JP2000259787A - Power supply method of non-contact ic card and non- contact ic card reader/writer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply an appropriate operation power to a non-contact IC card. SOLUTION: In the non-contact IC card reader/writer 10, an AC power outputted from a signal source 11 to a coil 14 is supplied to a non-contact IC card 20 through a coil 21 which is inductively coupled to the coil 14. An output voltage switch circuit 12 changing the AC power outputted from the signal source 11 to the coil 14 in multiple stages in accordance with the combination of plural control signals A and B from a microcomputer 15 and a control program 16a which is stored in a memory 16 and allows the microcomputer to execute a control action to gradually increase the AC power supplied to the non-contact IC card 20 through the coil 14 from the signal source 11 while monitoring the presence or absence of an initial response from the non-contact IC card 20, to fix the AC power to a minimum value with which a normal initial response is obtained are installed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact IC card power supply technology and a non-contact IC card reader / writer, and more particularly, to an IC card system using various non-contact IC cards having different power consumption and the like. To apply to effective technology.

[0002]

2. Description of the Related Art For example, a non-contact IC card does not have a contact point with a reader / writer, so that there are few contact failures and failures due to dirt and abrasion, so that maintenance costs can be greatly reduced. There are various advantages over contact-type IC cards, such as being printable without impairing the merchantability of the card, and being easy to use with no restrictions on the insertion direction and front and back when used, and their use is expanding.

A non-contact IC card reader / writer and a non-contact IC card which does not have a built-in power supply both have a built-in coil. It is conceivable to supply power to the The non-contact IC card generates a DC voltage by a power supply circuit from an AC voltage generated by inductive coupling, and operates an internal circuit (a communication circuit, a CPU, a memory, and the like).

However, when a non-contact IC card reader / writer communicates with a non-contact IC card, the distance is not constant. For this reason, even if the output of the non-contact IC card reader / writer is constant, the power transmitted to the non-contact IC card is not constant, and the power transmitted decreases as the distance increases.

For this reason, the output power of the conventional non-contact IC card reader / writer has been fixed to the output power necessary to satisfy the maximum communication distance at the assumed maximum power consumption of the non-contact IC card.

[0006]

In the prior art described above, when the contactless IC card is shorter than the maximum communication distance or when the contactless IC card is reduced in power consumption in the future, extra power is consumed. Is supplied to the non-contact IC card.

This is a waste of operating power on the side of the non-contact IC card reader / writer, and excess power is consumed as heat on the side of the non-contact IC card. This may cause heat generation, which may cause destruction of a constituent IC chip and decrease in life and reliability.

An object of the present invention is to provide a technique capable of realizing reduction of power consumption of a non-contact IC card reader / writer and reduction of heat generation of the non-contact IC card.

It is another object of the present invention to provide a technology capable of improving the life and operation reliability of a non-contact IC card.

Another object of the present invention is to provide a technique capable of using various contactless IC cards having different power consumption.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a non-contact IC card power supply method for supplying power from a non-contact IC card reader / writer to a non-contact IC card having no built-in power supply by inductive coupling. Monitoring the presence or absence of an initial response from the non-contact IC card while changing the power supplied from the IC card reader / writer to the non-contact IC card,
Non-contact IC with the set value of power when initial response was obtained
This is for operating the card.

Further, the present invention relates to a non-contact IC card reader / writer which performs data communication with a non-contact IC card by supplying power to the non-contact IC card having no power supply by inductive coupling. A power switching means for changing a set value of the power supplied to the contact IC card; and a power switching means for controlling the power switching means in accordance with the presence or absence of the initial response from the non-contact IC card, thereby changing the value of the power supplied to the non-contact IC card. And control means for determining.

More specifically, as an example, a non-contact IC
The card reader / writer has a built-in output voltage switching circuit that switches the voltage output to the inductive coupling coil, and a program that controls this circuit. When supplying power to the non-contact IC card, the output voltage is output from a low state. In order to fix the supplied power to the output when the contactless IC card performs the initial response operation.

