PURPOSE:To achieve an effective use of light beam by utilizing one light beam for tracking and transmission of information. CONSTITUTION:A fixed station 1 includes a light beam generator 10, a reflective tracking apparatus 30 and a beam detector 60 and a mobile station 2 made up of a corner cube 100 and a light receiver 400. Light beam generated by the generator 10 is modulated with a modulator 20 based on information such as control signal of the moving body 2 and emitted to the mobile station 2 as light beam LB1. The beam LB1 is branched off with a spliter 200 and a part thereof enters the light receiver 400. A feedback beam LB' reflected from the corner cube 100 is incident to the detector 60, which drives the device 30 based on the beam detected, thus automatically tracking the mobile station 2.
展开▼
