JP6680931B2 - Magnetic field generator, magnetic field generator control method, and magnetic recording medium processing apparatus - Google Patents

Description

  The present invention relates to a magnetic field generator that generates a disturbing magnetic field, a method of controlling the magnetic field generator, and a magnetic field generator that reads magnetic data recorded on a magnetic recording medium and / or writes magnetic data to the magnetic recording medium. The present invention relates to a magnetic recording medium processing device provided.

Conventionally, a card as a magnetic recording medium processing device for reading magnetic data recorded in a card-shaped magnetic recording medium (hereinafter referred to as “card”) as a magnetic recording medium and / or writing magnetic data to the card. Readers are widely used. This type of card reader is used by being mounted in a higher-level device such as an ATM (Automatic Teller Machine) installed in a financial institution such as a bank.
Further, 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 opening of the card reader and illegally acquires magnetic data of the card with this magnetic head. Skimming is a big problem.

  Therefore, conventionally, a magnetic field generator for generating an interfering magnetic field for obstructing reading of magnetic data of a card by a magnetic head for skimming (hereinafter, referred to as a "magnetic head for skimming") mounted in front of a card insertion slot. A card reader provided with is proposed (for example, refer to Patent Document 1). In the card reader described in Patent Document 1, a magnetic field (magnetism) generator is provided at a card insertion port of the card reader, and a magnetic head for skimming uses a card by a disturbing magnetic field (magnetism) emitted from the magnetic field (magnetism) generator. A technique for preventing reading of magnetic data of a person is disclosed.

  In this technology, a circuit that generates a disturbing magnetic field employs a configuration in which a coil (inductor) power source is driven by a transistor having a switch function.

  In the card reader shown in Patent Document 1, the above-mentioned magnetic field (magnetism) generator is applied as follows. A fraudulent person attaches a skimming magnetic head, which is a magnetic head, and a magnetic reading circuit to the card insertion opening of the card reader in order to read the magnetic data of the card. In order to prevent the magnetic data from being read from the skimming magnetic head, a disturbing magnetic field is generated toward the skimming magnetic head.

Japanese Unexamined Patent Publication No. 2001-67524 (or Japanese Patent No. 3936496)

  However, since the magnetic field generator used in Patent Document 1 is a circuit that drives the power supply of the coil (inductor) with a transistor having a switch function, the magnetic field is sporadically generated and the disturbance time is Sometimes it was short or the magnetic field was weak.

  Then, the subject of this invention is providing the magnetic field generator which can generate | occur | produce a disturbance magnetic field continuously and efficiently, the control method of a magnetic field generator, and a magnetic recording medium processing apparatus.

  A magnetic field generator according to a first aspect of the present invention includes a resonance unit to which an inductor and a capacitor are connected, and charges the capacitor and discharges the charged charge to thereby generate an alternating current between the inductor and the capacitor. Magnetic field generating unit for generating a magnetic field by causing the current to flow, a current direction monitoring unit monitoring the direction of the current flowing in the inductor of the magnetic field generating unit, and a current flowing in the inductor obtained by the monitoring of the current direction monitoring unit. And a determination unit that controls the charging timing of the magnetic field generation unit according to the current direction.

  As a result, it is possible to continue the generation of the disturbing magnetic field, and by monitoring the direction of the current flowing through the inductor, it is possible to optimize the timing at which a direct current is passed through the capacitor of the resonance section to store electric charge. It is possible to control the disturbing magnetic field with high accuracy and efficiency.

Preferably, a first direction current flowing from one end side to the other end side and a second direction current flowing from the other end side to the one end side alternately flow in the inductor, and the determination unit monitors the current direction. A current direction determination unit that determines whether or not the current flowing through the inductor has changed to the first direction current based on the monitoring result of the unit, and the magnetic field generation unit because the current flowing through the inductor has changed to the first direction current. And an operation instructing unit that controls driving so as to charge the battery.
With this, it is determined whether the current flowing through the inductor has changed to the first direction current based on the monitoring result of the current direction monitoring unit. Therefore, it is possible to accurately adjust the timing of storing a charge by flowing a DC current through the capacitor of the resonance unit with high accuracy. Can be realized in.

Preferably, the determination unit has a time determination unit that determines whether or not a preset resonance time has elapsed after stopping the charging, the operation instruction unit, the resonance time has elapsed, After confirming that the current flowing in the inductor has changed to the first direction current, drive control is performed so as to charge the magnetic field generation unit.
This makes it possible to judge the preset resonance time and confirm that the current has shifted in the first direction after a suitable time has elapsed. It is possible to realize the optimization of the timing for storing the with high accuracy.

Preferably, the time determination unit of the determination unit determines whether or not a preset monitoring time has elapsed after the resonance time has elapsed, and the operation instruction unit has the monitoring time elapsed and the inductor When the current flowing in the first direction current does not change to the first direction current, drive control is performed so as to charge the magnetic field generation unit.
With this, the time determination unit determines whether or not the preset monitoring time has elapsed, and the operation instructing unit determines that the magnetic field when the current flowing through the inductor does not turn into the first direction current after the monitoring time has elapsed. Since the drive control is performed so as to charge the generation unit, charging and resonance can be continuously performed for a desired period.

Suitably, the time determination unit of the determination unit determines whether or not a preset charging time has elapsed, and the operation instructing unit determines whether or not the current direction monitoring unit monitors within the charging time. When the current flowing through the inductor changes to the first direction current, the resonance is started after the charging time ends.
As a result, when the operation instructing unit recognizes that the preset charging time Tc has elapsed, the operation instructing unit drives and controls the magnetic field generating unit to the resonance state, so that the resonance can be started at an appropriate timing.

Preferably, the operation instruction unit of the determination unit terminates the drive control of the magnetic field generation unit as an abnormality when the current flowing through the inductor does not turn into the first direction current within the charge time.
As a result, when the current flowing in the inductor does not turn into the first direction current, the determination unit terminates the drive control of the magnetic field generation unit as an abnormality, so that the malfunction of the resonance unit due to damage or the like can be detected. As a result, the reliability of the magnetic field generator can be improved.

Preferably, the determination unit determines whether or not a preset resonance time has elapsed after stopping the charging, and determines whether or not a preset monitoring time has elapsed after the resonance time has elapsed. A current direction determination unit that acquires the number of times of reversal of the current flowing through the inductor in the resonance time based on the monitoring result of the current direction monitoring unit; When the acquired number of inversions is equal to or greater than the specified number, the drive control of the magnetic field generation unit is performed according to the current flowing through the inductor according to the monitoring result of the current direction monitoring unit within the monitoring time.
Thereby, the current direction determination unit acquires the number of times of reversal of the current flowing through the inductor within the resonance time, and the operation instruction unit determines the number of times of reversal according to the current flowing through the inductor when the acquired number of times of reversal is the specified number or more. Since the drive control of the magnetic field generation unit is performed, it is possible to realize the optimization of the timing at which the direct current is passed through the capacitor of the resonance unit to store the charge with higher accuracy.

Preferably, the operation instruction unit of the determination unit terminates the drive control of the magnetic field generation unit as an abnormality when the acquired number of inversions does not reach a specified number within the resonance time.
Alternatively, the time determination unit of the determination unit determines whether or not a preset monitoring time has elapsed, and the operation instructing unit determines that the current flowing through the inductor after the monitoring time has passed the first direction. When the current does not change to the current, the drive control of the magnetic field generation unit is terminated as an abnormality without performing the drive control so as to charge the magnetic field generation unit.
This allows the determination unit to constantly monitor the current state of the coil, which is the inductor, to detect malfunctions due to damage to the resonance unit, etc., and improve the reliability of the magnetic field generator. Becomes

  A method of controlling a magnetic recording medium processing apparatus according to a second aspect of the present invention includes a resonance part to which an inductor and a capacitor are connected, and charges the capacitor with electric charge and discharges the charged electric charge to form the inductor. When controlling the drive of the magnetic field generation unit that generates a magnetic field by resonance by passing an alternating current between the capacitors, the direction of the current flowing through the inductor of the magnetic field generation unit is monitored, and the direction of the current flowing through the inductor is obtained. The charging timing of the magnetic field generator is controlled according to the current direction.

  As a result, it is possible to continue the generation of the disturbing magnetic field, and by monitoring the direction of the current flowing through the inductor, it is possible to optimize the timing at which a direct current is passed through the capacitor of the resonance section to store electric charge. In addition, it is possible to control the disturbing magnetic field with high accuracy and efficiency.

A third aspect of the present invention is a magnetic recording medium processing device for processing magnetic information recorded on a magnetic recording medium, the magnetic field generating device generating a magnetic field for obstructing reading of magnetic information from a magnetic recording medium. The magnetic field generation device includes a resonance part to which an inductor and a capacitor are connected, and charges an electric current to the capacitor and discharges the charged electric charge to generate an alternating current between the inductor and the capacitor. A magnetic field generator that generates a magnetic field by sinking resonance, a current direction monitor that monitors the direction of current flowing in the inductor of the magnetic field generator, and a current direction that flows in the inductor obtained by monitoring the current direction monitor And a determination unit that controls the charging timing of the magnetic field generation unit.
As a result, it is possible to optimize the timing at which a direct current is passed through the capacitor of the resonance section to store the charges, and it is possible to perform the interference magnetic field control with high accuracy and efficiency.
Then, in the magnetic recording medium processing device, it is possible to continuously and efficiently generate an interfering magnetic field with an appropriate time and intensity, and it is possible to reliably prevent illegal acquisition of magnetic data with high accuracy. Becomes

  According to the present invention, it is possible to continuously and efficiently generate a disturbing magnetic field.

It is a figure which shows schematic structure of the principal part of the card reader as a magnetic recording medium processing apparatus which concerns on 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. FIG. 2 is a block diagram showing a schematic configuration of a control unit of the card reader shown in FIG. 1 and its related parts. It is a block diagram showing the 1st example of composition of the drive control circuit concerning this embodiment. 6 is a block diagram showing a second configuration example of the drive control circuit according to the present embodiment. FIG. FIG. 3 is a diagram schematically showing a state in which a skimming magnetic head device is attached to the outside of the device. FIG. 3 is a circuit diagram showing a magnetic field generator, a drive control circuit, and a current direction monitoring circuit of the magnetic field generator according to the embodiment of the present invention. It is a waveform diagram for explaining the operation of the magnetic field generator according to the present embodiment. 5 is a flowchart for explaining an operation when the first configuration example of FIG. 4 is adopted as a drive control circuit. 6 is a flowchart for explaining an operation when the second configuration example of FIG. 5 is adopted as a drive control circuit. FIG. 9 is a waveform diagram showing a state in which charging and resonance operations are normally performed when current direction monitoring is not performed. FIG. 6 is a waveform diagram showing a state in which charging and resonance operations are not performed normally when the current direction is not monitored. It is a flow chart for explaining operation at the time of card loading. It is a figure for explaining operation at the time of taking in a card. 6 is a flowchart for explaining an operation when ejecting a card. It is a figure for explaining operation at the time of card ejection. 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, as a magnetic recording medium processing device, a card reader that reads magnetic data recorded on a card-shaped recording medium or records magnetic data will be described as an example.

