| 摘要 |
PROBLEM TO BE SOLVED: To realize communication in a wide range by defecting the intensity of a radio wave by means of a level detection circuit part and controlling a detection circuit by adjusting it in conformity with the intensity. SOLUTION: A radio wave from an outer device is received by an antenna part 7 and the bridge circuit of a rectification circuit part 2 generates the driving power of a non-contact IC card, changes the amplitude of a sine wave in proportion to the intensity of the radio wave and changes the level of power. Thus, a level detection circuit part 3 detects the intensity of the radio wave from the level of power. A detection circuit part 1 adjusts a time constant by adjusting it in conformity with the intensity of the radio wave by information from the circuit part 3 and detects a clock signal by half-wave rectification from a sine waveform. A modulation/demodulation circuit 4 converts the detected clock signal into data of a command and the like. Converted data is transmitted to a control circuit part 5 and the command is judged and the data is transmitted to a memory part 6 and the command is executed. Even if the intensity of the radio wave changes, communication in a wide rang can be realized. |
