JPH1153603A - Document identification device and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To identify paper money of various denominations. SOLUTION: In identifying paper moneys 17 of various denominations, the paper moneys 17 are received at an entrance place 12 in a piled-up state and the paper moneys 17 are sent to an exit place 20 one by one by a transfer mechanism 16. During this time, the paper moneys 17 are irradiated by an irradiation means 22 and scanned along the narrow width side of the paper moneys 17 by the detector 26 of an identification unit 18. A scanned result and possessed data are compared, and when it is found that the paper money 17 is not one of any denomination, a flag is put out and the transfer mechanism 16 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates generally to currency identification. More particularly, the present invention relates to a method and apparatus for automatically identifying and counting currencies of various denominations using the characteristics of light reflection of indicia printed on the currency.

[0002]

2. Description of the Related Art Various techniques and devices have been used to satisfy the needs of automatic currency bill handling systems. The earliest in the art are able to handle only certain types of banknotes, such as dollar bills of a specific face value,
A system that repels all other types of banknotes. The most sophisticated are complex systems that can identify, identify and automatically count a large number of denominations.

Banknote identification systems typically use either magnetic or optical detection to distinguish between various denominations. Magnetic detection uses a magnetic sensor, usually a ferrite core-based sensor, to detect the presence or absence of magnetic ink in the printed indicia on the banknote and adds analog or digital processing Later, it is based on using the detected magnetic signal as a basis for banknote identification. On the other hand, more commonly used optical detection techniques are based on detecting and analyzing changes in the reflection or transmission characteristics of light that occur when a banknote is illuminated and scanned with a focused strip of light. I have. Subsequent banknote identification compares the detected optical features to pre-stored parameters for various denominations, taking into account the appropriate error in the difference in reflection between individual denominations at each denomination. It is based on

[0004] A major problem in implementing an automatic bill identification system is the criteria used to properly configure the feature pattern for a particular denomination, and identifying bills under close scrutiny. The time it takes to analyze the test data and compare it with a predetermined pattern,
The best compromise between the speed of mechanically feeding and scanning a continuous banknote. Even if a microprocessor is used to process test data obtained from banknote scanning, the process of obtaining a sample and comparing the test data to stored parameters to identify the denomination of the banknote has a finite amount. Time is needed. Many of the currently available optical scanning systems are used to obtain a large number of reflection data samples when a bill is scanned by a scanning head and subsequently compare these data with corresponding stored parameters to determine the face value of the bill. Use complex algorithms to identify monetary values. Conventional systems require a relatively large number of optical samples per scan of a bill to fully discriminate between denominations, especially denominations where the reflection pattern is not significantly distinguishable. The use of a large number of data samples slows down the scanning of incoming bills, and more importantly,
Correspondingly, the data processing takes a long time in accordance with the identification algorithm. Processing time is further increased if the system is also adapted to count the identified denominations. This limits the speed at which bills are sorted and counted. This means that the real-time processing must have analyzed the data scanned for the bill, and that the bill is placed across the scan head and that the bill is at a particular denomination before being scanned by the scan head. Because it must be identified and counted as belonging to

[0005] The main problems associated with conventional systems are:
Such a system is constrained to scan the banknote along its long dimensions in order to obtain the large number of reflection samples required to accurately identify the banknote. Similarly, scanning has some inherent disadvantages. These disadvantages include the disadvantage that a long transport path is required to feed the bill longitudinally across the scanning head, and the long transport path, as well as ensuring uniform and non-overlapping alignment of the bill. It has the disadvantage of adding the mechanical complexity associated with the means associated with the detection surface of the scanning head.

[0006] In conclusion, systems that can accurately identify banknotes are costly, mechanically bulky and complex, and generally cannot perform both banknote identification and counting at high speed and with high accuracy.

[0007]

SUMMARY OF THE INVENTION The main object of the present invention is to:
SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved method and apparatus for identifying and counting currency notes having a plurality of denominations.

It is another object of the present invention to provide an improved method and apparatus of the kind described which is capable of efficiently distinguishing and counting between several denominations of banknotes at high speed and with high accuracy. is there.

It is a related object of the present invention to provide an improved bill identification and counting device that is compact, economical, and not complex in construction and operation.

[0010]

SUMMARY OF THE INVENTION Briefly, according to the present invention, the above-listed objects have been achieved by an improved optical detection correlation technique employed in bill counting and face value discrimination. You. This technique is based on optically detecting the reflection characteristics of a banknote obtained by illuminating and scanning the banknote along its narrow dimension and about the central section of the banknote. Light reflected from the bill as the bill is optically scanned is detected and used as an analog signal to represent the "black" and "white" changes contained in the pattern or indicia printed on the bill surface.

[0011] A series of such reflected signals is generated at a predetermined sample point as the bill moves across the illuminated strip with the narrow dimension of the bill parallel to the bill transport direction. It is obtained by sampling and digitally processing the reflected light under the control of a microprocessor. Accordingly, a predetermined number of reflection samples can be obtained over the narrow width of the bill. The data sample obtained for each scan of the banknote is digitally processed, including a normalization process that does not emphasize variations due to changes in printed patterns or "shading" of the indicia present on the surface of the banknote being scanned. Is added. The normalized reflection data represents a very unique feature pattern for a given denomination and provides sufficient discriminating features between these feature patterns to accurately distinguish feature patterns for various denominations. .

By using the method described above, an "original" for each denomination of the bill to be detected
That is, a series of master feature patterns are created and stored using "new" banknotes. According to a preferred embodiment,
Four feature patterns are created for each detectable denomination and stored in system memory. The stored patterns correspond to optical scanning performed on the "front" and "back" sides of the banknote along the "forward" and "reverse" directions with respect to the pattern printed on the banknote. Preferably,
The method and apparatus for identifying and counting banknotes of the present invention comprises seven different denominations of US currency: $ 1, $ 2,
$ 5, $ 10, $ 20, $ 50, and 1
$ 00 is to be identified. Thus, a master set of 28 different feature patterns is stored in system memory for subsequent correlation purposes.

According to the correlation technique of the present invention, the pattern created by scanning the bill under test and processing the sampled data is compared with each of the 28 pre-stored feature patterns for each comparison. Then, for the pattern under comparison, a correlation number is generated that indicates the degree of similarity between the corresponding one of the plurality of data samples. The identification of the denomination is based on an indication that the scanned bill belongs to the denomination corresponding to the stored feature pattern determined to have the highest correlation number by pattern comparison. The likelihood that the denomination of the scanned bill has been characterized and lost after the comparison of the feature patterns is "yes (posi).
tive) a bi-level threshold of correlation that must be satisfied in order for a call to be made.
threshold) is significantly reduced.

[0014] In essence, the present invention relates to a method in which a banknote is scanned multiple times along its "front" or "reverse" direction, regardless of whether its "front" or "back" surface is scanned. To provide an improved optical detection correlation technique for unambiguously identifying which of the various denominations. The invention is particularly adapted to be implemented in a system programmed to track each of the identified denominations so as to conveniently provide a total of the identified bills at the end of the scanning operation. I have.

Further, according to the present invention, there is disclosed a bill detection and counting device adapted for use with the novel detection and correlation technique outlined above. This device accepts banknotes to be counted and converts the banknotes for their narrow dimensions.
It has a curved transfer path for transferring onto a stacking station where bills detected and counted across a scanning head located downstream of the curved path are collected. The scanning head operates in conjunction with the optical encoder.
The optical encoder begins capturing a predetermined number of reflected data samples as the bill (and thus the indicia or pattern printed on the bill) moves across a coherent strip of light focused below the scan head. It is supposed to.

The scanning head uses a row of light emitting diodes to focus a coherent strip of light of a predetermined dimension having a normalized distribution of light intensity over the illuminated area. These light emitting diodes are arranged at an angle and focus the desired strip of light onto the narrow dimension of the banknote, which is laid flat across the scanning surface of the scanning head. A photoelectric detector located above the illuminated strip detects light reflected upward from the bill. The photoelectric detector is controlled by an optical encoder to obtain the desired reflected sample.

