ranges of the above filters are not as critical to the present invention as the prevention of the fluorescence sensor from generating an output signal in response to ultraviolet light and the ultraviolet sensor from generating an output signal in response to visible light. For example, instead of, or in addition to, filters, a authentication system according to the present invention may employ an ultraviolet sensor which is not responsive to light having a wavelength longer than 400 nm and/or a fluorescence sensor which is not responsive to light having a wavelength shorter than 400 nm. Calibration potentiometers 2218, 2220 permit the gains of amplifiers 2210, 2214 to be adjusted to appropriate levels. Calibration may be performed by positioning a piece of white fluorescent paper on the transport plate 2114 so that it completely covers the rectangular opening 2116 of FIGs. 26a-c. The potentiometers 2218, 2220 may then be adjusted so tiiat the output of the amplifiers 2210, 2214 is 5 volts. Alternatively, calibration may be performed using genuine currency such as a piece of genuine U.S. currency. Potentiometers 2218 and 2220 may be replaced widi electronic potentiometers located, for example, within the microcontroller 2212. Such electronic potentiometers may permit automatic calibration based on die processing of a single genuine document or a plurality of documents as will be described below. The implementation of one embodiment of a document autiienticating system according to die present invention as illustrated in Fig. 27 with respect to the authentication of U.S. currency will now be described. As discussed above, it has been determined tiiat genuine United States currency reflects a high level of ultraviolet light and does not fluoresce under ultraviolet illumination. It has also been determined diat under ultraviolet illumination counterfeit United States currency exhibits one of d e four sets of characteristics listed below: 1) Reflects a low level of ultraviolet light and fluoresces; 2) Reflects a low level of ultraviolet light and does not fluoresce; 3) Reflects a high level of ultraviolet light and fluoresces; 4) Reflects a high level of ultraviolet light and does not fluoresce. Counterfeit bills in categories (1) and (2) may be detected by a currency authenticator employing an ultraviolet light reflection test according to one embodiment of the present invention. Counterfeit bills in category (3) may be detected by a currency autiienticator employing both an ultraviolet reflection test and a fluorescence test according to anodier embodiment of the present invention. Only counterfeits in category (4) are not detected by die autiienticating methods of die present invention. According to one embodiment of the present invention, fluorescence is determined by any signal diat is above die noise floor. Thus, die amplified fluorescent sensor signal 2222 will be approximately 0 volts for genuine U.S. currency and will vary between approximately 0 and 5 volts for counterfeit bills depending upon tiieir fluorescent characteristics. Accordingly, an autiienticating system according to one embodiment of the present invention will reject bills when signal 2222 exceeds approximately 0 volts. According to one embodiment of me present invention, a high level of reflected UV light ("high UV") is indicated when die amplified UV sensor signal 2224 is above a predetermined threshold. The high/low UV tiireshold is a function of lamp intensity and reflectance. Lamp intensity can degrade by as much as 50% over the life of the lamp and can be further attenuated by dust accumulation on the lamp and die sensors. The problem of dust accumulation is mitigated by enclosing me lamp and sensors in a housing as discussed above. An autiienticating system according to one embodiment of me present invention tracks the intensity of the UV light source and readjusts die high/low tiireshold accordingly. The degradation of die UV light source may be compensated for by periodically feeding a genuine bill into the system, sampling the output of the UV sensor, and adjusting die tiireshold accordingly. Alternatively, degradation may be compensated for by periodically sampling the output of the UV sensor when no bill is present in the rectangular opening 2116 of the transport plate 2114. It is noted diat a certain amount of UV light is always reflected off die acrylic window 2118. By periodically sampling d e output of the UV sensor when no bill is present, the system can compensate for light source degradation. Furthermore, such sampling could also be used to indicate to the operator of die system when the ultraviolet light source has burned out or otherwise requires replacement. This may be accomplished, for example, by means of a display reading or an illuminated light emitting diode ("LED"). The amplified ultraviolet sensor signal 2224 will initially vary between 1.0 and 5.0 volts depending upon tiie UV reflectance characteristics