  In the following, first, a schematic configuration of the card reader according to the present embodiment will be described, and then a specific circuit configuration and operation of a magnetic field generation device that generates an interference magnetic field will be described. Then, the operation of taking in and ejecting the card of the card reader will be described in association with 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 device 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 device according to this embodiment.

The card reader 10 of the present embodiment is a magnetic recording medium processing device for reading magnetic data recorded on the magnetic stripe mp formed on the card MC and / or writing magnetic data on the card MC. For example, it is used by being mounted in a predetermined higher-level device such as an automatic transaction machine (ATM) which is installed in a financial institution.
The card reader 10 is arranged on the back side of the front panel 20 that constitutes the front surface of the housing of the host device. The front panel 20 has 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 that controls the card reader 10, and a magnetic field generator 50 that generates an interfering magnetic field for preventing the reading of magnetic data of the card MC by the skimming magnetic head. It has and.
Inside the card reader 10, a card transport path 32 for transporting the card MC inserted from the card insertion slot 311 is formed. A control unit 40 that performs various controls of the card reader 10 is mounted on a circuit board (not shown).

  In this embodiment, the card MC is conveyed in the X direction (left and right direction) of FIGS. 1 and 2. That is, the X direction is the card MC carrying direction. Further, the Z direction (vertical direction) of FIG. 1 is the thickness direction of the card MC, and the Y direction of FIG. 1 and FIG. 2 (the direction perpendicular to the paper surface of FIG. 1) orthogonal to the X and Z directions is the card. It is the width direction (widthwise direction) of the 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 this card MC. An IC chip may be fixed to the card MC, or a communication antenna may be built in. The card MC may be a PET (polyethylene terephthalate) card having a thickness of about 0.18 to 0.36 mm, or a paper card having a predetermined thickness.

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

  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). The card transport mechanism 33 also includes pad rollers 334 to 336 that are arranged to face the transport rollers 331 to 333 and are biased toward the transport rollers 331 to 333, respectively. The three transport rollers 331 to 333 are arranged in the card MC transport direction with a predetermined gap therebetween.

  The transport rollers 331, 332, 333 are rotationally driven by the drive motor 36 under the control of the control unit 40.

  As shown in FIG. 1, in the magnetic head 34, the center of rotation of the carry roller 332 arranged in the center of the card processing unit 30 and the center of the magnetic head 34 are substantially aligned in the X direction in the card MC carrying direction. Are arranged as follows. Further, on the magnetic head 34, a facing pad roller 335 is provided to face the card MC passing through the card transport path 32 so as to apply a biasing force toward the magnetic head 34.

  The photo sensor 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 front end of the card MC is detected by the photo sensor 351, and immediately before the card MC is not detected by the photo sensor 351. Finish reading. That is, in this embodiment, the photo sensor 351 can detect whether or not the magnetic head 34 is reading magnetic data.

  The card insertion portion 31 includes a card insertion detection mechanism 37 for detecting whether or not the card MC is inserted through the card insertion opening 311, a shutter 38 for opening and closing the card transport path 32, and a magnetic field recorded on the magnetic stripe mp. A pre-head (magnetic head) 39 for reading data is provided.

  For example, as shown in FIG. 2, the card insertion detection mechanism 37 is turned on when one end of the inserted card MC in the width direction is pressed in the lateral direction (Y direction), and is released to release the pressed state. It has a card width sensor 371 as a card detection sensor that turns off.

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

  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 that directly contacts the end portion of the card MC in the width direction.

  The pre-head 39 is arranged near the card insertion slot 311 in the card MC transport direction. Specifically, the pre-head 39 is arranged in the vicinity of the card insertion detection mechanism 37, for example, in the vicinity of the contact portion of the card width sensor 371 with the card MC. In the present embodiment, the pre-head 39 reads the magnetic data recorded in the magnetic stripe mp immediately after the card insertion detection mechanism 37 detects the tip of the card MC and before the card insertion detection mechanism 37 stops detecting the card MC. The magnetic data reading is completed. That is, in this embodiment, it is possible to detect whether or not the 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 part (resonance circuit) to which an inductor and a capacitor are connected, and charges the capacitor with electric charge and discharges the charged electric charge to flow an alternating current between the inductor and the capacitor. It has a magnetic field generation unit that generates a magnetic field by resonance, a current direction monitoring circuit that monitors the direction of the current flowing through the inductor of the magnetic field generation unit, and a drive control unit that drives and controls the magnetic field generation unit.
The specific configuration of the magnetic field generator 50 will be described later in detail.

[Schematic configuration of control unit of card reader]
FIG. 3 is a block diagram showing a schematic configuration of the control unit 40 of the card reader 10 shown in FIG. 1 and its related parts. 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 controller 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 carrying operation of the card MC, the reading operation by the magnetic head 34, and the like according to the control program stored in the built-in ROM. Further, a photo sensor 35, a card width sensor 371 as a card detection sensor, and a pre-head 39 are connected to the control unit 40, and output signals from these components are input. Further, the drive motor 36 is connected to the control unit 40 via a driver 42. Further, an encoder 361 is connected to the control unit 40, and an output signal from the encoder 361 that detects the rotation state of the drive motor 36 and the like is input.

  Further, in the present embodiment, the control unit 40 is connected to the illegally attached magnetic head for skimming to which the magnetic field generator 50 that generates an interfering magnetic field is connected. The magnetic field generation device 50 performs drive control such as magnetic field generation or stop of magnetic field generation according to the card detection result of the 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 generation device 50 of the present embodiment includes a magnetic field generation unit 51, a drive control circuit (drive control unit) 52 for driving and controlling the magnetic field generation by the magnetic field generation unit 51 and the stop of the magnetic field generation unit 51, and the magnetic field generation unit 51. It has a current direction monitoring circuit 53 for monitoring the direction of the current flowing through the inductor.

The magnetic field generator 51 includes a coil L51 as an inductor for generating a magnetic field. The coil L51 is formed by winding a coil CL around an iron core FC, as shown in FIG. 3, for example. In the present embodiment, the magnetic field generation unit 51 is arranged in the card insertion unit 31.
In the magnetic field generation unit 51, the coil L51 is connected in parallel with the capacitor C51 to form a resonance unit (parallel resonance circuit), and a disturbance magnetic field is continuously generated, as will be described later in detail. The magnetic field generator 51 is drive-controlled so as to continuously generate an interfering magnetic field for a proper time and intensity.

As described above, the magnetic field generation device 50 can be configured by the parallel resonance circuit in which the coil (inductor) L51 and the capacitor (capacitor) C51 are connected in parallel.
In this parallel resonance circuit, first, a direct current is passed through the capacitor C51 to store electricity (charge, resonance energy) (hereinafter, referred to as "charge"), and then electricity (charge) stored in the capacitor C51. AC current is caused to flow between the coil (inductor) L51 and the capacitor C51 by discharging (hereinafter, this is referred to as "resonance").
As a result, the magnetic field generator 50 applies mutual induction to the coil of the skimming magnetic head to disturb the output, and interferes with the exploitation of magnetic data by a fraudulent person.

However, in the magnetic field generator, when the charging and the resonance are repeatedly performed continuously, the counter electromotive force is generated if the charging is performed at the timing when the current of the coil L51 flows in the opposite direction during the resonance (the capacitor is discharging). As a result, the power supply circuit (driving power supply unit) may be damaged, and the effect of this counter electromotive force may reduce the charging efficiency of the capacitor C51, which may reduce the interference output intensity to the skimming magnetic head. is there.
Therefore, in the present embodiment, as will be described in detail below, in the magnetic field generation device 50, the direct current is passed through the capacitor C51 of the parallel resonance circuit by performing the direction monitoring of the alternating current flowing through the coil L51. In order to optimize the timing of storing the electric charge, the timing of charging the magnetic field generation unit 51 is controlled according to the direction of the current flowing through the coil L51 obtained by the monitoring of the current direction monitoring circuit 53.

When the magnetic field generation device 50 resonates, the coil L51, which is an inductor, has a first direction current (forward direction current) directed from one end side to the other end side of the coil L51 and a second direction current directed from the other end side to the one end side. Directional current (reverse direction current) flows alternately.
In the present embodiment, as shown in FIG. 3, the current flowing from the one end TP1 side to the other end TP2 side of the coil L51 is referred to as the first direction current (forward current) IL1 and the other end TP2 side is used. A current flowing toward the one end TP1 side is defined as a second direction current (reverse direction current) IL2.

The current direction monitoring circuit 53 detects the potentials at both ends TP1 and TP2 of the coil L51, compares the potentials of the potentials, and outputs a comparison output signal DIR indicating the comparison result to the drive control circuit 52.
In the present embodiment, the current direction monitoring circuit 53 drives the comparison output signal DIR at a low level (L), for example, when the potential on the one end TP1 side of the coil L51 is higher than the potential on the other end TP2 side. Output to.
On the other hand, the current direction monitoring circuit 53 controls the comparison output signal DIR at a high level (H), for example, when the potential on the one end TP1 side of the coil L51 is lower than (or below) the potential on the other end TP2 side. Output to the circuit 52.

The drive control circuit 52 controls the charging timing of the magnetic field generation unit 51 according to the direction of the current flowing through the coil L51 obtained by the monitoring of the current direction monitoring circuit 53.
The drive control circuit 52 switches the current flowing in the coil L51 from the second direction current IL2 to the first direction current IL1, so that the current flowing in the coil L51 switches from the second direction current IL2 to the first direction current IL1. The drive is controlled so that the magnetic field generator 51 is charged at a timing.
As a result, the magnetic field generation device 50 realizes, with high accuracy, the timing of accumulating charges by flowing a direct current through the capacitor of the resonance circuit.

When charging the magnetic field generation unit 51, the drive control circuit 52 outputs the charge signal CHG to the magnetic field generation unit 51 at an active level, for example, a high level, for a predetermined charging time Tc set in advance.
When the charging time (period) Tc has elapsed, the drive control circuit 52 switches the charge signal CHG to a low level of an inactive level and outputs it to the magnetic field generation unit 51 in order to drive and control the magnetic field generation unit 51 to a resonance state. To do.

The drive control circuit 52 stops the charging (after the charging time (period) elapses), and when a preset resonance time Tr elapses, the current flowing in the coil L51 is detected by the monitoring result of the current direction monitoring circuit 53. After confirming that the second direction current IL2 has changed to the first direction current IL1, the drive control is performed so that the magnetic field generator 51 is charged.
That is, when charging the magnetic field generation unit 51, the drive control circuit 52 outputs the charge signal CHG to the magnetic field generation unit 51 at an active level, for example, a high level, for a predetermined charging time Tc set in advance.

