| 摘要 |
PROBLEM TO BE SOLVED: To reduce electric currents consumed by a card for extending a card life when the life of a card is limited according to the life of a battery in the case that a battery is not exchanged for a non-contact IC card incorporating a battery as a power source of the card. SOLUTION: A signal strong enough for eliminating the need of an amplifier with relatively large current consumption is intermittently transmitted from a read/write device 1 to a received strength detecting circuit of a card 2, without using any amplifier with relatively large current consumption for the received strength detecting circuit of the card 2. Thus, the intermittently transmitted strong signal is detected by the received strength detecting circuit, and a power source of the card 2 is activated, and a power is supplied to a circuit or the like necessary for communication. Also, when the intermittent signal is not detected for a certain time, power supply to parts other than the detecting circuit is stopped. |