of the document being scanned and will slowly drift downward as die light source degrades. In an alternative embodiment to one embodiment wherein the threshold level is adjusted as die light source degrades, die sampling of the UV sensor output may be used to adjust the gain of the amplifier 2210 thereby maintaining the output of the amplifier 2210 at its initial levels. It has been found diat die voltage ratio between counterfeit and genuine U.S. bills varies from a discernable 2-to-l ratio to a non-discernable ratio. According to one embodiment of the present invention a 2-to-l ratio is used to discriminate between genuine and counterfeit bills. For example, if a genuine U.S. bill generates an amplified UV output sensor signal 2224 of 4.0 volts, documents generating an amplified UV output sensor signal 2224 of 2.0 volts or less will be rejected as counterfeit. As described above, tiiis threshold of 2.0 volts may either be lowered as the light source degrades or the gain of the amplifier 2210 may be adjusted so that 2.0 volts remains an appropriate threshold value. According to one embodiment of the present invention, the determination of whether die level of UV reflected off a document is high or low is made by sampling the output of the UV sensor at a number of intervals, averaging the readings, and comparing the average level with the predetermined high/low threshold. Alternatively, a comparison may be made by measuring the amount of UV light reflected at a number of locations on the bill and comparing these measurements with those obtained from genuine bills. Alternatively, the output of one or more UV sensors may be processed to generate one or more patterns of reflected UV light and tiiese patterns may be compared to die patterns generated by genuine bills. Such a pattem generation and comparison technique may be performed by modifying an optical pattem technique such as that disclosed in United States Pat. No. 5,295,196 incorporated herein by reference in its entirety or in United States patent application Serial No. 08/287,882 filed August 9, 1994 for a "Method and Apparatus for Document Identification," incorporated herein by reference in its entirety. In a similar manner, the presence of fluorescence may be performed by sampling the output of the fluorescence sensor at a number of intervals. However, in one embodiment, a bill is rejected as counterfeit U.S. currency if any of die sampled outputs rise above the noise floor. However, the alternative methods discussed above with respect to processing the signal or signals of a UV sensor or sensors may also be employed, especially witii respect to currencies of other countries or other types of documents which may employ as security features certain locations or patterns of fluorescent materials. A currency authenticating system according to die present invention may be provided witii means, such as a display, to indicate to die operator the reasons why a document has been rejected, e.g., messages such as "UV FAILURE" or "FLUORESCENCE FAILURE. " A currency authenticating system according to the present invention may also permit the operator to selectively choose to activate or deactivate eitiier the UV reflection test or the fluorescence test or both. A currency autiienticating system according to die present invention may also be provided widi means for adjusting the sensitivities of the UV reflection and/or fluorescence test, for example, by adjusting the respective thresholds. For example, in the case of U.S. currency, a system according to die present invention may permit the high/low tiireshold to be adjusted, for example, either in absolute voltage terms or in genuine/suspect ratio terms. The UV and fluorescence autiientication test may be incorporated into various document handlers such as currency counters and/or currency denomination discriminators such as that disclosed in connection witii FIGs. 1 and 14-16b and U.S. Patent No. 5,295,196 incorporated herein by reference in its enitirety. In such systems, calibration may be performed by processing a stack of genuine documents. An example of a method of calibrating such a device will now be discussed. As mentioned above, die acrylic window 818 reflects a certain amount of UV light even when no bill is present. The amount of UV light reflected in die absence of bills is measured. A stack of genuine bills may then be processed with the potentiometer 2218 set to some arbitrary value and die resulting UV readings averaged. The difference between the average reading and the reading made in die absence of bills may then be calculated. The potentiometer 2218 may then be adjusted so diat die average reading would be at least 0.7 volts greater dien die no bill reading. It is also desirable to adjust die potentiometer 2218 so that the amplifier 2210 operates around die middle of its operating range. For example, if a reading of 1.0 volt results when no bills are present and an average reading of 