| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of an overlapping area of light concerning an irradiated area from the constituting area of a reflection surface to a lens as much as possible, and facilitate the design of a lens step by devising in the shape design of the reflection surface. SOLUTION: The reflection surface 3 of a reflector 2 is composed of an area 3U which is positioned approximately over a horizontal plane out of the reflection surface 3 of the reflector 2 when the reflector 2 is divided into two by the horizontal plane including the main optical axis of the reflector 2 and further one part thereof extends approximately under the horizontal plane, and an area 3D which is positioned under the horizontal plane including the main optical axis of the reflector 2. The spread of reflection light in a horizontal direction by areas 3DL1, 3DR1 positioning near the main optical axis of the reflection surface 3 out of the area 3D is set to be smaller comparing with the spread of reflection light in a horizontal direction by areas 3DL2, 3DR2 positioning near the periphery of the reflector 2 so that no overlapping or little overlapping of an irradiation area 6U to a lens 5 by the area 3U and an irradiated area 6D to a lens 5 by the area 3D is allowed. |
