JP4771738B2 - Paper sheet identification device and magnetic sensor for paper sheet identification - Google Patents

Description

  The present invention relates to a paper sheet identification device and a magnetic sensor for paper sheet identification for identifying the authenticity and type of paper sheets such as banknotes and securities.

2. Description of the Related Art Conventionally, in an identification device such as a banknote, a method of detecting a pattern printed on a banknote with magnetic ink by an MR sensor (magnetic resistance sensor) and identifying the authenticity and type of the banknote has been adopted (for example, Patent Documents). 1).
JP 2003-35701 A

  However, along with the improvement of printing technology, there is a tendency for a bill to be identified as a genuine note only by detection by an MR sensor, so that a bill having a hologram pattern formed on a bill has come to be used. Since such a hologram pattern is formed of a nonmagnetic metal material such as aluminum, it cannot be detected by an MR sensor.

  Therefore, a method of mounting an optical sensor on the identification device is conceivable. However, when a magnetic sensor and an optical sensor are mounted on one identification device, the device configuration becomes complicated, and the device becomes larger. There is a problem that the cost increases.

  In view of the above problems, an object of the present invention is to detect a first pattern formed of a magnetic material and a second pattern formed of a nonmagnetic conductive material with a common sensor. An object of the present invention is to provide a paper sheet identification device and a paper sheet identification magnetic sensor.

  In order to solve the above-described problem, the present invention includes a magnetic sensor disposed in a conveyance path of paper sheets such as banknotes and checks, and is conveyed along the conveyance path based on a detection result of the magnetic sensor. In the paper sheet identification device for identifying a paper sheet, the magnetic sensor includes a core body having a magnetic sensing portion directed to the transport path, and the transport path is wound around the core body and supplied with an alternating current. An excitation coil for detecting a pattern for generating a magnetic field on the sheet, and based on a detection result of a change in magnetic field when the paper sheet is transported through the transport path, the paper sheet is formed of a magnetic material. The first pattern and the second pattern formed of a nonmagnetic conductive material on the paper sheet are detected.

  In the paper sheet identification apparatus according to the present invention, a magnetic body including a core body having a magnetic sensing portion and a pattern detection excitation coil wound around the core body and generating a magnetic field in the transport path is used. Therefore, the detection result of the magnetic field change when the paper sheet is conveyed on the conveyance path includes the magnetic field change caused by the first pattern formed of the magnetic material on the paper sheet. Therefore, the first pattern can be detected by the magnetic sensor. In addition, since the magnetic sensor used in the paper sheet identification apparatus according to the present invention generates a magnetic field in the transport path by the excitation coil for pattern detection, when the paper sheet is transported through the transport path, An eddy current is generated in the second pattern formed of the nonmagnetic conductive material. Therefore, the detection result of the magnetic field change when the paper sheet is conveyed on the conveyance path includes the magnetic field change caused by the second pattern in the paper sheet. Therefore, the second pattern can be detected by the magnetic sensor. Therefore, according to the present invention, since the first pattern formed of the magnetic material and the second pattern formed of the nonmagnetic conductive material can be detected by the common sensor, the apparatus configuration is simplified. Can be Therefore, it is possible to reduce the size and cost of the paper sheet identification apparatus.

  In the present invention, the second pattern is a hologram pattern formed of, for example, a nonmagnetic metal material.

  In the present invention, the magnetic sensor may be either self-excited or separately excited.

  In the present invention, in the magnetic sensor, the pattern detection excitation coil and the differential detection coil are wound around the core body, and the magnetic field change generated by the pattern detection excitation coil, It is preferable to detect the pattern based on the difference from the change in the magnetic field generated by the excitation coil for differential detection. That is, in the present invention, it is preferable to perform differential detection. With this configuration, paper sheets can be identified with high accuracy because they are not affected by environmental changes such as temperature.

  Further, in the present invention, for identifying a paper sheet for identifying a paper sheet on which a first pattern formed of a magnetic material and a second pattern formed of a nonmagnetic conductive material are formed. A magnetic sensor, comprising: a core body having a magnetic sensing part; and a pattern detection exciting coil wound around the core body and generating a magnetic field by supplying an alternating current.

