Patent ID: 7929204
Filing Date: 2011-04-19
Classification: G02B

Abstract:
1. An infrared cut filter comprising: a substrate; a first membrane group formed on the substrate, the first membrane group comprising a plurality of first combined membranes, each first combined membrane including a high-refractive index membrane having an optical thickness 1.2 times λ/4 and a low-refractive index membrane having an optical thickness 0.6 times λ/8 laminated in an alternating fashion; a second membrane group formed on the first membrane group, the second membrane group comprising a plurality of second combined membranes, each second combined membrane including a high-refractive index membrane having an optical thickness 1.1 times λ/4 and a low-refractive index membrane having an optical thickness 1.1 times λ/8 laminated in an alternating fashion; and a third membrane group formed on the second membrane group, the third membrane group comprising a plurality of third combined membranes, each third combined membrane including a high-refractive index membrane having an optical thickness 1.3 times λ/4 and a low-refractive index membrane having an optical thickness 1.3 times λ/8 laminated in an alternating fashion; wherein λ is a design wavelength of the infrared cut filter.