The start of sampling is based on the change in the reflection value that occurs when the outer edge of the pattern printed on the banknote is encountered relative to the reflection value obtained at the edge of the banknote without any printing. According to a feature of the invention, at least two illuminated strips of different dimensions are used for scanning purposes. Initially, a narrow strip was used to detect the starting point of the printed pattern on the note, which was typically marked to mark the starting point of the printed pattern on the note. A thin border line (border line) surrounding the pattern is identified. For the remainder of the narrow scan following detection of the border lines of the printed pattern, a substantially wide strip of light is used to collect a predetermined number of samples for the scan of the banknote. The subsequent comparative correlation procedure for creating and storing a feature pattern using an "original" note, and sorting the scanned note as belonging to one of several predetermined denominations, comprises: It is based on the detection correlation technique described above.

Although there is room for implementation of the present invention in various modifications and variations, particular embodiments thereof are shown by way of example and described in detail below. However, this is not intended to limit the invention to the particular embodiments disclosed, which, on the contrary, are intended to cover all modifications within the spirit and scope of the invention as defined by the appended claims. , Equivalents and modifications.

[0019]

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 1, there is shown a functional block diagram illustrating an optical detection and correlation system according to the present invention. The system 10 has a bill receiving station 12 for placing a stack of bills that need to be verified and calculated. The accepted bills are subjected to the action of a bill separation station 14 which functions to remove, i.e. separate, one bill at a time, and are then relayed by a bill transport mechanism 16 according to a pre-determined transport path, Across the optical scanning head 18, the bill value of the bill is scanned, verified and calculated at the optical scanning head 18. The scanned bills are then transported to a bill stacking station 20, where the bills that have undergone such processing are stacked at this station 20 for subsequent removal.

The optical scanning head 18 directs a coherent light beam downwardly onto the bill transport path so as to illuminate a substantially rectangular light strip 24 when the bill 17 is positioned on the transport path below the scan head 18. It has at least one light source 22. The light reflected by the irradiated strip 24 is detected by a photoelectric detector 26 arranged right above the strip. The analog output of the photoelectric detector 26 is converted to a digital signal by an analog-to-digital converter (ADC) unit 28, and the output of this unit is input to a central processing unit (CPU) 30 as a digital input.

According to a feature of the present invention, the bill transfer path is configured such that the transfer mechanism 16 moves the bill with the narrow dimension "W" of the bill parallel to the transfer path and the scanning direction. I have. Thus, the bill 17 is moved on the transport path by the scanning head 1.
As moving at 8, the coherent light strip 24 effectively scans the bill across the narrow dimension "W" of the bill. Preferably, the transport path is configured such that the bill 17 is scanned about its central section along its narrow dimension, as best shown in FIG.

The scanning head 18 detects the light reflected from the bill as it moves across the illuminated light strip 24 and provides an analog representation of the change in the light thus reflected, which is indicated by the display. Indicates changes in "black" and "white" contained in a pattern or mark printed on the surface of a bill. The change in light reflected by scanning the narrow dimension of the bill serves as a measure to identify with high accuracy among a plurality of denominations programmed to be handled by the system of the present invention.

A series of such detected reflected signals are obtained over a narrow dimension of the banknote or over a selected segment of the banknote, and the resulting analog signal is digitized under the control of the CPU 30, Generate digital reflection data samples of The data samples are then digitized. This processing includes processing of the sample data to improve the correlation, and a normalization routine for smoothing the fluctuation due to the change in the “shading” of the print pattern existing on the surface of the bill. The normalized reflection data digitized in this way exhibits a very unique feature pattern for a given denomination, and as described in detail below, there is sufficient inter-feature pattern for different denominations. Give a distinguishing feature.

In order to ensure strict correspondence between the reflection samples obtained by scanning the narrow dimension of successive banknotes, preferably the start of the reflection sampling process is C
It is controlled by the optical encoder 32 through the PU 30. The optical encoder is associated with the bill transport mechanism 16 and tracks the physical movement of the bill 17 across the scan head 18 in detail. More specifically, the optical encoder 32 is associated with a rotational movement of a drive motor that generates a movement applied to the bill as the bill is relayed along the transport path. Furthermore,
Particularly when the bill is scanned by the scanning head 18, a positive contact is maintained between the bill and the transport path. In such a situation, the optical encoder can closely track the movement of the bill with respect to the light strip generated by the scanning head by monitoring the rotational movement of the drive motor.

The output of the photoelectric detector 26 is monitored by the CPU 30 to first detect the presence of the bill under the scanning head, and then to detect the starting point of the printed pattern on the bill indicated by the thin border line 17A. The border line 17A surrounds the print on the banknote. Once the borderline 17A is detected, the banknote 17 moves across the scanning head 18 and, when scanned along its narrow dimension, controls the timing and number of reflected samples obtained from the output of the photoelectric detector 26. An optical encoder is used to do this.

The detection of the border line constitutes an important step and realizes an improvement in the identification efficiency. This is because the border line serves as an absolute reference point for starting sampling. When trying to use the edge of a bill as a reference point, there may be a relative displacement of the sampling points. This is because a relatively large tolerance is allowed during printing and cutting of the banknote, so that the distance from the edge to the border line differs depending on the banknote. As a result, it is difficult to ensure a direct correspondence between successive sample points of banknotes, which has an adverse effect on identification efficiency.

The use of an optical encoder to control the sampling process with respect to the physical movement of banknotes across the scan head can be used to detect border lines following a predetermined delay prior to the start of the sample. It is also advantageous in that it can be done. The encoder delay can be adjusted so that the bill is scanned across only the segments along the narrow dimension of the bill that contain the most discriminating prints for different denominations.

For example, in the case of US currency, when scanning across the narrow central section of the bill, about 5.
The 08 cm (about 2 inch) portion is adapted to provide sufficient data based on the correlation technique of the present invention to distinguish between various US currency denominations. Thus, an optical encoder can be used to control the scanning process, so that reflected samples are obtained over a set period of time and only after a predetermined period of time from the detection of the borderline, thereby scanning the bill. Limited to the desired central portion of the narrow dimension.

The optical detection correlation technique uses the process described above to generate a series of master feature patterns using "new" or "original" banknotes for each denomination of the currency to be detected. Based on According to a preferred embodiment, four feature patterns are generated and stored for each detectable denomination in a system memory, preferably in the form of an EEPROM (Electrically Erasable Read Only Memory) 34 (see FIG. 1). Is done. The characteristic pattern of each bill is optically scanned, i.e., performed on the "front" and "back" sides of the bill, along the "forward" and "reverse" directions with respect to the pattern printed on the bill. Generated corresponding to the process of obtaining a predetermined number of reflection samples taken.

In applying the technology of the present invention to US currency,
For example, a feature pattern may be created to generate seven different face values of US currency: $ 1, $ 2, $ 5,
Dollars, $ 20, $ 50, and $ 100 are stored. Therefore, a master set of 28 different feature patterns is stored in system memory for subsequent correlation purposes. Once the master feature pattern is stored, the pattern generated by scanning the banknotes under test is stored in 28 pre-stored master patterns and CPs.
A comparison is made at U30, and a correlation number is generated for each comparison that indicates the degree of correlation, i.e., the similarity between a corresponding one of the plurality of data samples for the compared pattern.

The CPU 30 is programmed to confirm the face value of the scanned banknote, since it corresponds to the stored characteristic pattern found to have the highest correlation number obtained by the pattern comparison. In order to eliminate the possibility of failing to characterize the face value of the scanned banknote and at the same time reduce the possibility that the counterfeit note is identified as belonging to a valid face value, as described in detail below, Use the two-level threshold of correlation as the basis for creating a "yes" call.

By using the detection correlation method described above, CPU 30 counts the number of bills belonging to a particular currency denomination as part of a given set of bills scanned for a given scan batch, and scans during a scan batch. Is programmed to determine the total amount of currency represented by the indicated bill. Further, the CPU 30 is connected to an output unit 36, which provides an indication of the number of bills counted, a breakdown of the bills for currency denominations, and a total of the face value of the currency represented by the counted bills. To give. The output unit 36 may print out the displayed information in a desired format.

