INFRARED LENS, INFRARED CAMERA AND NIGHT VISION

摘要

Infrared lens (1a) comprising, arranged in sequence from the object side, first to third lenses (L1 to L3) of zinc sulfide, the first to third lenses (L1 to L3) each being a positive meniscus lens whose convex surface is on the object side. The first to third lenses (L1 to L3) are formed by hot compression molding of zinc sulfide raw material powder using a lens-shaped die. The concave surface (image side surface) of the first lens (L1) is a diffractive surface.