JP5889697B2 - Paper sheet magnetism evaluation apparatus and paper sheet magnetism evaluation method - Google Patents

Description

  The present invention relates to a paper sheet magnetism evaluation apparatus and a paper sheet magnetism evaluation method for evaluating the magnetic properties of a paper sheet, and in particular, from a paper sheet containing both a soft magnetic material and a hard magnetic material to each magnetic material. The present invention relates to a paper sheet magnetic property evaluation apparatus and a paper sheet magnetic property evaluation method for performing magnetic evaluation of the paper sheet by detecting the magnetic field.

  Conventionally, a paper sheet magnetic property evaluation apparatus for detecting a magnetic material in various fields has been used. For example, a paper sheet magnetic evaluation apparatus is used to identify the authenticity and type of paper sheets. Some paper sheets are printed using magnetic ink so that the authenticity and type can be identified, and some include a magnetic thread. Such a magnetic property of the paper sheet can be evaluated by a paper sheet magnetic evaluation apparatus, and the obtained evaluation result can be used for the paper sheet identification process.

  For example, Patent Document 1 discloses an apparatus in which a plurality of detectors are arranged in a line of two rows and the magnetic characteristics of the entire surface of a paper sheet transported in a short length are measured by the detectors of each line. Yes. A paper sheet to be measured has a magnetic ink region printed with a magnetic ink that is a soft magnetic material, and a magnetic thread made of a hard magnetic material is included in the magnetic ink region. In this apparatus, the magnetic thread existing in the magnetic ink region can be detected by utilizing the difference in coercive force between the soft magnetic material and the hard magnetic material.

Japanese National Patent Publication No. 11-511883

  However, according to the above prior art, since a large number of detectors are used to detect the soft magnetic material and the hard magnetic material, there is a problem that the size of the entire apparatus increases and the manufacturing cost increases.

  For example, when eight magnetic detection elements are used as a detector, 16 elements in two columns and a signal processing circuit for 16 channels for processing a signal from each element are required. If these elements and components are arranged to configure the apparatus, the entire apparatus becomes large and the manufacturing cost increases. In order to scan the entire paper sheet in a shorter time and process it at high speed, a method of transporting banknotes in a direction parallel to the short side is effective. As the number of elements and signal processing circuit components required increases, this problem becomes more prominent.

  The present invention has been made in order to solve the above-described problems caused by the conventional technology. While suppressing the manufacturing cost, the present invention can be applied to various magnetic materials from paper sheets including both soft magnetic materials and hard magnetic materials. An object of the present invention is to provide a paper sheet magnetic property evaluation apparatus and a paper sheet magnetic property evaluation method for performing magnetic evaluation of the paper sheet by detecting its presence.

In order to solve the above-described problems and achieve the object, the present invention is a paper sheet magnetic property evaluation apparatus, which generates a bias magnetic field in a region of the transport path in a transport path in which the paper sheet is transported. A first detection region for magnetizing both the soft magnetic material and the hard magnetic material contained in the paper sheet, and the hard magnetic material or the soft magnetic material depending on the intensity of a bias magnetic field in a region different from the first detection region And a second detection region that can detect any one of the first and second in a distinguishable manner, and further, a plurality of magnetic detection elements arranged in a line in the first detection region are arranged to scan the paper sheets. A first magnetic sensor that detects both the soft magnetic body and the hard magnetic body included in the paper sheet; and the magnetic detection element that forms the first magnetic sensor in the second detection region. arranged number of magnetic detection elements less than the number, the It scans the sheets, characterized by comprising a second magnetic sensor for detecting only one of the soft magnetic body or the hard magnetic included in the paper sheet at a lower resolution than the first magnetic sensor And

  Further, the present invention is the above-described invention, wherein the bias magnetic field is a first bias magnetic field magnet for magnetizing both the soft magnetic material and the hard magnetic material included in the paper sheet in the first detection region. A bias magnetic field magnet unit for detecting only the hard magnetic material with the second detection region provided on the downstream side of the first detection region and setting the magnetization intensity of the soft magnetic material to 0 (zero). The second magnetic sensor detects only the hard magnetic material contained in the paper sheet without using the magnetic field.

  Further, the present invention is the above invention, further comprising a magnetizing magnet unit for saturation magnetization of the paper sheets upstream of the transport path with respect to the first detection area and the second detection area. And

  Further, the present invention is the above-described invention, wherein the bias magnetic field is a first bias magnetic field magnet for magnetizing both the soft magnetic material and the hard magnetic material included in the paper sheet in the first detection region. The second detection region is provided on the downstream side of the first detection region, and a second bias magnetic field is used to detect only the soft magnetic material by setting the magnetization intensity of the hard magnetic material to 0 (zero). A magnet unit is used, wherein the second magnetic sensor detects only the soft magnetic material contained in the paper sheet.

  Further, the present invention is the above-described invention, wherein the bias magnetic field is a first bias magnetic field magnet for magnetizing both the soft magnetic material and the hard magnetic material included in the paper sheet in the first detection region. A bias magnetic field magnet unit for detecting only the hard magnetic material with the second detection region provided upstream of the first detection region and setting the magnetization intensity of the soft magnetic material to 0 (zero). The second magnetic sensor detects only the hard magnetic material contained in the paper sheet.

  Further, the present invention is the above-described invention, wherein the bias magnetic field is a first bias magnetic field magnet for magnetizing both the soft magnetic material and the hard magnetic material included in the paper sheet in the first detection region. The second detection region is provided upstream of the first detection region, and a second bias magnetic field is used to detect only the soft magnetic material by setting the magnetization intensity of the hard magnetic material to 0 (zero). A magnet unit is used, wherein the second magnetic sensor detects only the soft magnetic material contained in the paper sheet.

  In the present invention, the second magnetic sensor provided in the second detection region is configured by one magnetic detection element.

  Further, the present invention is the above invention, wherein the second magnetic sensor provided in the second detection area has a detection area shorter than the first magnetic sensor, and the soft magnetic material or It arrange | positions in the position corresponding to the magnetic body made into a detection object among the said hard magnetic bodies, It is characterized by the above-mentioned.

  In the invention described above, the second magnetic sensor provided in the second detection area is configured by a plurality of magnetic sensors having a detection area shorter than the first magnetic sensor. .

The present invention also relates to a method for evaluating the magnetic properties of a paper sheet, wherein a bias magnetic field is generated in a transport path through which the paper sheet is transported to magnetize both the soft magnetic material and the hard magnetic material included in the paper sheet. A first magnetic detection step of scanning the magnetized paper sheet and detecting both a soft magnetic material and a hard magnetic material contained in the paper sheet by a first magnetic sensor; and the bias magnetic field A second magnetic detection step in which the paper sheet is scanned in a region free of light and a second magnetic sensor having a resolution lower than that of the first magnetic sensor detects only the hard magnetic material included in the paper sheet. It is characterized by that.

