PROJECTION LENS Russian patent published in 2013 - IPC G02B9/62 

FIELD: physics.

SUBSTANCE: lens has series-arranged first group of lenses, an aperture diaphragm and a second group of lenses. The first group of lenses has two positive menisci glued together and facing the object with their convex side. The first lens of the second group is negative, faces the object with its concave side and is glued from two menisci, the second of which is positive. The second lens of the second group is positive and its convex side faces the image. The third lens of the second group is biconcave and is glued from a biconcave lens and a positive meniscus. Between the second and third lenses of the second group there is a biconvex lens and a positive meniscus whose concave side faces the image. All radii of the lenses are spherical and the material of the lens is optical clear glass.

EFFECT: operation of the lens with objects lying at a finite distance, high illumination on the edge of the image field, providing the value and sign of distortion which is sufficient for correcting distortion of an X-ray image converter distortion, high manufacturability.

4 dwg