APOCHROMATIC LENS (VERSIONS) Russian patent published in 2011 - IPC G02B9/12 

FIELD: physics.

SUBSTANCE: lens consists of three components. The first component is a single biconvex lens (1). The second consists of a biconvex (2) and a biconcave (3) lens and a converging-meniscus lens (4). The third consists of a biconvex (5) and a biconcave (6) lens. All the lenses are made from two types of common optical glass. In the first version, refraction indices 1.45<n₁<1.55; 1.65<n₂<1.75, and dispersion coefficients 60<γ₁<95; 20<γ₂<30 or 40<γ₂<50. In the second version, refraction indices and dispersion coefficients satisfy the condition: 1.43<n₁<1.45 or 1.55<n₁<1.65; 1.75<n₂<2.2; 60<γ₁<95; 20<γ₂<30 or 40<γ₂<50.

EFFECT: higher image quality.

2 cl, 9 dwg