JP2566959B2 - Security thread detection device for paper processing machine - Google Patents

Description

The present invention relates to a security thread detecting device used in a paper sheet processing machine.

[Conventional technology]

Recently, to prevent counterfeiting of paper sheets such as banknotes and checks, and to facilitate the discovery of counterfeit paper sheets, it has recently been possible to insert a strip called a security thread into the paper. Has been done.

As the security thread, a metal piece such as aluminum or a resin piece such as polyethylene is used to detect the transmitted light and the change of the magnetic field due to the eddy current loss as described in JP-A-61-72387. What is known is.

[Problems to be solved by the invention]

However, such a conventional security thread detection method is not always satisfactory.

That is, the method of detecting transmitted light may cause erroneous detection due to patterns and stains on paper sheets, and cannot distinguish forgery by sticking the same material as the security thread at the same position.

In addition, since the method of detecting changes in the magnetic field has relatively low sensitivity, it is apt to be erroneously detected due to the influence of external noise. Therefore, there is a problem that the detection circuit must be designed with high sensitivity. -Only metal that is sensitive to magnetism can be used as the thread, but there is also a problem that the metal piece is easy to come off especially in a banknote that is tired, and the authenticity is erroneously determined.

The present invention has been made to solve such a problem, and a security thread capable of detecting a security thread of any material with a simple configuration without being affected by the pattern of paper sheets and the like. An object is to provide a detection device.

[Means for solving problems]

According to the first embodiment of the security thread detecting device of the paper sheet processor according to the present invention, the paper sheet is conveyed along the conveying path to the processing section for processing the inserted paper sheet. And a plurality of pairs of wave-transmitting antennas and wave-receiving antennas, which are provided to face each other so as to sandwich the paper sheet to be conveyed, in the middle of the conveying path, and each of which operates separately, Transmitting / receiving means for driving the plurality of wave transmitting antennas with the same high frequency signal, and separately receiving high frequency radio waves emitted from the wave transmitting antennas by the plurality of receiving antennas facing each other; By comparing the detection signal detected by the antenna with a predetermined reference voltage to obtain each detection output,
And a detecting means for detecting the presence of the thread.

Further, the security of the paper sheet processing machine according to the present invention
According to the second embodiment of the sled detection device, a conveying unit that conveys the paper sheet along a conveyance path to a processing unit that processes the inserted paper sheet, and a conveyance unit that conveys the paper sheet in the middle of the conveyance path. Based on the material of the security thread in the paper sheet, the paper sheet is provided with a plurality of pairs of transmitting and receiving antennas, which are provided so as to face each other so as to sandwich the sheet sheet and are operated separately. A transmitting / receiving unit that separately drives a plurality of the transmitting antennas with high-frequency signals having different characteristics, and separately receives the high-frequency radio waves emitted from each of the transmitting antennas with a plurality of opposing receiving antennas. , The security signal in the paper sheet by comparing the detection signal detected by each of the receiving antennas with a predetermined reference voltage to obtain each detection output.
And a detecting means for detecting the presence of the thread.

〔Example〕

An embodiment of a security thread detecting device for a paper sheet processor according to the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing a paper sheet processor to which a security thread detecting device related to the present invention is applied,
A paper sheet storage unit 2 for accumulating and storing paper sheets P in the apparatus main body 1, and a paper sheet P fed out from the paper sheet P group accumulated in the paper sheet storage unit 2 one by one Paper transporting section 3 for transporting
And a paper sheet collection unit 4 that sequentially collects the paper sheets P sent from the paper sheet transport unit 3 and counts them.

As shown in FIG. 1 and FIG. 4, the paper sheet storage unit 2 includes a mounting table 6 that is inclined forward and downward for stacking and mounting the paper sheet P group, and is located above the mounting table 6. The front end 8 of the leaf P is in contact with the front plate 8.
A kicker roller 7 that is rotatably driven in the direction of the arrow in the lower part of the table and has a protruding portion 7A that protrudes on the upper surface of the mounting table 6 and contacts the lowest paper sheet P on a part of the peripheral surface; A feed roller 9 is provided below the mounting table 6 at the lower end position of 8 so as to be rotatable and driven in the direction of the arrow, and a part of the peripheral surface of the feed roller 9 is provided so as to project to the upper surface of the mounting table 6, and is opposed to the feed roller 9. A conveyance guide roller 9A for sending out the paper sheet P, and a gate roller 10 provided opposite to the feed roller 9 for forming a gate interval between the feed roller 9 and only one sheet P can pass through.
The sheet P, which is downstream of the feed roller 9 and has passed through the gate interval, is configured to include a transport roller 11 that transports the sheet P between the transport guide roller 31 and the transport roller 11. Is a light-receiving element 12 that detects the paper sheet P and a receiving antenna 60 that forms a security thread detector.
It has. And guide plate so as to face these
The light emitting element 13 and the wave transmitting antenna 50 are provided in the unit 14.

