LARGE-APERTURE LENS Russian patent published in 2011 - IPC G02B9/34 G02B13/14 

FIELD: physics.

SUBSTANCE: lens has four components lying in series on an optical axis. The first component is a single plane-convex lens whose flat surfaces faces the image space. The second component is glued from a biconvex lens, which faces the first component with its surface with the smaller radius of curvature, and a biconcave lens which faces the image space with its surface with the smaller radius of curvature. The third component is glued from a negative meniscus and a biconvex lens which faces the image space with its surface with the greater radius of curvature. The fourth component is a biconcave lens which faces the image space with its surface with the greater radius of curvature. The aperture diaphragm lies on the surface of the second component, facing the image space.

EFFECT: high aperture ratio with simultaneous simplification of the design and wider range of nominal size of the CCD matrix used.

5 dwg, 4 tbl