JP2015197687A - Magnetic field generator, magnetic recording medium processing device, and control method of the magnetic recording medium processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic field generator capable of suppressing an increase in the scale of a configuration, changing a frequency of a magnetic field to be generated, generating a frequency changeable magnetic field, and surely preventing a fraudulent acquisition of magnetic data with high reliability, a magnetic recording medium processing device, and a control method of the magnetic recording medium processing device.SOLUTION: A magnetic field generator includes: a resonance section 511 that includes a resonance circuit in which an inductor L51 and a capacitor C51 are connected between a first node ND52 and a second node ND53, receives a drive voltage at the first node, and generates a magnetic field by resonating at a frequency set in a state where the second node is connected to a reference potential part; and a frequency change section 53 capable of changing a resonance frequency of the resonance section.

Description

  The present invention relates to a magnetic field generator for generating a disturbing magnetic field, a magnetic recording medium processing apparatus including a magnetic field generator for reading magnetic data recorded on a magnetic recording medium, and writing magnetic data to a magnetic recording medium, and magnetic recording. The present invention relates to a method for controlling a medium processing apparatus.

  2. Description of the Related Art Conventionally, a card reader as a magnetic recording medium processing apparatus that reads magnetic data recorded on a card-like magnetic recording medium (hereinafter referred to as “card”) as a magnetic recording medium or writes magnetic data to a card has been used. Widely used. This type of card reader is mounted and used in a host device such as an ATM (Automated Teller Machine) installed in a financial institution such as a bank. In the industry such as a financial institution where a card reader is used, a so-called fraudulent person attaches a magnetic head in front of a card insertion slot of the card reader and illegally obtains magnetic data on the card with this magnetic head. Skimming is a big problem.

  Therefore, conventionally, a magnetic field generator for generating a disturbing magnetic field for obstructing reading of magnetic data of a card by a skimming magnetic head (hereinafter referred to as “skimming magnetic head”) attached in front of the card insertion slot. Has been proposed (for example, see Patent Document 1). In the card reader described in Patent Document 1, a magnetic field (magnetism) generating device is provided in the card insertion slot of the card reader, and for the skimming by a disturbing magnetic field (magnetism) at a single frequency emitted from the magnetic field (magnetism) generating device. A technique for preventing the magnetic head from reading the magnetic data of the card user is disclosed.

  Since the magnetic data recorded on the magnetic card differs depending on the standard (specification), the magnetic data recorded on the magnetic card may not be able to be disturbed in this frequency band with the disturbing magnetic field at a single frequency. There were cases where it was not enough.

  Therefore, Patent Document 2 proposes a card processing device including a magnetic field generator that generates a plurality of disturbing magnetic fields. The card processing apparatus described in Patent Document 2 generates magnetic fields having different frequencies by driving a plurality of magnetic field radiation sources from a plurality of driving sources having different frequencies.

JP 2001-67524 A (or Japanese Patent No. 393696) JP 2007-164533 A

  However, in the magnetic field generator used in Patent Document 2, a plurality of magnetic field radiation sources having different frequencies are necessary, and a plurality of magnetic field radiation sources are also necessary. As a result, this magnetic field generator selects the frequency even when the overall configuration is large and it has been found that it does not correspond to the recording density of the magnetic data recorded on the magnetic card. Since this is not possible, a disturbing magnetic field corresponding to the frequency is also generated, and there is a problem that unnecessary magnetic field generation is performed.

  Therefore, the problem of the present invention is that it is possible to suppress an increase in the size of the configuration, to change the frequency of the generated magnetic field, to generate a magnetic field that changes in frequency, and to obtain unauthorized acquisition of magnetic data with high accuracy. It is an object of the present invention to provide a magnetic field generation device, a magnetic recording medium processing device, and a control method for the magnetic recording medium processing device that can be reliably prevented.

  A magnetic field generation device according to a first aspect of the present invention includes a drive power supply unit that supplies a drive voltage, a reference potential unit, and a resonance circuit in which an inductor and a capacitor are connected between a first node and a second node. A resonance unit that receives the drive voltage at the first node and resonates at a frequency set in a state where the second node is connected to a reference potential unit, and generates a magnetic field; and A frequency changing unit capable of changing the resonance frequency. As a result, an increase in the size of the configuration can be suppressed, the frequency of the generated magnetic field can be changed, a magnetic field with a changing frequency can be generated, and unauthorized acquisition of magnetic data can be reliably prevented with high accuracy. Is possible.

  A magnetic recording medium processing apparatus according to a second aspect of the present invention includes a magnetic generator including a magnetic field generator that generates a magnetic field by a resonance unit, and a drive control circuit that drives and controls the magnetic field generator, and the magnetic generator The drive control circuit includes a drive power supply unit that supplies a drive voltage, a reference potential unit, and a frequency change unit that can change a resonance frequency of the resonance unit, and the resonance unit includes a first node and Including a resonance circuit in which an inductor and a capacitor are connected to a second node, receiving the drive voltage at the first node, and changing the frequency in a state where the second node is connected to a reference potential section Resonates at a frequency set by the unit to generate a magnetic field. As a result, an increase in the size of the configuration can be suppressed, the frequency of the generated magnetic field can be changed, a magnetic field with a changing frequency can be generated, and unauthorized acquisition of magnetic data can be reliably prevented with high accuracy. Is possible.

  Preferably, the frequency changing unit changes the resonance frequency of the resonance unit to a plurality of different resonance frequencies during a period in which a magnetic field is generated by the resonance unit. As a result, a disturbing magnetic field whose frequency changes can be generated at an appropriate timing, and it is extremely difficult to read the magnetic data of the card-like recording medium by a device equipped with a skimming magnetic head.

  Preferably, the resonant circuit is formed by connecting the inductor and one or more capacitors in parallel, and the frequency changing unit includes a switching unit that switches connection between the one or more capacitors and the inductor. Including. According to the configuration using the plurality of capacitors, a magnetic field whose frequency changes can be generated without a plurality of magnetic field radiation sources (coils and the like) and a plurality of driving sources for the magnetic field radiation sources.

  Preferably, the resonator is connected between the second node of the resonance unit and the reference potential unit, and is switched between a conduction state and a non-conduction state according to a control signal, and the second node of the resonance unit A resonance drive unit including a drive switching element that switches between a connection state and a non-connection state with the reference potential unit;

  Preferably, the resonance unit is connected between the first node of the resonance unit and the discharge potential unit, and is switched between a conduction state and a non-conduction state in response to a first magnetic field generation stop signal. A discharge driving unit including a first switching element that switches between a connection state and a non-connection state between the first node and the discharge potential unit, wherein the drive power supply unit includes the supply source of the drive voltage and the resonance Connected to the first node of the switching unit, and switched between a conducting state and a non-conducting state according to a second magnetic field generation stop signal, and the driving voltage supply unit and the first node of the resonance unit You may comprise so that the 2nd switching element which switches a connection state and a non-connecting state may be included. As a result, the output of the disturbing magnetic field can be increased, and illegal acquisition of magnetic data can be reliably prevented with high accuracy.

  A control method for a magnetic recording medium processing device according to a third aspect of the present invention includes a magnetic generator including a magnetic field generator that generates a magnetic field by a resonance unit, and a drive control circuit that drives and controls the magnetic field generator, The drive control circuit of the magnetic generator includes a drive power supply unit that supplies a drive voltage, a reference potential unit, and a frequency change unit that can change a resonance frequency of the resonance unit. A resonance circuit in which an inductor and a capacitor are connected between the first node and the second node, the drive voltage is received by the first node, and the second node is connected to a reference potential portion When controlling magnetic field generation in a magnetic recording medium processing apparatus that generates a magnetic field by resonating at a frequency set by the frequency changing unit, a resonance frequency of the resonant unit is set during a period in which the magnetic field is generated by the resonant unit. Changing to a plurality of different resonance frequencies. As a result, an increase in the size of the configuration can be suppressed, the frequency of the generated magnetic field can be changed, a magnetic field with a changing frequency can be generated, and unauthorized acquisition of magnetic data can be reliably prevented with high accuracy. Is possible. Further, a disturbing magnetic field whose frequency changes can be generated at an appropriate timing, and it is difficult to read data on the card-like recording medium by the skimming device.

  According to the present invention, an increase in the size of the configuration can be suppressed, the frequency of the generated magnetic field can be changed, a magnetic field with a changing frequency can be generated, and unauthorized acquisition of magnetic data can be ensured with high accuracy. It becomes possible to prevent.

It is a figure which shows schematic structure of the principal part of the card reader as a magnetic recording medium processing apparatus concerning embodiment of this invention. It is a figure which shows schematic structure of the card insertion part of the card reader as a magnetic recording medium processing apparatus which concerns on this embodiment. It is a block diagram which shows schematic structure of the control part of the card reader shown in FIG. 1, and its related part. It is a figure which shows typically the state by which the magnetic head apparatus for skimming was attached to the apparatus exterior side. It is a circuit diagram showing a magnetic field generation part, a drive control circuit, and a frequency change part of a magnetic field generator concerning a 1st embodiment of the present invention. It is a circuit diagram which shows the 1st structural example of the frequency change part which concerns on this embodiment. It is a circuit diagram which shows the 2nd structural example of the frequency change part which concerns on this embodiment. It is a circuit diagram which shows the 3rd structural example of the frequency change part which concerns on this embodiment. It is a circuit diagram which shows the 4th structural example of the frequency change part which concerns on this embodiment. It is a wave form chart for explaining operation of the magnetic field generator concerning a 1st embodiment. It is a circuit diagram which shows the magnetic field generation part of the magnetic field generator which concerns on the 2nd Embodiment of this invention, a drive control circuit, and a frequency change part. It is a circuit diagram which shows more specifically the principal part of the drive control circuit which concerns on the 2nd Embodiment of this invention, In order to demonstrate focusing on the operation | movement at the time of the magnetic field generation stop of the magnetic field generator which concerns on 2nd Embodiment. FIG. It is a wave form diagram for demonstrating operation | movement of the magnetic field generator which concerns on 2nd Embodiment. It is a circuit diagram which shows the magnetic field generation part of the magnetic field generator which concerns on the 3rd Embodiment of this invention, a drive control circuit, and a frequency change part. It is a flowchart for demonstrating the operation | movement at the time of card taking-in. It is a flowchart for demonstrating an example of the operation | movement of disturbance magnetic field generation | occurrence | production. It is a figure for demonstrating the operation | movement at the time of card | curd taking-in. It is a flowchart for demonstrating the operation | movement at the time of card | curd discharge. It is a figure for demonstrating the operation | movement at the time of card | curd discharge. It is a block diagram which shows the other schematic structure of the control part of the card reader shown in FIG. 1, and its related part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the present embodiment, an example of a card reader that reads magnetic data or records magnetic data recorded on a card-like recording medium or the like will be described as a magnetic recording medium processing apparatus.

  In the following, first, the schematic configuration of the card reader according to the present embodiment will be described, and then the specific circuit configuration and operation of the magnetic field generator that generates the disturbing magnetic field will be described. The card reading and discharging operations of this card reader will be described in relation to the drive timing of the magnetic field generator.

[Schematic configuration of card reader]
FIG. 1 is a diagram showing a schematic configuration of a main part of a card reader as a magnetic recording medium processing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a schematic configuration of a card insertion portion of a card reader as a magnetic recording medium processing apparatus according to the present embodiment.

  The card reader 10 of the present embodiment is a magnetic recording medium processing device for reading magnetic data recorded on a magnetic stripe mp formed on a card MC and / or writing magnetic data to the card MC. For example, it is mounted and used in a predetermined host device such as an automatic transaction device (ATM (Automated Teller Machine)) installed in a financial institution or the like. The card reader 10 is disposed on the back side of the front panel 20 constituting the front surface of the housing of the host device. The front panel 20 is formed with an opening 21 into which a card MC as a magnetic recording medium on which magnetic data is recorded is inserted or ejected.

  As shown in FIG. 1, the card reader 10 includes a card processing unit 30 that reads magnetic data recorded on the card MC and / or writes magnetic data to the card MC, and a card into which the card MC is inserted and ejected. A card insertion unit 31 in which an insertion port 311 is formed, a control unit 40 for controlling the card reader 10, and a magnetic field generator for generating a disturbing magnetic field for preventing reading of magnetic data of the card MC with a magnetic head for skimming. 50. Inside the card reader 10 is formed a card transport path 32 through which the card MC inserted from the card insertion slot 311 is transported. The control unit 40 that performs various controls of the card reader 10 is mounted on a circuit board (not shown).

