JP2000090221A - Non-contact ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable stable operation based on power supply due to electromagnetic induction by switching the operation of an IC card and the charging of a secondary battery with excess power, and the operation of an IC module with the secondary battery corresponding to the voltage of supplied power. SOLUTION: When an IC module 105 is turned into active state, a voltage is induced between the terminals of an antenna coil 102, rectified by a rectifier circuit 204b and made into power of a prescribed voltage. By periodically executing a voltage monitoring program 213a through a CPU 210, the voltage of power rectified by the rectifier circuit 204b is compared with an IC card driving enable voltage value. When the rectified voltage value is higher than the IC card driving enable voltage, power is supplied from the antenna coil 102 through a regulator 204c to an IC card controller and when the voltage value is further higher than a specified voltage, charging processing is simultaneously performed. When the voltage value is lower than the IC card driving enable voltage, a supply power switching circuit 204e is controlled and processing is switched to power supply from a secondary battery 104 through a charging/discharging control circuit 203.

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, and more particularly, to a non-contact IC card capable of performing stable operation in power supply by electromagnetic induction via radio waves.

[0002]

2. Description of the Related Art In recent years, IC cards equipped with an IC module are rapidly spreading because they can realize much higher security than magnetic cards. In particular, recently, an electronic money system using an IC card has attracted attention, and an ATM terminal device (hereinafter, an ATM terminal) has been attracting attention.
Since ICs can be made cashless, IC cards are expected to be widely used because there is no need to transfer cash, which is a problem in security of conventional ATM terminals. The most popular IC card is IC
Although a contact type IC card in which a module is exposed as a contact, a non-contact type IC card using data transmission by electromagnetic induction or the like via a radio wave is gradually spreading.
Since the IC module is not exposed, the non-contact type IC card has an advantage of operating while maintaining high reliability even in an environment with a lot of dust.

In recent years, this non-contact type (contactless) I
Standardization of C-cards is underway, and proposals have been made for a close-contact type (up to 2 mm), a close-up type (from about 2 mm to about 10 mm), and a close-up type (about 10 mm to 70 cm). In this method, an IC card reader and an IC card are coupled by, for example, a radio wave having a center frequency of 13.56 MHz to supply power and transmit and receive data. The specific concept is a problem to be solved. is there. As a power supply to such an IC card, an I-type battery with a rechargeable secondary battery is mounted.
C cards have already been proposed. See, for example,
Japanese Patent Publication No. 166019 discloses an IC card in which a sheet-shaped polymer secondary battery is disposed on at least one card surface of an IC card main body. Japanese Patent Application Laid-Open No. 9-326021 discloses a non-contact interface device and a transmitting / receiving coil for exchanging data with a terminal device in a non-contact manner. There is disclosed a composite IC card including a data processing device for processing the received data, a rechargeable battery, and a charging device for charging the battery with power supplied from a terminal device by contact.

[0004]

By the way, the above-mentioned prior art relating to power supply to an IC card is not sufficient from the viewpoint of power supply in consideration of a non-contact type IC card which receives power from the outside. Not really.
The reason is that the non-contact type IC card does not always receive stable power because it receives power supply through a medium called radio waves. For example, Japanese Patent Application Laid-Open No.
Japanese Patent Publication No. 166019 does not describe a non-contact type IC card, and is an excellent technology in terms of power supply to a general IC card. The issue of power supply due to electromagnetic induction has not been addressed. Further, the above-mentioned Japanese Patent Application Laid-Open No. 9-3
Japanese Patent No. 26021 discloses a technique for a composite IC card that enables data exchange in two modes, a contact type and a non-contact type. However, when power is not supplied by electromagnetic induction, power supplied from a paper battery is used. It has a configuration. Therefore, it is necessary to adopt a form in which the contact terminals are exposed on the card surface. As a result, the advantage of the non-contact type IC card is sacrificed. That is, the non-contact type IC card can maintain high reliability even in a dusty environment, and has high durability against insertion and removal. SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem of the related art, and to provide a non-contact type IC card capable of performing a stable operation in power supply by electromagnetic induction via radio waves. is there.

