JP5073975B2 - IC card destruction device - Google Patents

Description

  The present invention relates to an IC card destruction device that reliably destroys information stored in a card when discarding an IC card that stores a record of money transactions or personal information.

  In recent years, a full-scale spread of non-contact IC cards has come. The non-contact IC card incorporates a coiled antenna in addition to the IC module in the card, and supplies power and exchanges information with radio waves. The card surface is usually covered with resin and no contact terminals are provided. Since there is no electrical contact, there is an advantage that the durability is excellent and the maintenance cost of the reading apparatus can be reduced. Such non-contact IC cards are used for employee cards, transportation cards, electronic money cards, and the like.

  On the other hand, leakage of personal information often becomes a social problem in recent years. Regarding non-contact IC cards, when discarding cards that are no longer used, it is necessary to take measures to prevent personal information from leaking to third parties.

Japanese Patent Laying-Open No. 2003-132307 (Patent Document 1) discloses a non-contact IC card destruction device that breaks a non-contact IC card so that it cannot be used. This non-contact IC card destruction apparatus disables the card by cutting a part of a loop antenna or a circuit built in the non-contact IC card.
JP 2003-132307 A JP 2003-157411 A JP 2004-141854 A

  In the above IC card destruction method, the IC chip is not destroyed and remains in an almost perfect form even after the antenna is cut. Therefore, if a loop antenna is intentionally added to the IC chip or the circuit is repaired, communication can be performed again, and there is a problem that it is not possible to guarantee destruction of data recorded on the card.

  In contrast, Japanese Patent Laid-Open No. 2003-157411 (Patent Document 2) discloses a non-contact type IC card destruction apparatus that destroys an IC inside a card when the card is discarded. This destruction device includes a strong magnetic field generation unit that causes destruction of the IC of the card by an alternating magnetic field having the same cycle as the carrier frequency used for power transmission and information communication performed by the non-contact type IC card with the reader / writer.

  However, this non-contact type IC card destruction device, after radiating a strong magnetic field to the card, is unclear whether or not the card IC is actually destroyed and cannot be read out. There was room for improvement to prevent.

  The object of the present invention is to make it impossible to read information stored in a contactless IC card, prevent card reproduction, duplication, and falsification, and to maintain confidentiality without leaking information to a third party after the card is discarded. It is to provide an IC card destruction device that can discard a card with peace of mind.

  In summary, the present invention is an IC card destruction device for destroying an IC card containing a semiconductor device, and a radiation portion that radiates electromagnetic waves to the IC card, and a change in electrical characteristics of the semiconductor device when the electromagnetic waves are radiated. And a control device that determines success or failure of the destruction of the IC card according to the output of the detection unit.

  Preferably, the IC card further includes a power receiving unit that receives electromagnetic waves and supplies power to the semiconductor device. The radiating unit radiates electromagnetic waves that cause the power receiving unit to generate electric power that exceeds the rated input power of the IC card. A detection part detects the change of the high frequency impedance of an IC card as an electrical property.

  More preferably, the radiating portion includes a loop coil. The detection unit includes a current detection unit that detects a high-frequency current supplied to the loop coil. The control device determines whether or not there is a change in the high frequency impedance of the IC card based on the detected high frequency current.

  Preferably, the IC card destruction device further includes a card discharge unit that switches a discharge method between when the destruction is successful after insertion of the IC card and when the IC card is not destroyed according to the output of the control device. .

  More preferably, the card ejection part includes a claw part for positioning the IC card when the radiation part radiates electromagnetic waves to the IC card. The claw portion opens and ejects the IC card when the destruction of the IC card is successful, and holds the card without ejecting when the IC card is not destroyed.

  According to another aspect of the present invention, there is provided an IC card destroying device for destroying a card including a semiconductor device and a power receiving unit that receives electromagnetic waves and supplies power to the semiconductor device, wherein the power exceeds the rated input power of the IC card. A radiation unit that radiates electromagnetic waves of a plurality of frequencies that cause the power reception unit to generate, and a control device that instructs the radiation unit to switch frequencies.

  Preferably, the IC card destruction device further includes a card detection unit that detects that the IC card is set in the IC card destruction device. The control device controls the radiation unit to sequentially radiate electromagnetic waves having a plurality of frequencies in accordance with the output of the card detection unit.

