| 摘要 |
PURPOSE:To exclude interference when plural transmission means are employed by superimposing a carrier onto a transmission pulse signal in a centralized controller or each stationary transmitter-receiver so as to completely synchronize the transmission timings of the optical signals with each other. CONSTITUTION:A centralized controller 5 sends a transmission pulse signal (s) to a stationary transmitter-receiver 1a, and an output of the controller 5 superimposed on a carrier (c) is provided as an output to the transmitter-receiver 1a. A light projector 12 in the internal circuit of the transmitter-receiver 1a provides an output of the signal received by its amplifier 11 without changing the timing of the pulse. The optical signal is projected from projectors provided to other stationary transmitter-receiver sets 1b, 1c in the same timing. As a result, the optical transmission is implemented in the same timing in all the area. Each stationary transmitter-receiver converts an input signal into the optical signal only and the emitted optical signals are completely synchronously with each other and no interference due to deviated timing even in an overlapped region is caused. |
