| 摘要 |
PROBLEM TO BE SOLVED: To obtain an equipment accurately transmitting data even when the propagating state of a transmission path is not satisfactory by providing each means of reception, clock generation, demodulation, signal generation and sampling. SOLUTION: In a reader/writer 500, a modulation/demodulation circuit 530 modulates a carrier signal with a command reading out ID and effective limit data from a noncontact IC card 600 under the control of a control part 510 by the instruction of a computer 400. The carrier signal modulated with the command is radiated from a transmission and reception antenna 520 as a radio wave. This radio wave is received by the transmission and reception antenna 610 of the noncontact IC card 600 and an induced high frequency signal is sent to a demodulation circuit 620 to demodulate the command. The demodulated command is converted to a parallel command by a serial/parallel converter 640 and sent to an input/output buffer 680. |
