JP2000172792A - Non-contact type ic card reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently supply power to an IC card and to make it operable. SOLUTION: In a reader/writer 1 which is provided with a resonance circuit 14 and feeds power supply to an IC card 2 while the circuit 14 is subjected to electromagnetic coupling with the resonance circuit 22 of the card 2, the circuit 14 consists of capacitors C1 and C2 and an antenna L, the resonance frequency of the circuit 14 is successively adjusted by successively and automatically changing the capacity value of the variable capacitor C2, a response signal from the IC card is also detected whenever the resonance frequency is adjusted, a response signal where peak width is the largest and also the number of peaks is the most is selected as an optimum response signal among detected response signals, and a resonance frequency corresponding to the optimum response signal is set as the optimum resonance frequency for the circuit 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact type IC card reader for recording and reproducing data on a non-contact type IC card.

[0002]

2. Description of the Related Art A non-contact type IC card reader of this type is provided with a resonance circuit including an antenna having an inductive component and a capacitor. The antenna of the resonance circuit is electromagnetically coupled to supply power from the IC card reader device to the IC card. Here, power is efficiently supplied from the IC card reader device to the IC card by bringing the resonance frequencies of the respective resonance circuits of the IC card reader device and the IC card close to each other.

[0003]

The conventional IC
In the card reader device, a resonance frequency that matches a resonance frequency of a resonance circuit of the card when a distance from one IC card is set to, for example, 5 mm is set as its own resonance frequency. However, although each IC card is designed to have the same resonance frequency, the resonance frequency varies among the IC cards, and the distance between the IC card reader device and the IC card is also a fixed distance (5 mm).
However, power is not efficiently supplied to the IC card, and in some cases, operable power cannot be supplied to the IC card.

Further, such an IC card reader device can process even if a plurality of IC cards are placed at the same time, but when such a plurality of IC cards are placed, a plurality of IC cards are placed. As a result, the resonance frequency of the IC card changes, and in such a case, the IC card may not operate. Accordingly, it is an object of the present invention to efficiently supply power to an IC card and make the IC card operable.

[0005]

In order to solve such a problem, the present invention comprises a first resonance circuit,
The first resonance circuit is a non-contact type IC card reader that electromagnetically couples with the second resonance circuit of the IC card and supplies power to the IC card via the second resonance circuit. Variable means for varying the frequency, adjusting means for controlling the variable means to adjust the resonance frequency of the first resonance circuit, and a response signal indicating that power has been supplied to the IC card after adjusting the resonance frequency of the adjusting means. Detecting means for detecting the presence / absence of the first resonance circuit, and controlling the adjusting means to sequentially adjust the resonance frequency of the first resonance circuit. And control means for selecting an optimum response signal from the above and setting a resonance frequency according to the selected response signal as a resonance frequency of the first resonance circuit. The first resonance circuit includes an antenna having an inductive component and a capacitive element provided as the variable unit, and the adjustment unit changes the capacitance value of the capacitive element to change the resonance frequency of the first resonance circuit. It is to adjust. When the second resonance circuit resonates on the basis of the resonance frequency of the first resonance circuit adjusted by the adjustment means, the IC card is supplied with power and has a response comprising a plurality of pulses having predetermined peak voltages and peak widths. The signal is transmitted, and the control means selects a response signal whose peak voltage and peak width conform to the standard as an optimal response signal. Further, when the second resonance circuit resonates based on the resonance frequency of the first resonance circuit adjusted by the adjustment means, power is supplied to the IC card, and the IC card responds after a lapse of a fixed time after the supply of the power. A signal is transmitted, and the control means determines that power is not supplied to the IC card if the detection means cannot detect a response signal for a time longer than the predetermined time after the resonance frequency is adjusted by the adjustment means.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a non-contact type IC card reader according to the present invention. This non-contact type IC card reader device (hereinafter, reader / writer 1)
The IC card 2 is electromagnetically coupled with the non-contact type IC card 2 to supply electric power to the IC card 2, and records and reproduces data with respect to the activated and activated IC card 2.

