| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a reader/writer and control method thereof for reducing the power consumption when no communication is made between the reader/writer and a wireless card. <P>SOLUTION: The reader/writer is provided with: a transmission means 110 for transmitting an electromagnetic wave received by the wireless card 200; a reception means 120 for receiving a return signal; a transmission control means 130 for outputting a transmission stop signal indicative of transmission stop of the electromagnetic wave to a transmission means when a succeeding return signal is not received within a detection time being a prescribed time from a reception point of time of the return signal, outputting a signal instructing transmission start of the electromagnetic wave to the transmission means after a lapse of a stop time being a prescribed time from a point of time when the transmission stop signal is outputted, and continuing the transmission of the electromagnetic wave until a lapse of a succeeding detection time when the succeeding return signal is received within the detection time; and a time measurement means 140 for measuring the detection time and the stop time, and when the reception means does not receive the return signal from the wireless card 200, the reader/writer stops the transmission of the electromagnetic wave. <P>COPYRIGHT: (C)2004,JPO |
