Automatic currency processing system having ticket redemption module

Abstract

An apparatus for currency discrimination comprises first and second stationary scanheads, disposed on opposite sides of a bill transport path, for scanning respective first and second opposing surfaces of a bill traveling along the bill transport path and for producing respective output signals. The bill travels along the transport path in the direction of a predetermined dimension of the bill. A memory stores master characteristic patterns corresponding to associated predetermined surfaces of a plurality of denominations of genuine bills. Sampling circuitry samples the output signals associated with the respective first and second opposing surfaces of the scanned bill. A signal processor is programmed to determine which one of the first and second opposing surfaces corresponds to the associated predetermined surfaces of the plurality of denominations of genuine bills. The processor then correlates the output signal associated with the one of the first and second opposing surfaces corresponding to the associated predetermined surfaces with the master characteristic patterns to identify the denomination of the scanned bill.

Claims

What is claim is:

1. A machine for redeeming items of value from a customer, comprising:

a bill module for receiving bills inputted by said customer, said bill module discriminating between valid and invalid bills;

a ticket verifier for receiving a ticket containing a bar code indicative of a monetary ticket value;

a bill dispenser for dispensing bills to said customer;

a coin dispenser for dispensing coins to said customer; and

a controller coupled to said bill module, said ticket verifier, and said coin and bill dispensers, said controller determining a total inputted value that is the summation of values of said valid bills and said monetary ticket value of said ticket verifier, said controller instructing said coin and bill dispensers to dispense coins and bills having a redeemed value that is related to said total inputted value.

2. The redemption machine of claim 1, wherein said redeemed value is equivalent to said total inputted value.

3. The redemption machine of claim 1, further including a coin module for receiving bulk mixed coins inputted by said customer, said coin module discriminating between valid and invalid coins of said bulk mixed coins and counting said valid coins, said total inputted value determined from said controller including a value of said valid coins.

4. The redemption machine of claim 3, wherein said coin module is receiving tokens.

5. The redemption machine of claim 1, wherein said bill module, said ticket verifier, said coin dispenser, said bill dispenser, and said controller are all integrated into a single housing.

6. The redemption machine of claim 1, wherein said bill module receives a stack of bills of mixed denominations.

7. The redemption machine of claim 1, further including a slot for receiving a card having data stored thereon.

8. The redemption machine of claim 7, wherein said data includes the identification of said customer.

9. The redemption machine of claim 8, wherein said machine is connected to a central accounting system for recording the transaction of said customer.

10. The redemption machine of claim 1, wherein said machine is connected to a central accounting system for recording the transaction of said customer.

11. A method for redeeming items of value from a customer, comprising:

receiving, at a self-service redemption machine, bills inputted by said customer;

discriminating between valid and invalid bills within said machine;

receiving, at said machine, a ticket containing a bar code indicative of a monetary ticket value;

determining a total inputted value that is the summation of a value of said valid bills and said monetary ticket value of said ticket verifier; and

instructing coin and bill dispensers within said machine to dispense coins and bills having a total redeemed value that is related to said total inputted value.

12. The method of claim 11, wherein said receiving said bills includes receiving a stack of bills of mixed denominations.

13. The method of claim 11, wherein said total redeemed value is equal to said total inputted value.

14. The method of claim 11, further including receiving from said customer a card having data stored thereon and reading said data from said card.

15. The method of claim 14, wherein said data includes the identification of said customer.

16. The method of claim 15, further including recording the transaction by said customer in a central accounting system.

17. The method of claim 11, further including recording the transaction by said customer in a central accounting system.

18. A machine for redeeming currency from a customer, comprising:

a coin module for receiving bulk mixed coins inputted by said customer, said coin module discriminating between valid and invalid coins of said bulk mixed coins;

a bill module for receiving bills inputted by said customer, said bill module discriminating between valid and invalid bills;

a ticket verifier for receiving a ticket inputted by said customer, said ticket containing a bar code indicative of a monetary ticket value;

a bill dispenser for dispensing bills to said customer;

a coin dispenser for dispensing coins to said customer;

a slot for receiving a card having data stored thereon;

a connector coupling said machine to an accounting system; and

a controller coupled to said coin module, said bill module, said ticket verifier, said bill dispenser, said coin dispenser and said slot for reading said data from said card, said controller determining a total inputted value from said customer, said controller communicating with said accounting system via said connector to send information from the transaction to said accounting system, said controller instructing said coin and bill dispensers to dispense coins and bills having a redeemed value that is related to said total inputted value.

19. The redemption machine of claim 18, wherein said redeemed value is equivalent to said total inputted value.

20. An automated teller machine for performing transactions with a customer, said machine being connected to an accounting system, comprising:

a dispenser for dispensing money to said customer;

a coin input module for receiving bulk mixed coins inputted by said customer, said coin module discriminating between valid and invalid coins of said bulk mixed coins;

means for determining an inputted value of said valid coins of said bulk mixed coins;

a slot for receiving a card having customer identification data stored thereon;

a connector connecting said machine to said accounting system; and

a controller coupled to said dispenser, said coin input module, and said slot for reading said card, said controller sending instructions via said connector to said accounting system for crediting a personal customer account by an amount related to said inputted value.

Description

FIELD OF THE INVENTION

The present invention relates to currency processing systems such as automatic teller machines and currency redemption machines.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide an improved automatic teller machine ("ATM") or currency redemption machine that is capable of processing cash deposits as well as withdrawals.

Another object of this invention is to provide such machines that are capable of accepting and dispensing coins as well as bills.

A further object of this invention is to provide such machines that automatically evaluate the authenticity, as well as the denomination, of the cash that is deposited, whether in the form of bills or coins.

Still another object of the invention is to provide such machines that are coupled to the cash accounting system of a bank or other financial institution so that the customer's account can be immediately credited with verified cash deposit amounts.

In accordance with the present invention, the foregoing objectives are realized by providing a currency processing machine for receiving and dispensing cash and substantially immediately furnishing an associated cash accounting system with data, including the value of the currency processed, for each transaction. The machine includes a bill dispenser having a bill storage device and controllable transport means for dispensing selected numbers of bills from the storage device, a bill receptacle for receiving stacks of bills to be deposited, and a bill counter and scanner for rapidly removing the bills one at a time from the receptacle and counting the bills while determining the denomination of each bill. The counter and scanner also generates data representing the denomination of each bill, and the number of bills of each denomination, passed through the counter and scanner. A memory receives and stores data representing the number of bills of each denomination passed through the counter and scanner in each transaction, and data representing the total value of the bills passed through the counter and scanner in each transaction. A control system transfers data from the memory to an associated cash accounting system so that the deposits and withdrawals executed at the currency processing machine are entered in the accounting system substantially immediately after the execution of those transactions. The preferred control system checks the genuineness of each bill and coin that is counted, and produces a control signal in response to the detection of a non-genuine bill or coin. The processing of the bill or coin detected to be non-genuine is altered in response to such control signals.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a perspective view of an automatic teller machine embodying the present invention;

FIG. 1b is a diagrammatic side elevation of the machine of FIG. 1a;

FIG. 1c is a more detailed diagrammatic side elevation of the machine of FIG. 1a;

FIG. 1d is a flow chart illustrating the sequential procedure involved in the execution of a transaction in the machine of FIG. 1a;

FIG. 1e is a flow chart illustrating the sequential procedure involved in the execution of a deposit of bills in the machine of FIG. 1a;

