JP5534843B2 - Magnetic pattern detector - Google Patents

Description

  The present invention relates to a magnetic pattern detection device that detects a magnetic pattern of a medium such as an object to which a magnetic material is attached or a banknote printed with magnetic ink.

  In a magnetic pattern detection device that detects magnetic patterns from objects such as cards with magnetic materials attached, or paper such as banknotes printed with magnetic ink, the magnetic sensor element detects changes in magnetic flux when the medium passes. The magnetic pattern is detected based on the signal output from the magnetic sensor element. Here, as shown in FIGS. 11A and 11B, the magnetic sensor element is, for example, a channel in the column direction Y (medium width direction) orthogonal to the moving direction X (row direction) of the medium 1. Twenty pieces are arranged for CH1 to CH20, and the magnetic pattern is detected from the entire width direction of the medium 1 by scanning the twenty magnetic sensor elements 40 in the column direction (Patent Document 1). ~ 3).

  That is, if the plurality of magnetic sensor elements 40 shown in FIGS. 11A and 11B are scanned once, data is detected in each of the 20 magnetic sensor elements 40 of the channels CH1 to CH20. As shown in (d), if the magnetic sensor element 40 is converted into a detection data digital signal in the magnetic sensor element 40 by an A / D converter in synchronization with the timing when the magnetic sensor element 40 is in the ON state, the magnetic field for one column of the medium 1 is obtained. A pattern can be detected. Here, the magnetic sensor element 40 is excited by an excitation signal having a frequency of 500 kHz.

  The medium 1 moves in the row direction. For this reason, as shown in FIG. 11C, the area where the magnetic sensor element 40 is located in the on state is shown as a hatched area, and the magnetic sensor element 40 is located in the on state during the current scan in the medium 1. The next magnetic sensor element 40 is in an ON state in a region adjacent to the moving direction X (region with a downward slanting line) on the opposite side to the moving direction X (region with a slanting line to the right) become. Therefore, the magnetic pattern can be detected from the entire medium 1.

JP 2007-241653 A JP 2007-241654 A JP 2009-163336 A

  However, in a magnetic pattern detection apparatus that scans a plurality of magnetic sensor elements 40 arranged in the column direction and moves the medium 1, the moving speed of the medium 1 and the dimensions of the magnetic sensor elements 40 in the moving direction X of the medium 1 Depending on the scan speed, as shown in FIG. 11C, the area where the magnetic sensor element 40 is located in the ON state at the time of the current scan (the area with a diagonal line rising to the right) and the next scan In this case, a gap G is generated between the magnetic sensor element 40 and the region where the magnetic sensor element 40 is located in the ON state (the region with a slanting line to the right). For example, when the moving speed of the medium 1 is 0.0016 mm / μsec and the scan time of the magnetic sensor element in the column direction is 200 μsec, the medium 1 moves 0.32 mm while one scan is completed. When the dimension in the moving direction of the magnetic sensor element 1 is 0.3 mm, the area where the magnetic sensor element 40 is located in the ON state at the time of the current scan and the magnetic sensor element 40 at the time of the next scan. A gap G of 0.02 mm is generated between the region located in the on state. For this reason, in the area corresponding to the gap G in the medium 1, the magnetic characteristics cannot be detected by the magnetic sensor element 40, and it is difficult to accurately detect the magnetic pattern from the entire surface of the medium 1.

  On the other hand, since the magnetic sensor element 40 normally has a sensing range that is equal to or larger than the projection area of the magnetic sensor element 40 with respect to the medium 1, if the gap G can be covered by such a sensing range, a magnetic pattern can be generated from the entire surface of the medium 1. Even in such a case, depending on the moving speed of the medium 1, the size of the sensing range of the magnetic sensor element 40 in the moving direction X of the medium 1, and the scanning speed, It is difficult to avoid the occurrence of the gap G between the sensing range in the next scan.

  In view of the above problems, an object of the present invention is to scan a plurality of magnetic sensor elements arranged in the column direction, and even when a method of moving the medium relative to the magnetic sensor is employed, from the entire surface of the medium. An object of the present invention is to provide a magnetic pattern detection device capable of reliably detecting a magnetic pattern.

In order to solve the above-described problems, the present invention provides a magnetic pattern detection device having a magnetic sensor element that detects magnetic characteristics from a medium, and a transport mechanism that moves the medium relative to the magnetic sensor element. A plurality of the magnetic sensor elements are arranged in a row direction orthogonal to the moving direction of the medium, and the moving speed of the medium by the transport mechanism is v (mm / μsec), and the magnetic sensor element the dimension in the moving direction and T (mm), when the number of scans per unit time t _a (μsec) per value of the magnetic element in the row direction is N times, the moving speed v, the unit time t _a, the dimension T and the number of scans N, the following conditional expression _{(v × t a) ≦ (} T × N)
However, N is characterized by satisfying an integer of 2 or more.

In the present invention, the moving velocity v of the medium, the dimension T in the moving direction of the magnetic sensor element, since the number of scans N per unit time t _a of the magnetic sensor element is set so as to satisfy the above conditional expressions in the row direction A gap does not occur between the region where the magnetic sensor element is located in the on state during the current scan and the region where the magnetic sensor element is located in the on state during the next scan. Therefore, even when a plurality of magnetic sensor elements arranged in the column direction are scanned and the medium is moved relative to the magnetic sensor, the magnetic pattern can be reliably detected from the entire surface of the medium.

In the present invention, the unit time t _a is the one scan period for detecting one row of the magnetic pattern of the medium, data obtained by the magnetic sensor element by the scan was conducted in the one scan period A configuration in which the magnetic pattern for one column of the medium is detected based on the above can be adopted. That is, a plurality of scans are performed during one scan period for detecting a magnetic pattern for one column. For this reason, it is possible to adopt a configuration that detects a magnetic pattern for one column based on data obtained by a plurality of scans, and according to such a configuration, noise or the like is included in any of the data obtained by the magnetic sensor element. Even when the influence is included, the influence of the noise can be reduced.

  In the present invention, a magnetic field corresponding to one column of the medium based on data obtained by the magnetic sensor element by one scan or a plurality of scans out of N scans performed during the one scan period. A configuration in which a pattern is detected can be employed. With this configuration, an optimum operation can be realized according to the type of medium, the detection accuracy required for the magnetic pattern detection device, and the like.

  In the present invention, a magnetic pattern for one column of the medium is detected based on data obtained by the magnetic sensor element by a plurality of scans out of N scans performed during the one scan period. It is preferable. With this configuration, the magnetic characteristics of the medium can be detected with high accuracy. Even if any of the data obtained by the magnetic sensor element includes the influence of noise or the like, the influence of the noise can be mitigated.

  In the present invention, it is possible to adopt a configuration in which a magnetic pattern for one column of the medium is detected based on all data obtained by the magnetic sensor element by N scans performed during the one scan period. . With this configuration, the area where the magnetic sensor element is projected to the medium at the same magnification partially overlaps in the current scan and the next scan, so that the magnetic characteristics of the medium can be detected with high accuracy. . Even if any of the data obtained by the magnetic sensor element includes the influence of noise or the like, the influence of the noise can be mitigated.

  The present invention employs a configuration in which a magnetic pattern for one column of the medium is detected based on data obtained by the magnetic sensor element by a part of N scans performed during one scanning period. May be.

  For example, out of N scans performed during the one scan period, a region in which the magnetic sensor element is projected at the same magnification on the medium partially overlaps in the moving direction in the current scan and the next scan. A plurality of data obtained by the magnetic sensor element by scanning two or more times and less than N times, or an area where the magnetic sensor element is projected at the same magnification on the medium is moved in the current scan and the next scan. A configuration in which a magnetic pattern for one column of the medium is detected based on a plurality of data obtained by the magnetic sensor element by scanning at least twice and less than N times contacting without overlapping in the direction may be adopted. Good.

  In this case, of the N scans performed during the one scan period, an area in which the magnetic sensor element is projected at the same magnification on the medium is partially in the moving direction between the current scan and the next scan. It is preferable that a magnetic pattern for one column of the medium is detected based on a plurality of data obtained by the magnetic sensor element by two or more overlapping scans and less than N scans. With this configuration, the area where the magnetic sensor element is projected to the medium at the same magnification partially overlaps in the current scan and the next scan, so that the magnetic characteristics of the medium can be detected with high accuracy. . Even if any of the data obtained by the magnetic sensor element includes the influence of noise or the like, the influence of the noise can be mitigated.