  In the present embodiment, the card MC is transported in the X direction (left-right direction) in FIGS. That is, the X direction is the card MC transport direction. Further, the Z direction (vertical direction) in FIG. 1 is the thickness direction of the card MC, and the Y direction (perpendicular direction in FIG. 1) perpendicular to the X direction and the Z direction is the card. It is the width direction (short width direction) of MC.

  The card MC is, for example, a rectangular vinyl chloride card having a thickness of about 0.7 to 0.8 mm. A magnetic stripe mp is formed on the card MC. Note that an IC chip may be fixed to the card MC, or a communication antenna may be incorporated. The card MC may be a PET (polyethylene terephthalate) card having a thickness of about 0.18 to 0.36 mm, or may be a paper card having a predetermined thickness.

  The card processing unit 30 detects the presence or absence of a card MC in the card transport path 32, a card transport mechanism 33 for transporting the card MC in the card transport path 32, a magnetic head 34 for reading and writing magnetic data, and the card MC in the card transport path 32. And a photosensor 35 for the purpose.

  The card transport mechanism 33 includes three transport rollers 331 to 333, a drive motor 36 that rotationally drives the transport rollers 331 to 333, and a power transmission mechanism that transmits the power of the drive motor 36 to the transport rollers 331 to 333 ( (Not shown). In addition, the card transport mechanism 33 includes pad rollers 334 to 336 that are opposed to the transport rollers 331 to 333 and are biased toward the transport rollers 331 to 333. The three transport rollers 331 to 333 are arranged with a predetermined interval in the card MC transport direction.

  Each of the conveying rollers 331, 332, and 333 is rotationally driven by the driving motor 36 under the control of the control unit 40.

  As shown in FIG. 1, in the magnetic head 34, the rotation center of the conveyance row 332 arranged at the center of the card processing unit 30 and the center of the magnetic head 34 substantially coincide with each other in the X direction in the conveyance direction of the card MC. Are arranged as follows. In addition, a counter roller 335 for applying a biasing force toward the magnetic head 34 to the card MC passing through the card transport path 32 is disposed opposite to the magnetic head 34.

  The photosensor 35 is an optical sensor having a light emitting element and a light receiving element. In the present embodiment, the magnetic head 34 reads the magnetic data recorded in the magnetic stripe mp immediately after the photosensor 351 detects the leading edge of the card MC, and immediately before the photosensor 351 no longer detects the card MC. Finish reading. That is, in this embodiment, it is possible to detect whether or not magnetic data is being read by the magnetic head 34 by the photosensor 351.

  The card insertion unit 31 includes a card insertion detection mechanism 37 as a detection mechanism unit for detecting whether or not a card MC has been inserted from the card insertion port 311, a shutter 38 for opening and closing the card transport path 32, and a magnetic stripe mp And a pre-head (magnetic head) 39 for reading the magnetic data recorded on the head.

  For example, as shown in FIG. 2, the card insertion detection mechanism 37 is turned on when one end in the width direction of the card MC to be inserted is pressed in the horizontal direction (Y direction), and is released away from the pressed state. And a card width sensor (card detection sensor) 371 that is turned off.

  The card insertion detection mechanism 37 includes, for example, a card width sensor (card detection sensor) that detects whether or not a sensor lever (not shown) that can contact one end in the width direction of the card MC is in contact with the card MC. It is also possible to configure. In this case, the sensor lever is rotatable about a predetermined rotation axis, and is disposed in the card transport path 32 so as to appear and retract.

  The card width sensor 371 may be an optical sensor having a light emitting element and a light receiving element. Further, the card insertion detection mechanism 37 may be a mechanical detection mechanism having a contact point that directly contacts an end portion in the width direction of the card MC.

  The pre-head 39 is disposed in the vicinity of the card insertion slot 311 in the card MC transport direction. Specifically, the pre-head 39 is disposed in the vicinity of the card insertion detection mechanism 37, for example, in the vicinity of a contact portion of the sensor width sensor 371 with the card MC. In the present embodiment, the pre-head 39 reads the magnetic data recorded on the magnetic stripe mp immediately after the card insertion detection mechanism 37 detects the leading edge of the card MC, and immediately before the card insertion detection mechanism 37 no longer detects the card MC. Finish reading magnetic data. That is, in the present embodiment, it is possible to detect whether or not magnetic data is being read by the pre-head 39 by the card insertion detection mechanism 37.

  The magnetic field generator 50 includes a resonance unit (resonance circuit) that constitutes the magnetic field generation unit, and includes a configuration of the resonance unit and a drive control circuit thereof, a configuration of a frequency change unit that changes the resonance frequency of the resonance unit, and the like. A specific configuration thereof will be described in detail later with reference to a plurality of embodiments.

[Schematic configuration of card reader controller]
FIG. 3 is a block diagram showing a schematic configuration of the control unit 40 and related portions of the card reader 10 shown in FIG. FIG. 3 also shows a configuration example of an inductor and a connection example with a capacitor of a magnetic field generator that generates a disturbing magnetic field provided in the card reader according to the present embodiment.

  The control unit 40 is mounted on a circuit board (not shown). The control unit 40 controls various parts of the card reader 10 and includes, for example, a CPU 41. The control unit 40 controls the card MC carrying operation, the reading operation by the magnetic head 34, and the like according to the control program stored in the built-in ROM. Furthermore, a photo sensor 35, a card detection (card width) sensor 371, and a pre-head 39 are connected to the control unit 40, and output signals from these components are input. In addition, a drive motor 36 is connected to the control unit 40 via a driver 42. Furthermore, an encoder 361 is connected to the control unit 40, and an output signal from the encoder 361 for detecting the rotation state of the drive motor 36 and the like is input.

  In the present embodiment, the control unit 40 is connected to a magnetic field generator 50 that generates a disturbing magnetic field to a skimming magnetic head that is improperly attached. The magnetic field generator 50 performs drive control such as generation of a magnetic field and stop of generation of the magnetic field according to the card detection result of the card detection (card width) sensor 371, the magnetic detection result of the pre-head 39, and the like.

[Schematic configuration of magnetic field generator]
The magnetic field generator 50 of the present embodiment includes a magnetic field generator 51, a drive control circuit (drive controller) 52 that drives and controls the generation of a magnetic field by the magnetic field generator 51 and the stop of the magnetic field generator 51, and the resonance frequency is changed. The frequency change part 53 to perform is provided.

  The magnetic field generator 51 includes an inductor L1 for generating a magnetic field. For example, as shown in FIG. 3, the inductor L1 is formed by winding a coil CL around an iron core FC. In the present embodiment, the magnetic field generation unit 51 is disposed in the card insertion unit 31. In the magnetic field generation unit 51, as will be described in detail later, the inductor L1 is connected to the capacitor C1 or C2 to form a resonance unit (parallel resonance circuit), and continuously generates a disturbing magnetic field. It is also configured to increase the output of the disturbing magnetic field.

  Furthermore, the magnetic field generator 50 changes the resonance frequency by changing either or both of the overall inductance and capacitance (capacitance) of the resonance circuit formed by connecting the inductor and the capacitor in parallel. A change unit 53 is included.

  As a method for changing the inductance, for example, a plurality of inductors L1 are provided and a connection state of one or a plurality of inductors contributing to resonance of the resonance circuit is selectively switched, or a plurality (two or more) of inductors L1 having different inductances are provided. A method of connecting an inductor that contributes to resonance at a desired resonance frequency can be employed.

  As a method of changing the capacitance (capacitance), for example, a plurality of capacitors C1 are provided, and a connection state of one or a plurality of capacitors contributing to resonance of the resonance circuit is selectively switched, or a plurality of capacitors C1 having different capacitances (2 A method of connecting capacitors that contribute to resonance at a desired resonance frequency and the like can be adopted. According to the configuration using the plurality of capacitors, a magnetic field whose frequency changes can be generated without a plurality of magnetic field radiation sources (coils and the like) and a plurality of driving sources for the magnetic field radiation sources.

  As a more practical configuration, the frequency changing unit 53 configured to change the overall capacitance of the parallel resonant circuit will be described in detail later in association with a plurality of configuration examples. For example, in the magnetic field generator 50 applied to a card reader, the resonance frequency to be changed, in other words, the resonance frequency that can be set by the magnetic field generator 50 is, for example, magnetic data as long as it can have two frequencies. Can be reliably prevented with high accuracy. Here, as the two frequencies, for example, frequencies corresponding to the conveyance speeds of cards having a recording density (data roughness) of 75 bpi and 210 bpi according to the JIS standard can be adopted. Moreover, the frequency based on the Radio Law is applied as the frequency to be changed (set). In Japan, a frequency of less than 10 kHz is applied. A configuration example of the frequency changing unit 53 that changes two frequencies at a predetermined period will be described in detail later.

  In the magnetic field generator 50, an alternating current or a direct current is passed through the coil CL under the control of the drive control circuit 52 that is integrally controlled by the control unit 40. When an electric current is passed, it is configured and arranged so that a disturbing magnetic field is generated in the outer portion of the opening 21 or the card insertion portion 31. The generation region of the disturbing magnetic field is configured to include a passage region of the magnetic stripe mp formed on the magnetic card MC inserted or ejected through the card insertion portion 31.

  As shown in FIG. 1, the magnetic field generator 50 having the above configuration has a magnetic field generator 51, a drive control circuit 52, and a frequency changer 53 in the vicinity of the inner side (back side) of the front panel 20 as shown in FIG. 1. Can be arranged including the entire circuit. However, for example, only the resonance part as a magnetic field generation part constituted by a coil (inductor) L1 and a capacitor C1 (a plurality, for example, two in the embodiment described later) is arranged in the vicinity of the inner side of the front panel 20, and the remaining parts Various modes are possible, such as arranging the circuit system at another position, for example, the control unit 40 side.

  FIG. 4 is a diagram schematically illustrating a state in which a skimming magnetic head (including a skimmer) device is attached to the outside of the device.

  In the card reader 10, when the card MC is inserted, the tip of the card MC is inserted into the card insertion slot 311, and at the same time, the card MC is transported at a constant speed by the transport roller 331. Similarly, when the magnetic card MC is ejected, the magnetic card MC is transported at a constant speed by the transport roller 331 until the magnetic card MC is substantially ejected from the card insertion port 311 to the outside.

  Accordingly, when a skimmer including a skimming magnetic head and a magnetic reading circuit (an apparatus that illegally reads magnetic card data) is attached to the outside of the card insertion slot 311, a constant speed is provided along the skimming magnetic head. Will move the card. For this reason, it is possible to read the recorded data of the card by a magnetic head attached to the outside of the card slot.

  In the card reader 10 according to the present embodiment, for example, as shown in FIG. 4, even if the skimmer 60 including the magnetic head 61 is illegally attached to the surface of the front panel 20 where the card slot opening 21 is formed, The reading operation of the card MC by the skimming magnetic head 61 can be prevented by the disturbing magnetic field by the magnetic field generator 50.

  That is, in the present embodiment, it is possible to continue the generation of the disturbing magnetic field, change the resonance frequency, generate a magnetic field whose frequency changes, and increase the illegal acquisition of magnetic data. A magnetic field generator 50 having a characteristic configuration as described below, which can be reliably prevented with accuracy, is employed.

[Configuration Example of Magnetic Field Generating Unit 51, Drive Control Circuit 52, and Frequency Changing Unit 53 of Magnetic Field Generating Device 50]
Next, specific circuit configurations and operations of the magnetic field generator 51, the drive control circuit 52, and the frequency changing unit 53 of the magnetic field generator 50 will be described in detail as a plurality of embodiments. In the following description, the resonance unit 511 constituting the magnetic field generation unit 51 of the magnetic field generation device 50 according to the first embodiment described in association with FIG. 5 basically includes the coil L and the capacitor C that are inductors. It has an LC parallel resonance circuit formed by connection, and has a function of continuously generating a magnetic field by this LC parallel resonance circuit.