FIG. 1f is a flow chart illustrating an alternative sequential procedure involved in the execution of a deposit of bills in the machine of FIG. 1a;

FIG. 2a is a functional block diagram of the currency scanning and counting subassembly in the machine of FIG. 1, including a scanhead arranged on each side of a transport path;

FIG. 2b is a functional block diagram of a currency scanning and counting device that includes a scanhead arranged on a single side of a transport path;

FIG. 2c is a functional block diagram of a currency scanning and counting machine similar to that of FIG. 2b, but adapted to feed and scan bills along their wide dimension;

FIG. 2d is a functional block diagram of a currency scanning and counting device similar to those of FIGS. 2a-2c but including a second type of scanhead for detecting a second characteristic of the currency;

FIG. 3 is a diagrammatic perspective illustration of the successive areas scanned during the traversing movement of a single bill across an optical sensor according to a preferred embodiment of the primary scanhead;

FIGS. 4a and 4b are perspective views of a bill and a preferred area to be optically scanned on the bill;

FIGS. 5a and 5b are diagrammatic side elevation views of the preferred areas to be optically scanned on a bill according to a preferred embodiment of the invention;

FIG. 6a is a perspective view of a bill showing the preferred area of a first surface to be scanned by one of the two scanheads employed in the preferred embodiment of the present invention;

FIG. 6b is another perspective view of the bill in FIG. 6a showing the preferred area of a second surface to be scanned by the other of the scanheads employed in the preferred embodiment of the present invention;

FIG. 6c is a side elevation showing the first surface of a bill scanned by an upper scanhead and the second surface of the bill scanned by a lower scanhead;

FIG. 6d is a side elevation showing the first surface of a bill scanned by a lower scanhead and the second surface of the bill scanned by an upper scanhead;

FIGS. 7a and 7b form a block diagram illustrating a preferred circuit is arrangement for processing and correlating reflectance data according to the optical sensing and counting technique of this invention;

FIGS. 8a and 8b comprise a flowchart illustrating the sequence of operations involved in implementing a discrimination and authentication system according to a preferred embodiment of the present invention;

FIG. 9 is a flow chart illustrating the sequential procedure involved in detecting the presence of a bill adjacent the lower scanhead and the borderline on the side of the bill adjacent to the lower scanhead;

FIG. 10 is a flow chart illustrating the sequential procedure involved in detecting the presence of a bill adjacent the upper scanhead and the borderline on the side of the bill adjacent to the upper scanhead;

FIG. 11a is a flow chart illustrating the sequential procedure involved in the analog-to-digital conversion routine associated with the lower scanhead;

FIG. 11b is a flow chart illustrating the sequential procedure involved in the analog-to-digital conversion routine associated with the upper scanhead;

FIG. 12 is a flow chart illustrating the sequential procedure involved in determining which scanhead is scanning the green side of a U.S. currency bill;

FIG. 13 is a flow chart illustrating the sequence of operations involved in determining the bill denomination from the correlation results;

FIG. 14 is a flow chart illustrating the sequential procedure involved in decelerating and stopping the bill transport system in the event of an error;

FIG. 15a is a graphical illustration of representative characteristic patterns generated by narrow dimension optical scanning of a $1 currency bill in the forward direction;

FIG. 15b is a graphical illustration of representative characteristic patterns generated by narrow dimension optical scanning of a $2 currency bill in the reverse direction;

FIG. 15c is a graphical illustration of representative characteristic patterns generated by narrow dimension optical scanning of a $100 currency bill in the forward direction;

FIG. 15d is a graph illustrating component patterns generated by scanning old and new $20 bills according a second method according to a preferred embodiment of the present invention;

FIG. 15e is a graph illustrating an pattern for a $20 bill scanned in the forward direction derived by averaging the patterns of FIG. 15d according a second method according to a preferred embodiment of the present invention;

FIGS. 16a-16e are graphical illustrations of the effect produced on correlation pattern by using the progressive shifting technique, according to an embodiment of this invention;

FIGS. 17a-17c are a flowchart illustrating a preferred embodiment of a modified pattern generation method according to the present invention;

FIG. 18a is a flow chart illustrating the sequential procedure involved in the execution of multiple correlations of the scan data from a single bill;

FIG. 18b is a flow chart illustrating a modified sequential procedure of that of FIG. 18a;

FIG. 19a is a flow chart illustrating the sequence of operations involved in determining the bill denomination from the correlation results using data retrieved from the green side of U.S. bills according to one preferred embodiment of the present invention;

FIGS. 19b and 19c are a flow chart illustrating the sequence of operations involved in determining the bill denomination from the correlation results using data retrieved from the black side of U.S. bills;

FIG. 20a is an enlarged vertical section taken approximately through the center of the machine, but showing the various transport rolls in side elevation;

FIG. 20b is a top plan view of the interior mechanism of the machine of FIG. 1 for transporting bills across the optical scanheads, and also showing the stacking wheels at the front of the machine;

FIG. 21a is an enlarged perspective view of the bill transport mechanism which receives bills from the stripping wheels in the machine of FIG. 1;

FIG. 21b is a cross-sectional view of the bill transport mechanism depicted in FIG. 21 along line 21b;

FIG. 22 is a side elevation of the machine of FIG. 1, with the side panel of the housing removed;

FIG. 23 is an enlarged bottom plan view of the lower support member in the machine of FIG. 1 and the passive transport rolls mounted on that member;

FIG. 24 is a sectional view taken across the center of the bottom support member of FIG. 23 across the narrow dimension thereof;

FIG. 25 is an end elevation of the upper support member which includes the upper scanhead in the machine of FIG. 1, and the sectional view of the lower support member mounted beneath the upper support member;

FIG. 26 is a section taken through the centers of both the upper and lower support members, along the long dimension of the lower support member shown in FIG. 23;

FIG. 27 is a top plan view of the upper support member which includes the upper scanhead;

FIG. 28 is a bottom plan view of the upper support member which includes the upper scanhead;

FIG. 29 is an illustration of the light distribution produced about one of the optical scanheads;

FIGS. 30a and 30b are diagrammatic illustrations of the location of two auxiliary photo sensors relative to a bill passed thereover by the transport and scanning mechanism shown in FIGS. 20a-28;

FIG. 31 is a flow chart illustrating the sequential procedure involved in a ramp-up routine for increasing the transport speed of the bill transport mechanism from zero to top speed;

FIG. 32 is a flow chart illustrating the sequential procedure involved in a ramp-to-slow-speed routine for decreasing the transport speed of the bill transport mechanism from top speed to slow speed;

FIG. 33 is a flow chart illustrating the sequential procedure involved in a ramp-to-zero-speed routine for decreasing the transport speed of the bill transport mechanism to zero;

FIG. 34 is a flow chart illustrating the sequential procedure involved in a pause-after-ramp routine for delaying the feedback loop while the bill transport mechanism changes speeds;

FIG. 35 is a flow chart illustrating the sequential procedure involved in a feedback loop routine for monitoring and stabilizing the transport speed of the bill transport mechanism;

FIG. 36 is a flow chart illustrating the sequential procedure involved in a doubles detection routine for detecting overlapped bills;

FIG. 37 is a flow chart illustrating the sequential procedure involved in a routine for detecting sample data representing dark blemishes on a bill;

FIG. 38 is a flow chart illustrating the sequential procedure involved in a routine for maintaining a desired readhead voltage level;

FIG. 39 is a top view of a bill and size determining sensors according to a preferred embodiment of the present invention;