  Preferably, the radiating unit includes an oscillator, an amplifier circuit that receives the output of the oscillator, a capacitor for adjusting the capacitance on the output side of the amplifier circuit, a switch that couples the capacitor to the output side of the amplifier circuit, And a loop coil through which a current flows according to the output. The control device switches between the coupled state and the uncoupled state of the switch.

  According to the present invention, an IC card whose IC chip has been destroyed becomes impossible to read data, confidentiality is ensured without leaking information to a third party, and the card can be destroyed with peace of mind. become able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

FIG. 1 is a circuit diagram showing a configuration of an IC card destruction apparatus 100 according to the present embodiment.
Referring to FIG. 1, an IC card destruction device 100 destroys an IC card 20 containing a semiconductor device (IC chip). When the electromagnetic wave is emitted to the IC card, the radiation unit 6 emits the electromagnetic wave. In addition, a detection unit 8 that detects a change in electrical characteristics of the semiconductor device and a control unit (Micro Processor Unit) 10 that determines whether the IC card 20 has been destroyed or not according to the output of the detection unit 8 are included. As will be described later, the control device 10 performs different processes depending on the success or failure of the destruction. The radiation unit 6 causes the IC of the card to be destroyed by an alternating magnetic field having the same cycle as the carrier frequency (for example, 13.56 MHz) used for power transmission and information communication performed by the IC card 20 with the reader / writer.

  The IC card destruction apparatus 100 further includes a power switch 2, a power supply apparatus 4, an operation display lamp 12, a power lamp 14, and a card discharge unit 15. The card discharge unit 15 includes a card insertion slot, which will be described later with reference to the drawings, a solenoid 16, and a claw portion that is moved by the solenoid 16. The power supply device 4 includes a protection device 5 that outputs power supply voltages VCC1 and VCC2 from a commercial power supply of AC 100V and prevents an overcurrent from flowing when an overload occurs.

FIG. 2 is a diagram showing the configuration of the IC card 20.
Referring to FIG. 2, an IC card 20 includes a semiconductor device 112, a coil 111 that is a power receiving unit that receives electromagnetic waves and supplies power to the semiconductor device, and a resin card that hermetically supports the coil 111 and the semiconductor device 112. Substrate 110.

  Referring again to FIG. 1, the radiating unit 6 radiates an electromagnetic wave that generates power exceeding the rated input power of the IC card 20 in the coil 111 that is the power receiving unit. The detection unit 8 detects a change in high-frequency impedance of the IC card 20 as an electrical characteristic.

  The radiating unit 6 includes a PLL synthesizer 22, switches 24 and 32, an amplifier circuit 26, a transformer 27, capacitors 28 and 30, and a loop coil 34.

  The detection unit 8 includes a current detection unit 42 that detects a high-frequency current supplied to the loop coil 34, a detection circuit 41 that detects the amplitude of the output of the current detection unit 42, and an analog signal output by the detection circuit 41 as a digital signal. A / D converter 40 for conversion.

  The detection unit 8 further digitally converts an analog signal output from the detection circuit 37, a voltage detection unit 38 that detects a high-frequency voltage supplied to the loop coil 34, a detection circuit 37 that detects the amplitude of the output of the voltage detection unit 38, and the like. And an A / D converter 36 for converting the signal. Digital signals output from the A / D converters 36 and 40 are given to the control device 10.

  The control device 10 determines whether or not the high frequency impedance of the IC card 20 has changed based on the high frequency current detected by the current detection unit 42, and determines whether or not the IC chip mounted on the IC card has been destroyed.

FIG. 3 is a perspective view for explaining an arrangement example of each element of the IC card destruction apparatus.
FIG. 3 shows a state where a part of the casing 52 is removed in order to explain the inside of the IC card destruction apparatus.

  A card insertion slot 50 is provided in the upper part of the housing 52, and the card is held just beside the loop coil 34 by the claw portion moved by the solenoid 16, and a strong magnetic field is radiated toward the card. A printed wiring board 54 on which the control device 10 is mounted and the power supply device 4 are disposed around the loop coil 34. A card receiving box 56 for receiving the destroyed IC card is provided at the bottom of the housing 52.

  The power supply device 4 may be divided into a device for generating the power supply voltage VCC1 and a device for generating the power supply voltage VCC2 in FIG.

