THREE-LENS CONDENSER Russian patent published in 2016 - IPC G02B19/00 G02B9/16 

FIELD: physics.

SUBSTANCE: condenser consists of three separate lenses and includes two identical plane-convex lenses, the first of which faces the object with the plane surface on the beam path, and the last faces the image with the plane surface. A second lens in the form of a negative meniscus is placed in between. The second lens has a radius of a convex optical surface equal in magnitude to the radius of curvature of the convex optical surface of the first lens, and faces the image plane with the convex surface.

EFFECT: larger linear field in the object space while maintaining high image quality.

1 dwg, 2 tbl