JP2006293575A - Apparatus and method for identifying paper sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an apparatus for identifying paper sheets such as bills by means of a magnetic sensor to stably and accurately discriminate paper sheets by preventing adhesion of iron powder or iron sand, while being excellent in environment resistance. <P>SOLUTION: The apparatus includes a magnetic sensor 4 that, on the path of a print medium 1 having magnetic ink printed thereon, applies a magnetic field to the print medium 1, thereby magnetizing the print medium, and detecting a magnetic field produced by the residual magnetism of the magnetic ink magnetized at the rear of the path; and a medium approach detection means 5 for detecting based on signals from an approach sensor 3 the approach of the print medium 1 inserted from a slot 2. The magnetic sensor 4 has an electromagnet that, when the medium approach detection means 5 detects the approach of the print medium 1, produces a magnetic field for application to the print medium 1 in a direction perpendicular to the direction in which the print medium 1 is conveyed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a discriminating apparatus and discriminating method for paper sheets such as banknotes and thin plate-like media having a magnetic material.

  The magnetic field is applied to paper sheets with magnetic material such as banknotes and magnetic cards printed with magnetic ink, etc., and the residual magnetic field generated by the residual magnetism of the magnetic material is detected, and the detection result A method for identifying the authenticity of a paper sheet based on the above is known (see, for example, Patent Document 1). FIG. 22 is a perspective view showing the configuration of the magnetic sensor 100.

  This magnetic sensor 100 includes a magnet body 112 and a magnetism detection element 114 having two magnetism detection units 114a and 114b disposed via a magnetic shield member 113 in a holder 111. 112 includes a magnet 115 and a soft magnetic material 116 covering the magnet 115. The magnetic detection element 114 is accommodated in a nonmagnetic substrate 117, and a bias magnet 118 is disposed above the magnetic detection element 114. Reference numeral 119 denotes a terminal for taking out a detection signal.

  FIG. 23 is a diagram showing the positional relationship between the magnetized body 112 and the magnetic detection element 114. The relative positional relationship between the magnetic pole surface (hatched square portion) of the magnetic body 112 and the magnetic detection element 114 and the print medium 101 is shown. Show. FIG. 24 shows a magnetic field generated by the magnet 112.

  The magnetized body 112 applies a magnetizing magnetic field to the belt-shaped magnetized portion 101 a on the print medium 101 when the magnetic sensor 100 and the print medium 101 move relative to the relative movement direction Y. In other words, the magnetic ink applied in the magnetized portion 101a on the surface of the print medium 101 is magnetized prior to the detection. The magnetic detection element 114 detects the magnetic fields H1 and H2 due to the residual magnetism of the magnetic ink in the magnetized portion 101a due to the magnetization. At that time, it is necessary to prevent the strong magnetic field of the magnet 112 from affecting the weak magnetic field to be detected by the magnetic detection element 114.

  In this magnetic sensor 100, a quadrangular prism-shaped magnet 115 having a S-pole on the medium detection surface Sd side is provided perpendicular to the medium detection surface Sd, which is the lower end surface of the holder 111, and is U-shaped and has a quadrangular cross section. A soft magnetic body 116 such as permalloy or ferrite is combined so as to straddle the N pole opposite to the medium detection surface Sd of the magnet 115, and a magnetized body 112 having a generally E shape with the magnet 115 inside is provided. .

  The magnetic pole surfaces (three S poles of the magnet 115 and two N pole surfaces of the soft magnetic body 116), which are the three rectangular end faces on the open side of the E-shape of the magnet 112, are medium detection. The magnetized body 112 is arranged on the surface Sd so as to be in contact with or close to the surface of the print medium 101 in parallel and the three magnetic pole surfaces are aligned in a direction perpendicular to the relative movement direction Y.

  With this configuration of the magnetized body 112, the magnetic flux from the magnet 115 is concentrated in the direction connecting the magnetic pole surfaces as the end faces on the open side of the E-shape to each other (direction perpendicular to the relative movement direction Y). The magnetic field component extending to the element 114 can be extremely reduced, and the magnetic field components along the magnetic ink detection surface (surface) of the print medium 101 can be increased to increase the magnetic fields H1 and H2 from the magnetized portion 101a after magnetization. Can do.

  In this example, as shown in FIG. 24, the magnet 115 has an S pole and the soft magnetic body 116 has an N pole on the magnetic pole surface, and a magnetic field directed from the N pole to the S pole is applied to the print medium 101. Since the magnetic ink is magnetized, the magnetic ink side near the north pole of the magnet 112 is magnetized to the south pole, and the magnetic ink side near the south pole of the magnet 112 is magnetized to the north pole. As a result, the residual magnetism of the magnetized magnetic ink forms magnetic fields H1 and H2 in the directions of the arrows in the figure.

  Further, when it is necessary to further suppress the magnetic field propagation from the magnetized body 112 to the magnetism detecting element 114, as shown in FIG. 22, a magnetic shield member 113 such as a screen-shaped permalloy or amorphous is magnetically detected with the magnetized body 112. It arrange | positions between the elements 114. FIG.

  The magnetic detection element 114 made of a magneto-impedance element has two magnetic detection portions 114a and 114b formed in a zigzag pattern made of a high magnetic permeability magnetic thin film such as amorphous or permalloy on a nonmagnetic substrate 117 such as glass or ceramic. They are electrically connected in series. The zigzag linear pattern of the magnetism detection units 114a and 114b is the center of the magnetism detection element 114 as a connection point between the magnetism side magnetic pole surface which is the end surface on the medium detection surface side of the magnet 115 and the magnetism detection units 114a and 114b. The magnetic detectors 114a and 114b can have substantially the same characteristics so as to be symmetrical with respect to the straight line L connecting the two. Further, the magnet 115 and the magnetic detection element 114 are arranged so that the direction of the straight line L coincides with the relative movement direction Y, and the sensitivity of the magnetic detection units 114a and 114b with respect to the magnetic field of the magnetized portion 101a can be made substantially equal. ing.

  Then, the length in the longitudinal direction (direction perpendicular to the relative movement direction Y) of the zigzag folds of the magnetic detection units 114a and 114b is selected according to the required detection width of the detection target portion, and the number of zigzag folds according to the resolution. The width and spacing of the pattern lines are selected. The folded portions of the magnetic detection units 114a and 114b are held so as to be parallel to the medium detection surface Sd of the print medium 101 at intervals of a comma (.) Several millimeters order. The magnetic detection units 114a and 114b are arranged so that the longitudinal direction of each of the zigzag folding portions serving as the magnetic field detection direction faces the same direction and is orthogonal to the relative movement direction Y in a plane parallel to the surface of the print medium 101. It is configured to line up along the magnetic field detection direction.

  A biasing magnet 118 installed near the upper side of the magnetic detection element 114 generates a bias magnetic field Hb shown in FIG. 23, and sets the magnetic detection element 114 at a sensitive operating point. Thereby, the sensitivity of the magnetic detection units 114a and 114b with respect to the magnetic field of the magnetized unit 101a is made substantially equal. That is, in the state where the magnetic detection element 114 is biased by the bias magnetic field Hb and there is no other external magnetic field superimposed on the bias magnetic field Hb, the impedances of the magnetic detection units 114a and 114b are substantially equal and with respect to a minute external magnetic field. In this case, the impedance is linearly changed with substantially the same gradient. The detection signals of the magnetic detection units 114a and 114b are taken out from the side opposite to the medium detection surface Sd through the terminals 119 connected to both ends and the middle point of the serial connection of the magnetic detection units 114a and 114b.

