WO2004081886A1

WO2004081886A1 - Method and apparatus for processing documents

Info

Publication number: WO2004081886A1
Application number: PCT/GB2004/000993
Authority: WO
Inventors: Antony John Leonard; Timothy Edward Berridge
Original assignee: De La Rue International Limited
Priority date: 2003-03-12
Filing date: 2004-03-11
Publication date: 2004-09-23
Also published as: GB0305674D0

Abstract

Document processing apparatus comprises an input location (2) for receiving a stack of documents at least some of which bear an identifier. A feed system (5, 15, 19, 23) feeds the documents to one or more output locations (105). A store (75) stores the unique identifier of the document in the stack. An identifier reader (50) reads the identifier of each document and a control system (65): i) compares the read identifier with the stored identifier(s); and, ii) if the identifier of a document is the same as the, or one of the, stored identifier, identifying that document as a stack separator.

Description

METHOD AND APPARATUS FOR PROCESSING DOCUMENTS

The invention relates to a method and apparatus for processing documents at least some of which have a, typically unique, identifier provided thereon. Examples of such documents include documents of value including banknotes .

It is a common requirement to process documents, particularly documents of value such as banknotes, in batches. These are placed in an input hopper of a sorting or counting machine and are often fed through the machine continuously without the machine stopping.

In this case, it is usual to use a separator document to mark the beginning and/or end of a batch. The separator at the beginning of a batch is called the header. The separator at the end of the batch is called the trailer. The separators are fed through the machine like normal notes except that when detected and after reading/detecting information contained thereon, they are generally routed to a destination to which reject/suspect notes are routed. This enables rejected or suspicious notes from the identified batch to be contained between headers and trailers or the identifying header and the following header for subsequent examination/inspection. In single output pocket sheet counting machines, the headers or trailers are sent to the single pocket to provide separating means between the batches processed when the sheets are removed from the pocket by the operator. The passage of a separator in both single and multiple output pocket machines can also be used to control the feed process itself, for example to stop when a trailer separator is detected. Monitoring separators is also important to indicate the batches which have been processed for recording purposes and to enable information to be provided about the contents of the batch.

It is further necessary to identify the batches using numbers or alpha characters on the headers. This can be done using a barcode printed on the separator. The barcode needs to be read by the sorter. The reading must be certain and accurate.

Traditionally, as shown for example in US-A-4248528 and US-A-4629311, the batch separator barcode reader has been positioned in the transport of the feeder at some distance from the input hopper. The reader takes the form of a static laser that scans the barcode as the separator moves through the beam. More recently, we have described in O-A-02/26607 locating the reader at the input.

As a batch separator may be fed accidentally with another document that would prevent the recognition of the separator, a further feature is often added to the separator. This feature takes the form of an ear that stands proud of the separator/note. A further optical sensor is sometimes necessary to recognise a pattern on the ear.

The ear sensor is mounted in the transport of the feeder but positioned as near as possible to the input hopper such that a separator may be recognised sufficiently quickly so as to enable the machine to stop feeding before the next document is fed. This is required in some modes of machine operation where the machine is required to stop at the end of each batch of notes. The prior art approach involving the use of separators introduces complexity in the apparatus since this needs to handle the separators themselves which are typically made of a thicker paper or other substrate than the documents, while where such separators are provided with ears, then the transport within the apparatus must be constructed so as to allow the passage of such ears.

In accordance with a first aspect of the present invention, a method of processing documents at least some of which have an identifier provided thereon comprises arranging the documents into a stack; storing the identifier of a document in the stack and storing other data in association with the stored identifier; reviewing serially the documents in the stack with document processing apparatus, the apparatus carrying out at least the following steps : a) reading the, or part of the, identifier, if any, of each document ; b) comparing the read identifier with the stored identifier (s) ; and, c) if the identifier of a document is the same as the, or one of the, stored identifier, identifying that document as a stack separator.