The paper sheet collecting unit 4 includes a guide plate 15 for guiding the paper sheets P discharged from between the conveying roller 11 and the guide plate 14, an impeller 16 provided so as to cross the guide plate 15, and the blades. It is composed of a stacking plate 17 for accumulating paper sheets P conveyed by a car 16. As is well known, the impeller 16 is a blade 16B made of a thin piece of elastic material such as synthetic resin on the peripheral surface of the drum 16A.
Are planted in the tangential direction at a constant interval, sandwiching the paper sheet P between adjacent blades 16B, and squeezing the paper sheet P from the blade 16B to the stacking sheet 17 when crossing the stacking plate 17. It is designed to accumulate in a standing position.

The guide plate 14 is attached to a frame body 20, and the frame body 20 has an opening / closing cover 19 whose lower portion is pivotally supported by a shaft 18 to open the conveying unit 3, and is fixed to the inner surface of the opening / closing cover 19. . Therefore, the guide plate 14 is opened by opening the opening / closing cover 19. A substantially L-shaped lever 29 is rotatably attached to the guide plate by a shaft 30.
The above-mentioned conveyance guide roller 31 is rotatably attached to one end of the lever 29, and a tension spring 31 is attached to the other end of the lever 29 so that the conveyance guide roller 31 is pressed against the conveyance roller 11. Energize. It should be noted that the guide plate 14 is provided with a notch corresponding to the transport guide roller 31, and the peripheral surface portion of the transport guide roller 31 projects from this notch.

A magnet 41 is provided on the side of the apparatus body 1 where the open / close end of the open / close cover 19 is joined, and the open / close end of the open / close cover 19 is attracted to maintain a closed state.

FIG. 2 is a block diagram showing the overall configuration of a paper sheet processing apparatus including a security thread detecting apparatus related to the present invention.

According to the figure, a security thread detection circuit 200 for detecting the presence of a security thread, a counting sensor 300 for counting the number of sheets, and an operation unit 400 such as a start / stop switch and a clear switch are provided. The outputs of these are input to the control unit 100. The control unit 100 performs arithmetic processing according to a predetermined procedure, causes the counting unit 900 to perform a counting operation, and causes the transport driving unit 800 to switch the transport path when the security thread is not detected, and the rejection unit. Drive 700 to eject fake bills, exhausted bills, etc. These operations are displayed on the display unit 500, and an alarm is issued from the alarm unit 600 when there is any abnormality. Further, instead of discharging, feeding and carrying may be stopped.

FIG. 3 is a block diagram showing the configuration of the main part of the security thread detection device related to the present invention. High frequency radio waves of about 300 kHz to 2000 kHz generated by the oscillation circuit 45 are amplified by the amplifier 46 and transmitted. Receiving antenna from wave antenna 50
It is issued to 60. The radio wave received by the receiving antenna 60 is tuned by the tuning circuit 210, and then the high frequency amplifier 220
The signal is taken out by the detection circuit 230 after high frequency amplification at
Low frequency amplification is performed by the low frequency amplification unit 240 and input to the chopper circuit 250. The chopper circuit 250 keeps the signal level constant as described later. Chopper circuit 250
Is output to the comparison circuit 260, where it is compared with a reference voltage serving as a reference to obtain a final detection output. The tuning circuit 210 to the comparison circuit 260 as described above constitute the security thread detection circuit 200.

FIG. 5 is a perspective view showing the structure of the transmitting antenna 50, and FIG. 6 is a sectional view thereof.

