| 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 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, an A/D converter 25 which converts the detection signal outputted from the detection circuit from analog to digital, a waveform memory 27 which stores the waveform of the detection signal after the A/D conversion, threshold detection means 32 and 33 which statistically calculate thresholds for binarizing the detection signal from the waveform of the detection signal stored in the waveform memory, and binarizing means 34 and 35 which binarize the waveform of the detection signal stored in the waveform memory with the calculated thresholds and output the results as digital reception data signals corresponding to the transmitted data signal of the IC card. <P>COPYRIGHT: (C)2004,JPO |
