JP3699843B2 - Non-contact type IC card reader device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a non-contact type IC card reader device for recording / reproducing data to / from a non-contact type IC card.
[0002]
[Prior art]
This kind of non-contact type IC card reader device is provided with a resonance circuit composed of an antenna having an inductive component and a capacitor. The antenna of this resonance circuit and the antenna of the resonance circuit of the non-contact type IC card are provided. Are electromagnetically coupled to supply power to the IC card from the IC card reader device.
Here, power is efficiently supplied from the IC card reader device to the IC card by bringing the resonance frequencies of the IC card reader device and the resonant circuits of the IC card closer to each other.
[0003]
[Problems to be solved by the invention]
By the way, in the conventional IC card reader device, the resonance frequency that matches the resonance frequency of the resonance circuit of the card when the distance from one IC card is set to 5 mm, for example, 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). Therefore, power is not efficiently supplied to the IC card, and in some cases, operable power may not be supplied to the IC card.
[0004]
In addition, such an IC card reader device can be processed even when a plurality of IC cards are placed at the same time. However, when such a plurality of IC cards are placed, a plurality of IC cards can be loaded. Since the resonance frequency on the IC card side changes, the IC card may not operate in such a case.
Therefore, an object of the present invention is to efficiently supply power to an IC card so that the IC card can be operated.
[0005]
[Means for Solving the Problems]
In order to solve such a problem, the present invention includes a first resonance circuit, and the first resonance circuit is electromagnetically coupled to the second resonance circuit of the IC card and is connected to the IC via the second resonance circuit. In a non-contact type IC card reader device for supplying power to a card, variable means for changing the resonance frequency of the first resonance circuit, and adjustment means for adjusting the resonance frequency of the first resonance circuit by controlling the variable means And detecting means for detecting presence / absence of a response signal indicating that power is 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. The optimum response signal is selected from the response signals detected by the detection means for each adjustment of the resonance frequency of the adjustment means, and the resonance frequency corresponding to the selected response signal is set as the resonance frequency of the first resonance circuit. And a control means for setting the IC card, and when the second resonance circuit resonates based on the resonance frequency of the first resonance circuit adjusted by the adjustment means, the IC card is supplied with power and has a predetermined peak voltage and peak width. A signal composed of a plurality of pulses is sent as a response signal , and the control means selects a response signal whose peak voltage and peak width conform to the standard as an optimum response signal.
The first resonance circuit includes an antenna having an inductive component and a capacitive element provided as the variable means, and the adjustment means changes the resonance frequency of the first resonance circuit by changing the capacitance value of the capacitive element. To be adjusted.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
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 device according to the present invention. This non-contact type IC card reader device (hereinafter referred to as reader / writer 1) is electromagnetically coupled to the non-contact type IC card 2 to supply power to the IC card 2 and to transfer data to the IC card 2 activated by power supply. Recording and reproduction are performed.
[0007]
The reader / writer 1 is called a CPU 11, an encoding circuit 12 called a modified mirror code encoding circuit that encodes data supplied from the CPU 11, and an ASK100 modulation circuit that modulates encoded data from the encoding circuit 12. A modulation circuit 13; a resonance circuit 14 in which an antenna L made of an inductive component and capacitors C1 and C2 are connected in parallel; a demodulation circuit 15 called an ASK demodulation circuit that demodulates data from the IC card 2 via the resonance circuit 14; A decoding circuit 16 called a Manchester code decoding circuit that decodes demodulated data from the demodulation circuit 15 and a power supply unit 17 that supplies power to each of 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.
[0008]
By the way, the resonance circuit 14 of the reader / writer 1 supplies power from the power supply unit 17 when the IC card 2 is mounted at a predetermined mounting location and an operation unit (not shown) is operated to start a predetermined service. And oscillates at a frequency (resonance frequency) determined by each value of the antenna L and 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 extracted as a DC voltage by a rectifier circuit (not shown). Is supplied as an operating power source.
