JP2002251594A - Ic card and card reader device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an IC card capable of reducing costs. SOLUTION: This IC card 2 can mutually communicate with a card reader device 1 by receiving a high frequency signal SC1 transmitted by the card reader device 1 through an antenna part 21 arranged in an IC card main body, rectifying the high frequency signal SC1 to form an operating voltage, and demodulating a modulation signal superimposed on the high frequency signal SC1 . The antenna part 21 is constructed of a pair of electrostatic capacity coupling type antennas 21a and 21b separated from each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card and a card reader which can be accessed by a non-contact method.

[0002]

2. Description of the Related Art As a conventional IC card and a card reader which can be accessed by this kind of non-contact method, generally, an antenna coil is built in an IC card, and the card reader has a card reader. The antenna coil is arranged close to the antenna coil in the IC card inserted into the insertion slot.

In this conventional IC card and card reader device, the card reader device has an I
When the C card is inserted, the insertion of the IC card is detected, and a high-frequency signal generated by modulating a carrier signal with an access signal is transmitted from the antenna coil to the IC card. On the other hand, on the IC card side, a high-frequency signal transmitted from an antenna coil of the card reader device is received by a built-in antenna coil, and the received high-frequency signal is rectified to generate an access signal and a DC voltage. Next, the DC voltage is operated as operating power, and answer data for the access signal is transmitted to the card reader device. As a result, mutual communication is performed between the card reader device and the IC card.

[0004]

However, the conventional IC card and card reader have the following problems. That is, in the conventional IC card, in order to receive a high-frequency signal and generate sufficient operating power, the resonance frequency determined from the inductance of the antenna coil and the capacitance of the resonance capacitor accurately matches the frequency of the high-frequency signal. Need to be done. In this case, the resonance frequency is generally adjusted by finely adjusting the number of turns or the length of the antenna coil or finely adjusting the capacitance of the resonance capacitor. However, when the thickness is 0.8-0.
When the antenna coil is embedded in a thin IC card having a thickness of 9 mm and sealed, the inductance of the antenna coil greatly changes. For this reason, even if the antenna coil is manufactured by assuming the inductance change at the time of being incorporated, when the antenna coil is actually incorporated into the IC card, the assumed inductance change and the actual inductance change are different. May not match. In this case, an IC card in which the resonance frequency and the frequency of the high-frequency signal do not match in a sealed state must be discarded, and the yield is reduced accordingly. Therefore, the conventional IC card has a problem that its cost is soaring because it is difficult to accurately manufacture the inductance of the antenna coil.

The present invention has been made to solve such a problem, and an IC card capable of reducing costs.
And a card reader device capable of accessing the IC card.

[0006]

In order to achieve the above object, an IC card according to the present invention receives a high-frequency signal transmitted by a card reader device via an antenna section provided in an IC card main body, and receives the high-frequency signal. An IC card configured to rectify a high-frequency signal to generate an operating voltage and to communicate with the card reader device by demodulating a modulation signal superimposed on the high-frequency signal, The antenna unit includes a pair of capacitively coupled antennas separated from each other.

According to a second aspect of the present invention, there is provided an IC card according to the first aspect, wherein the pair of capacitively coupled antennas are arranged on the outer surface of the card body along a longitudinal direction of the card body. It is characterized by the following.

According to a third aspect of the present invention, there is provided the IC card according to the first or second aspect, wherein the pair of capacitively coupled antennas are disposed on a surface of the IC card main body and separated from each other. A first metal thin film and a second metal thin film, and a third metal thin film and a fourth metal thin film provided on a back surface of the IC card main body and separated from each other; Thin film and third
Are connected to each other with the IC card body interposed therebetween and constitute one of the capacitively coupled antennas. The second metal thin film and the fourth metal thin film are It is characterized by being opposed to each other across a card body and connected to each other to form the other capacitively coupled antenna.

According to a fourth aspect of the present invention, in the IC card according to the second or third aspect, the IC card body is provided with a rust-proof coating on a surface on which the capacitive coupling antenna is formed. It is characterized by the following.