The present invention is also a paper sheet magnetic property evaluation method, wherein a bias magnetic field is generated in a transport path through which a paper sheet is transported to saturate both a soft magnetic material and a hard magnetic material contained in the paper sheet. A magnetizing step for magnetizing and generating a bias magnetic field in a transport path through which the paper sheet is transported to magnetize both the soft magnetic material and the hard magnetic material contained in the paper sheet, and the magnetized paper sheet A first magnetic detection step of scanning and detecting both a soft magnetic material and a hard magnetic material included in the paper sheet by a first magnetic sensor; and generating a bias magnetic field of a predetermined strength to generate the paper sheet The soft magnetic material contained in the paper sheet is scanned by the second magnetic sensor having a resolution lower than that of the first magnetic sensor by magnetizing only the soft magnetic material contained in the magnetic material and scanning the magnetized paper sheet. And a second magnetic detection step for detecting only The features.

Further, according to the present invention, in the above invention, the magnetic substance detection result of the soft magnetic body and the hard magnetic body obtained by the first magnetic sensor, and the soft magnetic body or the hard magnetic body obtained by the second magnetic sensor. on the basis of the magnetic body detection result of the body, further comprising, said second magnetic sensor detection result calculation step of calculating a detection result of the second said to be detected outside of the magnetic sensor hard magnetic or the soft magnetic material When the paper sheets distributed in a state where the distribution areas of the two types of magnetic bodies do not overlap in the unit detection area of the target detection area, the detection result calculation step includes the detection target of the second magnetic sensor. By comparing the detection result of the hard magnetic body and the soft magnetic body of the first magnetic sensor in the area with the detection result of the magnetic body to be detected by the second magnetic sensor, the first magnetic sensor A detection result indicating the distribution of the hard magnetic detection results of the capacitors, and separating the detection result indicating the distribution of the soft magnetic material.

  According to the present invention, both the soft magnetic material and the hard magnetic material included in the paper sheet are detected by the first magnetic sensor, and only one of the soft magnetic material and the hard magnetic material is detected by the second magnetic sensor. By doing so, each detection result of the soft magnetic material and the hard magnetic material can be obtained. Moreover, it can be set as a low-cost apparatus by reducing the number of the magnetic detection elements which form a 2nd magnetic sensor.

  Further, according to the present invention, the number of the magnetic detection elements forming the second magnetic sensor can be reduced to one, so that a lower cost apparatus can be obtained.

  Further, according to the present invention, the second magnetic sensor is disposed only at the position where the magnetic material passes, so that the overall length of the second magnetic sensor can be shortened, and a low-cost and space-saving device can be obtained.

  According to the present invention, the soft magnetic material detected by the second magnetic sensor even when the magnetic resolution of the second magnetic sensor for detecting the soft magnetic material or the hard magnetic material is set lower than the magnetic resolution of the first magnetic sensor. Alternatively, the detection result of the hard magnetic material can be set to a magnetic resolution equivalent to the magnetic resolution of the first magnetic sensor.

FIG. 1 is a schematic diagram showing a schematic configuration of a paper sheet magnetic property evaluation apparatus according to the present invention. FIG. 2 is a diagram for explaining magnetic field setting according to the first embodiment in which only the hard magnetic material is detected by the second magnetic sensor. FIG. 3 is a schematic diagram illustrating a paper sheet, a first magnetic sensor, and a second magnetic sensor to be processed according to the first embodiment. FIG. 4 is a diagram illustrating an example in which the first magnetic sensor and the second magnetic sensor are formed of magnetoresistive elements. FIG. 5 is a diagram illustrating another example in which the first magnetic sensor and the second magnetic sensor are formed of magnetoresistive elements. FIG. 6 is a diagram illustrating detection results of the soft magnetic material and the hard magnetic material included in the paper sheet according to the first embodiment. FIG. 7 is a diagram for explaining magnetic field setting according to the second embodiment in which only the soft magnetic material is detected by the second magnetic sensor. FIG. 8 is a diagram illustrating a modification of the second magnetic sensor. FIG. 9 is a diagram illustrating the arrangement position of the second magnetic sensor. FIG. 10 is a diagram illustrating an example in which the configuration and arrangement position of the second magnetic sensor are different. FIG. 11 is a schematic diagram illustrating a different configuration example of the bias magnetic field magnet unit. FIG. 12 is a diagram for explaining an example in which both the soft magnetic material and the hard magnetic material are detected after detecting only the hard magnetic material. FIG. 13 is a diagram illustrating an example in which both the soft magnetic material and the hard magnetic material are detected after detecting only the soft magnetic material.

  Hereinafter, a paper sheet magnetic property evaluation apparatus and a paper sheet magnetic property evaluation method according to the present invention will be described in detail with reference to the accompanying drawings. Printed using both hard magnetic ink with high coercive force and soft magnetic ink with low coercive force, and magnetic threads made of hard magnetic material are embedded in the paper. There is something that was. Examples of paper sheets that use magnetic ink and magnetic threads include banknotes, gift certificates, and tickets. In the following, a case will be described in which paper sheets including soft magnetic ink, hard magnetic ink, and magnetic threads are to be processed.

  FIG. 1 is a schematic diagram showing an outline of a paper sheet magnetic property evaluation apparatus 1. FIG. 1 shows a view when the apparatus is viewed from the side (Y-axis negative direction side). The paper sheet magnetic property evaluation apparatus 1 includes a first magnetic sensor 10, a second magnetic sensor 20, a first bias magnetic field magnet unit 31, and a second bias magnetic field magnet unit 32. The first bias magnetic field magnet unit 31 and the second bias magnetic field magnet unit 32 generate a bias magnetic field in the transport path 40 through which the paper sheet 60 is transported. The magnetic material of the paper sheet 60 conveyed in the positive X-axis direction shown in FIG. 1 is magnetized by this bias magnetic field, and the first magnetic sensor 10 detects the magnetic material in the first detection region 51, In the second detection area 52, the second magnetic sensor 20 detects the magnetic material.

  The bias magnetic field generated by the first bias magnetic field magnet unit 31 and the second bias magnetic field unit 32 detects both the soft magnetic material and the hard magnetic material in the first detection region 51, and the soft magnetic material or the hard magnetic material in the second detection region 52. Only one of the hard magnetic materials is set to be detected. The second bias magnetic field magnet unit 32 is necessary when only the soft magnetic material is detected by the second magnetic sensor 20, but is not necessary when only the hard magnetic material is detected. The second bias magnetic field magnet unit 32 is indicated by a broken line. The bias magnetic field magnet units 31 and 32 may be composed of electromagnets. When an electromagnet is used, the magnetic field strength of the bias magnetic field can be controlled by controlling the current.