  In the paper sheet identification device and the paper sheet identification magnetic sensor according to the present invention, a core body provided with a magnetic sensing part, and an excitation coil for pattern detection that is wound around the core body and generates a magnetic field in the conveyance path As a result of detecting the change in the magnetic field when the paper sheet is conveyed on the conveyance path, the magnetic field change caused by the first pattern formed of the magnetic material on the paper sheet is used. Is included. Therefore, the first pattern can be detected by the magnetic sensor. In addition, since the magnetic sensor used in the paper sheet identification apparatus according to the present invention generates a magnetic field in the transport path by the excitation coil for pattern detection, when the paper sheet is transported through the transport path, An eddy current is generated in the second pattern formed of the nonmagnetic conductive material. Therefore, the detection result of the magnetic field change when the paper sheet is conveyed on the conveyance path includes the magnetic field change caused by the second pattern in the paper sheet. Therefore, the second pattern can be detected by the magnetic sensor. Therefore, according to the present invention, since the first pattern formed of the magnetic material and the second pattern formed of the nonmagnetic conductive material can be detected by the common sensor, the apparatus configuration is simplified. Can be Therefore, it is possible to reduce the size and cost of the paper sheet identification apparatus.

  Hereinafter, a magnetic sensor to which the present invention is applied and a paper sheet identification apparatus using the magnetic sensor will be described with reference to the drawings.

(overall structure)
FIG. 1 is a configuration diagram showing a main configuration of a paper sheet identification device to which the present invention is applied. In FIG. 1, a paper sheet identification device 1 according to the present embodiment is a device for detecting a pattern formed on a paper surface of a paper sheet 2 such as a banknote or a check, and identifying its authenticity and type. By detecting the first pattern 21 formed on the leaf 2 with a magnetic material such as magnetic ink and the second pattern 22 formed on the paper leaf 2 with a nonmagnetic conductive material such as aluminum, paper is detected. Identify the authenticity and type of leaf 2. Here, the second pattern 22 is formed as a hologram pattern or the like.

  The paper sheet identification device 1 according to the present embodiment includes a transport mechanism (not shown) that transports the paper sheet 2 along the transport path 3 while keeping the paper sheet 2 face down, and a magnetic sensor 10 that is disposed in the middle of the transport path 3. A power supply circuit (not shown) for supplying an alternating current to the magnetic sensor 10 and a detection circuit (not shown) for processing the output from the magnetic sensor 10 are provided. Here, a plurality of magnetic sensors 10 are arranged in the width direction of the conveyance path 3 (the direction intersecting the conveyance direction of the paper sheet 2), and a portion of the sheet 2 that is conveyed and passes through the lower position thereof is arranged. Detect patterns in time series. Note that the conveyance direction of the paper sheet 2 is indicated by an arrow W.

(Configuration of magnetic sensor)
2A and 2B are a principle diagram of a self-excited magnetic sensor that can be used in a paper sheet identification apparatus to which the present invention is applied, and a principle diagram of a separately excited magnetic sensor. 3 (a), (b), (c), and FIG. 4 are explanatory diagrams of a self-excited magnetic sensor that can be used in a paper sheet identification device to which the present invention is applied, and a case where differential detection is employed. It is explanatory drawing.

  In the paper sheet identification apparatus 1 to which the present invention is applied, as the magnetic sensor 10, both the self-excited magnetic sensor 10 shown in FIG. 2A and the separately excited magnetic sensor 10 shown in FIG. Can be used. A self-excited magnetic sensor 10 shown in FIG. 2A includes a core body 11 having a magnetic sensing part 110 directed toward the transport path 3 and a magnetic field generated in the transport path 3 by being wound around the core body 11. An excitation coil 12 for pattern detection and a resistor 13 electrically connected to both ends of the excitation coil 12 are provided. The voltage Vout at both ends of the resistor 13 is output to the detection circuit, and this output can detect a magnetic field change when the paper sheet 2 is transported through the transport path 3. Here, the core body 11 is made of ferrite, permalloy, amorphous magnetic material, or the like.

  A separately-excited magnetic sensor 10 shown in FIG. 2B includes a core body 11 having a magnetic sensing part 110 directed toward the conveyance path 3 and generates a magnetic field in the conveyance path 3 by being wound around the core body 11. An excitation coil 12 for pattern detection and a detection coil 14 wound around the core body 11 are provided. The voltage Vout at both ends of the detection coil 14 is output to the detection circuit, and the change in the magnetic field when the paper sheet 2 is transported through the transport path 3 can be detected by this output. Here, the core body 11 is made of ferrite, permalloy, amorphous magnetic material, or the like.