  Further, in the present embodiment, the magnetic field generator 51 has a function of generating a stronger magnetic field than the conventional one using only a coil by an LC resonance circuit. Thereby, since the magnetic field generator 50 continuously generates a magnetic field over a predetermined period, it is possible to increase the output of the disturbing magnetic field as a result, and reliably acquire magnetic data using the skimming magnetic head. Can be prevented.

  Furthermore, in the present embodiment, the magnetic field generation unit 51 has a function of changing the resonance frequency, for example, periodically (or randomly) by the switching operation by the frequency changing unit 53. Thereby, the magnetic field generator 50 can generate the interference magnetic fields having a plurality of frequencies. Moreover, the magnetic field generator 50 can generate a disturbing magnetic field continuously. As a result, it is possible not only to increase the output of the disturbing magnetic field, but also to change the resonance frequency, to generate a magnetic field whose frequency changes, and to illegally store magnetic data using the skimming magnetic head. Can be reliably prevented with high accuracy.

  More specifically, in this embodiment, the resonance unit 511 has a function of changing the resonance frequency, for example, periodically (or randomly) by the switching operation by the frequency changing unit 53, and a plurality of (in FIG. 5) In the example, it is configured to generate a disturbing magnetic field having two frequencies. As a result, it is possible not only to increase the output of the disturbing magnetic field, but also to change the resonance frequency, to generate a magnetic field whose frequency changes, and to illegally store magnetic data using the skimming magnetic head. Can be reliably prevented with high accuracy. Further, by generating a disturbing magnetic field whose frequency changes at an appropriate timing, it is possible to make it extremely difficult to read the data of the card MC by the skimming device. Further, by using a plurality of capacitors, a magnetic field whose frequency changes can be generated even if there are not a plurality of magnetic field radiation sources (coils, etc.) or a drive source for the magnetic field radiation source, thereby preventing an increase in size of the apparatus. be able to.

  Note that the magnetic field generator 50 of the present embodiment can be configured to further have the following configuration. As described above, in the magnetic field generator 50, since the output of the disturbing magnetic field is increased, a strong magnetic field remains even when the drive control is stopped, that is, the pre-head 39 is caused by the residual magnetic field accompanying the remaining resonance energy. The magnetic data may not be read. As a result, the card reader 10 opens the shutter 38 based on the magnetic data output signal from the pre-head 39 in order to prevent foreign matter from being mixed in. However, if the pre-head 39 cannot read the magnetic data, The pre-head 39 may erroneously detect due to the magnetic field being applied. Therefore, the responsiveness of the opening / closing control of the shutter 38 is deteriorated. As a result, when the user inserts the card quickly, there is a possibility that an event such as the card MC hitting (collision) with the shutter 38 may occur. In order to solve these problems, for example, in the card reader 10, the interval (distance) until the arrangement of the pre-head 39 and the shutter 38 in the card conveying direction is attenuated until the resonance energy is not affected by the magnetic head. It is arranged to become. Further, it may be set to an output that can attenuate the resonance energy. Furthermore, the card transport path 32 may be loaded when a card is transported to save time reaching the shutter 38.

  Further, as will be described later, the magnetic field generator 50B according to the second embodiment quickly uses the resonance energy in the LC resonance circuit that generates the disturbing magnetic field of the first embodiment when the generation of the disturbing magnetic field is stopped. It is configured to have a function of opening (in a short time). This magnetic field generator 50B can increase the output of the disturbing magnetic field, change the resonance frequency, generate a magnetic field whose frequency changes, and use a magnetic head for skimming to generate magnetic data. Can be reliably prevented with high accuracy, erroneous detection of the magnetic field by the pre-head 39 can be prevented, and opening / closing control of the shutter 38 can be performed with good responsiveness. Even when the card is inserted, it is possible to suppress the occurrence of an event such that the card collides with (should collide with) the shutter 38.

[First Embodiment of Magnetic Field Generator]
First, the magnetic field generator according to the first embodiment will be described.
FIG. 5 is a circuit diagram showing a magnetic field generator, a drive control circuit, and a frequency changer of the magnetic field generator according to the first embodiment of the present invention.

  The magnetic field generator 50A of FIG. 5 basically includes a drive power supply unit 521 that supplies a drive power supply voltage VCC as a resonance unit 511 drive control circuit 52A that constitutes the magnetic field generation unit 51A, a reference potential unit 522, and a resonance drive unit 523. And a switching unit 531 of the frequency changing unit 53A. The resonance unit 511 forms a resonance circuit by connecting one or a plurality of capacitors of the inductor L51 and a plurality of (here, two or more) capacitors in parallel. Based on the control of the control unit 40, the switching unit 531 of the frequency changing unit 53A switches the parallel connection state of the inductor L51 forming the resonance circuit and one or a plurality of capacitors C51, C52 (and C53...). (Change) and has a function of changing (switching) the resonance frequency.

  In the present embodiment, the drive power supply voltage (hereinafter also referred to as drive voltage) VCC supplied by the drive power supply unit 521 is set to 24V or 20V. The drive power supply unit 521 supplies the drive voltage VCC to the resonance unit 511 through the connection node ND51 connected to the supply source SVCC of the drive voltage VCC. In the drive power supply unit 521, a backflow prevention diode D51 is connected between the connection node ND51 and the power input node (first node ND52) of the resonance unit 511. The diode D51 is connected in a forward direction from the connection node ND51 toward the first node ND52 of the resonance unit 511. That is, the diode D51 has an anode connected to the connection node ND51 and a cathode connected to the first node ND52 of the resonance unit 511.

  The reference potential unit 522 is set to the reference potential VSS. In the present embodiment, the reference potential is the ground potential GND.

  The resonance unit 511 includes a resonance circuit in which an inductor L51 and a capacitor C51 or C52 connected by the switching unit 531 of the frequency changing unit 53A are connected in parallel between the first node ND52 and the second node ND53. It is configured. The resonance unit 511 receives the drive voltage VCC at the first node ND52, resonates in a state where the second node ND53 is electrically connected to the reference potential unit 522, and generates a magnetic field according to the current flowing through the inductor L51. To do. In other words, the resonating unit 511 is configured to generate a disturbing magnetic field for the skimming magnetic head to prevent unauthorized acquisition of magnetic data. Further, the resonance unit 511 has a function of changing the resonance frequency, for example, periodically (or randomly) by the switching operation by the frequency changing unit 53, and the resonance unit 511 has a plurality of (two in the example of FIG. 5) resonance frequencies. A corresponding disturbing magnetic field can be generated. As a result, it is possible not only to increase the output of the disturbing magnetic field, but also to change the resonance frequency, to generate a magnetic field whose frequency changes, and to illegally store magnetic data using the skimming magnetic head. Can be reliably prevented with high accuracy.

  In the present embodiment, as shown as an example in FIG. 5, the resonance circuit includes an LC parallel resonance in which an inductor L51 and a capacitor C51 or a capacitor C52 are connected in parallel between a first node ND52 and a second node ND53. It is constituted by a circuit. One end of the coil that is the inductor L51 is connected to the first node ND52, and the other end of the coil is connected to the second node ND53. One electrode (terminal) of capacitor C51 and / or capacitor C52 is connected to first node ND52, and the other electrode (terminal) is connected to second node ND53. The first node ND52 is connected to the supply line of the power supply voltage VCC of the drive power supply unit 521. The second node ND53 is selectively connected to the reference potential unit 522 via the high power drive switching element DSW51 of the resonance drive unit 523.

  In the LC parallel resonance circuit, the currents of the LC cancel each other, and under the control of the control unit 40, the impedance looks infinite from the outside at the resonance frequency held or set by the frequency changing unit 53A. At this time, the energy stored as an electric field inside the capacitor C51 (C52) and the energy stored as a magnetic field inside the coil which is the inductor L51 move to each other inside the system. In the present embodiment, the resonance unit 511 is controlled so as to periodically resonate with the pulsed control signal CTL through the resonance driving unit 523. The pulse-like control signal CLT may be controlled so as to resonate aperiodically, or may be controlled so as to mix periodic and aperiodic.

  The resonance unit 511 is controlled such that resonance is induced and a disturbing magnetic field is generated by switching a connection state and a non-connection state between the second node ND53 and the reference potential unit 522 through the resonance driving unit 523. . The resonance unit 511 functions as a disturbing magnetic field after the card MC is inserted into the card insertion slot 311 through the resonance driving unit 523 and the card width (detection) sensor 371 detects the card MC. Control is performed so as not to generate a disturbing magnetic field for a time longer than the above-described period until the magnetic field that cannot be held or the generated magnetic field disappears (magnetic field generation stop control). The controller 40 determines whether or not magnetism is detected by the pre-head 39 during a predetermined period in which the generation of the disturbing magnetic field is stopped. The period here means that after a resonant action is induced and a magnetic field is generated, the magnetic field is attenuated as the resonance energy is attenuated. Is a period during which can be induced.

  The resonance driving unit 523 induces resonance by switching the connection state and the non-connection state between the second node ND53 of the resonance unit 511 and the reference potential unit 522 in accordance with the control signal CTL from the control unit 40. Control to generate disturbing magnetic field. The resonance driving unit 523 generates a magnetic field generated when the second node ND53 of the resonance unit 511 and the reference potential unit 522 are periodically or / and aperiodically switched to a non-connected state according to the control signal CTL. Is controlled so as not to generate a disturbing magnetic field for a time longer than the above-described period, at which the function as a disturbing magnetic field cannot be maintained.

  The resonance drive unit 523 of the present embodiment includes a high power drive switching element DSW 51 formed by a transistor such as a bipolar transistor. The drive switching element DSW51 is connected between the second node ND53 of the resonance unit 511 and the reference potential unit 522, and is switched between a conduction state and a non-conduction state according to the control signal CTL. The connection state and non-connection state of the node ND53 and the reference potential portion 522 are switched.

  Resonance drive unit 523, when receiving control signal CTL at an active high level, for example, drives drive switching element DSW51 to a conductive state. When the resonance driving unit 523 receives the control signal CTL at an inactive low level, the resonance driving unit 523 drives the drive switching element DSW 51 to a non-conduction state.

[Configuration example of frequency changing unit]
Here, a configuration example of the frequency changing unit 53A capable of changing the resonance frequency in the LC parallel resonance circuit of the resonance unit 511 will be described. In the following configuration example, basically, a plurality (two or three in this example) of capacitors having the same or different resonance capacitance (capacitance) are arranged in the resonance circuit.

  The frequency changing unit 53A is a switching unit 531 having a connection switching mechanism such as a relay (and a switch), an SSR (semiconductor relay), a thyristor, a triac, and a transistor, and is connected to a resonance capacitor connected in parallel with the inductor L51. By switching, the resonance frequency can be changed. Even if the resonance capacitors have the same capacitance, the resonance frequency can be changed by changing the number of capacitors to be connected.

Incidentally, the resonance frequency fr of the LC parallel resonance circuit is given by 1 / (2π√LvCv). Here, √LvCv means (LvCv) ^1/2 . Lv represents the reactance of the inductor L, and Cv represents the capacitance of the capacitor C. For example, when the capacitance Cv1 of the capacitor C51 and the capacitance Cv2 of the capacitor C52 are set to different values, by connecting one of the capacitor C51 and the capacitor C52 as a resonance capacitor connected in parallel with the inductor L51. The resonance frequency fr can be changed. In this case, the first resonance frequency fr1 is 1 / (2π√LvCv1), and the second resonance frequency fr2 is 1 / (2π√LvCv2).

  In this example, the resonance frequency fr can be changed even if the two capacitors C51 and C52 are both connected in parallel to the inductor L51. In this case, the first resonance frequency fr1 is 1 / (2π√LvCv1), and the second resonance frequency fr2 is 1 / (2π√Lv (Cv1 + Cv2)).

  When the capacitance Cv1 of the capacitor C51 and the capacitance Cv2 (= Cv1) of the capacitor C52 are set to the same value, either one of the capacitor C51 or the capacitor C52 is used as a resonance capacitor connected in parallel with the inductor L51. The resonance frequency fr can be changed by switching between the case of connection and the case of connection of the two capacitors C51 and C52. In the case of the example of FIG. 5, the first resonance frequency fr1 is 1 / (2π√LvCv1), and the second resonance frequency fr2 is 1 / (2π√Lv · 2Cv1). In this case, the combined capacitance is 2Cv1 by (Cv1 + Cv2 (= Cv1)).