3.0 volts results when a stack of genuine bills are processed, die resulting difference is 2.0 volts which is greater than 0.7 volts. However, it is desirable for the amplifier to be operating in the range of about 2.0 to 2.5 volts and preferably at about 2.0 volts. Thus in the above example, the potentiometer 2218 may be used to adjust the gain of die amplifier 2210 so that an average reading of 2.0 volts would result. Where potentiometer 2218 is an electronic potentiometer, the gain of d e amplifier 2210 may be automatically adjusted by die microcontroller 2212. In general, when the average reading is too high die potentiometer is adjusted to lower die resulting values to the center of the operating range of the amplifier and vice versa when the average reading is too low. According to anodier embodiment of the present invention, the operator of a document handling device such as a currency counter or a currency denomination discriminator is provided widi die ability to adjust the sensitivity of a UV reflection test, a fluorescence test, and a magnetic test. For example, a note counter embodying an embodiment of the present invention may provide die operator die ability to set die autiientication tests to a high or a low sensitivity. For example, the note counter may be provided widi a set up mode which enables die operator to adjust die sensitivities for each of the above tests for both the high and die low modes. This may be achieved tiirough appropriate messages being displayed on, for example, display 36 of FIG. 2 and the input of selection choices via an input device such as a keyboard or buttons. In one embodiment, the device permits the operator to adjust die UV test, d e fluorescent test, and die magnetic test in a range of sensitivities 1 - 7, widi 7 being the most sensitive, or to turn each test off. The device permits setting the sensitivity as described above for die three authentication tests for both a low sensitivity (low denomination) mode and a high sensitivity (high denomination) mode. The above setting options are summarized in Table 1. Table 1 Mode UV Test Fluorescent Test Magnetic Test Sensitivity Sensitivity Sensitivity High off, 1-7 off, 1-7 off, 1-7 Low off, 1-7 off, 1-7 off, 1-7 According to an alternate embodiment, die above high low modes are replaced widi denomination modes, for example, one for each of several denominations of currency (e.g., $1, $2, $5, $10, $20, $50 and $100). For each denomination, the sensitivity of die tiiree tests may be adjusted between 1-7 or off. According to one embodiment for operator manually selects eitiier die high or low mode or the appropriate denomination mode based on die values of die notes to be processed. This manual mode selection system may be employed in, for example, either a note counter or a currency denomination discriminator. According to anodier embodiment the document handling system automatically selects either the high or low mode or the appropriate denomination mode based on the values of the notes being processed. This automatic mode selection system may be employed in systems capable of identifying die different values or kinds of documents, for example, a currency denomination discriminator. Accordingly, in die low mode or for low denomination modes (e.g., $1, $2) die tiiree tests may be set to relatively low sensitivities (e.g., UV test set at 2, fluorescent test set at 5, and magnetic test set at 3). Conversely, in the high mode or for high denomination modes (e.g., $50, $100) the three tests may be set to relatively high sensitivities (e.g., UV test set at 5, fluorescent test set at 6, and magnetic test set at 7). In this way, authentication sensitivity may be increased when processing high value notes where the potential harm or risk in not detecting a counterfeit may be greater and may be decreased when processing low value notes where the potential harm or risk in not detecting a counterfeit is lesser and die annoyance of wrongly rejecting genuine notes is greater. Also the UV, fluorescent, and/or magnetic characteristics of genuine notes can vary due to number of factors such wear and tear or whether the note has been washed (e.g., detergents). As a result, die fluorescent detection of genuine U.S. currency, for example, may yield readings of about 0.05 or 0.06 volts. The UV and fluorescent thresholds associated witii each of the seven sensitivity levels may be set, for example, as shown in Table 2. Table 2 Sensitivity UV Test Fluorescent Test Level (Volts) (Volts) 1 0.2 0.7 2 0.3 0.6 3 0.4 0.5 4 0.5 0.3 5 0.55 0.2 6 0.6 0.15 7 0.7 0.1 In performing the UV test according to one embodiment, the no bill reflectance value is subtracted from resulting UV reflectance voltages associated witii the scanning of a particular bill, and tiiis difference is compared against me appropriate threshold value such as those in Table 2 in determining whether to reject a bill. According to one embodiment, the potentiometer 2220 