Referring now to FIG. 2, a preferred circuit configuration for processing and correlating reflection data in accordance with the system of the present invention is shown in block diagram form. As shown, CPU 30 accepts and processes various input signals, including signals from optical encoder 32, photoelectric detector 26, and memory unit 38. The memory unit 38 may be a static random access storage (RAM) or an erasable programmable read-only storage (E
PROM). A correlation program is stored in the memory unit 38, and a pattern is generated based on the program, and is compared with a master program in which the test pattern is stored in order to confirm the denomination of the test currency. The crystal 40 serves as a time reference for the CPU 30, to which an external reference voltage V _REF has been applied, and as described below, peak detection of the detected reflection data is performed based on this voltage.

The CPU 30 receives a timer reset signal from the reset unit 44, and the reset unit 44 receives an output voltage from the photoelectric detector 26 as shown in FIG. A value, typically 5.0 volts, is compared by threshold detector 44A and provides a reset signal that goes "high" when a reflection value corresponding to the presence of paper is detected. More specifically, reflection sampling is based on the premise that the illuminated light strip (24 in FIG. 1) will not be reflected back to the photodetector if no banknote is placed below the scan head. Under these conditions, the output of the photodetector represents a "dark" or "zero" level reading. The output of the photodetector has a value of "white", typically about 5.0 volts, when the edge of the note is first placed under the scanning head and under the light strip 24. It changes to the set reading. When this occurs, reset unit 44 provides a "high" signal to CPU 30 to record the start of the scanning procedure.

According to a feature of the present invention, the thickness of the illuminating light strip generated by the light source in the scanning head is set to be relatively small in the first stage of the scan in which a thin border line is detected. . The use of narrow slits increases the sensitivity of the detection of reflected light and allows for small variations in the "ash" level reflected from the bill surface to be detected. This is important to ensure that the thin border lines of the pattern, ie the starting point of the printed pattern on the banknote, are accurately detected. Upon detection of the fringe line, then reflection sampling is performed based on a relatively wide light strip in order to scan completely over the narrow dimension of the banknote and to obtain the desired number of samples quickly. When a wide slit is used for actual sampling, the output characteristics of the photoelectric detector are smoothed and a relatively large analog voltage is realized. This is important for accurate display and processing of the detected reflection values.

Returning to FIG. 2, the CPU 30
6 is processed through a peak detector 46. The peak detector 46 essentially functions to take the output voltage of the photodetector and hold the highest or peak voltage value encountered after activation of the detector. Further, the peak detector is adapted to determine a reference voltage, based on which a border line of a pattern on a bill is detected.
Detector 46 includes an ADC 48 for digitizing the output of the photoelectric detector and a digital-to-analog converter for reconverting the signal to analog based on a preselected reference voltage V _REF from power supply 42. (DAC) 50. The output of the DAC 50 is provided through a transcoder 52 to a voltage divider 54, which reduces the input voltage to a reference voltage V _S that represents a predetermined percentage of the peak value. Voltage V _S, the change of the peak detection to a relatively low "ash" reflection value when encountered from the reflection values have "high" by the scanning the edges unprinted paper money and the thin borderline Based on the percentage decrease in the peak detector output voltage as represented by the detector. Preferably, the reference voltage V
_S is set to be about 70% to 80% of the peak voltage.

The reference voltage V _S is supplied to a curve detector 56, which is provided with an incoming instantaneous output of the photoelectric detector 26. Curve detector 56 compares the two voltages at its input and generates signal L _DET . This signal usually stays "low" and goes "high" as the edges of the bill are scanned. Signal L _DET, when reaching the predetermined percentage of the peak voltage of the photoelectric detector to the point that comes input and output of the photoelectric detector is represented by the voltage V _S, towards the "low". Thus, when the signal L _DET goes "low", this is an indication that a border line in the banknote pattern has been detected. At this point, the CPU 30
The actual reflection sampling is started under the control of FIG. 2 (see FIG. 2) and the desired predetermined number of thankful samples are taken as the bill moves across the illuminated light strip and is scanned along its narrow central section. Is obtained.

When a master feature pattern is generated,
The reflected sample obtained by scanning the "new" note enters the corresponding designated section in system memory 60. The system memory is preferably an EEPROM. Sample input is provided through buffer address latch 58 if necessary. Preferably, the master pattern is generated by scanning the "new" bill a plurality of times, typically three times, to obtain the average of the corresponding data sample before storing the average as representing the master pattern. . During banknote identification, the reflection values obtained by scanning the test banknote are passed through each of the corresponding feature patterns stored in the EEPROM 60 under the control of a correlation program stored in the memory unit 38 and again through the address latch 58. Compare sequentially.

Referring now to FIGS. 4-10, there are shown flow charts illustrating the sequence of operations involved in implementing the optical detection correlation technique of the present invention described above. In particular, FIG. 4 illustrates the sequence required to detect the presence of a note under the scan head and the presence of a border line on the note. This section of the system program, indicated as "trigger", is started at step 70. In step 71, a determination is made as to whether to perform a bill start interrupt. This means that the system is ready for a search for the presence of a banknote and is set, ie it is happening. If the answer in step 71 is yes, control is passed to step 72, which confirms the presence of a note under the scan head based on the reset procedure described above with respect to the reset unit 44 of FIG. .

If the answer in step 72 is yes, that is, if a banknote is present, the process moves to step 73, in which the border value is determined based on the peak value having decreased to its predetermined percentage. A test is performed to see if a line has been detected. As described above, the decrease in the peak value is indicated by the signal L _DET going “low”. If the answer in step 73 is no, the program loops until a border line is detected. If the answer in step 72 is no, that is, if the bill is not present, the bill start interrupt is reset in step 74 and the program returns from the interrupt in step 75.

If it is found in step 73 that a borderline has been detected, a step 76 is invoked in which the A / D completion interrupt is enabled, whereby the analog-to-digital conversion is followed by the desired time. Indicates that it can be done at intervals. Then, at step 77, the time at which the first reflection sample should be obtained is determined in relation to the output of the optical encoder. In step 78, the capture and digitization of the detected reflected sample is undertaken by recalling a routine designated as "STARTA2D", described in detail below. At the completion of the digitization process, a note termination interrupt is enabled at step 79, which resets the system to detect the presence of subsequent notes to be scanned. Then, at step 80, the program returns from the interrupt. If a bill start interrupt was not made in step 71, a determination is made in step 81 to know if a bill end interrupt has occurred. If the answer in step 81 is no, the program returns from the interrupt in step 85.
If a yes answer is obtained in step 81, step 83 is called, in which a bill start interrupt is activated, and the resetting unit monitoring the presence of the bill determines in step 84 the presence of the bill. Reconfigured to be ready. Then the program proceeds to step 85
To return from interrupt.

Referring now to FIGS. 5 and 6, there are shown a routine for initiating the STARTA2D routine and its digitizing routine, respectively.
In FIG. 5, the START2D routine is initiated at step 90 to initialize a sample pointer that provides an indication of a sample obtained and digitized at a predetermined time. Then, at step 91, the particular channel on which the analog-to-digital conversion is to be performed is enabled. An interrupt permitting digitization of the first sample is enabled in step 92 and the main program is called again in step 93.

FIG. 6 is a flowchart showing a sequential procedure necessary for the analog-to-digital conversion routine, which is shown as "A2D". This routine is executed in step 10
Start with 0. The sample pointer is then moved to step 10 to maintain an indication of the number of remaining samples to be obtained.
Decreases by 1. At step 102, digital data corresponding to the output of the photodetector for the current sample is read. This data is converted to its final form at step 103 and stored in a predetermined memory segment with XIN
Is stored as

Next, at step 105, it is checked whether or not a desired predetermined number of samples "N" has been obtained. If the answer is no, step 106 is called, in which case an interrupt allowing the digitization of the subsequent sample is enabled and the program returns from step 1 to complete the rest of the digital program.
Return at 07. However, if the answer in step 105 is yes, that is, if the desired number of samples has already been obtained, a flag indicating this is set in step 108 and the program returns from the interrupt in step 109.