[First configuration example of frequency changing unit]
A first configuration example of the frequency changing unit will be described with reference to FIG. FIG. 6 is a circuit diagram illustrating a first configuration example of the frequency changing unit according to the present embodiment.

  In FIG. 6, the resonance circuit of the resonance unit 511 is basically configured by an LC parallel resonance circuit in which an inductor L51 and a capacitor C51 are connected in parallel between a first node ND52 and a second node ND53. Yes. Further, the resonance circuit of the resonance unit 511 includes a capacitor C52 connected in parallel to the capacitor C51 by the switching operation of the switching unit 531A of the frequency changing unit 53A.

  6 includes a relay switch 5311 including a relay coil L531, an on / off switch SW531, and a connection switching switch SW532.

  One end of relay coil L531 is connected to supply source VCC of power supply voltage VCC, the other end is connected to one end of on / off switch SW531, and the other end of on / off switch SW531 is at reference potential VSS (here, ground potential GND). It is connected to a certain reference potential portion 522. The on / off switch SW531 is turned on (conductive state) when receiving the frequency switching control signal SFS supplied from the control unit 40 at an active high level, for example. When the on / off switch SW531 is turned on, the other end of the relay coil L531 is connected to the reference potential section 522, and a current flows through the relay coil L531. When the on / off switch SW531 receives the frequency switching control signal SFS supplied from the control unit 40 at an inactive low level, the on / off switch SW531 enters an off state (non-conducting state). When the on / off switch SW531 is turned off, the other end of the relay coil L531 is electrically disconnected from the reference potential section 522, and no current flows through the relay coil L531. The on / off switch SW531 is configured by, for example, an npn-type bipolar transistor or a MOS transistor which is an n-channel field effect transistor (FET).

  The frequency switching control signal SFS by the control unit 40 is switched so that the active high level and the inactive low level are alternately switched in a predetermined cycle (time interval), for example, every several tens of seconds or every several minutes. Supplied. This is because it is extremely difficult to read the data of the card MC by the skimming device by generating a disturbing magnetic field whose frequency changes at an appropriate timing.

  The connection switching switch SW532 includes a fixed contact T1 to which the contact piece CT1 is connected, a fixed contact T2 to which the contact piece CT2 is connected, a pair of first operating contacts T3 and T4, and a pair of second operating contacts. T5 and T6. The fixed contact T1 is connected to the first node ND52 of the resonance unit 511, and the fixed contact T2 is connected to the second node ND53 of the resonance unit 511. The first operating contacts T3 and T4 forming a pair are provided so as to be connected to nowhere and have high impedance in a floating state (floating state). A capacitor C52 is connected between the second working contact T5 and the second working contact T6, which form a pair.

  The contact piece CT1 connected to the fixed contact T1 and the contact piece CT2 connected to the fixed contact T2 are connected to the first operating contact T3 when no current flows through the relay coil L531, The contact piece CT2 is connected to the first operating contact T4. In this case, the capacitor C52 is not connected to the capacitor C51 of the resonance unit 511. The resonance frequency fr of the resonance circuit at this time is the first resonance frequency fr and is 1 / (2π√LvCv1).

  When the current flows through the relay coil L531, the contact piece CT1 connected to the fixed contact T1 and the contact piece CT2 connected to the fixed contact T2 are connected to the second operating contact T5. The contact piece CT2 is connected to the second operating contact T6. Thereby, the first node 52, the fixed contact T1, the contact piece CT1, the operation contact T5, the capacitor C52, the operation contact T6, the contact piece CT2, the fixed contact T2, and the second node ND53 are electrically connected. In this case, the capacitor C52 is connected in parallel to the capacitor C51 of the resonance unit 511. The resonance frequency fr of the resonance circuit at this time is the second resonance frequency fr2, which is 1 / (2π√Lv (Cv1 + Cv2)).

[Second Configuration Example of Frequency Changing Unit]
A second configuration example of the frequency changing unit will be described with reference to FIG. FIG. 7 is a circuit diagram illustrating a second configuration example of the frequency changing unit according to the present embodiment.

  In the example of FIG. 7 as well, the resonance circuit of the resonance unit 511 is basically an LC parallel resonance circuit in which an inductor L51 and a capacitor C51 are connected in parallel between the first node ND52 and the second node ND53. It is configured. Further, the resonance circuit of the resonance unit 511 includes a capacitor C52 connected in parallel to the capacitor C51 by the switching operation of the switching unit 531B of the frequency changing unit 53B.

  7 includes a thyristor (Tyristor or triac) 5312 and a thyristor (or triac) control circuit 5313. The frequency changing unit 53B shown in FIG.

  The thyristor 5312 is a three-terminal semiconductor rectifier that can conduct between the anode (A) and the cathode (K) by flowing a gate current from the gate (G) to the cathode (K). It is also called SCR (Silicon Controlled Rectifier). A thyristor and a triac are both rectifier elements for power control. A thyristor is a unidirectional control element, whereas a triac is a bidirectional control element. Both elements are applicable to the frequency changing unit 53B.

  In the frequency changing unit 53B, one end of the capacitor C52 is connected to the first node ND52 of the resonance circuit of the resonance unit 511, the other end is connected to one end of the thyristor 5312, and the other end of the thyristor 5312 is the resonance circuit of the resonance unit 511. Connected to the second node ND53.

  When the thyristor control circuit 5313 receives the frequency switching control signal SFS supplied from the control unit 40 at an active high level, for example, the thyristor control circuit 5313 controls the thyristor 5312 to be in an on state (conducting state) by the control signal S5313. In this case, the capacitor C52 is connected in parallel to the capacitor C51 of the resonance unit 511. The resonance frequency fr of the resonance circuit at this time is the second resonance frequency fr2, which is 1 / (2π√Lv (Cv1 + Cv2)).

  When the thyristor control circuit 5313 receives the frequency switching control signal SFS supplied from the control unit 40 at an inactive low level, the thyristor control circuit 5313 controls the thyristor 5312 to be turned off (non-conducting state) by the control signal S5313. In this case, the capacitor C52 is not connected to the capacitor C51 of the resonance unit 511. The resonance frequency fr of the resonance circuit at this time is the first resonance frequency fr, which is 1 / (2π√LvCv1).

  As described above, the frequency switching control signal SFS by the control unit 40 is alternately generated in a cycle (time interval) in which active high level and inactive low level are set in advance, for example, in units of several tens of seconds or in units of several minutes. Supplied to switch. This is because it is very difficult to read the magnetic data of the card MC by the skimming device by generating a disturbing magnetic field whose frequency changes at an appropriate timing.

[Third configuration example of frequency changing unit]
A third configuration example of the frequency changing unit will be described with reference to FIG.
FIG. 8 is a circuit diagram showing a third configuration example of the frequency changing unit according to the present embodiment.

  Also in the example of FIG. 8, the resonance circuit of the resonance unit 511 is basically an LC parallel resonance circuit in which an inductor L51 and a capacitor C51 are connected in parallel between the first node ND52 and the second node ND53. It is configured. Further, the resonance circuit of the resonance unit 511 includes a capacitor C52 connected in parallel to the capacitor C51 by the switching operation of the switching unit 531C of the frequency changing unit 53C.

  8 includes a SSR (Solid State Relay) 5314 and an SSR (semiconductor relay) control circuit 5315. The switching unit 531C of the frequency changing unit 53C in FIG.

  The SSR 5314 includes a light emitting element such as an LED 53141 and a photoelectric element such as a photodiode 53142. The LED 53141 emits light, and the photodiode 53142 that has received the emitted light conducts.

  In the frequency changing unit 53C, one end of the capacitor C52 is connected to the first node ND52 of the resonance circuit of the resonance unit 511, the other end is connected to the anode side of the photodiode 53142 which is one end of the SSR 5314, and the other end of the SSR 5314 is connected. The cathode of a certain photodiode 53142 is connected to the second node ND53 of the resonance circuit of the resonance unit 511.

  When the SSR control circuit 5315 receives the frequency switching control signal SFS supplied from the control unit 40 at, for example, an active high level, the SSR control circuit 5315 controls the LED 53141 of the SSR 5314 to be in a light emitting state by the control signal S5315. Thus, the photodiode 53142 that has received the emitted light is turned on. In this case, the capacitor C52 is connected in parallel to the capacitor C51 of the resonance unit 511. The resonance frequency fr of the resonance circuit at this time is the second resonance frequency fr2, which is 1 / (2π√Lv (Cv1 + Cv2)).

  When the SSR control circuit 5315 receives the frequency switching control signal SFS supplied from the control unit 40 at an inactive low level, the SSR control circuit 5315 controls the SSR 5314 to be in a non-light emitting state (non-conducting state) by the control signal S5315. Accordingly, the photodiode 53142 is turned off. In this case, the capacitor C52 is not connected to the capacitor C51 of the resonance unit 511. The resonance frequency fr of the resonance circuit at this time is the first resonance frequency fr, which is 1 / (2π√LvCv1).

  As described above, the frequency switching control signal SFS by the control unit 40 is alternately generated in a cycle (time interval) in which active high level and inactive low level are set in advance, for example, in units of several tens of seconds or in units of several minutes. Supplied to switch. This is because it is extremely difficult to read the data of the card MC by the skimming device by generating a disturbing magnetic field whose frequency changes at an appropriate timing.

[Fourth configuration example of frequency changing unit]
A fourth configuration example of the frequency changing unit will be described with reference to FIG. FIG. 9 is a circuit diagram illustrating a fourth configuration example of the frequency changing unit according to the present embodiment.

  In the example of FIG. 9 as well, the resonance circuit of the resonance unit 511 is basically an LC parallel resonance circuit in which an inductor L51 and a capacitor C51 are connected in parallel between the first node ND52 and the second node ND53. It is configured. In the example of FIG. 9, the resonance circuit of the resonance unit 511 includes a capacitor C52 and a capacitor C53 connected in parallel to the capacitor C51 by the switching operation of the switching unit 531D of the frequency changing unit 53D.

  The frequency changing unit 53D in FIG. 9 is different from the frequency changing unit 53A in FIG. 6 in that the number of capacitors C53 connected in parallel to the capacitor C51 increases, and this capacitor C53 forms a pair of connection switching switches SW532. 1 is connected between the operation contact T3 and the operation contact T4.

  The contact piece CT1 connected to the fixed contact T1 and the contact piece CT2 connected to the fixed contact T2 are connected to the first operating contact T3 when no current flows through the relay coil L531, The contact piece CT2 is connected to the first operating contact T4. Thereby, the first node 52, the fixed contact T1, the contact piece CT1, the operation contact T3, the capacitor C53, the operation contact T4, the contact piece CT2, the fixed contact T2, and the second node ND53 are electrically connected. In this case, the capacitor C53 is connected in parallel to the capacitor C51 of the resonance unit 511. The first resonance frequency fr of the resonance circuit at this time is 1 / (2π√Lv (Cv1 + Cv3), where Cv3 indicates the capacitance of the capacitor C53.

  When the current flows through the relay coil L531, the contact piece CT1 connected to the fixed contact T1 and the contact piece CT2 connected to the fixed contact T2 are connected to the second operating contact T5. The contact piece CT2 is connected to the second operating contact T6. Thereby, the first node 52, the fixed contact T1, the contact piece CT1, the operation contact T5, the capacitor C52, the operation contact T6, the contact piece CT2, the fixed contact T2, and the second node ND53 are electrically connected. In this case, the capacitor C52 is connected in parallel to the capacitor C51 of the resonance unit 511. The resonance frequency fr of the resonance circuit at this time is the second resonance frequency fr2, which is 1 / (2π√Lv (Cv1 + Cv2)).

  Next, the operation of the magnetic field generator 50A according to the first embodiment will be described with reference to FIG. FIG. 10 is a waveform diagram for explaining the operation of the magnetic field generator according to the first embodiment. FIG. 10 shows a waveform of a simulation result when the magnetic field generator 50A of FIG. 5 is mounted on the magnetic card reader 10 of FIG. 10A is a diagram showing the control signal CTL, FIG. 10B is a diagram showing the disturbing magnetic field DMG, and FIG. 10C is a diagram showing the frequency switching control signal SFS.