FIG. 40 is a top view of a bill illustrating multiple areas to be optically scanned on a bill according to a preferred embodiment of the present invention;

FIG. 41a is a graph illustrating a scanned pattern which is offset from a corresponding master pattern;

FIG. 41b is a graph illustrating the same patterns of FIG. 41a after the scanned pattern is shifted relative to the master pattern;

FIG. 42 is a side elevation of a multiple scanhead arrangement according to a preferred embodiment of the present invention;

FIG. 43 is a side elevation of a multiple scanhead arrangement according to another preferred embodiment of the present invention;

FIG. 44 is a side elevation of a multiple scanhead arrangement according to another preferred embodiment of the present invention;

FIG. 45 is a side elevation of a multiple scanhead arrangement according to another preferred embodiment of the present invention;

FIG. 46 is a top view of a staggered scanhead arrangement according to a preferred embodiment of the present invention;

FIG. 47a is a top view of a linear array scanhead according to a preferred embodiment of the present invention illustrating a bill being fed in a centered fashion;

FIG. 47b is a side view of a linear array scanhead according to a preferred embodiment of the present invention illustrating a bill being fed in a centered fashion;

FIG. 48 is a top view of a linear array scanhead according to another preferred embodiment of the present invention illustrating a bill being fed in a non-centered fashion;

FIG. 49 is a top view of a linear array scanhead according to another preferred embodiment of the present invention illustrating a bill being fed in a skewed fashion;

FIGS. 50a and 50b are a flowchart of the operation of a currency discrimination system according to a preferred embodiment of the present invention;

FIG. 51 is a top view of a triple scanhead arrangement utilized in a discriminating device able to discriminate both Canadian and German bills according to a preferred embodiment of the present invention;

FIG. 52 is a top view of Canadian bill illustrating the areas scanned by the triple scanhead arrangement of FIG. 51 according to a preferred embodiment of the present invention;

FIG. 53 is a flowchart of the threshold tests utilized in calling the denomination of a Canadian bill according to a preferred embodiment of the present invention;

FIG. 54a illustrates the general areas scanned in generating master 10 DM German patterns according to a preferred embodiment of the present invention;

FIG. 54b illustrates the general areas scanned in generating master 20 DM, 50 DM, and 100 DM German patterns according to a preferred embodiment of the present invention;

FIG. 55 is a flowchart of the threshold tests utilized in calling the denomination of a German bill;

FIG. 56 is a functional block diagram illustrating a first embodiment of a document authenticator and discriminator;

FIG. 57 is a functional block diagram illustrating a second embodiment of a document authenticator and discriminator;

FIG. 58a is a side view of a document authenticating system utilizing ultraviolet light;

FIG. 58b is a top view of the system of FIG. 58a along the direction 58b;

FIG. 58c is a top view of the system of FIG. 58a along the direction 58c; and

FIG. 59 is a functional block diagram of the optical and electronic components of the document authenticating system of FIGS. 58a-58c.

FIG. 60 is perspective view of a disc-type coin sorter embodying the present invention, with a top portion thereof broken away to show internal structure;

FIG. 61 is an enlarged horizontal section taken generally along line 61--61 in FIG. 60;

FIG. 62 is an enlarged section taken generally along line 62--62 in FIG. 61, showing the coins in full elevation;

FIG. 63 is an enlarged section taken generally along line 63--63 in FIG. 61, showing in full elevation a nickel registered with an ejection recess;

FIG. 64 is a diagrammatic cross-section of a coin and an improved coin discrimination sensor embodying the invention;

FIG. 65 is a schematic circuit diagram of the coin discrimination sensor of FIG. 64;

FIG. 66 is a diagrammatic perspective view of the coils in the coin discrimination sensor of FIG. 64;

FIG. 67a is a circuit diagram of a detector circuit for use with the discrimination sensor of this invention;

FIG. 67b is a waveform diagram of the input signals supplied to the circuit of FIG. 67a;

FIG. 68 is a perspective view of an outboard shunting device embodying the present invention;

FIG. 69 is a section taken generally along line 69--69 in FIG. 68;

FIG. 70 is a section taken generally along line 70--70 in FIG. 68, showing a movable partition in a nondiverting position; and

FIG. 71 is the same section illustrated in FIG. 70, showing the movable portion in a diverting position.

DETAILED DESCRIPTION OF THE PREFERRED 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 the invention as defined by the appended claims.

Turning now to the drawings and referring first to FIGS. 1a, 1b and 1c, there is shown an automatic teller machine ("ATM") having a bill deposit receptacle 1 as well as a bill withdrawal or return slot 2. The ATM has the conventional slot 3 for receiving the customer's identification card so that the data on the card can be automatically read by a card reader. A video display 4 provides the customer with a menu of options, and also prompts the customer to carry out the various actions required to execute a transaction, including the use of a keypad 5.

The illustrative ATM also has a coin deposit receptacle 6 and a coin return pocket 7. The deposit receptacles 1 and 6 are normally retracted within the machine but are advanced to their open positions (shown in FIG. 1a) when a customer initiates a transaction and selects a "cash deposit" mode of operation. Bills and coins can then be deposited by the customer into the deposit receptacles 1 and 6, respectively.

After the customer has placed a stack of bills into the receptacle 1, the customer is prompted to push that receptacle into the machine, to its retracted position. This inward movement of the receptacle 1 positions the stack of bills at the feed station of a bill scanning and counting module 8 which automatically feeds, counts, scans and authenticates the bills one at a time at a high speed (e.g., at least 350 bills per minute). The bills that are recognized by the scanning module 8 are delivered to a conventional currency canister 9 (FIG. 1c) which is periodically removed from the machine and replaced with an empty canister. When a bill cannot be recognized by the scanning module, a diverter 10 is actuated to divert the unidentified bill to the return slot 2 so that it can be removed from the machine by the customer. Alternatively, unrecognizable bills can be diverted to a separate currency canister rather than being returned to the customer. Bills that are detected to be counterfeit are treated in the same manner as unrecognizable bills.

Though not shown in FIGS. 1a-1c, the bill transport system may also include an escrow holding area where the bills being processed in a pending deposit transaction are held until the transaction is complete. Then if the declared balance entered by the customer does not agree with the amount verified by the machine, the entire stack of bills can be returned to the customer. If desired, this decision can be controlled by the customer via the keypad.

When coins are deposited by the customer in the receptacle 6, the customer again is prompted to push that receptacle into the machine. This causes the coins to be fed by gravity into the receiving hopper of a coin-sorting and counting module 11 which physically separates the coins by size (denomination) while separately counting the number of coins of each denomination in each separate transaction. The module 11 also includes a coin discriminator which detects coins that are counterfeit or otherwise non-genuine. These unacceptable coins are discharged from the sorter at a common exit, and the coins from that exit are guided by a tube 12 to the coin return slot 7.

The ATM also preferably includes a conventional loose currency dispensing module 13 for dispensing loose bills, and/or a strapped currency dispensing module 14 for dispensing strapped currency, into a receptacle 15 at the front of the machine, in response to a withdrawal transaction. If desired, a loose coin dispensing module 16 and/or a rolled coin dispensing module 17, may also be included for dispensing coins via the coin return pocket 7. Additional modules that may be included in the ATM or a redemption machine using the same system are modules for verifying and accepting checks, food stamps, tokens and/or tickets containing bar codes.