  With such a configuration, when magnetic ink is detected, the magnetic sensor 100 is moved relative to the print medium 101 in the relative movement direction Y, and the print medium 101 is magnetized by the magnet 112 as described above. Then, a magnetic field generated according to the amount of magnetic ink in the magnetized portion is differentially detected by the magnetic detection units 114a and 114b of the magnetic detection element 114. At this time, since the magnetic fields H1 and H2 due to the residual magnetism of the magnetic ink are superimposed on the bias magnetic field Hb, the magnetic detection unit 114a receives the magnetic field (Hb−H1), and the magnetic detection unit 114b receives the magnetic field (Hb + H2).

  Therefore, when the impedance in a state where only the bias magnetic field Hb is present and no external magnetic field exists is used as a reference, the impedance of the magnetic detection unit 114a changes (decreases) in an amount proportional to (−H1), and the magnetic detection unit 114b. The impedance of the signal changes by an amount proportional to (+ H2) (in this case, increases). For this reason, when one end (for example, the magnetic detection unit 114a side) of the serial connection of the magnetic detection units 114a and 114b is grounded and a predetermined voltage is applied to the other end, an external magnetic field is present at the midpoint voltage of the serial connection. The voltage changes in proportion to the external magnetic field (H1 + H2) with respect to the reference voltage when not.

  Using this principle, in practice, for example, the voltage applied to the series connection is a high-frequency voltage, and the comparison voltage Vref indicating the baseline in the waveform of the detection output Vs of the voltage at the midpoint of the series connection is not present in the external magnetic field. Therefore, the comparison voltage Vref is extracted from the detection output Vs via the peak hold circuit and the minimum hold circuit, and the difference voltage between the comparison voltage Vref and the detection output Vs is extracted via the DC differential amplifier circuit. Thus, a magnetic field corresponding to the voltage proportional to the external magnetic field (H1 + H2), that is, the amount of magnetic ink printed on the printing medium 101 can be detected.

  In the configuration of the magnetic sensor 100 described above, the disturbance magnetic field affects both the magnetic detection units 114a and 114b in the form of a change in the bias magnetic field Hb, but the external magnetic field extracted from the midpoint of the serial connection of the magnetic detection units 114a and 114b. The voltage proportional to the magnetic field (H1 + H2) hardly changes, and the influence of a minute disturbance magnetic field is canceled.

  The above-described external magnetic field (H1 + H2) detection method is a so-called differential detection method in which the difference between the voltages at both ends of the magnetic detection units 114a and 114b is obtained in principle. As a method for performing such differential detection, for example, the midpoint of the series connection of the magnetic detection units 114a and 114b is grounded, and a high frequency current equal to each of the magnetic detection units 114a and 114b is supplied from both ends of the series connection, There is also a method in which the voltages generated in the magnetic detectors 114a and 114b at this time are detected, and the detected voltages are DC-differential amplified.

  In addition, a bill discriminating apparatus using a thin film fluxgate type magnetic sensor, which is a type of non-contact magnetic sensor, has been proposed (for example, see Patent Document 2). FIG. 25 is a block diagram showing an example of the configuration. This apparatus comprises a magnetic sensor control means 122 for controlling the magnetic sensor 121 and a determination means 123 for generating an output signal from the detection signal. The magnetic sensor control means 122 includes an oscillation means 122a, a frequency dividing means 122b, and an excitation. A drive unit 122c, an AC amplification unit 122d, a synchronous detection unit 122e, and an amplification unit 122f are provided.

  The magnetic sensor 121 has a configuration in which an excitation coil and a detection coil are wound around a closed magnetic circuit core, and the operation principle is that a high-frequency excitation magnetic field is applied to the closed magnetic circuit core by the excitation coil wound around the closed magnetic circuit core. The induction current caused by the excitation magnetic field is detected by the detection coil wound around the closed magnetic circuit core, and the change in the electromagnetic action in the closed magnetic circuit core due to the external magnetic field, that is, the change in the excitation state is detected by the detection coil. Is. Then, in cooperation with the magnetic sensor control unit 122, a detection signal that detects the influence of the action of the external magnetic field on the magnetic sensor 121 is given to the determination unit 123. The determination unit 123 includes a comparison determination unit 123a and a reference value signal generation unit 123b, and generates an output signal corresponding to the detection signal of the magnetic sensor 121.

It has also been proposed to identify the authenticity of a bill by discriminating the type of magnetic ink (see, for example, Patent Document 3). FIG. 26 is a cross-sectional view showing the configuration of the magnetic sensor.
This magnetic sensor uses two different ring heads. First, a sine wave is applied to the first differential ring head 131 from the drive coil 132 to generate an AC modulation magnetic field, which is output to the detection coil 133. The maximum magnetic flux density is detected from the peak of the AC modulated wave, and then the bill 102 is magnetized by the magnet 134 and the residual magnetization is detected from the detection coil 136 of the second ring head 135. Then, an output Bm from the detection coil 133 of the first differential ring head 131 and an output Br from the detection coil 136 of the second ring head 135 are input to a divider to obtain Bm / Br. Alternatively, the first differential ring head 131 may be a bias type ring head.

  In the above magnetic sensor, since the signal is not output from the second ring head 135 for the portion where the density of the magnetic ink is constant, it is necessary to obtain an integral value by an integrator, but the data processing is complicated. In addition, since an error due to integration is included, accurate residual magnetism cannot be detected directly. Further, even when identifying the type of magnetic ink and the magnetic pattern in combination, it is necessary to obtain an integral value for detecting the magnetic pattern, and similarly, it is not possible to detect the accurate residual magnetism directly.

  Furthermore, it is also known to use a semiconductor magnetoresistive element for the magnetic sensor (see, for example, Patent Document 1). FIG. 27 is a diagram showing the configuration of the identification device, which is a cross-sectional view of the semiconductor magnetoresistive element 141 viewed from the direction perpendicular to the relative movement direction indicated by the arrow with the print medium 101.

  The semiconductor magnetoresistive element 141 has two magnetic detectors 141a and 141b arranged in the front and rear in the direction of relative movement with the normal print medium 101, and these are differentially operated. This is because the single element of the magnetic detection units 141a and 141b has poor temperature characteristics and compensates for the temperature characteristics. In addition, a bias magnet 142 is installed on the back surface of the semiconductor magnetoresistive element 141, and the direction connecting the NS magnetic poles is perpendicular to the detection surface of the magnetic ink portion 101b of the print medium 101 (the surface of the print medium 101). ing. Such a semiconductor magnetoresistive element 141 has two magnetic detectors 141a and 141b before and after the traveling direction, so that the detection output has a differential waveform.

  However, in the method for detecting the edge of the magnetic ink portion 101b as described above, for example, the magnetic tape is attached to the print medium 101 to reproduce the edge information, or the image is counterfeited (replicated) with a copier using magnetic toner. ), The medium may pass the identification device. This is because only the differential pattern of the magnetic ink is captured, and the identification accuracy is insufficient.

