| 摘要 |
PURPOSE:To improve the durability of a sensor for light volume, by applying a surface hardening agent containing an ultraviolet-absorbing agent onto a sensor light receiving section. CONSTITUTION:In a light volume sensor 3 used for an automatic lighting apparatus for a head light, a surface of a plastic having a haze of 50-95% is provided with a light receiving window on which a surface hardening agent containing an ultraviolet-absorbing agent is applied. Thus, a sensor for light volume that is durable and high in reliability can be obtained. |
