| 摘要 |
<p>PURPOSE:To make it possible to indicate a time for battery replacement with an IC card itself by providing an indication device on the card. CONSTITUTION:An IC card consists of a memory device and a control part which controls the input/output processing of data in the memory device. The memory device and the control part are driven by a built-in battery. An output voltage of the battery 104 is detected by a voltage detection circuit 105. The voltage detection circuit 105 consists of a comparator which compares a reference voltage with an output voltage of the battery 104 with a zener diode. If the output voltage of the battery 104 becomes lower than a specified reference voltage, a time for replacement of the battery 104 is indicated or warned by lighting or flashing LED 106. In addition, if, for example, a solar cell 105' is provided and the voltage detection circuit 105 and LED 106 are driven using the cell 105', the battery 104 lasts longer than when the cell 105' is not provided and the time for replacement of the battery is indicated or warned.</p> |