In accordance with a second aspect of the present invention, a method of classifying a stack of documents, at least some of which carry an identifier comprises storing the identifier of a document (the "identification document") in a known position in the stack and storing other data in association with the stored identifier.

In this second aspect, usually the identification document identifier will be stored prior to reviewing the stack. However, this could be done during processing. For example, the document at a known position in the stack, typically the first but other positions within or at the end could be used, could be designated the identification document and its identifier stored automatically by processing apparatus. This aspect is useful when processing a single bundle or stack of documents.

In accordance with a third aspect of the present invention, document processing apparatus comprises an input location for receiving a stack of documents at least some of which bear an identifier; a reviewing system for reviewing the documents; a store for storing the identifier of a document in the stack; an identifier reader for reading the identifiers; and a control system for: i) comparing the, or part of the, read identifier, if any, with the stored identifier (s) ; and, ii) if the identifier of a document is the same as the, or one of the, stored identifier, identifying that document as a stack separator. In contrast to the previous use of separator cards distinct from the documents . being processed, we have realized that it is possible to utilize the identifiers themselves so as to classify particular documents as separators. This then avoids the need for any additional separator cards and the like and allows batches of documents to be processed in conventional sorters and counters including desktop machines as well as machines such as spindle counters in which the documents are processed whilst remaining in the stack. It will be appreciated that it is not necessary to store every identifier in a stack but simply the identifier (s) corresponding to the separator document .

In some embodiments in accordance with the second aspect of the invention, the user arranges for the identifier of the document at a known position in the stack to be stored and with it other data such as the source of the documents, the value of the documents in the stack etc.

In embodiments according to the first and third aspects of the invention, the documents in the stack are processed, for example to check their authenticity and/or to identify the documents such as denomination in the case of banknotes.

As with the use of conventional separators, information can be stored relating to the outcome of the processing procedure for example details of documents which failed various tests such as an authenticity or denomination test, the total value or number of documents in the batch, the value of different denominations within the batch, the fitness/condition of the documents, the date/time of processing, customer value of cheques, operator name, documents scheduled for destruction etc.

Although the invention could be used with a single stack of documents, it is particularly suited for use in connection with one or more further sets of documents.

Thus, the method preferably further comprises arranging one or more further sets of documents into respective stacks; for each stack storing the identifier of a document in a known position in the stack and storing other data in association with the stored identifier; arranging all the stacks into a single multiple stack, and then performing the feeding and processing steps on the multiple stack.

As explained previously, the method can be used with generally conventional sorters and counters and, where these feed documents along a transport path, these may have a single output location or multiple output locations. Other examples of apparatus where the invention can be used include deposit units such as the TCR Twinsafe recycler or the TDU, Teller Deposit Unit, manufactured and sold by De La Rue International Limited. These machines are capable of operating in a similar way to counters and sorters but the notes, once accounted for, are stored within the machine in secure storage, rather than output for the operator to collect. They may have cassettes, roll-storage modules or drop-boxes for storing the notes. It is also feasible that the technique could be used in the field of dispensing.

In order to read the identifier on each document, it is necessary to provide some means for doing so. This could be a purpose designed identifier reader located, for example, to detect identifiers such as serial numbers, on documents while they are at an input location such as at the bottom of a stack in an input hopper. Alternatively, such a reader could be positioned somewhere along the feed path along which documents are fed while they are being processed. Alternatively, where a sensing system is already provided for monitoring the appearance of documents then this can also be utilized to obtain details about the identifier. For example, in the case of a pattern recognition system for determining the identity of documents such as their denomination in the case of banknotes, this could also be used for locating and reading the identifier. The location of the identifier could be preprogrammed in accordance with the identity of the document or an algorithm of known form could be used to locate the identifier from an image of the document.

