JP2020008421A - Magnetism sensor - Google Patents

Abstract

To provide a magnetism sensor with which it is possible to correctly refresh a magnetic pattern having a high coercive force while suppressing an increase in cost to a minimum.SOLUTION: Provided is a magnetism sensor for scanning a measurement object member having a magnetic pattern in a direction y and thereby reading the magnetic pattern, comprising a plurality of unit magnetism sensors arrayed in a direction x and respectively having a permanent magnet. The plurality of unit magnetism sensors include unit magnetism sensors 10, 20 differing in the magnetic force of the permanent magnet from each other. According to the present invention, the unit magnetism sensor 10 including an inexpensive permanent magnet having a weak magnetic force is allocated to a section for scanning a magnetic pattern having a weak coercive force and the unit magnetism sensor 20 including a permanent magnet having a strong magnetic force is allocated to a section for scanning a magnetic pattern having a strong coercive force, so that it is possible to reduce material costs and detect the magnetic pattern stably.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetic sensor, and more particularly, to a magnetic sensor that reads a magnetic pattern by scanning a member to be measured such as a bill in a uniaxial direction.

  2. Description of the Related Art Magnetic sensors described in Patent Documents 1 and 2 are known as a type of magnetic sensor that scans a member to be measured such as a bill in a uniaxial direction. The magnetic sensors described in Patent Literatures 1 and 2 have a configuration in which a plurality of magnetic detection elements are arranged in one direction, and a member to be measured such as a bill is arranged in a direction orthogonal to the arrangement direction of the magnetic detection elements. By scanning, the magnetic pattern embedded in the member to be measured can be read.

  The magnetic sensors described in Patent Literatures 1 and 2 each include a permanent magnet disposed so as to overlap a magnetic detection element, and thereby apply a bias magnetic field to a member to be measured.

Japanese Utility Model Publication No. 2-7584 JP 2004-317463 A

  However, depending on the member to be measured, a magnetic pattern having a strong holding force and a magnetic pattern having a weak holding force may be mixed. In this case, if the magnetic force of the permanent magnet assigned to each of the plurality of magnetic detection elements is weak, the magnetic pattern having a strong coercive force will not be refreshed correctly, and detection may be performed in a state where the past magnetization history remains. there were. In order to solve this problem, a method of using a strong permanent magnet as the permanent magnet assigned to each of the plurality of magnetic detection elements can be considered. However, since the strong permanent magnet is expensive, the material cost is low. There was a problem of increasing.

  Accordingly, the present invention provides a magnetic sensor that reads a magnetic pattern by scanning a member to be measured in which a magnetic pattern having a high coercive force and a magnetic pattern having a low coercive force can coexist, while minimizing an increase in material cost, An object of the present invention is to correctly refresh a magnetic pattern having a strong coercive force and to stably detect a magnetic pattern.

  A magnetic sensor according to the present invention is a magnetic sensor that reads a magnetic pattern by scanning a member to be measured having a magnetic pattern in a first axis direction, and is arranged in a second axis direction different from the first axis direction. A plurality of unit magnetic sensors having permanent magnets are provided, and the plurality of unit magnetic sensors include first and second unit magnetic sensors having different permanent magnet magnetic forces.

  According to the present invention, since the first and second unit magnetic sensors having permanent magnets having different magnetic forces are provided, an inexpensive permanent magnet having a weak magnetic force is used in a portion for scanning a magnetic pattern having a weak coercive force. By assigning a unit magnetic sensor that has a strong magnetic force and allocating a unit magnetic sensor that has a permanent magnet with a strong magnetic force to the part that scans a magnetic pattern with a strong coercive force, the magnetic pattern with a strong coercive force is correctly refreshed while reducing material costs It is possible to detect the magnetic pattern stably.

  In the present invention, the permanent magnet included in the second unit magnetic sensor has a stronger magnetic force than the permanent magnet included in the first unit magnetic sensor, and the magnetic force of the first unit magnetic sensor is larger than that of the second unit magnetic sensor. It does not matter if the number is larger. According to this, it is possible to scan a wide range of the member to be measured by the plurality of unit first magnetic sensors while further reducing the material cost.