  Therefore, in addition to the above pattern, by handling a signal corresponding to the amount of magnetic ink, it is possible to capture the strength of the magnetic ink, perform more advanced identification, and increase the identification accuracy.

  In addition, if only one of the two magnetic detectors is operated, the semiconductor magnetoresistive element can capture the strength according to the pattern and amount of the magnetic ink, but the poor temperature characteristics are exposed and the level is stable. It becomes difficult to ensure. Moreover, it is weak against a disturbance magnetic field, and S / N becomes worse.

Therefore, a magnetic sensor that can accurately detect a magnetic field according to the amount of magnetic ink is used, and in order to accurately detect a detection signal according to the amount of magnetic ink of the sensor, a magnetic impedance thin film magnetic sensor is installed. A method for measuring the residual magnetism of a magnetic ink by use is disclosed (for example, see Patent Document 4). A method of measuring the residual magnetism of magnetic ink using a fluxgate type magnetic sensor has also been proposed.
JP 2000-105847 A (FIGS. 4 and 10) Japanese Patent Laid-Open No. 11-7565 (FIG. 1) JP 59-120857 A Japanese Patent Laid-Open No. 2000-242824

  In the conventional paper sheet identification device as described above, the magnetizing magnet has a magnetic force of 1 K gauss or more, so in an actual environment, iron powder is sucked and a detection error occurs or adheres. Paper sheets may be damaged by iron powder. Furthermore, the magnetism has a problem that the magnetic quantity of the magnet varies greatly with temperature, changes with time, and the reliability of the detection output of the magnetic sensor is low. In order to compensate for this, when a ring head having a magnetic core capable of generating a strong magnetic field and an exciting coil is used, the groove width (gap) of the magnetized portion of the ring head is very narrow at 300 μm or less. Thus, it is impossible to perform magnetization so as to satisfy the length in the magnetic sensing direction, and accurate magnetic detection cannot be performed.

  In addition, when discriminating the type of magnetic ink, since the detection signal is not output from the ring head for the part where the density of the magnetic ink is constant, it is necessary to obtain the integral value with an integrator. There is a problem that data processing becomes complicated and an error due to integration is included, so that accurate residual magnetism cannot be detected directly. The same applies when detecting a magnetic pattern.

  The present invention has been made in view of the above points, and is a paper sheet that is excellent in environmental resistance, can prevent adhesion of iron powder, iron sand, and the like, and can identify the authenticity of paper sheets stably and accurately. It is an object of the present invention to provide an identification device and an identification method.

  In the present invention, in order to solve the above-mentioned problem, a magnetizing means for applying a magnetic field to the magnetic material on the transport path of a paper sheet having a magnetic material and magnetizing the magnetic material at a subsequent stage of the transport path. A magnetic detection means for detecting a magnetic field due to residual magnetism of the magnetic material; and a detection means for detecting the entry of the paper sheet. The magnetizing means is configured to detect when the detection means detects the entry of the paper sheet. There is further provided an apparatus for identifying a paper sheet, further comprising an electromagnet that generates a magnetic field to be applied to the magnetic body in a direction orthogonal to a conveyance direction of the paper sheet.

  According to such a paper sheet identification device, since the entrance of the paper sheet is detected and magnetized by an electromagnet, it is excellent in environmental resistance, can prevent adhesion of iron powder, iron sand, etc. stably. In addition, the authenticity of the paper sheet can be accurately identified.

  In order to solve the above-described problems, the present invention detects a magnetic flux density of the magnetized magnetic material by applying a magnetic field to the magnetic material on a conveyance path of paper sheets having the magnetic material. A bias type ring head, magnetic detection means for detecting a residual magnetic field of the magnetized magnetic body, detection signals of the bias type ring head and the magnetic detection means are compared with a reference signal stored in advance, and the detection is performed. Comparing and determining means for determining that the paper sheet is true when the signal is within an allowable range with respect to the reference signal is provided.

  According to such a paper sheet identification device, since it is magnetized by a bias-type ring head, it has excellent environmental resistance, can prevent adhesion of iron powder, sand iron, etc., and is stable and accurate. Can be identified.

  Further, in the present invention, in order to solve the above-described problem, a magnetizing means for applying a magnetic field to the magnetic material on the conveyance path of the paper sheet having the magnetic material and magnetizing the magnetic material at a subsequent stage of the conveyance path. The magnetic detection means for detecting the magnetic field due to the remanent magnetism of the magnetic material and the detection signal from the magnetic detection means are compared with a reference signal stored in advance, and the detection signal is within an allowable range with respect to the reference signal. There is provided a paper sheet identification device comprising: a comparison / determination unit that determines that the paper sheet is true in some cases.

  According to such a paper sheet identification apparatus, since a magnetic field is applied to the magnetic material and magnetized, it is excellent in environmental resistance, can prevent adhesion of iron powder, iron sand, etc., stably and accurately. Can identify the authenticity of leaves.

  The paper sheet identification apparatus and method of the present invention include an electromagnet that generates a magnetic field applied to a magnetic material of a paper sheet in a direction orthogonal to the paper sheet conveyance direction when the paper sheet is detected to enter. Since it is provided, there is an advantage that it is excellent in environmental resistance, can prevent adhesion of iron powder, iron sand and the like, and can identify the authenticity of paper sheets stably and accurately.

  The paper sheet identification apparatus and method of the present invention include a bias type ring head that magnetizes a magnetic material of a paper sheet by applying a magnetic field and detects the magnetic flux density of the magnetized magnetic material. Therefore, there is an advantage that it is excellent in environmental resistance, can prevent adhesion of iron powder, iron sand and the like, and can identify the authenticity of the paper sheet stably and accurately.

  In addition, the paper sheet identification device and identification method of the present invention are provided with a magnetizing means for applying a magnetic field to the magnetic material of the paper sheet, so that it has excellent environmental resistance, such as iron powder and iron sand. There is an advantage that adhesion can be prevented and the authenticity of the paper sheet can be identified stably and accurately.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a first embodiment of the present invention. Here, the configuration of a magnetic detection device for detecting a magnetic material of a paper sheet is shown.

  In the figure, reference numeral 1 denotes a printing medium inserted from the insertion slot 2, which holds a magnetic material that is magnetized by applying a magnetic field and generates a residual magnetic field, such as a check printed with banknotes or magnetic ink, on the surface or inside. It is a paper sheet or sheet-like paper sheet, and is relatively transported in the Y direction by transport means such as a transport roller or a transport belt (not shown).

  An entry sensor 3 for detecting the entry of the print medium 1 is provided on the upper surface side of the conveyed print medium 1. The ingress sensor 3 is an optical sensor that can detect the print medium 1 in a non-contact manner, such as a reflective photo interrupter, and is disposed on the front stage side with respect to the relative movement direction Y of the print medium 1. A magnetic sensor 4 as magnetic detection means is disposed on the upper surface side of the rear stage side.

  In addition, medium approach detecting means 5 for detecting the approach of the print medium 1 and energizing the magnetic sensor 4 is connected to the approach sensor 3. 6 is a magnetizing coil driving means for driving a magnetizing coil in the magnetic sensor 4 to be described later, 7 is a magnetism detecting element driving means for driving a magnetism detecting element in the magnetic sensor 4, and 8 is from the magnetic sensor 4. It is a magnetic detection circuit that detects the magnetism of the print medium 1 from the detection signal.

