JPS6027438B2 - Banknote identification device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a banknote discriminating device for discriminating the type, authenticity, etc. of banknotes in an automatic teller machine such as an automatic teller machine.

In recent years, automatic teller machines for automating bank transactions have become widespread, and in response, automatic teller machines have also been developed.

Currently, there is a method generally known in which banknotes are inserted one by one in the longitudinal direction, which has the advantage that the direction can be easily controlled when banknotes are taken in. There is a demand for an improved automatic teller machine that can be loaded all at once, as shown in Figure 1. That is, in FIG. 1, a deposit slot 4 consisting of a rotatable cover 2 and a storage box 3 is provided on the front of the housing 1, and a customer deposits banknotes a into the storage box 3.・It is designed to be added all at once while standing. The rear part of the storage box 3 is composed of a pulley 5... and an endless annular belt 6...〇, which sequentially receives the inserted banknotes a one by one. A take-in rotor 8 is provided for taking in the conveyance path 7.

That is, an adsorbent 8a suitable for a vacuum source (not shown) is perforated on the outer circumferential surface of the intake rotor 8, and as the rotor 8 rotates counterclockwise as indicated by the arrow, the banknotes a... . . . are vacuum-adsorbed and taken in one by one, starting from the earliest one. Further, a detection device 9 consisting of a light projecting section 9a and a light receiving element section 9b is disposed in the middle of the conveyance path 7, and performs banknote type determination, counting, and authenticity determination of the banknotes a in the conveyance path 7. ing.

Further, the conveyance path 7 includes a main conveyance path 10a and a branch conveyance path 1.
For example, a rotary sole/
A rotatable division gate 11 is provided which is driven by a division gate.

That is, in response to a signal from the detection device 9, a controller (not shown) sends a signal to the main conveyance path 1 in the case of a correct banknote.
0a, in the case of a fraudulent banknote, it is operated to guide the banknote to the banknote conveyance unit 10b. In this way, the correct banknotes a fed into the main conveyance path 10a are horizontally accumulated in the deposit box 12 provided at the terminal end. Furthermore, reference numeral 13 denotes a vertically movable back-up plate for holding banknotes a, which is supported by one end of a shaft 14 and is controlled to descend sequentially according to the amount of banknotes a accumulated.

On the other hand, fraudulent banknotes a sent to the branch conveyance path 10b
is a return port 15 whose terminal end faces the front of the cliff body 1.
The fraudulent banknote a is then sent to the customer and returned to the customer.

Various devices have been proposed for determining the authenticity of banknotes, but most of them utilize optical methods.

One example is focusing on a specific part of a pattern printed on a banknote, detecting the reflectance, transmittance, color, etc. at that part, and checking whether the detected value matches the standard value. Alternatively, there is a method of checking whether the pattern when replaced with "0" or "1" signals matches the reference pattern or not. Therefore, in such a method, a reference value or a reference pattern is fixedly set in the device in advance, and the reference value and the detected value or pattern are compared.

However, in the conventional method, the reference values or reference patterns are fixed, so if you want to change the detection location or the pattern of the banknote itself, you have to change these reference values or reference patterns. It is often difficult to change these, and even if they can be changed, the adjustment is extremely troublesome.

Furthermore, the detection device is economically prone to dust and dirt.
Since the luminous intensity of the light emitting part decreases over time, the detection device had to be cleaned and adjusted periodically.

Furthermore, since each detection device has variations, its adjustment is extremely troublesome. The present invention has been made based on the above-mentioned problems, and a standard bank note is prepared in advance, and a printed pattern of the standard bank note is detected by a detector for detecting the bank note to be discriminated, and the detection signal is is stored in the standard signal storage device, and when the banknotes to be determined are to be discriminated, the printing pattern of the banknotes to be determined is detected by the detector, and this detection signal and the standard bank stored in the reference signal storage device are detected. It is an object of the present invention to provide a bank note discriminating device that can accurately discriminate the type and authenticity of a bank note by comparing the detection signal with the note detection signal.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 6.

The device of the present invention includes a detection section and a signal processing section. In the figure,
21a, 21b and 21'a, 21'b are conveyor belts disposed facing each other, 22a, 22b and 22
'a, 22'b are rotating rollers for driving each belt, and the banknote a is rotated by the belts 21a, 21b and 22'b.
It is held between 1'a and 21'b and conveyed in the direction of the arrow.
An illumination unit 26 comprising an illumination light source 23, a condensing lens 24, and a transparent guide 25 functioning as a slit uniformly illuminates a predetermined area in the width direction of the banknote a being conveyed. In contrast to the lighting unit 26, the light receiving unit 27 is composed of a diffusion plate/guide plate 28 and a plurality of light receivers 29, 29', 29'', . . . that convert the amount of received light into an amount of electricity, The light transmitted through the bank note a is uniformly received by the plurality of light receivers 29, 29', 29'', . . . . In this case, each light receiver has a different wavelength sensitivity and receives transmitted light in multiple bands. An example of the wavelength sensitivity of each receiver when the number of receivers is three, for example, is shown in the third example.
As shown in the figure. In FIG. 3, curve A represents the first light receiver 29.
Curves B and C show the spectral sensitivities of the second and third photoreceivers 29' and 29'', respectively.The photoreceptors with these spectral sensitivities are, for example, silicon photodiodes with suitable colors. This can be easily realized by combining glass filters. Figures 4 to 6 are diagrams showing the relationship between the illumination and light receiving areas and the running position of the banknote.

