| 摘要 |
PROBLEM TO BE SOLVED: To contrive a sight recognition capability in a long distance and a middle distance by obtaining a sufficient irradiated light amount for an area in the vicinity of a slope cut-off line in a light distribution of passing beam. SOLUTION: In the case of viewing a reflecting surface 10 in an optical axis, in a first reflecting region 10B close to a horizontal criterion surface (x-y plane), it sets a criterion curve within a slope criterion surface tilted into the same angle as that ofθcol for a horizontal line of a cut-off line tilted against the corresponding criterion surface. Also, in second reflecting regions (10D, 10E) positioning at the upper side or the lower side than the first reflecting surface 10B against the horizontal criterion surface, it sets a criterion curve within a slope criterion surface tilted while having a second angle larger than 0 deg. against the horizontal criterion surface and also smaller than an angle against the horizontal line of the slope cut-off line. It forms a curve surface by giving a parabolic line within a plane orthogonal to the corresponding slope criterion surface.
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