JPH08287312A - Security thread detecting device for paper sheet - Google Patents

Abstract

PURPOSE: To easily detect whether or not a paper sheet, etc., has an uneven security thread by detecting the thickness of the conveyed paper sheet, etc., by a paper sheet thickness detecting means. CONSTITUTION: Of the paper thickness detecting mechanism, a detection lever 7 rotates on the principle of a lever having its fulcrum on a shaft 4, and when a bill 1 passes, a detection roller 20A pushes the rear end of the detection lever 7 as shown by B so that the tip moves reversely as shown by C, so the distance between the magnetic body 10 at the tip part of the detection lever 7 and a magnetic sensor 30 varies. The output signal of the magnetic sensor 30 based upon the variation is inputted after signal processing to detect the thickness of the bill 1. This thickness detecting mechanism can detect the uneven security thread judging from variation of the output signal of the magnetic sensor 30 since the output signal varies periodically according to the unevenness of the uneven security thread woven into the bill 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a security thread detecting device for paper sheets such as banknotes, and more particularly, it simply detects whether or not the uneven security thread woven in the paper sheets is woven in the paper sheets. The present invention relates to a security thread detecting device for paper sheets, and also relates to a security thread detecting device for paper sheets that does not reject a paper sheet in which the uneven security thread is woven as an abnormal thickness. It is a thing.

[0002]

2. Description of the Related Art Conventionally, in the case of detecting paper sheets such as banknotes having two sheets overlapped with each other or tapes attached thereto and having an abnormal thickness, rollers or the like generally arranged in a conveying path are used. The displacement from the reference position is detected by an optical or magnetic means. However, the roller interval of such a detection device is adjusted in advance so that it will not be displaced even if only one sheet of paper is conveyed, but such roller interval adjustment is not easy, and the roller interval is always constant. Without adjustment, accurate thickness abnormality could not be detected. Further, in order to detect the duplication of two sheets, the displacement amount is detected according to the thickness of the conveyed sheet, and when the displacement amount exceeds a preset threshold (allowable range), the sheet is detected. When it is detected that two sheets of paper are overlapped with each other, for example, when a thin tape or the like is attached to the paper sheet, it is detected by the mutual relationship between the thickness of the banknote, the thickness of the tape, and the setting of the threshold range. It was impossible.

Therefore, as disclosed in Japanese Unexamined Patent Publication No. 1-127540, the thickness of a paper sheet is not determined by a threshold fixed to a constant value, but the paper sheet is conveyed every time it is conveyed. The thickness of a class is estimated, and a fixed value is added or multiplied to the estimated thickness to determine the threshold, and whether or not the detection signal exceeds this threshold is determined, or the amount of excess is determined. It has been proposed to detect an abnormality of a paper sheet so that even if an extremely thin abnormal object such as a tape is attached to the paper sheet, the abnormality can be surely detected.

[0004]

However, in recent years, there are some foreign banknotes in which fine fibrous ones called security threads are woven at the time of coining as a counterfeit prevention measure. There are various types of these banknotes,
In many cases, it is not possible to know whether or not a security thread is included without looking at the watermark, but a device for detecting the presence or absence of these security threads is generally complicated.
And recently, in England, Germany, etc., uneven security threads are woven into banknotes, and the convex parts are partially and repeatedly appearing on the surface of the banknote, so that banknotes that can be easily visually confirmed have appeared. are doing. FIG. 2 is a plan view of the banknote 1 in which the uneven security thread 1A is woven, and FIG. 3 shows a partial cross-sectional structure of the AA part, in which the convex portion of the uneven security thread 1A is the surface of the banknote 1. Repeatedly protruding above.

When these banknotes 1 are detected by the above-mentioned conventional abnormality detecting device, the height of the convex portion projecting on the surface of the banknote 1 is detected as the thickness of the banknote 1, and therefore it is judged as a thickness abnormality and rejected. Will be done. Further, at present, no device for detecting the uneven security thread has appeared. In some cases, there is also a demand for a device that simply detects whether or not the uneven security thread is included in a paper sheet. For example, when all bills are replaced with such threaded ones, it is desired to distinguish between those containing the thread and those not containing the thread by an automatic processor.