  On the rear surface of the housing 52, a power switch 2 and a wiring outlet of a plug 58 for receiving power supply from a commercial power supply of AC 100V are provided.

FIG. 4 is a view of the card inserted from the side of the loop coil 34.
With reference to FIG. 1 and FIG. 4, the IC card destruction device 100, depending on the output of the control device 10, when the destruction is successful after inserting the IC card 20 and when the IC card is not destroyed, It further includes a card insertion slot 50, a solenoid 16, and a claw 62 that moves with the solenoid 16, constituting the card discharge unit 15 for switching the discharge method. The control device 10 switches the card discharge method as a different process depending on the success or failure of the card destruction.

  That is, when electromagnetic waves are emitted or the power is turned off, the claw portion 62 is in the position indicated by 62A. Then, when the destruction is successful, the control device 10 moves the claw 62 to the position indicated by 62B to discharge the card, and when it is not destroyed, the control device 10 stops the claw 62 at the position indicated by 62A and holds the card. Do not discharge.

  Further, as will be described later, the control device 10 changes the lighting method of the operation display lamp 12 as a different process depending on the success or failure of the card destruction. That is, the control device 10 blinks the operation display lamp 12 when the card is not destroyed.

  By these different processes, the user can know whether or not the destruction of the card has been completed normally.

FIG. 5 is a perspective view showing the shapes of the solenoid 16 and the claw portion 62.
With reference to FIGS. 4 and 5, the claw portion 62 positions the IC card 20 when the radiating portion 6 radiates electromagnetic waves to the IC card 20. When the destruction of the IC card 20 is successful, the claw portion 62 opens and ejects the IC card 20 as shown at the position 62B. When the IC card 20 is not destroyed, the claw part 62 shows as shown at the position 62A. The card 20 is held without being discharged. That is, by turning on / off the magnetic force of the solenoid, the iron piece inside is attracted or released to move the claw portion 62 in the direction indicated by the arrow A2. The released IC card 20 falls by its own weight in the direction indicated by the arrow A1.

FIG. 6 is a perspective view for explaining the shape of a sensor that detects insertion of a card.
4 and 6, the card detection sensor 18 provided with the slit is disposed above the claw portion 62 and on the side of the card 20. In a state where the card 20 is inserted and held by the claw portion 62, a part of the card 20 is inserted into the slit of the card detection sensor 18.

  The card detection sensor 18 includes a light emitting element such as a light emitting diode that emits light in the direction indicated by the arrow A3, and an optical sensor that receives the light. When the card 20 is inserted and held, the light is blocked and the optical sensor does not detect the light. Thereby, it can be detected that the card 20 is inserted. The insertion of the card may be detected using not only light but other proximity sensors.

  The operation of the IC card destruction apparatus 100 will be described with reference to FIGS. 1 and 3 again. The PLL synthesizer 22 can vary the frequency under the control of the control device 10 and generates a high frequency. This high frequency is amplified to an electric power sufficient to destroy the card by the amplifier circuit 26 via the switch 24. The output of the amplifier circuit 26 drives the primary side of the transformer 27. The output on the secondary side of the transformer 27 is applied to a series resonance circuit including the resonance capacitors 28 and 30 and the loop coil 34.

  Switch 32 is used to add a capacitor 30 to the resonant circuit to correct the resonant frequency. When the switch 32 is turned on, the capacitor 30 is not added to the resonance circuit, and when the switch 32 is turned off, the capacitor 30 is added to the resonance circuit.

  The insertion path is configured so that the IC card 20 inserted from the card insertion slot 50 is electromagnetically coupled to the loop coil 34 installed on the side of the card. Further, it is detected that the IC card 20 is inserted by the card detection sensor 18 provided in the card path.

  The control device 10 starts applying high frequency to the loop coil 34 by turning on the switch 24 and irradiates the card 20 with electromagnetic waves. At the same time, the control device 10 supplies the high-frequency voltage and current supplied to the loop coil 34 to the voltage detection unit 38 (voltage transformer), the detection circuit 37 and the A / D converter 36, the current detection unit 42 (current transformer), and the detection circuit. 41 and the A / D converter 40, and the load impedance of the loop coil 34 including the card 20 is monitored.