[0007] The reader / writer 1 includes a CPU 11 and a CPU.
And an ASK 100 for modulating the encoded data from the encoding circuit 12, which is called a modified mirror encoding circuit for encoding the data given from the encoder 11.
A modulation circuit 13 called a modulation circuit, a resonance circuit 14 in which an antenna L composed of an inductive component and capacitors C1 and C2 are connected in parallel, and an ASK demodulation circuit for demodulating data from the IC card 2 via the resonance circuit 14 are called. A demodulation circuit 15; a decoding circuit 16 called a Manchester code decoding circuit for decoding demodulated data from the demodulation circuit 15;
The power supply unit 17 supplies power to the above units. The IC card 2 includes a control unit 21 such as a CPU.
And a resonance circuit 22 in which an antenna similar to the antenna L of the resonance circuit 14 and a capacitor are connected in parallel.

Incidentally, the resonance circuit 14 of the reader / writer 1
When the IC card 2 is placed at a predetermined place and an operation unit (not shown) is operated to start a predetermined service, power is supplied from the power supply unit 17 and the antenna L
It oscillates at a frequency (resonant frequency) determined by each value of the capacitors C1 and C2. In this case, the resonance circuit 22 of the IC card 2 oscillates (resonates) in synchronization with the resonance frequency of the resonance circuit 14 of the reader / writer 1, and a voltage based on this oscillation is taken out as a DC voltage by a rectifier circuit (not shown), and the control unit 21. Is supplied as operating power.

When the reader / writer 1 reads data from the IC card 2 at the start of the service, a read request signal is sent from the CPU 11 to the encoding circuit 12. The read request signal is encoded by the encoding circuit 12 and sent to the modulation circuit 13. The modulation circuit 13 modulates the encoded signal and sends it to the resonance circuit 14. The resonance circuit 14 sends the modulated signal to the IC card 2 side.
In the IC card 2, the read request signal is sent to a demodulation circuit (not shown) via the resonance circuit 22, demodulated by the demodulation circuit, decoded by a decoding circuit (not shown), and sent to the control unit 21. When detecting this, the control section 21 reads out data from an internal memory (not shown) and sends it to an encoding circuit (not shown) for encoding (Manchester encoding). The encoded data is modulated by a modulation circuit (not shown) and sent to the resonance circuit 22, where it is superimposed on the frequency signal of the circuit 22 and transmitted to the reader / writer 1 side. In the reader / writer 1, the data from the IC card 2 is received and demodulated by the demodulation circuit 15 via the resonance circuit 14, decoded by the decoding circuit 15, and transmitted to the CPU 11. Thereby, the CPU 11 can read the data of the IC card 2.

On the other hand, when the service is completed and the reader / writer 1 updates the data of the IC card 2, the CPU
From 11, update data is sent to the encoding circuit 12. The update data is encoded by the encoding circuit 12 and sent to the modulation circuit 13. The modulation circuit 13 modulates the encoded data and sends it to the resonance circuit 14. The resonance circuit 14 sends out the modulated data to the IC card 2 side. In the IC card 2, the update data is sent to the demodulation circuit via the resonance circuit 14, demodulated by the demodulation circuit, decoded by the decoding circuit, and sent to the control unit 21. The control unit 21 stores the decoded data in an internal memory (not shown).

FIG. 2A is a sequence diagram showing the operation of the main part of the present invention, in which the reader / writer 1 checks the operation state of the IC card 2. As described above, when the IC card 2 is placed at a predetermined place and the start of a predetermined service process using the IC card 2 is instructed, the resonance circuit 14 of the reader / writer 1 Before the start, power is supplied from the power supply unit 17 to oscillate at a resonance frequency determined by the values of the antenna L and the capacitors C1 and C2. That is, the CPU 1 of the reader / writer 1
1 is a setting a for supplying power from the power supply unit 17 to the resonance circuit 14 and changing the value of the variable capacitor C2 of the resonance circuit 14 so that the resonance circuit 14 oscillates at the resonance frequency A. Make a request (Step S
1). Then, the resonance circuit 14 oscillates at the resonance frequency A.
Then, when the resonance circuit 22 of the IC card 2 oscillates (resonates) by the oscillation of the resonance circuit 14 and power is supplied to the control unit 21, the control unit 21 determines a predetermined value from the start time based on the power supply. About 0.3 ms (32 × 128/1
After 3.56 MHz), a response signal is returned to the reader / writer 1 via the resonance circuit 22.

