JPH10302032A - Reader / writer for non-contact IC card - Google Patents

Abstract

(57) [Problem] To provide a reader / writer for a non-contact IC card, which has a built-in mechanism for adjusting the intensity of transmission / reception radio waves. SOLUTION: A reader / writer 1 is controlled by a CPU 2 and internally stores various data in ROM3, RAM4.
have. Communication I / F with host computer 27
Communication is performed by the circuit 5. When transmitting data to the IC card, the synchronization signal of the transmitter 7 is modulated in the modulator 8 by the data transmitted through the communication I / F circuit 6, amplified by the driver 9, and then transmitted through the resonance capacitor 10. , From the transmitting antenna 11 composed of a coil. At the time of reception from the IC card, the filter 13 removes unnecessary frequency components from the data received by the reception antenna 14 and
After the demodulation, the data is sent to the CPU 2 via the communication I / F circuit 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a reader / writer for a non-contact IC card, which has a built-in mechanism for adjusting the intensity of radio waves transmitted and received.

[0002]

2. Description of the Related Art In recent years, a non-contact IC card system (hereinafter, referred to as an IC card system) including a non-contact IC card (hereinafter, referred to as an IC card) and a reader / writer for the IC card (hereinafter, referred to as a reader / writer). Has progressed, and some have reached the practical stage. In the inspection at the time of manufacturing the IC card used in the above IC card system,
A reader / writer is used to evaluate the performance and confirm the operation. In that case, as an example, the communication distance is 50c.
m, the distance between the reader / writer and the IC card under test must be minimized in order to evaluate the performance near the boundary between the area where the system operates stably and the area where the operation is unstable. 50cm or more must be secured. For this reason, the longer the communication distance of the system, the longer the distance between the reader / writer and the IC card in consideration of the error of the performance evaluation test. Therefore, performance evaluation in a test environment where a sufficient distance cannot be obtained can be performed only in a stable operation area near the reader / writer, and it is difficult to perform evaluation closer to the actual use environment.

Next, a conventional technique will be described with reference to FIG. In this figure, reference numeral 1 denotes a reader / writer. Reference numeral 2 denotes a CPU (Central Processing Unit), which controls reading and writing of memory in the reader / writer 1, processing of data, control of communication with an IC card, and the like. Symbol 3 is RO
M is a read only memory, and reference numeral 4 is a RAM (random access memory). Reference numeral 27 denotes a host computer which communicates with the reader / writer 1 via the communication I / F circuit 5. Reference numeral 6 denotes a communication I / F circuit that performs interface processing when the reader / writer communicates with the IC card. Reference numeral 7 denotes an oscillator (OSC),
A synchronization signal used inside the reader / writer 1 is generated.
A modulator 8 modulates a synchronization signal supplied from the transmitter 7 with data supplied from the communication I / F circuit 6.

[0004] Reference numeral 9 denotes a driver, which amplifies the output signal of the modulator 8 and amplifies the output signal.
And a transmission antenna 11 formed of a coil. The oscillation frequency of this series resonance circuit is determined from the values of the resonance capacitor 10 and the coil. Therefore, the capacitance of the resonance capacitor is determined from the carrier frequency to be transmitted and the value of the coil. The output signal of the modulator 8 passes through this series resonance circuit,
Finally, it is output to the outside of the reader / writer 1 as an electromagnetic wave. Reference numeral 14 denotes a receiving antenna. Reference numeral 13 denotes a filter, which removes unnecessary frequency components of the electromagnetic wave received by the receiving antenna 14. A demodulator 12 demodulates the output signal of the filter 13 and outputs the demodulated signal via the communication I / F circuit 6 to the CP.
Sent to U2. Reference numeral 18 denotes an IC card having the following blocks as its internal circuit. Reference numeral 19 denotes a receiving antenna, and reference numeral 23 denotes a transmitting antenna. Reference numeral 20 denotes a power supply, which rectifies the AC signal received from the receiving antenna 19 and supplies a DC voltage to each part in the IC card. The power supply 20 enables the IC card 18 to operate with power supplied from the reader / writer 1 without power.

[0005] Reference numeral 21 denotes a clock generator, which extracts a synchronization clock from a signal supplied from the receiving antenna 19. A demodulator 22 demodulates a signal supplied from the receiving antenna 19. Reference numeral 26 denotes a rewritable nonvolatile memory, which stores data necessary for processing. Reference numeral 25 denotes an I / O control circuit,
The memory 26 according to the signal demodulated by the demodulator 22
The data read / write control is performed on the data, and the read data is converted into a signal. A modulator 24 modulates data converted by the I / O control circuit and outputs the data to the outside of the IC card through the transmission antenna 23.