Further, when the sensing range in the moving direction of the magnetic sensor element is larger than the dimension T in the moving direction of the magnetic sensor element, the sensing range is N out of N scans performed during the one scanning period. A plurality of data obtained by the magnetic sensor element by two or more scans and less than N scans partially overlapping in the moving direction in the current scan and the next scan, or the sensing range is the current scan and the next scan. A configuration in which a magnetic pattern for one column of the medium is detected based on a plurality of data obtained by the magnetic sensor element by scanning at least twice and less than N times in contact with each other without overlapping in the moving direction. May be adopted.

In this case, among the N scans performed during the one scan period, the sensing range is obtained by performing the scan twice or more and less than N times partially overlapping in the moving direction in the current scan and the next scan. It is preferable that a magnetic pattern for one row of the medium is detected based on a plurality of data obtained by the magnetic sensor element. According to this structure, since the cell Nshingu range partially overlap between the current scan and next scan, it is possible to detect the magnetic properties of the medium with high accuracy. Even if any of the data obtained by the magnetic sensor element includes the influence of noise or the like, the influence of the noise can be mitigated.

  In the present invention, when detecting a magnetic pattern for one column of the medium based on a plurality of data obtained by the magnetic sensor element during the one scanning period, an averaging process is performed on the plurality of data. It is preferable. With this configuration, even when a magnetic pattern for one column of the medium is detected from a plurality of data, simple processing is sufficient. In addition, by averaging a plurality of data, even if any of the data obtained by the magnetic sensor element includes the influence of noise or the like, the influence of the noise can be reduced.

  In the present invention, of N scans performed during the one scanning period, which magnetic pattern for one column of the medium is detected based on data obtained by the magnetic sensor element at the time of scanning Is preferably variable. With this configuration, an optimum operation can be realized according to the type of medium, the detection accuracy required for the magnetic pattern detection device, and the like.

  In the present invention, when the magnetic sensor element is excited by an excitation signal and outputs a signal, the excitation signal is added to a signal output by each of the plurality of magnetic sensor elements during a single scan for a plurality of cycles. It is preferable to have a frequency including a signal component by the excitation signal. With this configuration, each signal output from each of the plurality of magnetic sensor elements during one scan includes a signal component due to excitation signals for a plurality of cycles, so that the magnetic characteristics of the medium can be accurately determined. Can be detected.

In the present invention, the moving velocity v of the medium, the dimension in the moving direction of the magnetic sensor element T, the number of scans N the following condition per unit of the magnetic sensor element time t _a in the row direction _{(v × t a) ≦ (} T × N)
However, since N is set so as to satisfy an integer of 2 or more, the area where the magnetic sensor element is located in the on state at the time of the current scan and the magnetic sensor element in the on state at the next scan No gap is generated between the region located at Therefore, even when a plurality of magnetic sensor elements arranged in the column direction are scanned and the medium is moved relative to the magnetic sensor, the magnetic pattern can be reliably detected from the entire surface of the medium.

It is explanatory drawing which shows the structure of the magnetic pattern detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the magnetic sensor apparatus used for the magnetic pattern detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the magnetic sensor element used for the magnetic sensor apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the electrical constitution of the magnetic pattern detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the scanning operation | movement etc. of the magnetic pattern detection apparatus concerning Embodiment 1 of this invention. It is explanatory drawing which shows the operating condition of the circuit part in the magnetic pattern detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the characteristic of the various magnetic inks formed in a medium in the magnetic pattern detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the principle which detects the presence or absence of a magnetic pattern from the medium in which the magnetic pattern from which a kind differs was formed in the magnetic pattern detection apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the position of the magnetic sensor element for every scan in the magnetic pattern detection apparatus concerning Embodiment 2 of this invention. It is explanatory drawing which shows the position of the magnetic sensor element for every scan in the magnetic pattern detection apparatus concerning Embodiment 3 of this invention, and its sensing range. It is explanatory drawing of the conventional magnetic pattern detection apparatus.

  Embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1]
(overall structure)
FIG. 1 is an explanatory diagram showing a configuration of a magnetic pattern detection apparatus according to Embodiment 1 of the present invention, and FIGS. 1A and 1B schematically show a main configuration of the magnetic pattern detection apparatus. It is explanatory drawing and explanatory drawing which shows a cross-sectional structure typically.

  A magnetic pattern detection device 100 shown in FIG. 1 is a device that detects magnetism from a medium 1 such as a banknote or a securities, and performs authenticity determination or type determination. A sheet is detected by a roller or a guide (not shown). And a magnetic sensor device 20 that detects magnetism from the medium 1 at an intermediate position of the medium moving path 11 by the conveying device 10. In this embodiment, the roller and the guide are made of a nonmagnetic material such as aluminum. In this embodiment, the magnetic sensor device 20 is disposed below the medium movement path 11, but may be disposed above the medium movement path 11. In any case, the magnetic sensor device 20 is arranged so that the sensor surface 21 faces the medium moving path 11.

  In this embodiment, the medium 1 is attached to the magnetic region 1a by magnetic ink, and the magnetic pattern is formed by a plurality of types of magnetic inks having different residual magnetic flux density Br and magnetic permeability μ. For example, the medium 1 is formed with a first magnetic pattern printed with magnetic ink containing hard material and a second magnetic pattern printed with magnetic ink containing soft material. Therefore, the magnetic pattern detection apparatus 100 of the present embodiment detects the presence / absence of each magnetic pattern in the medium 1 based on both the residual magnetic flux density level and the magnetic permeability level. In this embodiment, the magnetic sensor device 20 for detecting such two types of magnetic patterns is common. Therefore, the magnetic pattern detection apparatus 100 of this embodiment has the following configuration.

(Configuration of Magnetic Sensor Device 20)
FIG. 2 is an explanatory diagram of the magnetic sensor device 20 used in the magnetic pattern detection device 100 according to the first embodiment of the present invention. FIGS. 2 (a) and 2 (b) are magnetic sensor elements in the magnetic sensor device 20. FIG. 3 is an explanatory diagram showing a layout of a magnetic field application magnet and the like, and an explanatory diagram showing a direction of a magnetic sensor element.

  As shown in FIGS. 1 and 2A, in the magnetic pattern detection device 100 of the present embodiment, the magnetic sensor device 20 includes a magnetic field applying magnet 30 that applies a magnetic field to the medium 1, and a medium after the magnetic field is applied. 1 includes a magnetic sensor element 40 that detects a magnetic flux when a bias magnetic field is applied, and a nonmagnetic case 25 that covers the magnetic field applying magnet 30 and the magnetic sensor element 40. The magnetic sensor device 20 includes a sensor surface 21 that is substantially flush with the medium movement path 11, and slope portions 22 and 23 that are connected to both sides of the sensor surface 21 in the movement direction of the medium 1. The shape is defined by the shape of the case 25.

  The magnetic sensor device 20 extends in the moving direction X of the medium 1 (the direction intersecting the row direction), and a plurality of magnetic field applying magnets 30 and magnetic sensor elements 40 are arranged in the direction intersecting the moving direction X of the medium 1. In this embodiment, the magnetic sensor device 20 extends in the column direction Y (medium width direction) orthogonal to the movement direction X among the directions intersecting the movement direction X of the medium 1, The magnetic field applying magnets 30 and the magnetic sensor elements 40 are arranged in a plurality of rows in the column direction Y orthogonal to the moving direction X, and are arranged at equal intervals in a row, so that the plurality of magnetic sensor elements 40 arranged in the row direction Y are arranged. If the scanning is sequentially turned on, the magnetic pattern in the column direction Y of the medium 1 can be detected, and if the medium 1 is moved in the movement direction X in parallel with the scanning, the entire medium 1 is detected. Detecting the magnetic pattern of The “on state” herein refers to an active state in which an excitation signal described later is applied to the magnetic sensor element 40 and signal processing is performed on a signal output from the magnetic sensor element 40. means.

