| 摘要 |
PURPOSE:To normally operate a remote control device while alleviating obstruction caused by a high frequency fluorescent lamp by switching the frequency of the remote control device to the frequency with least influence while varying the frequency of the remote control device. CONSTITUTION:A remote control IC 1 for transmission applies a key signal to a signal generation part 9 by the key operation of a key pad 8, and the signal generation part 9 generates a code signal corresponding to the applied key signal. A modulation part 10 modulates carrier wave generated by an oscillation part 11 by the code signal, and outputs a modulation signal to be applied to the transmission part composed of an light emitting element 2 and its driving circuit 3. The reception part amplifies a received remote control signal by an amplification part 20 to be applied to a detection part 21. Resonance circuits 16, 17, and 18 corresponding to the oscillation frequency differing in transmitters respectively are provided in the detection part 21, takes out signal components while resonated to the frequency of the carrier wave of the transmitted remote control signal to be detected by switching a changeover device 19, and detects and outputs the code signal of the remote control device. |