The drive control circuit 52 drives to charge the magnetic field generation unit 51 when the resonance time Tr has passed and the current flowing through the coil L51 does not turn into the first direction current IL1 even after the preset monitoring time Tm has passed. It is also possible to adopt a configuration for controlling.
As a result, the magnetic field generation device 50 can continuously perform charging and resonance for a desired period.

[First Configuration Example of Drive Control Circuit]
FIG. 4 is a block diagram showing a first configuration example of the drive control circuit according to the present embodiment.
The drive control circuit 52A of FIG. 4 includes a storage unit 521, a clock unit 522, a determination unit 523, and a driver 524 as a drive unit.

The storage unit 521 is composed of, for example, a non-volatile memory, and stores various data such as a preset charging time (period) Tc, resonance time (period) Tr, and monitoring time (period) Tm.
The determination unit 523 refers to various data of the charging time (period) Tc, the resonance time (period) Tr, and the monitoring time (period) Tm stored in the storage unit 521.
The clock unit 522 supplies the current time information CTM to the determination unit 523.

  The determination unit 523 is configured to include a time (period) determination unit 5231, a current direction determination unit 5232, and an operation instruction unit 5233.

The operation instruction unit 5233 of the determination unit 523 basically instructs and controls the operations of the time determination unit 5231, the current direction determination unit 5232, and the driver 524.
The operation instructing unit 5223 outputs the charge signal CHG output from the driver 524 according to the elapsed time of the charging time (period) Tc, the resonance time (period) Tr, and the monitoring time (period) Tm, and the direction of the current flowing through the coil L51. Control output timing.

The time determination unit 5231 responds to the operation instruction information from the operation instruction unit 5233, and based on the current time CTM supplied by the clock unit 522, the charge time (period) Tc and the resonance time (period) stored in the storage unit 521. It is determined whether Tr and the monitoring time (period) Tm have elapsed, and the result is supplied to the operation instruction unit 5233.
Further, the time determination unit 5231 supplies information indicating that the resonance time Tr has elapsed to the current direction determination unit 5232. Note that the information indicating that the resonance time Tr has elapsed can be configured to be supplied to the current direction determination unit 5232 via the operation instructing unit 5233.

  Upon receiving the information indicating that the resonance time Tr has elapsed, the current direction determination unit 5232 determines whether or not the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1, and the result is determined. It is supplied to the operation instruction unit 5233.

When the disturbing magnetic field is generated, the operation instructing unit 5233 first instructs the driver 524 to output the charge signal CHG at an active high level in order to start charging.
The operation instruction unit 5233 notifies the time determination unit 5231 and the current direction determination unit 5232 that the charge start instruction has been given.
When the operation instructing unit 5233 recognizes that the charging time (period) Tc has elapsed based on the information from the time determining unit 5231, the charge signal CHG is set to the inactive level in order to drive and control the magnetic field generating unit 51 to the resonance state. The driver 524 is instructed to switch to the low level.
The operation instruction unit 5233 recognizes that the resonance time Tr has elapsed based on the information from the time determination unit 5231, and the current flowing through the coil L51 changes from the second direction current IL2 to the first direction current according to the determination result of the current direction determination unit 5232. When it is confirmed that the charge signal has turned to IL1, the driver 524 is instructed to output the charge signal CHG at an active high level.
When the operation instructing unit 5233 recognizes that the resonance time Tr has elapsed and the monitoring time Tm has further elapsed based on the information from the time determination unit 5231, the operation instructing unit 5233 forcibly outputs the charge signal CHG to the driver 524 at an active high level. Instruct to output.

The first configuration example of the drive control circuit 52 of the present embodiment has been described above.
The drive control circuit 52 of the present embodiment can adopt the following second configuration example in addition to the function of the first configuration example or separately from the first configuration example. .

[Second Configuration Example of Drive Control Circuit]
In the second configuration example, the drive control circuit 52 causes the current flowing in the coil L51 to flow in the first direction according to the monitoring result of the current direction monitoring circuit 53 within the preset charging time (period) Tc after the start of charging. When the current is changed to the current IL1, the resonance is started after the charging period is ended, and when the current flowing through the coil L51 is not changed to the first direction current IL1 within the charging time (period) Tc, It is also possible to terminate the drive control of the magnetic field generation unit as an abnormality.
As a result, the magnetic field generator 50 can perform charging and resonance in a normal state.

Further, the drive control circuit 52 acquires the number of times of reversal of the current flowing through the coil L51 according to the monitoring result of the current direction monitoring circuit 53 within the resonance time (period) Tc set in advance after the resonance starts, and the acquired inversion. When the number of times N is equal to or greater than the specified number of times Nc, drive control of the magnetic field generation unit 51 is performed according to the current flowing through the coil L51 according to the monitoring result of the current direction monitoring circuit 53 within the preset monitoring time Tm.
Specifically, as in the case of the first configuration example, the drive control circuit 52 causes the current direction to change when the preset resonance time Tr elapses after the charging is stopped (after the charging period elapses). Based on the monitoring result of the monitoring circuit 53, it is confirmed that the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1, and the drive control is performed so as to charge the magnetic field generation unit 51.
That is, when charging the magnetic field generation unit 51, the drive control circuit 52 outputs the charge signal CHG to the magnetic field generation unit 51 at an active level, for example, a high level, for a predetermined charging time Tc set in advance.
Thereby, the magnetic field generation device 50 can realize the optimization of the timing at which the direct current is passed through the capacitor of the resonance circuit to store the electric charges with higher accuracy.

Further, if the acquired number N of inversions does not reach the specified number Nc within the resonance period Tc, the drive control circuit 62 determines that there is an abnormality and ends the drive control of the magnetic field generation unit.
Further, when the preset monitoring time Tm has elapsed and the current flowing through the coil L51 does not turn into the first direction current, the drive control circuit 62 does not perform drive control so as to charge the magnetic field generation unit, and an abnormal magnetic field is generated. The drive control of the unit ends.
As a result, the magnetic field generator 50 performs drive control of charging and resonance in a normal state, that is, when it is determined that the direction of the current flowing through the coil L51 during charging or resonance is properly changing. You can

FIG. 5 is a block diagram showing a second configuration example of the drive control circuit according to the present embodiment.
The drive control circuit 52B of FIG. 5 differs from the drive control circuit 52A of FIG. 4 in the following points.

The storage unit 521B stores, in addition to various data of a preset charging time (period) Tc, resonance time (period) Tr, and monitoring time (period) Tm, a prescribed number Nc of current direction reversals. .
Various data of the charge time (period) Tc, the resonance time (period) Tr, and the monitoring time (period) Tm stored in the storage unit 521B are referred to by the time determination unit 5231 of the determination unit 523.
The specified number of times Nc stored in the storage unit 521B is referred to by the current direction determination unit 5232B.

The charging time Tc and the resonance time Tr are arbitrarily determined by the method of controlling the disturbing magnetic field. For example, the charging time Tc is set to 100 μs to 700 μs, and the resonance time Tr is set to 1000 μs to 2000 μs.
Also, the monitoring time Tm is arbitrarily determined based on the resonance cycle (1 / resonance frequency) of the parallel resonance circuit. The monitoring time Tm is set to 100 μs to 200 μs, for example.

When the current direction determination unit 5232B receives the information indicating that it is within the charging time Tc, the current direction determination unit 5232B determines whether or not the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1. It is supplied to the operation instruction unit 5233B.
When the current direction determination unit 5232B receives the information indicating that it is within the resonance time Tr, the current direction rotation is performed while switching the coil current direction flag FLG between "0" and "1" within the resonance time (period) Tr. The number N is counted and the result is supplied to the operation instruction unit 5233B.
Upon receiving the information indicating that the resonance time Tr has elapsed, the current direction determination unit 5232B determines whether or not the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1. It is supplied to the operation instruction unit 5233B.

When the disturbing magnetic field is generated, the operation instructing unit 5233B first instructs the driver 524 to output the charge signal CHG at an active high level in order to start charging.
The operation instruction unit 5233B notifies the time determination unit 5231 and the current direction determination unit 5232 that the charge start instruction has been issued.
When the current flowing through the coil L51 is the first direction current IL1 according to the monitoring result of the current direction monitoring circuit 53 within the charging time Tc, the operation instructing unit 5233B drives and controls the magnetic field generation unit 51 to the resonance state. Then, the driver 524 is instructed to switch the charge signal CHG to the inactive low level when the charge time Tc has elapsed.
If the current flowing through the coil L51 does not become the first direction current IL1 (does not change) within the charging time Tc, the operation instructing unit 5233B determines that there is an abnormality and ends the drive control of the magnetic field generating unit.
When the operation instruction unit 5233B recognizes that the charging time Tc has elapsed based on the information from the time determination unit 5231, the charge signal CHG is set to the inactive low level in order to drive and control the magnetic field generation unit 51 to the resonance state. The driver 524 is instructed to switch.
When the acquired inversion number N is equal to or greater than the specified number Nc within the resonance time Tr, the operation instructing unit 5233B recognizes that the resonance time Tr has elapsed based on the information from the time determination unit 5231, and determines the current direction. When it is confirmed that the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1 according to the determination result of the unit 5232B, the charge signal CHG is output to the driver 524 at the active level high level. Give instructions.
The operation instructing unit 5233B determines that the current flowing through the coil L51 does not reach the first value even when the acquired inversion number N does not reach the specified number Nc within the resonance time Tr or when the monitoring time Tm has elapsed according to the information from the time determination unit 5231. When the two-direction current IL2 does not change to the first-direction current IL1, the drive control of the magnetic field generation unit is terminated as an abnormality.

  Although the first configuration example and the second configuration example of the drive control circuit 52 of the present embodiment have been described above, the operation examples of the first configuration example and the second configuration example will be associated with the flowchart later. Explain.

[Example of arrangement of magnetic field generator]
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 controller 40. When an electric current is applied, a disturbing magnetic field is generated and arranged in the opening 21 or the outer portion of the card insertion portion 31. The region where the disturbing magnetic field is generated is configured to include a passage region of the magnetic stripe mp formed on the magnetic card MC that is inserted or ejected through the card insertion portion 31.

As shown in FIG. 1, the magnetic field generation device 50 having the above configuration has a magnetic field generation unit 51, a drive control circuit 52, and a current direction monitoring circuit near the inner side (back side) of the front panel 20, as shown in FIG. 53 can be arranged to include the entire circuit.
However, for example, a resonance part as a magnetic field generation part 51 composed of a coil (inductor) L51 and a capacitor C51 is arranged near the inside of the front panel 20, and the remaining circuit system is arranged at another position, for example, the control part 40 side. Various modes such as arrangement are possible.