As will be described in more detail below, each of the modules 8 and 11 accumulates data representing both the number and the value of each separate currency item processed by these modules in each separate transaction. At the end of each transaction, this data and the account number for the transaction are downloaded to an associated cash accounting system by a modem link, so that the customer's account can be immediately adjusted to reflect both the deposits and the withdrawals effected by the current transaction. Alternatively, the data from the currency-processing modules and the card reader can be temporarily stored within a temporary memory within the ATM, so that the data can be downloaded at intervals controlled by the computing system on which the cash accounting system is run.

FIG. 1d is a flow chart of a subroutine for transferring data from the ATM to the cash accounting system. This subroutine is entered at step 10a each time a customer inserts an identification card into the ATM. The customer's account number is stored at step 10b, and step 10c then initiates a transaction by prompting the customer to select from a menu of available deposit or withdrawal transactions, and step 10d then monitors the ATM system to determine when the transaction is complete. When the answer is affirmative, the bill deposit amount B.sub.d, the bill withdrawal amount B.sub.w, the coin deposit amount C.sub.d, and the coin withdrawal amount C.sub.w are stored at steps 10e, 10f, 10g and 10h, and then downloaded to the cash accounting system at step 10i. If desired, these amounts may be loaded into a buffer memory for later retrieval by the computer that controls the cash accounting system. The cash accounting system then enters these amounts in the customer's account, and immediately adjusts the balance in that account accordingly.

A subroutine for executing a cash deposit of bills is shown in FIG. 1e. When this type of transaction is selected by the customer, the video display prompts the customer to place the stack of bills being deposited into the receptacle 1 and to push that receptacle into the machine. The bill counting and scanning module then automatically withdraws one bill at a time from the bottom of the stack, and scans each bill for denomination and authentication.

Each successive bill that is withdrawn from the deposit stack is scanned at step 11a to determine the denomination of the bill, and checked for authentication at step 11b. The results of the authentication are checked at step 11c. If the bill cannot be authenticated, it is a counterfeit suspect and thus step 11c produces an affirmative answer. This advances the system to step 11d, which determines whether the owner of the ATM or redemption machine has opted to return counterfeit-suspect bills to the customer. If this option has been selected, the suspect bill is returned to the customer at step lie. If the return option has not been selected at step 11d, the resulting negative response advances the system to step 11f which transports the bill to a suspect bill canister.

If the bill is not a counterfeit suspect, the resulting negative answer at step 11c advances the system to step 11g to check the results of the scanning step. This step determines whether the bill is a "no call," i.e., whether it was impossible for the scanning operation to determine the denomination of the bill. If the bill is a "no call," step 11g produces an affirmative answer, and step 11h determines whether the option to return "no calls" to the customer has been selected. If the answer is affirmative, the "no call" bill is returned to the customer at step 11e. If the answer is negative, the "no call" bill is transported to a "no call" canister at step 11i.

If the denomination of the bill has been determined by the scanner, the resulting negative response at step 11g causes the counter for that particular denomination to be incremented at step 11j. The dollar value of that denomination is then added to the verified deposit amount at step 11k to maintain a current cumulative total of the currency deposit that is being processed. The bill is then transported to an escrow holding area for the current deposit, at step 11l.

To determine when the processing of a deposit has been completed, step 11m determines when the last bill in a deposited stack of bills has been counted. When this step produces an affirmative answer, step 11m then determines whether the final verified deposit amount agrees with the declared balance that was entered by the customer through the key pad. If the answer is affirmative, the deposited bills are transported from the escrow holding area to a verified deposit canister at step 11o. A negative answer at step 11n advances the system to step 11p where again the system determines whether a "return" option has been selected. This option may be preselected by the owner of the ATM or redemption machine, or it may be an option that is available to the customer. In any event, if the option has been selected, the bills are returned to the customer at step 11q to enable the customer to determine why the verified deposit amount does not agree with the customer's declared balance. At this time, the verified deposit amount is displayed to the customer along with an appropriate message. A negative response at step lip causes the bills to be transported from the escrow holding area to a disputed balance canister at step 11r.

FIG. 1f illustrates a modification of the routine of FIG. 1e which permits the use of a single storage canister for all of the bills, regardless of whether they are verified bills, no calls, or counterfeit suspects. In this system the various bills are identified within the single canister by placing different colored markers on top of different bills. These markers are inserted into the bill transport path so that they follow the respective bills to be marked into the canister. Specifically, a first marker, e.g., a marker of a first color, is inserted at step 11s following an affirmative response at step 11c and a negative response at step 11d to indicate that the bill is a counterfeit suspect that is not to be returned to the customer. A second type of marker, e.g. a marker of a second color, is inserted at step 11t in response to an affirmative response at step 11g and a negative answer at step 11h, to indicate that the marked bill is a counterfeit suspect. A third type of marker, e.g., of a third color, is inserted at step 11u in response to negative answers at steps 11n and 11p, to indicate that the marked batch of bills represents a deposit whose verified amount did not agree with the customer's declared balance. Because this third type of marker identifies a batch of bills instead of a single bill, it is necessary to insert a marker at both the beginning and end of the marked batch.

In the event that the customer wishes to deposit "no call" bills that are returned to the customer, the customer may key in the value and number of such bills and deposit them in an envelope for later verification by the bank. A message on the display screen may advise the customer of this option. For example, if four $10 bills are returned, and then re-deposited by the customer in an envelope, the customer may press a "$10" key four times. The customer then receives immediate credit for all the bills denominated and authenticated by the scanner. Credit for the re-deposited "no call" bills is given only after the bank picks up the deposit envelope and manually verifies the amount. Alternatively, at least preferred customers can be given full credit immediately, subject to later verification, or immediate credit can be given up to a certain dollar limit. In the case of counterfeit bills that are not returned to the customer, the customer can be notified of the detection of a counterfeit suspect at the ATM or later by a written notice or personal call, depending upon the preferences of the financial institution.

The ATM or redemption machine may also have a "verify mode" in which it simply denominates and totals all the currency (bills and/or coins) deposited by the customer and returns it all to the customer. If the customer agrees with the amount and wishes to proceed with an actual deposit, the customer selects the "deposit mode" and re-deposits the same batch of currency in the machine. Alternatively, the "verify mode" may hold the initially deposited currency in an escrow area until the customer decides whether to proceed with an actual deposit.

In the event that the machine jams or otherwise malfunctions while currency is being processed, the message display screen advises the customer of the number and value of the currency items processed prior to the jam. The customer is instructed to retrieve the currency not yet processed and to manually deposit it in a sealed envelope which is then deposited into the machine for subsequent verification. The machine malfunction is automatically reported via modem to the home office.

Referring now to FIG. 2a, there is shown a preferred embodiment of a currency scanning and counting module 8. The module 8 includes a bill accepting station 12 for receiving stacks of currency bills from the deposit receptacle 1. A feed mechanism functions to pick out or separate one bill at a time for transfer to a bill transport mechanism 16 (FIG. 2a) which transports each bill along a precisely predetermined transport path, between a pair of scanheads 18a, 18b where the denomination of the bill is identified. In the preferred embodiment, bills are scanned and identified at a rate in excess of 350 bills per minute. In the preferred embodiment depicted, each scanhead 18a, 18b is an optical scanhead that scans for characteristic information from a scanned bill 17 which is used to identify the denomination of the bill. The scanned bill 17 is then transported to a cassette or bill stacking station 20 where bills so processed are stacked for subsequent removal.