  Among such magnetic sensors 10, as a self-excited magnetic sensor 10, for example, as shown in FIG. 3A, one vertical plate 112 from the center of the horizontal plate 111 toward the conveyance path 3. In this case, the excitation coil 12 for pattern detection is wound around the vertical plate portion 112, and the end portion of the vertical plate portion 112 is used as the magnetic sensing portion 110. .

  Further, as the self-excited magnetic sensor 10, as shown in FIG. 3B, three vertical plates from the center of the horizontal plate portion 111, one end portion, and the other end portion toward the conveyance path 3. E-shaped ones with the portions 112, 113, 114 extending can be used. In this case, the excitation coil 12 for pattern detection is wound around the central vertical plate portion 112, and the end of the vertical plate portion 112 is Used as the magnetic sensing unit 110.

  Further, when the differential detection method is adopted for signal detection, as the self-excited magnetic sensor 10, for example, as shown in FIG. 3C, the center of the horizontal plate portion 111, one end portion, and From the other end, a total of six vertical plate portions 112, 113, 114, 115, 116, 117 extending toward the conveyance path 3 and the opposite side can be used. In this case, the excitation coil 12 for pattern detection is wound around the central vertical plate 112 extending toward the conveyance path 3, and the end of the vertical plate 112 is used as the magnetic sensing unit 110. Further, a differential detection coil 15 is wound around a central vertical plate 115 extending toward the side opposite to the conveyance path 3. Here, the excitation coil 12 for pattern detection and the coil 15 for differential detection are connected in series, supplied to an alternating current at both ends thereof, and the excitation coil 12 for pattern detection and the differential detection coil 15 are supplied. A signal is output from the connection point with the coil 15.

  When signal detection is performed using such a magnetic sensor 10 by the differential detection method, the drive circuit shown in FIG. 4 is used. The drive circuit includes a common power supply circuit 40 that supplies an alternating current to the excitation coil 12 for pattern detection of each of the plurality of magnetic sensors 10, and the coil 15 for differential detection, and a plurality corresponding to each magnetic sensor 10. Sensor signal processing circuit 30. The sensor signal processing circuit 30 includes a differential amplifier 31, a rectifier circuit 32 such as a half-wave rectifier circuit or a full-wave rectifier circuit, a low-pass filter 33, an amplifier amplifier 34, and the like, and outputs an output signal from each magnetic sensor 10. Amplify. Further, the authenticity and type of the paper sheet 2 are identified by collating output patterns output from the sensor signal processing circuits 30.

(Operation)
FIGS. 5A and 5B are explanatory views showing an example of paper sheets placed on the paper sheet identification device of the present embodiment, and explanatory views showing sensor outputs when the paper sheets are placed.

  In the paper sheet identification apparatus 1 of the present embodiment, as shown in FIG. 5A, a first pattern 21 made of magnetic ink and a second pattern 22 made of a hologram pattern are formed on the paper surface. When the paper sheet 2 is set, the output shown in FIG. 5B is obtained from the magnetic sensor 10 that measures the position indicated by the arrow L in FIG.

  In the output shown in FIG. 5B, first, in the period t <b> 1 in which the region L <b> 1 where the first pattern 21 is formed on the paper sheet 2 passes below the magnetic sensor 10, the first pattern 21 has a magnetic permeability. Since it rises, the output becomes high level. Next, in the period t2 in which the region L2 between the region L1 where the first pattern 21 is formed and the region L3 where the second pattern 22 is formed in the paper sheet 2 passes below the magnetic sensor 10, Since neither the first pattern 21 nor the second pattern 22 is formed in the region L2, the output becomes an intermediate level. In a period t3 in which the region L3 where the second pattern 22 is formed on the paper sheet 2 passes below the magnetic sensor 10, an eddy current is generated in the second pattern 22, and thus the output is at a low level. Then, after the region L3 in which the second pattern 22 is formed on the paper sheet 2 passes under the magnetic sensor 10, the region L4 includes the first region L4 in the period t4 when the region L4 passes below the magnetic sensor 10. Since neither the pattern 21 nor the second pattern 22 is formed, the output becomes an intermediate level.