  The paper sheet magnetic property evaluation apparatus 1 according to the present invention uses two sensors, ie, a first magnetic sensor 10 and a second magnetic sensor 20, and a soft magnetic body and a hard magnetic body included in the paper sheet with one sensor. By detecting both of these and detecting only one of the soft magnetic material and the hard magnetic material with the other sensor, a detection result that distinguishes the soft magnetic material and the hard magnetic material on the paper sheet can be obtained. This is one feature. In the second magnetic sensor 20, there are a case where only the hard magnetic body is detected and a case where only the soft magnetic body is detected. In the following, in the first embodiment, only the hard magnetic body is detected by the second magnetic sensor 20. In the second embodiment, a case where only the soft magnetic material is detected by the second magnetic sensor 20 will be described.

  FIG. 2 is a diagram for explaining the operation of the paper sheet magnetic property evaluation apparatus 1 in which only the hard magnetic material is detected by the second magnetic sensor 20. In FIG. 2, the schematic configuration of the paper sheet magnetic property evaluation apparatus 1 is shown in the upper part, and the saturation magnetization curves of the soft magnetic material and the hard magnetic material included in the paper sheet 60 are shown in the lower part. In the paper sheet magnetic property evaluation apparatus 1, the first detection region 51 by the first magnetic sensor 10 corresponds to the saturation magnetization curves 501b and 502b, and the second detection region 52 by the second magnetic sensor 20 has the saturation magnetization curve 501c and It is configured to correspond to 502c.

  The first bias magnetic field magnet unit 31 magnetizes both the soft magnetic material and the hard magnetic material included in the paper sheet 60. Accordingly, in the first detection region 51, both the soft magnetic material and the hard magnetic material included in the paper sheet 60 are detected by the first magnetic sensor 10. That is, the first magnetic sensor 10 detects the magnetization corresponding to the saturation magnetization curves 501b and 502b shown in FIG.

  As shown in FIG. 2, since this apparatus does not include the second bias magnetic field magnet unit 32 shown in FIG. 1, residual magnetization is detected in the second detection region 52. As a result, in the second detection region 52, only the hard magnetic material is detected by the second magnetic sensor 20. That is, in the second magnetic sensor 20, as shown in FIG. 2, since the remanent magnetization 502c of the saturation magnetization curve of the soft magnetic material is substantially 0 (zero), the soft magnetic material is not detected and the hard magnetic material is saturated. Only the magnetization corresponding to the magnetization curve 501c is detected. Although description has been made using the saturation magnetization curve so far, if there is detectable residual magnetization, a magnetic material can be detected in the same manner as described above even when the magnetization curve forms a minor loop.

  In this way, both the soft magnetic material and the hard magnetic material are detected by the first magnetic sensor 10, and only the hard magnetic material is detected by the second magnetic sensor 20, so that the soft magnetic material and the hard magnetic material are distinguished. Can be detected. Below, the detection method of each magnetic body is demonstrated concretely.

  FIG. 3 is a view of the paper sheet 60 and the paper sheet magnetic evaluation apparatus 1 as viewed from above (Z-axis positive direction side). A sheet 60 shown in FIG. 3 includes a plurality of soft magnetic regions 70 printed using soft magnetic ink, a plurality of hard magnetic regions 80 printed using hard magnetic ink, and a magnetic thread made of a hard magnetic material. 90. Since the paper sheet 60 is transported in a short direction in the X-axis direction, the entire surface of the paper sheet can be scanned in a shorter time than when transported in the longitudinal direction. Hereinafter, the soft magnetic region and the hard magnetic region are referred to as a soft magnetic material and a hard magnetic material, respectively.

  As shown in FIG. 3, the first magnetic sensor 10 and the second magnetic sensor 20 are configured by disposing a plurality of magnetic detection elements 11 and 21 in the Y-axis direction, respectively. Signals detected using the magnetic detection elements 11 and 21 are processed by a signal processing circuit (not shown). In the signal processing circuit, for example, amplification processing, noise reduction processing, and A / D conversion processing are performed.

  The size and number of the magnetic detection elements 11 forming the first magnetic sensor 10 and the magnetic detection elements 21 forming the second magnetic sensor 20 in the Y-axis direction are the detection results of the necessary resolution according to the magnetic material to be detected. Is set to be obtained. For example, when a pattern or character is drawn with magnetic ink, the size and number of the magnetic detection elements are set so that a detection result capable of recognizing these is obtained. If only the presence or absence of the magnetic material needs to be detected, only one magnetic detection element may be disposed at a position where the magnetic material can be detected. In other words, the magnetic resolution in the Y-axis direction in the magnetic detection result is set based on the detection purpose, size, and shape of the magnetic substance to be detected, and the first magnetic sensor 10 and the second magnetic sensor are set according to the magnetic resolution. The size and number of the magnetic detection elements 11 and 21 included in 20 are set.

  Since the magnetic bodies to be detected are different between the first magnetic sensor 10 and the second magnetic sensor 20, the size and number of the magnetic detection elements 11 used in the first magnetic sensor 10 and the second magnetic sensor 20 are used. The size and number of the magnetic detection elements 21 are different. For example, as shown in FIG. 3, the first magnetic sensor 10 and the second magnetic sensor 20 have the same length in the Y-axis direction, but the first magnetic sensor 10 is formed by 16 magnetic detection elements 11. The second magnetic sensor 20 is formed by eight magnetic detection elements 21.

  Thus, when the magnetic resolution of the second magnetic sensor 20 is only half that of the first magnetic sensor 10, the number of the magnetic detection elements 21 forming the second magnetic sensor 20 is set to the first magnetic sensor 10. The number of the magnetic detection elements 11 forming can be half of the number. By setting the size and number of the magnetic detection elements based on the required magnetic resolution, the manufacturing cost of the paper sheet magnetic evaluation apparatus 1 can be suppressed.

  As the magnetic detection elements 11 and 21, a Hall element, a magneto-impedance element, a fluxgate element, an MR (Magneto Resistive) element or the like can be used. In the following, an anisotropic magnetoresistive (AMR) element is used. An example of the case will be described.

  FIG. 4 is a diagram illustrating the first magnetic sensor 10 formed using the AMR element 11. FIG. 4A shows a schematic structure of the first magnetic sensor 10 as viewed from above (Z-axis positive direction side). The first magnetic sensor 10 includes an AMR sensor 12 including an AMR element 11 that is a magnetosensitive element, and a mounting substrate 13 for mounting the AMR sensor 12. The first magnetic sensor 10 is arranged so that the magnetic sensing direction of the AMR element 11 is the X-axis direction so as to detect a magnetic body that passes above (Z-axis positive direction) in the X-axis direction. The signal output from each AMR sensor 12 is processed by a signal processing circuit provided in the paper sheet magnetic evaluation apparatus 1.