[0005]

To achieve the above object, a non-contact type IC card according to the present invention has a structure in which electric power obtained by radio waves supplied via an antenna coil is a voltage which can be operated as an IC card. Detection means for detecting whether or not the voltage is equal to or more than a value, a charging circuit for charging the secondary battery or the capacitor, and when the supplied power is less than the operable voltage value according to the detection result of the detection means, The IC card is operated by the power, and when the supplied power is equal to or higher than the operable voltage value,
Switching means for operating the C card and charging the secondary battery or the capacitor with the surplus power by the charging circuit.

[0006]

As described above, the voltage value of the electric power received by the antenna coil by the radio wave is monitored, and when the voltage of the supplied power is less than the operable voltage value in the power supply by the radio wave, the secondary battery or the condensate is used. Power of I
The C card is operated, and when the voltage of the supplied power is equal to or higher than the movable voltage value, the secondary battery or the capacitor is charged via the charging circuit with the surplus power during or after the operation. As a result, when the voltage is less than the operable voltage value in the unstable power supply by the radio wave, the IC module is operated using the stable power of the battery or the capacitor without using the unstable power by the radio wave, and Since power is used for charging, power is not wasted. Moreover, even when the power received by the antenna coil by radio waves is used, excess power can be transferred to the charging side, so that even if the radio wave output is too strong, the IC module side can use stable voltage power. . In addition, the power for charging can be charged even when receiving somewhat unstable power, or during operation,
It is charged by receiving power supply according to strong radio waves. When the voltage of the surplus power is low, a booster circuit may be provided for charging. Further, when power from a secondary battery or a capacitor is used, when the voltage is reduced, a transmitting means for transmitting a power supply request signal to a power supply side by radio waves is provided. For example, this makes it possible to charge these secondary batteries or capacitors.

In the above case, a flexible secondary battery can be used as the battery. In such a case, by taking a form in which the flexible secondary battery is not exposed on any of the card surfaces, high reliability can be maintained even in a dusty environment. As a flexible secondary battery, a polymer lithium secondary battery can supply a voltage of 3 V or more, and thus is preferable for power supply for driving an IC module. In addition, in order to prevent overcharging when charging the flexible secondary battery, it is preferable to include means for monitoring the charging current of the flexible secondary battery, and the current has become equal to or less than a predetermined current value. It is sometimes preferable to terminate charging. Further, it is preferable to provide a means for monitoring the charging time, and terminate the charging when the specified charging time is reached. By these,
Fire or smoke caused by overcharging can be prevented. Further, in order to prevent overdischarge of the flexible secondary battery, it is preferable that a means for monitoring a discharge voltage is provided, and the discharge is stopped when the discharge voltage falls below a specified discharge voltage. Further, a means for monitoring the discharge current may be provided, and the discharge may be stopped when the discharge current exceeds a specified discharge current. In this way, even if a short circuit or the like occurs, an excessive current can be prevented from flowing from the battery.

By the way, the secondary battery is preferably arranged inside the closed curve of the antenna coil, and this makes it possible to take a large mounting volume of the secondary battery, which is advantageous in terms of the capacity of the secondary battery. . Furthermore, it is also possible to increase the area surrounded by the closed curve of the antenna coil, which is advantageous in terms of power supply transmitted by electromagnetic induction. In addition, if the secondary battery and the magnetic material having a magnetic permeability equal to or higher than the vacuum magnetic permeability are located inside the closed curve of the antenna coil, the magnetic flux density crossing the closed curve of the magnetic coil can be increased, and the electromagnetic field can be increased. The power supply transmitted by induction can be made more efficient. The magnetic material depends on the frequency band used for power transmission, but MnZn ferrite or NiZn ferrite is preferable. In particular, the frequency used in the proximity type or the proximity type is 13.56 M
In the case of Hz, NiZn ferrite is preferable.

