JPS62254252A - Ic card - Google Patents

Abstract

PURPOSE:To perform the replacement of data holding batteries without interrupting the holding action of memory data by incorporating a large capacity capacitor into an IC card. CONSTITUTION:An IC card contains a connector 6 for an external electronic equipment, a data holding S-RAM 1, a bus controller 8 for the S-RAM 1, an Li battery 3 which holds data in the single unit state of the Ic card, and a large capacity capacitor 2 set in parallel to the controller 8. The capacitor 2 is charged as soon as the S-RAM 1 is actuated by the power supply applied to the IC card from the external electronic element when the card is connected to the electric equipment. While the electric charge of the capacitor 2 charged in an action mode of the S-RAM 1 is discharged when the battery 3 is replaced. Thus the data on the S-RAM 1 are preserved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC card used as an external storage device for a portable computer or a personal word processor.

[Prior art 0 technology] The conventional OxC card 0 structure has a RAM for storing data and
A primary battery that performs the K storage operation, or one or more of such primary batteries, is built in and is supplied from the 9 cartridge 02 part.

[Problem that the invention seeks to solve]

However, with the above-mentioned conventional technology, when the battery zero capacity decreases and the memory O data retention operation no longer functions normally, the internal capacity of the IC card can be reduced without interrupting the memory data retention operation. There was a problem in that it was impossible to replace a battery that had run low.

Therefore, the present invention aims to solve these problems.
An object of the present invention is to provide an IC card in which a data retention battery of a memory can be replaced without interrupting the data retention operation of the memory even when the IC card is in a cassette state.

[No means for solving the problem] In order to solve the above problem, the present invention provides a static R
AMt- Battery ft that allows data retention operation P11'' to be performed on an IC card that retains data using a battery.
This device is constructed with a built-in large-capacity capacitor in order to continue data retention even when the battery is removed from the IC card for replacement.

[Effect]

As mentioned above, in addition to Mesosu's data retention battery O,
A capacitor with a larger capacity than the capacitor normally used in QIC cards to absorb power supply voltage fluctuations, etc. is built in parallel with the battery for data retention operation, so the capacity is reduced by 0. For the purpose of replacing the battery that was
Even if the card is removed from the C card, the charge stored in the large capacitance capacitor makes it possible to retain O data in the memory.

〔Example〕

Therefore, details of the present invention will be described below based on examples.

FIG. 1 is a block diagram showing a row of IC cards according to the present invention.
In AM, this IC card is connected to electronic equipment etc. using the connector 6t and exchanges electrical signals.
Power for the IC card to perform a data storage operation when the conductor is in the O state is supplied from the main battery 3 through the current limiting resistor 7t.

The diodes 4 and 5 are used to prevent leakage current from the IC card and damage caused by charging of the IC card. The large capacity capacitor 2 of the present invention is s-:
aAn1z Parallel with pass capacitor 8 (provided i. Figure @2 is a structural diagram of an IC card configured by %W
The OS can be removed from the card base lO! ! The structure allows for easy pond replacement.

Next, the operation of the IC card constructed in this way will be explained.

Electronic using IC card by FJA! When connected to the IL device, the IC card's 08-RAM is transferred from the child @ device.
Operating power is supplied to the device and it becomes accessible. In this state, the IC card can read and write data and programs as part of an external auxiliary storage device or main memory of an electronic device. At this time,
Electronic! ! The voltage is applied to the IC card from the device! 5! (Therefore, at the same time as the B-RAM operates, the large capacity capacitor is also charged. However, due to the diode, the charging current for the 111 battery does not flow,
Prevent damage to batteries caused by photoelectricity and protect electronic equipment and the human body! It is something that does I.

Then, after using the IC card, remove it from the electronic device or turn off the power to the electronic device, and perform B-RAMQ operation on the IC card. source. Q
In this case, 8-RAM performs data storage operation by OLi Kameike inside the IC card.5. At ζ0, the diode 5 in Figure 1 is connected to an electronic device and when power is not applied to the IC card, L (0 current from the battery leaks to the outside of the IC card Q and becomes an electronic This is to prevent the L7 battery's capacity from decreasing as it is consumed by the internal circuit of the device, and to extend the data storage operation period of the Lj battery as long as possible.However, the L7 battery's capacity is normally If the battery needs to be replaced, data storage operation cannot be performed and the IC card's internal O data is no longer guaranteed. Then, I.C.
The Lj battery had to be replaced while the B-RAM operating type i2N was applied to the card from the outside.

This can be achieved by connecting the IC card to an electronic device or to a dedicated aS that applies only operating power.

However, in the present invention, even when replacing the L4 battery due to a decrease in capacity, the K L
i Even if you remove the battery from the IC card, the B-RAMO
The 8-RAMQ data storage operation can be continued by discharging the large capacitor Ot charged during operation. The time during which the 5-RAM data storage operation can be performed using only this large-capacity capacitor can be determined by setting the large-capacity capacitor to 0, taking into account the 8-RAM0 current consumption and battery O operation time, etc. It can be set arbitrarily by the designer.

When the Lj battery is replaced, the initial voltage of the new Lj battery Q exceeds 3V, and due to discharge, the discharge voltage of the large capacity capacitor has decreased to 3V or less.

Thereafter, the discharge of the large capacity capacitor will be stopped, and the source for the B-R MO data storage operation will be supplied from the IIi battery.

[Invention ■ Effect]

As explained above, according to the present invention, by incorporating a large capacity capacitor into an IC card together with an r, +jll battery, %Lj! If the capacity of the E-cell 3 decreases and the data retention operation of the memory no longer functions normally, the IC card internal capacity will be reduced without interrupting the data retention operation of the memory. It becomes possible to exchange.

In addition to taking the battery out of the IC card for the purpose of replacement, in the unfortunate event that the IC card is dropped, the battery case 9 and battery contacts may come off, causing data inside the memory to be lost. It is also possible to protect the data inside the IC card from serious accidents.

[Brief explanation of drawings]

Figure K1 is a block diagram of the OIC card 0 of the present invention. Figure 2 shows the IC card we created based on Figure 1.
It is a diagram. 1...8-RAM 2...-Large capacity capacitor 3-...Lj [Pond 4, 5...Diode 6...! Birth 7... Resistor 8... Pass capacitor 9... Lu1l pond case 10... IC card base or more

Claims (1)

[Claims] An IC card in which a static RAM performs a data retention operation using a primary battery such as a lithium battery built into the IC card, and is characterized by having a built-in large-capacity capacitor in addition to the primary battery.