| 摘要 |
PROBLEM TO BE SOLVED: To preclude the possibility of taking an optical beam for a red traffic signal of train operation even in the case of using a forward light receiving system, and further to prevent an output level decline of a light emitting element. SOLUTION: The space transmission optical communication transmitter projects a light beam from a front side in the progressing direction of a mobile body against a light receiver placed on the mobile body. The optical system consists of a near-infrared ray diode 31, a condenser lens 32 and an optical filter 33. Near-infrared ray outputted from the near-infrared ray diode 31 is collected by the condenser lens 32 and outputted as an optical beam 21 into air space via the optical filter 33 that cuts off a visual light region. |