  In the present invention, the first and second unit magnetic sensors may have the same width in the second axis direction, or may have different widths in the second axis direction. According to the former, the area scanned by one magnetic sensor can be fixed regardless of the combination of the first unit magnetic sensor and the second unit magnetic sensor. According to the latter, it is possible to optimize the positions of the first and second unit magnetic sensors according to the positions of the magnetic patterns provided on the member to be measured.

  The magnetic sensor according to the present invention may further include a dummy housing block arranged in the second axis direction together with the first and second unit magnetic sensors. According to this, the cost can be further reduced by using the dummy housing block at a position where it is known in advance that the magnetic pattern does not exist. In this case, the width of the dummy housing block in the second axis direction may be the same as or different from the width of the unit magnetic sensor in the second axis direction.

  In the present invention, the first and second unit magnetic sensors have a sensor chip having a magnetic detection element, and the permanent magnets are viewed from a third axial direction orthogonal to the first axial direction and the second axial direction. It may be arranged so as to overlap with the sensor chip, or may be arranged so as to sandwich the sensor chip from the first axial direction. In any of the configurations, it is possible to apply a bias magnetic field to the sensor chip using a permanent magnet.

  As described above, according to the present invention, in a magnetic sensor capable of scanning a member to be measured in which a magnetic pattern having a strong holding force and a magnetic pattern having a weak holding force can coexist, it is possible to minimize an increase in material cost while maintaining a minimum. A strong magnetic pattern can be correctly refreshed, and the magnetic pattern can be detected stably.

FIG. 1 is a schematic perspective view showing the appearance of a magnetic sensor 1 according to a first embodiment of the present invention in a transparent manner. FIG. 2 is a schematic perspective view showing the appearance of the first unit magnetic sensor 10 in a transparent manner. FIG. 3 is a schematic perspective view showing the appearance of the second unit magnetic sensor 20 in a transparent manner. FIG. 4 is a schematic diagram illustrating an example of a bill 40 that is a member to be measured. FIG. 5A is a graph showing the magnetic characteristics of the magnetic pattern 41 having a weak coercive force, and FIG. 5B is a graph showing the magnetic characteristics of the magnetic pattern 42 having a strong coercive force. FIG. 6 is a schematic diagram illustrating an example in which the short direction of the banknote 40 is set as the scanning direction. FIG. 7 is a schematic diagram illustrating an example in which the longitudinal direction of the bill 40 is set as the scanning direction. FIG. 8 is a schematic perspective view showing the appearance of a first unit magnetic sensor 10A according to a modification transparently. FIG. 9 is a schematic perspective view showing the appearance of a second unit magnetic sensor 20A according to a modification transparently. FIG. 10 is a schematic perspective view showing the appearance of a magnetic sensor 1A in which a plurality of unit magnetic sensors 10A and 20A are connected in the x direction. FIG. 11 is a schematic perspective view showing the appearance of the magnetic sensor 2 according to the second embodiment of the present invention in a transparent manner. FIG. 12 is a schematic perspective view that transparently shows the appearance of a magnetic sensor 2A according to a modification. FIG. 13 is a schematic perspective view showing the appearance of the magnetic sensor 3 according to the third embodiment of the present invention transparently. FIG. 14 is a schematic perspective view showing the appearance of a magnetic sensor 4 according to a fourth embodiment of the present invention transparently. FIG. 15 is a schematic perspective view showing the appearance of a magnetic sensor 5 according to a fifth embodiment of the present invention transparently. FIG. 16 is a schematic perspective view showing the appearance of the first unit magnetic sensor 10B in a transparent manner. FIG. 17 is a schematic perspective view showing the appearance of the second unit magnetic sensor 20B transparently. FIG. 18 is a schematic perspective view showing the appearance of a magnetic sensor 6 according to a sixth embodiment of the present invention transparently. FIG. 19 is a schematic perspective view that transparently shows the appearance of a magnetic sensor 6A according to a modification. FIG. 20 is a schematic perspective view showing the appearance of the magnetic sensor 7 according to the seventh embodiment of the present invention transparently. FIG. 21 is a schematic perspective view showing the appearance of a magnetic sensor 8 according to the eighth embodiment of the present invention transparently.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First embodiment>
FIG. 1 is a schematic perspective view showing the appearance of a magnetic sensor 1 according to a first embodiment of the present invention in a transparent manner.