[0009]

FIG. 1 is a block diagram of an embodiment to which the non-contact type IC card of the present invention is applied, and FIG. 2 is an exploded explanatory view of an example of the entire configuration. In FIG. 2, 1 is
It is a non-contact type IC card, and the non-contact type IC card 1
Top cover sheet 101, core sheet 103 having antenna coil 102, polymer lithium secondary battery 10
4, an IC module 105, and a lower cover sheet 106. The core sheet 103 is a sheet-like substrate for using the antenna coil 102 as a magnetic coupling coil. The core sheet 103 has an opening 108 or a concave portion 108 on the inside. The non-contact type IC card 1 has a flexible A secondary battery 104 (here, a polymer lithium secondary battery) was fitted into the opening 108 or the concave portion 108 of this sheet, and was sandwiched between at least one of the upper and lower portions by the insulating material of the upper cover sheet 101 or the lower cover sheet 106. It has a structure (see the cross-sectional view of FIG. 4C). A terminal 107 is connected to the end of the secondary battery 104.
c, 107d, and these terminals 107c, 10d
The IC module 105 is connected via 7d (see FIG. 1).

That is, the non-contact type IC card 1 includes a polymer lithium secondary battery 104 which is a flexible secondary battery, an antenna coil 102, and an IC module 1.
Here, as the power supply means in the IC module 105, at least one of the power supply from the polymer lithium secondary battery 104 (hereinafter referred to as the secondary battery 104) and the power supply from A configuration is adopted in which selection is made according to the supply amount (its voltage). A power supply circuit 204 described later is built in the IC module 105 as a selection circuit.

As shown in FIG. 1, the IC module 105 includes an IC card controller 201, a protection circuit 202 for the secondary battery 104, a charge / discharge control circuit 203, and a power supply circuit 204. IC card controller 20
1 is a CPU 210, a RAM 211, a ROM 212, an E
It has an EPROM 213 and an input / output control circuit 214, and these circuits are mutually connected via a bus 215. Further, a power supply circuit 204 is also connected to the bus 215, which is under the control of the CPU 210. The input / output control circuit 214 is a circuit that receives data from the terminals 107a and 107b connected to the antenna coil 102 or sends signals to these terminals to control data transmission. The terminals 107a and 107b also serve as power supply terminals here, and are also connected to the power supply circuit 204 described above. Therefore, when the received radio wave is a modulated radio wave, it is extracted as a signal by the input / output control circuit 214, demodulated, and sent to a data processing circuit such as the CPU 210. In a non-modulation state where only the carrier wave (carrier) is transmitted or in a constant amplitude state, particularly in the case of a carrier wave with a strong power wave for power, it is received by the power supply circuit 204 as power, and the power supply circuit The electric power is extracted by the electric power 204. The modulation at the time of data transmission between the non-contact type IC card 1 and its reader (here, the IC card reader / writer 2) is usually one of ASK, PSK and FSK.

The power supply circuit 204 includes a tuning circuit 204
a, a rectifier circuit 204b, a regulator 204c, a voltage detection circuit 204 for detecting an output voltage of the rectifier circuit 204b
d, and a supply power switching circuit 204e that performs power supply switching processing according to the detection signal of the output voltage detection circuit 204d. Here, the supply power switching circuit 204e
Switches the supply power of the IC module 105 and the like to either the output of the regulator 204c or the output of the secondary battery 104 connected to the terminals 107c and 107d, and controls charging and discharging of the secondary battery 104. The starting circuit 205 to which a small amount of power is supplied from the secondary battery 104 is connected to the tuning circuit 204a. The starting circuit 205 operates the IC module 105 when a current signal based on a radio wave of a weak predetermined frequency is received via the antenna coil 102.
a high-frequency amplifier circuit for high-frequency amplification of the signal from a, a rectifier circuit, a power-on reset circuit that operates by receiving the output of the rectifier circuit, a power switch circuit, and the like. When you do
By activating the power switch circuit and activating the power-on reset circuit, the IC module 105 is activated and put into an operating state.