In the present embodiment, the magnetic field application magnet 30 is arranged as a first magnetic field application magnet 31 and a second magnetic field application magnet 32 on both sides in the moving direction of the medium 1 with respect to the magnetic sensor element 40, and is indicated by an arrow X1. A magnetic field applying first magnet 31, a magnetic sensor element 40, and a magnetic field applying second magnet 32 are arranged in this order along the moving direction of the medium 1 shown. A magnetic field application second magnet 32, a magnetic sensor element 40, and a magnetic field application first magnet 31 are arranged in this order along the moving direction of the medium 1 indicated by the arrow X2, and the medium 1 is indicated by the arrow X1. The magnetic property of the medium 1 can be detected regardless of the direction and the direction indicated by the arrow X2. Here, the magnetic sensor element 40 is disposed at an intermediate position between the first magnet 31 and second magnet 32 for magnetic field application for field application, apart from the first magnet 31 and the magnetic sensor element 40 for field application The distance is equal to the separation distance between the magnetic field application second magnet 32 and the magnetic sensor element 40. The first magnetic field application magnet 31, the magnetic sensor element 40, and the second magnetic field application magnet 32 are all arranged so as to face the sensor surface 21 of the magnetic sensor device 20.

  In this embodiment, the magnetic field application magnet 30 (the first magnetic field application magnet 31 and the second magnetic field application magnet 32) includes a permanent magnet 35 such as a ferrite or neodymium magnet. In both the first magnetic field application magnet 31 and the second magnetic field application magnet 32, the permanent magnet 35 has a pole on which the side located on the sensor surface 21 is different from the side opposite to the side on which the sensor surface 21 is located. Magnetized. For this reason, in the permanent magnet 35, a surface located on the sensor surface 21 side functions as a magnetized surface 350 for the medium 1. That is, in the magnetic pattern detection device 100 of the present embodiment, as described later, when the moving medium 1 as indicated by the arrow X1 passes through the magnetic sensor device 20, first, the magnetic field applying first magnet 31 is changed to the medium 1. The medium 1 after being magnetized by the magnetic field passes through the magnetic sensor element 40. Further, when the moving medium 1 passes through the magnetic sensor device 20 as shown by the arrow X2, first, a magnetic field is applied to the medium 1 from the second magnetic field application magnet 32, and the medium is magnetized by the magnetic field. 1 passes through the magnetic sensor element 40.

  The plurality of permanent magnets 35 used for the magnetic field applying magnet 30 are all the same in size and shape, but are arranged in the following orientations. First, in both the first magnetic field application magnet 31 and the second magnetic field application magnet 32, the permanent magnets 35 adjacent in the column direction Y orthogonal to the moving direction X of the medium 1 are magnetized in opposite directions. Has been. That is, among the plurality of permanent magnets 35 arranged in the column direction Y orthogonal to the moving direction X of the medium 1, one permanent magnet 35 is magnetized with an N pole at an end located on the medium moving path 11 side. The end located on the side opposite to the medium moving path 11 side is magnetized to the S pole, but is adjacent to the permanent magnet 35 in the column direction Y perpendicular to the moving direction X of the medium 1. 35, the end located on the medium moving path 11 side is magnetized to the S pole, and the end located on the opposite side to the medium moving path 11 side is magnetized to the N pole. In this embodiment, the permanent magnet 35 of the first magnetic field application magnet 31 and the permanent magnet 35 of the second magnetic field application magnet 32 that face each other in the moving direction of the medium 1 have different poles across the magnetic sensor element 40. Opposite. However, the permanent magnet 35 of the first magnetic field application magnet 31 and the permanent magnet 35 of the second magnetic field application magnet 32 that face each other in the moving direction of the medium 1 are arranged so that the same poles face each other across the magnetic sensor element 40. Sometimes placed.

(Configuration of the magnetic sensor element 40)
3 is an explanatory diagram of the magnetic sensor element 40 used in the magnetic sensor device 20 according to the first embodiment of the present invention. FIGS. 3 (a), 3 (b), and 3 (c) show the magnetic sensor element 40. FIG. 4 is a front view, an explanatory diagram of an excitation waveform for the magnetic sensor element 40, and an explanatory diagram of an output signal from the magnetic sensor element 40. FIG. 3A shows a state where the medium 1 moves in a direction perpendicular to the drawing.

  As shown in FIG. 1B, each of the magnetic sensor elements 40 has a thin plate shape, and the size in the width direction W40 is larger than the size in the thickness direction T40. The magnetic sensor element 40 is arranged with the thickness direction T40 facing the moving direction X of the medium 1, and the width direction W40 faces the column direction Y orthogonal to the moving direction X of the medium 1.

  The magnetic sensor element 40 is covered with thin plate-like nonmagnetic members 47 whose both surfaces are made of ceramic or the like, and the entire thickness direction of the magnetic sensor element 40 including the nonmagnetic member 47 is the thickness dimension of the magnetic sensor element 40. (Dimension T described later). The magnetic sensor element 40 may be housed in a magnetic shield case (not shown). In this case, the magnetic shield case is opened at the top where the medium movement path is located, and the magnetic sensor element 40 is exposed from the magnetic shield case toward the medium movement path 11.

  As shown in FIGS. 1B, 2A, 2B, and 3A, the magnetic sensor element 40 includes a sensor core 41, an excitation coil 48 wound around the sensor core 41, and a sensor core. And a detection coil 49 wound around 41. In the present embodiment, the sensor core 41 includes a body part 42 extending in the width direction W40 of the magnetic sensor element 40, and a magnetic flux collecting protrusion 43 that protrudes from the body part 42 toward the medium moving path 11 side of the medium 1. It has. Here, the magnetic flux collecting projections 43 are configured as two magnetic flux collecting projections 431 and 432 protruding from both ends of the body portion 42 in the width direction W40 toward the medium moving path 11 side of the medium 1. The two magnetic flux collecting projections 431 and 432 are separated in the width direction W40. In addition, the sensor core 41 includes a protrusion 44 that protrudes from the body 42 to the side opposite to the magnetism-collecting protrusion 43. In this embodiment, the protrusion 44 has both end portions in the width direction W40 of the body 42. Are formed as two protrusions 441 and 442 protruding toward the opposite side of the medium 1 from the medium moving path 11 side.

  With respect to the sensor core 41 configured as described above, the exciting coil 48 is wound around a portion sandwiched between the magnetic flux collecting projections 431 and 432 in the body portion 42. Further, the detection coil 49 is wound around the magnetic flux collecting projection 43, and in this embodiment, the detection coil 49 includes two magnetic flux collecting projections 43 (the magnetic flux collecting projections 431 and 432) of the sensor core 41. Among them, a detection coil 491 wound around the magnetic flux collection protrusion 431 and a detection coil 492 wound around the magnetic flux collection protrusion 432 are included. Here, the two detection coils 491 and 492 are wound around the magnetic flux collecting projections 431 and 432 in opposite directions. Further, since the two detection coils 491 and 492 are formed by continuously winding one coil wire around the magnetic flux collecting projections 431 and 432, the two detection coils 491 and 492 are electrically connected in series. It is connected to the. The two detection coils 491 and 492 may be wound around the magnetic flux collecting projections 431 and 432, respectively, and then electrically connected in series.

  In the magnetic sensor element 40 configured as described above, the thickness direction T40 perpendicular to both the width direction W40 and the projecting direction (height direction V40) of the magnetic flux collecting projection 43 is directed to the moving direction X of the medium 1. In the magnetic sensor element 40, the width direction W40 in which the magnetic flux collecting protrusions 43 (magnetic flux collecting protrusions 431 and 432) and the detection coils 49 (detection coils 491 and 492) are separated from each other is It faces the column direction Y orthogonal to the movement direction X.

  In the magnetic sensor element 40, an excitation signal composed of an alternating current (see FIG. 3B) is applied to the excitation coil 48 from an excitation circuit 50 described later with reference to FIG. For this reason, as shown in FIG. 3A, a bias magnetic field is formed around the sensor core 41, and a detection waveform signal shown in FIG. become. Here, the detected waveform shown in FIG. 3C is a temporal differential signal of the magnetic flux generated by the excitation signal, and is close to the temporal differential signal of the excitation signal.

