REFLECTION MIRROR FOR AUTOMOBILE

摘要

PURPOSE:To obtain a desired color tone at a low cost and to prevent the driver's fatigue owing to the dazzle by forming transparent thin dielectric films having different refractive indexes on base glass then forming a metallic film thereon. CONSTITUTION:The 1st transparent thin dielectric film 2 (refractive index n=2.3) consisting of MgF2 having a low refractive index is deposited by vacuum evaporation on base glass 1 (n=1.53). The 2nd transparent thin dielectric film 3 (n=2.3) consisting of TiO2 having the refractive index higher than the refractive index of the glass 1 is deposited by vacuum evaporation on the surface of the film 2. A metallic film 4 consisting of a nickel-chromium alloy to serve as a reflecting surface of light is deposited by vacuum evaporation at a desired film thickness on the surface of the film 3. When light is made incident to such reflection mirror from the direction of an arrow L, the light of the quantity determined by the difference in the refractive indexes is reflected at the boundary between the glass 1 and the film 2 and the boundary between the film 2 and the film 3. The reflected light and the light reflected on the surface of the film 4 interfere with each other, by which the spectral characteristic of the reflected light is not made flat and the effect of coloring and preventing the dazzle is obtd.