  FIG. 4B is a diagram illustrating an internal configuration of the AMR sensor 12. In the AMR sensor 12, the AMR element 11 is disposed so as to be approximately in the center of the mounting substrate 13 in the X-axis direction, and is connected to the terminals 12a and 12b. The terminals 12a and 12b of the AMR sensor 12 are connected so as to form a half-bridge type circuit shown in FIG. 4C by using a fixed resistor 14 included in the mounting substrate 13. Specifically, a voltage (+ V) is applied to the terminal 12 a to connect the terminal 12 b to one end of the fixed resistor 14 provided on the mounting substrate 13. Then, the other end of the fixed resistor 14 is grounded (GND), and the midpoint voltage of the half bridge composed of the AMR element 11 and the fixed resistor 14 when the magnetic material is detected is measured as the output voltage (Vout) at the terminal 12b. To do.

  Note that the structure of the AMR sensor 12 forming the first magnetic sensor 10 is not limited to a mode in which the fixed resistor 14 which is a magnetosensitive element is provided on the mounting substrate 13 as shown in FIG. 4B. . For example, as illustrated in FIG. 5A, the fixed resistor 14 may be included in the AMR sensor 12. As shown in FIG. 5B, the AMR element 11 and the fixed resistor 14 are connected inside the AMR sensor 12 to form a half bridge circuit as shown in FIG. Thereby, similarly to the AMR sensor 12 shown in FIG. 4, a magnetic body can be detected.

  The second magnetic sensor 20 differs from the first magnetic sensor 10 only in the size and number of AMR elements used in the Y-axis direction. Since other structures are the same as those of the first magnetic sensor 10, detailed description thereof is omitted.

  The first bias magnetic field magnet unit 31 shown in FIG. 2 has a function of magnetizing the soft magnetic body 70, the hard magnetic body 80 and the magnetic thread 90 included in the paper sheet 60. The structure of the first bias magnetic field magnet unit 31 is not particularly limited as long as a necessary bias magnetic field can be generated in the first detection region 51 which is a magnetic material detection region by the first magnetic sensor 10. For example, the first bias magnetic field magnet unit 31 may be configured only by a magnet such as a permanent magnet or an electromagnet, or may be configured using a magnet and a yoke.

  The measurement bias magnetic field of the first magnetic sensor 10 and the second magnetic sensor 20 formed using the AMR element 11 may be generated by the first bias magnetic field magnet unit 31. It may be generated using a magnet unit (not shown).

  The first bias magnetic field magnet unit 31 detects both the soft magnetic body 70 and the hard magnetic bodies 80 and 90 in the first magnetic sensor 10, and detects only the hard magnetic bodies 80 and 90 in the second magnetic sensor 20. Therefore, the soft magnetic body 70 is used to control the magnetization state of the paper sheet 60 so that it is not detected.

  Specifically, the first bias magnetic field magnet unit 31 includes a soft magnetic material 70 included in the paper sheet 60 and a hard magnetic material on the upstream side of the conveyance path 40 with respect to the first detection region 51 illustrated in FIG. Both bodies 80 and 90 are magnetized. As a result, in the first detection region 51, both the soft magnetic body 70 and the hard magnetic bodies 80 and 90 are detected by the first magnetic sensor 10.

  Next, the first bias magnetic field magnet unit 31 has a magnetic field that acts on the paper sheet 60 so that the residual magnetization in the soft magnetic body 70 having a small coercive force approaches approximately 0 (zero) in the second detection region 52. Is set to approximately 0 (zero). Thereby, in the second detection region 52, only the hard magnetic bodies 80 and 90 are detected by the second magnetic sensor 20. As for the bias magnetic field, if the soft magnetic material and the hard magnetic material can be distinguished and detected in the second detection region 52, the magnetization intensity of the soft magnetic material in the second detection region 52 is set to approximately 0 (zero). It is not limited to the embodiment.

  When the detection result by the first magnetic sensor 10 and the detection result by the second magnetic sensor 20 are obtained, the detection result is used to detect only the soft magnetic material, and the detection result is only the hard magnetic material. Can be obtained.

  FIG. 6 is a diagram for explaining the magnetic detection result obtained by the paper sheet magnetic property evaluation apparatus 1. FIG. 6A shows the paper sheet 60 to be detected, and FIG. 6B shows the first magnetic sensor 10 and the second magnetic sensor 20. FIG. 6C shows the detection result of the magnetic material by the first magnetic sensor 10, and FIG. 6D shows the detection result of only the hard magnetic material by the second magnetic sensor 20. FIGS. 6E and 6F show the magnetic substance detection results finally obtained by using the detection results obtained by the first magnetic sensor 10 and the second magnetic sensor 20. FIG. 6E shows the detection result including only the soft magnetic material, and FIG. 6F shows the detection result including only the hard magnetic material. In the example of FIG. 6, the paper sheet 60 in which the hard magnetic material and the soft magnetic material do not coexist is shown in one detection area by the second magnetic sensor 20 having a low resolution among the two magnetic sensors. The embodiment is not limited to this, and the structures of the first magnetic sensor 10 and the second magnetic sensor 20 are determined according to the distribution of the magnetic material contained in the paper sheet 60 to be detected.

  6A to 6F are illustrated so that the positional relationship between the paper sheet 60 and the first magnetic sensor 10 and the second magnetic sensor 20 can be understood. For example, in FIG. 6, the result of detecting the soft magnetic body 70 on the left side of the magnetic thread 90 shown in FIG. 6A by the AMR elements 11 a and 11 b shown in FIG. This is a region 170a. Further, for example, the result of detecting the magnetic thread 90 shown in FIG. 5A by the AMR element 11c shown in FIG. 5B is a region 190a in FIG. 5C, and the AMR shown in FIG. The result detected by the element 21a is a region 190b in FIG.

  FIG. 6C shows the detection result of the magnetic material by the first magnetic sensor 10. As described above, the detection results by the first magnetic sensor 10 include the areas 170a and 170b where the soft magnetic body 70 printed with the soft magnetic ink is detected, and the areas where the hard magnetic body 80 printed with the hard magnetic ink is detected. 180 and a region 190a in which a magnetic thread 90 made of a hard magnetic material is detected is included. That is, both the soft magnetic body 70 and the hard magnetic bodies 80 and 90 included in the paper sheet 60 are detected.

  FIG. 6D shows the detection result of the magnetic material by the second magnetic sensor 20. Thus, the detection result by the second magnetic sensor 20 does not include the area where the soft magnetic body 70 is detected, but includes only the area 180 where the hard magnetic body 80 is detected and the area 190b where the magnetic thread 90 is detected. .