Thus, the communication distance and individual non-contact IC
It is possible to supply a minimum and optimum amount of power according to the power consumption of the card.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a conceptual diagram showing an example of the configuration of an IC card system including a non-contact IC card reader / writer and a non-contact IC card for implementing a non-contact IC card power supply method according to an embodiment of the present invention. FIG.
FIG. 3 is a circuit diagram illustrating a part of the non-contact IC card reader / writer according to the embodiment taken out in more detail, and FIG. 3 is a diagram illustrating an example of the operation of the non-contact IC card reader / writer according to the embodiment. FIG. 4 is a flowchart illustrating an example of the operation of the non-contact IC card reader / writer according to the present embodiment.

FIG. 1 shows an example of a power supply portion in a non-contact IC card reader / writer 10 and a non-contact IC card 20 according to the present embodiment.

In the non-contact IC card reader / writer 10, a signal source 11 is a circuit for generating an AC signal which is a basic power supply.
a is output. The output voltage switching circuit 12 is the microcomputer 1
The voltage (VI) of the AC signal 11a from the signal source 11 can be switched by a control signal (control signal A, control signal B) from the control signal 5 and is output to the amplifier circuit 13 as an AC signal 11b of the voltage (VO). The amplification circuit 13 amplifies the AC signal 11b from the output voltage switching circuit 12 at a fixed magnification and outputs the amplified signal to the coil 14. The coil 14 is inductively coupled to the coil 21 of the non-contact IC card 20. The memory 16 stores a control program 16a for the non-contact IC card reader / writer 10, which realizes the function of the microcomputer 15 controlling the supplied power by a method described later.

On the other hand, the non-contact IC card 2 of the present embodiment
At 0, the coil 21 generates an AC voltage by being inductively coupled to the coil 14 of the non-contact IC card reader / writer 10. The power supply circuit 22 converts the AC voltage generated in the coil 21 to DC, and supplies power to an internal circuit 23 including a communication circuit (not shown), an MPU, a memory, and the like.

Here, an example of a data communication method between the non-contact IC card reader / writer 10 and the non-contact IC card 20 according to the present embodiment will be described.

The amplifier circuit 13 of the non-contact IC card reader / writer 10 transmits transmission data 15 a from the microcomputer 15.
The phase modulation circuit 13a and the phase modulation circuit 13 switch the phase of the AC signal output to the coil 14 to two types of phases corresponding to 0 and 1 according to the (binary signal of 0 and 1).
A transmission amplifier 13 which amplifies the output of a and gives it to the coil 14
b, a demodulation circuit 13c for demodulating the received data 15b from the load fluctuation of the coil 14 and supplying the demodulated data to the microcomputer 15.

On the side of the non-contact IC card 20, a load modulation circuit 24 connected in parallel to the coil 21 and varying the load of the coil 21 in accordance with the transmission data 23a output from the internal circuit 23; And a demodulation circuit 25 for detecting a phase change of an AC signal induced by the demodulation and demodulating the signal into a digital signal, and inputting it to the internal circuit 23 as received data 23b.

That is, data transmission from the non-contact IC card reader / writer 10 to the non-contact IC card 20 is performed by a phase corresponding to transmission data given to an AC signal output to the coil 14 on the side of the non-contact IC card reader / writer 10. Change
This is realized by detection by the demodulation circuit 25 on the non-contact IC card 20 side. The data transmission from the non-contact IC card 20 to the non-contact IC card reader / writer 10 is performed by changing the load of the coil 21 inductively coupled to the coil 14 for power supply in the load modulation circuit 24 according to the transmission data. Then, the load fluctuation is transferred to the non-contact IC card reader / writer 1.
This is realized by detection by the demodulation circuit 13c on the 0 side. Monitoring of the presence or absence of an initial response as described later is performed using the data communication function as described above.

FIG. 2 shows an example of the configuration of the output voltage switching circuit 12 when the control signal from the microcomputer 15 is A and B in the present embodiment. When the two control signals A and B supplied from the microcomputer 15 are both at the H level, the transistors 123 and 126 to which the control signals A and B are input via the resistors 124 and 127 are on. Therefore, the AC signal 11a (voltage VI) from the signal source 11 is connected to the resistor 121 (resistance value R0).
And a resistor 122 (resistance value R1) and a resistor 125 (resistance value R
The voltage (VO) divided by the combined resistance of 2) is output to the amplifier circuit 13 as an AC signal 11b.