The supply power switching circuit 204e monitors the voltage of the power supplied from the rectifier circuit 204b to the regulator 204c from the antenna coil 102 via the terminals 107a and 107b by receiving the detection signal of the voltage detection circuit 204d. When the voltage of the rectifier circuit 204b detected by the output voltage detection circuit 204d is equal to or higher than 4.0 V, the regulated voltage, for example, 3.6 V, is transmitted from the regulator 204c to various internal circuits and the regulator is controlled. A part of the power supplied to the secondary battery 204c is supplied to the secondary battery 104 via the charge / discharge circuit 203 and the protection circuit 202 as a charging current. Alternatively, the capacitor 204f of the rectifier circuit 204e is charged with surplus power, and the surplus power is charged to the secondary battery 104 after the operation. In the latter case, since the capacity of the capacitor 204f is large, the capacitor 204f may be a capacitor externally attached to the IC.

The supply power switching circuit 204e is stabilized by the regulator 204c when the voltage of the rectifier circuit 204b detected by the output voltage detection circuit 204d is, for example, lower than 4.0V but higher than 3.6V. Voltage power is sent out by various internal circuits.
The charging of the secondary battery 104 via the charging / discharging circuit 203 and the protection circuit 202 is stopped, and the capacitor 204f of the rectifier circuit 204e is simply charged to secure the power. On the other hand, when the voltage of the power supplied from the rectifier circuit 204b to the regulator 204c via the terminals 107a and 107b is less than the above-mentioned 3.6 V, the supply power switching circuit 204e cuts off the output power from the regulator 204c. Power is supplied from the secondary battery 104 via the protection circuit 202 and the charge / discharge circuit 203 to supply power to various internal circuits.

Thus, even when the reception state of the radio wave is weak, that is, in the state of a so-called weak electric field, various internal circuits can operate stably. The above switching control of the supply power switching circuit 204e is performed by the CPU 210.
Is performed by a program to be executed. The voltage monitoring program 213a and the charge request processing program 21 for that
3b is stored in the EEPROM 213. The voltage monitoring program 213a executes the CPU by the periodic interrupt processing.
The current value of the rectifier circuit 204b, which is periodically executed by the power supply circuit 210 and detected by the output voltage detection circuit 204d via the power supply circuit 204, is obtained in the form of a digital value. The switching control is performed by transmitting a predetermined control signal. Note that the power supply circuit 204 has an A / D conversion circuit inside.

FIG. 3 is a flowchart of the charging and power supply operation of the non-contact type IC card. When the non-contact type IC card 1 is brought closer to an IC card reader or an IC card reader / writer 2 (see FIG. 1) compatible with the non-contact type IC card, the antenna coil 10 of the non-contact type IC card 1
2 receives an electromagnetic wave transmitted from a non-contact type IC card compatible reader (reader / writer) (step 10).
1). At this time, a weak radio wave of a predetermined frequency, for example, a radio wave of a frequency of 13.56 MHz is supplied to the antenna coil 102. When this is received by the antenna coil 102, the tuning is performed by the tuning circuit 204a, and when the received radio wave level reaches a certain level, the starting circuit 205 operates to start the IC module 105. With this IC
Module 105 enters the operating state. At the same time, a voltage is induced between the terminals of the antenna coil 102 by this reception, and the voltage is induced by the rectifier circuit 204b in the power supply circuit 204.
Received and rectified to power of a predetermined voltage (step 1).
02). The power supply circuit 204 has a CPU
The periodic execution of the voltage monitoring program 213a by the
And the voltage of the power rectified by the rectifier circuit 204b is compared with the IC card drivable voltage value (step 103).

Here, if the rectified voltage value of the power obtained through the antenna coil 102 is equal to or higher than the IC card drivable voltage (for example, the above-mentioned 3.6 V), the IC card controller sends a signal from the antenna coil 102 to the IC card controller. Power is supplied via the regulator 204c (step 104).
Further, as shown by the dotted line, the process proceeds to step 108,
When the voltage value is 4.0 V or more, the charging process is performed at the same time. At this time, the process is not terminated, and as shown by a dotted line, the process proceeds from step 108 to step 1 described later.
The process moves to 06. Conversely, if the voltage rectified from the antenna coil 102 is lower than the IC card driving voltage,
The CPU 210 controls the power supply switching circuit 204e to switch to power supply from the secondary battery 104 through the charge / discharge control circuit 203 (step 105). Further, as described later, when the power supply is switched to the power supply from the secondary battery 104, the CPU 120 monitors the battery voltage by executing the voltage monitoring program 213a, and the battery voltage becomes equal to or less than a predetermined value. For example, when the voltage drops to 3.3 V or less, the charge request signal 41
(See FIG. 5), and enters a charging request process for requesting the IC card reader side (radio wave transmitting side) to generate power supply radio waves.