  FIG. 6 is a diagram schematically showing a state in which a magnetic head for skimming (including a skimmer) is attached to the outside of the apparatus.

  In the card reader 10, when inserting the card MC, the leading end of the card MC is inserted into the card insertion port 311 and at the same time, the card MC is conveyed by the conveying roller 331 at a constant speed. Similarly, when the magnetic card MC is ejected, the magnetic card MC is conveyed at a constant speed by the conveying roller 331 until it is substantially ejected from the card insertion slot 311 to the outside.

  Therefore, when a skimming magnetic head and a skimmer including a magnetic reading circuit (a device that illegally reads the data of the magnetic card) are attached to the outside of the card insertion slot 311, a constant speed is maintained along the skimming magnetic head. Will move the card. Therefore, the data recorded on the card can be read by the 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. 6, a skimmer 60 including a magnetic head 61 for skimming is illegally attached to the surface of the front panel 20 in which a card slot opening 21 is formed. Even in this case, the reading operation of the card MC by the skimming magnetic head 61 can be blocked by the disturbing magnetic field generated by the magnetic field generator 50.

That is, in the magnetic field generator 50 of the present embodiment, it is possible to continue the generation of the disturbing magnetic field, and by monitoring the direction of the alternating current flowing through the coil that is the inductor, the direct current is applied to the capacitor C51 of the parallel resonant circuit. It is possible to optimize the timing at which an electric current is supplied to store electric charges, and it is possible to perform an energy-efficient interfering magnetic field control.
Further, in the magnetic field generation device 50, by constantly monitoring the current state of the coil which is the inductor, it is possible to detect damage to the resonance circuit element or malfunction due to disconnection of the coil, and as a disturbance magnetic field generation device. The reliability of can be improved.
Further, in the magnetic field generation device 50, the current direction monitoring circuit 43 can be realized by adding a comparator (comparator) circuit element.
Next, a more specific configuration and function of the magnetic field generation device 50 having such characteristic effects will be described.

[Configuration Example of Magnetic Field Generating Unit 51 of Magnetic Field Generating Device 50, Drive Control Circuit 52, Current Direction Monitoring Circuit 53]
Next, specific circuit configurations and operations of the magnetic field generator 51, the drive control circuit 52, and the current direction monitoring circuit 53 of the magnetic field generator 50 will be described in detail as an embodiment. In the following description, as for the drive control circuit 52, a drive circuit system excluding the configurations of FIGS. 4 and 5 will be described.
In the following description, the resonance unit 511, which constitutes the magnetic field generation unit 51 of the magnetic field generation device 50 according to the present embodiment described with reference to FIG. 7, basically connects the coil L, which is an inductor, and the capacitor C. It has a formed LC parallel resonance circuit, and has a function of continuously generating a magnetic field by the LC parallel resonance circuit.

  Further, in the present embodiment, the magnetic field generation unit 51 has a function of generating a stronger magnetic field than the conventional coil-only circuit by the LC parallel resonance circuit. As a result, the magnetic field generator 50 can increase the output of the disturbing magnetic field, continuously generate the disturbing magnetic field for a predetermined period, and continuously generate the disturbing magnetic field with an appropriate time and intensity. It is possible to reliably prevent illegal acquisition of magnetic data using the skimming magnetic head.

Further, in the present embodiment, the charging timing of the magnetic field generation unit 51 is controlled according to the direction of the current flowing through the coil L51 obtained by the monitoring of the current direction monitoring circuit 53.
As described above, in the present embodiment, in the magnetic field generation device 50, the direction of the alternating current flowing through the coil L51 is monitored, thereby optimizing the timing at which the direct current is passed through the capacitor C51 of the parallel resonant circuit to store the electric charge. Can be achieved.
Therefore, it is possible to control the disturbing magnetic field with high accuracy and efficiency, and it is possible to reliably prevent illegal acquisition of magnetic data by using the skimming magnetic head.
Further, in the magnetic field generation device 50, by constantly monitoring the current state of the coil which is the inductor, it is possible to detect damage to the resonance circuit element or malfunction due to disconnection of the coil, and as a disturbance magnetic field generation device. The reliability of can be improved.

[Embodiment of magnetic field generator]
Next, the configuration of the magnetic field generator and the like of the magnetic field generator according to the present embodiment will be described.
FIG. 7 is a circuit diagram showing a magnetic field generator, a drive control circuit, and a current direction monitoring circuit of the magnetic field generator according to the present embodiment of the present invention.

  The magnetic field generation device 50C of FIG. 7 basically includes a resonance unit 511 that constitutes the magnetic field generation unit 51C, a drive power supply unit (power supply circuit) 525 that supplies a drive power supply voltage VCC as the drive control circuit 52C, and a reference potential unit 526. , A resonance drive unit 527, and a current direction monitoring circuit 53C.

In this embodiment, the VCC supplied by the drive power supply unit 525 (hereinafter referred to as drive voltage) is set to 24V or 20V. The drive power supply unit 525 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 as a power supply circuit.
In the driving power supply unit 525, 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 to 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 part 526 is set to the reference potential VSS. In this embodiment, the reference potential is the ground potential GND.

The resonance unit 511 is configured to include a parallel resonance circuit in which a coil L51, which is an inductor, and a capacitor C51 are connected in parallel between the first node ND52 and the second node ND53.
The resonance part 511 receives the drive voltage VCC at the first node ND52, electrically connects the second node ND53 to the reference potential part 526, and then resonates in the state where the reference potential part 526 is electrically disconnected. Then, a magnetic field corresponding to the current flowing through the coil L51 is generated.
That is, the resonance unit 511 is configured to generate an interfering magnetic field in the skimming magnetic head to prevent illegal acquisition of magnetic data.

In the present embodiment, the resonance circuit is 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, as shown in FIG. 7 as an example. Has been done.
One end TP1 of the coil L51, which is an inductor, is connected to the first node ND52, and the other end TP2 of the coil L51 is connected to the second node ND53. One electrode (terminal) of the capacitor C51 is connected to the first node ND52, and the other electrode (terminal) thereof is connected to the second node ND53.
The first node ND52 is connected to the supply line of the drive voltage VCC of the drive power supply unit 525. The second node ND53 is selectively connected to the reference potential unit 526 via the high power drive switching element DSW51 of the resonance drive unit 527.

In the LC parallel resonance circuit, the currents of the LCs cancel each other out, and the impedance looks infinite at the resonance frequency from the outside. At this time, the energy stored as an electric field inside the capacitor C51 and the energy stored as a magnetic field inside the coil L51 which is an inductor move to each other inside the parallel resonant circuit.
In the present embodiment, the resonance unit 511 is controlled through the resonance driving unit 527 so as to periodically and continuously resonate by the charge signal CHG which is a pulsed control signal.

The pulse-shaped charge signal CHG is a current flowing through the coil L51 according to the monitoring result of the current direction monitoring circuit 53C when the preset resonance time Tr elapses after the charging is stopped (after the charging period elapses). When it is confirmed that the current has changed from the second direction current IL2 to the first direction current IL1, the drive control is performed so as to charge the resonance unit 511 that is the magnetic field generation unit 51.
In the present embodiment, when charging the resonance unit 511 of the magnetic field generation unit 51, the charge signal CHG is supplied at an active level, for example, a high level, for a predetermined charging time Tc set in advance.

The resonance unit 511 is controlled so that resonance is induced and a magnetic field is generated by switching the connection state and the non-connection state between the second node ND53 and the reference potential unit 526 through the resonance drive unit 527.
Further, the resonance unit 511 is such that the magnetic field generated after the card MC is inserted into the card insertion port 311 through the resonance drive unit 527 and the card width sensor 371 detects the card MC does not maintain the function as the disturbing magnetic field. Or until the generated magnetic field disappears, control is performed (magnetic field generation stop control) so as not to generate an interfering magnetic field for a time longer than the above-described period. The control unit 40 determines whether or not magnetism is detected by the pre-head 39 during a predetermined period when the generation of the disturbing magnetic field is stopped.

  The term “cycle” here means that after the resonance action is induced and a magnetic field is generated, the magnetic field is attenuated along with the attenuation of the resonance energy accumulated in the resonance part. The period during which the resonance can be induced.

The resonance drive unit 527 switches the connection state and the non-connection state between the second node ND53 of the resonance unit 511 and the reference potential unit 526 according to the charge signal CHG from the control unit 40 (driver 524 of the drive control circuit 52). As a result, resonance is induced and control is performed so as to generate a magnetic field.
In addition, the resonance driving unit 527 is generated by the second node ND53 of the resonance unit 511 and the reference potential unit 526 being periodically or / and aperiodically switched to the non-connection state according to the charge signal CHG. The generated magnetic field is controlled so as not to generate the disturbing magnetic field for a time longer than the above-described period in which the function as the disturbing magnetic field cannot be maintained.

The resonance drive unit 527 of the present embodiment is configured to include a high power drive switching element DSW51 formed of a transistor such as a bipolar transistor.
In the example of FIG. 7, the drive switching element DSW51 is formed by an npn-type bipolar switch, the collector is connected to the second node ND53 of the resonance section 511, the emitter is connected to the reference potential section 526, and the base is the charge signal. It is connected to the CHG supply line.

  In this way, the drive switching element DSW51 is connected between the second node ND53 of the resonance unit 511 and the reference potential unit 526, and is switched between the conductive state and the non-conductive state according to the charge signal CHG, and the resonance unit 511. The connection state and the non-connection state between the second node ND53 and the reference potential portion 526 are switched.

  Resonance drive unit 527 drives drive switching element DSW51 into a conductive state when receiving charge signal CHG at an active high level, for example. When receiving the charge signal CHG at the inactive low level, the resonance drive unit 527 drives the drive switching element DSW51 to the non-conduction state.

[Example of current direction monitoring circuit configuration]
Here, a specific configuration example of the current direction monitoring circuit 53C that monitors the direction of the current flowing through the coil L51 that configures the resonance unit 511 will be described.

The current direction monitoring circuit 53C detects the potentials of both ends TP1 and TP2 of the coil L51, compares the potentials thereof, and outputs the comparison output signal DIR to drive control as shown in FIGS. 3, 4 and 5. Output to the circuit 52 (52A, 52B).
In the present embodiment, the current direction monitoring circuit 53C outputs the comparison output signal DIR at a low level (L), for example, when the potential on the one end TP1 side of the coil L51 is higher than the potential on the other end TP2 side. Output to.
On the other hand, the current direction monitoring circuit 53C controls the comparison output signal DIR at a high level (H), for example, when the potential on the one end TP1 side of the coil L51 is lower than (or below) the potential on the other end TP2 side. Output to the circuit 52.