Next, when the control signal A is at the H level and the control signal B is
Is low, the transistor 123 is on and the transistor 126 is off. Therefore, the AC signal 11a from the signal source 11 is output to the amplifier circuit 13 as an AC signal 11b of a voltage divided by the resistors 121 and 122. The value of the voltage (VO) is determined by the values of the resistors 121 and 122.

When control signal A is at L level and control signal B is at H level, transistor 123 is off and transistor 126 is on. Therefore, the AC signal 11a from the signal source 11 is converted into an AC signal 11b of a voltage (VO) divided by the resistor 121 and the resistor 125 and the amplifier circuit 13
Output to The value of the voltage (VO) is the resistance 121 and the resistance 1
It is determined by the value of 25.

Further, both the control signal A and the control signal B are L
When the level is the transistor 123, the transistor 126
Is off, and the AC signal 11a from the signal source 11 is output to the amplifier circuit 13 as the AC signal 11b as it is.

Therefore, the resistors 121, 122, 12
The output power of the amplifier circuit 13 shown in FIG. 1 can be sequentially increased to an arbitrary value by appropriately setting the magnitude relation between the resistance values R0, R1, and R2 of FIG.

FIG. 3 shows two control signals A, A as described above.
An example of the correspondence between the combination of the states of B and the value of the output voltage (VO) is shown. When both the control signals A and B are at the H level, the voltage VO output to the amplifier circuit 13 (coil 14) becomes minimum. When both the control signals A and B are at the L level, the voltage VO becomes maximum (= VI). ), And during this time, it is changed in a direction of increasing gradually.

The resistor 122, the transistor 123,
By increasing the number of circuit elements such as the transistor 126 and the resistor 125 and the number of control signals from the microcomputer 15,
More output voltages can be set, and more appropriate output power can be determined.

Hereinafter, an example of the power supply method of the non-contact IC card and the operation of the non-contact IC card reader / writer according to the present embodiment, that is, a control program stored in the memory 16 will be described with reference to the flowchart of FIG. An example of the operation of will be described.

As processing 141 before output switching, initialization of the non-contact IC card reader / writer 10 and non-contact IC
Processing for detecting the card 20 and the like are performed.

Next, the non-contact IC card reader / writer 10
Then, as the first power output control, the control signal A and the control signal B from the microcomputer 15 to the output voltage switching circuit 12 are both set to the H level in the process 142.

In this state, a process 143 for confirming the initial response from the non-contact IC card 20 is performed. This initial response means that the contactless IC card reader / writer 10 and the contactless IC
This is an initial response operation from the non-contact IC card 20 to the non-contact IC card reader / writer 10 in a predetermined data communication protocol defined with the card 20.

If there is an initial response, a non-contact IC
The processing moves to the next processing 150 for performing data communication with the card.

If there is no response in the process 143, the control signal is changed so that the output voltage becomes the next value. Here, a process 144 for setting the control signal A to the H level and the control signal B to the L level is performed.

In this state, a process 145 for confirming an initial response from the non-contact IC card 20 is performed.

In this process 145, if there is an initial response, the process proceeds to the next process 150 for performing data communication with the non-contact IC card.

If there is no response in the process 145, the control signal is changed so that the output voltage becomes the next value. Here, processing 146 for setting control signal A to L level and control signal B to H level is performed.

In this state, a process 147 for confirming an initial response from the non-contact IC card 20 is performed.

If there is a response in this process 147, the next process 150 for executing data communication with the non-contact IC card 20 is performed.
Move on to

If there is no response in the process 147, a process 148 for setting both the control signal A and the control signal B to L level and setting the voltage (VO) of the AC signal 11b to the maximum (= VI) is performed. Thereafter, a process 149 for acquiring an initial response from the non-contact IC card 20 is performed, and the process proceeds to the next process 150 for performing data communication with the non-contact IC card 20.

Although not particularly shown, if the initial response is not confirmed in the process 149, a predetermined error process is executed, and the data communication in the process 150 is not performed.

As described above, in the non-contact IC card reader / writer 10 of the present embodiment, as described above, the output voltage switching circuit 12 outputs the AC signal output to the amplifier circuit 13 (coil 14). 11b voltage (VO)
Contactless IC while increasing step by step from the lowest value
The presence or absence of an initial response from the card 20 is monitored, and when the initial response is obtained, that is, when the minimum power value required for proper operation of the non-contact IC card 20 is reached, the non-contact IC The value of the power supplied to the card 20 is fixed to the minimum power value, and the contactless IC card 2 is
Data communication can be started with 0.