In this manner, the power from the antenna coil 102 or the power from the secondary battery 104 is obtained, and
The C module 105 is started, and communication with the antenna coil 102 and signal processing are performed (step 106). When the data transmission process is completed, the CPU 210 controls the supply power switching circuit 204e to
The surplus power stored in the capacitor 204f is charged to the secondary battery 104 via the
8). In this case, when the surplus power is less than the charging voltage, a booster circuit or the like may be provided to boost and charge.

In FIG. 2, the upper cover sheet 101 and the lower cover sheet 106 can be made of any insulating material or a conductive material having an insulating property on the surface. It is preferable to use an insulating plastic sheet because it is excellent and can be manufactured at low cost. As the insulating plastic sheet, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, or the like can be used. Since the antenna coil 102 is a coil used for data transmission and power transmission using electromagnetic induction, for example, aluminum, copper,
A good conductive metal material such as silver, gold, tin, lead, indium, chromium, and nickel may be used. In the form in which the conductive wire is wound, a wire in which a good conductive metal material is covered with an insulator is preferable to avoid a short circuit. PET of good conductive metal foil
It is not always necessary to cover the insulator as long as it is attached and etched.

The core sheet 103 has an antenna coil 102 as shown in FIG.
08, and the terminals 107a and 107b are connected to the antenna coil 102. Core sheet 1
03 may be a mode in which the antenna coil 102 is sandwiched by PET or the like, but the pattern of the antenna coil 102 may be formed on polyethylene terephthalate or the like by, for example, aluminum, copper, silver, gold, tin, lead, indium, chromium, nickel, or the like. A form in which a foil of a conductive metal material or an alloy containing at least one or more of these metal materials is attached and etched can be employed. Alternatively, paste printing may be used. Further, on a substrate such as polyethylene terephthalate, a thin film of a highly conductive metal material such as aluminum, copper, silver, gold, tin, lead, indium, chromium, nickel, or an alloy containing at least one of these metal materials is provided. After forming by vacuum evaporation, sputtering, ion plating, etc., the thin film is subjected to precision etching, laser beam cutting, or the like, so that the pattern of the antenna coil 102 is formed as a thin film on polyethylene terephthalate or the like. Is also good.
As a preferable example of the production of the core sheet 103, the antenna coil 102 is produced by winding a copper wire whose periphery is covered with an insulator, and is thermocompression-bonded with two PET sheets together with an adhesive, and then the opening 108 is punched out. Thus, the core sheet 103 can be manufactured. The secondary battery 104 has a capacity of 3.6 when discharged.
Although it is a battery which can supply a voltage of V and is particularly preferable as a flexible secondary battery, another flexible secondary battery may be used instead.

As shown in FIG. 4B, the core sheet 10
The secondary battery 104 is fitted into the third opening 108. From the secondary battery 104, a copper wire 109a coated with an insulator,
109b is connected to the IC module 105 via terminals 107c and 107d. The antenna coil 102 is connected to the IC module 105 via terminals 107a and 107b. Thereby, the non-contact type I
In the C card 1, the area surrounded by the closed curve of the antenna coil 102 can be increased. This is advantageous in terms of power supply transmitted by electromagnetic induction. Further, as an example here, as shown in the cross-sectional view of FIG.
Between 06, a core sheet 103 having an antenna coil 102, a secondary battery 104, and an IC module 105 are sandwiched. Top cover sheet 10
The gap between the first and the lower cover sheet 106 is sealed with resin, and the secondary battery 104 is in a form that is not exposed on any of the card surfaces. As a result, a non-contact type IC card that can maintain high reliability even in an environment with a lot of dust can be realized.