  FIG. 2 is a perspective view showing a configuration example of the magnetic sensor 4. The basic configuration of the magnetic sensor 10 shown in the figure is the same as that shown in FIG. 22, but is magnetized by applying a magnetic field to magnetic ink, which is a magnetic substance, in the holder 11 on the conveyance path of the print medium 1. The above-described magnetism detection that detects the magnetic field due to the residual magnetism of the magnetic ink that is partitioned by the electromagnet (magnetization means) 12 to be magnetized and the electromagnet 12 and the magnetic shield member 13 and magnetized in the subsequent stage of the transport path. An element (magnetic detection means) 14 is provided. The electromagnet 12 includes a soft magnetic body 15 that is a magnetic core and the above-described magnetizing coil (excitation coil) 16 wound around the soft magnetic body 15. A thin film fluxgate type magnetic detection element is used as the magnetic detection element 14. However, it may be a magnetic impedance element whose impedance changes according to an external magnetic field when a high frequency current is applied. The magnetic detection element 14 is provided on the nonmagnetic substrate 17 and is not provided with a biasing magnet. Reference numeral 18 denotes a coil terminal of the coil 16 connected to the magnetizing coil driving means 6 in FIG. 1, and 19 denotes a driving terminal of the magnetic detection element 14 connected to the magnetic detection element driving means 7.

  In the magnetizing electromagnet 12, a coil 16 is wound around a central leg portion among three quadrangular columnar legs of a soft magnetic body 15 having a quadrangular cross section and an E shape as a whole. The magnetic pole surfaces, which are the open end surfaces of the three quadrangular columnar legs, are arranged so as to be in contact with or close to the surface of the print medium 1 and aligned in a direction perpendicular to the relative movement direction Y. Yes.

  In the magnetic detection apparatus configured as described above, when the print medium 1 inserted from the insertion port 2 is transported by a transport means (not shown) and passes below the entrance sensor 3, the medium entrance detection means 5 is moved to the entrance sensor 3. , The arrival of the printing medium 1 is detected, and a detection signal indicating the arrival is transmitted to the magnetizing coil driving means 6 and the magnetic detection element driving means 7. Thereby, the magnetizing coil driving means 6 and the magnetic detection element driving means 7 energize the coil 16 and the magnetic detection element 14 via the coil terminal 18 and the drive terminal 19, and energize and drive the electromagnet 12 and the magnetic detection element 14. To do.

  Thereafter, the print medium 1 reaches the magnetic sensor 10 (corresponding to the magnetic sensor 4), and is first magnetized by the electromagnet 12 in the directions of the magnetization magnetic fields Hx and -Hx shown in FIG. When the print medium 1 is further conveyed and reaches the magnetic detection element 14, the magnetic detection element 14 is affected by the external magnetic fields H1 and H2 generated by the residual magnetism of the print medium 1 and superimposed on the bias magnetic field Hb. Then, similarly to the magnetic sensor 100 shown in FIG. 22, the magnetic detection circuit 8 is a sum of external magnetic fields H1 and H2 generated by the residual magnetism of the print medium 1 from the signal voltages obtained by the two magnetic detection units of the magnetic detection element 14. A value proportional to (H1 + H2) is differentially detected.

  In this way, the disturbance magnetic field is canceled, and the magnetic field corresponding to the amount of magnetic ink printed on the print medium 1 is accurately detected. In the present embodiment, the magnetic field for magnetization is generated only when the printing medium 1 is conveyed. Therefore, even if iron powder or the like adheres to the magnetic pole surface of the electromagnet 12 in an environment where iron powder or iron sand exists. The influence of can be eliminated. That is, even if iron powder or the like adheres, it can be removed when the printing medium 1 is not passing through, so that the magnetic pattern on the printing medium 1 can be detected stably with high reliability without damaging the printing medium 1. Can do.

  Therefore, it is excellent in environmental resistance, can prevent the adhesion of iron powder, iron sand, etc., and can identify the authenticity of paper sheets stably and accurately. Further, since the magnetizing electromagnet 12 is integrated in the holder 11 which is the same housing as the magnetic detection element 14, it is not easily affected by instrumental differences when attached to the magnetic detection device. Furthermore, a means for measuring the ambient temperature, such as a thermistor or a thermocouple, is additionally provided, and the current of the coil 16 of the electromagnet 12 is controlled by correcting the temperature, thereby stabilizing the magnetic field generated by the electromagnet 12 regardless of the temperature. It can also be converted.

  Further, the shape of the electromagnet 12 shown in FIG. 2 is not limited to this example, and may be configured as shown in FIG. 3, for example. The electromagnet 12 shown in the figure has a configuration in which magnetizing coils 16a and 16b are wound around two portions connecting three leg portions of an E-shaped soft magnetic body 15, respectively. In the case of this configuration, it is possible to control the amount of magnetization of the print medium 1 in the directions of the magnetization magnetic fields Hx and -Hx by the currents applied to the coils 16a and 16b, respectively, and to correct variations due to instrumental errors. And the magnetic pattern on the print medium 1 can be accurately detected.

FIG. 4 is a perspective view showing a second embodiment of the present invention, and shows another configuration example of the magnetic sensor 4 of FIG. The configuration of the entire magnetic detection device is the same as that shown in FIG.
The magnetic sensor 20 of the present embodiment includes two ring heads (magnetizing means) 22a and 22b that are magnetized in the holder 21 in the same direction as the conveyance direction of the print medium 1 and in the opposite direction, and a magnetic shield. Two magnetic detection elements (magnetic detection means) 24a and 24b are provided which are separated by the member 23 and detect respective magnetic fields due to the residual magnetism of the magnetic ink magnetized by the two ring heads 22a and 22b. It has been. Each of the ring heads 22a and 22b includes soft magnetic bodies 25a and 25b, which are magnetic cores, and magnetizing coils (excitation coils) 26a and 26b wound around the soft magnetic bodies 25a and 25b. A fluxgate type magnetic sensing element is used, but a magnetic impedance element whose impedance changes according to an external magnetic field when a high-frequency current is applied may be used. The magnetic detection elements 24a and 24b are provided on the nonmagnetic substrates 27a and 27b, and no biasing magnet is provided. 28 is a coil terminal of the coils 26a and 26b connected to the magnetizing coil driving means 6 in FIG. 1, and 29 is a driving terminal of the magnetic detection elements 24a and 24b connected to the magnetic detection element driving means 7.

  The magnetizing ring heads 22a and 22b have a configuration in which coils 26a and 26b are wound around soft magnetic bodies 25a and 25b each having a ring shape. The magnetic pole surfaces of the open-side grooves are in contact with or close to each other in the medium detection surface Sd with respect to the surface in the relative movement direction Y of the print medium 1 and are aligned in a direction perpendicular to the relative movement direction Y. Has been placed.

  FIG. 5 is a diagram showing operations of magnetization and magnetic detection by the magnetic sensor 20. Reference numerals 1 a and 1 b denote magnetized portions of the print medium 1. The ring heads 22a and 22b magnetize in a direction parallel to the conveyance direction of the print medium 1, one magnetization direction is the same as the conveyance direction of the print medium 1, and the other magnetization direction is the opposite direction. The magnetic detection elements 24a and 24b also detect a magnetic field in a direction parallel to the conveyance direction of the print medium 1, and one of the magnetic sensitive directions is the same as the conveyance direction of the print medium 1, and the other magnetic sensitive direction is the opposite direction. . FIG. 6 is a diagram showing a configuration example of the ring heads 22a and 22b, and shows the direction of the magnetic field by the coil 26 wound around the ring head 22. FIG.

