OPTICAL SPACE TRANSMISSION SYSTEM

PURPOSE:To prevent reception disturbance with an infrared ray emitted by itself by combining plural sets of light emitting elements and light receiving elements whose emission angle characteristics differ from each other so as to adjust a light distribution characteristic thereby obtaining a desired communication available range. CONSTITUTION:Inter-on-road vehicle communication is executed between an on-road device 1 and an on-vehicle device 6. A light emitting and light receiving device 4 having a light emitting section and a light receiving section of the on-road device 1 is fitted to an arm 3 stretched on a road so as to be correspondent to a drive track 5, and a controller 2 allows the light emitting section to emit an infrared pulse ray onto a road face. On the other hand, the on-vehicle device 6 is mounted with a light receiving and a light emitting device 7 having a light emitting section and a light receiving section and with a controller 8. The light emitting section of the light emitting device 4 on the road side is made up of the combination of plural light emitting elements and emits an infrared pulse ray having a light distribution pattern covering only required tracks. That is, the light emitting elements and the light receiving elements with a narrow emission angle are arranged around the light receiving elements having 2 wide light, emitting angle to obtain the directivity covering a desired range, then the limited range is easily covered.