INFRARED CUT FILTER
An infrared cut filter is disclosed. This filter includes a transparent substrate and one or more infrared absorbing layers containing an infrared absorbing compound on at least one principal surface of the transparent substrate, wherein a transmittance at a wavelength of 1200 nm measured in a stack composed of the transparent substrate and the one or more infrared absorbing layers is 10% or less.
1 . An infrared cut filter comprising a transparent substrate and one or more infrared absorbing layers on at least one principal surface of the transparent substrate,
wherein the infrared absorbing layer is a layer containing an organic dye or an inorganic particle in a transparent resin or a layer composed of an inorganic particle, and
wherein a transmittance at a wavelength of 1200 nm measured in a stack composed of the transparent substrate and the one or more infrared absorbing layers is 10% or less.
2 . The infrared cut filter according to claim 1 ,
wherein the transparent substrate is a glass substrate.
3 . The infrared cut filter according to claim 2 ,
wherein the glass substrate is a copper-containing glass substrate using phosphate glass or fluorophosphate glass as a base material and containing copper in the base material.
4 . The infrared cut filter according to claim 1 ,
wherein the organic dye is at least one selected from a group consisting of a diimonium-based compound, a squarylium-based compound, a dithiolene metal complex-based compound, a mercaptophenol metal complex-based compound, a mercaptonaphthol metal complex-based compound, and an aminium-based compound.
5 . The infrared cut filter according to claim 4 ,
wherein the organic dye comprises a diimonium-based compound.
6 . The infrared cut filter according to claim 1 ,
wherein the inorganic particle is at least one selected from a group consisting of a sodium tungstate particle, a potassium tungstate particle, a rubidium tungstate particle, and a cesium tungstate particle.
7 . The infrared cut filter according to claim 6 ,
wherein the inorganic particle is a cesium tungstate particle.
8 . The infrared cut filter according to claim 1 ,
wherein the transparent resin comprises a polyester resin.
9 . The infrared cut filter according to claim 8 ,
wherein the polyester resin contains 1 to 10 mol % of structural units derived from an aliphatic dicarboxylic acid.
10 . The infrared cut filter according to claim 1 , further comprising
a dielectric multilayered film formed on at least one principal surface of the transparent substrate.
11 . The infrared cut filter according to claim 1 , further comprising
one or more near-infrared absorbing layers containing a near-infrared absorbing compound, on at least one principal surface of the transparent substrate.
12 . The infrared cut filter according to claim 1 , further comprising
an anti-reflection film constituting an uppermost surface on at least one principal surface of the transparent substrate.