  In the magnetic detection apparatus configured as described above, when the print medium 1 inserted from the insertion port 2 in FIG. 1 is transported by a transport means (not shown) and passes below the entrance sensor 3, the first implementation described above. As in the embodiment, the medium entry detection means 5 detects the arrival of the print medium 1 from the output signal of the entry sensor 3, and transmits a detection signal indicating the arrival to the magnetizing coil drive means 6 and the magnetic detection element drive means 7. . Thereby, the magnetizing coil driving means 6 and the magnetic detection element driving means 7 energize the coils 26a and 26b and the magnetic detection elements 24a and 24b through the coil terminal 28 and the driving terminal 29, and the ring heads 22a and 22b and the magnetic detection element. The detection elements 24a and 24b are energized and driven.

  Thereafter, the print medium 1 reaches the magnetic sensor 20 (corresponding to the magnetic sensor 4 in FIG. 1). First, the magnetizing ring heads 22a and 22b are used to magnetize the magnetic field Hx, Magnetized in the -Hx direction. At this time, the magnetizing ring head 22 magnetizes the print medium 1 in the vicinity of a very narrow groove (generally 300 μm or less), as shown in FIG.

  When the print medium 1 is further conveyed and reaches the magnetic detection elements 24a and 24b, the magnetic detection elements 24a and 24b are affected by the external magnetic fields H1 and H2 that are generated by the residual magnetism of the print medium 1 and are superimposed on the bias magnetic field Hb. . And the magnetic detection circuit 8 is the same as the magnetic sensor 100 shown in FIG. 22, and external magnetic fields H1 and H2 generated by the residual magnetism of the print medium 1 from the signal voltages obtained by the two magnetic detection units of the magnetic detection elements 24a and 24b. A value proportional to the sum of (H1 + H2) is differentially detected.

  In this way, the disturbance magnetic field is canceled, and the magnetic field corresponding to the amount of magnetic ink printed on the print medium 1 is accurately detected. In the present embodiment, the magnetic field for magnetization is generated only when the printing medium 1 is conveyed. Therefore, even if iron powder or the like adheres to the magnetic pole surface of the electromagnet 12 in an environment where iron powder or iron sand exists. The influence of can be eliminated. That is, even if iron powder or the like adheres, it can be removed when the printing medium 1 is not passing through, so that the magnetic pattern on the printing medium 1 can be detected stably with high reliability without damaging the printing medium 1. Can do.

  Therefore, it is excellent in environmental resistance, can prevent the adhesion of iron powder, iron sand, etc., and can identify the authenticity of paper sheets stably and accurately. In addition, since the magnetizing ring heads 22a and 22b are integrated in the holder 21 which is the same housing as the magnetic detection elements 24a and 24b, they are affected by instrumental differences when attached to the magnetic detection device. Hateful.

  FIG. 7 is a view showing a third embodiment of the present invention, and shows the operation of magnetization and magnetic detection by a magnetic sensor (corresponding to the magnetic sensor 4 in FIG. 1) 30 as in FIG. In the present embodiment, the two ring heads 32a and 32b for magnetization are arranged to be inclined with respect to a direction parallel to the relative movement direction Y of the bill 9 which is a paper sheet. Further, the magnetic sensing directions of the two magnetic detection elements 34 a and 34 b are also inclined with respect to the relative movement direction Y of the banknote 9. In other words, the ring heads 32a and 32b are magnetized in a direction in which the magnetization direction is a constant angle with respect to the conveyance direction of the bill 9 and parallel to each other by 180 degrees in opposite directions, and the conveyance of the bill 9 in the magnetization portions 9a and 9b. The component perpendicular to the direction is wider than the detection width of the magnetic detection elements 34a and 34b. Further, the magnetic detection elements 34a and 34b are also arranged so that the magnetic sensing directions are parallel to each other in the opposite direction of 180 degrees.

  In the example of FIG. 7, the grooves that generate the magnetic fields for magnetization of the two ring heads 32 a and 32 b are arranged so as to be parallel to each other, and are inclined with respect to the relative movement direction Y. At this time, the vertical component on the bill surface with respect to the relative movement direction Y of the groove portions of the ring heads 32 a and 32 b becomes the width of the magnetized portions 9 a and 9 b of the bill 9. And it arrange | positions so that the width | variety of this magnetized part 9a, 9b may become larger than the width | variety of the perpendicular direction on the banknote surface with respect to the relative moving direction Y of the magnetic detection elements 34a, 34b.

  In the magnetic detection device configured as described above, the bill 9 is first magnetized in the directions of the magnetization magnetic fields Hxy and -Hxy shown in FIG. 7 by the ring heads 32a and 32b. When the bill 9 is further conveyed and reaches the magnetic detection elements 34a and 34b, the magnetic detection elements 34a and 34b are generated by the residual magnetism of the bill 9, and are applied to the external magnetic fields H1 and H2 superimposed on the relative movement direction component of the bias magnetic field Hb. to be influenced.

  And the magnetic detection circuit 8 is the same as the magnetic sensor 100 shown in FIG. 22, and the external magnetic fields H1 and H2 generated by the residual magnetism of the bill 9 from the signal voltage obtained by the two magnetic detection units of the magnetic detection elements 34a and 34b. A value proportional to the sum (H1 + H2) is differentially detected. In this way, the disturbance magnetic field is canceled, and the magnetic field corresponding to the amount of magnetic ink printed on the banknote 9 is accurately detected.

FIG. 8 is a diagram showing a fourth embodiment of the present invention. Here, the configuration of a magnetic sensor (corresponding to the magnetic sensor 4 in FIG. 1) 40 is shown. (A) is side surface sectional drawing, (B) is a bottom view.
The magnetic sensor 40 applies a magnetic field to the magnetic ink printed on the banknote 9 on the conveyance path of the banknote 9 shown in FIG. 9 and magnetizes it, and detects the magnetic flux density of the magnetized magnetic ink. A ring head 41 and a magnetic impedance element 42 as magnetic detection means for detecting the residual magnetic field of the magnetized magnetic ink are provided. The ring head 41 has a bias drive coil 43 and a detection coil 44 for generating a magnetic field. A bias coil for applying a bias magnetic field is provided above the magnetic impedance element 42, and an external magnetic field together with the magnetic impedance element 42 is provided. It is surrounded by a magnetic shield member 46 for shielding from the change of the above. Then, the detection signals of the bias type ring head 41 and the magnetic impedance element 42 are compared with a reference signal stored in advance, and when the detection signal is within an allowable range with respect to the reference signal, the bill 9 is determined to be true. judge.

  9A and 9B are diagrams showing operations of magnetization and magnetic detection in the present embodiment, in which FIG. 9A is a side sectional view and FIG. 9B is a bottom view. The magnetization direction by the ring head 41 is the same as the gap direction of the ring head 41, and is the direction shown in the figure. On the other hand, the magnetic sensing direction of the magnetic impedance element 42 is not parallel to the magnetization direction.

