CATADIOPTRIC TELESCOPE Russian patent published in 2013 - IPC G02B17/08 

FIELD: physics.

SUBSTANCE: telescope has, in the beam path, a main concave spherical mirror, a compensating element having two separate lenses made of different types of glass with quasi-near dispersion coefficients in the visible spectrum, the first of which is in form of a negative quasi-focal meniscus whose concave surface faces the observed object, and the second is negative, has a mirror reflecting surface and is made from material with a smaller refraction index, and an afocal field aberration corrector consisting of two lenses and is placed in front of the focal plane of the telescope. The negative lens of the corrector which is first on the beam path is made from flint glass in form of a quasi-focal meniscus whose concave surface faces the image plane, and the second positive lens of the corrector is plane-convex, is made from crown glass and its convex spherical surfaces faces the image plane.

EFFECT: wider angular field of view of high-quality images.

3 dwg