| 摘要 |
PROBLEM TO BE SOLVED: To form an antireflection film on a substrate having a high refractive index. SOLUTION: An alternate multilayered film 20 having a six-layer structure is formed on a substrate 10 having, for example, > 2.0 refractive index. The layers are first, third and fifth layers 21, 23, 25 as high refractive index layers having a lower refractive index than that of the substrate, second and fourth layers 22, 24 as medium or low refractive index layers, and sixth layer 26 as a low refractive index layer. The optical film thickness of each layer is optimized. Even when the substrate 10 has a high refractive index, an antireflection film having <=0.5% reflectance in the whole visible ray region can be obtained. |