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 the transport path adjacent the scanhead 18. Light reflected off the illuminated strip 24 is sensed by a photodetector 26 positioned between the two light sources. The analog output of the photodetector 26 is converted into a digital signal by means of an analog-to-digital (ADC) convertor unit 28 whose output is fed as a digital input to a central processing unit (CPU) 30.

While the scanheads 18a, 18b of FIG. 2a are optical scanheads, it should be understood that the scanheads and the signal processing system may be designed to detect a variety of characteristic information from currency bills. Additionally, the scanheads may employ a variety of detection means such as magnetic, optical, electrical conductivity, and capacitive sensors. Use of such sensors is discussed in more detail below (see, e.g., FIG. 2d).

Referring again to FIG. 2a, the bill transport path is defined in such a way that the transport mechanism 16 moves currency bills with the narrow dimension of the bills being parallel to the transport path and the scan direction. Alternatively, the system may be designed to scan bills along their long dimension or along a skewed dimension. As a bill 17 traverses the scanheads 18a, 18b, the coherent light strip 24 effectively scans the bill across the narrow dimension of the bill. In the preferred embodiment depicted, the transport path is so arranged that a currency bill 17 is scanned across a central section of the bill along its narrow dimension, as shown in FIG. 2a. Each scanhead functions to detect light reflected from the bill as it moves across the illuminated light strip 24 and to provide an analog representation of the variation in reflected light, which, in turn, represents the variation in the dark and light content of the printed pattern or indicia on the surface of the bill. This variation in light reflected from the narrow-dimension scanning of the bills serves as a measure for distinguishing, with a high degree of confidence, among a plurality of currency denominations which the system is programmed to handle.

A series of such detected reflectance signals are obtained across the narrow dimension of the bill, or across a selected segment thereof, and the resulting analog signals are digitized under control of the CPU 30 to yield a fixed number of digital reflectance data samples. The data samples are then subjected to a normalizing routine for processing the sampled data for improved correlation and for smoothing out variations due to "contrast" fluctuations in the printed pattern existing on the bill surface. 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 narrow dimension scanning of successive bills, the reflectance sampling process is preferably controlled through the CPU 30 by means of an optical encoder 32 which is linked to the bill transport mechanism 16 and precisely tracks the physical movement of the bill 17 between the scanheads 18a, 18b. More specifically, the optical encoder 32 is linked to the rotary motion of the drive motor which generates the movement imparted to the bill along the transport path. In addition, the mechanics of the feed mechanism ensure that positive contact is maintained between the bill and the transport path, particularly when the bill is being scanned by the scanheads. Under these conditions, the optical encoder 32 is capable of precisely tracking the movement of the bill 17 relative to the light strips 24 generated by the scanheads 18a, 18b by monitoring the rotary motion of the drive motor.

The outputs of the photodetectors 26 are monitored by the CPU 30 to initially detect the presence of the bill adjacent the scanheads and, subsequently, to detect the starting point of the printed pattern on the bill, as represented by the thin borderline 17a which typically encloses the printed indicia on U.S. currency bills. Once the borderline 17 a has been detected, the optical encoder 32 is used to control the timing and number of reflectance samples that are obtained from the outputs of the photodetectors 26 as the bill 17 moves across the scanheads.

FIG. 2b illustrates a modified currency scanning and counting device similar to that of FIG. 2a but having a scanhead on only a single side of the transport path.

FIG. 2c illustrates another modified currency scanning and counting device similar to that of FIG. 2b but illustrating feeding and scanning of bills along their wide direction.

As illustrated in FIGS. 2b-2c, the transport mechanism 16 moves currency bills with a preselected one of their two dimensions (narrow or wide) being parallel to the transport path and the scan direction. FIGS. 2b and 4a illustrate bills oriented with their narrow dimension "W" parallel to the direction of movement and scanning, while FIGS. 2c and 4b illustrate bills oriented with their wide dimension "L" parallel to the direction of movement and scanning.

Referring now to FIG. 2d, there is shown a functional block diagram illustrating a preferred embodiment of a currency discriminating and authenticating system. The operation of the system of FIG. 2d is the same as that of FIG. 2a except as modified below. The system includes a bill accepting station 12 where stacks of currency bills that need to be identified, authenticated, and counted are positioned. Accepted bills are acted upon by a bill separating station 14 which functions to pick out or separate one bill at a time for transfer to a bill transport mechanism 16 which transports each bill along a precisely predetermined transport path, across two scanheads 18 and 39 where the currency denomination of the bill is identified and the genuineness of the bill is authenticated. In the preferred embodiment depicted, scanhead 18 is an optical scanhead that scans for a first type of characteristic information from a scanned bill 17 which is used to identify the bill's denomination. A second scanhead 39 scans for a second type of characteristic information from the scanned bill 17. While the illustrated scanheads 18 and 39 are separate and distinct, they may be incorporated into a single scanhead. For example, where the first characteristic sensed is intensity of reflected light and the second characteristic sensed is color, a single optical scanhead having a plurality of detectors, one or more without filters and one or more with colored filters, may be employed (U.S. Pat. No. 4,992,860 incorporated herein by reference). The scanned bill is then transported to a bill stacking station 20 where bills so processed are stacked for subsequent removal.

The optical scanhead 18 of the embodiment depicted in FIG. 2d comprises at least one light source 22 directing a beam of coherent light downwardly onto the bill transport path so as to illuminate a substantially rectangular light strip 24 upon a currency bill 17 positioned on the transport path below the scanhead 18. Light reflected off the illuminated strip 24 is sensed by a photodetector 26 positioned directly above the strip. The analog output of photodetector 26 is converted into a digital signal by means of an analog-to-digital (ADC) convertor unit 28 whose output is fed as a digital input to a central processing unit (CPU) 30.

The second scanhead 39 comprises at least one detector 41 for sensing a second type of characteristic information from a bill. The analog output of the detector 41 is converted into a digital signal by means of a second analog-to-digital converter 43 whose output is also fed as a digital input to the central processing unit (CPU) 30.

While the scanhead 18 in the embodiment of FIG. 2d is an optical scanhead, it should be understood that the first and second scanheads 18 and 39 may be designed to detect a variety of characteristic information from currency bills. Additionally these scanheads may employ a variety of detection means such as magnetic or optical sensors. For example, a variety of currency characteristics can be measured using magnetic sensing. These include detection of patterns of changes in magnetic flux (U.S. Pat. No. 3,280,974), patterns of vertical grid lines in the portrait area of bills (U.S. Pat. No. 3,870,629), the presence of a security thread (U.S. Pat. No. 5,151,607), total amount of magnetizable material of a bill (U.S. Pat. No. 4,617,458), patterns from sensing the strength of magnetic fields along a bill (U.S. Pat. No. 4,593,184), and other patterns and counts from scanning different portions of the bill such as the area in which the denomination is written out (U.S. Pat. No. 4,356,473).

With regard to optical sensing, a variety of currency characteristics can be measured such as density (U.S. Pat. No. 4,381,447), color (U.S. Pat. Nos. 4,490,846; 3,496,370; 3,480,785), length and thickness (U.S. Pat. No. 4,255,651), the presence of a security thread (U.S. Pat. No. 5,151,607) and holes (U.S. Pat. No. 4,381,447), and other patterns of reflectance and transmission (U.S. Pat. No. 3,496,370; 3,679,314; 3,870,629; 4,179,685). Color detection techniques may employ color filters, colored lamps, and/or dichroic beamsplitters (U.S. Pat. Nos. 4,841,358; 4,658,289; 4,716,456; 4,825,246, 4,992,860 and EP 325,364). Prescribed hues or intensities of a given color may be detected. Reflection and/or fluorescence of ultraviolet light may also be used, as described in detail below. Absorption of infrared light may also be used as an authenticating technique.

