INFRARED OPTICAL ASSEMBLY AND INFRARED IMAGE CAPTURE DEVICE

摘要

[Object] To provide an infrared optical system and an infrared image capturing apparatus having good optical properties in a far infrared ray area while costs are reduced. [Solving Means] There is provided an infrared optical system includes a light collecting lens having a curved light collecting surface for collecting infrared light incident from an object side, the lens being made of resin having a stepped shape being gradually deeper from periphery to center; and an optical path length correction element for correcting a difference in an optical path length produced by the stepped shape of the light collecting lens. The above-described stepped shape is provided to allow the lens to be thinner than the lens having the plano-convex shape. In other words, the infrared transmittance of the optical system is improved. In addition, the optical path length correction element can correct a difference in an optical path length produced by the stepped shape of the light collecting lens.