Patent ID: 8481148
Filing Date: 2013-07-09
Classification: G02B,Y10T

Abstract:
1. A spectacle lens comprising: an optically transparent substrate; and an antireflection film formed on at least one surface of the substrate, wherein the antireflection film is formed by alternately laminating a low refractive index layer and a high refractive index layer, such that a plurality of low and high refractive index layers are alternately formed on the substrate, the antireflection film has a reflectance of 10% or less and an excitation purity range of 10 or less for visible light in a wavelength range from 380 nm to 780 nm incident at an incident angle ranging from 0° to 45° when regarding the direction perpendicular to the surface of the substrate as 0°, a material of the low refractive index layers of the antireflection film is silicon dioxide, a material of the high refractive index layers of the antireflection film is niobium oxide, a first layer of the antireflection film that is formed on the substrate is one of the low refractive index layers, and has an optical thickness between 0.05λ and 0.08λ, where λ=500 nm, a second layer of the antireflection film that is formed on the first layer is one of the high refractive index layers, and a third layer of the antireflection film that is formed on the second layer is one of the low refractive index layers, and has an optical thickness between 0.12λ and 0.17λ.