According to the configuration of FIG. 3 described above, the output current is amplified by the driver 9, the magnetic field generated from the transmitting antenna is increased, and the communicable area is expanded. In that case, a magnetic field is generated in the air, and the electromagnetic induction causes IC
An operating power supply and modulation data are supplied to the card 18. Conversely, data transmitted from the IC card 18 is received by the receiving antenna 14 of the reader / writer 1, external noise is removed by the filter 13, and is amplified by the demodulator 12 to demodulate the received data. The communicable areas are shown in FIG.
Here, a card receiving area, which is a communicable area when transmitting from the reader / writer to the IC card, and a card return signal demodulating area, which is a communicable area when returning from the IC card to the reader / writer, are shown. FIG.
The card return signal demodulatable area inside is a communication area where stable transmission and reception are possible.

[0007]

However, in the above conventional example, since the element constant in the driver 9 is fixed so as to expand the communicable area as much as possible, there is a difference in performance evaluation near the antenna. Hateful. In order to perform the performance evaluation more clearly, it is better to perform the evaluation in a closer environment when actually using it. One method is to perform performance evaluation at the boundary where the operation changes from a stable state to an unstable state, but in a system with a long communication distance,
The distance to the boundary line becomes long, and it is difficult to perform evaluation in a measurement environment with a limited area. Further, since the intensity of the electromagnetic wave generated by the IC card reader / writer is constant, it may unexpectedly affect other electronic devices in the vicinity. Further, since both the reception level and the transmission level cannot be adjusted, the reader / writer and the IC
The correlation between the communication radio wave intensity with the card becomes constant, and in some cases, the balance between transmission and reception may not be optimal. The present invention has been made in view of such circumstances, and its performance evaluation is possible in an environment of a limited area.
An object of the present invention is to provide a reader / writer for a C card.

[0008]

According to the first aspect of the present invention,
In a reader / writer that wirelessly communicates with a non-contact IC card, the non-contact IC card includes a means for adjusting a level of a communication radio wave for transmitting and receiving a signal to the non-contact IC card and power for driving the non-contact IC card. It is an IC card reader / writer. According to a second aspect of the present invention, in the non-contact IC card reader / writer according to the first aspect, the adjusting means includes a transmission level adjusting means for adjusting a transmission level. According to a third aspect of the present invention, in the reader / writer for a contactless IC card according to the first aspect, the adjusting means includes a receiving level adjusting means for adjusting a receiving level. According to a fourth aspect of the present invention, in the reader / writer for a contactless IC card according to the first aspect, the adjusting means includes a transmission level adjusting means for adjusting a transmission level and a receiving level adjusting means for adjusting a receiving level. It is characterized by doing. According to a fifth aspect of the present invention, in the reader / writer for a non-contact IC card according to the first aspect, a performance evaluation test of the non-contact IC card can be performed by the adjusting means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an IC card system according to one embodiment of the present invention will be described with reference to the drawings. FIG.
Shows the configuration of the reader / writer and the IC card according to the embodiment. In this figure, reference numerals 1 to 14 and reference numerals 18 to 27 are the same as those described in the section of the prior art, respectively. Reference numeral 15 denotes a transmission level adjuster, which specifically controls the driver 9 to amplify the output current. In this case, the output current value is amplified until the output electromagnetic wave reaches a legal limit value. Therefore, by adjusting the amplification factor of the amplification, the level of the output electromagnetic wave is suppressed, and the apparent state is the same as when the distance is increased. The transmission level adjuster 15 is inserted between the driver 9 and the resonance capacitor 10 to adjust the level of the output current of the reader / writer 1. Reference numeral 16 denotes a reception level adjuster that adjusts the level of a signal received by the reception antenna 14 or the level of an amplifier that amplifies the output of the filter 13 for extracting a frequency component of the signal. Since the signal returned from the IC card is weak, amplification is performed before and after the filter 13. By adjusting the amplification factor at that time, the reception level is adjusted so that the reception level is the same as the apparently distant state. The reception level adjuster 16 is inserted between the reception antenna 14 and the filter 13 to adjust the level of a reception signal from the IC card.

Since the IC card 18 has no power supply, its operation is performed by the power supplied from the reader / writer 1. The power supply method will be described below. I
It is assumed that the user holding the C card 18 stands in front of the reader / writer 1 and holds the IC card 18 over the reader / writer 1. Resonance capacitor 10 in reader / writer 1
An AC signal constantly transmitted from the reader / writer 1 is received by the reception antenna 19 in the IC card by a series resonance circuit including the transmission antenna 11 including a coil. This AC signal is rectified by the power supply 20,
The IC card 18 operates with this power.