The current direction monitoring circuit 53C has resistance elements R51, R52, R53, R54 and a comparator 531 as shown in FIG.
The resistance elements R51 and R52 are connected in series between one end TP1 of the coil L51 of the resonance part 511 and the reference potential part 526. A connection node ND531 of the resistance elements R51 and R52 connected in series is connected to the inverting input terminal (−) of the comparator 531.
The resistance elements R53 and R54 are connected in series between the other end TP2 of the coil L51 of the resonance section 511 and the reference potential section 526. The connection node ND532 of the resistance elements R53 and R54 connected in series is connected to the non-inverting input terminal (+) of the comparator 531.

The comparator 531 compares the potential of the connection node ND531 and the potential of the connection node ND532, that is, the potential on the one end TP1 side of the coil L51 and the potential on the other end TP2 side.
The comparator 531 outputs the comparison output signal DIR to the drive control circuit 52 at a low level (L), for example, when the potential on the one end TP1 side of the coil L51 is higher than the potential on the other end TP2 side.
The comparator 531 outputs the comparison output signal DIR to the drive control circuit 52 at a high level (H), for example, when the potential on the one end TP1 side of the coil L51 is lower than (or below) the potential on the other end TP2 side. .

The drive control circuit 52 as shown in FIGS. 3, 4 and 5 receives the comparison output signal DIR of the comparator 531 and controls the charging timing of the magnetic field generation unit 51.
As described above, the drive control circuit 52 causes the current flowing in the coil L51 to change from the second direction current IL2 to the first direction current IL1, so that, for example, the current flowing in the coil L51 changes from the second direction current IL2 to the first direction current IL2. The drive control is performed so as to charge the magnetic field generation unit 51 at the timing when the current is switched to the current IL1.
As a result, the magnetic field generation device 50 realizes, with high accuracy, the timing of accumulating charges by flowing a direct current through the capacitor of the resonance circuit.

Next, the operation of the magnetic field generator 50C according to the present embodiment will be described with reference to FIGS. 8, 9, and 10.
FIG. 8 is a waveform diagram for explaining the operation of the magnetic field generator according to the present embodiment. FIG. 8 shows waveforms when the magnetic field generator 50C of FIG. 7 is mounted on the card reader 10 of FIG. 8A shows the charge signal CHG, FIG. 8B shows the coil current IL (1, 2), FIG. 8C shows the power supply current ICS, and FIG. 8D shows the head output. A certain disturbing magnetic field DMG is shown, and FIG. 8 (e) shows the comparison output signal DIR.
Further, FIG. 9 is a flowchart for explaining the operation when the first configuration example of FIG. 4 is adopted as the drive control circuit.
FIG. 10 is a flowchart for explaining the operation when the second configuration example of FIG. 5 is adopted as the drive control circuit.

[Example of operation when the drive control circuit of the first configuration example is adopted]
First, the operation when the first configuration example of FIG. 4 is adopted as the drive control circuit will be described with reference to FIGS. 8 and 9.

First, in a state where no disturbing magnetic field is generated, as shown in FIG. 8A, the charge signal CHG is supplied from the driver 524 of the drive control circuit 52 of the controller 40 to the magnetic field generator 50C so as to generate the disturbing magnetic field. Is supplied to the resonance drive unit 527 of the drive control circuit 52A.
In this case, the charge signal CHG is supplied at the active high level (H). In the resonance drive section 527, when the charge signal CHG is received at the active high level, the drive switching element DSW51 is driven to the conductive state.
As a result, charging is started (step ST1 in FIG. 9).
At this time, the time determination unit 5231 of the drive control circuit 52A stores the current time CTM1 at the charging start time, which is supplied from the clock unit 522 at the time when the charging is started, in a memory (not shown) (step ST2 in FIG. 9). ).

In the resonance part 511, the second node ND53 is electrically connected to the reference potential part 526. In the resonance unit 511, the drive voltage VCC is supplied from the drive power supply unit 525 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 526 through the resonance drive unit 527, so that the charge to the capacitor C51 is started and the resonance function is induced, so that the resonance function of FIG. As shown in (b), the positive first current IL1 flowing through the coil (inductor) L51 is controlled to increase and generate a disturbing magnetic field.

Here, in the time determination unit 5231 of the drive control circuit 52A, it is determined whether or not the difference between the current time CTM2 and the time TMC1 at the charge start time stored in step ST2 exceeds a predetermined charge time Tc (FIG. 9, step ST3), and the result is supplied to the operation instructing unit 5233.
When the operation instructing unit 5233 recognizes that the predetermined charging time Tc has elapsed from the start of charging based on the determination result of the time determining unit 5231 (step ST3 in FIG. 9), the operation instructing unit 5233 drives and controls the magnetic field generation unit 51 to the resonance state. Therefore, the driver 524 is instructed to switch the charge signal CHG to the low level of the inactive level.
As a result, the charge signal CHG is switched to the inactive low level (L) and supplied to the resonance drive unit 527. In the resonance drive section 527, when the charge signal CHG is received at the inactive low level, the drive switching element DSW51 is driven to the non-conduction state.
Along with this, charging stops and resonance starts (step ST4 in FIG. 9).
In addition, when the current flowing through the coil (inductor) L51 is changed to the positive first direction current IL1 according to the determination result of the time determination unit 5231 within the charge time Tc, the operation instruction unit 5233 determines that the charge time Tc is Resonance starts after the end.

  At this time, the time determination unit 5231 of the drive control circuit 52A stores the current time CTM3 at the resonance start time, which is supplied from the clock unit 522 at the time when the resonance is started, in a memory (not shown) (step ST5 in FIG. 9). ).

Here, the time determination unit 5231 of the drive control circuit 52A determines whether the difference between the current time CTM4 and the time TMC3 stored in step ST5 exceeds a predetermined resonance time Tr (step ST6 in FIG. 9). ), And the result is supplied to the operation instruction unit 5233.
When the operation instructing unit 5233 recognizes that the predetermined resonance time Tr has elapsed from the start of resonance based on the determination result of the time determination unit 5231 (step ST6 in FIG. 9), the clock unit 522 at the time when the resonance time Tr has elapsed. The current time CTM5 supplied from the memory is stored in a memory (not shown) (step ST7 in FIG. 9).

Then, the operation instructing unit 5233 confirms that the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1 according to the determination result of the current direction determining unit 5232 (step ST8 in FIG. 9).
When it is confirmed in step ST8 that the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1, the driver 524 is instructed to output the charge signal CHG at the active level of high level. .
In this case, the process returns to step ST1, and the charge signal CHG is supplied at the active high level (H). In the resonance drive section 527, when the charge signal CHG is received at the active high level, the drive switching element DSW51 is driven to the conductive state.

In the resonance part 511, the second node ND53 is electrically connected to the reference potential part 526. In the resonance unit 511, the drive voltage VCC is supplied from the drive power supply unit 525 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 526 through the resonance drive unit 527, so that the charge to the capacitor C51 is started and the resonance function is induced, so that the resonance function of FIG. As shown in (b), the first current IL1 in the forward direction flowing through the coil (inductor) L51 is controlled to increase and generate a magnetic field.
That is, since the charging is restarted at the timing when the current flowing through the coil L51 switches to the positive direction (first current direction), the disturbing magnetic field with good charging efficiency is generated.

If it cannot be confirmed in step ST8 that the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1, the time determination unit 5231 of the drive control circuit 52A determines the current time CTM6 and step ST7. It is determined whether or not the difference from the stored time TMC5 exceeds a predetermined monitoring time Tm (step ST9 in FIG. 9), and the result is supplied to the operation instructing unit 5233.
The operation instructing unit 5233 repeats the process of step 8 until the predetermined monitoring time Tr elapses after the resonance is started according to the determination result of the time determining unit 5231.
On the other hand, when the operation instructing unit 5233 recognizes that the predetermined monitoring time Tm has elapsed from the start of resonance based on the determination result of the time determining unit 5231 (step ST9 in FIG. 9), it forces the driver 524. It is instructed to output the charge signal CHG at the active level of high level.
That is, also in this case, the processing from step ST1 is repeated.

  At the time of resonance, the second node ND53 of the resonance part 511 is electrically separated from the reference potential part 526, but the resonance part 511 is induced by the resonance energy and the current IL of the coil (inductor) L51 is reduced. Flows while being attenuated, and along with this, the generation of the disturbing magnetic field is continued while being attenuated.

  Here, the drive control circuit 52A of the control unit 40 supplies, for example, a pulsed charge signal CHG to the resonance drive unit 527, so that the resonance action is induced in the resonance unit 511 and a magnetic field is generated. The magnetic field decays with the decay. However, the control unit 40 has a constant period and / or aperiodic period from the previous output (supply) so that resonance can be induced while the function of the decaying magnetic field is maintained as the disturbing magnetic field. The charge signal CHG is (randomly) supplied to the resonance drive unit 527 at an active high level (H).

  That is, as described above, as shown in FIGS. 8A to 8D, the charge signal CHG is active from the control unit 40 to the resonance drive unit 527 of the drive control circuit 52A so as to generate the magnetic field again. It is supplied at high level (H). In the resonance drive section 527, when the charge signal CHG is received at the active high level, the drive switching element DSW51 is driven to the conductive state.

  As a result, in the resonance part 511, the second node ND53 is electrically connected to the reference potential part 526. In the resonance unit 511, the drive voltage VCC is supplied from the drive power supply unit 525 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 526 through the resonance drive unit 527, so that the resonance function is induced again and the current flowing through the coil (inductor) L51 increases. And controlled to generate a magnetic field.

  Here, the pulsed charge signal CHG is switched to the inactive low level (L) and is supplied to the resonance drive unit 527. In the resonance drive section 527, when the charge signal CHG is received at the inactive low level, the drive switching element DSW51 is driven to the non-conduction state.

  At this time, the second node ND53 of the resonance part 511 is electrically disconnected from the reference potential part 526, but the resonance part 511 flows while the current of the coil (inductor) L51 attenuates due to the induced resonance energy. Along with this, the generation of the disturbing magnetic field is continued while being attenuated.

  The above operation is repeated 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 50C of the present embodiment, magnetic data is read by generating an interfering magnetic field with respect to the skimming magnetic head that is illegally attached to the card insertion slot 311. Can be prevented.

By the way, in the card reader 10 equipped with the magnetic field generator 50C of the present embodiment, when the disturbing magnetic field is generated by the resonance unit (parallel resonance circuit) 511, the card is detected by the card width sensor 371 as the card detection sensor. If detected, it is necessary to stop the generation of the disturbing magnetic field because it is necessary to detect the magnetism by the pre-head 39.
Therefore, in the card reader 10 equipped with the magnetic field generator 50C, the control unit 40 periodically or / and aperiodically stops the generation of the disturbing magnetic field by using the detection of the card by the card width sensor 371 as a trigger. The output of the charge control signal CHG from the drive control circuit 52C to the resonance drive section 527 is stopped.

[Operation example when the drive control circuit of the second configuration example is adopted]
Next, the operation when the second configuration example of FIG. 5 is adopted as the drive control circuit will be described with reference to FIGS. 8 and 10.