A card reader according to a fifth aspect is a card reader configured to be able to communicate with the IC card according to any one of the first to fourth aspects,
A pair of device-side capacitance-coupling antennas respectively disposed so as to be able to face the pair of capacitance-coupling antennas in the card, and the device-side capacitance-coupling antenna and the pair of IC card-side antennas. The high-frequency signal is transmitted to the IC card via a capacitive coupling antenna.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an IC card and a card reader according to the present invention will be described below with reference to the accompanying drawings.

The card reader / writer 1 corresponds to the card reader in the present invention, and supplies power by transmitting a high-frequency signal to the IC card 2 by an electrostatic capacitance coupling method as shown in FIG. And IC card 2
It is configured to be able to access an EEPROM described later. Specifically, the card reader / writer 1 includes an oscillation circuit 11, a modulation circuit 12, a detection circuit 13, and an amplification circuit 14.
And an antenna unit 15.

In this case, the oscillation circuit 11 includes the IC card 2
In order to enhance the degree of capacitance coupling with the carrier, a carrier wave Sc (see FIG. 4) of a higher frequency, for example, 18 MHz is generated and output to the modulation circuit 12. The modulation circuit 12 amplitude-modulates the carrier Sc in synchronization with a modulation signal SMA (see FIG. 4) such as control data output from a personal computer (hereinafter, also referred to as a “personal computer”) arranged outside. In this case, the modulation signal SMA has a duty ratio of 5
It consists of 0% serial data. Therefore, I
To enable the C card 2 to generate sufficient power, the modulation circuit 12 generates a modulation signal SMB (see FIG. 4) having a pulse width of, for example, 15 μ in synchronization with the modulation signal SMA, and modulates the modulation signal. The high frequency signal SC1 shown in FIG. 4 is generated by amplitude modulating the carrier Sc with the signal SMB. The detection circuit 13 rectifies the high-frequency signal SC2 (see FIG. 4) when the carrier wave Sc is amplitude-modulated by the IC card 2, thereby obtaining a demodulated signal SD2 as answerback data.
(See FIG. 4). The amplifier circuit 14 includes, for example, an operational amplifier, amplifies the demodulated signal SD2, and outputs the demodulated signal SD3 shown in FIG. 4 to a personal computer. Antenna unit 15
Are provided with a pair of non-contact type capacitive coupling type antennas 15a and 15b,
a is connected to the output terminal of the modulation circuit 12, and the other antenna 15b is connected to the ground potential (earth potential). When the modulation circuit 12 is configured to output the high-frequency signal SC1 in a balanced manner, the antenna 15a,
15b is connected. Also, the antennas 15a, 15
The structure of b will be described later.

On the other hand, the IC card 2 includes a transmitting / receiving antenna unit 21, a diode stack 22 as a rectifier circuit,
The circuit includes a voltage stabilizing circuit 23, a control circuit 24, a demodulation circuit 25, and a modulation circuit 26. In this case, as shown in FIGS.
Are formed on both sides of the card body. Specifically, the antenna unit 21 is, for example, a capacitive coupling formed by a metal foil (metal thin film) such as aluminum deposited on the front and back surfaces of the card body with a thickness of about several tens of microns (eg, 15 μm). Antenna 21a (first metal thin film), 21b (second metal thin film), 21c (third metal thin film), and 21d (fourth metal thin film). In this case, the antennas 21a and 21b are each formed in a long and substantially rectangular shape along the longitudinal direction of the card body, and are arranged side by side on the surface of the card body in a state where they are separated from each other with a slight gap. Also, the antenna 21
c and 21d are the same as the antennas 21a and 21b,
The antennas 21a, 21a, 21a, 21b are formed in a substantially rectangular shape that is long along the longitudinal direction of the card body, are separated from each other with a slight gap therebetween, and sandwich the IC card body.
21b, they are arranged side by side on the back surface of the card body. Further, the antennas 21a and 21c
The antenna 21 is short-circuited and connected to each other inside the C card 2.
b and 21d are also short-circuited to each other inside the IC card 2. On the other hand, the antennas 15a and 15b on the card reader / writer 1 side are formed of, for example, a thin metal plate, and the antennas 21a and 15a of the inserted IC card 2 are used.
21b (or 21c, 21d) is disposed so as to face the surface. In this case, the antenna 15a
(Or 15b) and the antenna 21a (or 21b) are coupled at about 100 PpF. Note that the IC card 2 is designed to prevent rust from being generated on the antennas 21a to 21d.
The front and back surfaces on which the antennas 21a to 21d are formed are coated with, for example, resin. Therefore,
Even if rainwater adheres to the IC card 2, the antennas 21a to 21d can be prevented from being corroded.
Durability can be improved.