  When detecting the magnetic ink material and magnetic pattern of the bill 9, the magnetic sensor 40 or the bill 9 is relatively moved in the direction of the arrow in FIG. 9, and the bill 9 is magnetized in a band shape by the ring head 41. Is detected by the detection coil 44, and the magnetic field of the magnetized portion 9a by the magnetic ink is detected by the magnetic impedance element 42. At this time, the sizes of the ring head 41 and the magnetic impedance element 42 are determined so that the width of the magnetized portion 9a magnetized by the ring head 41 is wider than the length of the magnetic impedance element 42 in the magnetic sensing direction. .

  The magnetic ink printed on the banknote 9 does not have a magnetic amount that is originally determined. For this reason, a magnetic field is applied in a direction corresponding to the detection of the magnetic ink to perform magnetization. Also, once magnetized magnetic ink is exposed to a strong magnetic field in the course of circulation of banknotes 9, the magnetization may be lost. For stable operation, magnetization can be performed immediately before detection of the magnetic ink. is necessary.

  FIG. 10 is a block diagram showing a configuration example of an identification device using the magnetic sensor 40 described above. When the insertion detection sensor 51 detects that the banknote 9 has been inserted, the control circuit 52 gives an operation start command to the drive circuit 53 and the signal processing unit 57 based on the detection signal. In accordance with this command, the drive circuit 53 causes a direct current to flow through the ring head 54 to start a magnetizing operation, and also causes a current to flow through the bias coil 56 to generate a bias magnetic field. Further, a magnetic sensor (into the magnetic sensor 40 in FIG. 8). Equivalent) 55 is driven. The output signal of the ring head 54 and the output signal of the magnetic sensor 55 are input to the signal processing unit 57, converted into signals, and sent to the comparison / determination means 58. The comparison / determination means 58 compares the input signal with the output signal of a genuine note that has been acquired and stored in advance, and performs authenticity determination. This determination result is output as a determination value. At that time, the type of magnetic ink can be determined from the formula Bm / Br, and the magnetic pattern can also be read from the output Br of the magnetic sensor 55.

FIGS. 11A and 11B show examples of magnetization curves of different types of magnetic ink. 12A and 12B show detection results (signal waveforms of the sensor) of the magnetic ink.
Outputs of part A and part B, which are different types of magnetic ink, are detected as differences in the outputs of the ring head 41 and the magnetic sensor 40, respectively. That is, the maximum magnetic flux density and the residual magnetic pattern according to the amount and type of magnetic ink printed on the banknote 9 can be accurately detected, and the type and magnetic amount of the magnetic ink can be detected from the result.

  FIG. 13 is a diagram showing an example of magnetization characteristics of magnetic ink and residual magnetization after saturation. In the initial state, the remanent magnetization shows some value between Br and -Br. Therefore, in order to obtain an output of residual magnetization according to the amount of magnetic ink, magnetization up to saturation magnetization is performed. In general, saturation can be achieved by applying a magnetization of about 1 kOe. Thus, by magnetizing the magnetic ink to the saturation state, it is possible to obtain residual magnetization according to the amount of the magnetic ink.

  FIG. 14 is a diagram showing a fifth embodiment of the present invention, and shows a configuration of a magnetic sensor 60 (corresponding to the magnetic sensor 40 of FIG. 8). (A) is side surface sectional drawing, (B) is a bottom view. In the present embodiment, a thin film fluxgate type magnetic detection element 62 is used as the magnetic detection means. Other configurations are the same as those shown in FIG. 8, but no biasing coil is provided. That is, the ring head 61 includes a bias drive coil 63 and a detection coil 64, and the thin film fluxgate type magnetic detection element 62 is surrounded by the magnetic shield member 65. The magnetization direction by the ring head 61 is the same as the gap direction of the ring head 61, and is the direction shown in the figure. On the other hand, the magnetic sensing direction of the thin film fluxgate magnetic detection element 62 is made not to be parallel to the magnetization direction.

  When detecting the magnetic ink material and magnetic pattern of the bill 9, the magnetic sensor 60 or the bill 9 is relatively moved in the direction of the arrow in FIG. 15, and the bill 9 is magnetized in a band shape by the ring head 61. Is detected by the detection coil 64, and the magnetic field of the magnetized portion 9a by the magnetic ink is detected by the thin film fluxgate type magnetic detection element 62. At this time, the ring head 61 and the thin film fluxgate magnetic sensing element 62 are arranged such that the width of the magnetized portion 9 a magnetized by the ring head 61 is wider than the length of the thin film fluxgate magnetic sensing element 62 in the magnetic sensing direction. The size of is determined.

  The magnetic ink printed on the banknote 9 does not have a magnetic amount that is originally determined. For this reason, a magnetic field is applied in a direction corresponding to the detection of the magnetic ink to perform magnetization. Also, once magnetized magnetic ink is exposed to a strong magnetic field in the course of circulation of banknotes 9, the magnetization may be lost. For stable operation, magnetization can be performed immediately before detection of the magnetic ink. is necessary.

  FIG. 16 is a block diagram showing a configuration example of an identification device using the magnetic sensor 60 described above. When the insertion detection sensor 71 detects that the banknote 9 has been inserted, the control circuit 72 gives an operation start command to the drive circuit 73 and the signal processing unit 76 based on the detection signal. In accordance with this command, the drive circuit 73 causes a direct current to flow through the ring head 74 to start the magnetization operation, and drives the magnetic sensor (corresponding to the magnetic sensor 60 in FIG. 14) 75. The output signal of the ring head 74 and the output signal of the magnetic sensor 75 are input to the signal processing unit 76, converted into signals, and sent to the comparison / determination means 77. The comparison / determination unit 77 compares the input signal with the output signal of a genuine note that has been acquired and stored in advance, and performs authenticity determination. This determination result is output as a determination value. At this time, the type of magnetic ink can be determined from the formula Bm / Br, and the magnetic pattern can also be read from the output Br of the magnetic sensor 75.

  The output results in the present embodiment are the same as those in the fourth embodiment described above, and the output results of different types of magnetic ink having the magnetization curves shown in FIGS. 11A and 11B are shown in FIG. As shown in (A) and (B). That is, the outputs of part A and part B, which are different types of magnetic ink, are detected as differences in the outputs of the ring head 61 and the magnetic sensor 60, respectively. That is, the maximum magnetic flux density and the residual magnetic pattern according to the amount and type of magnetic ink printed on the banknote 9 can be accurately detected, and the type and magnetic amount of the magnetic ink can be detected from the result.

  Next, a sixth embodiment of the present invention will be described. The configuration of the magnetic sensor of the present embodiment and the operations of magnetization and magnetic detection are the same as those of the fourth embodiment shown in FIGS. The angle between the magnetic direction and the magnetic sensitive direction of the magneto-impedance element 42 is not less than 0 degrees and less than 90 degrees. The dimension in the direction perpendicular to the banknote surface with respect to the conveyance direction of the banknote 9 in the width direction of the ring head 41 is the dimension in the direction perpendicular to the banknote surface with respect to the conveyance direction of the banknote 9 in the magnetic sensing direction of the magnetic impedance element 42. Greater than.