In addition to magnetic and optical sensing, other techniques of detecting characteristic information of currency include electrical conductivity sensing, capacitive sensing (U.S. Pat. No. 5,122,754 [watermark, security thread]; U.S. Pat. No. 3,764,899 [thickness]; U.S. Pat. No. 3,815,021 [dielectric properties]; U.S. Pat. No. 5,151,607 [security thread]), and mechanical sensing (U.S. Pat. Nos. 4,381,447 [limpness]; U.S. Pat. No. 4,255,651 [thickness]), and hologram, kinegram and moviegram sensing.

The detection of the borderline 17a realizes improved discrimination efficiency in systems designed to accommodate U.S. currency since the borderline 17a serves as an absolute reference point for initiation of sampling. When the edge of a bill is used as a reference point, relative displacement of sampling points can occur because of the random manner in which the distance from the edge to the borderline 17a varies from bill to bill due to the relatively large range of tolerances permitted during printing and cutting of currency bills. As a result, it becomes difficult to establish direct correspondence between sample points in successive bill scans and the discrimination efficiency is adversely affected. Accordingly, the modified pattern generation method discussed below is useful in discrimination systems designed to accommodate bills other than U.S. currency because many non-U.S. bills lack a borderline around the printed indicia on their bills. Likewise, the modified pattern generation method may be important in discrimination systems designed to accommodate bills other than U.S. currency because the printed indicia of many non-U.S. bills lack sharply defined edges which in turns inhibits using the edge of the printed indicia of a bill as a trigger for the initiation of the scanning process and instead promotes reliance on using the edge of the bill itself as the trigger for the initiation of the scanning process.

The use of the optical encoder 32 for controlling the sampling process relative to the physical movement of a bill 17 across the scanheads 18a, 18b is also advantageous in that the encoder 32 can be used to provide a predetermined delay following detection of the borderline 17a prior to initiation of samples. The encoder delay can be adjusted in such a way that the bill 17 is scanned only across those segments which contain the most distinguishable printed indicia relative to the different currency denominations.

In the case of U.S. currency, for instance, it has been determined that the central, approximately two-inch (approximately 5 cm) portion of currency bills, as scanned across the central section of the narrow dimension of the bill, provides sufficient data for distinguishing among the various U.S. currency denominations. Accordingly, the optical encoder can be used to control the scanning process so that reflectance samples are taken for a set period of time and only after a certain period of time has elapsed after the borderline 17a is detected, thereby restricting the scanning to the desired central portion of the narrow dimension of the bill.

FIGS. 3-5b illustrate the scanning process in more detail. Referring to FIG. 4a, as a bill 17 is advanced in a direction parallel to the narrow edges of the bill, scanning via a slit in the scanhead 18a or 18b is effected along a segment S of the central portion of the bill 17. This segment S begins a fixed distance D inboard of the borderline 17a. As the bill 17 traverses the scanhead, a strip s of the segment S is always illuminated, and the photodetector 26 produces a continuous output signal which is proportional to the intensity of the light reflected from the illuminated strip s at any given instant. This output is sampled at intervals controlled by the encoder, so that the sampling intervals are precisely synchronized with the movement of the bill across the scanhead. FIG. 4b is similar to FIG. 4a but illustrates scanning along the wide dimension of the bill 17.

As illustrated in FIGS. 3, 5a, and 5b, it is preferred that the sampling intervals be selected so that the strips s that are illuminated for successive samples overlap one another. The odd-numbered and even-numbered sample strips have been separated in FIGS. 3, 5a, and 5b to more clearly illustrate this overlap. For example, the first and second strips s1 and s2 overlap each other, the second and third strips s2 and s3 overlap each other, and so on. Each adjacent pair of strips overlap each other. In the illustrative example, this is accomplished by sampling strips that are 0.050 inch (0.127 cm) wide at 0.029 inch (0.074 cm) intervals, along a segment S that is 1.83 inch (4.65 cm) long (64 samples).

FIGS. 6a and 6b illustrate two opposing surfaces of U.S. bills. The printed patterns on the black and green surfaces of the bill are each enclosed by respective thin borderlines B.sub.1 and B.sub.2. As a bill is advanced in a direction parallel to the narrow edges of the bill, scanning via the wide slit of one of the scanheads is effected along a segment S.sub.A of the central portion of the black surface of the bill (FIG. 6a). As previously stated, the orientation of the bill along the transport path determines whether the upper or lower scanhead scans the black surface of the bill. This segment S.sub.A begins a fixed distance D.sub.1 inboard of the borderline B.sub.1, which is located a distance W.sub.1 from the edge of the bill. The scanning along segment S.sub.A is as described in connection with FIGS. 3, 4a, and 5a.

Similarly, the other of the two scanheads scans a segment S.sub.B of the central portion of the green surface of the bill (FIG. 6b). The orientation of the bill along the transport path determines whether the upper or lower scanhead scans the green surface of the bill. This segment S.sub.B begins a fixed distance D.sub.2 inboard of the border line B.sub.2, which is located a distance W.sub.2 from the edge of the bill. For U.S. currency, the distance W.sub.2 on the green surface is greater than the distance W.sub.1 on the black surface. It is this feature of U.S. currency which permits one to determine the orientation of the bill relative to the upper and lower scanheads 18, thereby permitting one to select only the data samples corresponding to the green surface for correlation to the master characteristic patterns in the EPROM 34. The scanning along segment S.sub.B is as described in connection with FIGS. 3, 4a, and 5a.

FIGS. 6c and 6d are side elevations of FIG. 2a. FIG. 6c shows the first surface of a bill scanned by an upper scanhead and the second surface of the bill scanned by a lower scanhead, while FIG. 6d shows the first surface of a bill scanned by a lower scanhead and the second surface of the bill scanned by an upper scanhead. FIGS. 6c and 6d illustrate the pair of optical scanheads 18a, 18b disposed on opposite sides-of the transport path to permit optical scanning of both surfaces of a bill. With respect to U.S currency, these opposing surfaces correspond to the black and green surfaces of a bill. One of the optical scanheads 18 (the "upper" scanhead 18a in FIGS. 6c-6d) is positioned above the transport path and illuminates a light strip upon a first surface of the bill, while the other of the optical scanheads 18 (the "lower" scanhead 18b in FIGS. 6c-6d) is positioned below the transport path and illuminates a light strip upon the second surface of the bill. The surface of the bill scanned by each scanhead 18 is determined by the orientation of the bill relative to the scanheads 18. The upper scanhead 18a is located slightly upstream relative to the lower scanhead 18b.

The photodetector of the upper scanhead 18a produces a first analog output corresponding to the first surface of the bill, while the photodetector of the lower scanhead 18b produces a second analog output corresponding to the second surface of the bill. The first and second analog outputs are converted into respective first and second digital outputs by means of respective analog-to-digital (ADC) convertor units 28 whose outputs are fed as digital inputs to a central processing unit (CPU) 30. As described in detail below, the CPU 30 uses the sequence of operations illustrated in FIG. 12 to determine which of the first and second digital outputs corresponds to the green surface of the bill, and then selects the "green" digital output for subsequent correlation to a series of master characteristic patterns stored in EPROM 34. As explained below, the master characteristic patterns are preferably generated by performing scans on the green surfaces, not black surfaces, of bills of different denominations. According to a preferred embodiment, the analog output corresponding to the black surface of the bill is not used for subsequent correlation.

