DOUBLET-OBJECTIVE LENS Russian patent published in 2021 - IPC G02B9/10 

FIELD: optical equipment.

SUBSTANCE: lens can be used in both visual and IR systems. A doublet-objective lens consists of biconvex and biconcave lenses. The radius of the first optical surface of the biconvex lens along the course of the rays is equal in absolute value to the radius of the first optical surface of the biconcave lens along the course of the rays. The radius of the first optical surface of the biconvex lens along the course of the rays is modulo less than the radius of curvature of its second optical surface. There are relations: 0.48≤|R₁|/f'≤0.54; 0.5253≤|R₂|/f'≤0.59; 40≤|R₄|/f'≤127, where R₁, R₂, R₄ are the radii of the first, second and fourth optical surfaces along the course of the rays; f' is the focal length of the entire lens.

EFFECT: increase in the relative aperture and the angular field in the space of objects with high image quality.

1 cl, 1 dwg, 2 tbl