If the resonance frequency A of the resonance circuit 14 of the reader / writer 1 and the resonance frequency of the resonance circuit 22 of the IC card 2 are different from each other, the resonance circuit 22 of the IC card 2 does not oscillate sufficiently. No operable power is supplied to the unit 21. Therefore, the control unit 21 does not operate and the IC card
Does not return a response signal (step S2). The CPU 11 of the reader / writer 1 sets the capacitance value of the variable capacitor C2 of the resonance circuit 14 to a new capacitance value because the response signal is not returned from the IC card 2 even after the elapse of 0.3 ms + α time. The setting b is set so that the circuit 14 oscillates at the resonance frequency B, and a response request is made to the IC card 2 (step S3). Then, the resonance circuit 14 oscillates at the resonance frequency B, and a radio signal having this resonance frequency B is transmitted to the IC card 2 side.

In this case, the resonance circuit 14 of the reader / writer 1
Assuming that the respective resonance frequency bands of the resonance frequency B and the resonance frequency of the resonance circuit 22 of the IC card 2 substantially match, the resonance circuit 22 of the IC card 2 starts oscillating (resonating), and the oscillation causes the control unit 21 to operate. Power is supplied, and the control unit 21 is activated. The activated control unit 21 returns a response signal to the reader / writer 1 via the resonance circuit 22 at the time when 0.3 ms has elapsed from the activation time (step S4). The CPU 11 of the reader / writer 1 receives this response signal directly from the demodulation circuit 15 without passing through the decoding circuit 16 as the Manchester code shown in FIG. The number of peaks (pulses) and the peak width of the received Manchester code shown in FIG. 2B are stored in the built-in memory 11A, and the setting data b (for the variable capacitor C2 of the variable (The capacity setting value) (step S5). Thereafter, the CPU 11 stops the oscillation of the resonance circuit 14 by stopping the power supply from the power supply unit 17 to the resonance circuit 14, for example. In the example of FIG. 2A, the peak number 3 and the peak width 4 are associated with the setting data b.
(The unit of the peak width is, for example, μsec.)
1A.

In this manner, the number of peaks and the width of the Manchester code included in the response signal from the IC card 2 are input by sequentially changing the resonance frequency of the resonance circuit 14 and stored in the built-in memory 11A together with the setting data of the variable capacitor C2. I will do it. Finally, the CPU 11 sets the resonance circuit 1
4 is made to supply power from the power supply unit 17 and a setting n request is made to oscillate the resonance circuit 14 at the resonance frequency N (step S
6) The resonance circuit 14 is oscillated at the resonance frequency N. As a result, the resonance circuit 22 of the IC card 2 oscillates similarly, and power is supplied to the control unit 21 by this oscillation and the control unit 21 is started.
The activated control unit 21 starts the above-mentioned 0.3 ms from this activation time.
When the time has elapsed, a response signal is similarly returned to the reader / writer 1 (step S7).

When the CPU 11 of the reader / writer 1 receives this response signal as a Manchester code, the CPU 11 similarly stores the number of peaks and the peak width in the built-in memory 11A, and sets the number of peaks and the peak width in pair with the set data n to the capacitor C2 in which the resonance frequency N is set. It is stored (step S8). In the example of FIG. 2A, the peak number 4 and the peak width 8 are stored in the internal memory 11A in association with the setting data n. CPU1 of reader / writer 1
1 selects the setting data having the largest peak number and peak width from the peak number and peak width of the response signal stored in the built-in memory 11A in this way, and transfers the setting data to the variable capacitor C2 of the resonance circuit 14. Set as the capacitance value. As a result, in the subsequent service processing, electric power can be supplied from the reader / writer 1 to the IC card 2 with high efficiency. Therefore, the IC card 2 can be reliably operated to read data from the IC card 2 or transfer data to the IC card. Can be written.

FIG. 3 is a flowchart of the operation of the CPU 11 of the reader / writer 1 in which the operation shown in FIG. 2A for supplying power to the IC card 2 is summarized. When the IC card 2 is mounted on a predetermined mounting place and a start instruction operation of a predetermined service process using the IC card 2 is performed, the CPU 11 first starts resonance from the power supply unit 17 before starting the service process. Power is supplied to the circuit 14, and at the same time, the resonance frequency is set by changing the capacitance value of the variable capacitor C2 of the resonance circuit 14 (step S11). Then, the resonance circuit 14 starts oscillating at the set resonance frequency, and uses a radio signal of this frequency as a response request signal as an IC.
The data is transmitted to the card 2 (step S12).