  FIG. 6E is a diagram showing a detection result of only the soft magnetic material. In the paper sheet magnetic property evaluation apparatus 1, the result of detecting both the soft magnetic material and the hard magnetic material shown in FIG. 6C and the result of detecting only the hard magnetic material shown in FIG. Compare these. Then, by obtaining a difference area obtained by subtracting the area obtained in FIG. 6D from the area obtained in FIG. 6C, the detection corresponding to the soft magnetic body 70 as shown in FIG. Only the regions 170a and 170b can be extracted.

  Specifically, by removing the detection region in FIG. 6D in which only the hard magnetic body 80 is detected from the detection region in FIG. 6C in which both the soft magnetic body 70 and the hard magnetic body 80 are detected, The result shown in FIG. 5E can be obtained.

  At this time, in the second magnetic sensor 20, the magnetic thread 90 is detected by the AMR element 21a shown in FIG. For this reason, as shown in FIG. 6D, the width in the Y-axis direction of the region 190b in which the magnetic thread 90 is detected is wider than the actual width of the magnetic thread 90 shown in FIG. However, since the region including only the hard magnetic material cannot be larger than the region including both the soft magnetic material and the hard magnetic material, the paper sheet magnetic property evaluation apparatus 1 uses the magnetic detection element 21. Recognize it as an effect. Thereby, the result which shows the distribution state of the soft-magnetic body shown to the same figure (e) can be obtained as a difference area | region which deducted the detection area | region of the same figure (d) from the detection area | region of FIG.6 (c). That is, only the region corresponding to the region 190a in FIG. 6C among the region 190b in FIG. 6D is the result of detecting the hard magnetic material, and the difference region between FIG. 6C and FIG. To decide.

  FIG. 6F is a diagram showing the detection result of only the hard magnetic material. The sheet magnetic property evaluation apparatus 1 compares the detection results of the soft magnetic material and the hard magnetic material shown in FIG. 6C with the detection result of the hard magnetic material shown in FIG. The detection regions 180 and 190a of the hard magnetic body 80 shown in f) can be obtained. In the second magnetic sensor 20, as shown in FIG. 6D, the magnetic thread 90 is detected with a width wider than the actual width. However, the paper sheet magnetic property evaluation apparatus 1 compares the detection results of FIGS. 6C and 6D so that the region 190b of FIG. 6D is detected in a wide range due to the influence of the AMR element 21. The region 190a is adopted instead of the region 190b as the detection result of the magnetic thread 90. Thereby, as a detection result of the hard magnetic material, not the result of FIG. 6D in which the second magnetic sensor 20 detects the hard magnetic material, but the detection result indicating the distribution state of the hard magnetic material shown in FIG. Can be obtained.

  As described above, the magnetic resolution of the second magnetic sensor 20 that detects only the hard magnetic material is set to be lower than the magnetic resolution of the first magnetic sensor 10, but by using the detection result of the first magnetic sensor 10. In the detection result of the hard magnetic material, the same resolution as that of the first magnetic sensor 10 can be obtained.

  In the present embodiment, the case where only the hard magnetic material is detected by the second magnetic sensor 20 has been described, but the same description can be made even when only the soft magnetic material is detected.

  While controlling the magnetization state of the magnetic bodies 70 to 90 included in the paper sheet 60, both the soft magnetic body and the hard magnetic body are detected by the first magnetic sensor 10, and only the hard magnetic body is detected by the second magnetic sensor 20. By detecting this, it is possible to distinguish and detect the soft magnetic material and the hard magnetic material contained in the paper sheet. This result can be used to identify the type and authenticity of the paper sheet 60.

    FIG. 7 is a diagram for explaining the operation of the paper sheet magnetic property evaluation apparatus 1 in which only the soft magnetic material is detected by the second magnetic sensor 20. The present embodiment is different from the first embodiment in that the magnetizing magnet unit 36 and the second bias magnetic field magnet unit 32 are used to detect soft magnetism by the second magnetic sensor 20.

  In FIG. 7, the schematic configuration of the paper sheet magnetic evaluation apparatus 1 is shown at the top, and the saturation magnetization curves of the soft magnetic material and the hard magnetic material included in the paper sheet 60 are shown at the bottom. In this paper sheet magnetic property evaluation apparatus 1, the saturation magnetization region by the magnetizing magnet unit 36 corresponds to the saturation magnetization curves 501a and 502a, and the first detection region 51 by the first magnetic sensor 10 has the saturation magnetization curve 501b and Corresponding to 502b, the second detection region 52 by the second magnetic sensor 20 is configured to correspond to the saturation magnetization curves 501c and 502c.

  First, in the saturation magnetization region on the upstream side of the transport path 40 with respect to the first magnetic sensor 10 and the second magnetic sensor 20 corresponding to 501a and 502a shown in the saturation magnetization curve in the lower part of FIG. Both the soft magnetic material and the hard magnetic material included in the paper sheet 60 are in a saturated magnetization state. Next, in the first detection region 51, both the soft magnetic material and the hard magnetic material included in the paper sheet 60 are detected by the first magnetic sensor 10. Here, the first magnetic sensor 10 detects the magnetization corresponding to the saturation magnetization curves 501b and 502b shown in FIG. 7 according to the magnetic field intensity of the bias magnetic field by the first bias magnetic field magnet unit 31.

  As for the soft magnetic material, when the paper sheet 60 in the saturated magnetization state is transported in the positive direction of the X axis in the transport path 40, first, in the first detection region 51, the saturation magnetization curve of the first magnetic sensor 10 is displayed. Magnetization corresponding to 502b is detected. Subsequently, in the second detection region 52, the magnetization corresponding to the saturation magnetization curve 502c is detected by the second magnetic sensor 20.

  On the other hand, with respect to the hard magnetic material, in the first detection region 51, the magnetization corresponding to the saturation magnetization curve 501b is detected by the first magnetic sensor 10. However, in the second detection region 52, the paper sheet 60 is set so that the magnetization intensity of the hard magnetic material becomes substantially 0 (zero) as indicated by the saturation magnetization curve 501c by the bias magnetic field generated by the second bias magnetic field magnet unit 32. The magnetization state of is controlled. For this reason, no hard magnetic material is detected in the second detection region 52.

  In other words, in the paper sheet magnetic property evaluation apparatus 1 according to the present embodiment, the first magnetic sensor 10 uses the magnetism magnet unit 36, the first bias magnetic field magnet unit 31, and the second bias magnetic field magnet unit 32 to perform soft magnetism. Both the body and the hard magnetic body are detected, and the magnetization state of the paper sheet 60 is controlled so that only the soft magnetic body is detected by the second magnetic sensor 20.

