| 摘要 |
PURPOSE:To bring the fluctuation time of an output amplitude in a short time to a degree not to be detected by human eyes by transmitting a signal in a transmission system performing electrooptic conversion while cutting off a low frequency component, and recovering the low frequency component being cut off by the transmission system in a reception system performing photoelectric conversion. CONSTITUTION:A ultralow frequency component is cut off from a video electric signal inputted to a terminal IN Of the transmission system 1 by a coupling capacitor 11 and enters an LED drive amplifier 12. An LED13 is operated by an output signal of the amplifier 12 to output a video optical signal. A picture converted into an optical signal is set to the reception system 2 via a fiber transmission line 30. The video image signal is converted into an electric signal by a photodetector 21. A clamp 23 detects a synchronizing pulse to obtain a mean DC level and the mean DC level is inverted and superimposed on the signal converted into the electric signal. The low frequency component cut off at the transmission side is recovered at the output of the clamp 23. |