FIG. 5 shows a power supply request transmission process (charge request process) by the voltage monitoring program 213a when the supply voltage falls below a predetermined value, for example, 3.3 V or less, in the power supply of the secondary battery 104. It is a flowchart of FIG. First, when a weak radio wave of a predetermined frequency, for example, a radio wave of 13.56 MHz is received by the antenna coil 102, tuning is performed by the tuning circuit 204a, and when the level of the received radio wave reaches a certain level, the starting circuit is activated. 20
5 operates and receives electric power from the secondary battery 104 to activate the IC module 105 and enter an operating state. When the IC module 105 enters an operation state, in an ordinary state, the IC module 105 in the non-contact type IC card 1 monitors the output voltage of the rectifier circuit 204b by the output voltage detection circuit 204d. When the output voltage of the rectifier circuit 204b becomes 3.6 V or less, the voltage of the secondary battery 104 is monitored by the output voltage detection circuit 204d. That is, CPU
Reference numeral 210 periodically executes the voltage monitoring program 213a and compares the terminal voltage of the secondary battery 104 obtained by the output voltage detection circuit 204d with a preset threshold voltage to detect the remaining battery level. (Step 20
1). When the remaining amount of the secondary battery 104 decreases and becomes equal to or lower than a specified inter-terminal voltage (3.3 V or lower), the CPU 210 executes the charge request processing program 213b to execute the charging request processing program 213b from the non-contact IC card 1 via the antenna coil 102. A charge request signal 41 is transmitted to the reader / writer (step 20).
2).

The IC card reader / writer 2 detects the charge request signal 41 (step 203), and
2 is transmitted to the non-contact type IC card 1 for a certain period (step 204). This makes contactless IC card 1
The side performs a charging process of the secondary battery 104 (step 20).
5). Then, the IC card reader / writer 2 stops the output operation of the electric power carrier (step 206). At this time, the power carrier 42 has a waveform only at the time of charging, which does not depend on the content of data to be transmitted and received. It is preferable to use a sine wave set to a specific frequency as the power carrier 42 because transmission loss can be reduced and the noncontact IC card 1 can efficiently take in power.
The transmission of the power carrier wave 42 from the IC card reader / writer 2 is stopped after a predetermined time has elapsed from the start of transmission to the non-contact type IC card 1. As the fixed period, for example, 10 seconds can be set. After the transmission of the power carrier wave 42 is stopped, the normal IC module 105 in the non-contact type IC card 1 returns to the state of monitoring the voltage between the terminals of the secondary battery 104, and the same operation as steps 201 to 206 is performed again. This operation is performed periodically until the battery is charged. When it is determined in step 207 that the battery is fully charged, the charge request signal 4
1 is completed. Note that when the power from the regulator 204 c is a voltage that can be used, including during reception of the power carrier 42, the power is particularly low when the IC module 1
05 and the like.

FIG. 6 shows an example of the charging operation of the secondary battery 104 by the charging / discharging circuit 203. In the charging, first, constant-current charging is performed, and then constant-voltage charging is performed (step 20).
1). In the constant current charging, charging is performed at a constant current value until the charging voltage reaches a specified voltage (step 202). When the charging voltage reaches the specified voltage, the operation shifts to constant voltage charging. If the charging elapsed time exceeds the specified time after starting the constant current charging, it is determined that the battery has an abnormality and the charging is terminated (step 203). In the constant voltage charging, charging is performed at a constant voltage until the charging current reaches a specified voltage (step 2).
04). The process ends when the charging current reaches the specified current.
As in the case of the constant-current charging, if the charging elapsed time exceeds the specified time after the start of the constant-voltage charging, it is determined that there is an abnormality in the battery, and the charging is terminated (step 205).