  First, as shown in FIGS. 10A and 10B, the control signal CTL is sent from the control unit 40 to the drive control circuit in the magnetic field generator 50A so as to generate the disturbing magnetic field in a state where the disturbing magnetic field is not generated. The resonance drive unit 523 of 52A is supplied. In this case, the control signal CTL is supplied at an active high level (H). When the resonance drive unit 523 receives the control signal CTL at an active high level, the drive switching element DSW 51 is driven to a conductive state.

  Further, for example, the frequency switching control signal SFS is supplied from the control unit 40 to the on / off switch SW531 of the frequency changing unit 53A at an inactive low level as shown by a solid line in FIG. Accordingly, the on / off switch SW531 is turned off (non-conducting state). When the on / off switch SW531 is turned off, the other end of the relay coil L531 is electrically disconnected from the reference potential section 522, and no current flows through the relay coil L531. Therefore, the capacitor C52 is not connected in parallel to the capacitor C51. In this case, the resonance frequency fr of the resonance circuit is the first resonance frequency fr, which is 1 / (2π√LvCv1).

  Then, at a predetermined cycle (time interval), the frequency switching control signal SFS from the control unit 40 to the on / off switch SW531 of the frequency changing unit 53A is an active high level as shown by a broken line in FIG. Supplied in. Accordingly, the on / off switch SW531 is turned on (conductive state). When the on / off switch SW531 is turned on, the other end of the relay coil L531 is electrically connected from the reference potential section 522, and a current flows through the relay coil L531. Therefore, the capacitor C52 is connected in parallel to the capacitor C51. In this case, the resonance frequency fr of the resonance circuit is the second resonance frequency fr, which is 1 / (2π√Lv (Cv1 + Cv2)).

  Generation of the disturbing magnetic field by the above two resonance frequencies is performed periodically (or randomly).

  In the resonance portion 511, the second node ND53 is electrically connected to the reference potential portion 522. In the resonance unit 511, the drive voltage VCC is supplied from the drive power supply unit 521 to the first node ND52. That is, the resonance unit 511 is switched to the connection state between the second node ND53 and the reference potential unit 522 through the resonance driving unit 523, thereby inducing a resonance function and increasing a current flowing through the coil (inductor) L51. , Controlled to generate a disturbing magnetic field.

  Here, the control signal CTL is switched to the inactive low level (L) and supplied to the resonance driving unit 523. When the resonance drive unit 523 receives the control signal CTL at an inactive low level, the drive switching element DSW 51 is driven to a non-conduction state.

  At this time, the second node ND53 of the resonance unit 511 is electrically disconnected from the reference potential unit 522, but the resonance unit 511 attenuates the current IL of the coil (inductor) L51 by the induced resonance energy. Along with this, the generation of the disturbing magnetic field is attenuated but continues to occur.

  Here, the control unit 40 supplies, for example, a pulse-shaped control signal CTL to the resonance driving unit 523 to induce a resonance action in the resonance unit 511 and generate a magnetic field. Attenuates. However, the control unit 40 has a constant period and / or non-period from the previous output (supply) so that resonance can be induced while the decaying magnetic field retains the function as a disturbing magnetic field. The control signal CTL is supplied to the resonance driving unit 523 at an active high level (H) at (random).

  That is, as described above, as shown in FIGS. 10A and 10B, the control signal CTL is activated from the control unit 40 to the resonance drive unit 523 of the drive control circuit 52A so as to generate the disturbing magnetic field again. At a high level (H). When the resonance drive unit 523 receives the control signal CTL at an active high level, the drive switching element DSW 51 is driven to a conductive state.

  Accordingly, in the resonance unit 511, the second node ND53 is electrically connected to the reference potential unit 522. In the resonance unit 511, the drive voltage VCC is supplied from the drive power supply unit 521 to the first node ND52. That is, the resonance unit 511 is switched to the connection state between the second node ND53 and the reference potential unit 522 through the resonance driving unit 523, so that the resonance function is induced again and the current flowing through the coil (inductor) L51 increases. And controlled to generate a disturbing magnetic field.

  Here, the pulse-like control signal CTL is switched to the inactive low level (L) and supplied to the resonance driving unit 523. When the resonance drive unit 523 receives the control signal CTL at an inactive low level, the drive switching element DSW 51 is driven to a non-conduction state.

  At this time, the second node ND53 of the resonance unit 511 is electrically disconnected from the reference potential unit 522, but the resonance unit 511 flows while the current of the coil (inductor) L51 is attenuated by the induced resonance energy. As a result, the generation of the disturbing magnetic field continues to be attenuated.

  The operation including the switching of the resonance frequency is repeatedly performed during the period in which the disturbing magnetic field is generated.

  As described above, in the card reader 10 equipped with the magnetic field generator 50A of the first embodiment, a magnetic field is generated by generating a disturbing magnetic field for the skimming magnetic head device improperly attached to the card insertion slot 311. Data can be prevented from being read. Further, by generating a disturbing magnetic field whose frequency changes at an appropriate timing, it is possible to make it extremely difficult to read the data of the card MC by the skimming device.

  By the way, in the card reader 10 equipped with the magnetic field generator 50A of the first embodiment, when the disturbing magnetic field is generated by the resonance unit (resonance circuit) 511, a card detection sensor (card width sensor in this example). When a card is detected at 371, it is necessary to detect the magnetic field by the pre-head 39, so it is necessary to stop the generation of the disturbing magnetic field. Therefore, in the card reader 10 equipped with the magnetic field generator 50A, the control unit 40 periodically or / and aperiodically stops the generation of the disturbing magnetic field triggered by the card detection sensor 371 detecting the card. The output of the control signal CTL to the resonance drive unit 523 of the drive control circuit 52A is stopped.

  Thus, in the card reader 10 equipped with the magnetic field generation device 50A, the output of the control signal CTL for generating the disturbing magnetic field is stopped when the card detection sensor (card width sensor) 371 detects the card. At this time, the magnetic field tends to remain due to resonance for several ms. As described above, magnetic detection is performed by the pre-head 39. However, if the magnetic field remains, there is a possibility that it cannot be distinguished whether the magnetic data of the card or the remaining disturbance magnetic field. Therefore, in the card reader 10 equipped with the magnetic field generation device 50A, this estimated time is assumed assuming that the generated magnetic field cannot maintain the function as a disturbing magnetic field or the time until the generated magnetic field disappears. Control is performed so that the shutter 38 cannot be opened until the time has elapsed.

  For example, in the card reader 10, the arrangement of the pre-head 39 and the shutter 38 in the card conveying direction is arranged so as to have an interval (distance) until the resonance energy is attenuated until it is not affected by the magnetic head. Yes. Further, it may be set to an output that can attenuate the resonance energy. Further, a load may be applied to the card transport path 32 when transporting the card MC, and the time to reach the shutter 38 may be saved.

  As described above, in the magnetic field generator 50A according to the first embodiment, the coil L51 and the capacitor C51, which are inductors, are basically connected to the capacitors C52 and C53 periodically (or randomly). The LC parallel resonant circuit is formed and a large magnetic field is continuously generated by the LC parallel resonant circuit for a predetermined period due to the retention characteristic of the resonance energy, so that the output of the disturbing magnetic field is increased as a result, The resonance frequency can be changed, a magnetic field with a changing frequency can be generated, and unauthorized acquisition of magnetic data can be reliably prevented with high accuracy. That is, in order for a fraudster to read the magnetic data of the card MC, a skimming magnetic head (and a magnetic reading circuit) is provided in the card insertion slot 311 of the card reader 10 on the outside of the front panel 20 of the host device. Even if the device 60 is attached, it is possible to generate a strong magnetic field, increase the output of the disturbing magnetic field, change the resonance frequency, and generate a magnetic field with a changing frequency. In addition, illegal acquisition of magnetic data using the skimming magnetic head can be reliably prevented with high accuracy.

[Second Embodiment of Magnetic Field Generator]
Next, a magnetic field generator according to the second embodiment will be described.
FIG. 11 is a circuit diagram showing a magnetic field generation unit, a drive control circuit, and a frequency change unit of a magnetic field generation apparatus according to the second embodiment of the present invention. FIG. 12 is a circuit diagram more specifically showing the main part of the drive control circuit according to the second embodiment of the present invention, focusing on the operation of the magnetic field generator according to the second embodiment when the magnetic field generation is stopped. It is a figure for demonstrating. Since the frequency changing unit is the same as the configuration and function described in association with FIGS. 5 to 9 in the first embodiment, the description thereof is omitted here.

  The magnetic field generator 50B according to the second embodiment is different from the magnetic field generator 50A according to the first embodiment described above as follows. The magnetic field generator 50B according to the second embodiment releases the resonance energy in the LC parallel resonant circuit that generates the disturbing magnetic field of the first embodiment quickly (in a short time) when the generation of the disturbing magnetic field is stopped. It is configured to have a function to The reason for adopting this configuration will be described.

  As described above, in the card reader 10 equipped with the magnetic field generation device 50A of the first embodiment, the detection of the card MC by the card detection sensor (card width sensor in this example) 371 is used as a trigger. In order to stop the generation, the control unit 40 is configured to stop the output of the periodic or / and aperiodic control signal CTL to the resonance drive unit 523 of the drive control circuit 52A. Thus, in the card reader 10 equipped with the magnetic field generator 50A of the first embodiment, a control signal for generating a disturbing magnetic field triggered by the card detection sensor (card width sensor) 371 detecting the card MC. Although the output of the CTL is stopped, the magnetic field tends to remain due to resonance for several ms. As described above, magnetic detection is performed by the pre-head 39. However, if the magnetic field remains, there is a possibility that it cannot be distinguished whether the magnetic data of the card MC or the remaining disturbing magnetic field is left. Therefore, in the card reader 10 on which the magnetic field generator 50A of the first embodiment is mounted, a time until the generated magnetic field cannot maintain the function as a disturbing magnetic field or the time until the generated magnetic field disappears is assumed. Thus, the shutter 38 is controlled not to be opened until the estimated time has elapsed.

  However, when this control method is adopted, the time until the shutter 38 opens tends to be long. Therefore, when a card is inserted quickly, there is a possibility that an event such as the card colliding (colliding) with the shutter 38 may occur.

  Therefore, in the magnetic field generator 50B of the second embodiment, the first switching element DSW52 for discharge is connected to the first node ND52 of the resonance unit 511B, and the resonance energy emission path (discharge path, escape path). Is secured. Here, in this embodiment, the first switching element DSW 52 can be formed by a transistor capable of switching with high power, for example, formed by a transistor such as a bipolar transistor, but is formed by other transistors, for example, FETs. May be.

  Further, in the magnetic field generator 50B of the second embodiment, the first node of the resonance unit 511B of the power supply voltage VCC when the disturbing magnetic field generation is stopped on the supply line to the resonance unit 511B of the power supply voltage VCC of the drive power supply unit 521B. A second switching element SW51 for stopping supply to the ND 52 is connected.

  As will be described later, when the magnetic field generator 50B of the second embodiment stops the resonance of the resonance unit 511B and releases the resonance energy, the second switching element SW51 (for example, the transistor TR2) of the drive power supply unit 521B is released. ) Is turned off (OFF state) and the supply of the drive voltage VCC is stopped, and then the first switching element DSW52 for discharge (for example, the transistor TR1) is turned on (ON state) to release the resonance energy. Configured to do. The drive control circuit 52B according to the second embodiment switches the first switching element DSW52 for discharging to the non-conducting state and then turns the second switching element SW51 into the conducting state when starting (resuming) the magnetic field generation. Configured to switch to

  Hereinafter, a specific configuration of the magnetic field generation device 50B according to the second embodiment will be described in detail with a focus on portions added to the configuration of FIG. In the magnetic field generator 50B, a discharge drive unit 524 is added to the drive control circuit 52B, and the configuration of the drive power supply unit 521B is different from that of the drive control circuit 52A of the first embodiment.