At the same time, the CPU 11
B is set to the above-mentioned time of 0.3 ms + α and activated (step S13). Thereafter, the CPU 11 determines whether or not the response signal returned from the IC card 2 has been
The timeout of B is determined in steps S14 and S15, respectively. If a response signal is received before the timeout of the built-in timer 11B, the number of peaks, the width of each peak, and the voltage of the response signal are set to the set value of the resonance frequency (that is, variable). The built-in memory 11 together with the capacitance set value of the capacitor C2)
A is stored in A (step S16). If the built-in timer 11B times out before the response signal is received, the response signal absence data is stored in the built-in memory 11A together with the set value of the resonance frequency (step S16).

When data is stored in the internal memory 11A, C
The PU 11 temporarily stops the power supply to the resonance circuit 14, and determines whether or not the last resonance frequency has been set for the resonance circuit 14 in step S17. In this case, since the setting is the first time, the process proceeds to step S11. Returning, the power is supplied from the power supply unit 17 to the resonance circuit 14, and at the same time, the capacitance of the variable capacitor C 2 is changed to the next new capacitance value.
4 is set to a new resonance frequency. Then, the resonance circuit 14 starts oscillating at the newly set resonance frequency. The CPU 11 transmits a response request signal to the IC card 2 (Step S12). At the same time, the CPU 11 starts the built-in timer 11B.

Thereafter, the CPU 11 determines whether or not the response signal returned from the IC card 2 has been received and the timeout of the built-in timer 11B in steps S14 and S14, respectively.
Similarly, if the response signal is received before the built-in timer 11B times out, the number of peaks of the response signal,
The width and voltage of each peak are stored in the built-in memory 11A together with the set value of the resonance frequency (step S16). Also,
When the built-in timer 11B times out before receiving the response signal, the data without response signal is stored in the built-in memory 11A together with the set value of the resonance frequency (step S16).

As described above, the CPU 11 sequentially operates the resonance circuit 1
Oscillation is performed by changing the resonance frequency of 4 and the number of peaks, the peak width, and the peak voltage value of the response signal returned from the IC card 2 are stored in the built-in memory 11A together with the set value of the resonance frequency at that time. Then, the data value based on the response signal from the IC card 2 based on the setting of the last resonance frequency for the resonance circuit 14 is stored in the built-in memory 11A, and the determination of "Is the last setting completed?" If "Y", the process ends.

When the collection of the data values from the IC card 2 is completed, the CPU 11 of the reader / writer 1 performs an operation on the data of each response signal stored in the built-in memory 11A, and has an optimum peak number and peak width. The set value of the resonance frequency is selected, and in the subsequent service processing, the selected resonance frequency is set in the resonance circuit 14 and oscillated.

FIG. 4 is a diagram for explaining how to select a resonance frequency generated from the resonance circuit 14 of the reader / writer 1. As described above, the built-in memory 11A of the CPU 11 of the reader / writer 1 stores one bit period of the response signal shown in FIG. 4 corresponding to the set value of the resonance frequency of the resonance circuit 11 (that is, the set value of the variable capacitor C2). Are stored. In this case, the CPU 11
In accordance with the set values of the two resonance frequencies, the peak width y is added for each peak to obtain an added value. Then, the largest one of the added values is selected as the resonance frequency of the resonance circuit 14. As a result, in the subsequent service processing, power can be supplied from the reader / writer 1 to the IC card 2 with high efficiency, so that data can be read from the IC card 2 and written to the IC card reliably. Can be.

