OBJECTIVE LENS FOR CLOSER INFRARED SPECTRUM Russian patent published in 2008 - IPC G02B9/62 G02B13/14 

FIELD: physics.

SUBSTANCE: objective lens incorporates, in the beam course, a single positive lens, a compound lens with a positive and a negative meniscus turned with their concave sides to the image, a single negative lens, a convexo-convex lens, and a single convexo-convex lens. The single positive lens is a meniscus turned with its convex side to an object, the single negative lens is concavo-concave, and the convexo-convex lens is single. Air gap between the compound lens menisci can vary from 0 to 0.03 mm.

EFFECT: improved image quality within the whole field for a small objective lens length and large rear top.

4 dwg