APOCHROMATIC LENS Russian patent published in 2011 - IPC G02B9/14 

FIELD: physics.

SUBSTANCE: proposed lens consists of three components arranged along ray path, first and third component being positive. First component represents meniscus lens with concave side facing image plane. Second component represents negative meniscus lens made up of biconcave and biconvex lenses glued together. Third component is made up of two approximate lenses first being biconvex and second being negative meniscus lens with concave side facing image plane. Refracting surface of lenses are spherical. Lenses are made from two optical glass grades. Lens material refractivity and mean dispersion factor obey the following relation: 1.82<n₁<1.9; 1.57<n₂<1.65; 21<v₁<30; 60<v₂<67.

EFFECT: reduced amount of lenses, higher relative aperture and image quality.

5 dwg