  In addition, in order to set the magnetization intensity of the hard magnetic body to approximately 0 (zero) at the position where the second magnetic sensor 20 is disposed, the magnetic characteristics of the soft magnetic body and the hard magnetic body included in the paper sheet 60 are grasped. Therefore, it is necessary to perform magnetic field control based on the saturation magnetization curve as shown in FIG. For this reason, the method of detecting the soft magnetic material and the hard magnetic material by the first magnetic sensor 10 and detecting only the soft magnetic material by the second magnetic sensor 20 is to evaluate the magnetic properties of the paper sheet 60 with clear magnetic characteristics. Limited to the case where it is performed.

  In this way, the first magnetic sensor 10 detects the soft magnetic material and the hard magnetic material, and the second magnetic sensor 20 detects only the soft magnetic material, so that the soft magnetic material and the hard magnetic material are detected as in the first embodiment. Magnetic materials can be distinguished and detected.

Modified example

  The structure of the 1st magnetic sensor 10 and the 2nd magnetic sensor 20 is not limited to the aspect shown in Example 1 and Example 2, The detection purpose of the magnetic body contained in the paper sheets 60, a magnetic body Is appropriately set depending on the size of the paper and the position on the paper sheet. Hereinafter, modifications of the sensor structure shown in FIGS. 8 to 11 will be described based on Example 1 in which only the hard magnetic material is detected by the second magnetic sensor 20, but these are also described in Example 2. Applicable.

  FIG. 8 is a diagram illustrating examples of different structures of the first magnetic sensor 10 and the second magnetic sensor 20. For example, when the paper sheet 60 shown in FIG. 8A is a detection target, the size and the paper sheet 60 of the hard magnetic material 80 printed with the hard magnetic ink and the magnetic thread 90 made of the hard magnetic material are determined. It is not necessary to detect the position above, and it may be only necessary to detect whether or not the hard magnetic bodies 80 and 90 are present. In such a case, as shown in FIG. 8B, the second magnetic sensor 20 that detects the hard magnetic bodies 80 and 90 may be formed of only one AMR element 21.

  Further, when the position where the hard magnetic bodies 80 and 90 included in the paper sheet 60 are detected is limited to the position shown in FIG. 8A, as shown in FIG. The size in the Y-axis direction of the AMR element 21 that detects 80 and 90 may be set so as to include the detection positions of the hard magnetic bodies 80 and 90, and the size in the Y-axis direction of the second magnetic sensor 20 may be reduced. . That is, the length in the Y-axis direction of the detection area in which the second magnetic sensor 20 detects the magnetic material may be shorter than that of the first magnetic sensor 10.

  The size and number of the AMR elements 11 and 21 forming the magnetic sensors 10 and 20 are appropriately set according to the magnetic material to be detected. The sizes of the magnetic sensors 10 and 20 are also set as appropriate according to the size of the paper sheet 60 and the size and position of the magnetic material included in the paper sheet 60. Note that when determining the structure of the magnetic sensors 10 and 20, all paper sheets to be processed are taken into consideration.

  Further, when determining the structures of the magnetic sensors 10 and 20, the conveyance state of the paper sheets is also taken into consideration. For example, when the paper sheets 60 are not always transported with either the front surface or the back surface facing upward, but are transported with the front surface facing upward or the back surface facing upward. Considering this, the structures of the first magnetic sensor 10 and the second magnetic sensor 20 are determined.

  FIG. 9 shows the first magnetic sensor 10 and the first magnetic sensor 10 in consideration of the paper sheet 61a that is transported with the front surface facing upward and the paper sheet 61b that is transported with the back surface upward. It is a figure which shows the example in which the structure and arrangement position of 2 magnetic sensors 20 are determined. The paper sheets 61a and 61b include a soft magnetic material 70 printed with soft magnetic ink and a magnetic thread 90 made of a hard magnetic material. Since it is only necessary to detect whether or not the magnetic sled 90 is included in the hard magnetic material, the second magnetic sensor 20 is configured to include only one AMR element 21. The Y axis of the AMR element 21 can be detected so that the presence or absence of the magnetic thread 90 can be detected in both cases of the paper sheet 61a conveyed with the front surface upward and the bill 61b conveyed with the back surface upward. The direction size and placement position are determined.

  FIG. 10 is a diagram showing an example of the second magnetic sensor 20 set to detect the hard magnetic material 80 printed with the hard magnetic ink in addition to the magnetic thread 90. The paper sheet 62a shows a state in which the front surface is conveyed upward, and the paper sheet 62b shows a state in which the rear surface is conveyed upward. As in the case of FIG. 9, the second magnetic sensor 20 includes a sensor 20a including one AMR element 21a in order to detect the presence or absence of the magnetic thread 90.

  In addition to this, the second magnetic sensor 20 includes sensors 20b and 20c in order to detect the hard magnetic body 80 regardless of the front and back of the paper sheet. That is, the second magnetic sensor 20 is configured by three magnetic sensors 20a to 20c. In addition, in order to detect not only the presence / absence of the hard magnetic material 80 but also the position and size of the print area using hard magnetic ink, each magnetic sensor 20b and 20c is formed by a plurality of AMR elements 21b and 21c. Yes.

  As described above, the second magnetic sensor 20 that detects only the hard magnetic body is configured to detect only the presence or absence of the hard magnetic body or to be disposed only in the region where the hard magnetic body is present. The number can be reduced and the sensor size can be reduced. As a result, the manufacturing cost of the paper sheet magnetic property evaluation apparatus 1 can be reduced, and the size of the apparatus can be reduced.

  Also, with respect to the configuration of the first bias magnetic field magnet unit 31 and the second bias magnetic field magnet unit 32, it is possible to set a bias magnetic field for controlling the magnetization state of the soft magnetic material and the hard magnetic material as described above. If possible, the present invention is not limited to the modes shown in the first and second embodiments.

  FIG. 11 is a schematic diagram illustrating a different configuration example of the first bias magnetic field magnet unit 31 illustrated in FIG. 2. As described above, the magnets 33a and 33b arranged on the upstream side (X-axis negative direction side) of the transport path 40 with respect to the first magnetic sensor 10 and the second magnetic sensor 20, and the downstream side (X-axis positive direction side). The first bias magnetic field magnet unit 31 may be formed by the magnets 35a and 35b arranged on the upper side and the yokes 34a and 34b connecting the upstream side magnet and the downstream side magnet.

  In the first embodiment and the second embodiment, first, both the soft magnetic material and the hard magnetic material are detected by the first magnetic sensor 10, and then the second magnetic resolution is lower than that of the first magnetic sensor 10. The case where either the soft magnetic material or the hard magnetic material is detected by the magnetic sensor 20 is shown. However, the method for detecting the magnetic material is not limited to this, and the second magnetic sensor 20 detects only one of the soft magnetic material and the hard magnetic material, and then the first magnetic sensor. 10 may detect both the soft magnetic material and the hard magnetic material.