As is clear from these figures, this transmitting antenna is supported by embedding a metal antenna body 53 in a resin supporting member 52, and this supporting member 52 is provided in a shield case 51 having a U-shaped cross section. It is stored. The antenna main body 53 is connected to the oscillating section including the oscillating circuit 45 and the amplifying section 46 described above through the opening 54 provided in the shield case 51, and the other side of the oscillating section is connected to the shield case 51. Due to the presence of the shield case 51, the wave transmitting antenna 50 having such a configuration radiates electromagnetic waves only downward.

The transmitting antenna 50 and the receiving antenna are the ninth
As shown in the cross-sectional view of the figure, the mounting table 6 which forms the carrying surface of the carrying section.
It is desirable that the guide plate 14 be set back by a few mm, for example, about 4 mm from the surface of the guide plate 14. In order to form such a retreat in FIG. 9, the shield cases 51 and 61 are formed longer on the antenna body 53, 63 side than that shown in FIG. 6, respectively. By having such a retreat,
The positional relationship between the antenna and the paper sheet becomes substantially constant regardless of whether the paper sheet passes above or below the gap of the transport section having a gap of 3 to 5 mm, for example, and stable detection is possible.

In this embodiment, since rectangular holes are formed in the mounting table 6 and the guide plate 14 at the portions where the transmitting antenna 50 and the receiving antenna are attached, the ends of the bills are caught in these holes, It may cause a jam. In order to prevent this, in this embodiment, the holes are provided with grids or nets 55 and 65 that do not damage the radiation of radio waves.

FIG. 8 is a circuit diagram showing the configuration of the chopper circuit described above.

According to the figure, this chopper circuit mainly consists of two amplifiers.
251 and 252, and the output of the preceding low-frequency amplifier 241 having a feedback resistor R3 forming a low-frequency amplifier circuit has a first resistor 251 having a feedback resistor R2.
Is input to the second amplifying circuit 252 via a switch 253 and is composed of a resistor R1 and a capacitor C1.
And is input to the first amplifier 251. The switch 253 is an analog switch, and is turned on / off according to an instruction from the control unit as needed.

 Next, the operation of this chopper circuit will be described.

The switch 253 is turned on according to an instruction from the control unit when a sheet does not pass, and accumulates the output of the low frequency amplifier in the capacitor C1. Therefore, the output of the second amplifier 252 becomes an output according to the accumulated charge amount. Since this output is the comparison input of the first amplifier 251, the switch 253 is turned off when the paper sheet passes, and the output corresponding to the difference from the output of the low frequency amplifier 241 is the first output.
Output from the amplifier 251 of. In this way, the output is taken out with reference to the time when the paper sheet does not pass, so that the influence of environmental changes such as temperature can be eliminated.

FIG. 7 is an explanatory diagram showing the relationship between the banknote transport direction and the antenna direction. In general, the security thread is often included in a direction perpendicular to the longitudinal direction of the paper sheet, but the security thread detecting device of the present invention enables stable detection regardless of the direction of the security thread. That is, even if the antenna and the security thread are orthogonal to each other as shown in FIG. 7 (a),
Even if they are parallel as shown in FIG. 7 (b), they can be detected with similar detection accuracy. It is possible to detect in the same manner even when the paper sheet is slightly skewed.

Next, the operation of the security thread detecting device as described above will be described.

The security thread is generally about 0.7 mm wide and tens of
It is an elongated thin metal piece or resin piece having a thickness of μm. When paper sheets P having such a security thread, for example, banknotes are stored in the paper sheet storage unit 2 and the operation unit 400 is operated to start processing of the paper sheets,
The control device 100 drives the transport drive unit 800. That is, the bills are fed one by one by the rotation of the kicker roller 7, pass through the gap between the feed roller 9 and the gate roller 10,
It is transported by the transport rollers 11 and moved to the paper sheet collection unit 4. A pair of antennas 50 and 60 and counting elements 12 and 13 are provided in the conveyance path between the feed roller 9 and the conveyance roller 11.
Is provided, the security thread is detected in the former case and the number of sheets is detected in the latter case. A pair of antennas
When a bill passes between 50 and 60, security
When the thread is present, the radio wave emitted from the transmitting antenna by the security thread is reflected or absorbed by the security thread, so that the energy of the radio wave received by the receiving antenna is reduced. The radio wave thus received is tuned by the tuning circuit 210 in the security thread detection circuit 200, amplified by the high frequency amplification section 220, extracted by the detection circuit 230, and amplified by the low frequency amplification section 240. The level fluctuation is prevented by the chopper circuit 250, and the comparison circuit 2
The presence or absence of a security thread will be detected by the comparison with the reference voltage by 60.

