CATADIOPTRIC TELESCOPE Russian patent published in 1999 - IPC

FIELD: astronomic instruments, in particular, for observation of Sun, Moon and planets. SUBSTANCE: optical system of device consists of main concave spherical mirror and correction element which are arranged in series. Correction element has two single lenses, first of which is designed as negative quasi-afocal meniscus which concave side is directed towards subject of observation. Second lens of correction element is negative and has mirror reflecting surface. Lenses of correction element are made from different glass types, which dispersion rates in visible spectrum are close. First lens is made from glass with large refraction index. EFFECT: increased light- gathering power, increased spectral range. 2 cl, 5 dwg, 2 tbl