| 摘要 |
PURPOSE:To reduce the difference between light and darkness on the boundary between a Projection light radiation area and a nonradiation area by forming a diffusion step on the boundary between an outgoing light transit region from the injection lens of an outer lens and the other region. CONSTITUTION:A projection light transit region 12A having a circular shape slightly larger than the diameter of a projection lens 36 and no step is formed in the region faced to the projection unit 30 of an outer lens 12. A diffusion step S3 diffusing the light in the vertical direction is formed in a circular arc- shaped lower region 12B in the projection light transit region 12A of the outer lens 12. The curvature of the step face of the diffusion step S3 against the vertical plane is made larger toward the lower section, the incident light into the diffusion step forming region 12B is diffused and distributed downward when it goes out as shown by a symbol 1, and the excessive difference between light and darkness on the boundary region between a radiation area and a nonradiation area is reduced. |
