FAST LENS FOR NEAR IR-SPECTRUM RANGE Russian patent published in 2008 - IPC G02B9/60 G02B11/30 G02B13/14 

FIELD: electro-optics.

SUBSTANCE: fast lens can be used in viewing devices provided with electro-optic converter or with other IR-receivers. Fast lens has five components disposed in series along beam path: single positive menisci turned with its convexity to object, single negative menisci turned with convexity to object; biconvex lens glued with biconcave lens, biconvex single lens and convex-flat single lens turned with its surface to image. The following conditions are met in fast lens: R₄= R₅, d₈=d₁₀, 1,2<R₆<f'<4,2, where R₂, R₅ and R₆ are radiuses of fourth, fifth and sixth optical surfaces along beam path; d₈ is thickness of the fourth component; d₁₀ is thickness of the fifth component; f' is focal length of whole fast lens.

EFFECT: better aperture; improved manufacturability; higher quality of image.

2 cl, 1 dwg