| 摘要 |
PROBLEM TO BE SOLVED: To reduce generation of fogging or shining in the case where a light guide is expanded by heat.SOLUTION: A light guide includes a plurality of boss parts. In the vicinity of the center of a base part 201 for fixing the light guide, round holes 211a, 211b are provided and in both end portions, slits 213a, 213b, 213c, 213d are provided. The round holes 211a, 211b support the boss parts both in a length direction and in a width direction of the light guide. The slits 213a, 213b, 213c, 213d support the boss parts in the width direction of the light guide but do not support them in the length direction. Namely, since the center of the light guide is fixed in both the directions, both the end portions of the light guide are expanded to escape with respect to the length direction. Thus, influences of expansion can be reduced by half. |