For this reason, for example, the size of the communication distance between the non-contact IC card reader / writer 10 and the non-contact IC card 20 and a plurality of various non-contact I / Os having different power consumptions.
Optimal power supply suitable for the C card 20 can be realized.

As a result, the power consumption of the non-contact IC card reader / writer 10 can be reduced, and the heat generation of the non-contact IC card 20 due to excessive power supply can be reduced. Can be avoided, and the life can be extended and the reliability can be improved.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above-described embodiments and can be variously modified without departing from the gist thereof. Needless to say, there is.

[0048]

According to the power supply method for a non-contact IC card of the present invention, it is possible to reduce power consumption of a non-contact IC card reader / writer and to reduce heat generation of the non-contact IC card. .

According to the method for supplying power to a non-contact IC card of the present invention, the effect that the life and reliability of operation of the non-contact IC card can be improved can be obtained.

According to the power supply method for a non-contact IC card of the present invention, it is possible to use various non-contact IC cards having different power consumption.

Further, according to the non-contact IC card reader / writer of the present invention, it is possible to reduce the power consumption of the non-contact IC card reader / writer and to reduce the heat generated by the non-contact IC card.

According to the non-contact IC card reader / writer of the present invention, it is possible to improve the life and operation reliability of the non-contact IC card.

According to the non-contact IC card reader / writer of the present invention, it is possible to use various non-contact IC cards having different power consumption.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of a configuration of an IC card system including a non-contact IC card reader / writer and a non-contact IC card for implementing a non-contact IC card power supply method according to an embodiment of the present invention. .

FIG. 2 is a circuit diagram illustrating a part of a non-contact IC card reader / writer according to an embodiment of the present invention in more detail;

FIG. 3 is a diagram showing an example of the operation of a non-contact IC card reader / writer according to an embodiment of the present invention.

FIG. 4 is a flowchart illustrating an example of an operation of a non-contact IC card reader / writer according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Non-contact IC card reader / writer 11 Signal source 11a AC signal 11b AC signal 12 Output voltage switching circuit (power switching means) 13 Amplifying circuit 13a Phase modulation circuit 13b Transmission amplifier 13c Demodulation circuit 14 Coil 15 Microcomputer (Control means) 15a Transmission data 15b Received data 16 Memory 16a Control program (control logic) 20 Non-contact IC card 21 Coil 22 Power supply circuit 23 Internal circuit 23a Transmission data 23b Received data 24 Load modulation circuit 25 Demodulation circuit 121 Resistance 122 Resistance 123 Transistor 124 Resistance 125 Resistance 126 Transistor 127 Resistance A, B Control signal

Claims (4)

[Claims] 1. A non-contact IC card power supply method for supplying power by inductive coupling from a non-contact IC card reader / writer to a non-contact IC card having no built-in power supply, the method comprising: The non-contact IC
The contactless I while changing the power supplied to the card.
The presence or absence of the initial response from the C card is monitored, and the non-contact IC is set based on the set value of the power at the time when the initial response is obtained.
A power supply method for a non-contact IC card, which comprises operating the card. 2. The non-contact IC card according to claim 1, wherein the power supplied from the non-contact IC card reader / writer to the non-contact IC card is increased stepwise. Monitoring the presence or absence of an initial response from the non-contact IC card, and operating the non-contact IC card at the set value of the power at the time when the initial response is obtained. 3. The non-contact IC card which does not have a built-in power supply is supplied with electric power by inductive coupling, so that
What is claimed is: 1. A non-contact IC card reader / writer for performing data communication with a C card, comprising: a power switching unit for changing a value of the power supplied to the non-contact IC card; A non-contact IC card reader / writer, comprising: control means for determining the set value of the power to be supplied to the non-contact IC card by controlling the power switching means according to the presence or absence. 4. The non-contact IC card reader / writer according to claim 3, wherein the control means controls the power switching means to increase the value of the power supplied to the non-contact IC card in a stepwise manner. And control logic for performing the data communication with the non-contact IC card while operating the non-contact IC card at the set value of the power when the initial response is obtained from the non-contact IC card. A non-contact IC card reader / writer.