An infrared lens 1a includes first to third lenses L1 to L3 which are made of zinc sulfide and arranged in this order from an object side. Each of the first to third lenses L1 to L3 is configured as a positive meniscus lens of which convex surface is opposed to the object. The lenses L1 to L3 are formed...http://www.google.fr/patents/US8085465?utm_source=gb-gplus-shareBrevet US8085465 - Infrared lens, infrared camera, and night vision