Referring now to FIG. 7, there is shown the sequential means necessary to implement a routine designated as "EXEC" that performs the mathematical steps required for the correlation process. The routine starts at step 110. In step 111, all interrupts are disabled, and the CPU is initialized at this time. In step 112, constants associated with the sample process are set, and in step 113, a communication protocol (protoc) for exchanging the processed data, if any.
ols) and related results, bad rate
s), interrupt mask, etc. are defined.

In step 114, the resetting unit, which indicates the presence of the bill, is reset to detect the presence of the first bill to be scanned. At step 115, the note start interrupt is enabled, causing the system to wait for the first incoming note. Then, step 116 enables all other associated interrupts. This is because at this point the initialization process is complete and the system is ready to begin scanning bills. A check is made at step 117 as to whether the desired number of samples has actually been obtained. If the answer at step 117 is no, the program loops until a yes answer is obtained. When a yes answer is obtained, step 118 is called, in which a flag is set, indicating the start of the correlation procedure.

In accordance with the present invention, a simple correlation procedure is used to process the digitized reflection values into a form that is conveniently and accurately compared to the corresponding values previously stored in the same format. You. More specifically, as a first step, an average value X (compare n samples) of a set of digitized reflection samples obtained for a banknote scan is obtained as follows.

[0048]

(Equation 1)

Next, the normalization factor “σ” is determined to be equal to the sum of the squares of the differences between each sample and the average, as normalized by the total number of samples. More specifically, the normalization factor is calculated as follows.

[0050]

(Equation 2)

The final step is to obtain the difference between the sample and the average calculated above and divide this by the square root of the normalized factor sigma "σ", as defined in the following equation: Normalize each reflection sample by

[0052]

(Equation 3)

Using the correlation equation described above, following the normalization process, the sum of the product of the test pattern and the corresponding sample in any master pattern that exists between the test pattern and the master pattern is calculated as When the patterns are the same, a correlation relationship equal to 1 is obtained. Otherwise, a value less than 1 is obtained. Thus, the correlation number, a factor obtained by comparing the normalized sample in the test pattern with the stored master pattern, clearly indicates the degree of similarity or correlation between these two patterns. .

According to a preferred embodiment of the present invention, the predetermined number of digitized and normalized reflection samples for banknote scanning is selected to be 64. It should be noted that the use of higher order samples (128, 256, etc.) in binary does not result in a correspondingly increased identification efficiency for the large processing time required to perform the above-described correlation procedure. I know from experience. In addition, the use of binary digits smaller than 64, such as 32, significantly reduces identification efficiency.

To facilitate correlation, the correlation factor can be conveniently expressed in binary. For example, in the preferred embodiment, a factor of 1 when there is 100% correlation is represented by 2 10 in binary, which is equal to 1024 in decimal. To determine the particular stored pattern to which the test pattern most closely corresponds by identifying the comparison that yields a correlation number closest to 1024, the normalized sample in the test pattern is determined using the procedure described above. Compare with each of the 28 master feature patterns stored in the system memory.

According to a feature of the present invention, a two-level threshold of correlation must be satisfied before making a particular call.
More specifically, the correlation procedure is adapted to identify the two highest correlation numbers obtained by comparing the test pattern to one of the stored patterns.
At this point, it is necessary to satisfy the minimum threshold value of the correlation with these two correlation numbers. It has been empirically found that a correlation number of about 800 serves as a good threshold, above which the call of yes is made with high accuracy and below this correlation number any of the stored patterns. The display of the test pattern corresponding to the pattern of the above is uncertain. As a second threshold level, the minimum separation between the two highest correlation numbers before the call is defined. by this,
A positive yes is only made when the test pattern does not correspond to one or more stored master patterns within a predetermined correlation range. Preferably, the minimum separation between the correlation numbers is set to be between 100 and 150.

Referring now to FIG. 7, the correlation procedure begins at step 119, where "PROCE"
The routine labeled "SS" is called. FIG. 8 shows a procedure necessary for implementing this routine. FIG.
9 shows a routine started in step 130. Step 1
At 31, the average value X is calculated based on the equation (1).
In step 132, the sum of the squares is calculated according to equation (2). In step 133, for further processing,
Convert the digitized value of the reflection samples, expressed in integer format, to floating point format. At step 134, a check is made as to whether all samples have been processed, and if the answer is yes, the routine proceeds to step 13
The process ends with 5 and the main program is called again. If the answer in step 134 is no, the routine returns to step 132 where the above calculations are repeated.

At the end of the PROCESS routine, the program returns to the routine EXEC at step 120, where the flag indicating that all digitized reflection samples have been processed is reset. Then, Step 1
At 21 the routine labeled "SIGCAL" is called. FIG. 9 shows a procedure required to execute this routine.
Shown in FIG. 9 shows a routine that starts at step 140. In step 141, the square root of the sum of squares is calculated according to equation (2), as calculated by the routine PROCESS. In step 142, the routine PROC
The floating point value calculated by the ESS is normalized according to the equation (3) using the value calculated in step 141.
Step 143 checks whether all digital samples have been processed. If the answer in step 143 is no, the program returns to step 142 and continues the conversion until all samples have been processed. At this point, the answer in step 143 is yes, and the routine returns to the main program in step 144.

Returning to the flowchart of FIG. 7, the next step to be performed is step 122, in which the routine labeled "COREL" is called. Fig. 1 shows the procedure required to implement this routine.
0 is shown. FIG. 10 shows that this routine starts at 150. In step 151, the correlation result is initialized to 0, and in step 152, the test pattern is compared with the first one of the stored master patterns. In step 153, the first call corresponding to the highest correlation number obtained up to this point is determined. In step 154, the second call corresponding to the second highest correlation number obtained up to this point is determined. Step 1
At 55, a check is made as to whether the test pattern has been compared to all master patterns. If the answer is no, the routine returns to step 152 where the comparison procedure is repeated. When all master programs have been compared to the test pattern, step 155 answers yes and the routine returns to the main program at step 156.

Returning to FIG. 7, a flag indicating that the correlation procedure has been completed is reset in step 123, step 124 is called, and "SEROUU" is executed in this step.
The routine labeled "T" is started. Step 11
Note that 8 and 123 relate to the setting and resetting of flag TP2, which has the primary function of measuring the processing time required for the entire correlation procedure. These steps may be omitted if the processing time is not monitored.
FIG. 1 shows the procedure required to execute the routine SEROUT.
It is shown in FIG. FIG. 11 shows that this routine starts at step 160. In step 161, the denomination corresponding to the first call is converted into ASCII format and displayed. In step 162, the correlation number corresponding to the first call is converted into an ASCII format and displayed.

In step 163, the denomination corresponding to the second call is converted into ASCII format and displayed. In step 164, the correlation number corresponding to the second call is converted into ASCII format and displayed. Then, the routine returns to the main program. At this point, in the main program, the correlation procedure is completed and any relevant counts identifying the denomination are made on the relevant results and displayed along with the corresponding calls and correlation numbers. After completing this correlation-display procedure, the system is ready to begin the scanning process for the next incoming bill.

In implementing the optical detection and correlation technique of the present invention, (i) in performing the sampling and correlation processes,
(Ii) It should be noted that separate microprocessor units may be provided to control the overall functionality of the entire system. In such an embodiment, the overall processor unit is preferably used to display the identified denomination and any associated counting results.
In this method, the routine SEROUT (see FIG. 11)
Only requires the transmission of the denomination of the bill and the call of information from the sampling-correlation processor unit to the entire processor unit for subsequent display.

Referring now to FIGS. 12-14, there are shown in these figures a test pattern produced when a one dollar bill is scanned forward along its surface, and a two dollar bill is reversed on its surface. And the test pattern that results when a $ 100 bill is scanned forward around its surface, respectively. FIG.
In FIG. 14 to FIG. 14, unlike the preferred method of using only 64 samples for the purpose of clarifying the test pattern,
Note that FIGS. 12-14 were created by using 128 reflection samples per banknote scan. For these three test patterns,
The recorded differences that exist between the corresponding samples are indicative of a high degree of accuracy, with which the denomination is called using the optical detection correlation procedure described above.