Next, the operation of the IC card system will be described. First, a read command is issued from the reader / writer 1 to the IC card 18, and is demodulated by the demodulator 22 via the receiving antenna 19 in the IC card 18. Then, according to the content of the read command, Necessary information stored in the memory 26 is read by the I / O control circuit 25. This information is transmitted by the modulator 24 to the reader / writer 1 through the transmission antenna 23.
The reader / writer 1 receives the information sent from the IC card 18 via the receiving antenna 14, converts the information to an appropriate level by the reception level adjuster 16, and removes unnecessary frequency components by the filter 13. Demodulation is performed in the demodulator 12. Thereafter, this information is transmitted to the communication I / F circuit 6.
Is sent to the CPU 2. CPU2 is ROM
While accessing the 3 and the RAM 4, it is determined whether or not this information sent from the IC card 18 is correct, and the next processing is determined. In accordance with this processing, when output is required for the IC card, the following processing is subsequently performed.

When transmitting data or instructions to the IC card 18, the CPU 2
4. The host computer 27 is accessed via the communication I / F circuit 5 as needed, and data or instructions to be sent are prepared. This data or instruction
In the modulator 8 through the communication I / F circuit 6, the transmitter 7
After modulating the synchronization signal supplied from the
Amplified by Thereafter, the signal is converted to an appropriate level by the transmission level adjuster 15, and then the IC is turned on by a series resonance circuit including the resonance capacitor 10 and the coil 11.
Sent to card 18.

In the above operation, in the present embodiment, since the transmission level adjuster 15 is provided for transmission in the reader / writer 1, the output current flowing to the transmission antenna of the reader / writer 1 can be adjusted. Therefore, the intensity of the magnetic field generated from the transmitting antenna can be adjusted. Similarly, since the reception level adjuster 16 is provided in the reader / writer 1 for reception, the level of the signal received by the reception antenna can be adjusted.
The reception range of the reader / writer 1 device can be adjusted.

[0014]

As described above, according to the present invention,
According to the C-card reader / writer, the following effects can be obtained. 1. By providing the transmission level adjuster and the reception level adjuster inside the reader / writer, when there is another electronic device around the reader / writer for the IC card, it is possible to suppress the influence of the emitted electromagnetic wave on the electronic device. it can. 2. Similarly, since the transmission level and the reception level can be adjusted, the correlation between the transmission level and the reception level for the card can be adjusted, and a more stable communication state can be created. 3. Since the magnetic field generated from the transmitting antenna can be adjusted by providing the transmission level adjuster, if the adjustment is performed so as to weaken the magnetic field, it is equivalent to a distant position in an actual use environment within a limited space. Can be evaluated. 4. By providing the above-mentioned reception level adjuster, the signal level received by the reception antenna can be adjusted. Therefore, if the signal level is adjusted in the limiting direction, the IC card can be equivalently set to a position distant from the reader / writer. This makes it possible to evaluate the performance of the IC card and the demodulation capability of the reader / writer in a limited space.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the inside of a non-contact IC card reader / writer according to an embodiment of the present invention.

FIG. 2 is a diagram showing a communicable area of an antenna used in a reader / writer for a contactless IC card according to an embodiment of the present invention.

FIG. 3 is a block diagram showing the inside of a conventional reader / writer for a non-contact IC card.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reader / writer 2 ... CPU 3 ... ROM 4 ... RAM 5,6 ... Communication I / F circuit 7 ... Oscillator (OSC) 8,24 ... Modulator 12,22 ... Demodulator 9 ... Driver 10 ... Resonant capacitor 11 ... Coil 13 ... Filter 14, 19 ... Reception antenna 23 ... Transmission antenna 20 ... Power supply 21 ... Clock generator 25 ... I / O control circuit 26 ... Memory

Claims (5)

[Claims] 1. A non-contact IC card reader / writer for communicating wirelessly with a non-contact IC card, comprising: a signal for the non-contact IC card;
A reader / writer for a non-contact IC card comprising means for adjusting the level of a communication radio wave for transmitting and receiving power for driving a card. 2. The reader / writer for a contactless IC card according to claim 1, wherein said adjusting means includes a transmission level adjusting means for adjusting a transmission level. 3. The reader / writer for a contactless IC card according to claim 1, wherein said adjusting means comprises a receiving level adjusting means for adjusting a receiving level. 4. The reader / writer for a contactless IC card according to claim 1, wherein said adjusting means includes a transmission level adjusting means for adjusting a transmission level, and a receiving level adjusting means for adjusting a receiving level. 5. The reader / writer for a contactless IC card according to claim 1, wherein a performance evaluation test of the contactless IC card can be performed by the adjusting means.