| 摘要 |
PURPOSE:To execute an optical space communication without being subjected to a fault of disturbance light, by selectively switching a communication line. CONSTITUTION:In case when disturbance light B has been generated, a communicating signal to a moving body 12 from the ground is switched to the side of a light emitting device 14 by a switching device 26. Subsequently, an optical signal is sent to a photodetector 16 of the moving body 12 from this light emitting device 14, and communication is executed. In the same way, in case when disturbance light C has been generated, said signal is switched to a communication line provided between a light emitting device 13 and a photodetector 15, and communication is executed. At the same time, in the moving body 12 side, too, one of the photodetectors 15, 16 is selectively switched by a switching device 28, and a receiving signal is sent to a receiver 30. Especially, as for sunlight which causes a harmful fault, the time causing the disturbance light B or the disturbance light C is almost definite. Accordingly, by use of timers 27, 29, the signal is selectively switched automatically to a communication line of the side which is not subjected to a fault by a time, for instance, in the morning, in the afternoon, etc. |
