| 摘要 |
PURPOSE:To prevent interference to realize long distance transmission even at the time of using plural systems using an LED in parallel, to directly transmit a signal such as a Manchester code by radio, and to provide an effective and convenient optical axis adjusting method. CONSTITUTION:An LED 12 is arranged at the focus position of a parabola reflector 11 of a transmitter 10 or the neighborhood of the focusing position, and the outgoing light of the LED 12 is reflected by the reflecting surface of the paradolic reflector 11 so as to be a parallel light. A pin photodiode 22 is arranged at the focus position of a parabolic reflector 21 of a receiver 20, and the light reflected by the parabola reflector 21 is converged to the focus position, and received by the pin photodiode 22. Also, an optical axis is adjusted by using an optical level detector, light emitter or light receiver whose directivity is wider than the transmitter 10 or the receiver 20, and constitution in which the two parabolic reflectors for transmission and reception are integrated or the like. |
