JP2001067446A - Non-contact ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make securely transmittable information, when power supply from a terminal falls short or breaks off, by providing an auxiliary power source of a small capacity. SOLUTION: In an antenna circuit (resonance circuit) 60, data are transmitted and received, and power supply is performed by an electromagnetic wave 70 from a terminal (reader/writer). Supplied power is fed to a power switching circuit 40 through a voltage stabilization circuit 31 and then fed to IC 10. A diode 41 is connected to the output of the voltage stabilization circuit 31 so that power can be supplied to the power switching circuit 40 from an auxiliary power source 20. When power supply from the electromagnetic wage 70 falls short or breaks off, power is supplied from the auxiliary power source 20. The auxiliary power source 20 is of small capacity but it functions so that a processing can be completed even if the card is situated at the location farther than a transmission possible distance during the processing with the terminal or to store in memory that the system operation is terminated in the middle of processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in fields such as access control systems, traffic ticket gate systems, and the like.
Non-contact type I that sends and receives data using electromagnetic waves as a communication medium
It concerns the C card.

[0002]

2. Description of the Related Art Conventionally, a non-contact type IC card has a built-in battery having a power source such as a battery, and a non-contact type IC card which does not have a power source such as a battery at all and supplies power by electromagnetic coupling of electromagnetic waves from the outside. There is a battery-less type to receive. An IC card with a built-in battery always uses its power supply during transmission processing with a terminal device, and may cause significant battery consumption due to malfunction due to noise or the like. Furthermore, card thickness 0.8m
It is difficult for a non-contact type IC card of about m to have a battery replaceable structure.
The C card had to be discarded, and there was a problem with economy.

Further, it is necessary to increase the battery capacity in order to always use the power source. For this reason, it is necessary to increase the volume occupied by the battery, and not only the physical strength of the IC card itself becomes a problem, but also when adding other functions (for example, photograph, magnetic stripe, embossing, etc.) to the IC card. In addition, there is a problem that unevenness is generated on the card surface due to the shape of the built-in battery, and the smoothness is impaired.

Further, in a batteryless non-contact type IC card having no battery, power can be received from a terminal (reader / writer) and processing can be continued only during transmission processing with the terminal (reader / writer). . However, if the distance deviates from the power-receivable distance, the processing is interrupted, so that normal use cannot be performed at the next use, and depending on the state of the data writing process, damage that cannot be restored to the stored data may be caused. .

Conventionally, in order to prevent this kind of failure, a status that writing has been completed without processing has been set in the nonvolatile memory immediately before the writing process, and then the status is set again.
The writing process starts. When the writing is completely completed, a method has been adopted in which the status is cleared to indicate that the correct writing has been performed. Also, if the power supply from the terminal (reader / writer) is interrupted on the way and the processing such as writing is not completed,
Depending on the status of the non-volatile memory indicating this,
Complementing this, processing on the system application side was to be performed. For example, it is an instruction to instruct the card holder to repeat the same operation again.

In a non-contact type IC card system,
There is usually a certain distance between the card and the terminal (reader / writer), and the passage time and transmission distance of the terminal differ depending on the IC card holder. One of the causes of the above-mentioned processing such as writing being unprocessed is that continuation of processing becomes difficult because sufficient power is not supplied to the non-contact type IC card. Therefore, even if the creator of the IC card system predicts a sufficient processing time and designs the system, depending on the behavior of the IC card holder, unexpected situations such as redo of transmission, redo of verification, authentication processing, and the like may occur. May occur. In such a case, in the related art, as described above, the status of being unprocessed remains in the non-volatile memory of the non-contact type IC card as a status. Was instructed to do so. Strictly speaking, in the conventional system, a terminal (reader / writer) transmits a non-contact type IC.
Since it is unknown when the power to the card will be turned off, it may not be possible to leave a status of unprocessed in the worst case. In this case, no memory remains on the card side, and the subsequent processing may be difficult.

[0007]

SUMMARY OF THE INVENTION The present invention provides a non-contact type
It is an object of the present invention to provide a non-contact type IC card capable of reliably transmitting information even when power supply from a terminal (reader / writer) of a C card is weak or interrupted.

[0008]

Means for Solving the Problems According to the first aspect of the present invention, which has been made to solve the above-mentioned problems, the non-contact IC card is longer than a transmittable distance during processing with a terminal (reader / writer). Even if you leave, the process is completed or
Alternatively, there is provided a non-contact type IC card having a small-capacity auxiliary power supply which can at least store a time during which a process can be stored.

Further, according to the present invention, the power supply is switched from the auxiliary power supply so that the processing can be continued without any problem even if the power supply from the terminal (reader / writer) is momentarily cut off during the processing. A non-contact IC card to which power is supplied through a circuit.

The invention according to claim 3 is a small-capacity power supply element such as a solar cell, a large-capacity capacitor, or a paper battery as the auxiliary power supply, wherein the auxiliary power supply is incorporated. Item 1. Non-contact type I according to item 1 or 2.
It is a C card.

Further, the invention according to claim 4 is characterized in that when the IC card is inserted into the card holder, the power can be charged by bringing the charging terminal of the card holder having a battery into contact with the charging terminal of the auxiliary power supply. Claim 1,
2. The contactless IC card according to item 2. The above function can be performed by charging the IC card when it is not used.