  As shown in FIG. 1, the magnetic sensor 1 according to the first embodiment has a configuration in which a plurality of first unit magnetic sensors 10 and a plurality of second unit magnetic sensors 20 are connected in the x direction. The number of connections is arbitrary, and in the example shown in FIG. 1, twelve first unit magnetic sensors 10 and three second unit magnetic sensors 20 are connected in the x direction. In the present embodiment, the width of the first unit magnetic sensor 10 in the x direction is the same as the width of the second unit magnetic sensor 20 in the x direction. As an example, if the width of one unit magnetic sensor 10 or 20 in the x direction is 1 cm, the scan width is 15 cm.

  FIG. 2 is a schematic perspective view showing the appearance of the first unit magnetic sensor 10 transparently, and FIG. 3 is a schematic perspective view showing the external appearance of the second unit magnetic sensor 20 transparently.

  As shown in FIG. 2, the first unit magnetic sensor 10 includes a housing block 10a, a magnetic detection element MR incorporated therein, and a first permanent magnet MG1. The first permanent magnet MG1 is made of, for example, a ferrite magnet, and can be manufactured or obtained at low cost. On the other hand, as shown in FIG. 3, the second unit magnetic sensor 20 includes a housing block 20a, a magnetic detection element MR incorporated therein, and a second permanent magnet MG2. The second permanent magnet MG2 is made of, for example, a neodymium magnet, and is more expensive than a ferrite magnet, but has a stronger magnetic force. The housing blocks 10a and 20a are exterior members made of a non-magnetic material such as a resin, and house a substrate, wiring, and the like on which the magnetic detection element MR and the permanent magnet MG1 or MG2 are mounted. Some of the housing blocks 10a and 20a may be made of metal.

  The housing block 10a has first and second end faces 11 and 12 located on both sides in the x direction, and third and fourth end faces 13 and 14 located on both sides in the z direction. The first and second end faces 11, 12 constitute a yz plane, and the third and fourth end faces 13, 14 constitute an xy plane. Similarly, the housing block 20a has first and second end faces 21 and 22 located on both sides in the x direction, and third and fourth end faces 23 and 24 located on both sides in the z direction. . The first and second end faces 21 and 22 constitute a yz plane, and the third and fourth end faces 23 and 24 constitute an xy plane. Of these, the third end faces 13 and 23 are magnetic head portions facing a member to be measured such as a bill. On the other hand, external terminals (not shown) are led out from the fourth end faces 14 and 24.

  As the magnetic sensing element MR, it is preferable to use a magnetoresistive element whose electric resistance changes in accordance with the direction of a magnetic field. Each of the two magnetoresistive elements is half-bridge connected, or four magnetoresistive elements are used. It is preferable to increase the S / N ratio by connecting the elements in a full bridge. The magnetic detection element MR plays a role of reading a magnetic pattern embedded in the measured member scanned in the x direction (second axis direction) and scanned in the y direction (first axis direction).

  The first permanent magnet MG1 and the second permanent magnet MG2 play a role of applying a bias magnetic field to the magnetic sensing element MR. In this embodiment, since the magnetic sensing element MR and the first or second permanent magnets MG1 and MG2 are arranged so as to overlap in the z direction, a bias magnetic field in the z direction is applied to the magnetic sensing element MR. Will be.