  FIG. 12 is a diagram for explaining the paper sheet magnetic property evaluation apparatus 1 in which only the hard magnetic material is detected by the second magnetic sensor 20 and then both the soft magnetic material and the hard magnetic material are detected by the first magnetic sensor 10. It is. The arrangement positions of the first magnetic sensor 10, the second magnetic sensor 20, and the first bias magnetic field magnet unit 31 are different from those of the first embodiment shown in FIG. Moreover, the point which has the magnetizing magnet unit 36 in the upstream (X-axis negative direction side) of the conveyance path 40 differs from Example 1. FIG.

  In FIG. 12, an outline of the configuration of the paper sheet magnetic property evaluation apparatus 1 is shown in the upper part, and a saturation magnetization curve of the soft magnetic material and the hard magnetic material included in the paper sheet 60 is shown in the lower part. In this sheet magnetic property evaluation apparatus 1, the magnetizing magnet unit 36 corresponds to the saturation magnetization curves 501 a and 502 a, the second magnetic sensor 20 corresponds to the saturation magnetization curves 501 c and 502 c, and the first magnetic sensor 10. Is configured to correspond to the saturation magnetization curves 501d and 502d.

  First, on the upstream side of the transport path 40 with respect to the first magnetic sensor 10 and the second magnetic sensor 20, both the soft magnetic material and the hard magnetic material included in the paper sheet 60 are saturated and magnetized by the magnetizing magnet unit 36. . Thereafter, only the hard magnetic material contained in the paper sheet 60 is detected by the second magnetic sensor 20 first. No bias magnetic field is generated at the position where the second magnetic sensor 20 is disposed. Therefore, as shown in FIG. 12, in the second magnetic sensor, the residual magnetization of the saturation magnetization curve 502c of the soft magnetic material is substantially 0 (zero), so that the soft magnetic material is not detected and the hard magnetic material is saturated. Only the magnetization corresponding to the magnetization curve 501c is detected.

  Thereafter, both the soft magnetic material and the hard magnetic material included in the paper sheet 60 are detected by the first magnetic sensor 10. At the position where the first magnetic sensor 10 is disposed, a bias magnetic field is generated by the first bias magnetic field magnet unit 31. For this reason, as shown in FIG. 12, the first magnetic sensor 10 detects magnetization corresponding to the saturation magnetization curves 501d and 502d in accordance with the magnetic field strength of the bias magnetic field.

  FIG. 13 is a diagram for explaining the paper sheet magnetic evaluation apparatus 1 in which only the soft magnetic material is detected by the second magnetic sensor 20 and then both the soft magnetic material and the hard magnetic material are detected by the first magnetic sensor 10. It is. The arrangement positions of the first magnetic sensor 10, the second magnetic sensor 20, the first bias magnetic field magnet unit 31, and the second bias magnetic field magnet unit 32 are different from those of the second embodiment shown in FIG. In this embodiment, the saturation magnetization curve is used for explanation. However, if there is detectable residual magnetization, the magnetic material can be detected in the same manner as described above even if the magnetization curve forms a minor loop. Can do.

  In FIG. 13, the schematic configuration of the paper sheet magnetic evaluation apparatus 1 is shown at the top, and the saturation magnetization curves of the soft magnetic material and the hard magnetic material included in the paper sheet 60 are shown at the bottom. In this sheet magnetic property evaluation apparatus 1, the magnetizing magnet unit 36 corresponds to the saturation magnetization curves 501 a and 502 a, the second magnetic sensor 20 corresponds to the saturation magnetization curves 501 c and 502 c, and the first magnetic sensor 10. Is configured to correspond to the saturation magnetization curves 501d and 502d.

  First, on the upstream side of the transport path 40 with respect to the first magnetic sensor 10 and the second magnetic sensor 20, both the soft magnetic material and the hard magnetic material included in the paper sheet 60 are saturated and magnetized by the magnetizing magnet unit 36. . Thereafter, only the soft magnetic material included in the paper sheet 60 is detected by the second magnetic sensor 20. At the position where the second magnetic sensor 20 is disposed, a bias magnetic field is generated by the second bias magnetic field magnet unit 32. The bias magnetic field is set so that the magnetization intensity of the hard magnetic material included in the paper sheet 60 is substantially 0 (zero). For this reason, as shown in FIG. 13, in the second magnetic sensor 20, the magnetization of the saturation magnetization curve 501c of the hard magnetic material becomes substantially 0 (zero) and the hard magnetic material is not detected, and the soft magnetic material is saturated. Only the magnetization corresponding to the magnetization curve 502c is detected.

    Thereafter, both the soft magnetic material and the hard magnetic material included in the paper sheet 60 are detected by the first magnetic sensor 10. At the position where the first magnetic sensor 10 is disposed, a bias magnetic field is generated by the first bias magnetic field magnet unit 31. For this reason, as shown in FIG. 13, in the first magnetic sensor 10, magnetization corresponding to the saturation magnetization curves 501d and 502d is detected according to the magnetic field strength of the bias magnetic field.

  As described above, even when the detection order of the magnetic material is different from that in Example 1 and Example 2, the result of detecting the soft magnetic material and the hard magnetic material and only one of the soft magnetic material and the hard magnetic material was detected. If the result can be obtained, finally, as in the case of Example 1, the detection result in which the soft magnetic material and the hard magnetic material are distinguished can be obtained.

  As described above, according to the present embodiment, the first magnetic sensor 10 and the second magnetic sensor 20 are used to detect both the soft magnetic material and the hard magnetic material on the one hand, and the soft magnetic material on the other hand. Alternatively, by detecting either the hard magnetic material, the soft magnetic material and the hard magnetic material contained in the paper sheet can be distinguished and detected. Further, the size of the magnetic sensor is reduced by reducing the size or reducing the number of the magnetic detection elements included in the magnetic sensor according to the magnetic material to be detected, thereby reducing the size of the magnetic sensor. The manufacturing cost and the apparatus size can be suppressed.

  Further, even when the magnetic resolution of the second magnetic sensor 20 that detects the soft magnetic material or the hard magnetic material is set lower than the magnetic resolution of the first magnetic sensor 10, the detection result by the first magnetic sensor 10 is used. The detection result of the soft magnetic material or hard magnetic material detected by the second magnetic sensor 20 can be set to a magnetic resolution equivalent to the magnetic resolution of the first magnetic sensor 10.

  As described above, the present invention is a useful technique for distinguishing and detecting soft magnetic materials and hard magnetic materials from paper sheets containing both soft magnetic materials and hard magnetic materials.