In this IC card 2, antennas 21a and 21b are provided on the front surface, and the antenna 21a is provided on the back surface.
Since c and 21d are provided, the front and back sides can be inserted into the card insertion slot without distinction, and the antenna unit 21 reliably receives the high-frequency signal SC1 regardless of whether the front or back side is inserted upward. I do. Note that the antennas 21a and 21b can be provided on only one of the front and back sides. However, when the IC card 2 is inserted into the card slot with one of the front and back facing upward, the thickness of the IC card 2 (0.8 to
The antenna unit 15 is separated from the antenna unit 21 by 0.9 mm). Therefore, the capacitance coupling between the antenna unit 15 and the antenna unit 21 is weakened, and the reception level of the high frequency signal SC1 by the IC card 2 is reduced. Therefore, in order to generate sufficient operating power on the IC card 2 side, it is preferable to adopt the configuration of the IC card 2. Further, the IC card 2 is usually inserted along its longitudinal direction. For this reason, the antennas 21a to 21d are arranged side by side along the width direction of the IC card 2 and the antennas 21a and 21b (or 21c and 21d) of the IC card 2 inserted into the card insertion slot of the card reader / writer 1
In the case where the antennas 15a and 15b of the antenna unit 15 are arranged so as to face each other, when the IC card 2 is inserted into the card insertion slot, the antenna 15a (or 15b) of the antenna unit 15 and the antenna There is a possibility that both antennas 21a and 21b of the unit 21 may overlap and cause a short circuit state. Therefore, when such a configuration is adopted, in order to avoid the overlap between the antenna 15a (or 15b) and the two antennas 21a and 21b of the antenna unit 21,
High alignment accuracy is required. For this reason, it is preferable to arrange the antennas 21a to 21d side by side along the insertion direction of the IC card 2.

The diode stack 22 generates a DC signal SDC shown in FIG. 4 by full-wave rectifying the high-frequency signal SC1 transmitted by the card reader / writer 1, and converts the generated DC signal SDC to a voltage stabilizing circuit 23 and Output to the demodulation circuit 25. The voltage stabilizing circuit 23 stabilizes the DC signal SDC and supplies a DC voltage as operating power to the control circuit 24. The control circuit 24 is actually an CPU (Electrically Erasable PR) storing various data and reading and rewriting the stored data by the card reader / writer 1.
OM) and a ROM for storing a program for operating the CPU
And a RAM for temporarily storing various data. The demodulation circuit 25 demodulates the DC signal SDC and outputs it to the control circuit 24 as a demodulated signal SD1. In this case, the demodulated signal SD1 has substantially the same waveform as the modulated signal SMB. Note that a configuration in which the DC signal SDC is output to the control circuit 24 as the demodulated signal SD1 without providing the demodulation circuit 25 may be employed. The modulation circuit 26 outputs an output signal SO as answerback data output from the control circuit 24.
By short-circuiting the output end of the diode stack 22 in synchronization with (see FIG. 4), the carrier Sc (that is, the unmodulated high-frequency signal SC1) in the antenna 15a of the card reader / writer 1 is amplitude-modulated.

Next, an IC in the card reader / writer 1
The communication process for the card 2 will be described with reference to FIG.

At the time of waiting for access from the IC card 2, in the card reader / writer 1, the modulation circuit 12 intermittently outputs, for example, an unmodulated high-frequency signal SC1 to the antenna 15a, and at the same time, the antenna section 15 Send SC1 intermittently. Next, when the IC card 2 is inserted into the card insertion slot, the antennas 15a and 15b and the IC
The antennas 21a, 21b (or 21c,
21d) are opposed to each other, whereby the antenna unit 21 receives the high-frequency signal SC1. At this time, in the IC card 2, the voltage stabilizing circuit 23 outputs a DC voltage obtained by stabilizing the DC signal SDC generated by the diode stack 22 to the control circuit 24.

