MIRROR LENS Russian patent published in 2018 - IPC G02B17/06 

FIELD: physics.

SUBSTANCE: mirror lens consists of three mirrors installed in the course of the mirror beam. The first mirror is made in the form of an aspheric off-axis fragment of a concave positive mirror turned by the concavity to the plane of objects. The second mirror - in the form of a fragment of the aspherical convex negative mirror turned by the convexity to the first mirror. The third mirror - in the form of a fragment of the aspherical concave positive mirror turned by the concavity to the second mirror. In the meridian section, the first mirror is lower than the optical axis, and the second and the third mirrors - higher than the optical axis. The focus of the first mirror is located in front of the second mirror.

EFFECT: creation of a compact lens with a diffraction image quality in a wide spectral range and rational layout: no shielding, not decentred at the field corner.

2 cl, 3 dwg, 1 tbl