| 摘要 |
PROBLEM TO BE SOLVED: To allow the receiver installed in a mobile object to surely receive a transmission signal even when a transmitter adopts the millimeter wave communication system or the optical space communication system. SOLUTION: In the case of receiving an optical signal sent from a transmitter adopting the optical space communication system, an optical signal reception section 10 consisting of a condenser lens 11, a light receiving element 12, a pre amplifier 13, a band limit filter 14, a limiter and demodulator 15 receives the signal and the received signal is given to a signal automatic selection circuit 31. Furthermore, in the case of receiving an optical signal sent from a transmitter adopting the millimeter wave communication system, the signal is received by a millimeter signal reception section 20 consisting of a millimeter wave reception antenna 21, a down-converter 22, an intermediate frequency amplifier 23, a band limit filter 24 and a demodulator 25 receives the signal and the resulting signal is given to the signal automatic selection circuit 31. The signal automatic selection circuit 31 detects the presence of an output signal from the optical signal reception section 10 and the millimeter wave signal reception section 20, selects either reception section from which the output signal is detected and provides an output of the output signal to an external output terminal 33 via a video amplifier section 32. |
