| 摘要 |
PURPOSE:To eliminate reflection light components and make band-narrowing possible by transmitting signals in the base band from one direction and transmitting modulated signals from the opposite direction and overlapping these two frequency bands with each other partially. CONSTITUTION:Light signals are received by light receiving element 6 and are displayed on display device 7 through amplifier circuit 20, low-pass filter 21, horizontal scanning period delay circuit 23 and adder circuit 24 (comb line filter 22). Meanwhile, received signals enter synchronization separation circuit 25 and are separated into vertical synchronizing signals V and horizontal synchronizing signals H to drive video signal generator 14. Singnals H are supplied to modulation carrier generator circuit 26 and become modulation signals in modulator circuit 24 and generate opposite- direction light signals by light emission element 15 through band pass filter 28 and light emission element driving circuit 29. |