  In another aspect, this embodiment is an IC card destruction apparatus 100 that destroys a card containing a semiconductor device and a power receiving unit that receives electromagnetic waves and supplies power to the semiconductor device, and is a rated input power of the IC card. The radiation part 6 which radiates | emits the electromagnetic wave of the several frequency which generates the electric power which exceeds this in a power receiving part, and the control apparatus 10 which instruct | indicates switching of a frequency with respect to the radiation part 6 are also included.

  Preferably, the IC card destruction apparatus 100 further includes a card detection sensor 18 that detects that the IC card 20 is set in the IC card destruction apparatus. The control device 10 controls the radiation unit 6 so as to sequentially radiate electromagnetic waves having a plurality of frequencies according to the output of the card detection sensor 18.

  Preferably, the radiating unit 6 includes a PLL synthesizer 22 that is an oscillator, an amplifier circuit 26 that receives the output of the oscillator, a capacitor 30 for adjusting the capacitance on the output side of the amplifier circuit 26, and the capacitor 30 as an amplifier circuit. 26 includes a switch 32 coupled to the output side of 26 and a loop coil 34 through which a current flows in accordance with the output of the amplifier circuit 26. The control device 10 switches between a coupled state and a non-coupled state of the switch 32. When the switch 32 is opened, the capacitance of the capacitor 30 is coupled to the amplifier circuit 26, and when the switch 32 is closed, the capacitor 30 is coupled to the amplifier circuit 26 in a non-coupled state.

  That is, considering the resonance frequency shift due to the difference in the load capacity of the IC card 20, the high frequency is effectively applied by switching the capacitance of the series resonance capacitor with the switch 32 to apply impedance multiple times while matching the impedance. It is configured so that the card can be efficiently destroyed.

  When the impedance of the IC card 20 becomes lower than the initial value after the electromagnetic wave is radiated, the control device 10 determines that the semiconductor device 112 in the card 20 of FIG. Stop applying and eject the card.

  On the other hand, if there is no significant change in the impedance value, the control device 10 determines that the inserted object is not a destroyed non-contact IC card, stops the application of electromagnetic waves, and removes the card. Hold without discharging.

  The electromagnetic wave irradiation may be continuous or intermittently repeated in a pulse shape.

  FIG. 7 is a flowchart showing a control structure of a program executed by the control device 10.

  Referring to FIGS. 1 and 7, when the process is started, the remaining cards are discharged in steps S1 and S2 in response to the power switch being turned on. When the solenoid 16 is energized, the claw portion 62 (stopper) is temporarily held at the position indicated by 62B in FIG. 4, and the card falls by its own weight. When the card is completely discharged, the energization of the solenoid 16 is released again, and the claw portion 62 returns to the position indicated by 62A by the elastic force of a spring or the like. And the control apparatus 10 waits for insertion of a card | curd.

  As shown in FIG. 4, the IC card inserted from the card insertion slot 50 is prevented from dropping by the claw portion 62 and is held at a position where it is electromagnetically coupled with the loop coil 34 close to the side surface of the card.

  A card detection sensor 18 (interrupter) provided with a slit is provided in a path through which the card passes. The control device 10 receives the output of the card detection sensor 18 and detects that a card to be destroyed is inserted.

  While the card is not inserted, the card detection wait state is entered (step S3). When the card is inserted, the process proceeds to step S4, and the control device 10 turns on the switch 24, transmits the source oscillation signal of the PLL synthesizer 22 to the amplifier circuit 26, and starts applying a high frequency to the loop coil. . The loop coil 34 irradiates the IC card 20 with an electromagnetic wave stronger than normal data writing. Irradiation with electromagnetic waves may be continuous or intermittently repeated in pulses. At the same time, the control device 10 lights the operation display lamp 12 to display that the destructive operation is being performed.

  In step S4, simultaneously with the application of the high frequency, the control device 10 measures the high frequency voltage and current supplied to the loop coil and monitors the load impedance of the loop coil including the card. That is, the value obtained by dividing the high-frequency voltage by the high-frequency current is defined as the load impedance.

  In step S5, the control device 10 determines whether or not the electromagnetic wave irradiation started in step S4 has been performed for a predetermined time, and the electromagnetic wave irradiation is continued until the predetermined time is reached.