  In this embodiment, the sensor core 41 of the magnetic sensor element 40 has a magnetic material layer 41c sandwiched between a nonmagnetic first substrate 41a and a nonmagnetic second substrate 41b, as shown in FIG. 1B. It has a structure. In this embodiment, the magnetic material layer 41c is made of a thin plate-like amorphous metal foil made of an amorphous (amorphous) metal magnetic material bonded to one surface of the first substrate 41a by an adhesive layer (not shown). The second substrate 41b is bonded to one surface of the first substrate 41a by an adhesive layer so as to sandwich the magnetic material layer 41c therebetween. Each of these adhesive layers is a layer formed by solidifying a prepreg formed by impregnating a resin material into a fiber reinforcing material such as glass cloth, carbon fiber, or aramid fiber. As the resin material, an epoxy resin type or a phenol resin type is used. A thermosetting resin such as polyester resin is used. The amorphous metal foil used as the magnetic material layer 41c is formed by rolling with a roll, and examples of cobalt-based materials include Co—Fe—Ni—Mo—B—Si, Co—Fe—Ni—B—Si, and the like. Amorphous alloys, such as Fe-B-Si, Fe-B-Si-C, Fe-B-Si-Cr, Fe-Co-B-Si, Fe-Ni-Mo-B, etc. Can be illustrated. Examples of the first substrate 41a and the second substrate 41b include ceramic substrates such as alumina substrates, glass substrates, and the like, and plastic substrates may be used as long as sufficient rigidity can be obtained.

(Configuration of the signal processing unit 60)
FIG. 4 is an explanatory diagram showing the electrical configuration of the magnetic pattern detection device 100 according to the first embodiment of the present invention, and FIGS. 4A and 4B show the overall configuration of the main part of the circuit unit. It is explanatory drawing and an explanatory view showing signs that a plurality of magnetic sensor elements are scanned and sequentially turned on.

  In this embodiment, the circuit unit 5 shown in FIG. 4A is generally configured by an excitation circuit 50 that applies an alternating current shown in FIG. 3B to the excitation coil 48 as an excitation signal, and a detection coil 49 of the magnetic sensor element 40. (See FIG. 2B and FIG. 3A) and a signal processing unit 60 that is electrically connected. The excitation circuit 50 includes a plurality of excitation driver amplifiers 51 corresponding to each of the plurality of magnetic sensor elements 40 shown in FIG. 2, and a multiplexer 52 for sequentially supplying excitation signals to the plurality of excitation driver amplifiers 51. And an amplifier 53 for generating an excitation signal from the excitation command signal. The excitation coil 48 (see FIGS. 2B and 3A) of the plurality of magnetic sensor elements 40 includes an excitation driver amplifier 51. The excitation signals after being amplified in step 1 are sequentially supplied. Note that a common excitation driver amplifier 51 may be arranged for the plurality of magnetic sensor elements 40 at the subsequent stage of the multiplexer 52.

  The signal processing unit 60 generates a first signal S1 corresponding to the residual magnetic flux density level and a second signal S2 corresponding to the magnetic permeability level from the sensor output signal output from the detection coil 49 of the magnetic sensor device 20. The data is output to an upper control unit (not shown).

  More specifically, the signal processing unit 60 includes an amplification unit 70 including an amplifier 71 that amplifies the sensor output signal output from the magnetic sensor element 40, and a peak value and a bottom value from the signal output from the amplification unit 70. And a digital signal processing unit 90 provided with an A / D converter 91. The extraction unit 80 includes a multiplexer 81 that sequentially outputs the amplified signal output from the amplification unit 70 to the subsequent stage, a clamp circuit 82, and an offset adjustment circuit 83 that performs offset adjustment of the signal output from the clamp circuit 82. ing. The clamp circuit 82 includes a first diode 821 that rectifies the amplified sensor output signal output from the amplification unit 70, and a polarity inversion circuit 822 that performs polarity inversion of the amplified sensor output signal output from the amplification unit 70. And a second diode 823 that rectifies the signal whose polarity is inverted in the polarity inverting circuit 822. Accordingly, the offset adjustment circuit 83 includes a first offset adjustment circuit 831 for the output from the first diode 821 and a second offset adjustment circuit 832 for the output from the second diode 823, and the first offset adjustment circuit 831. The second offset adjustment circuit 832 includes offset adjustment reference voltage generation circuits 831a and 832a and operational amplifiers 831b and 832b. A common amplifier 71 may be arranged for the plurality of magnetic sensor elements 40 at the subsequent stage of the multiplexer 81.

The extraction unit 80 includes a hold circuit 84 following the offset adjustment circuit 83 and a gain setting unit 85 subsequent to the hold circuit 84. The hold circuit 84 includes a first peak hold circuit 841 that holds the peak value of the output signal from the first offset adjustment circuit 831, and a second peak hold circuit that holds the peak value of the output signal from the second offset adjustment circuit 832. 842. Here, the second offset adjustment circuit 832 receives a signal obtained by inverting the polarity of the signal output from the amplification unit 70 by the polarity inverting circuit 822 and then rectifying the signal by the second diode 823. For this reason, the second peak hold circuit 842 corresponds to a bottom hold circuit that holds the bottom value of the amplified signal output from the amplification unit 70.

  The gain setting unit 85 sets the gain of the value held by the first peak hold circuit 841 and the gain of the value held by the second peak hold circuit 842 (bottom hold circuit). The gain setting second amplifier 852 is set, and the values held by the first peak hold circuit 841 and the second peak hold circuit 842 are set to a predetermined gain, and the A / D of the digital signal processing unit 90 is set. Output to the converter 91.

  The digital signal processor 90 adds the value held by the A / D converter 91, the first peak hold circuit 841, and the value held by the second peak hold circuit 842 to generate the first signal S1. The addition circuit 92 includes a subtraction circuit 93 that subtracts the value held by the first peak hold circuit 841 and the value held by the second peak hold circuit 842 to generate the second signal S2.

  Here, as will be described later, the magnetic sensor element 40 outputs a plurality of signals (four signals in this embodiment) during one scanning period to determine the magnetic characteristics of one region on the medium 1. Therefore, the digital signal processing unit 90 includes an averaging processing unit 96 subsequent to the A / D converter 91. Therefore, the adder circuit 92 digitally signals the four values held by the first peak hold circuit 841 and the second peak hold circuit 842 by the A / D converter 91, and then the four values are averaged by the averaging processor 96. Addition processing is performed using the averaged values. The subtracting circuit 93 digitalizes the four values held by the first peak hold circuit 841 and the second peak hold circuit 842 by the A / D converter 91 and then averages the four values by the averaging processing unit 96. Subtraction processing is performed using the converted value.

  The digital signal processing unit 90 includes a control signal output unit 94 that outputs a switching control signal, an excitation command signal, an offset control signal, and the like. The switching control signal controls the multiplexers 52 and 81, and FIG. As shown in FIGS. 3A and 3B, the scanning operation of the magnetic sensor elements 40 arranged in the column direction Y and the timing at which other circuits operate are controlled.

  The digital signal processing unit 90 configured in this manner outputs a first signal S1 and a second signal S2 to a higher-level control unit (not shown). In the control unit, the first signal S1 and the second signal S2 are output. The authenticity of the medium 1 is determined based on the two signals S2. More specifically, the upper control unit associates the first signal S1 and the second signal S2 with the relative position information between the magnetic sensor element 40 and the medium 1, and the comparison pattern recorded in advance in the recording unit. And a determination unit that determines whether the medium 1 is true or false. The determination unit is a predetermined unit based on a program recorded in advance in a recording unit (not shown) such as a ROM or a RAM. Processing is performed to determine whether the medium 1 is true or false.

(Scanning operation of the magnetic sensor element 40)
FIG. 5 is an explanatory diagram showing the scanning operation and the like of the magnetic pattern detection apparatus 100 according to the first embodiment of the present invention. FIGS. 5 (a), (b), (c), and (d) are in the column direction. FIG. 2 is an explanatory diagram showing a state in which the magnetic sensor elements 40 are arranged in Y, an explanatory diagram showing an enlarged layout of the magnetic sensor elements, and a location where the magnetic sensor elements in the ON state are located for each scan during one scanning period. FIG. 3 is an explanatory diagram showing a state in which the magnetic sensor element moves on the medium 1 and an explanatory diagram further enlarging a state in which the position where the magnetic sensor element in the on state moves for each scan during the one scanning period. . FIGS. 6A and 6B are explanatory diagrams showing the operating conditions of the circuit unit in the magnetic pattern detection apparatus 100 according to the first embodiment of the present invention. FIGS. 6A and 6B show the frequency of the detection signal, the sample hold operation, FIG. 5 is an explanatory diagram illustrating the relationship between the A / D converter 91 and the frequency characteristics of the averaging processing unit 96 illustrated in FIG. 4A.

