Patent ID: 7733579

Claim:
An image pickup system comprising one or more optical elements, wherein an infrared cut coating in which a maximum value of reflectance at a wavelength λ of 800 to 1200 nm is 30% or more, is formed on at least two optical surfaces of the optical elements, wherein the image pickup system has a layered structure in which when a design wavelength is λ 0 , a refractive index of a low refractive index layer is n L , a thickness of the low refractive index layer is d L , a refractive index of a high refractive index layer is n H , a thickness of the high refractive index layer is d H , wherein the layered structure includes at least three layers, each layer of the infrared cut coating being sequentially numbered as at least a first layer, a second layer, and a third layer from an air side, and wherein the infrared cut coating satisfies following conditions: 800 nm≦λ 0 ≦1200 nm, 1.3≦n L ≦1.6, 1.8≦n H ≦2.3, the first layer satisfies 0.08λ 0 ≦n L d L ≦0.17λ 0 , the second layer satisfies 0.2λ 0 ≦n H d H ≦0.3λ 0 , and the third layer satisfies 0.2λ 0 ≦n L d L ≦0.3λ 0 .