  The bias magnetic field maintains a predetermined stable state in a state where no magnetic pattern exists nearby. If a magnetic pattern exists in the vicinity, the direction of the bias magnetic field changes depending on the magnetic pattern, and the magnetic pattern can be read by the magnetic sensing element MR sensing this. As described above, since the second permanent magnet MG2 has a stronger magnetic force than the first permanent magnet MG1, the second unit magnetic sensor 20 constitutes a highly stable detection and high cost unit magnetic sensor. I do. On the other hand, the first unit magnetic sensor 10 constitutes a low-cost unit magnetic sensor.

  FIG. 4 is a schematic diagram illustrating an example of a bill 40 that is a member to be measured. A bill 40 shown in FIG. 4 has a magnetic pattern 41 with a weak holding force and a magnetic pattern 42 with a strong holding force. The magnetic pattern 42 having a strong coercive force may be called a magnetic thread or a security thread.

  FIG. 5A is a graph showing the magnetic characteristics of the magnetic pattern 41 having a weak coercive force, and FIG. 5B is a graph showing the magnetic characteristics of the magnetic pattern 42 having a strong coercive force.

  As shown in FIG. 5A, in the magnetic pattern 41 having a weak coercive force, the magnetization B when the magnetic field strength H is zero is zero or near it. On the other hand, as shown in FIG. 5B, the magnetic pattern 42 having a strong coercive force has a large magnetization B even when the magnetic field strength H is zero. Therefore, there is a possibility that a past magnetization history remains in the magnetic pattern 42 having a strong coercive force. In order to erase the past magnetization history, it is necessary to refresh by applying a magnetic field of a predetermined value or more.

  In the present embodiment, a plurality (15 in the example shown in FIG. 1) of unit magnetic sensors 10 and 20 are connected in the x direction, and the second unit magnetic sensor 20 using a high-performance magnet at a predetermined position in the x direction. Is arranged. For this reason, if the magnetic pattern 41 having a weak coercive force and the magnetic pattern 42 having a strong coercive force are mixed and the position of the magnetic pattern 42 is known as in the bill 40 shown in FIG. The second unit magnetic sensor 20 may be arranged at the second position. Thus, it is possible to correctly detect both the magnetic pattern 41 having a weak coercive force and the magnetic pattern 42 having a strong coercive force while minimizing the cost increase due to the use of the expensive second unit magnetic sensor 20. Becomes

  As an example, as shown in FIG. 6, when a banknote 40 having a magnetic pattern 42 in the short direction is scanned, the scanning direction (y direction) of the banknote 40 is set to the short direction, and the position in the x direction where the magnetic pattern 42 exists is set. Alternatively, the second unit magnetic sensor 20 may be disposed around the first unit magnetic sensor 20 and the first unit magnetic sensor 10 may be disposed at other positions. Alternatively, as shown in FIG. 7, when scanning a banknote 40 having a magnetic pattern 42 in the longitudinal direction, the scanning direction (y direction) of the banknote 40 is set as the longitudinal direction, and the x-direction position where the magnetic pattern 42 exists or around it. The first unit magnetic sensor 20 may be arranged at the other position, and the first unit magnetic sensor 10 may be arranged at other positions. Thus, the magnetic pattern 42 having a strong holding force can be reliably read, and the entire banknote 40 can be scanned by the first unit magnetic sensor 10.

  As described above, the magnetic sensor 1 according to the present embodiment includes the first unit magnetic sensor 10 that is relatively inexpensive and the second unit magnetic sensor 20 that uses the permanent magnet MG2 that is expensive but has a strong magnetic force. Therefore, it is possible to correctly detect both the magnetic pattern 41 having a weak coercive force and the magnetic pattern 42 having a strong coercive force while minimizing an increase in cost. Further, even if the position of the magnetic pattern 42 having a strong coercive force differs depending on the type of the member to be measured, it is sufficient to simply replace the positions of the unit magnetic sensors 10 and 20. No need to design.

  Further, when some of the unit magnetic sensors 10 and 20 have failed, only the failed unit magnetic sensors 10 and 20 can be replaced with new unit magnetic sensors 10 and 20, thereby improving the maintainability. Moreover, in this embodiment, the first unit magnetic sensor 10 and the second unit magnetic sensor 20 have the same width in the x direction of the first unit magnetic sensor 10 and the second unit magnetic sensor 20. Regardless of the combination, the area scanned by one unit magnetic sensor can be fixed.