The optical detection correlation technique described above allows for the identification of preprogrammed physics with high accuracy, and the optical detection correlation technique described above digitizes sampled reflection values and compares these values to a master feature pattern. To do so is based on a relatively small processing time. This method scans banknotes, normalizes the scanned data, and the active banknote scan provides a direct correspondence between the compared sample points of the most discriminatively-printed banknote sections. Used to generate a master pattern to have. A relatively small number of reflection samples is required to be able to properly distinguish between several denominations.

The main advantage of this method is that the bill does not have to be scanned along its wide dimension. Prior systems have typically been forced to scan wide dimensions to obtain the greater number of samples needed to accurately identify the denomination. In addition, reducing the number of samples reduces processing time to the extent that additional comparisons can be made during the time available between successive banknote scans.
More specifically, as described above, the test pattern can be compared to at least four stored master feature patterns, so that the system can use the "front" or "back" It is designed to identify banknotes that are scanned in the "forward" or "reverse" direction.

Another advantage resulting from the reduction in processing time achieved with the detection correlation method of the present invention is "counterfeiting", ie, stopping the transfer of bills identified as not corresponding to any of the stored master feature patterns. Or the diversion of such banknotes to another stacker bin is correspondingly shortened in response time. Therefore, this system
If the scanned pattern does not correspond to any of the master patterns, it can be conveniently programmed to set a flag. Identification of such a condition can be used to stop the bill transfer drive motor for the mechanism. Since the optical encoder is associated with the rotational movement of the drive motor, synchronization can be maintained between the state before the stop and the state after the stop. In the two-processor embodiment described above, information about the identification of the "counterfeit" bill is included in the information transmitted to the overall processor unit, which in turn controls the drive motor appropriately.

The accuracy of the correlation procedure and the denomination identified by this procedure is directly related to the degree of correspondence between the reflected sample on the test pattern and the corresponding sample of the stored master pattern. Thus, the shrinkage of "spent" notes reduces their narrow dimensions correspondingly, reducing the degree of correlation between such used notes at a given denomination and the corresponding master pattern. Sometimes. For heavily worn banknotes, such a reduction occurs in both the narrow and wide dimensions of the banknote. The detection correlation technique of the present invention remains relatively independent of changes in the broad dimension of the banknote, and the decrease along the narrow dimension is obtained as the "shrinked" banknote is transported across the scan head. The correlation factor may be affected by realizing the relative shift of the reflected sample that is obtained.

In order to absorb such an effect of the contraction of the narrow dimension, that is, to reduce the effect to zero, a test pattern which does not correspond to any of the master patterns is divided into predetermined sections, and a continuous Progressive shift of the sample in the selected section
The correlation technique described above may be modified by using a progressive movement method that t) compares again with the stored pattern. It has been empirically determined that such a progressive movement is an effective countermeasure against sample displacement due to shrinkage of a banknote along a narrow dimension.

The effect of progressive movement is best illustrated by the correlation patterns shown in FIGS. For clarity purposes, the example pattern is for each bill scan,
Made using 128 samples compared to the preferred use of 64 samples. FIG. 15 shows the correlation between the test pattern (indicated by a thick line) and the corresponding master pattern (indicated by a thin line). It is clear from FIG. 15 that the degree of correlation between the two patterns is relatively low, exhibiting a correlation factor of 606.

The method of increasing the correlation between these patterns by using a progressive movement is best done by considering the correlation at reference points denoted as A to E along the axis making up the sample number. Is illustrated.
FIG. 16 shows the effect of the “one-time” progressive movement on the correlation. This figure shows the "one time" movement of the test pattern of FIG. This is done by dividing the test pattern into two equal segments, each having 64 samples. The first segment is kept without any movement, while the second segment has been moved by a factor of one data sample. Under these circumstances, the correlation factor is the reference point located in the moved segment,
In particular, at point E, it is improved.

FIG. 17 shows the effect obtained by performing the gradual movement "twice". The sections of the test pattern are thereby moved in three stages. This is done by dividing the entire pattern into three approximately equally sized sections. Partition 1 has not been moved, partition 2 has been moved by one data sample (as shown in FIG. 16), and partition 3 has been moved by a factor of two data samples.
It can be seen that the “twice” movement further increases the correlation factor at point E.

Based on a similar criterion, FIG. 18 shows the effect that the "three" gradual movements have on the correlation, in which the entire pattern is first divided into four substantially equally sized sections. Then, keep section 1 unchanged, move section 2 by one data sample, move section 3 by 2 data samples, and move section 4 by 3 data samples. It can be seen that the correlation factor at point E is further increased in such a state.

FIG. 19 shows the effect that the "four times" movement has on the correlation, in which the pattern is divided into five approximately equally sized sections. The first four sections are moved according to the method of performing the "three" moves of FIG. 18, while the fifth section is moved by a factor of four data samples. From FIG. 19, it is clear that the correlation at point E is increased until it substantially matches the overlap of the compared data samples.

The advantage of using the progressive shifting method is that, unlike quite simply moving by a set amount of data samples, the improvement in correlation obtained in the first section of the pattern as a result of the shifting is the test pattern. Are not offset by subsequent movements. It is clear from the above figure that the degree of correlation for sample points falling within the progressively shifted section increases correspondingly.

More importantly, the progressive movement provides a large increase in the overall correlation factor obtained by comparing the patterns. For example, the correlation factor which was originally 606 (see FIG. 15) is increased to 681 by the “single” movement shown in FIG. The “two times” movement shown in FIG. 17 increases the correlation number to 793, the “three times” movement shown in FIG. 18 increases the correlation number to 906, and finally the “four times” movement shown in FIG. Increases the total correlation number to 960. Using the method described above, a narrowed dimension is considerably shrunk, and a used bill that cannot be accurately identified as belonging to a correct denomination when correlation is performed without performing any movement, using a progressive movement method, Preferably, identification can be performed with high accuracy by employing "three times" or "four times" movement.

Referring now to FIG. 20, there is shown an apparatus 210 for currency identification and counting embodying the principles of the present invention. This device is located on the left side wall 21
4, right wall 216, rear wall 218, reference numeral 220 throughout
Has a housing 212 that includes a top surface to which is attached. The device comprises a front section 222 having a generally vertical forward section 224 and a forward slope section 225, wherein the forward slope section 2
25 is a control panel 226A to which various control switches for operating the device and associated display means are mounted.
And 226B.

The input bin 227 on the upper surface 220 by the downwardly inclined support surface 229 to accept a stack of banknotes 228 that must be identified according to face value.
Is formed. A pair of vertically arranged side walls 230 and 232 are provided on the support surface 229, and these side walls are connected to each other by a vertically arranged front wall 234. The walls 230, 232, 234 cooperate with the inclined surfaces 229 to form an enclosure in which the stack of banknotes 228 is positioned.

The bill moves from the input bin along a transport path with three sections. The moving path is an input path in which the bill moves along the first direction at a substantially flat position, a curved guide path that receives the bill from the input path and guides the bill to change the moving direction to the second different direction, The banknote has an output path that travels in a flat position along a second different direction across a banknote identification means, which will be described in more detail below, which is located downstream of the curved guideway. In accordance with the improved optical detection and correlation techniques of the present invention, the transport path is adapted to receive bills and transport them along input, curved guide and output paths, so that the narrow dimension "W" of the bills is transferred to the transport path. And it is configured to be stacked while always being kept parallel to the moving direction.

The forward inclined section 22 of the document handling device 210
5 has a centrally located platform surface 235 between the side walls 214, 216, which platform surface 235 has a stacker plate 242 on which the processed banknotes are stacked for subsequent processing of the banknotes processed by the banknote recognition means. , And accept it. More specifically, platform 235 has an associated angular surface 236 and includes openings 237, 237A from which
Flexible blades 238A, 240A of corresponding pairs of stacker wheels 238, 240 extend outwardly, respectively. These stacker wheels are supported for rotational movement about a stacker shaft 241 that is disposed about the angled surface 236 and suspended across the side walls 214 and 216. The flexible blades 238A, 240A of the stacker wheel cooperate with the stacker platform 235 and the openings 237, 237A to remove the sent bill. The blades then operate to deliver such bills to the stacker plate 242.
The stacker plate 242 is connected to the angled surface 236, and the stacker plate also has stacker wheel openings, through which the wheels protrude. In operation, bills delivered to the stapler plat home 235 are picked up by a flexible blade and fall between a pair of adjacent blades, which combine to form a curved envelope, which surrounds the envelope. It serves as a means for decelerating bills that have entered therein, supporting them as the stacker wheel rotates, and transporting them from the stacker platform 235 onto the stacker plate 242. The mechanical configuration of the stacker wheel and the flexible blades provided on the stacker wheel, and the manner in which they cooperate with the stacker platform and the stacker plate, are conventional and, therefore, are described in detail herein. do not do.

