CATADIOPTRIC LENS FOR NEAR-INFRA-RED RADIATION SPECTRUM Russian patent published in 1997 - IPC

FIELD: optoelectron devices. SUBSTANCE: the catadioptric lens has the first collecting lens in the rays path, whose second surface in the central part has a mirror reflecting coating, diverging meniscus lens with the concavity facing the object, ring-shaped reflecting coating, second collecting lens cemented to the first surface of the diverging meniscus lens, and a light filter installed after the meniscus lens, the following relations should be satisfied: , where Φ_c- focal power of field aberrations compensator; Φ_cl - focal power of second collecting lens; Φ_ljp - focal power of catadioptric lens; d - distance between countermirror and second collecting lens. f′ - image-side focal distance of catadioptric lens. The first collecting lens may be made convex-concave, and the countermirror may be flat. EFFECT: improved quality. 2 cl, 1 dwg, 8 tbl