TWO-LENS OBJECTIVE Russian patent published in 2017 - IPC G02B9/02 G02B3/00 

FIELD: physics.

SUBSTANCE: invention can be used both in devices of a visible range of a spectrum, and in IR-systems. The two-lens objective consists of the glued negative meniscus, which is located along the rays, facing with convexity to the object, and a biconvex lens. The radii of the outer spherical optical surfaces of the negative meniscus and biconvex lens are equal in absolute value. There is a plane-parallel plate behind the biconvex lens, which can also be made in the form of a light filter.

EFFECT: increased relative aperture and increased angular field in object space at high technology and high image quality.

1 dwg, 1 tbl