| 摘要 |
PROBLEM TO BE SOLVED: To provide an antireflection film exhibiting excellent antireflection performance in a wavelength band from 390 to 720 nm that exceeds a conventional antireflection band width of 300 nm.SOLUTION: The antireflection film includes first to ninth layers deposited in this order on a surface of a substrate, in which the second, fourth, sixth and eighth layers are high refractive index layers formed of a high refractive index material showing a refractive index of 2.21 or more and 2.70 or less to d-line at a wavelength of 587.56 nm; the first, third, fifth and seventh layers are medium refractive index layers formed of a medium refractive index material showing a refractive index of 1.40 or more and less than 1.55 to the d-line; and the ninth layer is a low refractive index layer formed of a low refractive index material showing a refractive index of 1.35 or more and less than 1.40 to the d-line. The antireflection film has a reflectance of 0.2% or less to light in a wavelength band from 390 to 720 nm in a visible region. |