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 a preferred 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. 2a), for each detectable currency denomination. According to one preferred embodiment these 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 the green surface of the bill and taken along both the "forward" and "reverse" directions relative to the pattern printed on the bill. Alternatively, the optical scanning may be performed on the black side of U.S. currency bills or on either surface of foreign bills. Additionally, the optical scanning may be performed on both sides of a bill.

In adapting this technique to U.S. currency, for example, sets of stored intensity signal samples are generated and stored for seven different denominations of U.S. currency, i.e., $1, $2, $5, $10, $20, $50 and $100. For bills which produce significant pattern changes when shifted slightly to the left or right, such as the $2, the $10 and/or the $100 bills in U.S. currency, it is preferred to store two green-side patterns for each of the "forward" and "reverse" directions, each pair of patterns for the same direction represent two scan areas that are slightly displaced from each other along the long dimension of the bill. Accordingly, a set of 16 [or 18] different green-side master characteristic patterns are stored within the EPROM for subsequent correlation purposes (four master patterns for the $10 bill [or four master patterns for the $10 bill and the $2 bill and/or the $100 bill] and two master patterns for each of the other denominations). The generation of the master patterns is discussed in more detail below. Once the master patterns have been stored, the pattern generated by scanning a bill under test is compared by the CPU 30 with each of the 16 [or 18] master patterns of stored intensity signal samples to generate, for each comparison, a correlation number representing the extent of correlation, i.e., similarity between corresponding ones of the plurality of data samples, for the sets of data being compared.

According to a preferred embodiment, in addition to the above set of 18 original green-side master patterns, five more sets of green-side master patterns are stored in memory. These sets are explained more fully in conjunction with FIGS. 18a and 18b below.

The CPU 30 is programmed to identify the denomination of the scanned bill as corresponding to the set of stored intensity signal samples for which the correlation number resulting from pattern comparison is found to be the highest. In order to preclude the possibility of mischaracterizing the denomination of a scanned bill, as well as to reduce the possibility of spurious notes being identified as belonging to a valid-denomination, a bi-level threshold of correlation is used as the basis for making a "positive" call. If a "positive" call can not be made for a scanned bill, an error signal is generated.

According to a preferred embodiment, master patterns are also stored for selected denominations corresponding to scans along the black side of U.S. bills. More particularly, according to a preferred embodiment, multiple black-side master patterns are stored for $20, $50 and $100 bills. For each of these denominations, three master patterns are stored for scans in the forward and reverse directions for a total of six patterns for each denomination. For a given scan direction, black-side master patterns are generated by scanning a corresponding denominated bill along a segment located about the center of the narrow dimension of the bill, a segment slightly displaced (0.2 inches) to the left of center, and a segment slightly displaced (0.2 inches) to the right of center. When the scanned pattern generated from the green side of a test bill fails to sufficiently correlate with one of the green-side master patterns, the scanned pattern generated from the black side of a test bill is then compared to black-side master patterns in some situations as described in more detail below in conjunction with FIGS. 19a-19c.

Using the above sensing and correlation approach, the CPU 30 is programmed to count the number of bills belonging to a particular currency denomination as part of a given set of bills that 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 (FIGS. 2a and FIG. 2b) which is adapted to provide a display of the number of bills counted, the breakdown of the bills in terms of currency denomination, and the aggregate total of the 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.

Referring again to the preferred embodiment depicted in FIG. 2d, as a result of the first comparison described above based on the reflected light intensity information retrieved by scanhead 18, the CPU 30 will have either determined the denomination of the scanned bill 17 or determined that the first scanned signal samples fail to sufficiently correlate with any of the sets of stored intensity signal samples in which case an error is generated. Provided that an error has not been generated as a result of this first comparison based on reflected light intensity characteristics, a second comparison is performed. This second comparison is performed based on a second type of characteristic information, such as alternate reflected light properties, similar reflected light properties at alternate locations of a bill, light transmissivity properties, various magnetic properties of a bill, the presence of a security thread embedded within a bill, the color of a bill, the thickness or other dimension of a bill, etc. The second type of characteristic information is retrieved from a scanned bill by the second scanhead 39. The scanning and processing by scanhead 39 may be controlled in a manner similar to that described above with regard to scanhead 18.

In addition to the sets of stored first characteristic information, in this example stored intensity signal samples, the EPROM 34 stores sets of stored second characteristic information for genuine bills of the different denominations which the system 10 is capable of handling. Based on the denomination indicated by the first comparison, the CPU 30 retrieves the set or sets of stored second characteristic data for a genuine bill of the denomination so indicated and compares the retrieved information with the scanned second characteristic information. If sufficient correlation exists between the retrieved information and the scanned information, the CPU 30 verifies the genuineness of the scanned bill 17. Otherwise, the CPU generates an error. While the preferred embodiment illustrated in FIG. 2d depicts a single CPU 30 for making comparisons of first and second characteristic information and a single EPROM 34 for storing first and second characteristic information, it is understood that two or more CPUs and/or EPROMs could be used, including one CPU for making first characteristic information comparisons and a second CPU for making second characteristic information comparisons. Using the above sensing and correlation approach, the CPU 30 is programmed to count the number of bills belonging to a particular currency denomination whose genuineness has been verified as part of a given set of bills that 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.

Referring now to FIGS. 7a and 7b, there is shown a representation, in block diagram form, of a preferred circuit arrangement for processing and correlating reflectance data according to the system of this invention. The CPU 30 accepts and processes a variety of input signals including those from the optical encoder 32, the sensor 26 and the erasable programmable read only memory (EPROM) 60. The EPROM 60 has stored within it the correlation program on the basis of which patterns are generated and test patterns compared with stored master programs in order to identify the denomination of test currency. A crystal 40 serves as the time base for the CPU 30, which is also provided with an external reference voltage V.sub.REF 42 on the basis of which peak detection of sensed reflectance data is performed.

According to one embodiment, the CPU 30 also accepts a timer reset signal from a reset unit 44 which, as shown in FIG. 7b, accepts the output voltage from the photodetector 26 and compares it, by means of a threshold detector 44a, relative to a pre-set voltage threshold, typically 5.0 volts, to provide a reset signal which goes "high" when a reflectance value corresponding to the presence of paper is sensed. More specifically, reflectance sampling is based on the premise that no portion of the illuminated light strip (24 in FIG. 2a) is reflected to the photodetector in the absence of a bill positioned below the scanhead. Under these conditions, the output of the photodetector represents a "dark" or "zero" level reading. The photodetector output changes to a "white" reading, typically set to have a value of about 5.0 volts, when the edge of a bill first becomes positioned below the scanhead and falls under the light strip 24. When this occurs, the reset unit 44 provides a "high" signal to the CPU 30 and marks the initiation of the scanning procedure.

The machine-direction dimension, that is, the dimension parallel to the direction of bill movement, of the illuminated strip of light produced by the light sources within the scanhead is set to be relatively small for the initial stage of the scan when the thin borderline is being detected, according to a preferred embodiment. The use of the narrow slit increases the sensitivity with which the reflected light is detected and allows minute variations in the "gray" level reflected off the bill surface to be sensed. This ensures that the thin borderline of the pattern, i.e., the starting point of the printed pattern on the bill, is accurately detected. Once the borderline has been detected, subsequent reflectance sampling is performed on the basis, of a relatively wider light strip in order to completely scan across the narrow dimension of the bill and obtain the desired number of samples, at a rapid rate. The use of a wider slit for the actual sampling also smoothes out the output characteristics of the photodetector and realizes the relatively large magnitude of analog voltage which is desirable for accurate representation and processing of the detected reflectance values.