DESCRIPTION OF SYMBOLS 1 Paper sheet magnetism evaluation apparatus 10 1st magnetic sensor 11, 21 Magnetic detection element 11a-11f, 21a-21c Magnetic detection element (AMR element)
12 Magnetic sensor 13 Mounting substrate 14 Fixed resistance 20, 20a to 20c Second magnetic sensor 31, 32 Bias magnetic field magnet unit 33a, 33b, 35a, 35b Magnet 34 Yoke 36 Magnetizing magnet unit 40 Transport path 60, 61a, 61b 62a, 62b Paper 70 Soft magnetic material 80 Hard magnetic material 90 Magnetic thread

Claims (12)

In the conveyance path where paper sheets are conveyed,
A first detection region that generates a bias magnetic field in the region of the transport path and magnetizes both the soft magnetic material and the hard magnetic material included in the paper sheet;
A second detection region that enables detection of either the hard magnetic body or the soft magnetic body in a different area from the first detection area by the intensity of the bias magnetic field so as to be distinguishable from the other;
Further, a plurality of magnetic detection elements arranged in a line in the first detection region are arranged to scan the paper sheets, and both the soft magnetic body and the hard magnetic body included in the paper sheets are A first magnetic sensor to detect;
In the second detection region, a smaller number of magnetic detection elements than the number of the magnetic detection elements forming the first magnetic sensor are arranged, the paper sheets are scanned, and the soft sheets included in the paper sheets are scanned. And a second magnetic sensor that detects only one of the magnetic body and the hard magnetic body at a lower resolution than the first magnetic sensor. The bias magnetic field is
In the first detection region, using a first bias magnetic field magnet unit for magnetizing both the soft magnetic material and the hard magnetic material included in the paper sheet,
The second detection area is provided on the downstream side of the first detection area, and the bias magnetic field magnet unit is not used for detecting only the hard magnetic body with the magnetization intensity of the soft magnetic body set to 0 (zero). ,
2. The paper sheet magnetic evaluation apparatus according to claim 1, wherein the second magnetic sensor detects only the hard magnetic material included in the paper sheet. 2. The paper sheet according to claim 1, further comprising a magnetizing magnet unit that saturates and magnetizes the paper sheet upstream of the transport path with respect to the first detection area and the second detection area. Magnetic evaluation device. The bias magnetic field is
In the first detection region, using a first bias magnetic field magnet unit for magnetizing both the soft magnetic material and the hard magnetic material included in the paper sheet,
The second detection region is provided on the downstream side of the first detection region, and a second bias magnetic field magnet unit is used to detect only the soft magnetic material by setting the magnetization intensity of the hard magnetic material to 0 (zero). And
4. The paper sheet magnetic evaluation apparatus according to claim 3, wherein the second magnetic sensor detects only the soft magnetic material included in the paper sheet. 5. The bias magnetic field is
In the first detection region, using a first bias magnetic field magnet unit for magnetizing both the soft magnetic material and the hard magnetic material included in the paper sheet,
The second detection area is provided on the upstream side of the first detection area, and the bias magnetic field magnet unit is not used to detect only the hard magnetic body with the magnetization intensity of the soft magnetic body set to 0 (zero). Because
The paper magnetic evaluation apparatus according to claim 3, wherein the second magnetic sensor detects only the hard magnetic material included in the paper. The bias magnetic field is
In the first detection region, using a first bias magnetic field magnet unit for magnetizing both the soft magnetic material and the hard magnetic material included in the paper sheet,
The second detection region is provided on the upstream side of the first detection region, and a second bias magnetic field magnet unit is used to detect only the soft magnetic material by setting the magnetization intensity of the hard magnetic material to 0 (zero). And
2. The paper sheet magnetic evaluation apparatus according to claim 1, wherein the second magnetic sensor detects only the soft magnetic material included in the paper sheet.   The sheet magnetic property evaluation apparatus according to claim 1, wherein the second magnetic sensor provided in the second detection region is configured by one magnetic detection element.   The second magnetic sensor provided in the second detection area has a detection area shorter than the first magnetic sensor, and is a detection target of the soft magnetic body or the hard magnetic body included in the paper sheet. The paper sheet magnetic evaluation apparatus according to claim 1, wherein the paper magnetic evaluation apparatus is arranged at a position corresponding to the magnetic body.   9. The paper magnetism according to claim 8, wherein the second magnetic sensor provided in the second detection region is configured by a plurality of magnetic sensors having a detection region shorter than the first magnetic sensor. Evaluation device. Magnetizing both a soft magnetic material and a hard magnetic material contained in the paper sheet by generating a bias magnetic field in a conveyance path through which the paper sheet is conveyed, and scanning the magnetized paper sheet, A first magnetic detection step of detecting both a soft magnetic material and a hard magnetic material contained in the paper sheet by a first magnetic sensor;
A second magnetic detection step of scanning the paper sheet in a region without the bias magnetic field and detecting only the hard magnetic material contained in the paper sheet by a second magnetic sensor having a lower resolution than the first magnetic sensor. A method for evaluating the magnetic properties of paper sheets, comprising: A magnetization step that generates a bias magnetic field in the transport path through which the paper sheet is transported to saturate both the soft magnetic material and the hard magnetic material contained in the paper sheet, and a bias in the transport path through which the paper sheet is transported A magnetic field is generated to magnetize both the soft magnetic material and the hard magnetic material included in the paper sheet, the magnetized paper sheet is scanned, and the first magnetic sensor includes the paper sheet. A first magnetic detection step for detecting both a soft magnetic material and a hard magnetic material;
A bias magnetic field having a predetermined strength is generated to magnetize only the soft magnetic material included in the paper sheet, and the magnetized paper sheet is scanned, so that the resolution is lower than that of the first magnetic sensor . And a second magnetic detection step of detecting only the soft magnetic material contained in the paper sheet by a two-magnetic sensor. Based on the detection result of the magnetic material of the soft magnetic material and the hard magnetic material obtained by the first magnetic sensor and the detection result of the magnetic material of the soft magnetic material or the hard magnetic material obtained by the second magnetic sensor. A detection result calculation step of calculating a detection result of the hard magnetic body or the soft magnetic body that is not detected by the second magnetic sensor,
When targeting the paper sheets distributed in a state where the distribution areas of the two types of magnetic bodies do not overlap in the unit detection area of the second magnetic sensor,
In the detection result calculation step, the detection result of the hard magnetic body and the soft magnetic body of the first magnetic sensor in the detection target area of the second magnetic sensor and detection of the magnetic body to be detected by the second magnetic sensor The detection result of the first magnetic sensor is separated into a detection result indicating the distribution state of the hard magnetic material and a detection result indicating the distribution of the soft magnetic material by comparing the result with the result. Or the paper sheet magnetic property evaluation method of 11.

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