JPH0745814Y2 - Paper sheet identification device - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention: (Industrial field of application) The present invention is a paper used for a paper sheet processor that reliably detects a security thread provided in the paper sheet. The present invention relates to a leaf identification device.

(Prior art) In order to prevent forgery of paper sheets such as banknotes and checks, and to easily detect counterfeit paper sheets, a strip called a security thread (safety line) is put in the paper. Buried recently. A metal piece such as aluminum or a resin piece such as polyethylene is generally used for this security thread.

Conventionally, the following three methods are mainly known as methods for detecting such a security thread. First, the first detection method is a method of irradiating a banknote with visible light, detecting reflected light and transmitted light thereof, and detecting a security thread by a combination of respective values thereof. The second detection method is the method described in Japanese Patent Laid-Open No. 61-72387. In the case of a security thread using a metal piece such as aluminum, its conductivity is used to cause eddy current loss. This is a method to detect the security thread by the change of the magnetic field.

The third detection method is the method previously proposed by the present applicant and described in Japanese Patent Application Laid-Open No. 63-301393. That is, this detection method is provided with a pair of transmitting antenna and receiving antenna facing each other so as to sandwich the conveyed paper sheet,
The security thread is detected by observing the reflection and absorption of the radio wave emitted from the transmitting antenna by the security thread by the receiving antenna.

(Problems to be Solved by the Invention) Although there are three types of detection methods as described above, the first method is to first detect reflected light and transmitted light of the irradiated visible light and detect them by a combination of their respective values. Then, for example, if the pattern printed on the surface of the banknote is dark, the same reaction as that of the security thread is exhibited, and there is a problem that the security thread is erroneously recognized. In the second method of detecting the change in the magnetic field by utilizing the conductivity of the security thread, since the sensitivity is relatively low, the false detection is likely to occur due to the influence of the external noise. There is a problem that it has to be designed into. Moreover, there is a problem that only a metal sensitive to magnetism can be used as the security thread. Next, the third method of detecting a security thread using high frequency radio waves is more complicated than other methods because radio waves are used, and the transmitter and the receiver are redundant with the transmitting antenna and the receiving antenna. There are problems that need to be solved.

The present invention has been made in view of the above circumstances, and reliably detects the security thread regardless of the material of the security thread with a simple configuration without being affected by the design or pattern of the paper sheet. An object of the present invention is to provide a paper sheet identification device having a security thread detection function that can be performed.

Configuration of Device: (Means for Solving the Problem) This device detects the authenticity of a paper sheet by detecting a security thread provided in the paper sheet such as a banknote.
The present invention relates to a paper sheet identifying apparatus for identifying a type, and the above object of the present invention is to provide a pulse signal generating means for generating a pulse signal having a constant repetition period; A conveying means for moving the paper sheets by a predetermined distance; a light emitter provided on the conveying path for irradiating the conveyed paper sheets with invisible light; and a light emitting device for emitting the invisible light from the light emitter. A transmissive sensor including a light receiver that receives light through the leaves; and a number of pulses from the pulse signal generating means between a plurality of trigger signals generated by differentiating the detection signal of the transmissive sensor and generating the differentiated signal. It is achieved by providing a counting means for counting, and a determination means for comparing and collating each count value counted by the counting means with a predetermined value.

(Operation) In this invention, by irradiating a paper sheet having a security thread with invisible light such as infrared light, the security thread can be surely detected regardless of the stain or material of the paper sheet. There is. As a result, a paper sheet identification device that does not malfunction and has a simple configuration is realized.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 (A) and 1 (B) show an example of a banknote 10 having a security thread 11 according to the present invention. As shown in FIG. 1 (A), the security thread 11 is embedded vertically inside the banknote 10 in the longitudinal direction. The security thread 11 is formed of a metal piece such as aluminum or a resin piece such as polyethylene. And its width is usually 0.5-1.0
In mm, the length is the same as the width of the bill 10.

FIG. 2 is a schematic view showing the structure of a security sled detection device according to the present invention, in which a pair of upper and lower first conveying rollers 20, 21 and second conveying rollers 22, 23 are provided. Transport belts 24 and 25 for transporting are respectively wound between 22 and 21 and 23. The banknote 10 is sandwiched between the conveyor belts 24 and 25, and the banknote 10 is taken in and returned and conveyed, and light is emitted between the first conveyor rollers 20 and 22 and the second conveyor rollers 21 and 23. A transmissive sensor 30 (30A, 30B) composed of a container 31 and a light receiver 32 is arranged perpendicularly to and parallel to the conveyance direction of the banknote 10.
A slit 33, which is narrower than the width of the security thread 11, is arranged on the 32 side. The light receiver 31 of the transmissive sensor 30 emits infrared light, and the light receiver 32 receives and detects light of the infrared light wavelength through the slit 33. Therefore, when the banknote 10 is inserted through the insertion slot, the banknote 10 is nipped and conveyed by the conveyor belts 24 and 25 and taken in, and the banknote 10 is transmitted through the transparent sensor 30 (30A, 30A,
30B), the light emitted from the light emitter 31 passes through the banknote 1
Through 0 and slit 33, the light receiver 32 is shown in FIG.
The detection areas 12A and 12B are used for detection.

