LENS WITH A SPECTRO-SPLITTING UNIT Russian patent published in 2020 - IPC G02B9/62 

FIELD: optics.

SUBSTANCE: lens has four components. First component includes three elements, the first element is a biconvex lens, the more convex surface faces the object space, the second component is a negative meniscus whose convex surface faces the object space, and the third one is a positive meniscus whose convex surface faces the object space. Second component is a biconvex lens which faces the space of objects with a more gently sloping surface. Third component is a biconcave lens with a more concave surface facing the image space. Fourth component is a biconvex lens, wherein its first radius is equal to its second radius. Spectro-splitting unit is arranged between the third and fourth components. Distance between first and second components is not less than 0.241ƒ'. First and third elements of the first component of the refractive indices of the glass lens does not exceed 1.434, and the relation n₁=n₃, where n - the refractive indices of the elements of the first component, respectively.

EFFECT: increasing focal length while maintaining its short length from its first surface to the image plane and enabling simultaneous recording of images on the CCD matrix and photodetector while maintaining high image quality.

1 cl, 5 dwg, 3 tbl