[0023]

As described above, according to the present invention, the first resonance circuit includes the first resonance circuit, and the first resonance circuit includes the first resonance circuit.
A non-contact type IC card reader that electromagnetically couples with the second resonance circuit of the C card and supplies power to the IC card via the second resonance circuit, a variable means for changing the resonance frequency of the first resonance circuit; Adjusting means for controlling the variable means to adjust the resonance frequency of the first resonance circuit; detecting means for detecting the presence or absence of a response signal indicating that power has been supplied to the IC card after adjusting the resonance frequency of the adjusting means; A control unit that controls the adjustment unit to sequentially adjust the resonance frequency of the first resonance circuit, and selects an optimal response signal from the response signals detected by the detection unit; The resonance frequency according to the response signal thus set is set as the resonance frequency of the first resonance circuit.
Power can be efficiently supplied to the card to make it operable, and at this time, the operation of adjusting the first resonance circuit can be dispensed with. In addition, since the first resonance circuit includes the antenna having the inductive component and the capacitive element, the resonance frequency of the resonance circuit can be easily adjusted. Also,
When the second resonance circuit resonates based on the resonance frequency of the first resonance circuit adjusted by the adjustment unit, the IC card is supplied with power and generates a response signal including a plurality of pulses having a predetermined peak voltage and a predetermined peak width. Sending and controlling means,
Since the response signal having the largest peak width and the largest number of peaks is selected as the optimal response signal, the optimal resonance frequency can be selected and set. Further, when the second resonance circuit resonates based on the resonance frequency of the first resonance circuit adjusted by the adjustment means, power is supplied to the IC card, and the IC card responds after a lapse of a fixed time after the supply of the power. A signal is transmitted, and the control means determines that power is not supplied to the IC card if the response signal cannot be detected for a time longer than the predetermined time after adjusting the resonance frequency. It can be accurately determined that the battery is not supplied and is in an inoperative state.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a non-contact type IC card reader device according to the present invention.

FIG. 2 is a sequence diagram (FIG. 2A) showing an operation of a main part of the IC card reader, and a waveform diagram (FIG. 2B) of a response signal from the IC card.

FIG. 3 is a flowchart showing an operation of a main part of the IC card reader.

FIG. 4 is a diagram showing a selection situation of an optimum resonance frequency of the IC card reader device based on the response signal.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Reader / writer, 2 ... IC card, 11 ... CPU, 1
1A: memory, 11B: timer, 12: encoding circuit, 1
3: Modulation circuit, 14, 22: Resonance circuit, 15: Demodulation circuit, 16: Decoding circuit, 16: Power supply unit, 21: Control unit, C
1, C2: condenser, L: antenna.

Claims (4)

[Claims] A first resonance circuit that is electromagnetically coupled to a second resonance circuit of the IC card and supplies power to the IC card via the second resonance circuit; A variable means for varying a resonance frequency of the first resonance circuit; an adjustment means for controlling the variable means to adjust a resonance frequency of the first resonance circuit; Detecting means for detecting the presence or absence of a response signal indicating that power has been supplied to the IC card after adjusting the resonance frequency of the adjusting means; and controlling the adjusting means to sequentially adjust the resonance frequency of the first resonance circuit. And selecting an optimum response signal from among the response signals detected by the detection means every time the resonance frequency is adjusted by the adjustment means, and setting the resonance frequency according to the selected response signal to the first response signal. Contactless IC card reader being characterized in that a control means for setting the resonance frequency of the resonance circuit. 2. The antenna according to claim 1, wherein the first resonance circuit includes: an antenna having an inductive component;
A capacitive element provided as the variable means,
The non-contact type IC card reader device, wherein the adjusting means adjusts a resonance frequency of the first resonance circuit by changing a capacitance value of the capacitive element. 3. The IC card according to claim 1, wherein when the second resonance circuit resonates based on the resonance frequency of the first resonance circuit adjusted by the adjustment unit, the IC card is supplied with the power and a predetermined peak voltage is applied. And transmitting the response signal including a plurality of pulses having a peak width, wherein the control unit selects the response signal having the largest peak width and the largest number of pulses as the optimal response signal. Contactless IC card reader device. 4. The IC card according to claim 1, wherein when the second resonance circuit resonates based on the resonance frequency of the first resonance circuit adjusted by the adjustment unit, the power is supplied to the IC card and the IC card is supplied to the IC card. The card sends out the response signal after a lapse of a certain time after the supply of the power, and the control means detects the response signal for a time longer than the certain time after the resonance means adjusts the resonance frequency by the adjustment means. If it is not possible, it is determined that power is not supplied to the IC card.