FIG. 10 is a graph showing the output of the chopper circuit. It is observed that the banknote A having the security thread has a greater attenuation than the banknote B having no security thread. The security thread can be detected by comparing the voltage level thus obtained with the reference voltage level Vref in the comparison circuit 260 shown in FIG.
If the security thread is not confirmed for the banknotes on which the security thread should be,
The control unit 100 determines that there is an abnormality and causes the transport driving unit 800 to switch the transport path to eject the abnormal banknote from the excluding unit 700, or stop feeding and transporting. With respect to the occurrence of abnormal bills, the display unit 500 displays a message to that effect, and the alarm unit 600 issues an alarm with a buzzer, a lamp, or the like to alert the operator.

FIG. 11 shows an embodiment of the present invention, in which the antenna is divided.

According to this embodiment, the transmitting antenna is divided into two and is divided into two transmitting antennas 50a and 50b and a receiving antenna 60a.
It consists of 60b and each is operated separately.

That is, according to the first embodiment of the present invention, the transmitting antennas 50a and 50b are driven by the same high-frequency signal, while the receiving antenna 60a is the high-frequency radio wave transmitted from the antenna 50a. And the receiving antenna 60b receives the high frequency radio waves transmitted from the antenna 50b. And the receiving antenna 60 divided into two in this way
The detection results obtained by the radio waves received in a and 60b are compared with each other.

With such a configuration, it is possible to reliably detect the presence of the security thread, and it is possible to more reliably detect a banknote in which the position of the security thread is biased. Further, it becomes possible to detect the direction of the bill.

Further, according to the second embodiment of the present invention, a plurality of antennas having different characteristics are arranged in parallel. The transmitting antennas 50a and 50b are driven by different high frequency signals, while the receiving antenna 60a
The a receives the high frequency radio wave transmitted from the antenna 50a, and the receiving antenna 60b receives the high frequency radio wave transmitted from the antenna 50b. Then, the detection results obtained by the radio waves received by the two receiving antennas 60a and 60b are compared with each other.

In this case, since the reflection characteristic of the electric wave differs depending on the material of the security thread, it is possible to detect the security thread with high accuracy by generating the electric wave at the frequency most suitable for the material of the security thread.

Further, FIG. 12 shows another embodiment of the present invention. In this case, the number detecting sensors 12A, 12B, 12C and 12D are provided at four places around the receiving antenna 60. Although only the receiving side is shown in this figure, the transmitting side has a configuration corresponding to this, as described above. If the AND gate 301 does not obtain an ON output by taking the logical product of the outputs of these four sensors, it is determined that abnormal skewing has occurred, and the banknote is rejected regardless of whether the security thread is detected or not. An operation is performed to stop the transportation.

In the above embodiments, the processing device for handling banknotes was described, but the detection device of the present invention can be similarly applied to a device for handling other paper sheets such as checks.

〔The invention's effect〕

As described above, according to the security thread detecting device in the paper sheet processing apparatus according to the present invention, radio waves from the security thread are emitted to the conveyed paper sheet from the transmitting antenna and received by the receiving antenna. Security by observing attenuation due to reflection and absorption of
Since the thread is detected and various processing operations are performed based on the detection result, there is an effect that the authenticity determination and the processing associated therewith can be accurately performed.

In particular, according to the first embodiment, it is possible to reliably detect the presence of the security thread, and it is possible to more reliably detect a banknote in which the position of the security thread is biased. Since it is possible to provide a transmitting antenna and a receiving antenna according to the thread position of the banknote to be formed, it is possible to reliably confirm that the thread exists at a predetermined place, and it is also possible to detect the direction of the banknote. There is a remarkable effect.

