| 摘要 |
PROBLEM TO BE SOLVED: To enable transmitting and receiving data of a specific noncontact medium to and from a reader/writer by using a receiving device by disconnecting receiving devices for other media, except the specific noncontact medium by a disconnecting device once an overlap detecting device detects an overlap. SOLUTION: An LC parallel resonance circuit 15 constitutes the receiving device for a noncontact medium A, and this device is used to send and receive data. Further, the overlap detection part 22 detects the noncontact media A... overlapping with one another. Once the overlap detection part 22 detects the overlap, a resonance capacitor disconnecting means 23 disconnects a resonance circuit 15 constituting receiving devices for other media other than the specific noncontact media A. For example, when the output waveform of the resonance circuit 15 is less than a specific value, the presence of an overlap is detected. Then a medium having 'order 1' stored in a RAM 26 as the foremost information allowing transmission or reception foremost is set as the medium A and the resonance capacitor 14 for a medium with unstored 'order 2', etc., is disconnected from the device. |