associated witii the fluorescence detector 2204 is calibrated by processing a genuine note or stack of notes, as described above in connection with die calibration of die UV detector, and adjusted so tiiat a reading of near 0 volts (e.g., about 0.1 volt) results. Magnetic calibration may be performed, for example, manually in conjunction with the processing of a genuine bill of known magnetic characteristics and adjusting the magnetic sensor to near the center of its range. Upon a bill failing one or more of the above tests, an appropriate error message may be displayed such as "Suspect Document U~" for failure of the UV reflection test, "Suspect Document -F-" for failure of the fluorescent test, "Suspect Document ~M" for failure of the magnetic test, or some combination thereof when more than one test is failed (e.g., "Suspect Document UF-" for failure of both the UV reflection test and die fluorescent test). While die present invention has been described witii reference to one or more particular embodiments, those skilled in die art will recognize tiiat many changes may be made thereto without departing from the spirit and scope of die present invention. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of die claimed invention, which is set forth in die following claims.

Claims: We claim: 1. A currency counting and discrimination device for receiving a stack of currency bills, rapidly counting and discriminating the bills in the stack, and dien re- stacking the bills comprising: an input receptacle for receiving a stack of currency bills to be discriminated; a discriminating unit for discriminating the denomination of said currency bills; one or more output receptacles for receiving said currency bills after being discriminated by said discriminating unit; a transport mechanism for transporting said currency bills, one at a time, from said input receptacle past a sensor of said discriminating unit and to said one or more output receptacles; one or more counters keeping track of the value of bills discriminated; and means for an operator of said device to indicate the value of any bills whose denomination are not determined by said discriminating unit, said bills whose denomination are not determined by said discriminating unit being no call bills, said means appropriately effecting said one or more counters. 2. The discrimination device of claim 1 further comprising means for prompting an operator of the device as to die denomination of a no call bill. 3. The discrimination device of claim 2 wherein said prompting means initially suggests that die denomination of a no call bill based on a criteria selected from the group consisting of: immediately prior bill information, last no call information; last called bill information, scanned and master data comparison information, user-defined information, manufacturer-defined information, historical information, default information, and random basis. 4. A currency counting and discrimination device for receiving a stack of currency bills, rapidly counting and discriminating the bills in die stack, and tiien re- stacking the bills comprising: an input receptacle for receiving a stack of currency bills to be discriminated; a discriminating unit for discriminating the denomination of said currency bills; one or more output receptacles for receiving said currency bills after being discriminated by said discriminating unit; a transport mechanism for transporting said currency bills, one at a time, from said input receptacle past a sensor of said discriminating unit and to said one or more output receptacles; one or more counters keeping track of the value of bills discriminated; means for flagging bills meeting or failing to meet to predetermined criteria, and means for an operator of said device to indicate die value of any flagged bills, said means appropriately effecting said one or more counters. 5. The discrimination device of claim 4 further comprising means for prompting an operator of the device as to die denomination of a flagged bill. 6. A currency counting and discrimination machine for receiving currency bills in an input receptacle, rapidly counting and discriminating said currency bills, and then discharging said currency bills to an output receptacle, comprising: a sensing device for scanning and counting said currency bills; a controller coupled to said sensing device; a transport mechanism engaging and transporting said currency bills, one at a time, along a transport path from said input receptacle to said output receptacle, a segment of said transport padi being adjacent said sensing device; means for detecting when a currency bill is jammed along said transport patii, said detecting means being coupled to said controller and producing a jam signal upon detection of a jammed currency bill; means coupled to said controller for interrupting the operation of said transport mechanism in response to said jam signal from said detecting means; and means for adjusting a portion of said transport mechanism to release said jammed currency bill in said transport mechanism. 