Subsequently, the control circuit 24 outputs insertion confirmation data for notifying the card reader / writer 1 of the insertion to the modulation circuit 26 as an output signal SO shown in FIG.
Next, the modulation circuit 26 short-circuits the output terminal of the diode stack 22 in synchronization with the output signal So. That is, the load impedance of the diode stack 22 is changed. As a result, the impedance of the output terminal of the modulation circuit 12 fluctuates via the antenna units 21 and 15, so that the high-frequency signal SC2 at the output terminal is synchronized with the output signal SO as shown in the voltage waveform of FIG. Amplitude modulated. Thereafter, the detection circuit 13 detects the high-frequency signal SC2 to generate the demodulated signal SD2 shown in FIG.
Output to Next, the amplifier circuit 14 outputs a demodulated signal SD3 (see FIG. 7) obtained by amplifying the demodulated signal SD2 with a predetermined gain to a personal computer.

On the other hand, the personal computer that has detected the insertion of the IC card 2 outputs access data to the IC card 2 to the card reader / writer 1 as a modulation signal SMA shown in FIG. At this time, the modulation circuit 12 generates the modulation signal SMB shown in FIG. 3 in synchronization with the modulation signal SMA, and modulates the carrier Sc (see FIG. 4) output from the oscillation circuit 11 with the modulation signal SMB. The high-frequency signal SC1 shown in FIG. Thus, the high-frequency signal SC1 is transmitted to the IC card 2 via the antenna units 15 and 21 that are capacitively coupled to each other.

In the IC card 2, the diode stack 2
2 generates a DC signal SDC shown in FIG. Next, the demodulation circuit 25 demodulates the DC signal SDC into a demodulated signal SD1 and outputs the demodulated signal to the control circuit 24. Accordingly, the CPU in the control circuit 24 executes rewriting of balance information and the like recorded in the EEPROM and transfer of customer information and balance information to the card reader / writer 1 in accordance with the contents of the access data. Also, C
The PU temporarily stores the rewriting information for rewriting the balance information and the like in the RAM as necessary.

On the other hand, when transferring customer information and the like, the CPU in the control circuit 24 outputs transfer data such as customer information to the modulation circuit 26 as an output signal SO shown in FIG. At this time, the modulation circuit 26 synchronizes with the output signal So in the same manner as the operation described above,
2 is short-circuited. As a result, the antenna unit 21,
15, the impedance of the output terminal of the modulation circuit 12 fluctuates, so that the high-frequency signal SC2 at the output terminal
As in the voltage waveform shown in FIG. 4, the amplitude is modulated in synchronization with the output signal So. Next, the detection circuit 13 detects the high-frequency signal SC2 to demodulate it into a demodulated signal SD2 shown in FIG. Thereafter, the amplifier circuit 14 amplifies the demodulated signal SD2 and outputs it to the personal computer. As described above, customer information and balance information in the IC card 2 are transferred to the personal computer.

As described above, according to the card reader / writer 1 and the IC card 2, the antenna units 15 and 21 capable of transmitting and receiving high-frequency signals to and from each other by capacitive coupling are used. Compared with the method used, the operation of adjusting the resonance frequency of the antenna section can be made unnecessary, so that the IC card 2 can be manufactured extremely simply and at low cost.

Although the embodiment of the present invention has been described with respect to an example in which the antenna unit 21 is provided on the outer surface of the IC card 2, the antenna unit 21 may be provided inside the card body of the IC card 2. Can also. However, in order to bring the antenna unit 15 closer to the antenna unit 15 of the card reader / writer 1, it is preferable to dispose the antenna unit 21 on the outer surface. Also, an example has been described in which amplitude modulation is used as a modulation method for communication between the card reader / writer 1 and the IC card 2, but the modulation method itself is not limited.
Various modulation methods such as phase modulation can be adopted. Further, the configuration of each circuit of the card reader / writer 1 and the IC card 2 is not limited to the configuration shown in the embodiment of the present invention.
Needless to say, it can be appropriately changed.

