US Patent 8691351 Antireflection film, polarizing plate and image display device

An antireflection film includes, in a following order, a transparent substrate film; a medium refractive index layer; a high refractive index layer; and a low refractive index layer, wherein the medium refractive index layer is (A) a medium refractive index layer having a refractive index of 1.60 to 1.64 at a wavelength of 550 nm and a thickness of 55.0 to 65.0 nm, the high refractive index layer is (B) a high refractive index layer having a refractive index of 1.70 to 1.74 at a wavelength of 550 nm and a thickness of 105.0 to 115.0 nm, and the low refractive index layer is (C) a low refractive index layer having a refractive index of 1.32 to 1.37 at a wavelength of 550 nm and a thickness of 85.0 to 95.0 nm.