HIGH-APERTURE LENS FOR NEAR IR SPECTRAL RANGE Russian patent published in 2020 - IPC G02B13/14 G02B9/06 

FIELD: optics; data processing.

SUBSTANCE: lens can be used in digital sight-seeing devices with CCD or CMOS matrices in day and night conditions. Lens comprises aperture diaphragm and two components, first of which is glued from biconvex and biconcave lenses, second component is positive meniscus, convexed to object, first surface of which is aspherical. Aperture diaphragm is located on the first surface of the first component. Following ratios are met: 0.8≤d₄/F_L≤1.2, 0.4≤r₅/r₆≤0.9, 1.65≤n₃≤1.75, where F_L focal length of the lens; d₄ air gap between first and second components; n₃ is second component lens refractive index; r₅ is radius of curvature at apex of second component lens aspherical surface; r₆ is the radius of curvature of the second surface of the second component lens.

EFFECT: high luminosity to 1:1,4 with spectral range extension to Δλ=(0,6÷1) mcm, with preservation of image quality without vignetting of inclined beams.

1 cl, 1 dwg, 1 tbl