In some cases, identifiers will only be provided on some of the documents although in cases such as the processing of banknotes or cheques there will typically be an identifier on each document. Furthermore, although in many cases the identifier will be unique as in the case of a banknote serial number, this is not essential. Typically, each document in the stack will have an identifier which is different from all other identifiers of documents in the same stack. However, it is conceivable that part of the identifier may relate to the nature of the document, for example its denomination, while the rest of the identifier, although unique to that particular denomination, is not, in itself, unique. In this situation, it would not be necessary to review the entire identifier but only part of the identifier to the extent that that part is unique within the stack. The reviewing of identifiers typically comprises reading or sensing the identifier although, as explained above, it may not be necessary to "read" the entire identifier. Also, if some characters cannot be identified from the gathered data then techniques such as those described in US-A-6510238 could be used.

Typically, the identifier comprises an alphanumeric sequence but^' other forms of identifier are envisaged. Thus, the identifier may be stored within an integrated circuit such as a chip located within the document. In other cases, identifiers could be provided by luminescent fibres (randomly distributed during the formation of the paper substrate) , RFID, a magnetic code stored in an ink or thread, a barcode, MICR, etc.

If the "carrier" of the identifier is a programmable device then the document can be configured as a separator prior to loading the documents into the apparatus and, perhaps, de-configured after the documents have been processed. Further than this, the programmable nature of the device enables information to be put into a trailing "separator" after the notes have been processed. This would enable information regarding the batch to be transported with the documents themselves, eliminating the security risks that might be associated with sending this data over a network. Thus, in this case, the processed information is actually stored within the "separator" document itself. Alternatively, or in addition, that information can be stored on a separate database provided locally or remotely to the processing apparatus.

Some examples of methods and apparatus according to the invention will now be described with reference to the accompanying drawings, in which: - Figure 1 is a schematic diagram showing the primary transport components of a first example of a banknote counter;

Figure 2 is a schematic block diagram of an infrared head; Figure 3 illustrates schematically the appearance of the relationship between an infra-red head and a bankote;

Figure 4 is a block diagram of the control system;

Figure 5 is a flow diagram illustrating operation of the s stem; Figure 6 is a flow diagram illustrating how serial numbers are processed;

Figure 7 illustrates part of the contents of a batch record store;

Figure 8 is a view similar to Figure 1 but of a further example; and

Figure 9 is a schematic block diagram of a further example of banknote sorter.

Figure 1 illustrates a banknote counter 100 having an input hopper 2 mounted beneath an inlet opening 3 in an enclosure 1 which comprises upper and lower parts la, lb normally screwed together. Contained within the enclosure

1 is an internal chassis assembly (not shown for clarity) which itself has side members between which the sheet feeding and transport components to be described herein, are mounted. Two conventional feed wheels 5 are non-rotatably mounted on a shaft 7, which is rotatably mounted to the chassis assembly, and have radially outwardly projecting bosses 6 which, as the feed wheels rotate, periodically protrude through slots in the base of the hopper 2.

A pair of stripper wheels 15 are non-rotatably mounted on a drive shaft 16 which is rotatably mounted in the chassis assembly. Each stripper wheel 15 has an insert 17 of rubber in its peripheral surface. Shaft 16 is driven clockwise by a motor 200 (Figure 4) to feed notes individually from the bottom of a stack of notes placed in the hopper 2.

Transversely in alignment with, and driven from the circumferential peripheral surface of the stripper wheels 15, are pressure rollers 30 which are rotatably mounted on shafts 31 spring-biased towards the stripper wheels 15. Downstream of the wheels 15 is a pair of transport rollers 19 non-rotatably mounted on a shaft 20 rotatably mounted in the chassis assembly. Each roller 19 has a cylindrical form with a constant radius along its axis. Shaft 20 is driven clockwise from a second motor (not shown) to transport the note in the transport arrangement, in conjunction with pairs of pinch rollers 21,23 into stacking wheels 27 and hence output hopper 105. Pinch rollers 21, rotatably mounted on shafts 22 spring based towards the transport rollers 19, transversely align with rollers 19 and are driven by the peripheral surface of the rollers 19. The rollers 23, rotatably mounted on shafts 24 are in alignment with the transport rollers 19, and are essentially caused to rotate by the note passing between the adjacent peripheral surfaces of the rollers 19 and 23. Situated between the pressure rollers 30 and pinch rollers 21 are separator roller pair 25, non-rotatably mounted on shaft 26 adjustably fixed to a top moulding assembly 32, having a circumferential peripheral surface which is nominally in alignment with the peripheral circumferential surface of, but transversely separated from, the stripper wheels 15. Also forming part of the top moulding assembly 32, is a curved guide surface 8 extending partly around the circumference of the rollers 15, 19 which, when the top moulding is lifted allows the operator access to the note feed and transport path so that a note jam can be cleared. A surface 37 provides note guiding from the end of the curved guide surface 8 to the conventional stacking wheels 27.