Further, according to a fifth aspect of the present invention, in the non-contact type IC card according to the first or second aspect, the auxiliary power supply is a solar cell, and the auxiliary power supply is charged by irradiating light. It is.

According to a sixth aspect of the present invention, the non-contact power supply comprises a bridge circuit of a diode element and a capacitor, and the auxiliary power supply is charged by electromagnetic waves. Type IC card.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a non-contact type IC card of the present invention. This configuration is similar to that of a normal non-contact type IC card except that it has an auxiliary power supply and a power supply switching circuit.

That is, the IC (10) includes a CPU (14) for performing data processing according to a user's program, a ROM (16) for storing a program, a RAM (17) for storing data, and a clock for operating. (1
5), a bus (1) for transmitting data and addresses, etc.
3) a modulation / demodulation circuit (11) for modulating / demodulating from analog to digital and from digital to analog;
1) and an input / output control circuit (12) for performing parallel / serial conversion of data between the bus (13).

In supplying power to the IC (10), power from an auxiliary power supply and power obtained from electromagnetic waves are connected to a power supply switching circuit so that the power supply can be switched. When switching the power supply, the diodes (41, 42) and the resistor (4
Forming a power supply switching circuit (40) composed of 3)

The antenna circuit (resonant circuit) (60) is composed of a coil (61) and a variable capacitor (62), and is used for transmitting / receiving data and supplying electricity from a terminal (reader / writer) by an electromagnetic wave (70). A bridge circuit (50) comprising diodes (51, 52, 53, 54) for rectifying an AC voltage obtained from a received electromagnetic wave into a DC voltage, and a circuit for stabilizing the obtained power. 2 and connected to a power supply switching circuit (40) through a power supply stabilizing circuit (31).

On the other hand, a diode (4) is provided so that power can be supplied from the auxiliary power supply (20) to the power supply switching circuit (40).
1) is connected to the output of the voltage stabilizing circuit (31). When the power supply from the electromagnetic wave is reduced or interrupted, power is supplied from the auxiliary power supply. With such a configuration, the modulation / demodulation circuit (11), the CPU
(14) It is possible to supply power to the storage elements (16, 17) and the like, so that information can be transmitted reliably.

As a small-capacity power supply element, a thin conductive film and an insulating film are stacked in multiple layers by using thin solar cells and paper batteries used in calculators and the like, or the current semiconductor technology and thin film forming technology. A comparatively large electric capacitance to be manufactured and a thin capacitor can be used. Further, when forming the card base material of the non-contact ID card, a capacitor, a battery and the like may be formed by the same thin film technology.

As a method of charging the auxiliary power supply, a resistor (43) of the power supply switching circuit is connected to the output of the voltage stabilization circuit (31), and the power is charged with surplus power through a diode (42) connected in series with the resistor. I do. When the card is inserted into the card holder as shown in FIG. 3, the charging terminal of the auxiliary power supply and the charging terminal of the card holder are connected to transfer the power of the card holder to the auxiliary power supply. In addition, the power of the auxiliary power supply can always be maintained at a constant level.

Further, a conventionally known solar cell may be irradiated with light, and an auxiliary power supply may be charged by an electromagnetic wave by an antenna circuit.

[0022]

As described above, by providing the auxiliary power supply in the non-contact type IC card, even if the supply of power from the terminal (reader / writer) is reduced or interrupted,
Processing can be performed reliably.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a non-contact type IC card of the present invention.

FIG. 2 is a voltage stabilization circuit diagram.

FIG. 3 is a diagram illustrating a method for charging an auxiliary power supply in a non-contact type IC card by a card holder.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... IC 11 ... Modulation / demodulation circuit 12 ... I / O control circuit 13 ... Bus 14 ... CPU 15 ... Clock 16 ... ROM 17 ... RAM 20 ... Auxiliary power supply 21 ... External charging terminal 30 ... Storage capacitor 31 ... Voltage stabilization circuit 40 ... Power supply Switching circuits 41, 42 Diode 43 Diode 50 Bridge circuits 51, 52, 5
3, 54: Diode 60: Antenna (resonant circuit) 61: Coil 62: Variable capacitor 70: Electromagnetic wave 80: Non-contact IC card 81: Charging terminal 90: Card holder 91: Charging terminal

Claims (6)

[Claims] 1. Even if a non-contact IC card is separated from a terminal (reader / writer) by a distance longer than a transmittable distance during a process with a terminal (reader / writer), the process is completed or at least during the process. A non-contact type IC card having a small-capacity auxiliary power supply for covering a time for enabling storage. 2. Even if power supply from a terminal (reader / writer) is momentarily cut off during processing, power is supplied from an auxiliary power supply through a power supply switching circuit so that processing can be continued without any problem. Characteristic non-contact type IC card. 3. The non-contact type IC according to claim 1, wherein the auxiliary power supply is a small-capacity power supply element such as a solar cell, a capacitor, and a paper battery, and the auxiliary power supply is built-in. card. 4. The power charging device according to claim 1, wherein when the IC card is inserted into the card holder, the charging terminal of the card holder having the battery is brought into contact with the charging terminal of the auxiliary power supply to charge the power. Non-contact type IC card. 5. The non-contact type IC card according to claim 1, wherein the auxiliary power source is a solar cell, and the auxiliary power source is charged by irradiating light. 6. The non-contact type IC card according to claim 1, wherein the auxiliary power supply comprises a bridge circuit of a diode element and a capacitor, and is charged with an electromagnetic wave.