Refractive-reflective optical system with heavy caliber, large view field and small focal ratio

Abstract

The invention relates to a telescope system with heavy caliber, large view field and small focal ratio. The telescope system comprises a heavy-caliber Cassegrain system at the front end, and the heavy-caliber Cassegrain system comprises a paraboloidal primary mirror (1) the caliber of which exceeds 1 meter and a hyperboloidal secondary mirror (2); by adopting an inclined plane mirror (3), the optical path is led to the horizontal optical axis Y vertical to a primary optical axis Z which comprises the primary mirror and the secondary mirror, and the plane mirror (3) is connected with a focal reducing system at the Smith-resistant focal position, wherein the focal reducing system comprises four groups of lenses, that is to say, a field lens group (I) comprising only one positive-focal-powerlens, a second lens group (II) comprising four lenses, a positive-focal-power third lens group (III) comprising two lenses, and a positive-focal-power fourth lens group (IV) comprising three lenses. Especially, a diaphragm (9) is arranged between the second lens group and the third lens group, and the diaphragm (9) and the primary mirror conjugate and can be used for dimming.

Description

technical field [0001] The invention relates to the field of optical systems, in particular to an optical system with a large diameter, a large field of view and a small focal ratio, which can be applied to ground-based astronomical telescopes. Background technique [0002] Astronomical telescopes with large aperture, large field of view and small focal ratio are of great significance in astronomical observation, because large aperture means stronger light-gathering ability, large field of view means larger single-frame observation range, and small focal ratio can detect more Weak magnitude. Traditional large-aperture astronomical telescopes must use reflective primary mirrors, and the characteristics of reflective optical systems limit the enlargement of the field of view. The classic Cassegrain system (Cassegrain), because the image plane must be pulled out behind the main mirror, so the focal length is longer, and the focal ratio is generally around f / 7~f / 15. The primar...

AI Technical Summary

Problems solved by technology

Although the R-C telescope system has more advantages than the classic Cassegrain system, the primary mirror of the R-C system must be a hyperboloid, and the processing and inspection are much more difficult than the parabolic primary mirror of the Cassegrain system. At the same time, the focal length of the R-C system than can not be designed too small

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