The drive shaft 16 is continuously driven, and this, via a belt and pulley arrangement from shaft 16, causes the auxiliary drive shaft 7 rotating the feed wheel 5 also to be driven. Drive shaft 20, rotating the transport rollers 19, is driven by the other drive motor. A further pulley and belt arrangement (not shown) between shaft 20 and shaft 28, on which the stacking wheels 27 are non-rotatably mounted, provides the drive to the stacking wheels 27.

The guide plate 8 extends as a continuation of the base of the hopper 2 towards the nips formed between the transport rollers 19 and the rollers 23.

A sensor head 50 is mounted downstream of the rollers 21 and includes a linear array of light emitting diodes 51

(Figure 2) and a linear array of, typically 144, photodiodes 52. In particular, the linear array 51 typically comprises 92 LEDs extending collectively a length of about 9" (23cms) while the linear array of photodiodes 52 extends a comparable length (Figure 3) . The LEDs typically emit visible, e.g. white, light but in addition or alternatively at least some LEDs could emit infra-red or UV light. The head 50 is located opposite to a reference black surface forming part of the note guide as illustrated at 53. It will be appreciated that the head 50 and surface 53 are laterally offset from the rollers 19. As a banknote 55 is conveyed by the transport system, it will pass beneath the head 50 and be irradiated by the light emitting diodes 51. This radiation is reflected by the banknote in dependence upon the pattern on the banknote and, in the case of IR or UV light, the materials on or in the banknote, the reflected or emitted radiation being detected by the photodiodes 52. The output signals from the photodiodes 52 are regularly sampled so as to generate a set of intensity values for each region or pixel of the banknote 55, this information being stored in a memory 60 (Figure 4) .

The head 50 is connected to a microprocessor 65 which is also connected to the memory 60. This is described in more detail in WO-A-00/26861 incorporated herein by reference and so will not be described in detail . The microprocessor 65 is programmed to identify the denomination of the banknote and also its authenticity. In one example, the denomination and authenticity are determined separately. For example, certain regions of the banknote will be reviewed for the purposes of denomination determination while other regions will be reviewed for purposes of authenticity. However, in other applications, particularly if the whole banknote is considered, then a single process can be used to establish both denomination and authenticity. As far as denomination is concerned, the processor 65 compares all or part of the test pattern stored in the memory 60 with a plurality of reference or prestored patterns in a memory 70. These prestored patterns will have been generated in any conventional manner from a set of genuine banknotes.

Thus, as set out in Figure 5, once the test pattern has been obtained and stored (step 80) , it is compared by the processor 65 with each prestored pattern (step 85) . These prestored patterns may define a single banknote in one or more of its possible orientations or a plurality of banknotes also in one or more of their orientations. The processor 65 then selects the most similar prestored pattern (step 90) and determines whether the degree of similarity exceeds a first threshold (step 95) . If it does not, then the system determines that the banknote is unrecognisable (step 110) . Otherwise, the processor 65 determines whether the difference between the degrees of similarity of the test pattern with the two most similar prestored patterns exceeds a second threshold (step 120) so as to establish whether or not there is a clear match. If there is then the banknote is identified with the most similar prestored pattern (step 125) while otherwise the banknote is considered to be not identified. In that event a count, of value and/or number of notes, is incremented.