  Further, when detecting bills having different sizes and high-definition pattern positions, such as bills from a plurality of countries, the number of connected unit magnetic sensors 10 and 20 and the arrangement thereof are changed according to the bill size and the position of the magnetic thread. Thus, the magnetic sensor 1 having an arbitrary scan width and capable of applying a strong bias magnetic field to an arbitrary position in the x direction can be manufactured, and the design cost can be significantly reduced.

  As a method of connecting the first and second unit magnetic sensors 10 and 20 constituting the magnetic sensor 1, an adhesive is applied to the end faces 11 and 12 of the housing block 10a and the end faces 21 and 22 of the housing block 20a. Alternatively, the first and second unit magnetic sensors 10 and 20 may be provided with engaging portions, and the first or second unit magnetic sensors 10 and 20 adjacent in the x direction may be engaged. Absent.

  FIG. 8 is a schematic perspective view transparently showing the appearance of a first unit magnetic sensor 10A according to a modification, and FIG. 9 is a schematic perspective view transparently showing the appearance of a second unit magnetic sensor 20A according to a modification. is there.

  The first unit magnetic sensor 10A according to the modification shown in FIG. 8 has first and second engaging portions 31 and 32 at substantially the center of the first and second end surfaces 11 and 12 of the housing block 10a. It is different from the first unit magnetic sensor 10 shown in FIG. 2 in that it is provided. Similarly, the second unit magnetic sensor 20A according to the modification shown in FIG. 9 includes a first and a second engagement portion 31 substantially at the center of the first and second end surfaces 21 and 22 of the housing block 20a. , 32 are different from the second unit magnetic sensor 20 shown in FIG. The first engagement portion 31 is a protrusion protruding from the first end surfaces 11 and 21 in the x direction, and has a circular planar shape when viewed from the x direction. On the other hand, the second engagement portion 32 is a concave portion that is depressed in the x direction from the second end surfaces 12, 22, and has a circular planar shape when viewed in the x direction. The diameter of the first engaging portion 31 which is a convex portion is designed to be substantially the same as or slightly smaller than the diameter of the second engaging portion 32 which is a concave portion, and the first engaging portion 31 which is a convex portion. The height of 31 is designed to be substantially the same as or slightly smaller than the depth of the second engaging portion 32 which is a concave portion. That is, the shape of the first engaging portion 31 has a shape that can be engaged with the shape of the second engaging portion 32.

  FIG. 10 is a schematic perspective view showing the appearance of a magnetic sensor 1A in which a plurality of unit magnetic sensors 10A and 20A are connected in the x direction.

  As shown in FIG. 10, unit magnetic sensors 10A and 20A have first and second engaging portions 31 and 32 respectively on first end faces 11 and 21 and second end faces 12 and 22 located on opposite sides. Is provided, the plurality of unit magnetic sensors 10A and 20A can be connected in the x direction. That is, of the two unit magnetic sensors 10A and 20A adjacent in the x direction, the first engaging portion 31 provided on one of the unit magnetic sensors 10A and 20A is provided on the other unit magnetic sensor 10A and 20A. Both can be connected by inserting into the 2nd engaging part 32. This makes it possible to connect the plurality of unit magnetic sensors 10A and 20A in the x direction without using an adhesive or the like.

  In addition, since the planar shapes of the first engaging portion 31 that is the convex portion and the second engaging portion 32 that is the concave portion are all circular, the engaging portions 31 and 32 are less likely to crack or chip. In both cases, the design of a mold for manufacturing the housing blocks 10a and 20a is also facilitated. However, it is not essential that the planar shape of the engaging portions 31 and 32 is circular, and the planar shape of the engaging portions 31 and 32 may be rectangular or elliptical. Further, the number of the engaging portions 31 and 32 does not need to be one, and may be plural. According to these, it is possible to correctly position two unit magnetic sensors adjacent to each other in the x direction without causing a rotational displacement.