  If the predetermined time has elapsed in step S5, the process proceeds to step S6. In step S6, the control device 10 considers the shift of the resonance frequency caused by the difference in the load capacity of the card, and switches the value of the resonance capacitor that constitutes the loop coil and the series resonance circuit to shift the frequency to continue the electromagnetic wave irradiation. To do. Depending on the load capacity of the card, reflection is reduced and the card is effectively irradiated with electromagnetic waves. In this way, by applying a plurality of frequencies corresponding to the variation in the resonance frequency, the card can be destroyed in a short time with less power.

  In step S7, the control device 10 determines whether or not the irradiation of the electromagnetic wave whose resonance frequency is shifted in step S6 has been performed for a predetermined time, and the irradiation of the electromagnetic wave is continued until the predetermined time is reached. Also at this time, the irradiation of electromagnetic waves may be continuous or intermittently repeated in a pulse shape.

  If the predetermined time has elapsed in step S7, the process proceeds to step S8. In step S <b> 8, the control device 10 releases the switch 24 and stops the irradiation of the electromagnetic wave from the loop coil 34. At the same time, the control device 10 turns off the operation display lamp and notifies the stop of the electromagnetic wave irradiation.

  Subsequently, in step S9, the control device 10 determines whether or not a change exceeding a threshold value has occurred in the load impedance monitored while irradiating the electromagnetic wave. If there is a change in the load impedance, it is determined that the card has been destroyed, the process proceeds to step S10, and the control device 10 drives the solenoid 16 to release the stopper and eject the card 20.

  On the other hand, when no change in impedance is detected in step S9, it is considered that the card is not a destruction target (foreign matter) or an IC card that could not be destroyed. The operation display lamp 12 is blinked while the card is held without energizing the card to notify that the destruction of the card has not been completed, and the process ends.

  In this case, the user once removes the card that has been destroyed so far from the card receiving box 56, and then once turns off the power switch 2 and turns it on again (after about 10 seconds). The process returns to step S2 and the card is discharged. The user can distinguish a card that has not been destroyed in this way from a card that has been destroyed.

  Next, the method for determining the impedance change in step S9 in FIG. 7 will be described in detail.

  According to an experiment conducted by the applicant, when an excessive electromagnetic wave is irradiated to a normal card, the IC chip is instantaneously destroyed and short-circuited by an excessive voltage generated inside the IC card, and the impedance of the load is lowered and the high-frequency current is increased. Therefore, it is possible to determine whether or not the card is destroyed.

FIG. 8 is a diagram illustrating changes in the detection current and the detection voltage when the card is not destroyed.
FIG. 9 is a diagram illustrating changes in the detection current and the detection voltage when the card is destroyed.

  8 and 9, the vertical axis indicates the sample value when the voltage / current value is taken in by the A / D converter, and the horizontal axis indicates the time. As shown in FIG. 8, in an undestructed state, the current value is less than 20 and the voltage value is stable between 100 and 120. On the other hand, in the state of FIG. 9, the current value exceeds 250 at the peak time, and the voltage value is about 200th. In FIG. 9, the current value and the voltage value decrease with time due to the function of the protective device 5 (or the device that stabilizes the voltage) that protects against the overcurrent built in the power supply device 4. . As time passes, the voltage settles to the same value (between 100 and 120) as shown in FIG.

  There are several possible methods for detecting card destruction based on impedance change, but any method may be adopted. For example, the impedance may be calculated by actually dividing the voltage value by the current value and compared with the threshold value. Further, when the processing capacity of the control device 10 is low, it may be determined only by the current value. First, irradiate an electromagnetic wave that supplies power within the rating of the IC card, obtain the impedance at that time, store the value in the control device, and then obtain the impedance after irradiating the electromagnetic wave exceeding the rating. When a change of a predetermined amount or more is recognized as compared with the stored value, it may be determined that the card is destroyed.

  In the present embodiment, a loop coil is installed vertically and a card is inserted from above the coil so that it is dropped by its own weight when ejected. The card may be moved and held using a driving conveyance means (rubber roller, belt, etc.), and the loop coil may be installed horizontally or diagonally. Or you may put in and out a card using a tray. Further, instead of holding a card that could not be destroyed and not discharging it, it may be discharged from another outlet.

  Preferably, the IC card on which the IC chip has been destroyed may be further cut with a cutter to destroy information on characters, images, barcodes, magnetic stripes, embosses, etc. printed on the card surface. .

