| 摘要 |
PURPOSE:To obtain an antireflection film of a large area at a low cost by laminating coating layers different from each other an mixing ratio between the constituents to form a film whose refractive index changes continuously. CONSTITUTION:A glass substrate, MgF2 as a substance having the lowest refractive index and a substance having a refractive index between the refractive index of the glass substrate and that of MgF2, e.g., SiO2 are prepd. Superfine SiO2 particles 2 are mixed with superfine MgF2 particles 1 and the glass substrate 3 is coated with the mixture while changing the mixing ratio in the direction of the thickness of the resulting film. The amt. of the SiO2 particles 2 is gradually reduced from the surface of the substrate toward the surface of the film and the malt of the MgF2 particles 1 is gradually increased. The change of refractive index at the interface between the film and the glass substrate is made gradual, a significant antireflection effect is produced and an antireflection film of a large area is formed at a low cost. |