<Second embodiment>
FIG. 11 is a schematic perspective view showing the appearance of the magnetic sensor 2 according to the second embodiment of the present invention in a transparent manner.

  As shown in FIG. 11, the magnetic sensor 2 according to the second embodiment includes a dummy housing block D1 having a width in the x direction equal to that of the first and second unit magnetic sensors 10 and 20. This is different from the magnetic sensor 1 according to the first embodiment.

  Depending on the type of the member to be measured such as a bill, the position of the magnetic pattern is known, and it may be known that the magnetic pattern does not exist at a predetermined position. In such a case, like the magnetic sensor 2 according to the present embodiment, the unit magnetic sensor 10 or 20 is arranged at a position where a magnetic pattern exists, and the dummy housing block D1 is placed at a position where no magnetic pattern exists. Can be arranged.

  The dummy housing block D1 has the same shape and size as the unit magnetic sensors 10 and 20, but does not include the magnetic detection element MR and the permanent magnets MG1 and MG2, and can be made of, for example, the entire resin. . Further, similarly to the modified examples shown in FIGS. 8 and 9, an engagement portion may be provided on the housing blocks 10a and 20a and the dummy housing block D1. Then, as shown in FIG. 11, if one or more dummy housing blocks D <b> 1 are inserted into locations where no detection is required, the manufacturing cost of the magnetic sensor 2 can be reduced.

  In the example shown in FIG. 11, the shape and size of the dummy housing block D1 are the same as those of the unit magnetic sensors 10 and 20, but the width in the x direction is the same as that of the unit magnetic sensor 2A shown in FIG. A dummy housing block D2 longer than 20 may be used. According to this, it is possible to reduce the number of components constituting the magnetic sensor 2A. Although not shown, a dummy housing block having a width in the x direction shorter than the unit magnetic sensors 10 and 20 can be used. According to this, the positions of the unit magnetic sensors 10 and 20 in the x direction can be determined. Fine adjustment is possible.

<Third embodiment>
FIG. 13 is a schematic perspective view showing the appearance of the magnetic sensor 3 according to the third embodiment of the present invention transparently.

  As shown in FIG. 13, in the magnetic sensor 3 according to the third embodiment, the housing 50 is shared, and the first permanent magnet MG1 is shared by the plurality of magnetic sensing elements MR. The second embodiment is different from the magnetic sensor 1 according to the first embodiment in that the second permanent magnet MG2 is shared by the magnetic detection element MR.

  Specifically, a common first permanent magnet MG1 is assigned to the five magnetic sensing elements MR located at the left end, and a common first permanent magnet MG1 is assigned to the seven magnetic sensing elements MR located at the right end. A permanent magnet MG1 is allocated, and a common second permanent magnet MG2 is allocated to three magnetic sensing elements MR located substantially at the center. The plurality of magnetic sensing elements MR and the first and second permanent magnets MG1 and MG2 are housed in a common housing 50.

  As exemplified in the present embodiment, it is not essential to connect a plurality of unit magnetic sensors in the present invention. A common housing 50 is used, and a common permanent magnet MG1 is used for a plurality of magnetic sensing elements MR. It is also possible to assign MG2.

<Fourth embodiment>
FIG. 14 is a schematic perspective view showing the appearance of a magnetic sensor 4 according to a fourth embodiment of the present invention transparently.

  As shown in FIG. 14, the magnetic sensor 4 according to the fourth embodiment is different from the magnetic sensor 3 according to the third embodiment in that dummy sensor blocks D1 and D2 are included. Accordingly, the casing 50 is divided into three casings 51 to 53.

  As exemplified in the present embodiment, even when the common permanent magnets MG1 and MG2 are assigned to the plurality of magnetic sensing elements MR, the dummy housing block can be used.

<Fifth embodiment>
FIG. 15 is a schematic perspective view showing the appearance of a magnetic sensor 5 according to a fifth embodiment of the present invention transparently.