The present invention has been made under the circumstances as described above, and an object of the present invention is to detect a security thread for paper sheets, which is adapted to detect the presence / absence of the uneven security thread woven in the paper sheets. To provide
Another object of the present invention is to provide a security thread detecting device for a paper sheet, which detects the uneven security thread woven in the paper sheet and prevents the paper sheet from being rejected due to the uneven security thread. .

[0007]

SUMMARY OF THE INVENTION The present invention relates to a security thread detecting device for paper sheets such as banknotes, and the above object of the present invention is to detect a thickness of a conveyed paper sheet, and a thickness detecting means for detecting the thickness. And a security thread detecting means for detecting the security thread woven in the paper sheet according to the change in the thickness of the paper sheet detected by the means. Further, the thickness detecting means for detecting the thickness of the conveyed paper sheet according to the conveyance, and the uneven security thread woven into the paper sheet are detected by the change in the thickness of the paper sheet detected by the thickness detecting means. After that, it is more effectively achieved by including a control means for controlling the discrimination of the paper sheets.

[0008]

In the paper sheet security thread detecting device of the present invention, the paper sheet thickness detecting means is adapted to detect the thickness of the conveyed paper sheet. When replaced with a woven one, one that does not include the rugged security thread can be rejected by an automated processor. Further, the control means detects the uneven security thread woven into the paper sheet to control the identification of the paper sheet, and after the uneven security thread is detected by the thickness detecting means, the paper sheet is detected as an abnormal thickness bill. The kind prevents it from being rejected.

[0009]

1 shows a mechanical schematic structure of a security thread detecting device according to the present invention. The thickness detecting means for detecting the thickness of a paper sheet 1 such as a bill is a thickness of the bill 1 conveyed in the A direction. Is continuously detected. The banknote thickness detecting means is provided with a first transfer device 11 and a second transfer device 20 for transferring a banknote inserted from an insertion port (not shown) or a banknote 1 from a storage section (not shown). Each of them is sandwiched between a pair of upper and lower conveyor belt mechanisms and continuously conveyed one by one in the A direction. A pair of upper and lower detection rollers 20A and 20B are provided between the first conveyance device 11 and the second conveyance device 20, and these detection rollers 20A and 20B are shown in FIGS.
5 as an embodiment of the present invention, and FIG. 6 as a third embodiment of the present invention, the bill thickness detection mechanism whose principle is shown in FIG. 6 is connected, and the bill thickness detection mechanism detects the thickness of the bill 1 being conveyed. Has become.

FIG. 4 showing the first embodiment shows the operating principle of the bill thickness detecting mechanism, in which the upper detecting roller 20B is fixed in position and the lower detecting roller 20A is vertically movable. In FIG. 4A, the banknote 1 has rollers 20A and 20A.
It is in a standby state where it has not passed between B, and at this time, the magnetic body 10 such as a hexagonal bolt and the magnetic sensor 30 such as a differential transformer type magnetic head mounted on the tip of the detection lever 7 are fixed as shown in the figure. The positional relationship is maintained at a distance of.

In FIG. 1B, the bill 1 has rollers 20A and 20A.
It shows the operation of passing between B. In this bill thickness detecting mechanism, the detection lever 7 rotates on the principle of lever with the shaft 4 as a fulcrum, and when the bill 1 passes, the detection roller 20A moves to the detection lever 7A. Since the rear end is pushed in the B direction and the front end moves in the opposite C direction, the distance between the magnetic body 10 and the magnetic sensor 30 at the front end of the detection lever 7 changes. The thickness of the banknote 1 can be detected by performing signal processing and capturing the output signal of the magnetic sensor 30 due to this change. According to such a thickness detection mechanism, in the uneven security thread 1A woven into the banknote 1, the output signal of the sensor 30 periodically changes according to the unevenness, so that the uneven security thread 1A is detected based on the signal change. be able to.

