| 摘要 |
PROBLEM TO BE SOLVED: To enable a reader/writer for ID tag to surely communicate with an ID tag by avoiding the influence of environmental noise. SOLUTION: While an ID tag used for a reader/writer for ID tag makes transmission by generating a transmitting frequency (62.5 kHz) by halving the receiving frequency (125 kHz) from the reader/writer, the tag makes the transmission by also generating a transmitting frequency (187.5 kHz) as the reflection of the frequencies. Since the MPU of the reader/writer measures the level of the environmental noise corresponding to the transmitting frequencies of the ID tag and the transmitting frequency which is lower in environmental noise level is made to pass by a command given to DSP 37, the reader/writer can surely communicate with the ID tag by raising the S/N. |
