HIGH-APERTURE LENS WITH OFFSET PUPILS FOR INFRARED AREA OF SPECTRUM Russian patent published in 2010 - IPC G02B13/14 G02B9/60 

FIELD: optics.

SUBSTANCE: lens may be used in optical systems of infrared imagers. Lens comprises the first, second and third positive components arranged along travel of beams and including five lenses, and aperture diaphragm between the third component and plane of image. Between the first and second components there is cavity of intermediate image arranged. The first component comprises one meniscus, the second and third ones comprise two menisci each. Refracting surfaces of all menisci are arranged as spherical. Positive meniscus of the first component and the second positive meniscus of the third component are inverted with their concavity to plane of images. In the second component the first positive meniscus is inverted with its concavity to space of objects, and the second negative meniscus inverted by its concavity to space of images is tightly adjacent to it. Between optical forces of components and menisci, ratios given in formula of invention are realised between components and focus distance of lens.

EFFECT: improved manufacturability by exclusion of aspherical refracting surfaces and simultaneous increase of relative size of back focal section with preservation of aperture ratio, angular field in space of objects and high quality of image.

4 dwg, 2 tbl