APOCHROMATIC LENS Russian patent published in 2015 - IPC G02B9/12 G02B11/18 

FIELD: physics.

SUBSTANCE: lens comprises three components on the beam path. The first component is in the form of a positive meniscus, glued from a biconvex and biconcave lens and facing the image plane its concave side. The second component is in the form of a positive meniscus, glued from a first positive lens and a negative lens. The third component is negative and is glued from a biconvex lens and a biconcave lens. The refraction indices and average dispersion coefficients of the materials of the lenses satisfy relationships given in the claim. The lens can be supplemented with a beam-splitter prism placed between the third component and the image plane.

EFFECT: high light-gathering power while maintaining image quality by selecting a combination of glass and aberration correction, which reduces coordinate chromatism and correcting residual astigmatism.

2 cl, 5 dwg, 1 tbl