First, in a state where no disturbing magnetic field is generated, as shown in FIG. 8A, the charge signal CHG is supplied from the driver 524 of the drive control circuit 52 of the controller 40 to the magnetic field generator 50C so as to generate the disturbing magnetic field. Is supplied to the resonance drive unit 527 of the drive control circuit 52C.
In this case, the charge signal CHG is supplied at the active high level (H). In the resonance drive section 527, when the charge signal CHG is received at the active high level, the drive switching element DSW51 is driven to the conductive state.
As a result, charging is started (step ST11 in FIG. 10).
At this time, the time determination unit 5231 of the drive control circuit 52B stores the current time CTM11 at the charging start time, which is supplied from the clock unit 522 at the time when the charging is started, in a memory (not shown) (step ST12 in FIG. 10). ).

In the resonance part 511, the second node ND53 is electrically connected to the reference potential part 526. In the resonance unit 511, the drive voltage VCC is supplied from the drive power supply unit 525 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 526 through the resonance drive unit 527, so that the charge to the capacitor C51 is started and the resonance function is induced, so that the resonance function of FIG. As shown in (b), the positive first current IL1 flowing through the coil (inductor) L51 is controlled to increase and generate a disturbing magnetic field.

Here, the operation instructing unit 5233B of the drive control circuit 52B confirms whether or not the current flowing through the coil L51 is the first direction current IL1 according to the determination result of the current direction determining unit 5232B (step ST13 in FIG. 10).
When the current flowing through the coil L51 is the first direction current IL1 according to the monitoring result of the current direction monitoring circuit 53C within the charging time Tc, the operation instructing unit 5233B drives and controls the magnetic field generation unit 51 to the resonance state. Then, it is confirmed whether or not the charging time Tc has elapsed (step ST14 in FIG. 10).
Specifically, the time determination unit 5231 of the drive control circuit 52B determines whether the difference between the current time CTM12 and the time TMC11 at the charge start time stored in step ST12 exceeds a predetermined charge period Tc. (Step ST14 of FIG. 10), and the result is supplied to the operation instruction unit 5233B.
When the operation instruction unit 5233B recognizes that the predetermined charging time Tc has elapsed from the start of charging based on the determination result of the time determination unit 5231 (step ST14 in FIG. 10), it drives and controls the magnetic field generation unit 51 to the resonance state. Therefore, the driver 524 is instructed to switch the charge signal CHG to the low level of the inactive level.
As a result, the charge signal CHG is switched to the inactive low level (L) and supplied to the resonance drive unit 527. In the resonance drive section 527, when the charge signal CHG is received at the inactive low level, the drive switching element DSW51 is driven to the non-conduction state.
Along with this, charging stops and resonance starts (step ST15 in FIG. 10).
In addition, when the current flowing through the coil (inductor) L51 is changed to the positive first direction current IL1 according to the determination result of the time determination unit 5231 within the charge time Tc, the operation instruction unit 5233 determines that the charge time Tc is Resonance starts after the end.

  In step ST13, if the current flowing through the coil L51 does not become the first direction current IL1 (if it does not change) within the charging time Tc, the drive control circuit 52B determines that there is an abnormality and ends the drive control of the magnetic field generation unit. .

When the resonance is started in step ST15, the time determination unit 5231 of the drive control circuit 52B stores the current time CTM13 at the resonance start time supplied from the clock unit 522 at the time when the resonance is started in a memory (not shown). (Step ST16 of FIG. 10).
Next, the current direction determination unit 5232B of the drive control circuit 52B sets the current direction flag FLG to, for example, "1" (or "0") and sets the current direction inversion count N to "0" (see FIG. 10). Step ST17). That is, the current direction determination unit 5232B initializes the current direction flag FLG and the current direction inversion number N.
Next, the current direction determination unit 5232B determines whether or not the direction of the current flowing through the coil L51 matches the direction indicated by the set current direction flag FLG based on the comparison output signal DIR from the current direction monitoring circuit 53C. (Step ST18 of FIG. 10).
In step ST18, when it is determined that they match, the process proceeds to step ST19, and when it is determined that they do not match, the process of step ST19 is not performed and the process proceeds to step ST20.
In step ST19, the set value of the current direction flag FLG is set to an exclusive OR (XOR) value, for example, "0", and the current direction inversion number N is incremented by one. Then, the process proceeds to step ST20.

In step ST20, the time determination unit 5231 of the drive control circuit 52B determines whether or not the difference between the current time CTM14 and the time TMC13 at the resonance start time stored in step ST16 exceeds a predetermined resonance time Tr. The result is supplied to the operation instructing unit 5233.
When the operation instructing unit 5233 recognizes that the predetermined resonance time Tr has elapsed from the start of resonance based on the determination result of the time determination unit 5231 (step ST20 in FIG. 10), the operation instructing unit 5233 proceeds to the process of step ST21 and has elapsed. If not, the process returns to step ST18, and the current direction flag FLG is set and the current direction reversal number N is counted (incremented) until the resonance time Tr elapses.
In step ST21, the current direction determination unit 5232B of the drive control circuit 52B determines whether or not the counted current direction reversal number N is equal to or greater than the specified number Nc stored in the storage unit 521B. Is supplied to the operation instructing unit 5233B.
When the operation instruction unit 5233B confirms that the counted current direction reversal number N is equal to or greater than the specified number Nc, the operation instruction unit 5233B issues an instruction to the time determination unit 5231.
As a result, the time determination unit 5231 of the drive control circuit 52B stores the current time CTM15 at the resonance elapsed time, which is supplied from the clock unit 522 at the time when the resonance time has elapsed, in a memory (not shown) (step ST22 in FIG. 10). ).

Then, the operation instructing unit 5233B confirms that the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1 according to the determination result of the current direction determining unit 5232B (step ST23 in FIG. 10).
When it is confirmed in step ST23 that the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1 (step ST23 in FIG. 10), the charge signal CHG is set to the active level high level for the driver 524. Instruct to output.
In this case, the process returns to step ST11, and the charge signal CHG is supplied at the active high level (H). In the resonance drive section 527, when the charge signal CHG is received at the active high level, the drive switching element DSW51 is driven to the conductive state.

In the resonance part 511, the second node ND53 is electrically connected to the reference potential part 526. In the resonance unit 511, the drive voltage VCC is supplied from the drive power supply unit 525 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 526 through the resonance drive unit 527, so that the charge to the capacitor C51 is started and the resonance function is induced, so that the resonance function of FIG. As shown in (b), the positive first current IL1 flowing through the coil (inductor) L51 is controlled to increase and generate a disturbing magnetic field.
That is, since the charging is restarted at the timing when the current flowing through the coil L51 switches to the positive direction (first current direction), the disturbing magnetic field with good charging efficiency is generated.
That is, also in this case, the processing from step ST11 is repeated.

If it cannot be confirmed in step ST23 that the current flowing through the coil L51 has changed from the second direction current IL2 to the first direction current IL1, the time determination unit 5231 of the drive control circuit 52B determines the current time CTM16 and step ST22. It is determined whether the difference between the stored time TMC15 at the end of resonance and the predetermined monitoring time Tm has exceeded (step ST24 in FIG. 10), and the result is supplied to the operation instructing unit 5233B.
The operation instructing unit 5233B repeats the process of step 23 until the predetermined monitoring time Tm elapses after the resonance is started according to the determination result of the time determination unit 5231.

  On the other hand, when the acquired inversion number N does not reach the specified number Nc within the resonance time Tc in step ST21, the operation instructing unit 5233B determines that the monitoring time Tm has elapsed according to the information from the time determination unit 5231 in step ST24. Also, if the current flowing through the coil L51 does not change from the second direction current IL2 to the first direction current IL1, the drive control of the magnetic field generation unit is terminated as an abnormality.

As described above, in the present embodiment, the charging timing of the magnetic field generation unit 51 is controlled according to the direction of the current flowing through the coil L51 obtained by monitoring the current direction monitoring circuit 53C.
That is, in the present embodiment, in the magnetic field generator 50, by monitoring the direction of the alternating current flowing in the coil L51 and / or monitoring the number of current direction reversals, a direct current is passed through the capacitor C51 of the parallel resonant circuit. It is possible to optimize the timing of storing electric charges.
Therefore, it is possible to control the disturbing magnetic field with high accuracy and efficiency, and it is possible to reliably prevent illegal acquisition of magnetic data by using the skimming magnetic head.
Further, in the magnetic field generation device 50, by constantly monitoring the current state of the coil which is the inductor, the drive control of the magnetic field generation unit is terminated as damage or abnormality of the resonance circuit element.
Further, in the magnetic field generator 50, by constantly monitoring the current state of the coil, it is possible to detect the malfunction of the resonance circuit element or the disconnection of the coil, which results in the reliability of the disturbance magnetic field generator. It is possible to improve.
Further, the current direction monitoring circuit 53 has an advantage that it can be realized by adding a comparator (comparator) circuit element.

Here, as a comparative example, the charge and resonance operation when the monitoring of the direction of the current flowing through the coil L51 and / or the monitoring of the number of current direction reversals is not performed as in the present embodiment will be considered.
FIG. 11 is a waveform diagram showing a state where the charging and resonance operations are normally performed when the current direction is not monitored.
FIG. 12 is a waveform diagram showing a state in which the charging and resonance operations are not normally performed when the current direction is not monitored.
11 and 12, (a) shows the charge signal CHG, FIG. 8 (b) shows the coil current IL (1, 2), (c) shows the power supply current ICS, and (d) shows the disturbing magnetic field. The disturbing magnetic field DMG, which is the generator output, is shown.

Even in the parallel resonance circuit of the magnetic field generator when the monitoring of the current direction is not performed, first, a direct current is applied to the capacitor to charge it to store an electric charge, and then the electricity stored in the capacitor is discharged to form a coil. Resonant operation is performed in which an alternating current is passed between the capacitors.
In this charging and resonance operation, if the next charging happens by chance when the current direction changes from the second direction current IL2 to the first direction current IL1, as shown in FIGS. 11 (a) and <b>, The charge can be properly stored in the capacitor.
As a result, the coil of the skimming head can be given a mutual induction action to disturb the output and interfere with the magnetic data exploitation.

  However, in the magnetic field generator 50, when charging and resonance are repeatedly performed continuously, as shown in FIGS. 12A to 12D, the timing when the coil current flows in the opposite direction during resonance (when the capacitor is If the charging is performed during discharge, the charging efficiency of the capacitor may be reduced and the interference output intensity to the skimming magnetic head may be reduced.

On the other hand, in the present embodiment, by monitoring the direction of the current flowing through the coil L51 and / or monitoring the number of current direction reversals, the timing at which a direct current is passed through the capacitor C51 of the parallel resonant circuit to store the charge. Can be optimized.
Therefore, it is possible to control the disturbing magnetic field with high accuracy and efficiency, and it is possible to reliably prevent illegal acquisition of magnetic data by using the skimming magnetic head.