By the way, the visible light generally used for the optical sensor is the banknote 10
Strongly affected by the shading of the security thread 11
Also has a detection signal similar to that of the dark part of the banknote 10, but the infrared light is not significantly affected by the density of the banknote 10, and the change of the detection signal due to the density is small. On the other hand, since the security thread 11 is made of a metal piece or a resin piece, it completely blocks even infrared light. Therefore, only the security thread 11 can be extracted and detected.

Next, the security thread 11 of the banknote 10 is detected and the banknote
The third block diagram of the bill validator for discriminating the authenticity of 11
It will be described with reference to the drawings.

The detection signal of the transmissive sensor 30A that detects the detection area 12A of the banknote 10 passes through the amplifier 50 and becomes the detection signal DTA, which is the differentiation circuit 5
The differential signal DFA is input to the waveform shaping circuit 52. Further, the detection signal of the transmissive sensor 30B that detects the detection area 12B of the banknote 10 is sent to the detection signal DTB via the amplifier 53.
Is input to the differentiating circuit 54, and the differential signal DFB is input to the waveform shaping circuit 55. The signal WA that has been waveform-shaped by the waveform shaping circuit 52 is input to the arithmetic control unit 40, is also input to the counter 56 as a reset signal, and the signal WB that is waveform shaped by the waveform shaping circuit 55 is input to the arithmetic control unit 40. At the same time, it is input to the counter 57 as a reset signal. The arithmetic control unit 40 is composed of a CPU 41, a ROM 42, a RAM 43, a bus line 44, etc., and outputs a carrier pulse CP of a predetermined cycle to a controller.
The conveying means 60 is driven via 61. The conveying means 60 rotationally drives the conveying rollers 20 to 23 and conveys the conveying pulse.
CP is counted by counters 56 and 57, and the count value is stored in RAM43.
Is stored in a predetermined area.

In such a configuration, first, the detection signals of the light receivers of the transmission type sensors 30A and 30B, which are provided in parallel on the conveyance path using infrared light as a medium, are input to the amplifiers 50 and 53, respectively, to a level at which signal processing is easy. Is amplified. An example of this amplified signal is shown in FIG. 4 (A). As shown in FIG.
When there is no signal, the detection signal from the receiver is saturated (ST shown)
However, when the bill 10 is conveyed and detected, the amount of light received by the light receiver decreases and the detection level becomes low (DL in the figure). However, since the absorptance of infrared light does not change much depending on the shade of the banknote 10, the amount of transmitted infrared light due to the shade does not change much. Therefore, the change in the detection level due to the pattern of the bill 10 is small, and the detection level of the bill 10 is almost constant. However, the portion of the security thread 11 is almost completely blocked even with infrared light, so that the amount of received light is almost gone and the detection level is low, and a signal like SS in FIG. 4 (A) is obtained. The outputs DTA and DTB from the amplifiers 51 and 54 are sent to the differentiating circuits 51 and 54, respectively, and an example of signals differentiated by the differentiating circuit 51 or 54 is shown in FIG. 4 (B). The signal DFA or DFB differentiated as shown in FIG. 4 (B) generates negative triggers at the time t1 when the bill 10 is detected and at the time t2 when the security thread 11 is detected. Positive triggers are generated at the time point t3 when the bill has passed and the time point t4 when the bill 10 has passed. Then, the signals DFA and DFB differentiated by the differentiating circuits 51 and 54 are input to the waveform shaping circuits 52 and 55, respectively, and the respective waveform shaped signals WA and WB are triggered by the positive or negative triggers of the counters 56 and 57. Each is input to a reset terminal R to be reset, and the arithmetic control unit 40
Connected to bus line 44 of. Also, the counter 56 and
The carrier pulse CP as shown in FIG. 4 (C) synchronized with the driving pulse of the stepping motor, which is the driving unit of the carrier means 60, is input to 57, and this carrier pulse CP is on the other hand the arithmetic control unit. Transport means 60 from 40 through controller 61
The banknotes 10 are fed by a predetermined distance corresponding to one pulse. Therefore, the counter 56
By counting the number of conveyance pulses CP, 57 and 57 can know the conveyance distance of the bill 10.

