CATADIOPTRIC LENS ( VARIANTS ) Russian patent published in 2003 - IPC

FIELD: optics. SUBSTANCE: catadioptric lens according to each of two variants has first component coming in the form of plano-convex lens facing object with convexity, second component which is correction optical unit, includes several lenses last of which is made in the form of positive meniscus with optical power exceeding optical power of lens as whole and faces image with concavity, in the rest of lenses at least is manufactured in the form of meniscus, third component is fabricated in the form of concave mirror with hole in central zone and faces object with concavity. In compliance with first variant in central zone of convex surface of first component there is made flat secondary mirror and central zone of its second surface is concave facing image with concavity. According to second variant first lens of second component is plano-concave and faces object with concavity, secondary mirror being made on its flat surface. EFFECT: enlarged input aperture with high relative aperture, diminished mass and size characteristics, reduced radiation loss due to vignetting and screening of central zone. 8 cl, 8 dwg, 3 tbl