The bill handling and counting device 210 is provided with means for taking out bills, that is, "peeling" bills one by one from bills stacked in the input bin 227. To provide this peeling action, a supply roller 246 is rotatably mounted about a drive shaft 247 and the drive shaft 247 is
Supported between 16 The supply roller 246 projects through a slot provided in the downwardly inclined surface 229 of the input bin 227, which forms an input path.
The supply roller 246 is in the form of an eccentric roller having a relatively high friction support surface 246A on at least a portion of its periphery. The surface 246A is adapted to engage with the lowest bill of the stack of bills 228 when the roller 246 rotates, whereby the lowest bill along the supply direction indicated by the arrow 247B (see FIG. 22). Movement is started. The eccentric surface of the feed roller 246 essentially "rocks" the stack of bills once per revolution to move and loosen the lowest bill in the stack. This facilitates the advance of the lowest bill along the supply direction.

The function of the supply roller 246 is supplemented by the provision of a capstan or drum 248 supported for rotational movement about a capstan drive shaft 249. The capstan drive shaft 249 is connected to the side wall 2
14 and 216 are supported. Preferably, capstan 248 has a centrally located friction roller 248A having a smooth surface and formed of a friction-providing material such as rubber or hard plastic. The friction roller is sandwiched between a pair of capstan rollers 248B and 248C, and at least a part of the outer circumference of these capstan rollers is provided with a surface 248D that provides high friction.

The friction surface 248D is similar to the friction surface 246A provided on the supply roller, so that the capstan roller can frictionally move the lowest bill along the supply direction. Preferably, capstan 24
8 and the supply roller 246 are synchronized such that the friction surfaces provided around the capstan and the supply roller rotate together, thereby causing the stack 228 of banknotes to rotate.
Induces a complementary frictional contact with the lowest bill of money.

The capstan 248 and the supply roller 246
A take-off roller for exerting a constant downward force on the leading edge of the banknotes located in the input bin 227 to ensure effective contact with the banknotes in the process of being agitated, propelled and advanced by 252A and 252B are provided. These take-off rollers are supported on corresponding take-out arms 254A, 254B, which are supported to move in an arc about a support shaft 256 supported between the side walls of the device. . The take-out roller is designed to rotate freely about the take-out arm, and if there is no banknote in contact with the capstan 248, the take-up roller rests on the friction roller 248, and therefore, moves in a direction opposite to the friction roller. Rotation is induced. However, there are banknotes and capstan 24
When it comes into contact with the bill 8, the take-out roller rests on and comes into contact with the leading edge of the bill, which impedes the rotational movement of the roller and exerts a downward force on the bill. As a result, the advancing action created by the contact between the friction-providing surfaces 248D on the capstan rollers 248B, 248C is enhanced, thereby removing the notes one at a time from the note stack 28. Is made easier.

Between the take-out arms 254A and 254B,
The support shaft 256 further supports the separation arm 260,
The separation arm supports a stationary stripper shoe 258 at its end remote from the shaft, and the stripper shoe is provided with a friction surface that provides frictional resistance on the bill on which the pick-up roller rests. The separation arm is mounted for movement in an arc about the support shaft 256, and the arm is spring-loaded to abut against the capstan downwardly with a selected amount of force.

In operation, because of their freely rotating nature, the take-off rollers rotate with the rotational movement of the friction roller 248A until it encounters the leading edge of one or more notes. Upon encountering the bill, the rotational movement of the pick-up roller is stopped, forcing the leading edge of the bill into positive contact with the friction-providing surface on the periphery of the capstan roller. The effect of this is to force the lowest bill away from the remaining bills along the direction of capstan rotation. At the same time, the separation shoe 258 also abuts on any of the bills pushed forward by the capstan roller.

[0086] The tension acting on the dispensing arm 254A is selected so that the downward force exerted on such a propelled bill can move only one bill forward. If two or more bills are pushed out of the contact created between the pick-up roller and the capstan roller, the downward force exerted by the spring-loaded shoe will cause these bills to It must be sufficient to prevent further forward movement. The spring loaded tension of the pick arm can be conveniently adjusted to control the downward supporting force exerted by the shoe to supplement the bill peeling action created by the pick roller and capstan roller. Thus, the likelihood that two or more bills will be pushed forward simultaneously by the rotational movement of the capstan is greatly reduced.

The bill transfer path is provided forward along the input path formed by the front section of the inclined surface 229, and in front of the capstan 248 for receiving the bill propelled into frictional contact with the rotating capstan. Curved guideway 2
70. Guideway 270 has a curved section 272,
This section substantially corresponds to the curved perimeter of capstan 248 so as to supplement the kinetic force that capstan rollers 248B, 248C exert on the torn bill.

The capstan 2 is provided in the curved guideway 270.
A pair of idler rollers 262A, 262B is provided downstream of the take-out roller to guide the bill propelled by 48. More specifically, these idler rollers are mounted on corresponding idler arms 264A, 264B, which are mounted for movement in an arc about idler shaft 266, which idler shafts It is supported over the side wall. The idler arm is spring-loaded on the idler shaft so that a selected downward force can be exerted on the peeled banknotes via idler rollers, thereby causing the banknotes to pass through the guideway 270.
To ensure continuous contact between the bill and the capstan 248 until it is guided into the curved section 272 of the bill.

The bill transfer path has an output path for bills downstream of the curved section 272. This output path is a flat section 274
And the idler rollers 262A, 262
The bill guided along the guide path 270 curved by B is moved along this flat section in a direction opposite to the direction in which the bill exits the input bin. Pickup roller 2
52A, 252B and capstan rollers 248B, 2
The rotation direction of the capstan provided by 48C and the movement of the banknotes along the guidance provided by section 272 of curved guideway 270 can be achieved by tilting input bin 227, as best shown in FIG. The direction of movement of the banknote is changed from an initial movement along surface 229 (see arrow 247B in FIG. 22) to a direction along flat section 274 of the output path.

The bills peeled off from the stack of bills in the input bin are first taken out by the take-out rollers 25.
2A, 252B and capstan rollers 248B, 248
It moves along the input path while receiving positive contact with C. Then, the banknotes are idler rollers 262A,
Guide path 27 curved in a state of being in positive contact with 262B
0 on the flat section 274 of the output path.

In the output path, banknotes are positively guided along the flat section 274 by the transport roller device. The transfer roller device includes a plurality of positively driven axially spaced transfer rollers 282A, 284A, 28.
6A, these rollers being located on a transfer shaft 287 supported between the side walls of the device. The flat section is provided with openings through which at least two of the transport rollers, in particular rollers 282
A, 284A project and are in reverse rotational contact with the corresponding freely rotating passive rollers 292A, 294A. The passive rollers are mounted on a support shaft 295 supported between the side walls of the device below the flat section 274 of the output path. The passive transfer rollers 292A, 294A are spring-loaded into reverse rotational contact with the active transfer rollers 282A, 284A, 286A, and the points of contact are flattened by the active contact between the opposing and active rollers and the passive rollers. In such a state, the banknotes can be moved along the output path so as to be in the same plane as the output path. Active transfer rollers 282B, 284B, 286B and spring-loaded passive transfer rollers 292B facing these rollers;
A similar set of 294B is provided at a distance slightly less than the length of the narrow dimension of the bill to be identified downstream of the first set of transport rollers. Further, the distance between the idler rollers 262A, 262B and the first set of transport rollers is such that the bills guided along the curved guide path 259 are different from the bills between the idler rollers 262A, 262B and the capstan 248. Shortly before moving away from the positive contact of the first roller, it is selected to be drawn into contact between the first set of active and passive rollers. Active transfer rollers are driven at a much higher speed than capstan rollers. The first set of transfer rollers causes the banknotes fed between the rollers along the first section of the output path to rotate between the active rollers and the passive rollers, as the passive rollers rotate freely and the active rollers are actively driven. Is drawn into the nip formed between them. The high speed of the active transfer rollers adds sudden acceleration to the banknote. This acceleration serves to separate or tear the bill from any other bill guided in the curved guideway with the bill under the action of the transport rollers.

