| 摘要 |
PROBLEM TO BE SOLVED: To prevent yellowing and degrading of a synthetic resin lens caused by ultraviolet rays emitted from a light source, and maintain those functions for a long time. SOLUTION: A projector type head lamp for a vehicle is constructed such that a projection lens 10 made of glass is disposed at the inside of an outer lens made of synthetic resin, and light from an electric discharge lamp bulb is applied to the outer lens through the projection lens 10. In this head lamp, an ultraviolet ray absorption membrane 12 made of zinc oxide only is formed at the inner surface 10a of the projection lens 10. It is desirable that a thickness of the ultraviolet ray absorption membrane 12 is set within the range of 0.5μm-0.7μm.
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