When the magnetic field generator 50 having such characteristics is applied to the card reader 10, the magnetic field generation is temporarily stopped and the resonance part of the drive control circuit 52 is prevented so that the residual disturbing magnetic field does not affect the magnetic detection. It is also possible to adopt a configuration in which the resonance energy accumulated in 511 is released (discharged).
With this configuration, for example, in the magnetic field generation device 50, a transistor serving as a first switching element for discharging is connected to the first node ND52 of the resonance unit 511 to secure a resonance energy emission path (discharge path, escape path). To do.
Further, in the magnetic field generation device 50C, the supply line of the drive voltage VCC of the drive power supply unit 525 to the resonance unit 511 supplies the drive voltage VCC to the first node ND52 of the resonance unit 511 when the disturbing magnetic field generation operation is stopped. A transistor as a second switching element to be stopped is connected.
In this case, when the operation of generating the disturbing magnetic field is stopped, preferably, the second switching element is turned off to disconnect the first node ND52 from the supply source of the drive voltage VCC, and then the first switching element is turned on. Emit resonant energy.
On the other hand, at the start of the magnetic field generating operation, the first switching element is turned off to close the discharge path, and then the second switching element is turned on to connect to the supply source of the drive voltage VCC.

[Card loading / unloading operation of card reader]
Finally, as an example, the operation of taking in and ejecting the card MC of the card reader 10 will be described in association with the drive timing of the magnetic field generation device 50.
In the following description, regarding the generation of the magnetic field, the operation of monitoring the current direction, which has already been described in detail, is omitted, and it is simply described as generation of a disturbing magnetic field. In other words, the disturbing magnetic field generation step includes all of the charge start control operation and the like by monitoring the current direction described above, and the same process as in FIGS. 9 and 10 is performed in generating the disturbing magnetic field.

  First, the capturing operation will be described with reference to FIGS. 13 and 14. FIG. 13 is a flowchart for explaining the operation at the time of taking in a card. FIG. 14 is a diagram for explaining the operation when the card is loaded.

Here, under the control of the control unit 40, the drive control circuit 52 of the magnetic field generator 50 is driven to generate an interfering magnetic field for the skimming magnetic head (step ST31). The generation of the disturbing magnetic field is performed by the same processing as that shown in FIGS.
When the user inserts the card MC into the card insertion slot 311 with this disturbing magnetic field generated (step ST32), the inserted card is detected by the card width sensor 371 (step ST33). This detection information is supplied to the control unit 40.

When the insertion of the card MC is detected, the control unit 40 then causes the pre-head 39 to slide on the magnetic stripe mp formed on the card MC to read the magnetic data written on the magnetic stripe mp.
At this time, the control unit 40 generates the magnetic field in the same manner as the above-described operation so that the residual disturbing magnetic field does not affect the magnetic detection when the pre-head 39 reads the magnetic data of the card MC and the magnetic detection is performed. Is stopped, and the resonance energy accumulated in the resonance unit 511 of the drive control circuit 52 is released (discharged) (steps ST34 and ST35).
In this state, the magnetic stripe portion formed on the inserted card MC is detected by the card insertion detection pre-head 39 (step ST36). Then, in response to the detection signal from the pre-head 39, the control unit 40 drives the drive control circuit 52 of the magnetic field generator 50 for a predetermined time to generate a disturbing magnetic field (step ST37).
Then, in the state where the disturbing magnetic field is generated, the control unit 40 opens the shutter 38 (step ST8), activates the drive motor 36 (step ST39), and drives the carrying system including the carrying roller 331 for taking in. .

  As a result, the card MC can be taken inside. When the card MC is inserted all the way beyond the position of the shutter 38, the leading end of the card MC is gripped by the transport roller 331, and the operation of taking in the card MC is started (step ST40).

  Here, in the present example, after the card MC is started to be taken in, for example, while the rear end of the card MC is projecting from the card insertion slot 311, the magnetic field generator 50 generates a disturbing magnetic field, and then, The generation of the disturbing magnetic field is stopped (step ST41). The generation time of the interference magnetic field can be managed by the elapsed time from the time of detection by the pre-head 39 for card insertion detection, the card width sensor 371, and the like.

  Next, after taking in the card MC to the position of the magnetic head 34 for reading, the magnetic head 34 performs a read operation or a write operation of the card MC (step ST42).

As described above, 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 projects from the card insertion slot 311.
As a result, for example, as shown by an imaginary line in FIG. 14, even if the skimming magnetic head 61 is attached to the outer side position of the card insertion port 311, for example, the surface of the front panel 20 of the upper device, the disturbing magnetic field is generated. Therefore, the magnetic data of the inserted card MC cannot be completely read by the skimming magnetic head 61. Therefore, it is possible to prevent unauthorized reading of magnetic data by the skimming magnetic head 61.

  Next, the discharging operation will be described with reference to FIGS. 15 and 16. FIG. 15 is a flowchart for explaining the operation when the card is ejected. FIG. 16 is a diagram for explaining the operation when the card is ejected.

  In this case, when the ejection operation of the card MC is started by the transport rollers 331, 332, 333 (step ST51) and the leading end of the ejected card MC in the ejection direction is detected by the card width sensor 371 (step ST52), the magnetic field is generated. The generator 50 is driven to generate a disturbing magnetic field (step ST53). The generation of the disturbing magnetic field is performed by the same processing as that shown in FIGS.

  After that, when the rear end of the card MC ejected by the photo sensor 352 is detected (step ST54), the drive motor 36 is stopped (step ST55), and the card ejection operation is completed. After that, the control unit 40 stops the drive of the drive control circuit 52 of the magnetic field generation device 50 and stops the generation of the disturbing magnetic field (step ST56).

  At the time when the card discharging operation is completed, the rear end of the card MC is held by the transport roller 331. The user can pull out the card MC from the card insertion slot 311 by lightly pulling the card MC. If the user forgets to take out the card MC, the carrier roller can be driven to collect the card MC inside after a lapse of a predetermined time.

  As described above, in the card reader 10 of the present embodiment, even when the card is ejected, the disturbing magnetic field is temporarily generated with the tip of the ejection side protruding from the card insertion slot 311 to the outside. . Therefore, even if the skimming magnetic head 61 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 from being read.

  In this example, the magnetic field generator 50 is only driven once for a predetermined period at the time of card insertion and ejection, but it 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 this embodiment.
The present embodiment basically has an LC parallel resonance circuit formed by connecting a coil L that is an inductor and a capacitor C, and a strong magnetic field is generated by the LC parallel resonance circuit for a predetermined period due to the retention characteristic of resonance energy. It occurs continuously.
Then, in the present embodiment, the charging timing of the magnetic field generation unit 51 is controlled according to the direction of the current flowing through the coil L51 obtained by the monitoring of the current direction monitoring circuit 53.
Further, when the magnetic field generation device 50 repeatedly performs charging and resonance continuously, the magnetic field generator 50 does not perform charging at the timing when the current of the coil L51 flows in the opposite direction during resonance (the capacitor C51 is discharging). Therefore, there is no fear that the counter electromotive force is generated and damages the driving power supply unit 525 (power supply circuit), and safe and energy efficiency, for example, disturbing magnetic field control with good charge efficiency to the capacitor C51 becomes possible.

  In the magnetic field generation device 50, the determination unit 523 includes a time determination unit 5231 that determines whether or not a preset resonance time Tr has elapsed after stopping charging, and the operation instruction unit 5233 determines the resonance time Tr. After a lapse of time, it is confirmed that the current flowing through the coil L51 has changed to the first direction current IL1 in the positive direction, and drive control is performed so as to charge the magnetic field generation unit 51. With this, the resonance time Tr set in advance is determined, and it is confirmed that the current has changed to the first direction after an appropriate time has elapsed. Therefore, the resonance portion 511 (magnetic field generation portion 51) is further determined. It is possible to realize with high accuracy the timing of storing a charge by passing a DC current through the capacitor C51.

  Further, in the magnetic field generator 50, the time determination unit 5231 of the determination unit 523 determines whether or not the preset monitoring time Tm has elapsed after the resonance time Tr has elapsed, and the operation instructing unit 5233 determines the monitoring time Tm. When the time has passed and the current flowing through the coil L51 does not turn into the positive first direction current IL1, the drive control is performed so as to charge the magnetic field generation unit 51. As a result, the magnetic field generator 50 controls the operation instructing unit 5233 to charge the magnetic field generating unit 51 when the current flowing through the coil C51 does not turn into the first direction current IL1 after the monitoring time Tm elapses. Therefore, it becomes possible to continuously perform charging and resonance for a desired period.

  Further, the time determination unit 5231 of the magnetic field generation device 50 determines whether or not the preset charging time Tc has elapsed, and the operation instructing unit 5233 determines whether or not the charging direction Tc has exceeded the monitoring result of the current direction monitoring circuit 53. When the current flowing through the coil L51 turns into the first direction current IL1, the resonance is started after the charging time Tc ends. Accordingly, when the operation instructing unit 5233 recognizes that the preset charging time Tc has elapsed, the operation instructing unit 5233 drives and controls the magnetic field generating unit 51 to the resonance state, so that the resonance can be started at an appropriate timing.

  Further, the operation instruction unit 5233 of the determination unit 523 terminates the drive control of the magnetic field generation unit as an abnormality when the current flowing through the coil L51 does not turn into the first direction current IL1 within the charge time Tc. It is possible to detect damage to the resonance circuit element (the coil L51, the capacitor C51, etc.) that configures the resonance unit 511 and the malfunction due to the disconnection of the coil L51, and it is possible to improve the reliability of the magnetic field generation device 50. Becomes

Next, in the present embodiment, in the magnetic field generation device 50, by monitoring the direction of the alternating current flowing in the coil L51 and / or monitoring the number of current direction reversals, the direct current is supplied to the capacitor C51 of the parallel resonant circuit. It is possible to optimize the timing of flowing and storing electric charge.
Therefore, it is possible to control the disturbing magnetic field with high accuracy and efficiency, and it is possible to reliably prevent illegal acquisition of magnetic data by using the skimming magnetic head.
Further, in the magnetic field generation device 50, by monitoring the number of times the current flowing through the coil L51 is reversed in the current direction, it is possible to detect damage to the resonance circuit element or malfunction due to disconnection of the coil. The reliability can be improved.
Further, since the timing of charging is controlled when the number of times of current direction reversal reaches the specified number of times, the timing of accumulating charges with higher accuracy can be optimized.