  Discharge drive unit 524 is connected between first node ND52 of resonance unit 511B and a discharge potential unit, for example, reference potential unit 522, and is in a conductive state or a non-conductive state according to first magnetic field generation stop signal STP1. Including the transistor TR1 as the first switching element DSW52 corresponding to the high power that switches between the connection state and the non-connection state between the first node ND52 of the resonance unit 511B and the reference potential unit 522 that is the discharge potential unit. It consists of The discharge driver 524 connects the transistor TR1 as the first switching element DSW52 for discharge to the first node ND52 of the resonance unit 511B to form a resonance energy discharge path (discharge path).

  As shown in FIG. 12, the discharge driving unit 524 of the present embodiment includes a first switching element DSW52 for discharging between a first node ND52 of the resonance unit 511B and a discharging potential unit, for example, a reference potential unit 522. The transistor TR1 is connected. The transistor TR1 is formed of, for example, an npn-type bipolar transistor as the first switching element DSW52 corresponding to high power.

  The transistor TR1 constituting the first switching element DSW52 is connected between the first node ND52 of the resonance unit 511B and the reference potential unit 522, and is turned on or off according to the first magnetic field generation stop signal STP1. The state is switched, and the connection state and the non-connection state between the first node ND52 of the resonance unit 511B and the reference potential unit 522 are switched. In the transistor TR1, the collector (C) is connected to the first node ND52 of the resonance unit 511B, the emitter (E) is connected to the reference potential unit 522, and the base (B) is supplied with the first magnetic field generation stop signal STP1. Connected to the line.

  When receiving the first magnetic field generation stop signal STP1 at an active high level, for example, the discharge driving unit 524 drives the transistor TR1 that is the first switching element DSW52 to a conductive state. When receiving the first magnetic field generation stop signal STP1 at an inactive low level, the discharge driver 524 drives the transistor TR1 that is the first switching element DSW52 to a non-conduction state.

  The drive power supply unit 521B is connected between the supply source VCC of the drive voltage VCC and the first node ND52 of the resonance unit 511B, and is switched between a conduction state and a non-conduction state according to the second magnetic field generation stop signal STP2. The transistor TR2 is configured as a second switching element SW51 that switches between a connection state and a non-connection state between the drive voltage supply source VCC and the first node ND52 of the resonance unit 511B. In the drive power supply unit 521B of the second embodiment, the supply of the power supply voltage VCC to the first node ND52 of the resonance unit 511B is stopped by the second switching element SW51 when the generation of the disturbing magnetic field is stopped.

  In the driving power supply unit 521B of the present embodiment, as shown in FIG. 12, a transistor TR2 as the second switching element SW51 is connected between the supply source VCCC of the driving voltage VCC and the first node ND52 of the resonance unit 511B. Has been. Transistor TR2 is formed of, for example, an npn type bipolar tunnel.

  The transistor TR2 constituting the second switching element SW51 is connected between the connection node ND51 and the anode of the diode D51 (and the first node ND52 of the resonance unit 511B), and is connected to the second magnetic field generation stop signal STP2. Accordingly, the conduction state and the non-conduction state are switched, and the connection state and the non-connection state between the connection node ND51 and the first node ND52 of the resonance unit 511B are switched. In the transistor TR2, the collector (C) is connected to the connection node ND51 (further, the source SVCC of the drive voltage VCC), the emitter (E) is connected to the anode of the diode D51, and the base (B) is stopped from generating the second magnetic field. It is connected to the supply line of signal STP2.

  When the drive power supply unit 521B receives the second magnetic field generation stop signal STP2 at, for example, an active low level, the drive power supply unit 521B drives the transistor TR2 that is the second switching element SW51 to a non-conduction state, thereby generating the second magnetic field generation stop signal STP2. Is received at an inactive high level, the transistor TR2 as the second switching element SW51 is driven to a conductive state.

  In the control unit 40, the first magnetic field generation stop signal STP1 and the second magnetic field generation stop signal STP2 supplied to the drive control circuit 52B of the second embodiment are basically set at complementary levels. Generated. That is, basically, when the first magnetic field generation stop signal STP1 is set to a high level, the second magnetic field generation stop signal STP2 is set to a low level, and the first magnetic field generation stop signal STP1 is set to a low level. When set, the second magnetic field generation stop signal STP2 is set to a high level.

  In the present embodiment, when a magnetic field is generated, that is, when a disturbing magnetic field is generated for the skimming magnetic head, the first magnetic field generation stop signal STP1 is set to a low level, and the second magnetic field generation stop signal STP2 is set. Is set high. As a result, the transistor TR1 as the first switching element DSW52 of the discharge driver 524 is switched to the non-conductive state, and the transistor TR2 as the second switching element SW51 of the drive power supply unit 521B is switched to the conductive state.

  When the magnetic field generation is stopped, the first magnetic field generation stop signal STP1 is set to a high level, and the second magnetic field generation stop signal STP2 is set to a low level. As a result, the transistor TR1 as the first switching element DSW52 of the discharge driver 524 is switched to the conductive state, and the transistor TR2 as the second switching element SW51 of the drive power supply unit 521B is switched to the nonconductive state. In this case, in order to efficiently release (discharge) the resonance energy, the second magnetic field generation stop signal STP2 is set to a low level, and the transistor TR2 as the second switching element SW51 is switched to the non-conductive state. After that, the first magnetic field generation stop signal STP1 is switched to the high level, and the transistor TR1 as the first switching element DSW52 is switched to the conductive state.

  At the time of starting (resuming) magnetic field generation, the first magnetic field generation stop signal STP1 is set to a low level and the transistor TR1 as the first switching element DSW52 is switched to a non-conductive state in order to efficiently supply power. After that, the second magnetic field generation stop signal STP2 is switched to the high level, and the transistor TR2 as the second switching element SW51 is switched to the conductive state.

  The magnetic field generator 50B having the above configuration is arranged in the vicinity of the inner side (rear surface side) of the front panel 20 as shown in FIG. 1 as in the case of the magnetic field generator 50A of the first embodiment described above. The magnetic field generator 50B can be arranged including the entire circuit. For example, only the coil (inductor) L51 and the capacitors C51 and C52 (C53) are arranged in the vicinity of the inner side of the front panel 20, and the remaining circuit system is the other. Various modes are possible, such as being arranged on the control unit 40 side, for example.

  This magnetic field generator 50B can increase and continue the output of the disturbing magnetic field, can change the resonance frequency, can generate a magnetic field whose frequency changes, and uses a magnetic head for skimming. It is possible to reliably prevent magnetic data from being illegally acquired with high accuracy, to prevent erroneous detection of a magnetic field by the pre-head 39, and to perform opening / closing control of the shutter 38 with high responsiveness, and thus quickly. Even when a card is inserted, it is possible to suppress the occurrence of an event such that the card hits the shutter 38 (collises).

  Next, the operation of the magnetic field generator 50B according to the second embodiment will be described with reference to FIGS. FIG. 12 is a diagram for explaining mainly the operation of the magnetic field generator according to the second embodiment when the magnetic field generation is stopped. FIG. 13 is a waveform diagram for explaining the operation of the magnetic field generator according to the second embodiment. FIG. 13 shows waveforms of simulation results when the magnetic field generator 50B of FIGS. 11 and 12 is mounted on the card reader of FIG. 13A shows the control signal CTL, FIG. 13B shows the second magnetic field generation stop signal STP2, FIG. 13C shows the first magnetic field generation stop signal STP1, and FIG. (D) is a diagram showing the disturbing magnetic field DMG, and FIG. 13 (e) is a diagram showing the frequency switching control signal SFS.

  In the following, although there is an overlap with the description of the operation in the first embodiment, first, the operation for starting the normal generation of the disturbing magnetic field is described, and then the generation of the disturbing magnetic field accompanied by the resonance energy release (discharge) processing after the card detection. The stop operation will be described.

[Interference magnetic field generation operation]
When the magnetic field generation device 50B generates a magnetic field, that is, when a disturbing magnetic field is generated for the skimming magnetic head, the resonance energy is not discharged (discharged), and the drive voltage VCC is the first of the resonance unit 511B. In addition, the second node ND53 of the resonance unit 511B needs to be connected to the reference potential unit 522.

  Based on this, first, as shown by a signal waveform in FIG. 12A, the first magnetic field generation stop signal STP1 is inactive at a low level (L) so that resonance energy is not released (discharged). ) From the control unit 40 to the discharge drive unit 524 of the drive control circuit 52B. When the discharge drive unit 524 receives the first magnetic field generation stop signal STP1 at an inactive low level, the transistor TR1 that is the first switching element DSW52 is driven to a non-conduction state. As a result, resonance energy is not released (discharged) from the first node ND52 of the resonance unit 511B.

  In parallel with this, the second magnetic field generation stop signal STP2 is inactive as shown by the signal waveform in FIG. 12A so that the drive voltage VCC is supplied to the first node ND52 of the resonance unit 511B. Is supplied from the control unit 40 to the drive power supply unit 521B of the drive control circuit 52B. In the drive power supply unit 521B, when the second magnetic field generation stop signal STP2 is received at an inactive high level (H), the transistor TR1 as the second switching element SW51 is turned on (ON state). Along with the transition of the transistor TR1 to the conducting state, the driving voltage VCC from the driving power supply unit 521B is supplied to the first node ND52 of the resonance unit 511B.

  Then, for example, as shown in FIG. 13A, the control signal CTL is generated from the control unit 40 to the resonance drive unit 523 of the drive control circuit 52A so as to generate the disturbance magnetic field in a state where no (interference) magnetic field is generated. To be supplied. In this case, the control signal CTL is supplied in pulses at an active high level (H). When the resonance drive unit 523 receives the control signal CTL at an active high level, the drive switching element DSW 51 is driven to a conductive state.

  Further, referring to FIG. 6 as an example, for example, the frequency switching control signal SFS from the control unit 40 to the on / off switch SW531 of the frequency changing unit 53A is inactive as shown by a solid line in FIG. Supplied at low level. Accordingly, the on / off switch SW531 is turned off (non-conducting state). When the on / off switch SW531 is turned off, the other end of the relay coil L531 is electrically disconnected from the reference potential section 522, and no current flows through the relay coil L531. Therefore, the capacitor C52 is not connected in parallel to the capacitor C51. In this case, the resonance frequency fr of the resonance circuit is the first resonance frequency fr, which is 1 / (2π√LvCv1).

  Then, at a predetermined cycle (time interval), the frequency switching control signal SFS is applied to the active high level from the control unit 40 to the on / off switch SW531 of the frequency changing unit 53A as indicated by a broken line in FIG. Supplied in. Accordingly, the on / off switch SW531 is turned on (conductive state). When the on / off switch SW531 is turned on, the other end of the relay coil L531 is electrically connected from the reference potential section 522, and a current flows through the relay coil L531. Therefore, the capacitor C52 is connected in parallel to the capacitor C51. In this case, the resonance frequency fr of the resonance circuit is the second resonance frequency fr, which is 1 / (2π√Lv (Cv1 + Cv2)).

  Generation of the disturbing magnetic field by the above two resonance frequencies is performed periodically (or randomly).

  In the resonance unit 511B, the second node ND53 is electrically connected to the reference potential unit 522. As described above, in the resonance unit 511B, the drive voltage VCC is supplied from the drive power supply unit 521 to the first node ND52. That is, the resonance unit 511B is switched to the connection state between the second node ND53 and the reference potential unit 522 through the resonance driving unit 523, thereby inducing the resonance function and increasing the current flowing through the coil (inductor) L51. Control is performed to generate a disturbing magnetic field for the skimming magnetic head.

  Here, the control signal CTL is switched to the inactive low level (L) and supplied to the resonance driving unit 523. When the resonance drive unit 523 receives the control signal CTL at an inactive low level, the drive switching element DSW 51 is driven to a non-conduction state.

  At this time, the second node ND53 of the resonance unit 511B is electrically disconnected from the reference potential unit 522, but the resonance unit 511B flows while the current of the coil (inductor) L51 is attenuated by the induced resonance energy. As a result, the generation of the disturbing magnetic field continues to be attenuated.

  Here, the control unit 40 supplies the pulsed control signal CTL to the resonance driving unit 523, so that a resonance action is induced in the resonance unit 511B to generate a magnetic field, and then the magnetic field is attenuated along with the attenuation of the resonance energy. However, at a constant period and / or aperiodic (random) from the previous output (supply) so that resonance can be induced while this decaying magnetic field retains its function as a disturbing magnetic field. The control signal CTL is supplied to the resonance driving unit 523 at an active high level (H).