[0009]
Here, when the reader / writer 1 reads the data of 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. This 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 this modulation 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 this is detected, the control unit 21 reads out data from an internal memory (not shown) and sends the data to an encoding circuit (not shown) for encoding (Manchester code). This 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 this circuit 22 and sent 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, further decoded by the decoding circuit 15, and sent to the CPU 11. Thereby, the CPU 11 can read the data of the IC card 2.
[0010]
On the other hand, when the reader / writer 1 updates the data of the IC card 2 after the service is completed, the update data is sent from the CPU 11 to the encoding circuit 12. This 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 this modulation 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).
[0011]
FIG. 2A is a sequence diagram showing the operation of the main part of the present invention, in which the operation state of the IC card 2 is checked on the reader / writer 1 side.
As described above, when the IC card 2 is placed at a predetermined placement location 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 starting, the power supply unit 17 receives power supply and oscillates at a resonance frequency determined by the values of the antenna L and the capacitors C1 and C2.
That is, the CPU 11 of the reader / writer 1 supplies power from the power supply unit 17 to the resonance circuit 14, changes the value of the variable capacitor C2 of the resonance circuit 14, and sets the resonance circuit 14 to oscillate at the resonance frequency A. A response request is made to the IC card 2 (step S1). Then, the resonance circuit 14 oscillates at the resonance frequency A. When the resonance circuit 22 of the IC card 2 oscillates (resonates) due to the oscillation of the resonance circuit 14 and power is supplied to the control unit 21, the control unit 21 determines in advance from the start point based on the power supply. A response signal is returned to the reader / writer 1 via the resonance circuit 22 after about 0.3 ms (32 × 128 / 13.56 MHz).
[0012]
Here, if the frequency bands of 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, the resonance circuit 22 of the IC card 2 does not sufficiently oscillate, and therefore the control unit 21 does not vibrate. Is not supplied with operable power. For this reason, the control unit 21 does not operate, and no response signal is returned from the IC card 2 even when 0.3 ms has elapsed (step S2).
The CPU 11 of the reader / writer 1 does not return a response signal from the IC card 2 even when 0.3 ms + α time has elapsed, so this time, the capacitance value of the variable capacitor C2 of the resonance circuit 14 is set to a new capacitance value, and the resonance occurs. A setting is made to oscillate the circuit 14 at the resonance frequency B, and a response request is sent to the IC card 2 (step S3). Then, the resonance circuit 14 oscillates at the resonance frequency B, and a radio signal having the resonance frequency B is transmitted to the IC card 2 side.
[0013]
In this case, assuming that the frequency bands of the resonance frequency B of the resonance circuit 14 of the reader / writer 1 and the resonance frequency of the resonance circuit 22 of the IC card 2 substantially coincide, the resonance circuit 22 of the IC card 2 starts oscillation (resonance). Then, the operating power is supplied to the control unit 21 by this oscillation, 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 when 0.3 ms has elapsed from the activation point (step S4).
The CPU 11 of the reader / writer 1 receives this response signal directly from the demodulation circuit 15 as a Manchester code shown in FIG. 2B without passing through the decoding circuit 16. The number and 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 in which the resonance frequency B is set (the variable capacitor C2). (Capacity setting value) and a pair (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 number of peaks 3 and the peak width 4 (the unit of the peak width is, for example, μsec) are stored in the built-in memory 11A in association with the setting data b.
[0014]
In this way, the resonance frequency of the resonance circuit 14 is sequentially changed, and the peak number and peak width of the Manchester code included in the response signal from the IC card 2 are input and stored together with the setting data of the variable capacitor C2 in the built-in memory 11A. .
Finally, the CPU 11 makes a setting n request for supplying power to the resonance circuit 14 from the power supply unit 17 and causing the resonance circuit 14 to oscillate at the resonance frequency N (step S6), and causes the resonance circuit 14 to oscillate at the resonance frequency N. As a result, the resonance circuit 22 of the IC card 2 oscillates in the same manner, and the power is supplied to the control unit 21 and activated by this oscillation. The activated control unit 21 similarly returns a response signal to the reader / writer 1 when 0.3 ms has elapsed since the activation (step S7).