The pattern matching technique used in step 85 can be of any conventional type, a preferred approach being described in WO-A-00/26861. Other examples are described in US-A-4179685 and EP-A-088309 .

As mentioned above, the processor 65 could carry out a separate authenticity determination by looking at a particular region of the banknote to see whether the infra- red reflectance, or UV response, satisfies a predetermined condition or alternatively this could be inherent in the pattern recognition process carried out to determine denomination. In addition, other authenticity properties such as magnetics could be tested if a suitable detector is provided. In any event, if the processor 65 is satisfied that the banknote is authentic and its denomination has been identified it will then control the subsequent processing and handling of the banknote. In this example, the banknote will be allowed to continue on to the output hopper 105 and further banknotes will be fed from the input hopper 2.

If the processor 65 determines that the banknote is not authentic or cannot be identified then the motor 200 may be stopped to prevent further banknotes from being fed to the output hopper and a suitable error message will be displayed. The operator then has a number of options. Firstly the operator could substitute a known-good note and carry on, assuming that there is a method of continuing, while maintaining the count (s) . Or the operator could accept the note, indicating its denomination, if this is the reason that the machine has stopped, and the machine is then reactivated to continue counting. Or the note could be removed, perhaps with the operator indicating that this has been done, and the note would be excluded from the batch process data or count.

In addition to checking the authenticity and checking the denomination of the banknotes, the system described is also used to identify banknotes which have previously been nominated as separators .

In order to handle batches of banknotes, the operator first arranges each batch of banknotes into a bundle (step 500, Figure 6) and then manually reads the serial number of either the leading or trailing banknote of that bundle. This serial number is then input (step 502) by the operator into a store 75 coupled with the processor 65 using a keyboard or other input device (not shown) . In other examples, a group of separator identifiers could be prestored and in all cases the or each identifier could be downloaded to the store from a remote source, e.g. via the Internet or dedicated line, rather than being manually input locally. In addition, the "manual" input could involve feeding just the separator document through the apparatus in a set-up mode.

Part of the contents of the store 75 is shown in Figure 7. Here the first line indicates the batch number 1 and the serial number of the separator document which has been identified and input by the operator in step 502 namely "1234567" .

In step 502, the operator also inputs other information about the bundle which, in this example, comprises the source of the banknotes, namely "A BANK" which is stored in association with the separator document serial number. Other information which could be input includes the deposit owner (bank/retail store etc.), expected quantity of documents, and expected value of the bundle .

The bundles are then consolidated into a single stack (step 504) and loaded into the input hopper 2 of the counter machine (step 506) of Figure 1.

The note counting apparatus shown in Figure 1 is then activated (step 508) to process the documents one by one from the input hopper 2. As well as operating to detect denomination and authenticity, the information from the head 50 is also used by the processor 65 to locate and identify the serial number on each banknote. This serial number is compared with the separator serial number for that batch and the processor 65 notes when a match is found. Assuming that this banknote is the lowermost in the hopper 2, the processor 65 then knows that all succeeding notes which it processes should be associated with that separator.

As processing continues, the processor maintains a running total of the values of each denomination which is detected. In this example, it is assumed that the batch is made up of a mixture of Bank of England £5 and £10 notes. If a banknote is found to fail an authenticity or denomination test then its serial number is noted and stored in the store 75 by the processor 65 (step 506) . This is shown in the fourth cqlumn of the table in Figure 7. As mentioned above, the apparatus will stop under these conditions allowing the operator to take one of a number of actions. In this situation, the operator can have further confidence that he is removing the correct note if the processor 65 arranges for the serial number of the note concerned to be displayed on a display such as a monitor (not shown) . The operator will then press a continue button which allows the process to continue with the existing counts until the batch has been fully processed. In the example described, it will be seen from Figure 7 that two banknotes were found to fail tests and their serial numbers have been identified. The processor 65 then stores the totals of each denomination of note, in this case £100 of £5 notes and £1000 of £10 notes and also stores a grand total for the batch of £1100 (step 508) . This information can the be output onto a computer or displayed in a conventional manner (step 510) .