In this figure, a is a banknote, 30 is an illumination and light receiving area, that is, a transparent guide 25 and a diffuser plate 2 in FIG. 2a.
8 areas are shown. In this figure, the banknote a is conveyed in the direction of the arrow across the illumination and light-receiving area 30, but the area 3
The width W of 0 is set as wide as necessary. By doing so, it is possible to eliminate the influence of shift or skew in the conveyance position of the banknote a. Also, the length L of the region 30
By making .times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..times..

In this way, when the banknote a passes through the area 30 and the transmitted light is received by the plurality of light receivers, the light receiver output is sent to the signal processing section.

Therefore, the signal processing section will be explained with reference to FIG. 2b. The electrical signals obtained by the photodetectors 29, 29', 29''... are sent to the front layer amplifiers 31, 31', 31'', respectively.
. . . are amplified to appropriate zero-bell voltage signals, resulting in signals 32, 32', 32, . These signals then go to integrators 33, 33', 33...
added to. Further, 34 is a photo switch which detects the leading edge of the bank note a being conveyed and generates a leading edge signal 35. This signal 35 is sent to a timing circuit 36, which receives this signal 35 and generates a timing signal for controlling the integration timing of each integrator. The integration time is the time from when the bank note a reaches the illumination and light receiving area 30 to when it completely passes through it. In this way, the signals integrated by each integrator for a predetermined time are Vo, V2, V3.
It is...

The signals V,, V5, and V3 are then sent to an adder 3, which is an adding means.
7, and the adder 37 adds the signals V, , V2, and V3 and outputs the signal Y. A divider 38 serving as a dividing means divides the signal V by the signal Y to obtain a signal v, and a divider 38' divides the signal V2 by the signal Y to obtain a signal v2.
When the signals v,, v2... are obtained in this way, these signals v,, v2..., Y are then stored as electrical quantities and compared with the reference signal to determine the type. Comparator 391A, 39 which is a discrimination circuit, that is, a comparison means
'-A, 39''-A...and 39-B, 39'-B,
39''-B..., this comparator 39-A, 39'
-A, 39''-A... A memory device, for example, a reference voltage setting circuit 40, stores the reference amount of electricity preset for each type of normal bank note.
-A, 40'-A, 40r-A... and 40-B, 4
It is designed to be compared with each reference voltage from 0'-B, 40^-B, . . . .

That is, the reference voltage setting circuits 40-A, 40'-A, 4
0″-A...and 40-B, 40'-B, 40〆-B
Each of the reference voltages set in .

Therefore, the comparator 39-A... and the reference voltage setting circuit 40-A... are used, for example, in the case of a type A bank note, and the comparator 39-B... and the reference voltage setting circuit 40-A... By installing a plurality of circuits 40-B as in the case of type B banknotes, the type of banknote can be determined. (See Figure 2b) The reason for calculating the ratio of each band's output after multi-band straining as described above is due to local dirt, damage, overall dirt, and changes in conveyance speed of banknotes. This is to remove the influence. In other words, in addition to partial damage and stains, securities, etc., can become dirty throughout the distribution process, and if we consider unused banknotes as a standard, those that have been used for a long time will have less light penetration throughout. The rate decreases to about 70% to 65%. This fact means that it is not possible to make a correct determination simply by detecting the amount of transmitted light, but this problem can be solved by making a determination using the relative value of the multiband output as described above. Furthermore, since the signals v,, v2 are completely unrelated to the conveyance speed, the comparators 39-A, 39-B... and 39-B. ...
The allowable value of the comparison limit for ... can be minimized.

Each comparator compares the input signal and the reference signal and outputs a signal "1" if the difference between the two is within a predetermined range, and outputs a signal "0" if it is outside the range.

Each of these outputs is then applied to AND circuits 41 and 42, which are determining means, and if the AND condition is satisfied, the output Vo becomes "1" and it is determined that the banknote under test is normal, and Vo is "0'', the bank note is determined to be abnormal. In one embodiment of the present invention, an integrated value is set and stored as a reference voltage as a reference quantity of electricity in various banknotes, but the invention is not necessarily limited to this. For example, the reference waveform can be set as a pattern waveform. You may also set it as is and compare it.