  In the present embodiment, the card reader 10 for processing the magnetic data recorded on the card MC has the magnetic field generation device 50 for generating a magnetic field that interferes with the reading of the magnetic data of the card MC. Since the current direction monitoring circuit 53 is composed of a comparator (comparator) circuit element, it is possible to suppress an increase in the size of the structure and to optimize the timing of storing a charge by flowing a DC current through the capacitor C51 of the resonance circuit. Therefore, it is possible to control the disturbing magnetic field with high accuracy and efficiency. Further, in the card reader 10, it is possible to continuously and efficiently generate an interfering magnetic field with an appropriate time and intensity, and it is possible to reliably prevent illegal acquisition of magnetic data with high accuracy. .

  Therefore, according to the present embodiment, in order to read the magnetic data of the card, the fraudulent person can use the so-called skimming including the magnetic head for skimming and the magnetic reading circuit in the card insertion opening 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, not only increase the output of the disturbing magnetic field but also control the disturbing magnetic field with good energy efficiency, and for skimming. Unauthorized acquisition of magnetic data using the magnetic head can be reliably prevented with high accuracy.

[Other Embodiments]
Although the embodiment of the present invention has been specifically described above, it is needless to say that the present invention is not limited to the above embodiment and can be variously modified without departing from the scope of the invention.

For example, in the above-described embodiment, as shown in FIG. 3, an LC parallel resonance circuit in which a coil (inductor) L51 and a capacitor (capacitor) C51 are connected in parallel is used, but the present invention is not limited to this, and for example, It may be an LC series resonance circuit in which a coil (inductor) L51 and a capacitor (capacitor) C51 are connected in series.
For example, in the above-described embodiment, the parallel resonance circuit of the magnetic field generation unit 51 is formed by winding the coil L51 around the iron core FC as shown in FIG. 3, but as shown in FIG. It is also possible to form by L1.

When the magnetic field generator 50 is applied to the card reader 10, the magnetic field generation is temporarily stopped and the resonance energy of the resonance unit 511 of the drive control circuit 52 is released so that the residual disturbing magnetic field does not affect the magnetic detection. It is also possible to adopt a configuration for (discharging).
With this configuration, for example, in the magnetic field generator 50C, a transistor serving as a first switching element for discharging is connected to the first node ND52 of the resonance unit 511 to secure a resonance energy emission path (discharge path, escape path). can do.

Further, in the magnetic field generation device 50C, the supply line of the drive voltage VCC of the drive power supply unit 525 to the resonance unit 511 supplies the drive voltage VCC to the first node ND52 of the resonance unit 511 when the disturbing magnetic field generation operation is stopped. A transistor as a second switching element to be stopped is connected.
In this case, when the magnetic field generating operation is stopped, preferably, the second switching element is turned off to disconnect the first node ND52 from the supply source of the drive voltage VCC, and then the first switching element is turned on to resonate. Release energy. As a result, resonance energy can be efficiently discharged (discharged).

On the other hand, at the start of magnetic field generation, the first switching element is turned off to close the discharge path, and then the second switching element is turned on to connect to the supply source of the drive voltage VCC. As a result, the magnetic field generation can be efficiently started or restarted.
By adopting such a configuration, it is possible to prevent erroneous detection of the magnetic field by the pre-head 39, and it is possible to perform opening / closing control of the shutter with good responsiveness, and even if the card is inserted quickly, It is possible to prevent the occurrence of an event such as a collision (collision) with the shutter.

  10 ... Card reader (magnetic recording medium processing device), 20 ... Front panel, 21 ... Opening, 30 ... Card processing unit, 34 ... Magnetic head, 311 ... Card insertion port, 37 ... Card insertion detection mechanism, 371 ... Card detection sensor, 38 ... Shutter, 39 ... Pre-head, 40 ... Control unit, 50, 50C ... Magnetic field generator, 51 ... Magnetic field generation unit, 511 ... Resonance unit, 52, 52A, 52B ... Drive control circuit, 521, 521B ... Storage unit, 522 ... Clock unit, 523, 523B ... Judgment unit, 5231. ..Time determination section, 5232, 5232B ... Current direction determination section, 5233, 5233B ... Operation instruction section, 524 ... Driver, 525 ... Driving power supply section, 526 ... Reference potential section, 527 ···Both Drive section, 53, 53C ... Current direction monitoring circuit, 531 ... Comparator, R51 to R54 ... Resistor element, L51 ... Inductor (coil), C51 ... Capacitor, DSW51 ... Drive switching Element, MC ... Card.

Claims (12)

A card insertion slot where a card is inserted,
A card insertion detection mechanism that detects that the card is inserted from the card insertion opening,
A pre-head that detects the magnetic stripe of the card based on magnetism ,
A magnetic field generator for generating a disturbing magnetic field for preventing illegal reading of magnetic data recorded on the magnetic stripe;
When the card insertion detection mechanism detects the card insertion, the generation of the disturbing magnetic field is stopped, and when the pre-head detects the magnetic stripe in the stopped state, the generating of the disturbing magnetic field is started. A control unit for controlling
Equipped with
The control unit controls the magnetic field generation device to generate a disturbing magnetic field for a predetermined time from a time point when the pre-head detects the magnetic stripe or a time point when the card insertion detection mechanism detects the card. the magnetic recording medium processing device for. The magnetic recording according to claim 1 , wherein the predetermined time is either a time until the pre-head becomes a state in which the magnetic stripe is not detected or a state in which the card insertion detection mechanism does not detect the card. Media processing device. A magnetic head for reading and / or writing the magnetic data with respect to the magnetic stripe;
Wherein, after the elapse of the predetermined time, the magnetic recording medium processing apparatus according to claim 1 or 2, wherein controlling said magnetic head so as to perform read and / or write of the magnetic data. A card insertion slot where a card is inserted,
A card insertion detection mechanism that detects that the card is inserted from the card insertion opening,
A pre-head that detects the magnetic stripe of the card based on magnetism,
A magnetic field generator for generating a disturbing magnetic field for preventing illegal reading of magnetic data recorded on the magnetic stripe;
When the card insertion detection mechanism detects the insertion of the card, the generation of the disturbing magnetic field is stopped, and when the pre-head detects the magnetic stripe in the stopped state, the generation of the disturbing magnetic field is started. A control unit for controlling
A magnetic head for reading and / or writing the magnetic data with respect to the magnetic stripe;
A card transport path through which the card is transported from the card insertion port toward the magnetic head,
A shutter that opens and closes the card transport path,
A card transport mechanism for transporting the card,
The control unit opens the shutter after starting the generation of the disturbing magnetic field, activates the card transport mechanism, and controls the magnetic field generation device to generate the disturbing magnetic field until the loading of the card is completed. Control
Magnetic recording medium processing apparatus. Wherein the control unit is configured to convey the card to the magnetic head along the card transport path by the card transport mechanism according to claim 4 for controlling the whole apparatus to perform reading and / or writing of the magnetic data Magnetic recording medium processing device. A card insertion slot where a card is inserted,
A card insertion detection mechanism that detects that the card is inserted from the card insertion opening,
A pre-head that detects the magnetic stripe of the card based on magnetism,
A magnetic field generator for generating a disturbing magnetic field for preventing illegal reading of magnetic data recorded on the magnetic stripe;
When the card insertion detection mechanism detects the card insertion, the generation of the disturbing magnetic field is stopped, and when the pre-head detects the magnetic stripe in the stopped state, the generating of the disturbing magnetic field is started. A control unit for controlling
A card transport mechanism for transporting the card,
When the card transport mechanism transports the card toward the card insertion slot,
The control unit drives the magnetic field generator when the card insertion detection mechanism detects the leading end of the card in the ejection direction, and generates the magnetic field when the card insertion detection mechanism detects the trailing end of the card in the ejection direction. Stop the device
Magnetic recording medium processing apparatus. A card insertion slot where a card is inserted,
A card insertion detection mechanism that detects that the card is inserted from the card insertion opening,
A pre-head that detects the magnetic stripe of the card based on magnetism ,
A control method for a magnetic recording medium processing device, comprising: a magnetic field generating device that generates a disturbing magnetic field for preventing magnetic data recorded on the magnetic stripe from being illegally read.
When the card insertion detection mechanism detects the card insertion, the generation of the disturbing magnetic field is stopped, and when the pre-head detects the magnetic stripe in the stopped state, the generation of the disturbing magnetic field is started .
The magnetic field generator is controlled so as to generate an interfering magnetic field for a predetermined time from either the time when the pre-head detects the magnetic stripe or the time when the card insertion detection mechanism detects the card. A control method of a recording medium processing device. The magnetic recording according to claim 7 , wherein the predetermined time is either a time until the pre-head does not detect the magnetic stripe or a time when the card insertion detection mechanism does not detect the card. A method for controlling a medium processing device. After lapse of the predetermined time, so as to perform read and / or write of the magnetic data, according to claim 7 or 8, wherein controlling the magnetic head for reading and / or writing of the magnetic data to the magnetic stripe Control method of magnetic recording medium processing device. A card insertion slot where a card is inserted,
A card insertion detection mechanism that detects that the card is inserted from the card insertion opening,
A pre-head that detects the magnetic stripe of the card based on magnetism,
A magnetic field generator for generating a disturbing magnetic field for preventing illegal reading of magnetic data recorded on the magnetic stripe;
A method of controlling a magnetic recording medium processing apparatus, comprising: a magnetic head that reads and / or writes the magnetic data from the magnetic stripe,
When the card insertion detection mechanism detects the card insertion, the generation of the disturbing magnetic field is stopped, and when the pre-head detects the magnetic stripe in the stopped state, the generation of the disturbing magnetic field is started.
After the generation of the disturbing magnetic field is started, a shutter that opens and closes a card transport path through which the card is transported from the card insertion port toward the magnetic head is opened, and the card transport mechanism that transports the card is activated. The magnetic field generator is controlled to generate the disturbing magnetic field until the card is completely loaded.
The method of magnetic recording medium processing device. 11. The magnetic recording medium processing according to claim 10 , wherein the card transport mechanism transports the card to the magnetic head along the card transport path and controls the entire apparatus to read and / or write the magnetic data. Device control method. A card insertion slot where a card is inserted,
A card insertion detection mechanism that detects that the card is inserted from the card insertion opening,
A pre-head that detects the magnetic stripe of the card based on magnetism,
A magnetic field generator for generating a disturbing magnetic field for preventing illegal reading of magnetic data recorded on the magnetic stripe;
A method of controlling a magnetic recording medium processing apparatus, comprising: a card transport mechanism for transporting the card,
When the card insertion detection mechanism detects the card insertion, the generation of the disturbing magnetic field is stopped, and when the pre-head detects the magnetic stripe in the stopped state, the generation of the disturbing magnetic field is started.
When the card transport mechanism transports the card toward the card insertion slot,
When the card insertion detection mechanism detects the leading end of the card in the ejection direction, the magnetic field generator is driven, and when the card insertion detection mechanism detects the trailing end of the card in the ejection direction, the magnetic field generator is stopped.
The method of magnetic recording medium processing device.

Images