Typically, and in this example, more than one bundle is provided in the input hopper 2 at one time. In that situation, in step 502, the operator not only identifies the separator banknote of the first batch but also the separator banknote of succeeding batches. In this case, a second batch has been placed in the input hopper 2 and the operator has identified the separator banknote (which is the first banknote to be processed in the next batch) as "3851000". He also indicates that the source is "B BANK".

For convenience, the processor 65 arranges to stop processing as soon as it detects the next separator at the beginning of batch number 2. This enables the operator to remove the preceding batch number 1 from the output hopper before the second batch is stacked. However, in other examples, the batches could be fully stacked together in the output hopper and then removed and separated by the operator later.

Processing of the second batch (step 512) continues in the same way as in the first batch and in this case a single banknote with the number 2841567 has been identified as failing either an authenticity or denomination test. All the banknotes in the batch have a £50 denomination so that the total for denomination in the grand total is the same at £10000.

The counter 100 shown in Figure 1 has a single output hopper 105. The invention is also applicable, however, to counters/sorters having multiple output hoppers and Figure 8 illustrates such an example with two output hoppers. The Figure 8 counter 300 has an input hopper 401 having a base

402 with an aperture 403, through which a high friction portion 404 of a nudger wheel 405 can project. The base 402 optionally has a second aperture 406 in alignment with a serial number reader 407 for reading note serial numbers. Banknotes are supported in a stack on the base 402 against a front wall 426, and are fed intermittently by rotation of the nudger roller 405 into a nip 408, between a high friction feed roller 409 and a separate, counter rotating roller 410. The nudger 405 and roller 409 are driven by a motor 200 (not shown) . The documents pass through pinch rollers 411,412 into a pattern detection region 413 in which a sensor of a transmission pattern recognition system 414A,414B (414B indicating a LED array similar to the array 51 and 414A indicating an array of photodiodes similar to the array 52) scans the banknote as it is fed and passes information back to a microprocessor of the system 414A (not shown) . Each banknote is then fed through pinch rollers 416,417 onto a drive belt 418 which conveys the banknote around various rollers 419 to a diverter 420. At least one of the rollers is driven by a motor (not shown) . The position of a diverter 420 is controlled by the microprocessor of the system 414A, so that banknotes are guided either towards an output pocket 421, where they are stacked using a rotating stacking wheel 422 in a conventional manner, or to a reject bin 423.

As can be seen, the banknotes are stacked on the base 402 and are urged forward against the front wall 426. A small gap 427 is provided at the base of the front wall, through which individual banknotes and separators can be nudged .

The pattern recognition system 414A,414B operates on the detected image data in an exactly similar way to the pattern recognition system of the previous example, for example as described in WO-A-00/26861. In this case, however, instead of stopping the transport when an unsatisfactory condition is determined such as a double note feed or the like, the diverter 420 is operated so that the unacceptable notes are fed to the reject bin 43. In another alternative (not shown) , in any of these examples bi-colour LEDs or sets of alternately activatable red and i.r. LEDs could be used to obtain visible and i.r. pattern data for subsequent processing by suitably switching activation of the LEDs as the note is scanned. In all the examples, notes are typically processed at transport speeds in excess of 800 notes per minute, usually in excess of 1200 notes per minute.

In contrast to the Figure 1 example, in this case the serial number of each banknote is obtained by the reader 407 and then utilized by the microprocessor in the same way as the processor 65 of the first example.

