LARGE APERTURE LENS FOR THERMAL IMAGING DEVICE Russian patent published in 2010 - IPC G02B9/34 G02B13/14 

FIELD: physics.

SUBSTANCE: objective lens consists of two lenses. The first lens is a positive meniscus whose concave surface faces the image, the second is a biconcave lens, the third is a positive meniscus whose convex surface faces the image and the fourth is a positive meniscus whose concave surface faces the image. Total optical power of all lenses is not greater than 0.15 of the optical power of the entire objective lens. Total optical power of the first two lenses is negative and its absolute value is not less than 0.8 of the optical power of the entire objective lens.

EFFECT: design of a large aperture and high-resolution lens for the far infrared spectrum of 8-14 mcm, with diffraction-limited quality of the image, which enables operation with matrix pixels of up to 20 mcm, reduced thermal defocusing and improved manufacturability.

4 dwg, 3 tbl