  As shown in FIGS. 5A and 5B, in the magnetic pattern detection device 100 of the present embodiment, the magnetic sensor element 40 is in the column direction Y (medium width direction) orthogonal to the moving direction X of the medium 1. Twenty channels are arranged for the channels CH1 to CH20, and the magnetic pattern is detected from the entire width direction of the medium 1 by scanning the 20 magnetic sensor elements 40 in the column direction. That is, if a plurality of magnetic sensor elements 40 are scanned in the column direction, data is detected in each of the 20 magnetic sensor elements 40 of the channels CH1 to CH20. Further, the medium 1 moves in the row direction (movement direction X). For this reason, a magnetic pattern can be detected from the entire medium 1.

In the magnetic pattern detection apparatus 100 configured as described above, in this embodiment, the moving speed of the medium 1 by the transport mechanism 10 is v (mm / μsec), and the dimension of the magnetic sensor element 40 in the moving direction X is T (mm). When the number of scans per unit time t _a (μsec) of the magnetic sensor element 40 in the column direction Y is N times, the moving speed v, the unit time t _a , the dimension T, and the number of scans N are as follows: _{v × t a) ≦ (T} × N)
However, N satisfies an integer of 2 or more. Here, the unit time t _a is the one scan period for detecting one row of the magnetic pattern of the medium 1. Therefore, in this embodiment, the magnetic sensor element 40 is scanned N times in the column direction Y during one scanning period, and one column is based on all data obtained by the magnetic sensor element 40 by the N times of scanning. Minute magnetic pattern is detected.

More specifically, in the magnetic pattern detection apparatus 100 of the present embodiment, the moving speed v, the unit time t _a , the dimension T, the number of scans N, and the like are, for example, the following conditions: Medium moving speed v = 0.016 mm / μsec
Unit time t _a (one scanning period) = 200 μsec (5 kHz)
The dimension T (thickness dimension) of the magnetic sensor element 40 in the moving direction X of the medium 1 = 0.3 mm.
Number of scans N = 4 in unit time t _a (one scan period)
Is set to Therefore, the moving distance of the medium 1 during one scanning period is as follows: The moving distance of the medium 1 during one scanning period = 0.32 mm
Movement distance of medium 1 during one scan = 0.08 mm
Time per scan = 50 μsec (20 kHz)
On-time of the magnetic sensor element 40 in one scan = 2.5 μsec
It becomes. With such conditions, the following settings (v × t _a) = 0.32mm
(T × N) = 1.2mm
Since, the following condition _{(v × t a) ≦ (} T × N)
However, N sufficiently satisfies an integer of 2 or more.

  Therefore, when the magnetic sensor element 40 is scanned in the column direction under the above conditions, the medium 1 moves 0.08 mm while one scan is completed, but the dimension of the magnetic sensor element 1 in the moving direction is 0.3 mm. is there. For this reason, the area in which the magnetic sensor element 40 is projected onto the medium 1 at the same magnification partially overlaps in the movement direction X between the current scan and the next scan.

  More specifically, as shown in FIGS. 5 (c) and 5 (d). 5C and 5D show an area where the magnetic sensor element 40 for the channel CH1 is in the ON state during the first scan in the n-th scanning period (the ON state with respect to the medium 1). A region obtained by projecting the magnetic sensor element 40 for the channel CH1 at the same magnification) is indicated by a solid line SCH (n, 1). Further, a region in which the magnetic sensor element 40 for the channel CH1 is located in the ON state during the second scan in the current scanning period (n-th) is indicated by an alternate long and short dash line SCH (n, 2). Further, a region where the magnetic sensor element 40 for the channel CH1 is located in the ON state during the third scan in the current scanning period (n-th) is indicated by a dotted line SCH (n, 3). A region where the magnetic sensor element 40 for the channel CH1 is located in the ON state during the fourth scan in the current scanning period (n-th) is indicated by a two-dot chain line SCH (n, 4). In each scan, the area where the magnetic sensor element 40 is in the on state moves in the same direction in the column direction Y. In FIGS. 5C and 5D, the position of each area is shown. It is slightly shifted in the column direction Y for easy understanding. 5 (c) and 5 (d) show the magnetic sensor element for channel CH1 during the (n + 1) th scanning period as a region where the magnetic sensor element 40 is positioned in the ON state during the (n + 1) th scanning period. Only the area 40 is located at the time of the first scan is shown.

  In the present embodiment, since the above conditional expression is satisfied, in one scanning period, the region where the magnetic sensor element 40 is located during the first scan and the magnetic sensor during the second scan. A region where the element 40 is located partially overlaps in the movement direction X. The same is true between the second scan and the third scan, and between the third scan and the fourth scan. The region in which the magnetic sensor element 40 is located in the next scan partially overlaps in the movement direction X. Accordingly, in the current scan and the next scan, the area where the magnetic sensor element 40 is turned on at the current scan is projected onto the medium 1 at the same magnification, and the magnetic sensor element 40 is turned on at the next scan. There is no gap between the position projected onto the medium 1 and the same magnification. The same applies to the magnetic sensor elements 40 for other channels.

  In addition, the region SCH1 (n) obtained by adding up the regions where the magnetic sensor element 40 for the channel CH1 is in the ON state during the first to fourth scans in the current scanning period (n-th) is indicated by a solid line SCH. It is a region obtained by adding up the region indicated by (n, 1), the region indicated by the one-dot chain line SCH (n, 2), the region indicated by the dotted line SCH (n, 3), and the region indicated by the two-dot chain line SCH (n, 2). The region SCH1 (n) is a region (solid line CH1 (n + 1, 1) indicated by the solid sensor CH1 (n + 1, 1) where the magnetic sensor element 40 is in the on state during the first scan in the next scan period (n + 1th scan period). ) And partially overlap in the direction of movement. Therefore, the area where the magnetic sensor element 40 was turned on when it was last scanned in the current scanning period is projected onto the medium 1 at the same magnification, and the magnetic sensor element 40 is first scanned during the next scanning period. There is no gap between the turned-on position and the area projected on the medium 1 at the same magnification. The same applies to the magnetic sensor elements 40 for other channels.

  Such a scan operation is represented as shown in FIG. 4B, and a scan in which the magnetic sensor elements 40 of the channels CH1 to CH20 are sequentially turned on is executed a total of four times during one scan period. In conjunction with this operation, the A / D converter 91 shown in FIG. 4A matches the timing at which each magnetic sensor element 40 is turned on at a sampling period of 50 μsec (sampling frequency = 20 kHz). Is converted into a digital signal for each channel.

  Here, in this embodiment, the frequency of the excitation signal shown in FIG. 3B is set to 2 MHz because the on-time of the magnetic sensor element 40 for each CH is reduced to 2.5 μsec. Therefore, as shown in FIG. 6A, the magnetic sensor element 40 has a plurality of signal components (sensor output signals) shown in FIG. 3C during one ON time (2.5 μsec). 3 in the form) and is output to the extraction unit 80 shown in FIG. That is, the excitation signal has a frequency at which the signal component of the excitation signal for a plurality of cycles is included in the signal output from each of the plurality of magnetic sensor elements 40 during one scan. A plurality of signal components are included in each detection signal output from each of the plurality of magnetic sensor elements 40 during scanning. Therefore, even if the ON time of the magnetic sensor element 40 is short, the first peak hold circuit 841 and the second peak hold circuit 842 can hold three times in the hold circuit 84 shown in FIG. Therefore, peak hold can be performed reliably.

  Further, in the present embodiment, the necessary band of the signal input to the A / D converter 91 shown in FIG. 4A is a relatively low frequency band, and therefore, a solid line is shown in FIG. 6B. As described above, the sampling frequency of the A / D converter 91 is set to 20 kHz for each CH, and is set to a relatively low frequency. For this reason, the signal output from the magnetic sensor element 40 can be appropriately converted into a digital signal. That is, with the configuration described with reference to FIG. 11, the sampling frequency of the A / D converter 91 is set to 1 MHz as shown as a reference example in FIG. Even if the sampling is performed four times in the middle (the flat portion of the signal after the hold in FIG. 6A) and the average processing is performed, there is a problem that the effect of reducing the noise of the frequency component higher than the signal band (5 kHz) is small. However, in this embodiment, since the sampling frequency of the A / D converter 91 is set to 20 kHz, it is possible to reduce noise having a frequency component higher than 5 kHz even if the same averaging process is performed four times.