Figure 9 illustrates a further example of a multi- output pocket banknote sorter. In this example, banknotes 600 are provided to an input hopper from where they are fed by a transport system (not shown) past a set of detectors 602 for detecting one or more of size, magnetic pattern, magnetic thread, IR pattern, UV bright , limpness, holes and tears, tape etc. and then past an imaging detector system (IDS) 604. The IDS 604 includes a line scan camera and power supply, a light source, a processor etc. The IDS 604 can be arranged to detect denomination, authenticity and the like. In addition, it can be used to detect the serial number of each banknote . An example of a conventional IDS which can be used with this embodiment is the IDS manufactured and sold by CSI of Dallas, Texas, USA, in their CPS range.

Following inspection, the banknotes are then sorted into appropriate destination pockets 506 in a conventional manner.

A pair of monitors 608, 610 are provided for enabling a user to monitor operation of the sorter and the IDS respectively.

It will be understood in all these examples that if serial numbers only appear on one surface of the banknotes, the appropriate surface needs to be arranged so as to face the corresponding reader. Alternatively, readers can be provided along the transport on both sides so that the serial number can be read irrespective of the orientation of the banknote .

It should also be noted that although the process has been described in connection with banknotes, it is usable with any type of document which includes a unique serial number .

Claims

1. A method of processing documents at least some of which have an identifier provided thereon, the method comprising arranging the documents into a stack; storing the identifier of a document in the stack and storing other data in association with the stored identifier; reviewing serially the documents in the stack with document processing apparatus, the apparatus carrying out at least the following steps: a) reading the, or part of the, identifier, if any, of each document ; b) comparing the read identifier with the stored identifier (s) ; and, c) if the identifier of a document is the same as the, or one of the, stored identifier, identifying that document as a stack separator.

2. A method according to claim 1, further comprising recording information obtained by the processing apparatus for one or more documents in the stack, in association with the stored identifier.

3. A method according to claim 1 or claim 2, wherein the document processing apparatus is adapted to determine the authenticity of the documents.

4. A method according to claim 3, when dependent on claim 2, wherein information relating to the authenticity is recorded in association with the stored identifier.

5. A method according to claim 4, wherein the unique identifier of any documents failing to be authenticated is recorded in association with the stored identifier.

6. A method according to any of the preceding claims, wherein the processing apparatus is adapted to determine the value of the documents.

7. A method according to claim 6, wherein information relating to the value of the documents is stored in association with the stored identifier.

8. A method according to claim 6 or claim 7, wherein the identifier of any documents whose value cannot be determined is stored in association with the stored identifier.

9. A method according to any of the preceding claims, wherein the number of documents in the stack is stored in association with the stored identifier.

10. A method according to any of the preceding claims, wherein the documents are all documents of value such as banknotes.

11. A method according to any of the preceding claims, wherein the data which is stored in association with the stored identifier includes one or more of the source of the documents, the total value or number of the documents in the stack, the total value of each type of document, authenticity characteristics of the documents, the fitness/condition of the documents, the date/time of processing, customer value of cheques, operator name, documents scheduled for destruction, etc.

12. A method according to any of the preceding claims, wherein the stack separator document is at the top of the

SC9.CK- •

13. A method according to any of claims 1 to 11, wherein the stack separator document is at the bottom of the stack.

14. A method according to any of the preceding claims, wherein each document in the stack has an identifier which is different from all other identifiers of documents in the stack.

15. A method according to any of the preceding claims, wherein each identifier is one of alphanumeric data, IC stored data, luminescent fibres, RFID, a magnetic code stored in an ink or threads, a barcode, MICR, etc.

16. A method according to any of the preceding claims, wherein the reviewing step comprises feeding the documents serially through the document processing apparatus.

17. A method according to claim 16, wherein the processing apparatus feeds the documents from an input location to a single output location.

18. A method according to claim 16, wherein the processing apparatus feeds the documents from an input location to one of a number of output locations.

19. A method according to claim 18, wherein documents failing to pass a test carried out by the processing apparatus are fed to a reject location.

20. A method according to claim 18 or claim 19, when dependent on claim 6, wherein documents of different value are fed to corresponding output locations.

21. A method according to any of claims 16 to 20, wherein the identifier of a document is read while the document is at the input location.