  As shown in FIG. 15, in the magnetic sensor 5 according to the fifth embodiment, a first unit magnetic sensor 10B is used instead of the first unit magnetic sensor 10 shown in FIG. 1, and a second unit shown in FIG. It differs from the magnetic sensor 1 according to the first embodiment in that a second unit magnetic sensor 20B is used instead of the unit magnetic sensor 20.

  FIG. 16 is a schematic perspective view showing the appearance of the first unit magnetic sensor 10B transparently, and FIG. 17 is a schematic perspective view showing the external appearance of the second unit magnetic sensor 20B transparently.

  As shown in FIG. 16, the first unit magnetic sensor 10B includes two first permanent magnets MG1a and MG1b, and the magnetic detection element MR is moved from the y direction by the two first permanent magnets MG1a and MG1b. It is sandwiched. Other configurations are the same as those of the first unit magnetic sensor 10 shown in FIG. Similarly, as shown in FIG. 17, the second unit magnetic sensor 20B includes two second permanent magnets MG2a and MG2b, and the magnetic detection element MR is controlled by the two second permanent magnets MG2a and MG2b. It is sandwiched from the y direction. Other configurations are the same as those of the second unit magnetic sensor 20 shown in FIG.

  The first permanent magnets MG1a, MG1b are made of, for example, ferrite magnets, like the first permanent magnet MG1. Further, like the second permanent magnet MG2, the second permanent magnets MG2a and MG2b are made of, for example, neodymium magnets and have a stronger magnetic force than the first permanent magnets MG1a and MG1b.

  In the present embodiment, since the magnetic detection element MR is sandwiched in the y direction by the first permanent magnets MG1a, MG1b or the second permanent magnets MG2a, MG2b, the bias magnetic field in the y direction is applied to the magnetic detection element MR. Is applied.

  As exemplified in this embodiment, in the present invention, the positional relationship between the magnetic detection element and the permanent magnet is not particularly limited, and a configuration in which the magnetic detection element is sandwiched between two permanent magnets may be used.

<Sixth embodiment>
FIG. 18 is a schematic perspective view showing the appearance of a magnetic sensor 6 according to a sixth embodiment of the present invention transparently.

  As shown in FIG. 18, the magnetic sensor 6 according to the sixth embodiment includes a dummy housing block D1 having the same width in the x direction as the first and second unit magnetic sensors 10B and 20B. This is different from the magnetic sensor 5 according to the fifth embodiment.

  The dummy housing block D1 is as described with reference to FIG. 11 and has the same shape and size as the unit magnetic sensors 10B and 20B, but includes the magnetic detection element MR and the permanent magnets MG1a, MG1b, MG2a, and MG2b. No block, for example, the whole can be made of resin. If such a dummy housing block D1 is inserted into a portion where the detection is unnecessary, the manufacturing cost of the magnetic sensor 6 can be reduced.

  In the example shown in FIG. 18, the shape and size of the dummy housing block D1 are the same as those of the unit magnetic sensors 10B and 20B. However, like the magnetic sensor 6A shown in FIG. A dummy housing block D2 longer than 20B may be used. According to this, it is possible to reduce the number of components constituting the magnetic sensor 6A. Although not shown, it is also possible to use a dummy housing block whose width in the x direction is shorter than the unit magnetic sensors 10B and 20B. According to this, the positions of the unit magnetic sensors 10B and 20B in the x direction can be determined. Fine adjustment is possible.

<Seventh embodiment>
FIG. 20 is a schematic perspective view showing the appearance of the magnetic sensor 7 according to the seventh embodiment of the present invention transparently.

  As shown in FIG. 20, in the magnetic sensor 7 according to the seventh embodiment, the housing 50 is shared, and the first permanent magnet MG1 is shared by the plurality of magnetic sensing elements MR. The magnetic sensor 5 according to the fifth embodiment is different from the magnetic sensor 5 according to the fifth embodiment in that the second permanent magnet MG2 is shared by the magnetic sensor MR. That is, it has a configuration similar to that of the magnetic sensor 3 according to the third embodiment shown in FIG. As described above, even in a configuration in which the magnetic detection element is sandwiched between the two permanent magnets, the common casing 50 is used, and the common permanent magnets MG1a, MG1b, MG2a, and MG2b are used for the plurality of magnetic detection elements MR. It is possible to assign.