Downstream of the first set of transfer rollers, the notes move along flat sections into the nip formed between the second set of active and passive transfer rollers. The rollers of the second set of active and passive transfer rollers are rotated at the same speed as the first set of transfer rollers. Preferably, a set of opposed active transport rollers 282A-282
B, 284A-284B, and 286A-286B are associated with each other at the base 290 so that the passive rotation of the transfer shaft 287 is applied to the rollers supported on the second transfer shaft 288. The second set of transfer rollers is arranged such that the active contact exerted by the rollers on the bill traveling along the output path occurs before the bill is released from passive contact between the first set of transfer rollers. ing. Thus, the second set of transport rollers passively guides the bill onto the stacker platform 235 where the stacker wheels 238, 240 pick up the bill and place it on the stacker plate 242.

Referring now specifically to FIGS. 23 and 24, there are shown a side view and a plan view of the document processing apparatus of FIGS. 20, 21, and 22, respectively. In each of these side and plan views, bills are transported along three sections of the transport path: a section along the input path, a section along the curved guideway, and a section along the output path. A mechanical arrangement for driving the various means is shown. As shown in these figures, the motor 300 uses a belt / pulley device to rotate the capstan shaft 24.
Used to add to 9. The belt / pulley device includes a pulley 310 provided on a capstan shaft 249.
And a pulley 310 is associated via a belt 306 with a pulley 304 provided on the drive shaft of the motor. The diameter of drive pulley 310 is selected to be suitably larger than motor pulley 304 to obtain the desired deceleration from the typical high speed at which motor 300 operates.

Drive shaft 247 for drive roller 246
Is rotated by a pulley 308 provided on the shaft, and the pulley 308 is associated with a corresponding pulley 310 provided on the capstan shaft 249 via a belt 312. Pulleys 308 and 310
Are the same diameter pulleys, so that the drive roller shaft 247, and thus the drive roller 246, is mounted on a capstan shaft 249 with a capstan 248.
Rotate in accordance with.

In order to apply a rotating motion to the transfer roller, the first
Roller shaft 287 corresponding to the set of
A pulley 314, which is associated with a corresponding pulley 316 of the capstan shaft 249 via a belt 318. Transfer roller pulley 31
The diameter of 4 is selected to be suitably smaller than the diameter of the corresponding capstan pulley 316 so as to achieve a gradual increase in speed from the capstan roller to the transfer roller. A second set of transfer rollers mounted on a transfer roller shaft 288 is connected to a first pulley 320 associated with a transfer pulley 314 via a belt 322.
Are driven at the same speed as the rollers in the set of transfer rollers.

As shown in FIGS. 23 and 24, the optical encoder 299 is used to control the lateral direction of the bill supported by the transport rollers, as discussed in detail above in connection with the optical detection correlation technique of the present invention. To accurately track the movement with respect to the rotational movement of the transfer shaft, it is mounted on one of the transfer roller shafts, preferably a passively driven transfer shaft 288.

To drive the stacker wheels 238, 240, an intermediate pulley 322 is mounted on suitable support means (not shown), the pulley being a belt and a corresponding pulley 324 provided on a capstan shaft 249. Via 326. Due to the time required to transfer the bills peeled from the stack of bills in the input bin onto the stacker platform through a transfer path with three sections, they can be rotated to deliver the processed bills to the stacker plate. The speed of the stacker wheel is necessarily lower than the speed of the capstan shaft. Accordingly, the diameter of the intermediate pulley 322 is selected to be larger than the diameter of the corresponding capstan pulley 324 so as to achieve deceleration. Intermediate pulley 322 is associated with pulley 3
28, which have a stacker wheel 238,
The belt 332 is related to a stacker pulley 330 provided on a drive shaft 241 for 240. In the preferred embodiment shown in FIGS. 20-24, the stacker wheels 238, 240 rotate in the same direction as the capstan rollers. This is because the belt 332 between the pulleys 328 and 330
With a fixing pin 33 arranged between these two pulleys.
This is done by constructing a figure "8" shape centered at three.

The curved section 272 of the guideway 270 is a light emitting diode for performing standard banknote handling operations such as counterfeit banknote detection operations using conventional techniques such as double detection, length detection, and skew detection. An optical sensor device 299 including an (LED) 298 is provided below. However, unlike conventional devices, bill identification according to face value is not performed in this area for the reasons discussed below.

In accordance with a feature of the present invention, the optical scanning of banknotes by the improved optical detection and correlation technique described above comprises an optical path disposed downstream of curved guideway 270 along a flat section 274 of the output path. This is performed by the scanning head 296. More specifically, the optical head 296 is located between the two sets of transport rollers under a flat section of the output path. The advantage of this method is that the optical scanning is performed when the note is kept almost flat as a result of the passive contact between the two sets of transport rollers at both ends of the note along the narrow dimension of the note. That is to be done.

It will be appreciated that the above described drive has been given by way of example. A variant configuration for applying the necessary rotational movement to effect the movement of the banknote along the transport path with three sections may likewise be used effectively. However, it is important that the surface speed of the bill across the two sets of transport rollers must be greater than the speed of the bill across the capstan rollers to achieve optimal bill separation. It is this speed difference that causes a sudden acceleration of the bill when it comes into contact with the first set of transport rollers.

The driving device may have a one-way clutch (not shown), which is provided on a capstan shaft, and a flywheel device is provided on the capstan shaft, the transfer roller shaft, and the stacker wheel shaft. (Not shown) may be provided. The combination of the one-way clutch and the flywheel allows the banknotes remaining in the transfer path after the banknote identification to be automatically pulled out of the transfer path into the stacker plate by the inertia force of the flywheel device, thereby quickly moving the bills. It can be used advantageously for performing a batch processing.

As described above, the implementation of the optical detection correlation technique of the present invention requires only a relatively small number of reflection samples to properly differentiate among several denominations of a currency. Thus, a very accurate identification can be made even when the bill is scanned along its narrow dimension. However, the accuracy of the denomination identification is based on the degree of correlation between the reflected sample on the test pattern and the corresponding sample of the stored master pattern. It is therefore important that the bills are transported across the identification means in a flat state, and more importantly, at a uniform speed.

This is done in the banknote handling apparatus shown in FIGS. 20 to 24 by positioning the optical scanning head 296 on one side of the flat section 274 of the output path between the two sets of transport rollers. In this area, the bill is kept in passive contact with the two sets of rollers, thereby causing the bill to move substantially flat across the scan head. Further, in this area, the second set of passive transfer rollers is driven at the same speed by the active transfer roller and the belt connecting these two sets of rollers, so that the uniform movement speed of the bill is maintained. . The optical scanning head 296 has a flat section 274 downstream of the curved guideway.
To maintain a direct correspondence between the reflected sample obtained by optically scanning the bill to be identified and the corresponding sample of the stored master pattern.

According to a preferred embodiment, the optical scanning head has a plurality of light sources that work in combination to evenly illuminate a light strip of the desired size on a banknote positioned on a transport path below the scanning head. . As shown in FIG. 25, scan head 296 includes light beams 340A and 340 on flat section 274 of the output path where the scan head is positioned.
A pair of LEDs 340 and 342 for pointing B downward, respectively.
Having. The LEDs 340, 342 are arranged at an angle to the vertical axis Y such that their respective rays combine to illuminate the desired light strip 342.

Scan head 296 has a photoelectric detector 346 centrally located just above the strip to detect light reflected from the strip. The photoelectric detector 346 is
Associated with a central processing unit (CPU) (not shown) for processing the detected data according to the above principles of the present invention. Preferably, light beams 3 from LEDs 340, 342 are provided to achieve an illuminated strip of the desired dimensions.
40A and 340B pass through the optical mask 343, respectively.