  That is, as described above, as shown in FIG. 13A, the control signal CTL is sent from the control unit 40 to the resonance drive unit 523 of the drive control circuit 52B so as to generate the disturbing magnetic field again. H). When the resonance drive unit 523 receives the control signal CTL at an active high level, the drive switching element DSW 51 is driven to a conductive state.

  Accordingly, the second node ND53 is electrically connected to the reference potential unit 522 in the resonance unit 511B. In the resonance unit 511, the drive voltage VCC is supplied from the drive power supply unit 521 to the first node ND52. That is, the resonance unit 511B is switched to the connection state between the second node ND53 and the reference potential unit 522 through the resonance driving unit 523, so that the resonance function is induced again and the current flowing through the coil (inductor) L51 increases. And controlled to generate a disturbing magnetic field.

  Here, the control signal CTL is switched at an inactive low level (L) and is supplied to the resonance driving unit 523. When the resonance drive unit 523 receives the control signal CTL at an inactive low level, the drive switching element DSW 51 is driven to a non-conduction state.

  At this time, the second node ND53 of the resonance unit 511B is electrically disconnected from the reference potential unit 522, but the resonance unit 511B flows while the current of the coil (inductor) L51 is attenuated by the induced resonance energy. As a result, the generation of the disturbing magnetic field continues to be attenuated.

  The operation including the switching of the resonance frequency is repeatedly performed during the period in which the disturbing magnetic field is generated.

  Thus, in the card reader 10 equipped with the magnetic field generator 50B of the second embodiment, a disturbing magnetic field is applied to the skimming magnetic head (including the reading circuit) device illegally attached to the card insertion slot 311. By generating the magnetic data, reading of the magnetic data can be prevented. Further, by generating a disturbing magnetic field whose frequency changes at an appropriate timing, it is possible to make it extremely difficult to read the data of the card MC by the skimming device.

[Interference magnetic field generation stop operation]
Next, the disturbing magnetic field generation stopping operation accompanied by the resonance energy release (discharge) processing after card detection by the card detection sensor (card width sensor in this example) 371 will be described.
When the control unit 40 receives a signal indicating that the card detection sensor 371 has detected a card, the control unit 40 releases (discharges) resonance energy, and generates a disturbing magnetic field that is likely to remain. Drive control is performed so as to quickly disappear. In this case, the first node ND52 of the resonance unit 511B is electrically connected to the reference potential unit 522 that is a discharging potential, and preferably, the drive voltage VCC is supplied to the first node ND52 of the resonance unit 511B. Need to be stopped.

  Based on this, as shown in the signal waveform in FIG. 12B, the supply of the drive voltage VCC to the first node ND52 of the resonance unit 511B is stopped so that the resonance energy is efficiently discharged. In addition, the second magnetic field generation stop signal STP2 is supplied from the control unit 40 to the drive power supply unit 521B of the drive control circuit 52B at an active low level (L). When the drive power supply unit 521B receives the second magnetic field generation stop signal STP2 at the active low level (L), the transistor TR2 as the second switching element SW51 is turned off (OFF state). Along with the transition of the transistor TR2 to the non-conductive state, the supply of the drive voltage VCC from the drive power supply unit 521 to the first node ND52 of the resonance unit 511B is stopped.

  In parallel with this, as shown by the signal waveform in FIG. 12B, the first magnetic field generation stop signal STP1 is inactive at the low level (inactive level) so that the resonance energy of the resonance unit 511B is released (discharged). L) is switched to an active high level (H) and supplied from the control unit 40 to the discharge drive unit 524 of the drive control circuit 52B. In the discharge driver 524, when the first magnetic field generation stop signal STP1 is received at an active high level, the transistor TR1 that is the first switching element DSW52 is driven to a conductive state. Thereby, in the resonance unit 511B, the first node ND52 is electrically connected to the reference potential unit 522, and the resonance energy is discharged (discharged) from the first node ND52 of the resonance unit 511B. The resonance energy in the resonance part 511B is released (discharged) quickly (quickly).

  When the disturbing magnetic field is generated again after the release of the resonance energy and the processing such as opening the shutter 38, the operation similar to the operation described in the magnetic field generating operation is basically performed. Is done. However, in order to perform efficient switching and power supply of the operating voltage, when the magnetic field generation is resumed, the first magnetic field generation stop signal STP1 is set to the low level as shown in FIGS. 12B and 12C. After the transistor TR1 as the first switching element DSW52 is switched to the non-conductive state, the second magnetic field generation stop signal STP2 is switched to the high level, and the transistor TR1 as the second switching element SW51 is in the conductive state. Can be switched to.

  As described above, the magnetic field generator 50B according to the second embodiment can increase and continue the output of the disturbing magnetic field, change the resonance frequency, and generate a magnetic field whose frequency changes. It is possible to reliably prevent magnetic data from being illegally acquired using a skimming magnetic head with high accuracy, to prevent erroneous detection of a magnetic field by the pre-head 39, and to control the opening and closing of the shutter 38. This can be done with good responsiveness, and even when the card is quickly inserted, the occurrence of an event such as a card hitting (collision) with the shutter 38 can be suppressed.

[Third embodiment of magnetic field generator]
Next, a magnetic field generator according to the third embodiment will be described.
FIG. 14 is a circuit diagram showing a magnetic field generator and a drive control circuit of a magnetic field generator according to the third embodiment of the present invention.

  The magnetic field generator 50C according to the third embodiment is different from the magnetic field generator 50B of FIG. 8 according to the second embodiment described above as follows. In the drive control circuit 52C of the magnetic field generator 50C, in FIG. 12, an npn-type transistor formed by a high-power bipolar transistor of the discharge drive unit is formed by an n-channel field effect transistor (an NMOS transistor TR1N which is an FET). Similarly, in the drive control circuit 52C, the transistor formed by the npn-type transistor of the drive power supply unit is formed by the NMOS transistor TR2n which is an n-channel FET in FIG.

  Other configurations are the same as those of the second embodiment, and according to the third embodiment, the same effects as those of the second embodiment described above can be obtained.

[Card reading / ejecting operation of card reader]
Finally, as an example, the card MC taking-in and discharging operations of the card reader 10 will be described in association with the drive timing of the magnetic field generator 50B.

  First, the capturing operation will be described with reference to FIG. 15, FIG. 16, and FIG. FIG. 15 is a flowchart for explaining the operation at the time of taking in the card. FIG. 16 is a flowchart for explaining an example of the operation of generating a disturbing magnetic field. FIG. 17 is a diagram for explaining the operation when the card is taken in.

Here, under the control of the control unit 40, the drive control circuit 52B of the magnetic field generator 50B is driven to generate a disturbing magnetic field for the skimming magnetic head (step ST1).
In the generation of the disturbing magnetic field, as shown in FIG. 16, the frequency switching control signal SFS is supplied from the control unit 40 to the on / off switch SW531 of the frequency changing unit 53A at an inactive low level, and the resonance circuit The resonance frequency is set (changed) to the first resonance frequency fr1 [= 1 / (2π√LvCv1)] (step ST101 in FIG. 16). When a preset predetermined time TM elapses in the state where the disturbing magnetic field is generated at the first resonance frequency fr1 (step ST102 in FIG. 16), the control unit 40 switches the on / off switch SW531 of the frequency changing unit 53A. Thus, the frequency switching control signal SFS is supplied at an active high level, and the resonance frequency of the resonance circuit is set (changed) to the second resonance frequency fr2 [= 1 / (2π√Lv (Cv1 + Cv2) (FIG. 16). Step ST103) When a predetermined time TM has elapsed in a state in which the disturbing magnetic field is generated at the second resonance frequency fr2 (Step ST104 in FIG. 16), the process proceeds to Step ST101, and the resonance frequency is set. Is changed from the second resonance frequency fr2 to the first resonance frequency fr1, thus generating a disturbing magnetic field. The should period, the process of step ST104 from step ST101 in FIG. 16 are repeated.

  When the user inserts the card MC into the card insertion slot 311 in the state where the disturbing magnetic field is generated (step ST2), the card inserted by the card detection sensor 371 is detected (step ST3). This detection information is supplied to the control unit 40.

  When the insertion of the card MC is detected, the control unit 40 next slides the magnetic stripe mp formed on the card MC by the pre-head 39, and reads the magnetic data written on the magnetic stripe mp. At this time, the control unit 40 reads the magnetic data of the card MC, and when the magnetic detection is performed, the control unit 40 generates a magnetic field in the same manner as described above so that the residual disturbing magnetic field does not affect the magnetic detection. Is stopped, and the first magnetic field generation stop signal STP1 and the second magnetic field generation stop signal STP2 are actively output (steps ST4 and ST5) in order to release (discharge) the resonance energy of the resonance unit 511B of the drive control circuit 52B. ). In this state, the magnetic stripe formed on the inserted card MC is detected by the pre-head 39 for detecting card insertion (step ST6). Based on the detection signal from the pre-head 39, the control unit 40 drives the drive control circuit 52B of the magnetic field generator 50B for a predetermined time to generate a disturbing magnetic field (step ST7). Generation of the disturbing magnetic field is performed in the same manner as in FIG. Then, with the disturbing magnetic field generated, the controller 40 opens the shutter 38 (step ST8), activates the drive motor 36 (step ST9), and drives the transport system including the take-in roller pair 331.

  As a result, the card MC can be taken inside. When the card MC is inserted beyond the position of the shutter 38, the leading end is inserted into the take-out and discharge roller 331, and the taking-in operation of the card MC is started (step ST10).

  Here, in this example, after the card MC starts to be taken in, for example, while the rear end of the card MC protrudes from the card insertion slot 311, the magnetic field generator 50 B generates a disturbing magnetic field, and thereafter The generation of the disturbing magnetic field is stopped (step ST11). The generation time of the disturbing magnetic field can be managed by the elapsed time from the detection time by the card insertion detection pre-head 39, the card detection sensor 37, or the like.

  Next, after the card MC is taken to the position of the magnetic head 31 for reading, the reading operation or writing operation of the card MC is performed by the magnetic head 34 (step ST12).

  Thus, in the taking-in operation of the card MC of this example, the disturbing magnetic field is generated when the rear end of the card MC protrudes from the card insertion slot 311. As a result, for example, as shown by an imaginary line in FIG. 17, even if the skimming magnetic head device 61 is attached to the external side position of the card insertion slot 311, for example, the surface of the front panel 20 of the host device. Due to the generation of the magnetic field, the magnetic data of the inserted card MC cannot be completely read by the skimming magnetic head 61. Therefore, unauthorized reading of magnetic data by the skimming magnetic head 61 can be prevented.

  Next, the discharging operation will be described with reference to FIGS. FIG. 18 is a flowchart for explaining the operation at the time of card ejection. FIG. 19 is a diagram for explaining the operation when the card is ejected.

  In this case, the discharge operation of the card MC is started by the rollers 331, 332, 333 (step ST21), and when the leading end of the discharged card MC in the discharge direction is detected by the card detection sensor 371 (step ST22), a magnetic field is generated. Device 50B is driven and a disturbing magnetic field is generated (step ST23). Generation of the disturbing magnetic field is performed in the same manner as in FIG.

  Thereafter, when the rear end of the card MC ejected by the photosensor 352 is detected (step ST24), the drive motor 36 is stopped (step ST25), and the card ejection operation is terminated. Thereafter, the control unit 40 stops driving the drive control circuit 52B of the magnetic field generator 50 and stops the generation of the disturbing magnetic field (step ST26).

  At the time when the card ejection operation is completed, the rear end of the card MC is in the state of being inserted into the transport roller 331. When the user pulls the card MC lightly, the card MC can be taken out from the card insertion slot 311. If the user forgets to take out the card MC, the card roller MC 36 can be recovered by driving the pair of transport rollers 36 after a predetermined time has elapsed.

  As described above, in the card reader 10 of this example, even when the card is ejected, the disturbing magnetic field is temporarily generated in a state where the leading end portion on the ejection side protrudes from the card insertion slot 311. . Therefore, even if the skimming magnetic head 61 device is attached to the front panel surface, it is possible to prevent the magnetic data of the card MC ejected by the skimming magnetic head 61 device from being read.