More specifically with reference to FIGS. 4 (B) and 4 (C), the first trigger is generated at time t1 when the transmissive sensor 30A (or 30B) detects the banknote 10, and the reset terminal of the counter 56 (or 57). It is input to R and the count of the counter 56 (or 57) is reset. Then, as the bill 10 is conveyed, the conveyance pulse CP input to the counter 56 (or 57) is counted.
56 (or 57) counts and counter 56 (or 57)
The count value of is always stored in a predetermined area of the RAM 43.
Then, the bill 10 is further conveyed and the transmissive sensor 30A (or 3
0B) detects security thread 11 (time t
2) The second trigger is generated from the differentiating circuit 51 (or 54). The second trigger is input to the reset terminal R of the counter 56 (or 57) and also to the arithmetic control unit 40,
While resetting the count value of the counter 56 (or 57),
In the arithmetic control unit 40, the count value X of the counter 56 (or 57) stored in the RAM 43 immediately before the second trigger is input
Is the distance from the front edge of the banknote 10 to the security thread 11 for each sensor in a predetermined area of the RAM 43 as X _A , X _B.
Memorize as. Then, at the time t3 when the security thread 11 finishes passing the transmissive sensor 30A (or 30B), the third thread is reached.
When the trigger is generated, the same operation is performed, the count value Z corresponding to the width of the security thread 11 is obtained for each sensor, and stored in a predetermined area of the RAM 43 as Z _A and Z _B. Further, the same operation is performed for the fourth trigger that occurs at the time (t4) when the bill 10 has passed through the transmissive sensor 30A (or 30B), and from the security thread 11 to the rear end of the bill 10. the count value Y that corresponds to the distance determined for each sensor and stored in a predetermined area of the RAM 43 Y _a, as Y _B.

From the above, the count value from the front end of the banknote 10 to the security thread 11 corresponding to each of the transmissive sensors 30A and 30B
X _A , X _B and the count value Z _A , Z _B of the width of the security thread 11
Then, the count values Y _A and Y _B from the security thread 11 to the rear end of the bill 10 are obtained. Then, the unique values X _O , Y _O , and Z _{O of the} authentic banknote stored in advance in the ROM 42 are compared and compared with the obtained count values X _A , X _B , Y _A , Y _B , Z _A , and Z _B. By doing so, the authenticity of the banknote 10 is determined. That is, X _A = X _B = X _O , Y _A =
Truth can be determined by whether or not all the relations of Y _B = Y _O and Z _A = Z _B = Z _O are established. The unique value stored in ROM 42 in advance
X _O , Y _O , and Z _O may have an allowable range.

Incidentally, if the direction to be inserted in the bill may be _{either, X A = X B = X} O, Y A = Y B = Y O, Z A = Z B = Z O or X _A = X _B =
_{Y O, Y A = Y B} = X O, Z A = Z B = any relationship Z _O may be so determined as authentic bill if satisfied. Alternatively, the unique values X _O , Y _O , and Z _O may be stored in advance for each banknote type, and the banknote type may be determined by collating with the calculated count value. Further, although infrared light is used as the invisible light in the above, similar results can be obtained even with ultraviolet light. Furthermore, in the above embodiment, the arithmetic control unit 40
It is designed to be transported based on the carrier pulse CP of
As shown in FIG. 5, a means for generating a pulse signal according to the rotation of the motor 62 may be provided on the side of the conveying means, and the pulse signal may be counted by the counting means. That is, a disc 63 having a predetermined number of teeth is attached to the rotation shaft of the motor 62,
A magnetizing means 64 for magnetizing the teeth of the disk 63 is provided in the vicinity. A magnetic sensor 65 is provided near the disk 63, and the magnetic sensor 65 outputs a pulse signal corresponding to the teeth of the disk 63 in accordance with the rotation of the disk 63.

As described above, according to the paper sheet identification apparatus of the present invention, the security thread of the paper sheet is irradiated with the invisible infrared light or the like to make a determination. Security threads can be detected without being affected by surface stains or materials. This makes it possible to identify the paper sheets with high safety.

[Brief description of drawings]

FIG. 1 (A) is a plan view showing an example of a bill, FIG. 1 (B) is a side view thereof, FIG. 2 is a structural view of the invention, and FIG. 3 is a block diagram showing an embodiment of the invention. FIG. 4 (A)-
(C) is a time chart showing an example of the operation, and FIG. 5 is another structural diagram of the present invention. 10 ... Banknote, 11 ... Security thread, 20-23 ... Conveying rollers, 30, 30A, 30B ... Transmissive sensor, 40 ... Arithmetic control unit, 41
... CPU, 42 ... ROM, 43 ... RAM, 56, 57 ... Counter, 60 ... Conveying means.

Claims (1)

[Scope of utility model registration request] 1. A paper sheet discriminating apparatus for discriminating the authenticity / type of a paper sheet by detecting a security thread provided in the paper sheet, wherein a pulse signal having a constant repetition period is generated. Pulse signal generating means; conveying means for moving the paper sheets by a predetermined distance on the conveying path for each pulse signal from the pulse signal generating means; and paper sheets provided on the conveying path and being conveyed. A transmissive sensor including a light emitter that emits invisible light and a light receiver that receives the invisible light from the light emitter through the paper sheet; and a differential processing of a detection signal of the transmissive sensor, which is differentiated. Counting means for counting the number of pulses from the pulse signal generating means between a plurality of trigger signals generated in the generated signal;
A sheet discriminating apparatus comprising: a discriminating unit that compares and collates each count value counted by the counting unit with a predetermined value.