FIG. 7 shows an example of the power supply operation (discharge operation) of the secondary battery 104 by the charge / discharge circuit 203. The discharge of the load is started, and the discharge voltage is monitored (step 301). If the discharge voltage falls below the specified voltage, the discharge is stopped to prevent overdischarge (step 30).
3). Also, the discharge current monitors the specified current (step 3).
02), the discharge is stopped also when the value exceeds (Step 30).
3). After the discharge is stopped, the discharge is stopped before the discharge current or the discharge voltage falls within the specified value, and the power supply is stopped (step 304). When the value falls within the specified value, the process returns to step 301 as shown by the dotted line, and the power supply (discharge) is restarted. During power supply (discharging)
Constantly monitors the discharge voltage and discharge current (step 3
05).

Next, an actual example of a non-contact type IC card having such a charging / discharging circuit will be described. Using PET, length 54.0 mm, width 85.6 mm, thickness 0.76
In the non-contact type IC card 1 having the external dimensions of 4 mm, for example, the external dimensions of the secondary battery (polymer lithium) 104 are 43.0 mm in length, 60.0 mm in width, and 0.5 m in thickness.
It is assumed that m is used. The mass of the secondary battery 104 is 2.13
g, the voltage is 3.6 V, the capacity is 22.4 mAh, and when data is transmitted using the antenna coil 102, if a current of 10 mA at the maximum and an average of 3 mA are passed, the apparatus stands by without data transmission. In case, maximum 150μA,
An average current of 35 μA can flow. By these current values and the capacity of the secondary battery of 22.4 mAh,
In the case of only standby after the secondary battery 104 is sufficiently charged, it can last for about 160 days. Also, the secondary battery 104
If continuous data transmission is performed after the battery is fully charged, about 2.2 hours are possible.

As the core sheet 103, a magnetic core 301 having an opening 108 for accommodating a secondary battery and having a structure as shown in FIG. 8 can be used. The opening 108
Is an opening correspondingly provided for accommodating the IC module 105. In this example, an opening is provided here.
Module 105 is fitted. The magnetic core 301 is formed by arranging a large number of linear magnetic bodies (solid vertical line portions) coated with an insulator in parallel and parallel. The magnetic core 301 is made of a magnetic material having a magnetic permeability equal to or higher than a vacuum magnetic permeability. Used. Since a magnetic material having a magnetic permeability equal to or higher than the vacuum permeability is located inside the closed curve of the antenna coil 102, the magnetic flux density crossing the closed curve of the antenna coil 102 is increased, and the power supply transmitted by electromagnetic induction is more efficient. It is done on a regular basis. The magnetic material depends on the frequency band used for power transmission, but is preferably MnZn ferrite or NiZn ferrite. In particular, when the frequency is 13.56 MHz, NiZn ferrite is preferable. By the way, I
The C card preferably has a means for detecting the voltage between the terminals of the flexible secondary battery and converting the voltage to the remaining capacity. Further, a temperature detecting element is provided on and near the flexible secondary battery. May be arranged to stop the discharging and charging when the temperature becomes lower than the lower limit specified temperature or higher than the upper limit specified temperature. Further, in the embodiment, the polymer lithium secondary battery is taken as an example, but it goes without saying that another secondary battery or a capacitor for power storage may be used instead of the secondary battery.

[0028]

As described above, according to the present invention, the voltage value of the power received by the antenna coil by radio waves is monitored, and the power supply voltage is less than the movable voltage value in the power supply by radio waves. Sometimes the IC card is operated by the power from the secondary battery or the condenser, and when the voltage of the supplied power is equal to or higher than the operable voltage value, the secondary battery or the capacitor is charged by the surplus power during or after the operation via the charging circuit. To do it. As a result, when the voltage is less than the operable voltage value in the unstable power supply by the radio wave, the IC module is operated using the stable power of the battery or the capacitor without using the unstable power by the radio wave, and Since power is used for charging, power is not wasted. Moreover, even when the power received by the antenna coil by radio waves is used, excess power can be transferred to the charging side, so that even if the radio wave output is too strong, the IC module side can use stable voltage power. .

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment to which a non-contact type IC card of the present invention is applied.

FIG. 2 is an exploded explanatory view of the overall configuration example.

FIG. 3 is a flowchart of a non-contact type IC card charging and power supply operation.

4A and 4B are explanatory diagrams of the structure of a non-contact type IC card, in which FIG. 4A is a diagram illustrating the relationship between a core sheet and an antenna coil, and FIG. (C) is a cross-sectional view of the non-contact type IC card.