Further, according to the second embodiment of the present invention, since the reflection characteristic of the radio wave differs depending on the material of the security thread, the radio wave is generated at a frequency or the like most suitable for the material of the security thread, thereby achieving high-precision security. -There is a unique effect that thread detection is possible.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the configuration of a paper sheet processing apparatus including an embodiment of a security thread detection apparatus related to the present invention, FIG. 2 is a block diagram showing the overall configuration, and FIG. 3 is security. Block diagram showing an embodiment of a configuration for detecting a sled, FIG. 4 is a perspective view showing an installation state of an antenna related to the present invention, FIG. 5 is a perspective view showing the configuration of the antenna, and FIG. Is a cross-sectional view thereof, FIG. 7 is an explanatory view showing the relationship between the conveyance direction of paper sheets and the direction of the antenna, FIG. 8 is a circuit diagram showing the configuration of a chopper circuit in the detection circuit, and FIG.
FIG. 10 is a cross-sectional view showing the relationship between the antenna and the transport path, FIG. 10 is a graph showing the security thread detection result, and FIG. 11 is a plan view showing the configuration of the security thread detection device in which the antenna according to the present invention is divided. FIG. 12 is a plan view showing an embodiment in which a plurality of sheet number detecting sensors are arranged around the antenna. 2 ... Paper storage unit, 3 ... Paper transport unit, 4 ... Paper collection unit, 9 ... Feed roller, 9A ... Transport guide roller, 10 ... Gate roller, 11 ... Transport Laura, 12 ……
Light-receiving element, 13 ... Light-emitting element, 50 ... Transmission antenna, 51 ...
… Shield case, 60… Receiving antenna, 100… Control unit, 200… Security thread detection circuit, 210…
Tuning circuit, 220 …… High frequency amplifier, 230 …… Detection circuit, 24
0 …… Low frequency amplifier, 250 …… Chopper circuit, 260 …… Comparison circuit, 300 …… Count sensor, 400 …… Operating section, 500 ……
Display unit, 600 ... Alarm unit, 700 ... Rejection unit, 800 ... Transport drive unit, 900 ... Counter unit.

Claims (9)

(57) [Claims] 1. A transporting unit that transports the paper sheet along a transport path to a processing unit that processes the input paper sheet, and sandwiches the transported paper sheet in the middle of the transport path. A plurality of pairs of transmitting and receiving antennas, which are provided to face each other and are operated separately, and drive the plurality of transmitting antennas with the same high-frequency signal, Transmitting and receiving means for separately receiving the high-frequency radio waves emitted by the plurality of receiving antennas facing each other, and comparing the detection signal detected by each of the receiving antennas with a predetermined reference voltage, each detection output A security thread detecting device for a paper sheet processing machine, comprising: a detecting means for detecting the presence of the security thread in the paper waves by determining 2. The security thread of a paper sheet processing machine according to claim 1, wherein the plurality of pairs of transmitting antennas and receiving antennas are arranged in the same row. Detection device. 3. The detector according to claim 1, further comprising a chopper circuit for outputting a reference signal for extracting a variation of the detection signal during a period in which the paper sheet is not conveyed. A security thread detection device for a paper sheet processing machine according to item 2. 4. The wave transmitting antenna or the wave receiving antenna is arranged so as to recede from a surface of a carrier path, according to any one of claims 1 to 3. Security thread detection device for paper processing machines. 5. A conveying unit that conveys the paper sheet along a conveyance path to a processing unit that processes the inserted paper sheet, and a conveyance unit that sandwiches the conveyed paper sheet in the middle of the conveyance path. A plurality of pairs of transmitting antennas and receiving antennas, which are provided so as to face each other and are separately operated, and a plurality of high-frequency signals having different characteristics based on the material of the security thread in the paper sheet are provided. Of the transmitting antennas, the transmitting and receiving means separately driving the transmitting antennas separately, and receiving the high-frequency radio waves emitted from the transmitting antennas by the receiving antennas, respectively, and detecting the receiving antennas. A detection unit for detecting the presence of the security thread in the paper sheet by comparing the detected signals with a predetermined reference voltage to obtain respective detection outputs; Security thread detector of the paper sheet handling machine, characterized in that it includes. 6. The security thread detecting device for a paper sheet processor according to claim 5, wherein the different characteristic based on the material of the security thread is a frequency characteristic. 7. The paper sheet processing machine according to claim 5, wherein the plurality of pairs of transmitting antennas and receiving antennas are arranged in the same row. Security thread detector. 8. The detection device according to claim 5, further comprising a chopper circuit for outputting a reference signal for extracting a variation of the detection signal in a period in which the paper sheet is not conveyed. Item 8. A security thread detecting device for a paper sheet processor according to any one of items 7. 9. The wave transmitting antenna or the wave receiving antenna is arranged so as to recede from a surface of a carrier path. Security thread detection device for paper processing machines.