(Detection principle)
FIG. 7 is an explanatory diagram showing characteristics and the like of various magnetic inks formed on the medium 1 in the magnetic pattern detection apparatus 100 according to Embodiment 1 of the present invention. FIG. 8 is an explanatory diagram showing the principle of detecting the presence / absence of a magnetic pattern from the medium 1 on which different types of magnetic patterns are formed in the magnetic pattern detection apparatus 100 according to Embodiment 1 of the present invention.

  First, the principle of determining the authenticity of the medium 1 when the medium 1 moves in the direction of the arrow X1 shown in FIGS. 1 and 2 will be described. In this embodiment, a plurality of types of magnetic patterns having different residual magnetic flux density Br and magnetic permeability μ are formed in the magnetic region 1 a of the medium 1. More specifically, the medium 1 is formed with a first magnetic pattern printed with a magnetic ink containing a hard material and a second magnetic pattern printed with a magnetic ink containing a soft material. Here, the magnetic ink containing the hard material has a high level of residual magnetic flux density Br when a magnetic field is applied, as shown in FIG. 7B1 by the hysteresis loop, such as residual magnetic flux density Br and permeability μ. The permeability μ is low. On the other hand, as shown in FIG. 7C1, the magnetic ink containing the soft material has a low residual magnetic flux density Br when the magnetic field is applied, but has a high permeability μ.

  Therefore, as will be described below, the material of the magnetic ink can be determined by measuring the residual magnetic flux density Br and the magnetic permeability μ. More specifically, since the magnetic permeability μ has a correlation with the holding force Hc, in this embodiment, the residual magnetic flux density Br and the holding force Hc are measured, and the residual magnetic flux density Br is measured. And the holding force Hc differ depending on the magnetic ink (magnetic material). Therefore, the material of the magnetic ink can be determined. Further, the measured values of the residual magnetic flux density Br and the magnetic permeability μ (holding force Hc) vary depending on the density of the ink and the distance between the medium 1 and the magnetic sensor device 20, but in this embodiment, the magnetic sensor device 20 is the same. Since the residual magnetic flux density Br and the magnetic permeability μ (holding force Hc) are measured at the position, the material of the magnetic ink can be reliably determined according to the ratio of the residual magnetic flux density Br and the holding force Hc.

  In the magnetic pattern detection apparatus 100 of the present embodiment, when the medium 1 moves in the direction indicated by the arrow X1 and passes through the magnetic sensor apparatus 20, first, a magnetic field is applied from the first magnetic field application magnet 31 to the medium 1, and the magnetic field The medium 1 after is applied passes through the magnetic sensor element 40. Until then, the detection coil 49 of the magnetic sensor element 40 outputs a signal corresponding to the BH curve of the sensor core 41 shown in FIG. 7 (a2), as shown in FIG. 7 (a3). Accordingly, the first signal S1 output from the adder circuit 92 shown in FIG. 4 and the second signal S2 output from the subtractor circuit 93 are as shown in FIG. 7 (a4).

  Here, when the first magnetic pattern is formed on the medium 1 with the magnetic ink containing a hard material such as ferrite powder, the first magnetic pattern has a high level as shown in FIG. 7 (b1). It has a residual magnetic flux density Br. Therefore, as shown in FIG. 8A1, when the medium 1 passes through the magnetic field application magnet 30, the first magnetic pattern becomes a magnet by the magnetic field from the magnetic field application magnet 30. For this reason, the signal output from the detection coil 49 of the magnetic sensor element 40 receives a DC bias from the first magnetic pattern as shown in FIG. 7 (b2), and FIG. 7 (b3) and FIG. The waveform changes to (a2). That is, the peak voltage and the bottom voltage of the signal S0 are shifted in the same direction as indicated by arrows A1 and A2, and the shift amount of the peak voltage and the shift amount of the bottom voltage are different. Moreover, the signal S0 changes as the medium 1 moves. Therefore, the first signal S1 output from the adder circuit 92 shown in FIG. 4 is as shown in FIG. 7B4, and fluctuates every time the first magnetic pattern of the medium 1 passes through the magnetic sensor element 40. . Here, since the magnetic permeability μ is low in the first magnetic pattern formed by the magnetic ink containing the hard material, the first magnetic pattern has an influence on the shift of the peak voltage and the bottom voltage of the signal S0. It can be considered that only the residual magnetic flux density Br. Therefore, the second signal S2 output from the subtraction circuit 93 shown in FIG. 4 does not fluctuate even if the first magnetic pattern of the medium 1 passes through the magnetic sensor element 40, and the signal shown in FIG. 7 (b4). It is the same.

  On the other hand, when the second magnetic pattern is formed on the medium 1 with magnetic ink containing a soft material such as soft magnetic stainless steel powder, the hysteresis loop of the second magnetic pattern is shown in FIG. As shown, the level of the residual magnetic flux density Br is low through the inside of the hysteresis curve of the first magnetic pattern by the magnetic ink containing the hard material shown in FIG. 7 (b1). For this reason, even after the medium 1 passes through the magnetic field applying magnet 30, the second magnetic pattern has a low residual magnetic flux density Br. However, since the magnetic permeability μ is high, the second magnetic pattern functions as a magnetic material as shown in FIG. Therefore, as shown in FIG. 8C2, the signal output from the detection coil 49 of the magnetic sensor element 40 has a higher magnetic permeability μ due to the presence of the second magnetic pattern. ) And the waveform shown in FIG. 8 (b2). That is, the peak voltage of the signal S0 is shifted to the higher side as indicated by the arrow A3, while the bottom voltage is shifted to the lower side as indicated by the arrow A4. At that time, the absolute value of the shift amount of the peak voltage and the shift amount of the bottom voltage are substantially equal. Moreover, the signal S0 changes as the medium 1 moves. Therefore, the second signal S2 output from the subtraction circuit 93 shown in FIG. 4 is as shown in FIG. 8C4, and fluctuates every time the second magnetic pattern of the medium 1 passes through the magnetic sensor element 40. . Here, since the second magnetic pattern formed by the magnetic ink containing the soft material has a low residual magnetic flux density Br, it is the second magnetic pattern that affects the shift of the peak voltage and the bottom voltage of the signal. It can be considered that only the magnetic permeability μ of. Therefore, the first signal S1 output from the adder circuit 92 shown in FIG. 3 does not fluctuate even if the second magnetic pattern of the medium 1 passes through the magnetic sensor element 40, and the signal shown in FIG. 7 (c4). It is the same.

  Thus, in the magnetic pattern detection apparatus 100 of the present embodiment, the first signal S1 obtained by adding the peak value and the bottom value of the signal output from the magnetic sensor element 40 in the addition circuit 92 is the residual magnetic flux density level of the magnetic pattern. By monitoring the first signal S1, it is possible to detect the presence and position of the first magnetic pattern formed by the magnetic ink containing the hard material. In addition, the second signal S2 obtained by subtracting the peak value and the bottom value of the signal output from the magnetic sensor element 40 in the subtraction circuit 93 is a signal corresponding to the magnetic permeability μ of the magnetic pattern. If monitored, it is possible to detect the presence and position of the second magnetic pattern formed by the magnetic ink containing the soft material. Therefore, the presence / absence and formation position of each of the magnetic patterns in the medium 1 of a plurality of types of magnetic patterns having different residual magnetic flux density Br and magnetic permeability μ when a magnetic field is applied are based on both the residual magnetic flux density level and the magnetic permeability level. Can be identified.

(Main effects of this form)
As described above, in the magnetic pattern detection apparatus 100 of the present embodiment, the moving speed v (mm / μsec) of the medium 1, the dimension T (mm) in the moving direction X of the magnetic sensor element 40, and the magnetic sensor element in the column direction Y the number of scans N unit time t _a (μsec) per 40, the following conditional expression _{(v × t a) ≦ (} T × N)
However, since N satisfies an integer greater than or equal to 2, the area where the magnetic sensor element 40 was located in the on state during the current scan and the position where the magnetic sensor element 40 was in the on state during the next scan. There is no gap between the area and Accordingly, even when a plurality of magnetic sensor elements 40 arranged in the column direction Y are scanned and the medium 1 is moved relative to the magnetic sensor 40, the magnetic pattern is reliably detected from the entire surface of the medium 1. be able to.

