DOUBLE LENS Russian patent published in 2021 - IPC G02B9/10 

FIELD: visual optical systems.

SUBSTANCE: lens can be used in both visual optical systems and infrared systems. The lens consists of two lenses. The first lens is made in the form of a biconvex, and the second lens is in the form of a negative meniscus, convex facing the image. There are the following ratios: |R₁|=|R₃|; |R₁|<|R₂|; 0,4<|R₁| /f≤0,52; 0,58≤|R₂| /f≤2; 9≤|R₄| /f≤300 where R₁, R₂, R₃, R₄ are the radii of the first, second, third and fourth optical surfaces along the beams; f is the focal length of the entire lens.

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

1 cl, 1 dwg, 2 tbl