[0015]
When the CPU 11 of the reader / writer 1 receives this response signal as a Manchester code, it similarly stores the number of peaks and the peak width in the built-in memory 11A in pairs with the setting data n for the capacitor C2 in which the resonance frequency N is set ( Step S8). In the example of FIG. 2A, the peak number 4 and the peak width 8 are stored in the built-in memory 11A in association with the setting data n.
The CPU 11 of the reader / writer 1 selects the setting data having the largest peak number and peak width from the peak number and peak width of the response signal thus stored in the built-in memory 11 A, and this setting data is stored in the resonance circuit 14. It is set as the capacitance value of the variable capacitor C2. As a result, in subsequent service processing, power can be supplied from the reader / writer 1 to the IC card 2 with high efficiency. Therefore, the IC card 2 is reliably operated to read data from the IC card 2 or to the IC card. Can be written.
[0016]
FIG. 3 is a flowchart of the CPU 11 of the reader / writer 1 summarizing the operation shown in FIG. 2A for supplying power to the IC card 2.
When the IC card 2 is placed at a predetermined place and a start instruction operation for a predetermined service process using the IC card 2 is performed, the CPU 11 first resonates 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 transmits a radio signal having this frequency to the IC card 2 as a response request signal (step S12).
[0017]
At the same time, the CPU 11 starts the internal timer 11B by setting the time of 0.3 ms + α (step S13).
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 step S14 and step S15, respectively. The number of peaks, the width of each peak, and the voltage are stored in the built-in memory 11A together with the set value of the resonance frequency (that is, the capacitance set value of the variable capacitor C2) (step S16). When the built-in timer 11B times out before receiving the response signal, the data without the response signal is stored in the built-in memory 11A together with the set value of the resonance frequency (step S16).
[0018]
When the data is stored in the built-in memory 11A, the CPU 11 temporarily stops supplying power to the resonance circuit 14, and determines whether or not the last resonance frequency is set for the resonance circuit 14 in step S17. In this case, the first time Since the setting is made, the process returns to step S11 to supply power to the resonance circuit 14 from the power supply unit 17, and at the same time, change the capacitance of the variable capacitor C2 to the next new capacitance value, thereby changing the resonance frequency of the resonance circuit 14 to a new resonance. Set to frequency.
Then, the resonance circuit 14 starts oscillation 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.
[0019]
Thereafter, the CPU 11 similarly 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 step S14 and step S15, respectively, and if a response signal is received before the timeout of the built-in timer 11B, the response The number of signal peaks, the width of each peak, and the voltage are stored in the built-in memory 11A together with the set value of the resonance frequency (step S16). When the built-in timer 11B times out before receiving the response signal, the data without the response signal is stored in the built-in memory 11A together with the set value of the resonance frequency (step S16).
[0020]
In this manner, the CPU 11 sequentially changes the resonance frequency of the resonance circuit 14 to oscillate, and the peak number, peak width, and peak voltage value of the response signal returned from the IC card 2 together with the set value of the resonance frequency at that time are stored in the built-in memory. Store in 11A. 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?” When “Y”, the process ends.
[0021]
When the collection of data values from the IC card 2 is completed, the CPU 11 of the reader / writer 1 calculates the response signal data stored in the built-in memory 11A, and obtains the resonance frequency having the optimum number of peaks and peak width. A set value is selected, and in the subsequent service processing, the selected resonance frequency is set in the resonance circuit 14 and oscillated.
[0022]
FIG. 4 is a diagram for explaining a selection state of the resonance frequency generated from the resonance circuit 14 of the reader / writer 1.
In the built-in memory 11A of the CPU 11 of the reader / writer 1, the 1-bit period of the response signal shown in FIG. 4 corresponds to the set value of the resonance frequency of the resonance circuit 11 (that is, the set value of the variable capacitor C2) as described above. The peak width y and the number of peaks are stored.