Further, in this embodiment, the unit time t _a is the one scan period for detecting one row of the magnetic pattern of the medium 1, obtained by the magnetic sensor element 40 by the scanning was conducted in accordance one scanning period A magnetic pattern for one column of the medium 1 is detected based on the data. That is, N scans (4 scans in this embodiment) are performed during one scan period for detecting a magnetic pattern for one column. For this reason, since a magnetic pattern for one column can be detected based on a plurality of data obtained by a plurality of scans, any of the data obtained by the magnetic sensor element 40 includes an influence such as noise. However, the influence of such noise can be mitigated.

  In this embodiment, the magnetic pattern for one column of the medium 1 is detected based on all data obtained by the magnetic sensor element 40 by N scans performed during one scanning period. The area where the magnetic sensor element 40 is projected at the same magnification partially overlaps in the current scan and the next scan. Therefore, the magnetic characteristics of the medium 1 can be detected with high accuracy.

  Further, in the magnetic pattern detection device 100 of this embodiment, the common magnetic sensor device 20 detects the presence / absence and formation position of each magnetic pattern based on both the residual magnetic flux density level and the magnetic permeability level. There is no time difference between the measurement and the permeability level measurement. Therefore, even when the measurement is performed while moving the magnetic sensor device 20 and the medium 1, the signal processing unit 60 can perform highly accurate detection with a simple configuration. In addition, since the transport device 10 is also required to have running stability only at a location that passes through the magnetic sensor device 20, the configuration can be simplified.

  Furthermore, according to the magnetic pattern detection apparatus 100 of the present embodiment, the medium 1 on which the magnetic pattern is formed by the magnetic ink including both the hard material and the soft material, and the material positioned between the hard material and the soft material are included. The magnetic pattern can also be detected for the medium 1 on which the magnetic pattern is formed with the magnetic ink. That is, with respect to a magnetic pattern whose magnetic characteristics are located between the first magnetic pattern and the second magnetic pattern, as shown in FIG. 7 (d1), the hysteresis loop has a hard loop as shown in FIG. 7 (b1). 7 is located in the middle between the hysteresis loop of the magnetic pattern of the material and the hysteresis loop of the magnetic pattern of the soft material shown in FIG. 7C1, so that the signal pattern shown in FIG. 7D4 can be obtained. In addition, the presence or absence and the formation position can be detected.

  Moreover, in the magnetic sensor device 20 of this embodiment, the magnetic field application magnets 30 are arranged as the first magnetic field application magnet 31 and the second magnetic field application magnet 32 on both sides of the magnetic sensor element 40 in the moving direction of the medium 1. Has been. For this reason, as shown in FIG. 1, the medium 1 moving in the direction indicated by the arrow X1 is magnetized by the first magnetic field application magnet 31, and then the magnetic sensor element 40 biases the medium 1 after magnetization. The magnetic flux can be detected in a state where a magnetic field is applied, and the medium 1 moving in the direction indicated by the arrow X2 is magnetized by the magnetic field applying second magnet 32, and then magnetized by the magnetic sensor element 40. The magnetic flux in a state where a bias magnetic field is applied to the medium 1 can be detected. Therefore, if the magnetic pattern detection apparatus 100 of this embodiment is used for a depositing / dispensing machine, it is possible to determine the authenticity of the deposited medium 1 and also to determine the authenticity of the dispensed medium 1. .

[Embodiment 2]
FIG. 9 is an explanatory diagram showing the position of the magnetic sensor element 40 for each scan in the magnetic pattern detection apparatus 100 according to the second embodiment of the present invention. The basic configuration of this embodiment is the same as that of the first embodiment. Accordingly, in the following description, common parts are denoted by the same reference numerals and description thereof is omitted.

Similarly to the first embodiment, the magnetic pattern detection apparatus 100 of this embodiment also has a moving speed v (mm / μsec) of the medium 1, a dimension T (mm) in the moving direction X of the magnetic sensor element 40, and a magnetic sensor element in the column direction Y. the number of scans N unit time t _a (μsec) per 40, the following conditional expression _{(v × t a) ≦ (} T × N)
However, N satisfies an integer of 2 or more. For this reason, as shown in FIG. 9, in the two consecutive scans of the first to fourth scans, the region where the magnetic sensor element 40 is in the on state is partially in the moving direction. overlapping. Here, in the first embodiment, the magnetic pattern for one column of the medium 1 is detected based on all the data obtained by the magnetic sensor element 40 by four scans performed during one scanning period. In this case, a magnetic pattern for one column of the medium 1 is detected based on data obtained by the magnetic sensor element 40 by a part of the N scans performed during one scanning period.

  More specifically, in the present embodiment, out of N scans performed during one scan period, an area in which the magnetic sensor element 40 is projected to the medium 1 at the same magnification is the medium in the current scan and the next scan. A magnetic pattern for one row of the medium 1 is detected based on a plurality of data obtained by the magnetic sensor element 40 by two or more and less than N scans partially overlapping in one movement direction X.

  For example, as shown in FIG. 9, the region where the magnetic sensor element 40 for the channel CH1 is located in the ON state at the time of the first scan is the magnetic sensor element 40 for the channel CH1 at the time of the third scan. Partially overlaps with the moving direction X in the region where the is located in the ON state. Therefore, in this embodiment, an averaging process is performed on the data obtained by the magnetic sensor element 40 during the first scan and the data obtained by the magnetic sensor element 40 during the third scan, Based on the processing result, the magnetic pattern for one column of the medium 1 is detected.

  Even when such a configuration is adopted, as in the first embodiment, the magnetic sensor element 40 is in the ON state in the current scan (first scan) and the next scan (third scan). Since the regions to be overlapped partially in the movement direction X, the magnetic characteristics of the medium 1 can be detected with high accuracy. In addition, since the magnetic pattern for one column can be detected based on the data obtained by the two scans, even if any of the data obtained by the magnetic sensor element 40 includes the influence of noise or the like, There are effects such as the effect of such noise being mitigated.

The moving velocity v of the medium 1, the dimension T in the moving direction X of the magnetic sensor element 40, by the unit of the magnetic sensor element 40 time t _a (μsec) number of scans N etc. per in the column direction Y during one scanning period Of the N scans performed at the same time, the region in which the magnetic sensor element 40 is projected onto the medium 1 at the same magnification is in contact with the current scan and the next scan without overlapping in the medium 1 movement direction X. The magnetic pattern for one column of the medium 1 may be detected based on a plurality of data obtained by the magnetic sensor element 40 by the above scan and less than N times.

[Embodiment 3]
FIG. 10 is an explanatory diagram showing the position of the magnetic sensor element 40 and its sensing range for each scan in the magnetic pattern detection apparatus 100 according to the third embodiment of the present invention. The basic configuration of this embodiment is a mode 1 the same like implementation. Accordingly, in the following description, common parts are denoted by the same reference numerals and description thereof is omitted.

Similarly to the first embodiment, the magnetic pattern detection apparatus 100 of this embodiment also has a moving speed v (mm / μsec) of the medium 1, a dimension T (mm) in the moving direction X of the magnetic sensor element 40, and a magnetic sensor element in the column direction Y. the number of scans N unit time t _a (μsec) per 40, the following conditional expression _{(v × t a) ≦ (} T × N)
However, N satisfies an integer of 2 or more. For this reason, as shown in FIG. 10, in the two consecutive scans among the first to fourth scans, the region where the magnetic sensor element 40 is located in the on state is partially in the movement direction. overlapping. Here, in the first embodiment, the magnetic pattern for one column of the medium 1 is detected based on all the data obtained by the magnetic sensor element 40 by four scans performed during one scanning period. In this case, a magnetic pattern for one column of the medium 1 is detected based on data obtained by the magnetic sensor element 40 by a part of the N scans performed during one scanning period.

  More specifically, as shown in FIG. 10, the magnetic sensor element 40 has an actual sensing range wider than the area projected onto the medium 1 at the same magnification, and the sensing range of the magnetic sensor element 40 in the moving direction X of the medium 1. Has a dimension S (mm) larger than the dimension T in the movement direction X. Therefore, in the present embodiment, out of N scans performed during one scan period, the sensing range partially overlaps in the moving direction X of the medium 1 in the current scan and the next scan at least twice and less than N times. The magnetic pattern for one column of the medium 1 is detected on the basis of a plurality of data obtained by the magnetic sensor element by the scan.