  In this example, the driving of the magnetic field generator 50B is driven only once for a predetermined period at the time of card insertion and ejection, but may be intermittently driven twice or more. Well, various embodiments are possible.

[Main effects of the embodiment]
As described above, the following effects can be obtained in the present embodiment.
In the present embodiment, basically, an LC parallel resonance circuit formed by connecting a coil L, which is an inductor, and a capacitor C is provided, and a strong magnetic field is generated by the LC parallel resonance circuit for a predetermined period of time due to resonance energy retention characteristics. Occurs continuously. In this embodiment, the resonance unit 511 has a function of changing the resonance frequency, for example, periodically (or randomly) by the switching operation by the frequency changing unit 53, and a plurality of (two in the example of FIG. 5). ) Can be generated. As a result, it is possible not only to increase the output of the disturbing magnetic field, but also to change the resonance frequency, to generate a magnetic field whose frequency changes, and to illegally store magnetic data using the skimming magnetic head. Can be reliably prevented with high accuracy. Further, by generating a disturbing magnetic field whose frequency changes at an appropriate timing, it is possible to make it extremely difficult to read the data of the card MC by the skimming device. Further, by using a plurality of capacitors, a magnetic field whose frequency changes can be generated even if there are not a plurality of magnetic field radiation sources (coils, etc.) or a drive source for the magnetic field radiation source, thereby preventing an increase in size of the apparatus. be able to.

  Therefore, according to this embodiment, in order for an unauthorized person to read the magnetic data of the card, so-called skimming including a skimming magnetic head and a magnetic reading circuit at the card insertion slot of the card reader on the outside of the front panel. Even if the magnetic head device (skimmer) 60 is attached, it is possible to generate a strong magnetic field, increase the output of the disturbing magnetic field, change the resonance frequency, and change the frequency. A magnetic field can be generated, and illegal acquisition of magnetic data using a skimming magnetic head can be reliably prevented with high accuracy.

  Furthermore, according to the present embodiment, the resonance unit 511 has a function of changing the resonance frequency, for example, periodically (or randomly) by the switching operation by the frequency changing unit 53, and a plurality of (in the example of FIG. 5). It is configured to be able to generate a disturbing magnetic field having two frequencies. As a result, it is possible not only to increase the output of the disturbing magnetic field, but also to change the resonance frequency, to generate a magnetic field whose frequency changes, and to illegally store magnetic data using the skimming magnetic head. Can be reliably prevented with high accuracy. Further, by generating a disturbing magnetic field whose frequency changes at an appropriate timing, it is possible to make it extremely difficult to read the data of the card MC by the skimming device. Further, according to the configuration using a plurality of capacitors, a magnetic field whose frequency changes can be generated even if there are not a plurality of magnetic field radiation sources (coils, etc.) or driving sources of the magnetic field radiation source, and thus the size of the apparatus can be increased. Can be prevented.

Further, according to the present embodiment, in the magnetic field generator 50B, the transistor TR1 as the first switching element DSW52 for discharge is connected to the first node ND52 of the resonance unit 511B, and the resonance energy emission path (discharge path). , Have a way to escape.
Further, in the magnetic field generation device 50B, supply of the power supply voltage VCC to the first node ND52 of the resonance unit 511B is stopped when generation of the disturbing magnetic field is stopped in the supply line to the resonance unit 511B of the power supply voltage VCC of the drive power supply unit 521B. The transistor TR2 as the second switching element SW51 is connected. As a result, according to the present embodiment, the output of the disturbing magnetic field can be increased and continued, the resonance frequency can be changed, a magnetic field with a changing frequency can be generated, and the skimming magnetic head It is possible to reliably prevent magnetic data from being illegally acquired with high accuracy, to prevent erroneous detection of a magnetic field by the pre-head 33-2, and to perform shutter opening / closing control with good responsiveness. Thus, even when the card is quickly inserted, it is possible to suppress the occurrence of an event such as the card hitting the shutter (collision).

  When the magnetic field generator 50B stops the resonance of the resonance unit 511B and releases the resonance energy, the transistor TR2 as the second switching element SW51 of the drive power supply unit 521B is turned off (OFF state) to drive voltage VCC. Is stopped, and then the transistor TR1 as the first switching element DSW52 for discharge is made conductive (ON state) to release the resonance energy. As a result, resonance energy can be efficiently discharged (discharged).

  In addition, the magnetic field generator 50B of the second embodiment switches the transistor TR1 as the first switching element DSW52 for discharging to a non-conductive state at the start (resumption) of magnetic field generation, and then the second switching element. The transistor TR2 as the SW55 is configured to be switched to a conductive state. As a result, magnetic field generation can be started or restarted efficiently.

  Further, according to the magnetic field generator according to the present embodiment, in order for an unauthorized person to read the magnetic data of the card, the skimming magnetic head and the magnetic reading are provided on the card insertion slot of the card reader on the outside of the front panel. Even if a so-called skimmer including a circuit is attached, a magnetic field can be generated, the output of the disturbing magnetic field can be increased and continued, and the resonance frequency can be changed to generate a magnetic field whose frequency changes. It is possible to reliably prevent illegal acquisition of magnetic data with high accuracy. Further, in this embodiment, the magnetic field generated by the disturbing magnetic field is set at the time of card insertion and ejection, so that the operation by the internal recording / reproducing magnetic head is obstructed without providing a magnetic shielding plate or the like. There is no.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described concretely, it cannot be overemphasized that this invention can be variously deformed in the range which is not limited to the said embodiment and does not deviate from the summary.

  For example, in the above-described embodiment, as shown in FIG. 3, the parallel resonance circuit of the magnetic field generator 51 is formed by winding L1 around the iron core fc and winding the coil L1. However, as shown in FIG. It is also possible to form by L1.

  DESCRIPTION OF SYMBOLS 10 ... Card reader (magnetic recording medium management device), 20 ... Front panel, 21 ... Opening, 30 ... Card processing part, 31 ... Magnetic head, 311 ... Card insertion slot, 37 ... Card insertion detection mechanism, 371 ... Card detection sensor, 38 ... Shutter, 39 ... Pre-head, 40 ... Control part, 50, 50A-50C ... Magnetic field generator, 51. ..Magnetic field generator, 511, 511A, 511B ... resonance unit, 52, 52A, 52B ... drive control circuit, 521,521B ... drive power supply unit, 522 ... reference potential unit, 523 ... Resonance drive unit, 524, 524B ... discharge drive unit, 53, 53A to 53E ... frequency change unit, 531, 531A-531D ... switching unit, 5311 ... relay switch, 5312 ... support Lister (triac), 5313 ... Thyristor (triac) control circuit, 5314 ... SSR (semiconductor relay), 5315 ... SSR (semiconductor relay) control circuit, ND51 ... Connection node, ND52 ... No. 1 node, ND53 ... 3rd node, L51 ... inductor, C51, C52, C53 ... capacitor, DSW51 ... drive switching element, DSW52 ... 1st switching element, SW51 ... -2nd switching element, MC ... card.

Claims (13)

A drive power supply for supplying drive voltage;
A reference potential section;
A resonance circuit including an inductor and a capacitor connected between the first node and the second node; the driving voltage received by the first node; and the second node connected to a reference potential unit A resonating unit that resonates at a frequency set in a state and generates a magnetic field;
A frequency changing unit capable of changing a resonance frequency of the resonance unit;
A magnetic field generator comprising: The frequency changing unit is
The magnetic field generator according to claim 1, wherein the resonance frequency of the resonance unit is changed to a plurality of different resonance frequencies during a period in which a magnetic field is generated by the resonance unit. The resonant circuit is:
The inductor and one or more capacitors are connected in parallel,
The frequency changing unit is
The magnetic field generator according to claim 1, further comprising a switching unit that switches connection between one or a plurality of the capacitors and the inductor. The second node of the resonance unit is connected between the second node and the reference potential unit, and is switched between a conduction state and a non-conduction state according to a control signal. The second node of the resonance unit and the reference potential unit The magnetic field generator according to claim 1, further comprising: a resonance drive unit including a drive switching element that switches between a connected state and a non-connected state. The first node of the resonance unit is connected between the first node of the resonance unit and the discharging potential unit, and is switched between a conduction state and a non-conduction state according to a first magnetic field generation stop signal. And a discharge driving unit including a first switching element that switches between a connected state and a non-connected state between the discharge potential unit and the discharge potential unit,
The drive power supply unit
Connected between the drive voltage supply source and the first node of the resonance unit, and switched between a conduction state and a non-conduction state in response to a second magnetic field generation stop signal; The magnetic field generator according to claim 4, further comprising: a second switching element that switches a connection state and a non-connection state of the resonance unit with the first node. A magnetic generation device including a magnetic field generation unit that generates a magnetic field by a resonance unit and a drive control circuit that drives and controls the magnetic field generation unit;
The drive control circuit of the magnetic generator is
A drive power supply for supplying drive voltage;
A reference potential section;
A frequency changing unit capable of changing a resonance frequency of the resonance unit,
The resonance part is
A resonance circuit including an inductor and a capacitor connected between the first node and the second node; the driving voltage received by the first node; and the second node connected to a reference potential unit A magnetic recording medium processing apparatus characterized by resonating at a frequency set by the frequency changing unit and generating a magnetic field. The frequency changing unit is
The magnetic recording medium processing apparatus according to claim 6, wherein the resonance frequency of the resonance unit is changed to a plurality of different resonance frequencies during a period in which a magnetic field is generated by the resonance unit. The resonant circuit is:
The inductor and one or more capacitors are connected in parallel,
The frequency changing unit is
The magnetic recording medium processing apparatus according to claim 6, further comprising a switching unit that switches connection between the one or more capacitors and the inductor. The second node of the resonance unit is connected between the second node and the reference potential unit, and is switched between a conduction state and a non-conduction state according to a control signal. The second node of the resonance unit and the reference potential unit The magnetic recording medium processing device according to claim 6, further comprising: a resonance driving unit including a drive switching element that switches between a connected state and a non-connected state. The first node of the resonance unit is connected between the first node of the resonance unit and the discharging potential unit, and is switched between a conduction state and a non-conduction state according to a first magnetic field generation stop signal. And a discharge driving unit including a first switching element that switches between a connected state and a non-connected state between the discharge potential unit and the discharge potential unit,
The drive power supply unit
Connected between the drive voltage supply source and the first node of the resonance unit, and switched between a conduction state and a non-conduction state in response to a second magnetic field generation stop signal; The magnetic recording medium processing device according to claim 9, further comprising: a second switching element that switches a connection state and a non-connection state of the resonance unit with the first node. A detection mechanism for detecting a card-like magnetic recording medium inserted or ejected from the insertion slot;
A pre-head that reads magnetic data by sliding on a magnetic stripe formed on the card-like magnetic recording medium;
A shutter that is opened and closed according to a detection result of the detection mechanism,
A card processing unit for processing magnetic information recorded on a card-like magnetic recording medium;
A control unit that drives and controls the magnetic field generator according to the detection result of the detection mechanism unit and the detection information of the pre-head,
The controller is
When the recording medium is detected by the detection mechanism, the magnetic field generation of the magnetic field generator is stopped,
The magnetic recording medium processing apparatus according to claim 8, wherein magnetic field generation of the magnetic field generator is started after magnetic information is detected by the pre-head. A magnetic generation device including a magnetic field generation unit that generates a magnetic field by a resonance unit and a drive control circuit that drives and controls the magnetic field generation unit;
The drive control circuit of the magnetic generator is
A drive power supply for supplying drive voltage;
A reference potential section;
A frequency changing unit capable of changing a resonance frequency of the resonance unit,
The resonance part is
A resonance circuit including an inductor and a capacitor connected between the first node and the second node; the driving voltage received by the first node; and the second node connected to a reference potential unit When controlling magnetic field generation in a magnetic recording medium processing apparatus that resonates at a frequency set by the frequency changing unit in a state and generates a magnetic field,
A method for controlling a magnetic recording medium processing apparatus, wherein the resonance frequency of the resonance unit is changed to a plurality of different resonance frequencies during a period in which a magnetic field is generated by the resonance unit. The method of controlling a magnetic recording medium processing device according to claim 12, wherein the resonance frequency is changed by switching connection between the one or more capacitors and the inductor.

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