| 摘要 |
PURPOSE:To reduce the occurrence of flaws due to impact and the mechanical aging change such as warp due to the variance of temperature, by providing a protection film consisting of a high-hardness metallic thin film on a metallic reflective film. CONSTITUTION:A protection film 4 consists of a high-hardness metallic thin film. Aluminum, titanium, copper, phosphor bronze, or the like is used as materials of the protection film 4 and is stuck to a metallic reflective film 3 by an adhesive. Though aluminum has an advantage in being lightweight and easy to use, titanium, copper, and phosphor bronze are superior to it in strength. The thinner the metallic thin film, the better; but a proper thickness is 0.03-0.5mm. in consideration of the surface precision. An epoxy resin or the like is adopted as the adhesive. |
