| 摘要 |
PROBLEM TO BE SOLVED: To provide an excellent effect in an improvement of performance of a head lamp by obtaining a required rigidity with a minimum necessary weight increase, generating no deformation on a resin reflection mirror during aiming and constantly obtaining a luminous intensity distribution characteristic of a normally correct form. SOLUTION: This resin reflection mirror 1 comprises reinforcement ribs 3c at least two of which are formed vertically on a rear surface while at least two of which are formed latterally thereon so as to be a lattice shape, wherein a ratio of a rib thickness D of the rib 3C to a fundamental wall thickness (t) of the resin reflection mirror 1 is in a range of 0.5<=(D/t)<=2.5, and a cross sectional area (S) of the rib 3C is in a range of 3<=S<=50 (mm<2> ). With such a constitution, the mirror 1 can obtain a required rigidity with a minimum necessary weight increase, improve the performance and minimize a cost increase. |