  FIG. 17 is a block diagram showing a configuration example of an identification device using the magnetic sensor of the present embodiment. As in the fourth embodiment, when the insertion detection sensor 81 detects that the bill 9 has been inserted, the control circuit 82 gives an operation start command to the drive circuit 83 and the signal processing unit 87 based on the detection signal. In accordance with this command, the drive circuit 83 causes a direct current to flow through the ring head 84 to start a magnetizing operation, and also causes a current to flow through the bias coil 85 to generate a bias magnetic field, and further to a magnetic sensor (to the magnetic sensor 40 in FIG. 8). Equivalent) 86 is driven. Then, the output signal of the ring head 84 and the output signal of the magnetic sensor 86 are input to the signal processing unit 87, converted into signals, and sent to the comparison / determination means 88. The comparison / determination means 88 compares the input signal with the output signal of a genuine note that has been acquired and stored in advance, and performs authenticity determination. This determination result is output as a determination value.

  FIG. 18 is a diagram showing the detection result of the magnetic ink in the present embodiment. The outputs of the A part and the B part having different magnetic ink densities are detected as the difference in the output of the magnetic sensor 86, respectively. That is, the magnetic field according to the amount of magnetic ink printed on the banknote 9 can be accurately detected.

  Next, a seventh embodiment of the present invention will be described. The configuration of the magnetic sensor of the present embodiment and the operations of magnetization and magnetic detection are the same as those of the fifth embodiment shown in FIGS. Is set to 1 kOe or more, and magnetization is performed to saturate the magnetic ink. Magnetization is performed by setting the output of the ring head 61 to be equal to or greater than the coercive force of the magnetic ink.

  FIG. 19 is a block diagram showing a configuration example of an identification device using the magnetic sensor of the present embodiment. Similar to the fifth embodiment, when the insertion detection sensor 91 detects that the banknote 9 has been inserted, the control circuit 92 gives an operation start command to the drive circuit 93 and the signal processing unit 96 based on the detection signal. In accordance with this command, the drive circuit 93 applies a direct current to the ring head 94 to start the magnetizing operation, and drives the magnetic sensor (corresponding to the magnetic sensor 60) 95. Then, the output signal of the ring head 94 and the output signal of the magnetic sensor 95 are input to the signal processing unit 96, converted into signals, and sent to the comparison / determination means 97. The comparison / determination means 97 compares the input signal with the output signal of a genuine note that has been acquired and stored in advance, and performs authenticity determination. This determination result is output as a determination value.

  FIG. 20 is a diagram showing an example of magnetization characteristics of magnetic ink. In the initial state, the remanent magnetization shows some value between Br and -Br. Therefore, in order to obtain an output of residual magnetization according to the amount of magnetic ink, magnetization up to saturation magnetization is performed. In general, saturation can be achieved by applying a magnetization of about 1 kOe. Thus, by magnetizing the magnetic ink to the saturation state, it is possible to obtain residual magnetization according to the amount of the magnetic ink.

  FIG. 21 is a diagram showing an example of magnetization characteristics of magnetic ink and residual magnetization after magnetization. By giving magnetization more than the coercive force of the magnetic ink, residual magnetization can be obtained even if the magnetization disappears in the initial state. In this case, output according to the amount of magnetic ink cannot be obtained due to the influence of the difference in the initial state, but the presence or absence of magnetic ink can be detected.

  As mentioned above, although each embodiment has been described, the present invention has the following identification process, is excellent in environmental resistance, can prevent adhesion to sensors such as iron powder and iron sand, and is scratched. Therefore, the authenticity of the paper sheet can be identified stably and accurately.

  (1) By a magnetizing process in which a magnetic field is applied to the magnetic material by an electromagnet on the conveyance path of the paper sheet having the magnetic material, and a residual magnetism of the magnetic material magnetized in the subsequent stage of the conveyance path A magnetic detection step for detecting a magnetic field; and a detection step for detecting the entry of the paper sheet. In the magnetization step, the magnetic material is applied when the entry of the paper sheet is detected in the detection step. A magnetic field to be generated is generated in a direction orthogonal to the transport direction of the paper sheet.

  (2) An application step of applying a magnetic field to the magnetic body by a bias type ring head on a conveyance path of a paper sheet having a magnetic body, a detection step of detecting a magnetic flux density of the magnetized magnetic body, and the magnetic A detection step for detecting a residual magnetic field of the body, and a detection signal in each detection step is compared with a reference signal stored in advance, and when the detection signal is within an allowable range with respect to the reference signal, the paper sheet And a comparison determination step for determining that the class is true.

  (3) A magnetization process in which a magnetic field is applied to the magnetic material on a conveyance path of a paper sheet having a magnetic material, and a magnetic field due to residual magnetism of the magnetic material magnetized in a subsequent stage of the conveyance path. The magnetic detection step to detect and the detection signal in the magnetic detection step are compared with a reference signal stored in advance, and the paper sheet is true when the detection signal is within an allowable range with respect to the reference signal. And a comparison determination step for determining that the object is present.

It is a block diagram which shows the 1st Embodiment of this invention. It is a perspective view which shows the structural example of the magnetic sensor of 1st Embodiment. It is a figure which shows the other shape of the electromagnet of FIG. It is a perspective view which shows the 2nd Embodiment of this invention. It is a figure which shows the operation | movement of the magnetization and magnetic detection in 2nd Embodiment. It is a figure which shows the structural example of the ring head of 2nd Embodiment. It is a figure which shows the 3rd Embodiment of this invention. It is a figure which shows the 4th Embodiment of this invention. It is a figure which shows the operation | movement of the magnetization and magnetic detection in 4th Embodiment. It is a block diagram which shows the structural example of the identification device using the magnetic sensor of 4th Embodiment. It is a figure which shows the example of the magnetization curve of different types of magnetic ink. It is a figure which shows the detection result of different types of magnetic ink. It is a figure which shows the example of the magnetization characteristic of magnetic ink, and the residual magnetization after saturation. It is a figure which shows the 5th Embodiment of this invention. It is a figure which shows the operation | movement of the magnetization and magnetic detection in 5th Embodiment. It is a block diagram which shows the structural example of the identification device using the magnetic sensor of 5th Embodiment. It is a block diagram which shows the structural example of the identification device using the magnetic sensor of the 6th Embodiment of this invention. It is a figure which shows the detection result of the magnetic ink in 6th Embodiment. It is a block diagram which shows the structural example of the identification device using the magnetic sensor of the 7th Embodiment of this invention. It is a figure which shows the example of the magnetization characteristic of magnetic ink. It is a figure which shows the example of the magnetization characteristic of magnetic ink, and the residual magnetization after magnetization. It is a perspective view which shows the structure of the conventional magnetic sensor. It is a figure which shows the arrangement | positioning relationship between the magnetic body of FIG. 22, and a magnetic detection element. It is a figure which shows the magnetizing magnetic field by the magnetized body of FIG.22 and FIG.23. It is a block diagram which shows the structural example of the identification apparatus of the conventional banknote. It is sectional drawing which shows the structure of the conventional magnetic sensor. It is sectional drawing which shows the structure of the identification device using the conventional semiconductor magnetoresistive element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Print medium 1a, 1b, 9a, 9b Magnetization part 2 Insertion port 3 Ingress sensor 4, 10, 20, 30, 40, 55, 60, 75, 86, 95 Magnetic sensor 5 Medium entrance detection means 6 Magnetization coil drive Means 7 Magnetic detection element driving means 8 Magnetic detection circuit 9 Banknote 11, 21 Holder 12 Electromagnet 13, 23, 46, 65 Magnetic shield member 14, 24a, 24b, 34a, 34b Magnetic detection element 15, 25a, 25b Soft magnetic body 16 , 16a, 16b, 26, 26a, 26b Coil 17, 27a, 27b Non-magnetic substrate 18, 28 Coil terminal 19, 29 Drive terminal 22, 22a, 22b, 32a, 32b, 41, 54, 61, 74, 84, 94 Ring head 42 Magneto-impedance element 43, 63 Bias drive coil 44, 64 Detection coil 51, 71, 81, 91 Insertion detection sensor 52, 72, 82, 92 Control circuit 53, 73, 83, 93 Drive circuit 56, 85 Bias coil 57, 76, 87, 96 Signal processing unit 58, 77, 88, 97 Comparison judgment means 62 Thin film flux Gate type magnetic sensor

