| 摘要 |
PURPOSE:To avoid malfunction or deficient sensitivity or the like from being caused by using two photodetectors so as to cancel a light from lighting fixtures. CONSTITUTION:The photodetector 1 is arranged on a front part or the like of a receiver such as a television receiver and the photodetector 5 is arranged at a position at the side face or upper face or the like of the television receiver where no signal light is reached from a remote control transmitter. Thus, the photodetector 1 receives the signal light and the light from lighting fixtures and the photodetector 5 receives the light of lighting fixtures only. Thus, the light from lighting fixtures inputted to both photodetectors 1 and 5 is cancelled by a differential amplifier 7 and when the signal light exists, only the signal light component is outputted from the differential amplifier 7 without being disturbed by the light from lighting fixtures. |
