| 摘要 |
<P>PROBLEM TO BE SOLVED: To reproduce a transmitted data signal of an IC card always correctly. <P>SOLUTION: A non-contact IC card reader is equipped with an antenna 13 which receives a signal outputted as a radio wave from a loaded IC card 11 and having the transmitted data signal including a plurality of waveforms 30 superposed on a carrier, a rectifier circuit 22 which rectifies the signal received by the antenna, a detection circuit 23 which detects the envelope of the rectified signal outputted from the rectifier circuit, a differentiating circuit 26 which differentiates the detection signal including AC waveform components corresponding to the waveforms outputted from the detection circuit, and a comparator circuit 25 which compares the signal level of the output signal of the differentiating circuit with a specified threshold voltage and outputs the comparison result as a reception data signal corresponding to the transmitted data signal of the IC card. <P>COPYRIGHT: (C)2004,JPO |