22. A method according to any of claims 16 to 20, wherein the identifier is read while the documents are fed through the document processing apparatus.

23. A method according to any of the preceding claims, further comprising arranging one or more further sets of documents into respective stacks; for each stack storing the identifier of a document in the stack and storing other data in association with the stored identifier; arranging all the stacks into a single multiple stack, and then performing the reviewing and processing steps on the multiple stack.

24. A method according to any of the preceding claims, wherein the documents comprise documents of value such as banknotes .

25. A method according to any of the preceding claims, wherein the documents carry unique serial numbers.

26. A method of classifying a stack of documents, at least some carrying an identifier, the method comprising storing the identifier of a document in a known position in the stack and storing other data in association with the stored identifier.

27. A method according to claim 26, wherein the data which is stored in association with the stored identifier includes one or more of the source of the documents, the total value or number of the documents in the stack, the total value of each type of document, authenticity characteristics of the documents, the fitness/condition of the documents, the date/time of processing, customer value of cheques, operator name, documents scheduled for destruction, etc.

28. Document processing apparatus comprising an input location for receiving a stack of documents at least some of which bear an identifier; a reviewing system for reviewing the documents; a store for storing the identifier of a document in the stack; an identifier reader for reading the identifiers; and a control system for: i) comparing the, or part of the, read identifier, if any, with the stored identifier (s) ; and, ii) if the identifier of a document is the same as the, or one of the, stored identifier, identifying that document as a stack separator.

29. Apparatus according to claim 28, wherein the control system is adapted to record in the store, information obtained by the processing apparatus for one or more documents in the stack, in association with the stored identifier.

30. Apparatus according to claim 28 or claim 29, further comprising a system for determining the authenticity of the documents .

31. Apparatus according to claim 30, when dependent on claim 29, wherein the control system is adapted to record in the store information relating to the authenticity, in association with the stored identifier.

32. Apparatus according to claim 31, wherein the control system is adapted to record in the store the identifier of any documents failing to be authenticated, in association with the stored identifier.

33. Apparatus according to any of claims 28 to 32, wherein the processing apparatus is adapted to determine the value of the documents.

34. Apparatus according to claim 33, wherein the control system is adapted to record in the store information relating to the value of the documents, in association with the stored identifier.

35. Apparatus according to claim 33 or claim 34, wherein the control system is adapted to record in the store the identifier of any documents whose value cannot be determined in association with the stored identifier.

36. Apparatus according to any of claims 28 to 35, wherein the control system is adapted to record in the store the number of documents in the stack, in association with the stored identifier.

37. Apparatus according to any of claims 28 to 36, wherein the data which is stored in association with the stored identifier includes one or more of the source of the documents, the total value or number of the documents in the stack, the total value of each type of document, authenticity characteristics of the documents, the fitness/condition of the documents, the date/time of processing, customer value of cheques, operator name, documents scheduled for destruction, etc.

38. Apparatus according to any of claims 28 to 37, adapted to process one or more further sets of documents in respective stacks; wherein the control system is adapted to record in the store for each stack the identifier of a document in the stack and other data in association with the stored identifier.

39. Apparatus according to any of claims 28 to 38, wherein the reviewing system comprises a feed system for feeding documents from an input location to one or more output locations .

40. Apparatus according to claims 39, comprising an input location and a single output location.

41. Apparatus according to claim 39, comprising an input location and a plurality of output locations.

42. Apparatus according to claim 41, wherein the control system is adapted to cause documents failing to pass a test carried out by the processing apparatus to be fed to a reject location.

43. A method according to claim 41 or claim 42, wherein documents of different value are fed to corresponding output locations .

44. Apparatus according to any of claims 40 to 43, further comprising a sensor located adjacent the input location so that the identifier of a document is read while the document is at the input location.

45. Apparatus according to any of claims 28 to 43, further comprising a sensor located along the document feed passage so that the identifier is read while the documents are fed through the document processing apparatus .