| 摘要 |
PROBLEM TO BE SOLVED: To increase quantity of light fetched in the inner part of a light guide body and to enhance the utilization efficiency of the light by tilting the inner wall surface of an end face side of a light source insertion space in both directions X and Y, so that a tilted reflection surface capable of reflecting the light from a light source in a direction reverse to the end face side is provided. SOLUTION: The 1st tilted reflection surfaces 21 and 21 are provided at a part of the inner wall surface of the end face 12c side of the light source insertion space 18. The reflection surfaces 21 and 21 are tilted in both directions X and Y and formed in a direction that the light from the light source 13 can be reflected in the direction reverse to that of the end face 12c. The light is radially emitted to an X-Y plane from the light source 13. Many components of the divergent light within the range ofαout of the light from the light source 13 are reflected by the reflection surface 21 and become reflected light beams La and Lb. A part of the light is made incident on the light guide body 12 from the reflection surface 21 and reaches a curved surface R. Many components of the light going toward the curved surface R are reflected in the direction X by the reflection surface 21.
|