(Main effects of this form)
As described above, in the paper sheet identification device 1 according to the present embodiment, the core body 11 including the magnetic sensing unit 110 and the excitation for pattern detection that is wound around the core body 11 and generates a magnetic field in the transport path 3. Since the magnetic sensor 10 including the coil 12 is used, the detection result of the magnetic field change when the paper sheet 2 is transported through the transport path 3 includes a first pattern 21 formed of a magnetic material on the paper sheet 2. The magnetic field change resulting from is included. Therefore, the first pattern 21 can be detected by the magnetic sensor 10. Further, since the magnetic sensor 10 used in the paper sheet identification device 1 according to the present embodiment generates a magnetic field in the transport path 3 by the excitation coil 12 for pattern detection, the paper sheet 2 is transported through the transport path 3. An eddy current is generated in the second pattern 22 formed of the nonmagnetic conductive material on the paper sheet 2. Accordingly, the detection result of the magnetic field change when the paper sheet 2 is transported through the transport path 3 includes the magnetic field change caused by the second pattern 22 in the paper sheet 2. Therefore, the second pattern 22 can also be detected by the magnetic sensor 10. Therefore, according to this embodiment, the common magnetic sensor 10 can detect the first pattern 21 formed of a magnetic material and the second pattern 22 formed of a nonmagnetic conductive material. The device configuration can be simplified. Therefore, the paper sheet identification device 1 can be reduced in size and cost.

  In addition, since the differential detection method is employed in detecting the signal, the influence of environmental changes such as temperature can be offset, so that the paper sheet 2 can be identified with high accuracy.

It is a block diagram which shows the principal part structure of the paper sheet identification device to which this invention is applied. (A), (b) is the principle figure of the self-excitation type magnetic sensor which can be used for the paper sheet identification device to which this invention is applied, and the principle figure of another excitation type magnetic sensor. (A), (b), (c) is explanatory drawing of the self-excitation type magnetic sensor which can be used for the paper sheet identification device to which this invention is applied. It is explanatory drawing at the time of employ | adopting differential detection in the paper sheet identification device to which this invention is applied. (A), (b) is explanatory drawing which shows an example of the paper sheets set to the paper sheet identification device to which this invention is applied, and explanatory drawing which shows the sensor output when this paper sheet is set.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper sheet identification apparatus 2 Paper sheet 3 Conveyance path 10 Magnetic sensor (Magnetic sensor for paper sheet identification)
11 Core body 12 Excitation coil 15 for pattern detection Coil 110 for differential detection Magnetosensitive part

Claims (5)

In a paper sheet identification device that includes a magnetic sensor disposed in a paper sheet conveyance path and identifies the paper sheet conveyed through the conveyance path based on a detection result of the magnetic sensor,
The magnetic sensor includes a core body having a magnetic sensing portion directed to the transport path, and an excitation coil for pattern detection that is wound around the core body and generates a magnetic field in the transport path by supplying an alternating current. Prepared,
Based on a detection result of a magnetic field change when the paper sheet is transported through the transport path, a first pattern formed of a magnetic material on the paper sheet and a nonmagnetic conductive property on the paper sheet A paper sheet identification device that detects a second pattern formed of a material.   2. The paper sheet identification apparatus according to claim 1, wherein the second pattern is a hologram pattern formed of a nonmagnetic metal material.   3. The paper sheet identification apparatus according to claim 1, wherein the magnetic sensor is self-excited or separately excited. The magnetic sensor according to any one of claims 1 to 3, wherein the excitation coil for pattern detection and a coil for differential detection are wound around the core body.
The paper sheet is characterized in that the pattern is detected based on a difference between a change in the magnetic field generated by the excitation coil for pattern detection and a change in the magnetic field generated by the excitation coil for differential detection. Identification device. A paper sheet identification magnetic sensor for identifying a paper sheet on which a first pattern formed of a magnetic material and a second pattern formed of a nonmagnetic conductive material are formed,
A paper sheet identification magnetic sensor comprising: a core body having a magnetic sensing section; and a pattern detection excitation coil wound around the core body to generate a magnetic field by supplying an alternating current. .

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