Now, regarding a certain standard banknote, the outputs of the light receiving system in three bands are V,,V2,V3, and the fluctuation rate of transmittance of each band of an arbitrary banknote is K,,K2,K3, respectively. Then, Y=K, V, 10K2V20K3V3 v, =K, V, /Y v2ヱK2V2/Y.

Except in special cases, almost no spectral deviation is observed even if the transmittance changes due to overall dirt. That is,
K, K2, K3=K except in special cases. Therefore, each value above becomes as follows. Y NiK (V, 10V
20V3)=KY.

v, niKV, /KY.

=vo, V2=KV2/KY.

However, Yo, vo, vo2 are values related to the standard bank note.

Therefore, since v,, v2 are values from which fluctuation factors that occur during the distribution process are removed, the variation in detected values is small, and a narrow tolerance range can be set, allowing highly accurate identification. In the above equation, the three outputs V,,V2,V
Divide each individual output by the addition value Y of 3 to obtain the output v. , v2, the overflow of the divider (when the numerator is larger than the denominator) is completely prevented. When there are no hard constraints such as divider overflow, v′,=
A similar effect can be obtained by determining the output ratio using V, /V3, v'2=V2/V3, etc., and making the determination based on v', , v'2, V3. As explained above, the present invention prepares standard banknotes in advance, detects the printing pattern of the standard banknotes using a detector for detecting banknotes to be discriminated, and converts the detection signal into a reference signal. The detection signal is stored in a storage device, and when the banknote to be determined is discriminated, the print pattern of the banknote to be determined is detected by the detector, and this detection signal and the reference signal are used to detect a standard banknote stored in the storage device. The type and authenticity of banknotes can be determined by comparing them with signals.

Therefore, when the detection output decreases because dust or dirt adheres to the detector or the luminous intensity of the light emitter decreases, the reference amount at the time of the output decrease is stored again in the reference amount storage device using a normal bank note. It only needs to be adjusted, and no further adjustment is required.

Furthermore, even when the detection location is changed or the pattern of the bank note changes, the reference amount can be obtained by simply passing a normal bank note through the system, so there is no need for adjustment, which is a special effect.

In the above-described embodiments, the case where the transmitted light of the bank note is photoelectrically converted has been described, but the present invention is not limited to this, and the reflected light may be photoelectrically converted.

Furthermore, in the embodiment shown in the second figure, the signal v is obtained by taking the ratio of the signal Y and the signal V, and the signal v2 is obtained by taking the ratio of the signal Y and the signal V2, and these signals v,, v2, and Y are obtained by taking the ratio of the signal Y and the signal V2. The output signals from each comparator were led to a comparator, and the output signals from each comparator were ANDed, which was used as the discrimination result.As a result of the experiment, the signal Y was the signal v
,,Since it became clear that there was not much difference from the reference value for the banknote pattern compared to v2, the output signals of the comparators 39''-A and 39''-B were not added to the AND circuit 41. Furthermore, even if the judgment result is obtained only from the ratio of signal V to signal Y, that is, signal v, it is possible to accurately distinguish between pseudo banknotes with almost the same pattern as normal banknotes. can be excluded. BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Vertical sectional view of an automatic teller machine showing an embodiment, FIGS. 2a and b
3 shows an embodiment of the configuration according to the present invention, in which a is a perspective view of a detection section, b is a block diagram of a signal processing section, and FIG. 3 is a diagram showing spectral characteristics of a plurality of light receivers used in the discrimination device. , and FIGS. 4 to 6 are diagrams for explaining the relationship between the conveyance state of banknotes and the irradiation area in the same apparatus.

a...Bank note, 21a, 21b, 21'a, 2
1'b...Transport belt, 26...Lighting unit, 27.
...Light receiving unit, 29, 29', 29''...
・Receiver, 40-A, 40'-A, 40''-A,...
…, 40-B, 40′-B, 40″-B, “””””M
Memory device (reference voltage setting circuit), 39-A, 39'-A
,39''-A,...,39-B,39'-B,39''-
B...Discrimination circuit (comparator).

Figure 1 Figure 3 Figure 4 Figure 2 Figure 5 Figure 6

Claims (1)

[Claims] 1. In a device that optically detects the printing pattern of a banknote to identify the banknote, a light source that illuminates the banknote during transport and a light source that illuminates the banknote according to the print pattern from the banknote that is irradiated by this light source. A plurality of light receivers that receive transmitted light, a plurality of integrators that integrate electrical signals obtained by these light receivers, an adding means that adds the outputs of these integrators, and a a dividing means for dividing the output of each integrator by the output; a reference signal storage for storing a reference signal corresponding to a printing pattern in the case of a standard banknote; and a comparison means for comparing with a reference signal, and the reference signal storage device is configured to store, as the reference signal, a signal received by the light receiver from a bank note to be used as a standard at the time of discrimination. banknote identification device.