| 摘要 |
PROBLEM TO BE SOLVED: To enhance the resistance to dust, etc., to increase the strength to environmental change such as temp. change and to facilitate free attachment/ detachment of a circuit substrate, by refracting signal light made incident from a position coming near to a side surface of one side terminal edge in the direction parting from this one side surface and diffusing the refracted signal light into an optical data bus. SOLUTION: In the optical data bus 10, since the end surface 13 of a signal light incident part 11 side of formed in a circular arc shape, a signal light made incident from the position coming near to one side end surface (side surface 17 to side surface 18) is refracted in the direction parting from this one side surface, that is, in the direction facing the center of a signal light emission part 14, and this refracted signal light is diffused by a light diffusion layer 12. The diffusion characteristic of the light diffusion layer 12 is nearly equal to a perfect diffusion characteristic. Thus, when the signal light emitted from e.g. a light emitting element 19 is made incident on the signal light incident part 11, the signal light with the largest intensity among the signal light diffused by the light diffusion layer 12 is propagated toward the central part of the signal light emission part 14. |
