LENS SYSTEM FOR SHORTWAVE INFRARED SPECTRUM Russian patent published in 2023 - IPC G02B9/62 G02B13/14 

FIELD: lens systems.

SUBSTANCE: lens system can be used as a collimator lens system as part of test equipment for simulating background-target environment based on micromirror arrays. The lens system consists of a first biconvex lens, a second negative concave-convex lens, a third negative convex-concave aspherical lens, a fourth biconvex lens, a fifth positive convex-concave lens, and a sixth negative convex-concave lens. The aperture diaphragm is located in front of the first lens. The condition is fulfilled: n₁=n₄=n₅<n₃<n₂=n₆, where n₁, n₂, n₃, n₄, n₅, n₆ are the refractive indices of the materials of the first, second, third, fourth, fifth and sixth lenses, respectively.

EFFECT: improved performance of the lens due to improved image quality over the entire field of view.

1 cl, 3 dwg, 2 tbl