In this case, the CPU 11 obtains an added value by adding the peak width y for each peak corresponding to the set value of one resonance frequency. Then, the maximum value of the added value is selected as the resonance frequency of the resonance circuit 14. As a result, in subsequent service processing, power can be supplied from the reader / writer 1 to the IC card 2 with high efficiency. Therefore, data reading from the IC card 2 and data writing to the IC card are surely performed. Can do.
[0023]
【The invention's effect】
As described above, according to the present invention, the first resonance circuit is provided, and the first resonance circuit is electromagnetically coupled to the second resonance circuit of the IC card and is connected to the IC card via the second resonance circuit. In a non-contact type IC card reader device for supplying power, a variable means for changing the resonance frequency of the first resonance circuit, an adjustment means for adjusting the resonance frequency of the first resonance circuit by controlling the variable means, Detection means for detecting the presence or absence of a response signal indicating that power is supplied to the IC card after adjustment of the resonance frequency, and control means are provided. The control means controls the adjustment means to control the resonance frequency of the first resonance circuit. Are sequentially adjusted, and an optimum response signal is selected from the response signals detected by the detection means, and the resonance frequency corresponding to the selected response signal is set as the resonance frequency of the first resonance circuit. Because it was Unishi, it becomes possible to allow the operation to efficiently supply power to the IC card, in this case can be made unnecessary adjustment of the first resonant circuit.
In addition, since the first resonance circuit is composed of an antenna having an inductive component and a capacitive element, the resonance frequency of the resonance circuit can be easily adjusted.
In addition, when the second resonance circuit resonates based on the resonance frequency of the first resonance circuit adjusted by the adjusting means, the IC card is supplied with power and a response comprising a plurality of pulses having a predetermined peak voltage and peak width. Since the signal is transmitted and the control means selects the response signal having the largest peak width and the largest number of peaks as the optimum response signal, the optimum resonance frequency can be selected and set.
In addition, 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 certain period of time has elapsed since the power supply. Since the signal is transmitted and the control means determines that no power is supplied to the IC card when the response signal cannot be detected for a time longer than the predetermined time after adjusting the resonance frequency, the IC card has sufficient power. It is possible to accurately determine that the device is in an inoperative state without being supplied.
[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 device and a waveform diagram of a response signal from the IC card (FIG. 2B).
FIG. 3 is a flowchart showing the main operation of the IC card reader device.
FIG. 4 is a diagram showing a selection state 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, 11A ... Memory, 11B ... Timer, 12 ... Encoding circuit, 13 ... Modulation circuit, 14, 22 ... Resonance circuit, 15 ... Demodulation circuit, 16 ... Decoding circuit, 16 ... Power supply unit, 21 ... Control unit, C1, C2 ... Capacitor, L ... Antenna.

Claims (2)

A non-contact type IC comprising a first resonance circuit, wherein the first resonance circuit is electromagnetically coupled to a second resonance circuit of an IC card and supplies power to the IC card via the second resonance circuit In the card reader device,
Variable means for varying the resonant frequency of the first resonant circuit;
Adjusting means for controlling the variable means to adjust the resonant frequency of the first resonant circuit;
Detecting means for detecting the presence or absence of a response signal indicating that power is supplied to the IC card after adjusting the resonance frequency of the adjusting means;
The adjustment means is controlled to sequentially adjust the resonance frequency of the first resonance circuit, and an optimum response signal is selected from the response signals detected by the detection means for each adjustment of the resonance frequency of the adjustment means. Control means for selecting and setting a resonance frequency according to the selected response signal as the resonance frequency of the first resonance circuit;
When the second resonance circuit resonates based on the resonance frequency of the first resonance circuit adjusted by the adjusting means, the IC card is supplied with the power and comprises a plurality of pulses having a predetermined peak voltage and peak width. It sends a signal as the response signal,
Wherein, the non-contact type IC card reader, characterized by selecting the number of most multi prestige No. of the peak width is the largest and the pulse as best response signal the. In claim 1,
The first resonance circuit includes an antenna having an inductive component and a capacitive element provided as the variable means, and the adjustment means changes the capacitance value of the capacitive element to change the capacitance of the first resonance circuit. A non-contact type IC card reader device characterized by adjusting a resonance frequency.

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