| 摘要 |
PURPOSE:To eliminate the need for optical filters in an optical transceiver and an image receiver by allowing only the frequency component of a modulated carrier of the electric signal outputted from a light receiving part to pass through a filter circuit and demodulating the modulated carrier, which passes through this filter circuit, in a demodulating circuit part to reproduce a video signal. CONSTITUTION:The optical signal transmitted from an optical transceiver 30 is set to a short wavelength, and the video signal in the base band is FM-modulated and is converted to an optical signal in a long wavelength band and is transmitted from an optical transmitter 40 for video. The transmission band of this video signal is made higher than that of the optical signal in the short wavelength band transmitted from the optical transceiver 30 and only the frequency component corresponding to the video signal of the optical signal received by an optical receiver 50 for video is selected by a filter circuit 52 and is demodulated to reproduce the video signal in the base band. Thus, the optical transceiver 30 receives only the optical signal in the short wavelength band without using optical filters and the optical receiver 50 for video eliminates the influence of the optical signal in the short wavelength band to reproduce the video signal of high S/N. |