In FIG. 5 showing the second embodiment, the detection lever 7 is engaged with the detection roller 20A similarly to the first embodiment.
And a magnetic sensor 30 are arranged. In this example, a magnetic material is embedded in the tip of the detection lever 7, and the lever operates with the shaft 4 as a fulcrum. Banknote 1 is roller 20A, 20
In the standby state where the sheet B is not passed, the detection lever 7 and the magnetic sensor 30 maintain a positional relationship with a certain interval as shown in FIG. ), The rear end of the detection lever 7 moves in the B direction by the downward movement of the roller 20A, and the front end moves in the C direction via the fulcrum 4. As a result, the gap between the magnetic sensor 30 embedded in the tip of the detection lever 7 and the magnetic sensor 30 changes, and the thickness of the bill 1 can be detected. or,
Similarly, by disposing the rollers 20A and 20B at the position of the security thread 1A of the bill 1, it is possible to detect the presence or absence of the security thread 1A.

FIGS. 6A and 6B show a third embodiment of the bill thickness detecting mechanism. In FIG. 6A, the bill 1 is a roller 2
0A and 20B have not passed, and the same figure (B) has shown the operation | movement time which the banknote 1 has passed. In this bill thickness detection mechanism, the detection arm 3 operates on the principle of leverage with the shaft 6 as a fulcrum, the lower detection roller 20A is fixed in position, and the upper detection roller 20B is engaged with the spring member 5 and this. It is constantly pressed downward through the detected arm 3.

Here, as shown in FIG. 6 (B), the bill 1 is conveyed to the thickness detecting means and the detecting rollers 20A and 20A are provided.
When passing between 0B, the detection roller 20B is pushed upward by the thickness δ of the bill 1. Therefore, the detection roller 2
The lower end 31 of the detection arm 3 is also pushed up by the thickness δ via the bearing 8 coupled to the shaft of 0B, and this displacement amount (thickness δ) is based on the lever principle of the detection arm 3 with the shaft 6 as a fulcrum. Since the potentiometer arm 2 is enlarged (for example, 5 times) and pressed by the pressing portion 32 at the upper end, the potentiometer arm 2 is rotated by the displacement angle θ, and both the potentiometer and the rotating shaft are rotated by the same displacement angle θ. It has become. Thereby, the thickness of the banknote 1 can be detected, and similarly, it can be applied to the detection of the security thread 1A. Further, basically, the displacement of either the lower side or the upper side of the conveying path is detected by a magnetic change or an electric change, but it may be detected by an optical or electromagnetic change. Good. Further, not only the displacement of the roller on one side of the transport path but also the change of the rollers on both sides may be detected.

FIG. 7 shows a bill thickness detecting mechanism as described above.
By arranging as shown in (A) and (B), the uneven security thread 1A can be detected as the bill 1 is conveyed. That is, the output signals SG1 of the magnetic sensors 30 arranged at both ends are input to the differential amplifier 101 as shown in FIG. 8, and the differential output signals are input to the low-pass filter (LPF) 103 and the band-pass filter (LPF) 103. B
Only the required frequency component is extracted via the PF 104 (S
G2), the extracted signal SG2 is converted into a digital signal by the A / D converter 105, and the RAM3 is transmitted via the CPU 200.
It is supposed to be stored in 00. The ROM 301 stores the program of the CPU 200, necessary reference data, and the like.

When the bill thickness detecting mechanism detects the uneven security thread 1A, the roller 20A or 20B moves up and down according to the unevenness of the security thread 1A, as shown in FIGS. 9 (A) and 9 (B). The signal SG2 is obtained in relation. By inputting such a signal SG2, the CPU 200 can detect the presence or absence of the uneven security thread 1A, and when it is determined that the banknote has the uneven security thread 1A, the CPU 200 does not reject it as an abnormal thickness of the banknote. To do.

In this case, the detection signal SG1 is generated at the front and rear ends of the banknote 1 with respect to the transport direction A by mechanical vibration or the like.
Since a lot of noise is generated in the data, a separate noise prevention measure is taken and the digital amount of the detection signal SG1 (SG2) in the region L excluding both ends is treated as stable data as shown in FIG. 9B. I am trying.