  Furthermore, the present invention can be suitably applied to an apparatus for destroying a non-contact type IC card, but can also be applied to a card combined with a contact reading medium such as magnetism.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is the circuit diagram which showed the structure of the IC card destruction apparatus 100 which concerns on this Embodiment. 2 is a diagram showing a configuration of an IC card 20. FIG. It is a perspective view for demonstrating the example of arrangement | positioning of each element of an IC card destruction apparatus. It is the figure which looked at the card | curd of the state inserted from the side of the loop coil 34. FIG. FIG. 6 is a perspective view showing shapes of a solenoid 16 and a claw portion 62. It is a perspective view for demonstrating the shape of the sensor which detects insertion of a card | curd. It is the flowchart which showed the control structure of the program which the control apparatus 10 performs. It is a figure which shows the change of the detection current and detection voltage when a card | curd is not destroyed. It is a figure which shows the change of the detection current and detection voltage when a card | curd is destroyed.

Explanation of symbols

  2 Power switch, 4 Power supply device, 5 Protection device, 6 Radiation unit, 8 Detection unit, 10 Control device, 12 Operation indicator lamp, 14 Power supply lamp, 15 Card ejection unit, 16 Solenoid, 18 Card detection sensor, 20 IC card, 22 PLL synthesizer, 24, 32 switch, 26 amplifier circuit, 27 transformer, 28, 30 capacitor, 34 loop coil, 36, 40 A / D converter, 37, 41 detector circuit, 38 voltage detector, 42 current detector, 50 card insertion slot, 52 housing, 54 printed wiring board, 56 card receiving box, 58 plug, 62 claw part, 100 card destruction device, 110 card base material, 111 coil, 112 chip, 112 semiconductor device.

Claims (8)

An IC card destruction device for destroying an IC card containing a semiconductor device,
Radiation means for radiating electromagnetic waves to the IC card;
Detecting means for detecting a change in electrical characteristics due to burning of the semiconductor device when emitting the electromagnetic wave;
An IC card destruction apparatus comprising: control means for determining whether the semiconductor device is burned or not according to the output of the detection means. The IC card further includes power receiving means for receiving electromagnetic waves and supplying power to the semiconductor device,
The radiating means radiates electromagnetic waves that cause the power receiving means to generate power exceeding the rated input power of the IC card,
The IC card destruction apparatus according to claim 1, wherein the detection unit detects a change in high-frequency impedance of a circuit configured by the power reception unit and the semiconductor device as the electrical characteristic. The radiating means is
Including a loop coil,
The detection means includes
Current detection means for detecting a high-frequency current supplied to the loop coil,
The IC card destruction apparatus according to claim 2, wherein the control means determines whether or not there is a change in the high-frequency impedance of a circuit configured by the power receiving means and the semiconductor device based on the detected high-frequency current. In response to the output of said control means, in the case where the the case where the semiconductor device is burned after inserting the IC card semiconductor device does not burn, further comprising a card discharge means for switching the discharging method, according to claim 1 IC card destruction apparatus as described in. The card ejecting means includes a claw portion for positioning the IC card when the radiation means radiates electromagnetic waves to the IC card, and the claw portion opens the IC card when the semiconductor device is burned out. The IC card destruction apparatus according to claim 4, wherein the card is held without being discharged when the semiconductor device is not burned out . The IC card further includes power receiving means for receiving electromagnetic waves and supplying power to the semiconductor device ,
Radiation means for radiating electromagnetic waves of a plurality of frequencies that cause the power receiving means to generate power exceeding the rated input power of the IC card;
The IC card destruction apparatus according to claim 1, wherein the control means instructs the radiation means to switch a frequency. Card detecting means for detecting that the IC card is set in the IC card destruction device;
The IC card destruction apparatus according to claim 6, wherein the control unit controls the radiating unit to sequentially radiate the electromagnetic waves having the plurality of frequencies in accordance with an output of the card detecting unit. The radiating means is
An oscillator,
An amplifier circuit receiving the output of the oscillator;
A capacitor for adjusting the capacitance on the output side of the amplifier circuit;
A switch for coupling the capacitor to the output side of the amplifier circuit;
A loop coil through which a current flows according to the output of the amplifier circuit,
The IC card destruction apparatus according to claim 6 or 7, wherein the control means switches between a coupled state and a non-coupled state of the switch.

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