To capture the reflected sample with high accuracy,
It is important that the photoelectric detectors capture the reflection data evenly across the illuminated strip. In other words, if the photodetector 346 is positioned at the upper center of the light strip with respect to the center point "0" of the light strip, the output of the photodetector, as shown by curve A in FIG. The step function should be approached optimally as a function of the distance from the center point "0" along the X axis. When using a single light source positioned at an angle to the vertical, the variation in the output of the photodetector typically approaches a Gaussian function, as shown by curve B in FIG. .

According to a preferred embodiment, the two LEDs are arranged at angles α and β respectively with respect to the vertical axis. The angles α and β are chosen such that the resulting output of the photodetector is as close as possible to the optimal distribution curve A of FIG. According to a preferred embodiment, the angles α and β
Are each chosen to be 19.9 °. The output distribution of the photoelectric detector realized by this configuration is shown in FIG. 26 by a curve denoted by reference numeral “C”. This curve effectively coalesces the individual Gaussian distributions of the light source and provides a composite distribution that closely approximates the optimal curve A.

FIG. 27 shows a method of producing a plurality of optical strips of various sizes by an optical scanning head by using an optical mask.
Shown in As shown in this figure, the light mask 350 is essentially opaque throughout, formed with two slits 354 and 356 that allow light from a light source to pass to illuminate a light strip of desired dimensions. It has a region 352. More specifically, the slit 354 corresponds to a wide strip used to obtain a reflection sample corresponding to the feature pattern for the test note. According to the illustrated embodiment, the wide slit 354 is approximately 7.62 mm (0.30 mm).
0 inch) and about 1.27 mm (0.050 inch)
Having a width of The second slit 356 is adapted to create a relatively narrow, illuminated slit that is used to detect a thin borderline surrounding the printing of the banknote, as described in detail above. According to an exemplary embodiment,
Narrow slit 356 has a length of about 0.300 inches and a width of about 0.010 inches.

It is clear that high-precision machining is required to form the slit accurately. In fact,
It is difficult to process the narrow slit 356 on the optical mask 350. According to a preferred embodiment, this problem is
This is solved by forming the mask 350 in the form of separate sections 360 and 362. Section 360 is machined such that one edge corresponds to half 356A of desired slit 356. The second clamp 362 is machined such that the corresponding edge corresponds to the other half 356B of the slit 356. When the two sections 360 and 362 are mechanically associated with each other, they effectively form the narrow slit 356. The advantage of this method is that the two halves 356 forming the slit 356 with each other
A, 356B can be formed accurately. This is because the processing performed on the edge of the mask can be handled with much better precision than processing within the mask itself.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating the conceptual basis of an optical detection correlation method and apparatus according to the system of the present invention.

FIG. 2 is a block diagram illustrating a preferred circuit configuration for processing and correlating reflection data in accordance with the optical detection and counting technique of the present invention.

FIG. 3 is a block diagram illustrating a preferred circuit configuration for processing and correlating reflection data in accordance with the optical detection and counting technique of the present invention.

FIG. 4 is a flowchart showing an operation sequence necessary for implementing the optical detection correlation technique.

FIG. 5 is a flowchart showing the sequence of operations necessary for implementing the optical detection correlation technique.

FIG. 6 is a flowchart showing the sequence of operations necessary for implementing the optical detection correlation technique.

FIG. 7 is a flowchart showing the sequence of operations necessary for implementing the optical detection correlation technique.

FIG. 8 is a flowchart showing the sequence of operations necessary for implementing the optical detection correlation technique.

FIG. 9 is a flowchart showing the sequence of operations necessary for implementing the optical detection correlation technique.

FIG. 10 is a flowchart showing the sequence of operations necessary for implementing the optical detection correlation technique.

FIG. 11 is a flowchart showing the sequence of operations necessary for implementing the optical detection correlation technique.

FIG. 12 is a graph of a representative characteristic pattern obtained by optically scanning a narrow dimension of a bill.

FIG. 13 is a graph of a representative characteristic pattern obtained by optically scanning a narrow dimension of a bill.

FIG. 14 is a graph of a representative characteristic pattern obtained by optically scanning a narrow dimension of a bill.

FIG. 15 is a graph illustrating the effect provided on the correlation pattern by using a progressive movement technique according to an embodiment of the present invention.

FIG. 16 is a graph illustrating the effect brought about on a correlation pattern by using a progressive movement technique according to an embodiment of the present invention.

FIG. 17 is a graph illustrating the effect provided on a correlation pattern by using a progressive movement technique according to an embodiment of the present invention.

FIG. 18 is a graph illustrating the effect brought about on a correlation pattern by using a progressive movement technique according to an embodiment of the present invention.

FIG. 19 is a graph illustrating the effect brought about on a correlation pattern by using a progressive movement technique according to an embodiment of the present invention.

FIG. 20 is a perspective view of a bill discriminating and counting device particularly suitable for the optical detection correlation technique of the present invention and embodying this technique.

FIG. 21 is a perspective view showing a mechanism used to separate bills and sequentially send these bills to a transfer path.

FIG. 22 is a side view of the apparatus of FIG. 20, showing the separation mechanism and the transfer path.

FIG. 23 is a side view of the apparatus of FIG. 20, showing details of the drive mechanism.

FIG. 24 is a plan view of the banknote recognition and counting device shown in FIGS. 20 to 23;

FIG. 25 is a side sectional view showing an angular arrangement of light emitting diodes in the scanning head.

FIG. 26 is a diagram showing a distribution of light created around the optical scanning head.

FIG. 27 is a plan view of an optical mask used to create scanning strips of various sizes.

[Procedure amendment]

[Submission date] January 13, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Graves, Bradford Tea 6004, Illinois, United States of America, Arlington Heights, Bloomington Avenue 4173, Number 204 (72) Inventor Strom, Lars Earl, Illinois, United States of America 60004, Arlington Heights, East Olive Street 2403 (72) Inventor, Bauch, Aaron M. 11733, New York, USA, East Setucket, Buckingham Med.

Claims (10)

[Claims] An apparatus for receiving stacked documents and quickly identifying all of the documents, comprising: an entry location for receiving stacked documents to be identified; and identifying the identified documents. A single exit location for receiving, a transport mechanism for transporting the documents one at a time from the entrance location to the exit location along a transport path, and an identification unit for identifying the documents. An identification unit comprising a detector arranged along said transport path between said entrance location and said exit location, adapted to count said documents and to identify said documents; and Means for flagging documents that are satisfied or unsatisfied. 2. The document identification apparatus according to claim 1, wherein said means for outputting said flag is capable of stopping said transfer mechanism. 3. The criterion is that the identification unit performs an identification of the document, and if the identification is not made and thus the document does not satisfy the criterion,
3. The document identification apparatus according to claim 1, wherein the means for outputting the flag stops the transfer mechanism. 4. The document identification device according to claim 1, wherein the document is a currency bill, and the identification unit is configured to count the bill and determine a denomination. 5. The criterion is that the identification unit makes a determination of a denomination of the bill, and the document is not determined by the identification unit for a denomination, and thus the document does not satisfy the criterion. 5. The document identification apparatus according to claim 4, wherein said flag output means stops said transfer mechanism when said flag is set. 6. An output signal indicating the scanned image by the detector of the identification unit scanning at least a predetermined segment of each bill transferred between the entrance location and the exit location by the transport mechanism. A stationary optical scanning head for producing the same, said identification unit comprising signal processing means for receiving said output signal and determining the denomination of each scanned bill. 5. The document identification device according to any one of 5. 7. A method for counting and identifying different types of documents, comprising the steps of: receiving a stack of documents to be identified at an entry location; A method comprising: transferring to an exit location; counting and identifying the documents; and flagging documents that meet or do not meet certain criteria. 8. The method according to claim 7, wherein the document is a currency note. 9. The step of issuing the flag includes stopping the transfer of the banknote, wherein the criterion is to identify the document, and the document is not identified when the document is not identified. 9. A method as claimed in claim 7 or claim 8 wherein a flag is issued for. 10. The step of identifying the document scans a predetermined segment of each bill transported between the entrance location and the exit location using a stationary optical scanning head and presents the scanned image. The method according to any of claims 7 to 9, comprising producing an output signal.