TELESCOPIC SYSTEM FOR NEAR INFRARED LIGHT Russian patent published in 1998 - IPC

FIELD: extensions for night-vision equipment. SUBSTANCE: device has two members. First member is designed as biconvex lens and negative meniscus which concavity is directed to article. Second member is designed as biconcave lens. Device conforms to conditions $$$, where $$$ are focal lengths of first and second lenses of first and second members, $$$ are curvature radiuses of lenses of first and second members, $$$ is focal length of first member. EFFECT: increased functional capabilities. 2 dwg, 1 tbl