  For example, as shown in FIG. 10, the sensing range when the magnetic sensor element 40 for the channel CH1 is turned on during the first scan is the same as the magnetic field for the channel CH1 during the third scan. It partially overlaps the sensing range when the sensor element 40 is turned on. Therefore, in this embodiment, an averaging process is performed on the data obtained by the magnetic sensor element 40 during the first scan and the data obtained by the magnetic sensor element 40 during the third scan, Based on the processing result, the magnetic pattern for one column of the medium 1 is detected.

  Even when such a configuration is adopted, the sensing range by the magnetic sensor element 40 moves between the current scan (first scan) and the next scan (third scan), as in the first embodiment. Since it partially overlaps in the direction X, the magnetic characteristics of the medium 1 can be detected with high accuracy. In addition, since the magnetic pattern for one column can be detected based on the data obtained by the two scans, even if any of the data obtained by the magnetic sensor element 40 includes the influence of noise or the like, There are effects such as the effect of such noise being mitigated.

The moving velocity v of the medium 1, the dimension T in the moving direction X of the magnetic sensor element 40, by the unit of the magnetic sensor element 40 time t _a (μsec) number of scans N etc. per in the column direction Y during one scanning period Of the N scans performed during the scan period, of the N scans performed during one scan period, the sensing range is in contact with the current scan and the next scan without overlapping in the moving direction X of the medium 1. The magnetic pattern for one column of the medium 1 may be detected based on a plurality of data obtained by the magnetic sensor element 40 by the above scan and less than N times.

(Other embodiments)
In the above embodiment, when the medium 1 and the magnetic sensor device 20 are moved relative to each other, the medium 1 is moved. However, a configuration in which the medium 1 is fixed and the magnetic sensor device 20 moves may be employed. Moreover, in the said form, although the permanent magnet was used for the magnet 30 for magnetic field application, you may use an electromagnet.

  In the above embodiment, the magnetic pattern for one column of the medium 1 based on the data obtained by the magnetic sensor element 40 by four or two of the N scans performed during one scan period. Although an example in which the magnetic sensor element 40 is detected has been described, one column of the medium 1 is determined based on data obtained by the magnetic sensor element 40 by one or three of the N scans performed during one scan period. The medium 1 may be detected based on data obtained by the magnetic sensor element 40 by one scan or a plurality of scans out of N scans performed during one scan period. It is sufficient to detect the magnetic pattern for one column. More specifically, N scans are performed during one scan period, and data is acquired via the magnetic sensor element 40 for each scan. In determining the magnetic pattern for one column of the medium 1, Of the N scans performed during one scan period, data obtained by the magnetic sensor element 40 by one scan or a plurality of scans may be used.

Further, in the above-described embodiment, out of N scans performed during one scan period, the current scan and the next scan were obtained by a plurality of scans in which the sensing range of the magnetic sensor element 40 was connected. Although the example in which the magnetic pattern for one column of the medium 1 is detected based on the data has been described, the magnetic sensor element 40 in the current scan and the next scan among the N scans performed during one scan period. it may detect one row of the magnetic pattern of the medium 1 on the basis of data obtained by a plurality of scans spaced apart without sensing range lead in. Further, the data obtained by the scan in which the sensing range in the magnetic sensor element 40 is connected in the current scan and the next scan and the sensing range in the magnetic sensor element 40 in the current scan and the next scan are not connected. The magnetic pattern for one column of the medium 1 may be detected based on the data obtained by the scan.

  Further, of N scans performed during one scanning period, it is variable which one of the magnetic patterns for one column of the medium 1 is detected based on data obtained by the magnetic sensor element 40 at the time of scanning. It may be configured to be arbitrarily set by a command to the digital signal processing unit 90 from an upper control unit or the outside. With this configuration, it is possible to realize an optimum operation according to the type of the medium 1, the detection accuracy required for the magnetic pattern detection device 100, and the like.

DESCRIPTION OF SYMBOLS 1 Medium 11 Medium moving path 20 Magnetic sensor apparatus 40 Magnetic sensor element 48 Excitation coil 49 Detection coil 60 Signal processing part 100 Magnetic pattern detection apparatus

Claims (12)

A magnetic pattern detection device comprising: a magnetic sensor element that detects magnetic characteristics from a medium; and a transport mechanism that moves the medium relative to the magnetic sensor element.
A plurality of the magnetic sensor elements are arranged in a column direction orthogonal to the moving direction of the medium,
The moving speed of the medium by the transport mechanism is v (mm / μsec),
The dimension of the magnetic sensor element in the moving direction is T (mm),
When the number of scans per unit time t _a (μsec) of the magnetic sensor element in the column direction is N times,
The moving velocity v, the unit time t _a, the dimension T and the number of scans N, the following conditional expression _{(v × t a) ≦ (} T × N)
However, the magnetic pattern detection apparatus characterized in that N satisfies an integer of 2 or more. The unit time t _a is the one scan period for detecting one row of the magnetic pattern of the medium,
2. The magnetic pattern detection device according to claim 1, wherein a magnetic pattern for one column of the medium is detected based on data obtained by the magnetic sensor element by scanning performed during the one scanning period. .   A magnetic pattern for one column of the medium is detected based on data obtained by the magnetic sensor element by one scan or a plurality of scans out of N scans performed during the one scan period. The magnetic pattern detection apparatus according to claim 2.   A magnetic pattern for one column of the medium is detected based on data obtained by the magnetic sensor element by a plurality of scans out of N scans performed during the one scan period. The magnetic pattern detection apparatus according to claim 3.   5. The magnetic pattern for one column of the medium is detected based on all data obtained by the magnetic sensor element by N scans performed during the one scan period. Magnetic pattern detection device.   Of the N scans performed during the one scan period, the region in which the magnetic sensor element is projected to the medium at the same magnification partially overlaps in the moving direction in the current scan and the next scan. A plurality of data obtained by the magnetic sensor element by the above scan and less than N scans, or an area where the magnetic sensor element is projected at the same magnification on the medium is the moving direction in the current scan and the next scan in the moving direction. 5. The magnetic pattern for one column of the medium is detected based on a plurality of data obtained by the magnetic sensor element by scanning at least twice and less than N times in contact with each other without overlapping. The magnetic pattern detection apparatus described in 1.   Of the N scans performed during the one scan period, the region in which the magnetic sensor element is projected to the medium at the same magnification partially overlaps in the moving direction in the current scan and the next scan. 7. The magnetic pattern detection device according to claim 6, wherein a magnetic pattern for one column of the medium is detected based on a plurality of data obtained by the magnetic sensor element by scanning less than N times. . The sensing range in the moving direction of the magnetic sensor element is larger than the dimension T in the moving direction of the magnetic sensor element,
Of the N scans performed during the one scan period, the magnetic sensing element is formed by scanning the sensing range at least twice and less than N times that partially overlap in the moving direction in the current scan and the next scan. Or a plurality of data obtained by the magnetic sensor element by two or more and less than N scans in which the sensing range touches the moving direction in the current scan and the next scan without overlapping in the moving direction. The magnetic pattern detection apparatus according to claim 4, wherein a magnetic pattern for one column of the medium is detected based on the data.   Of the N scans performed during the one scan period, the magnetic sensing element is formed by scanning the sensing range at least twice and less than N times that partially overlap in the moving direction in the current scan and the next scan. The magnetic pattern detection apparatus according to claim 8, wherein a magnetic pattern for one column of the medium is detected based on the plurality of data obtained in step 1.   In detecting a magnetic pattern for one column of the medium based on a plurality of data obtained by the magnetic sensor element during the one scanning period, an averaging process is performed on the plurality of data. The magnetic pattern detection apparatus according to any one of claims 4 to 9.   Of the N scans performed during the one scan period, it is variable whether the magnetic pattern for one column of the medium is detected based on the data obtained by the magnetic sensor element at the time of the scan. The magnetic pattern detection device according to claim 3, wherein the magnetic pattern detection device is provided. The magnetic sensor element is excited by an excitation signal and outputs a signal,
The excitation signal has a frequency at which a signal component of the excitation signal for a plurality of cycles is included in a signal output from each of the plurality of magnetic sensor elements during one scan. The magnetic pattern detection apparatus according to any one of 1 to 11.