| 摘要 |
PURPOSE:To easily restart communication even if no light beam of an opposite station is received by using an optical system whose transmission/reception light angle is variable for an optical system of a transmission/reception device and varying the transmission/reception light angle depending on the detection of a signal light from the opposite station. CONSTITUTION:Both a station 20 and a mobile robot 21 have a transmission and reception device 13 in its tracking drive device 14 and apply optical radio transmission while matching the optical axes. If the robot 21 rapidly directs its direction rapidly or the direction of the optical axis is changed largely due to any cause, the signal light of the opposite station is not received by a 2-dimension optical sensor 5 of the device 14. Then a CPU/memory section 9 issues a command to a zoom lens drive control unit 8 to zoom zoom lens groups 1,2 via a zoom lens drive section. In zooming the zoom lens wider, the light receiving angle is increased, the light emitting beam is spread and when the position of the light transmission and reception device 13 enters the photodetecting plane of the sensor 5, it is detected. When the position of the opposite station is detected, the tracking control is applied while zooming the zoom lens to attain accurate optical axis alignment. |