Claims (20)

A magnetizing means for applying a magnetic field to the magnetic material on a conveying path of the paper sheet having the magnetic material;
A magnetic detection means for detecting a magnetic field due to residual magnetism of the magnetized magnetic material at a subsequent stage of the transport path;
Detecting means for detecting the entry of the paper sheet,
The magnetizing means includes an electromagnet that generates a magnetic field to be applied to the magnetic material when the detecting means detects the entry of a paper sheet in a direction perpendicular to the transport direction of the paper sheet. Paper sheet identification device.   2. The paper sheet identification apparatus according to claim 1, wherein the magnetic detection unit detects a magnetic field in a direction parallel to a transport direction of the paper sheet.   2. The paper sheet identification apparatus according to claim 1, wherein the electromagnet of the magnetizing means includes a magnetic core that generates the magnetic field and an excitation coil that excites the magnetic core.   2. The paper sheet identification apparatus according to claim 1, wherein the magnetizing means comprises a ring head having a magnetic core for generating the magnetic field and an exciting coil for exciting the magnetic core.   2. The paper sheet identification apparatus according to claim 1, wherein the magnetic detection means uses a thin film fluxgate type magnetic detection element.   2. The paper sheet identification apparatus according to claim 1, wherein the magnetic detection means uses a magnetic impedance element whose impedance changes in response to an external magnetic field when a high frequency current is applied.   2. The paper sheet identification apparatus according to claim 1, wherein the magnetic detection unit is operated by being energized when the detection unit detects the entry of the paper sheet. The magnetizing means comprises two ring heads that are magnetized in the same direction and the opposite direction to the transport direction of the paper sheet,
The magnetic detection means comprises two magnetic detection elements for detecting respective magnetic fields due to residual magnetism of the magnetic material magnetized by the two ring heads,
The magnetism is performed by the two ring heads with relative movement with respect to the paper sheet, and the magnetic field of the magnetized portion is differentially detected by the two magnetic detection elements. The paper sheet identification device according to 1. The magnetizing means has a magnetization direction having a certain angle with respect to the transport direction of the paper sheets, magnetizes in opposite directions to each other, and a perpendicular component to the transport direction of the paper sheets of the magnetized portion Consists of two ring heads wider than the detection width of the magnetic detection means,
The magnetic detection means comprises two magnetic detection elements for detecting respective magnetic fields due to residual magnetism of the magnetic material magnetized by the two ring heads,
The magnetism is performed by the two ring heads with relative movement with respect to the paper sheet, and the magnetic field of the magnetized portion is differentially detected by the two magnetic detection elements. The paper sheet identification device according to 1.   2. The paper sheet identification apparatus according to claim 1, wherein the magnetizing means and the magnetic detection means are integrated in the same casing. A bias-type ring head that detects a magnetic flux density of the magnetic material magnetized while applying a magnetic field to the magnetic material on a conveyance path of a paper sheet having a magnetic material;
Magnetic detection means for detecting a residual magnetic field of the magnetized magnetic material;
The detection signal of the bias type ring head and the magnetic detection means is compared with a reference signal stored in advance, and when the detection signal is within an allowable range with respect to the reference signal, the paper sheet is determined to be true. Comparing and determining means for determining;
An apparatus for discriminating paper sheets, comprising: A magnetizing means for applying a magnetic field to the magnetic material on a conveying path of the paper sheet having the magnetic material;
A magnetic detection means for detecting a magnetic field due to residual magnetism of the magnetized magnetic material at a subsequent stage of the transport path;
A comparison determination unit that compares a detection signal from the magnetic detection unit with a reference signal stored in advance and determines that the paper sheet is true when the detection signal is within an allowable range with respect to the reference signal. When,
An apparatus for discriminating paper sheets, comprising: The magnetizing means comprises a ring head having a magnetic core for generating the magnetic field and an exciting coil for exciting the magnetic core,
13. The paper sheet identification apparatus according to claim 12, wherein the magnetic detection means comprises a magnetic impedance element whose impedance changes according to an external magnetic field when a high frequency current is applied.   14. The paper sheet identification apparatus according to claim 13, wherein an angle between a magnetization direction of the ring head and a magnetic sensitivity direction of the magneto-impedance element is 0 degree or more and less than 90 degrees.   The dimension in the direction perpendicular to the sheet conveying direction of the sheet in the width direction of the ring head is in the sheet plane relative to the conveying direction of the sheet in the magnetosensitive direction of the magneto-impedance element. 14. The paper sheet discriminating apparatus according to claim 13, wherein the size is larger than the dimension in the right-angle direction.   14. The paper sheet identification apparatus according to claim 13, wherein magnetization is performed by setting the output of the ring head to 1 kOe or more to saturate the magnetic body.   14. The paper sheet identification apparatus according to claim 13, wherein magnetization is performed by setting an output of the ring head to be greater than a coercive force of the magnetic body. A magnetization step of applying a magnetic field to the magnetic material by an electromagnet on a conveyance path of a paper sheet having a magnetic material;
A magnetic detection step of detecting a magnetic field due to residual magnetism of the magnetized magnetic material at a subsequent stage of the transport path;
A detection step of detecting the entry of the paper sheet,
In the magnetizing step, a magnetic sheet to be applied to the magnetic material when the entry of the paper sheet is detected in the detecting step is generated in a direction orthogonal to a conveyance direction of the paper sheet. Identification method. An applying step of applying a magnetic field to the magnetic body by a bias type ring head on a transport path of a paper sheet having a magnetic body;
A detection step of detecting a magnetic flux density of the magnetized magnetic body;
A detection step of detecting a residual magnetic field of the magnetic material;
A comparison determination step of comparing the detection signal in each detection step with a reference signal stored in advance and determining that the paper sheet is true when the detection signal is within an allowable range with respect to the reference signal. When,
A method for identifying a paper sheet, comprising: A magnetization step of applying a magnetic field to the magnetic material on a conveyance path of the paper sheet having the magnetic material, and magnetizing the magnetic material;
A magnetic detection step of detecting a magnetic field due to residual magnetism of the magnetized magnetic material at a subsequent stage of the transport path;
A comparison determination step of comparing the detection signal in the magnetic detection step with a reference signal stored in advance, and determining that the paper sheet is true when the detection signal is within an allowable range with respect to the reference signal. When,
A method for identifying a paper sheet, comprising:

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