7. The currency counting and discrimination machine of claim 6, further comprising an operator control panel having a forward key and a reverse key coupled to said controller for producing a forward signal and a reverse signal, respectively, said controller instructing said transport mechanism to operate in a forward direction upon receipt of said forward signal and instructing said transport mechamsm to operate in a reverse direction upon receipt of said reverse signal. 8. The currency counting and discrimination machine of claim 6, wherein said adjusting means includes at least one solenoid coupled to said controller, said solenoid displacing said portion of said transport mechanism from an operational position to a retracted position when energized. 9. A sensing mechanism for a currency counting and discrimination machine, said machine for receiving currency bills in an input receptacle, rapidly counting and discriminating said currency bills, and dien discharging said currency bills to an output receptacle, said machine including a transport mechanism for transporting said currency bills from said input receptacle to said output receptacle along a transport patii, said sensing mechanism being adjacent said transport path in an operational position, said sensing mechanism comprising: a sensing device for counting and discriminating said currency bills; a first member on which a portion of said sensing device is mounted and forming a portion of said transport mechanism; and means for adjusting said first member to a retracted position to relieve pressure exerted on a jammed currency bill. 10. A method for clearing a jammed currency bill from a transport patii in a currency counting and discrimination machine, said machine receiving currency bills in an input receptacle, rapidly counting and discriminating said currency bills, and tiien discharging said currency bills to an output receptacle, said machine including a transport mechanism for transporting said currency bills from said input receptacle to said output receptacle along said transport path, said machine further including a sensing device adjacent said transport patii, said method comprising the steps of: detecting said jammed currency bill in said transport patii; interrupting the operation of said transport mechanism; adjusting a portion of said transport mechamsm from an operational position to a retracted position to relieve pressure on said jammed currency bill; activating said transport mechanism to dislodge said jammed currency bill and move said jammed currency bill to said input receptacle or said output receptacle; and re rning said portion of said transport mechanism to said operational position. 11. A currency counting and discrimination machine for receiving currency bills in an input receptacle, rapidly counting and discriminating said currency bills, and dien discharging said currency bills to an output receptacle, comprising: a sensing device for scanning and counting said currency bills; a controller coupled to said sensing device; a transport mechanism engaging and transporting said currency bills, one at a time, along a transport padi from said input receptacle to said output receptacle, a segment of said transport patii being adjacent said sensing device; means for detecting when a currency bill is jammed along said transport patii, said detecting means being coupled to said controller and producing a jam signal upon detection of a jammed currency bill; means coupled to said controller for interrupting the operation of said transport mechanism in response to said jam signal from said detecting means; and means for adjusting a portion of said transport mechanism to relieve pressure exerted on said jammed currency bill by said transport mechanism. 12. A method of off-sorting currency of a specific denomination using a device capable of discriminating the denomination of currency bills comprising the steps of: receiving a stack of bills in an input receptacle; transporting said bills, one at a time, past a denomination discriminating unit to an output receptacle; discriminating the denomination of each bill; determining whether the denomination of a current bill is a specified denomination; and eitiier (1) halting operation of the device when said current bill does have said specified denomination and an immediately preceding bill does not have said specified denomination; (2) halting operation of the device when said current bill does not have said specified denomination and said immediately preceding bill does have said specified denomination; or (3) continuing operation of the device. 13. The method of claim 12 wherein said halting steps are performed so that said current bill is the last bill output to said output receptacle when said device is halted. 14. The method of claim 12 wherein said device has a single output receptacle. 