FIG. 5 is a flowchart of a power supply request transmission process when the supply voltage falls below a predetermined value in the power supply of the secondary battery.

FIG. 6 is an explanatory diagram of a charging operation of the secondary battery 104 by the charging / discharging circuit.

FIG. 7 is an explanatory diagram of a power supply operation (discharge operation) of the secondary battery 104 by the charge / discharge circuit.

FIG. 8 is an explanatory diagram of a structure of another core sheet.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Non-contact type IC card, 101 ... Top cover sheet
102: antenna coil, 103: core sheet, 104
... Secondary battery (polymer lithium secondary battery), 105 ... I
C module, 106 ... bottom cover sheet, 107a,
107b, 107c, 107d, 107e, 107f ...
Terminals, 108, opening, 201, IC card controller, 202, protection circuit, 203, charge / discharge control circuit, 2
04: power supply circuit, 204a: tuning circuit, 204b:
Rectifier circuit, 204c regulator, 204e supply power switching circuit, 210 CPU, 211 RAM, 212
.. ROM, 213 EEPROM, 214 input / output control circuit, 215 bus, 301 core.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G06K 19/00 J

Claims (10)

[Claims] 1. A non-contact type IC card having a secondary battery or a capacitor, an antenna coil, and an IC and receiving power obtained by radio waves received from the antenna coil, wherein the card is supplied via the antenna coil. Detecting means for detecting whether or not the electric power is higher than a voltage value operable as an IC card; a charging circuit for charging the secondary battery or the capacitor; and the supply power being movable in accordance with a detection result of the detecting means. When the voltage is less than a possible voltage value, the IC card is operated by the power from the secondary battery or the capacitor. When the supplied power is equal to or more than a operable voltage value, the IC card is operated by the supplied power and surplus power is supplied. Switching means for charging the secondary battery or the capacitor by the charging circuit. Mode. A rectifying circuit for rectifying a current signal from the antenna coil to generate power of a predetermined voltage; and a starting circuit for activating the IC, wherein the starting circuit is a weak predetermined signal. The antenna operates by receiving a current signal by a radio wave having a frequency of, via the antenna coil,
Charging the surplus power obtained through the rectifier circuit to the secondary battery or the capacitor during or after the operation of the IC card,
2. The non-contact type IC card according to claim 1, wherein the secondary battery is a polymer lithium having flexibility. 3. The method according to claim 1, wherein the supply power is less than a operable voltage value according to a detection result of the detection means, and the voltage of the power supplied from the secondary battery or the capacitor is less than a predetermined value. 3. The non-contact type IC card according to claim 1, further comprising transmitting means for transmitting a power supply request signal to a power supply side by radio waves. 4. The non-contact device according to claim 1, further comprising means for monitoring a charging current of the secondary battery, wherein the charging is terminated when the charging current falls below a predetermined current value. Type IC card. 5. The apparatus according to claim 1, further comprising means for monitoring a charging time of the secondary battery, wherein the charging is terminated when a predetermined charging time is reached. Non-contact type IC card. 6. The apparatus according to claim 1, further comprising means for monitoring a discharge voltage of the secondary battery, wherein the discharge is stopped when the discharge voltage falls below a specified discharge voltage. Non-contact type IC card. 7. The IC card according to claim 1, wherein the secondary battery is not exposed on any of the IC card surfaces.
7. The non-contact type IC card according to any one of 6. 8. A structure having a sheet-like substrate provided with said antenna coil, wherein said substrate is provided with an opening or a concave portion, said secondary battery is fitted, and is sandwiched between at least one of an upper portion and a lower portion by an insulating material. The non-contact type IC card according to claim 1. 9. The non-contact type IC card according to claim 1, wherein the secondary battery is located inside a closed curve of the antenna coil. 10. Inside the closed curve of the antenna coil,
The non-contact IC card according to claim 9, wherein the secondary battery and a magnetic material having a magnetic permeability equal to or higher than a vacuum magnetic permeability are arranged.