<Eighth embodiment>
FIG. 21 is a schematic perspective view showing the appearance of a magnetic sensor 8 according to the eighth embodiment of the present invention transparently.

  As shown in FIG. 21, the magnetic sensor 8 according to the eighth embodiment is different from the magnetic sensor 7 according to the seventh embodiment in that dummy sensor blocks D1 and D2 are included. Accordingly, the casing 50 is divided into three casings 51 to 53. As described above, even when the configuration is such that the magnetic detection element is sandwiched between the two permanent magnets, and a common permanent magnet MG1a, MG1b, MG2a, MG2b is assigned to the plurality of magnetic detection elements MR, It is possible to use a dummy housing block.

  As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention. It goes without saying that they are included in the range.

  For example, in each of the above-described embodiments, the arrangement direction (x direction) and the scan direction (y direction) of the unit magnetic sensors are orthogonal to each other. It is sufficient if the scanning directions are different.

  In the above embodiments, two types of unit magnetic sensors having different bias magnetic field intensities are arranged in the x direction. However, three or more types of unit magnetic sensors having different bias magnetic field intensities may be used. .

1, 1A, 2, 2A, 3-6, 6A, 7, 8 Magnetic sensors 10, 10A, 10B First unit magnetic sensors 20, 20A, 20B Second unit magnetic sensors 10a, 20a Housing blocks 11, 21 1st end surface 12,22 2nd end surface 13,23 3rd end surface 14,24 4th end surface 31 1st engaging part 32 2nd engaging part 40 Banknote 41 Magnetic pattern 42 with low holding power Holding Strong magnetic pattern 50 to 53 Cases D1, D2 Dummy case blocks MG1, MG1a, MG1b First permanent magnets MG2, MG2a, MG2b Second permanent magnet MR Magnetic detection element

Claims (10)

A magnetic sensor that reads the magnetic pattern by scanning a member to be measured having a magnetic pattern in a first axis direction,
A plurality of unit magnetic sensors arranged in a second axis direction different from the first axis direction and each having a permanent magnet;
The plurality of unit magnetic sensors include first and second unit magnetic sensors in which the permanent magnets have different magnetic forces from each other. The permanent magnet included in the second unit magnetic sensor has a stronger magnetic force than the permanent magnet included in the first unit magnetic sensor,
The magnetic sensor according to claim 1, wherein the number of the first unit magnetic sensors is larger than the number of the second unit magnetic sensors.   The magnetic sensor according to claim 1, wherein the first and second unit magnetic sensors have the same width in the second axis direction.   The magnetic sensor according to claim 1, wherein the first and second unit magnetic sensors have different widths in the second axis direction.   5. The magnetic sensor according to claim 1, further comprising a dummy housing block arranged in the second axial direction together with the first and second unit magnetic sensors. 6.   The width of the dummy housing block in the second axis direction is the same as the width of at least one of the first and second unit magnetic sensors in the second axis direction. Magnetic sensor.   The magnetic sensor according to claim 5, wherein a width of the dummy housing block in the second axis direction is different from a width of the first and second unit magnetic sensors in the second axis direction. The first and second unit magnetic sensors have a sensor chip having a magnetic detection element,
8. The sensor according to claim 1, wherein the permanent magnet is disposed so as to overlap the sensor chip when viewed from a third axis direction orthogonal to the first axis direction and the second axis direction. The magnetic sensor according to claim 1. The first and second unit magnetic sensors have a sensor chip having a magnetic detection element,
The magnetic sensor according to claim 1, wherein the permanent magnet is disposed so as to sandwich the sensor chip from the first axial direction.   The magnetic sensor according to claim 1, wherein the member to be measured is a bill.

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