15. A method of off-sorting documents of a specific type using a device capable of discriminating among different types of documents comprising the steps of: receiving a stack of documents in an input receptacle; transporting said documents, one at a time, past a document type discriminating unit to an output receptacle; discriminating the type of each document; determining whether the type of a current document is a specified type; and eitiier (1) halting operation of the device when said current document is of said specified type and an immediately preceding document is not of said specified type; (2) halting operation of the device when said current document is not of said specified type and said immediately preceding document is of said specified type; or (3) continuing operation of the device. 16. A device for off-sorting currency of a specific denomination comprising: an input receptacle for receiving a stack of bills; and a transport mechanism for transporting said bills, one at a time, past a denomination discriminating unit to an output receptacle; wherein said discriminating unit discriminates the denomination of each bill, determines whether a current bill has a specified denomination; and wherein said device eitiier (1) halts operation when said current bill does have said specified denomination and an immediately preceding bill does not have said specified denomination; (2) halts operation when said current bill does not have said specified denomination and said immediately preceding bill does have said specified denomination; or (3) continues operation. 17. The device of claim 16 having a single output receptacle. 18. The device of claim 16 wherein when the operation of said device is halted said current bill is the last bill output to said output receptacle. 19. A device for authenticating documents comprising: an ultraviolet light source for illuminating a document to be tested; an ultraviolet light detector for generating an output signal responsive to ultraviolet light reflected by said document; a signal processor for receiving said ultraviolet detector output signal and determining the authenticity of said document based upon said output signal; said signal processor determining the authenticity of by comparing said output signal to one of a plurality of reference signals; said plurality of reference signals being associated witii various sensitivity settings; and means for selecting said one of a plurality of reference signals. 20. A device for authenticating documents comprising: a sensor for receiving characteristic information from a document, said sensor generating a authentication signal; a signal processor for receiving said authentication signal, said signal processor comparing said autiientication signal to a reference signal and determining the authenticity of said document based on said comparison, said reference signal being set to one of a plurality of settings, said settings being associated wim varying degrees of sensitivity; and means for selecting of said settings whereby the sensitvity of said autiientication device can be varied according to which one of said settings is selected. 21. The device of claim 20 further comprising: a discriminating unit for discriminating the type of a document, said discriminating unit being able to discriminate a plurality of document types; a reference signal associated witii each of said plurality of document types; wherein said signal processor compares said autiientication to the reference signal associated widi die document type which said discriminating unit determines siad document to be; and wherein said means for selecting said settings permits said references signals associated with each of said document types to be set to different settings, whereby the sensitivity of said autiienticating device may vary according to the document types of said document. 22. The device of claim 21 wherein said document is a currency bill and said document types are different denominations of currency bills, each of said denominations having a reference signal associated tiierewith, wherein the settings of said reference signals may be varied by denomination whereby the sensitivity of said authenticating device may vary according to the denomination of said currency bill as determined by said discriminating unit.

Inventors: CSULITS FRANK M, GRAVES BRADFORD T, JONES JOHN E, JONES WILLIAM J, MENNIE DOUGLAS U, MUNRO MARK C, CSULITS, FRANK, M., GRAVES, BRADFORD, T., JONES, JOHN, E., JONES, WILLIAM, J., MENNIE, DOUGLAS, U., MUNRO, MARK, C.
Applicants: CSULITS FRANK M, CUMMINS ALLISON CORP, GRAVES BRADFORD T, JONES JOHN E, JONES WILLIAM J, MENNIE DOUGLAS U, MUNRO MARK C, CSULITS, FRANK, M., CUMMINS-ALLISON CORPORATION, GRAVES, BRADFORD, T., JONES, JOHN, E., JONES, WILLIAM, J., MENNIE, DOUGLAS, U., MUNRO, MARK, C.
Application year: 1995
Main classification: G06K9
IPC codes: B65H3, G06Q20, G07D7, G07D11, G07F7, G07F19