[0025]

As described above, according to the IC card of the first aspect, since the antenna section is constituted by the pair of capacitively coupled antennas separated from each other, the pair of capacitances is provided to the card reader device. Just providing a coupled antenna,
High frequency signals can be transmitted and received reliably and easily between the card reader device and the IC card. Therefore, the operation of adjusting the resonance frequency of the antenna unit can be made unnecessary, so that the IC card can be manufactured extremely simply and at low cost.

According to the second aspect of the present invention, the pair of capacitively coupled antennas are arranged along the longitudinal direction of the card body and on the outer surface of the card body, so that the antennas extend in the width direction of the IC card. As compared with the configuration in which the antenna unit is arranged side by side, since the positioning accuracy when inserting the IC card into the card insertion slot of the card reader device is not so required, the card insertion slot of the card reader device can be configured easily. Reliable communication between the IC card and the card reader device can be ensured.

Further, according to the third aspect of the present invention, since a pair of metal thin-film capacitive coupling antennas is provided on the front and back surfaces of the IC card, reliable connection between the IC card and the card reader device is ensured. It is possible to insert the IC card into the card insertion slot of the card reader without discriminating the front and back sides while ensuring communication.

According to the fourth aspect of the present invention, the surface of the IC card body on which the capacitive coupling antenna is formed is provided with a rust-preventive coating, so that rainwater adheres to the IC card. Even so, the corrosion of the capacitively coupled antenna can be prevented, so that the durability can be improved.

According to a fifth aspect of the present invention, there is provided a card reader having a pair of device-side capacitive coupling antennas which are disposed so as to be opposed to a pair of capacitive coupling antennas in an IC card. Accordingly, it is possible to increase the reliability of mutual communication with the IC card while having a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram of a card reader / writer 1 and an IC card 2 according to an embodiment of the present invention.

FIG. 2 is a plan view of the IC card 2 according to the embodiment of the present invention.

FIG. 3 is a side view of the IC card 2 according to the embodiment of the present invention.

FIG. 4 is a signal waveform diagram in each part of the card reader / writer 1 and the IC card 2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Card reader / writer 2 IC card 15, 21 Antenna part 15a, 15b, 21a-21d Antenna SC1 High frequency signal

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 13/08 H01Q 21/24 5J046 21/24 H04B 5/02 5K012 H04B 5/02 G06K 19/00 HF Term (reference) 2C005 MA18 MA19 NA10 5B035 AA04 BA05 BB09 CA12 CA23 5B058 CA15 KA02 KA04 KA24 5J021 AA01 AA02 AA09 AB06 CA06 GA08 HA05 HA10 JA07 5J045 AA21 AB05 DA10 EA07 FA02 NA01 5J046 AA04 ACA AB13

Claims (5)

[Claims] A high-frequency signal transmitted by a card reader device is received via an antenna unit provided in an IC card body, the high-frequency signal is rectified to generate an operating voltage, and is superimposed on the high-frequency signal. An IC card configured to be able to communicate with the card reader device by demodulating a modulated signal, wherein the antenna unit includes a pair of capacitively coupled antennas separated from each other. An IC card, comprising: 2. The pair of capacitively coupled antennas,
2. The IC card according to claim 1, wherein the IC card is arranged on an outer surface of the card body along a longitudinal direction thereof. 3. The pair of capacitively coupled antennas,
A first metal thin film and a second metal thin film provided on a surface of the IC card main body and separated from each other;
A third metal thin film and a fourth metal thin film provided on the back surface of the C card body and separated from each other, wherein the first metal thin film and the third metal thin film are provided in the IC card body. And the other is connected to each other to constitute one of the capacitively coupled antennas, and the second metal thin film and the fourth metal thin film are opposed to each other across the IC card body. 3. The IC according to claim 1, wherein the IC is connected to each other to form the other capacitively coupled antenna. 4.
card. 4. The IC card according to claim 2, wherein the IC card body has a rust-proof coating on a surface on which the capacitive coupling antenna is formed. 5. The IC according to claim 1, wherein
A card reader device configured to be able to communicate with a card, comprising: a pair of device-side capacitive coupling antennas respectively disposed so as to be able to face the pair of capacitive coupling antennas in the IC card. A card reader device for transmitting the high-frequency signal to the IC card via the device-side capacitive coupling antenna and the pair of capacitive coupling antennas on the IC card side.