The CPU 30 processes the output of the sensor 26 through a peak detector 50 which essentially functions to sample the sensor output voltage and hold the highest, i.e., peak, voltage value encountered after the detector has been enabled. For U.S. currency, the peak detector is also adapted to define a scaled voltage on the basis of which the printed borderline on the currency bills is detected. The output of the peak detector 50 is fed to a voltage divider 54 which lowers the peak voltage down to a scaled voltage V.sub.S representing a predefined percentage of this peak value. The voltage V.sub.S is based upon the percentage drop in output voltage of the peak detector as it reflects the transition from the "high" reflectance value resulting from the scanning of the unprinted edge portions of a currency bill to the relatively lower "gray" reflectance value resulting when the thin borderline is encountered. Preferably, the scaled voltage V.sub.S is set to be about 70-80 percent of the peak voltage.

The scaled voltage V.sub.S is supplied to a line detector 56 which is also provided with the incoming instantaneous output of the sensor 26. The line detector 56 compares the two voltages at its input side and generates a signal L.sub.DET which normally stays "low" and goes "high" when the edge of the bill is scanned. The signal L.sub.DET goes "low" when the incoming sensor output reaches the pre-defined percentage of the peak output up to that point, as represented by the voltage V.sub.S. Thus, when the signal L.sub.DET goes "low", it is an indication that the borderline of the bill pattern has been detected. At this point, the CPU 30 initiates the actual reflectance sampling under control of the encoder 32, and the desired fixed number of reflectance samples are obtained as the currency bill moves across the illuminated light strip and is scanned along the central section of its narrow dimension.

When master characteristic patterns are being generated, the reflectance samples resulting from the scanning of one or more genuine bills for each denomination are loaded into corresponding designated sections within a system memory 60, which is preferably an EPROM. During currency discrimination, the reflectance values resulting from the scanning of a test bill are sequentially compared, under control of the correlation program stored within the EPROM 60, with the corresponding master characteristic patterns stored within the EPROM 60. A pattern averaging procedure for scanning bills and generating characteristic patterns is described below in connection with FIGS. 15a-15e.

The interrelation between the use of the first and second type of characteristic information can be seen by considering FIGS. 8a and 8b which comprise a flowchart illustrating the sequence of operations involved in implementing a discrimination and authentication system according to a preferred embodiment of the present invention. Upon the initiation of the sequence of operations (step 1748), reflected light intensity information is retrieved from a bill being scanned (step 1750). Similarly, second characteristic information is also retrieved from the bill being scanned (step 1752). Denomination error and second characteristic error flags are cleared (steps 1753 and 1754).

Next the scanned intensity information is compared to each set of stored intensity information corresponding to genuine bills of all denominations the system is programmed to accommodate (step 1758). For each denomination, a correlation number is calculated. The system then, based on the correlation numbers calculated, determines either the denomination of the scanned bill or generates a denomination error by setting the denomination error flag steps 1760 and 1762). In the case where the denomination error flag is set (step 1762), the process is ended (step 1772). Alternatively, if based on this first comparison, the system is able to determine the denomination of the scanned bill, the system proceeds to compare the scanned second characteristic information with the stored second characteristic information corresponding to the denomination determined by the first comparison (step 1764).

For example, if as a result of the first comparison the scanned bill is determined to be a $20 bill, the scanned second characteristic information is compared to the stored second characteristic information corresponding to a genuine $20 bill. In this manner, the system need not make comparisons with stored second characteristic information for the other denominations the system is programmed to accommodate. If based on this second comparison (step 1764) it is determined that the scanned second characteristic information does not sufficiently match that of the stored second characteristic information (step 1766), then a second characteristic error is generated by setting the second characteristic error flag (step 1768) and the process is ended (step 1772). If the second comparison results in a sufficient match between the scanned and stored second characteristic information (step 1766), then the denomination of the scanned bill is indicated (step 1770) and the process is ended (step 1772).

An example of an interrelationship between authentication based on first and second characteristics can be seen by considering Table 1. The denomination determined by optical scanning of a bill is preferably used to facilitate authentication of the bill by magnetic scanning, using the relationship set forth in Table 1.

                                       TABLE 1
                                     Sensitivity
        Denomination      1       2       3       4        5
        $1               200     250     300      375     450
        $2               100     125     150     225      300
        $5               200     250     300     350      400
        $10              100     125     150     200      250
        $20              120     150     180     270      360
        $50              200     250     300     375      450
        $100             100     125     150     250      350

                             TABLE 2
                 Component Scans by Denomination
    Denomination  Scan Direction    CP1        CP2         CP3
    $1            Forward        -0.2 std   0.0 std    +0.2 std
    $1            Reverse        -0.2 std   0.0 std    +0.2 std
    $2, left      Forward        -0.2 std -0.15 std    -0.1 std
    $2, left      Reverse        -0.2 std -0.15 std    -0.1 std
    $2, right     Forward         0.0 std  +0.1 std    +0.2 std
    $2, right     Reverse         0.0 std  +0.1 std    +0.2 std
    $5            Forward        -0.2 old   0.0 new    +0.2 old
                               (lt str)   (dk str)    (lt str)
    $5            Reverse        -0.2 old   0.0 new    +0.2 old
                               (lt str)   (dk str)    (lt str)
    $10, left     Forward        -0.2 old  -0.1 new     0.0 old
    $10, left     Reverse         0.0 old  +0.1 new    +0.2 old
    $10, right    Forward        +0.1 old  +0.2 new    +0.3 old
    $10, right    Reverse        -0.2 old -0.15 new    -0.1 old
    $20           Forward        -0.2 old   0.0 new    +0.2 old
    $20           Reverse        -0.2 old   0.0 new    +0.2 old
    $50           Forward        -0.2 std   0.0 std    +0.2 std
    $50           Reverse        -0.2 std   0.0 std    +0.2 std
    $100          Forward        -0.2 std   0.0 std    +0.2 std
    $100          Reverse        -0.2 std   0.0 std    +0.2 std

     TABLE 3
    Sequence   Scanned  Scanned Pattern Scanned Pattern  Master
    Position   Pattern   Modified Once  Modified Twice   Pattern
        1        93           50              -21          161
        2        50           -21             50           100
        3        -21          50              93           171
        4        50           93              65           191
        5        93           65              22           252
        6        65           22              79           403
        7        22           79              136          312
        8        79           136             193          434
        9        136          193             278          90
       10        193          278             164           0
       11        278          164             136          20
       12        164          136             278          444
         .         .            .               .            .
         .         .            .               .            .
         .         .            .               .            .
       52       -490         -518            -447         -1090
       53       -518         -447            -646         -767
       54       -447         -646            -348         -575
       55       -646         -348             -92         -514
       56       -348          -92             -63         -545
       57        -92          -63            -205          -40
       58        -63         -205             605         1665
       59       -205          605            1756         1705
       60        605         1756            1401         1685
       61       1756         1401            1671         2160
       62       1401         1671            2154         2271
       63       1671         2154            *2240        2240
       64       2154         *2210           *2210        2210