FIG. 10 shows an operation example of the present invention. When the bill 1 is conveyed (step S1), the thickness of the bill 1 is continuously detected by the bill thickness detecting mechanism (step S2). The differential output signal from the magnetic sensor 30 of the bill thickness detecting mechanism or the output signal from the potentiometer is digitized as described above to the RAM 30.
It is stored in 0 (step S3). After this, the CPU 200
Detects the peak (concavo-convex data) based on the detected detection signal of the banknote 1 (step S4), and then determines the presence or absence of the concavo-convex security thread 1A of the banknote 1 from the number of peaks, the cycle of the detection signal, and the like. (Step S5), when it is determined that the uneven security thread 1A is present,
The CPU 200 does not determine that the thickness is abnormal (step S
6). Then, it is determined whether the bill is an abnormal bill based on the thickness or other identification result (step S7), and if it is determined to be an abnormal bill, it is rejected (step S8).
In addition, in step S5, the uneven security thread 1
When it is determined that there is no A, it is determined whether or not to reject based on the identification result such as the thickness.

As another operation example, as a device that simply detects whether or not the uneven security thread is included in a paper sheet, for example, a bill is replaced with one in which the uneven security thread is woven. At this time, when an attempt is made to reject a bill that does not include the uneven security thread by the automatic processor, it is determined that there is no uneven security thread 1A for the bill 1 based on the number of peaks and the detection signal cycle in step S5. If it is judged, it will be rejected. In this example, the case where there is no uneven security thread 1A is rejected.
On the contrary, the case where such a thread is present may be rejected, that is, it is sufficient that the bill can be distinguished by the presence or absence of the uneven security thread.

Although a bill is used as an example, even if such an uneven security thread is woven into paper such as securities, checks, gift certificates, cash vouchers, important documents, etc., it is within the scope of the right of the present case. included.

[0021]

As described above, according to the present invention, the device has a simple structure and can easily detect whether or not the paper sheet includes the uneven security thread. Further, even when paper sheets such as banknotes are woven with uneven security threads, they will not be rejected as abnormal banknotes due to the thickness of the uneven security threads.

[Brief description of drawings]

FIG. 1 is a mechanism diagram showing an example of a bill transporting device to which the present invention can be applied.

FIG. 2 is a plan view of a bill in which uneven security threads are woven.

FIG. 3 is a partial cross-sectional structural view taken along the line AA in FIG.

FIG. 4 is a schematic view showing a first embodiment of a bill thickness detecting mechanism.

FIG. 5 is a schematic view showing a second embodiment of the bill thickness detection mechanism.

FIG. 6 is a schematic view showing a third embodiment of the bill thickness detection mechanism.

FIG. 7 is a diagram showing a manner in which a concave-convex security thread is detected by using a bill thickness detecting unit.

FIG. 8 is a block diagram showing a circuit configuration example of the present invention.

FIG. 9 is a time chart showing an operation example of the present invention.

FIG. 10 is a flowchart showing an operation example of the present invention.

[Explanation of symbols]

 1 banknote 2 potentio arm 3 detection arm 4 axis 7 detection lever 10 magnetic body 11, 20 carrier devices 20A, 20B detection roller 30 magnetic sensor 101 differential amplifier 102 full-wave rectifier 103 LPF 104 BPF 105 A / D converter 200 CPU 300 ROM 301 RAM

Claims (2)

[Claims] 1. A security for detecting a thickness of a sheet to be conveyed, and a security for detecting a security thread woven into the sheet due to a change in the thickness of the sheet detected by the thickness detecting means. A security thread detection device for paper sheets, comprising a thread detection means. 2. A thickness detecting means for detecting the thickness of the conveyed paper sheet according to the conveyance, and an uneven security woven into the paper sheet due to a change in the thickness of the paper sheet detected by the thickness detecting means. A security thread detecting device for a paper sheet, comprising: a control unit for detecting a thread and controlling the identification of the paper sheet.