JPS6027439B2 - Banknote identification device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a banknote discrimination device for discriminating the types of a plurality of banknotes conveyed in an automatic transaction 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 are being 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. Furthermore, there is a demand for an improved automatic teller machine of the one-shot deposit type shown in FIG. That is, in FIG. 1, a deposit port 4 consisting of a rotatable cover 2 and a storage box 3 is provided on the front of the body 1, and a customer deposits banknotes a into the storage box 3.・It is designed to be put in all at once while standing. The rear of the storage box 3 is constructed by a pulley 5 and an inorganic annular belt 6, which sequentially pass the inserted banknotes a one by one. A take-in rotor 8 is provided for taking in the material into 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 in the counterclockwise direction 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.
0b, and at this branch point there is provided a dividing gate 11 which can be rotated freely using, for example, a rotary solenoid as a driving source.

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, the banknote is operated to be transferred to the branch conveyance path 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 stacking banknotes a, which is supported by one end of a shaft 14 and 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 provided with the terminal end facing the front of the bonito 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 effect techniques.

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. However, since this method temporarily stops the banknotes in transit and shines light on specific areas during that period, not only does it take a long time to identify them, but the banknotes that are being transported automatically If there is a positional shift or twist as shown in FIG. 6, there will be a positional shift between the detection position (the location where light is irradiated) and the specific location, making accurate discrimination impossible.

Furthermore, according to this method, even if the banknote itself is normal, if there is dirt or wrinkles in the specific areas mentioned above, the banknote is rejected as abnormal because the whole is judged based on the information from only that part. I have a captivating feeling. As described above, the above-mentioned method has the disadvantage that the discrimination accuracy is affected by the conveyance conditions, local dirt on the banknote, and the like. The present invention was made in view of the above-mentioned circumstances, and its purpose is to provide a banknote discriminating device that can correctly discriminate the types of banknotes, regardless of whether they are front or back or how they are folded during transportation. It is something.

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 disappearing direction.
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'', . . ., which convert the amount of received light into an amount of electricity. The light transmitted through a is uniformly received by the plurality of light receivers 29, 29', 29'', . . . . In this case, each photoreceiver has a different wavelength sensitivity and receives transmitted light in multiple bands. FIG. 3 shows an example of the wavelength sensitivity of each light receiver when the number of light receivers is three, for example. In FIG. 3, curve A shows the spectral sensitivity of the first light receiver 29, and curves B and C show the spectral sensitivities of the second and third light receivers 29' and 29'', respectively. The receiver can be easily realized, for example, by combining a silicon photo diode with a suitable colored glass filter. Figures 4 to 6 show the relationship between the illumination and light receiving area and the running position of the banknote. It is a diagram.

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.
... is amplified to an appropriate zero-bell voltage signal,
The signals become signals 32, 32', 32'', . . . These signals are then applied to integrators 33, 33', 33'', . 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 and the circuit 36
receives this signal 35 and generates a timing signal for controlling the integration timing of each integrator. The integral time is banknote a
This is the time from the time when the light reaches the illumination and light receiving area 30 to the time when the light completely passes through. In this way, the signals integrated for a predetermined time by each integrator are V,,V2,V3・
It's ....

The signals V,, V2, and V3 are then sent to an adder 3, which is an adding means.
7, and an adder 37 serving as an adding means receives the signals V, ,
V2 and V3 are added and a signal Y is output. Then, the divider 38, which is a dividing means, divides the signal V by the signal Y, and the divider 38 divides the signal V by the signal Y.
, and the divider 38' divides the signal V2 by the signal Y to obtain the 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 a reference signal to determine the type. Comparators 39-A, 39''-A, 39''-A, and 39-B, 39 which are circuits, that is, comparison means
'-B, 39''-B... On the other hand, normal banknotes are stored in a memory device, such as a reference voltage setting circuit 40-A, which stores the reference amount of electricity set in advance for each type. , 40'-A, 40''-A...and 4
01B, 40'-B, 40''-B, . . . are provided and are compared with each of these reference voltages.

That is, the reference voltage setting circuits 40-A, 40'-A, 4
0''-A...and 401B, 40'1B, 40''-B
The reference voltages set in . . . are determined in advance by passing normal banknotes through the system of the present invention.

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... By installing a plurality of reference voltage setting circuits 40-B, etc., as in the case of B-type 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. Rate is 70% ~
It decreases to about 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, the signal v,,v2
is completely unrelated to the conveyance speed, so the comparator 391A・
...and 39-B. It is possible to minimize the allowable value of the comparison limit in ....

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'', it is determined that the banknote under test is not normal. Note that in one embodiment of the present invention, a reference voltage is set and stored in advance as the reference electricity quantity for various banknotes, but the invention is not necessarily limited to this; for example, a reference waveform may be set and compared. You can do it like this.

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, 10K2V2 10K3V3 v,=K,V,/Y v2=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. Y2K (V, 10V
20V3)=KY.

V・三KVIノKY.

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
Since the outputs v, , v2 are obtained by dividing each output by the addition value Y of 3, overflow of the divider (when the numerator becomes 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, v2'=V2/V3, etc., and making the determination based on v, , v2', V3. As explained above, according to the present invention, the time required for discrimination is short, and it is resistant to misalignment and local stains during transportation, and it is also easy to produce fake banknotes made with the same pattern by a copying machine etc. can be determined.

Further, it is possible to minimize the allowable value of the comparison limit in the comparator, and it is also possible to improve the discrimination accuracy. In the above embodiment, a case has been described in which light transmitted through a banknote is photoelectrically converted, but the present invention is not limited to this, and reflected light may be photoelectrically converted.

Further, in the embodiment shown in the second figure, the ratio between the signal Y and the signal V is taken to obtain the signal v, and the ratio between the signal Y and the signal V2 is taken to obtain the signal v2, and these signals v,,v2, Y is led to each comparator, and the output signals from each comparator are ANDed, which is used as the discrimination result.As a result of the experiment, the signal Y is 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. Highly accurate discrimination can be made even if the

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an automatic teller machine showing an embodiment of the present invention, and FIGS. 2 a and 2 b show an embodiment of the structure of the present invention, where a is a perspective view of the detection section and b is a perspective view of the detection section. A block diagram of the signal processing section, FIG. 3 is a diagram showing the spectral characteristics of a plurality of light receivers used in the discriminating device of the present invention, and FIGS. FIG. a...Bank note, 21a, 21b, 21'a, 2
1'b...Transport belt, 26...Lighting unit, 2
7... Light receiving unit, 29, 29', 29''...
...Receiver, 40-A, 40'-A, 40''-A, 4
01B, 40'-B, 40''-B... Memory device (reference voltage setting circuit), 391A, 39'-A, 39''
-A, 39-B, 39'-B, 39''-B...
Discrimination circuit (comparator). Figure 3 Figure 1 Figure 4 Figure 2 Figure 5 Figure 6

Claims (1)

[Claims] 1. A conveying means for taking out and conveying banknotes one by one, a light source for illuminating the banknotes being conveyed, and receiving a plurality of different colors of light from the banknotes illuminated by the light source. A plurality of light receivers, a plurality of integrators that respectively integrate the electrical signals obtained by these light receivers, an adding means that adds the outputs of these integrators, and each A dividing means for dividing the output of the integrator, a storage means for storing a reference signal for each color in the case of a reference banknote for each type of banknote, and an output signal for each color from the dividing means. and comparison means for comparing the reference signal for each color of each banknote stored in the storage means, and the type of banknote is determined only when all the color signals match the respective reference signals by these comparison means. A banknote discriminating device comprising a discriminating means for discriminating a banknote.