Primary mirror for celesial (astronomical) telescopes

摘要

The prior art is reflecting (mirror, catoptric) telescopes having a fixed focal point, which are produced from ground glass elements and provided with a reflective layer. The object of the invention is to reduce the production costs for a reflecting telescope by using a rotating liquid mirror, and to undertake a shift in focal point by varying the rotational speed. It is known that a precise paraboloid of rotation is formed by rotating a liquid. According to the invention, the object is achieved when the primary mirror (5, Fig. 1) consists of a rotating liquid. The light beams (1) are projected via the planar auxiliary mirrors (2 and 4) onto the rotating primary mirror (5) which consists of a round vessel with liquid. The focused light beams are reflected to the focal point where a plane (flat) mirror (6) leads the light beams to the eye (8) of the observer via lenses (7). The change in focal point can be undertaken by a motor (9) whose rotational speed can be adjusted and which drives the liquid mirror (5) via V-belts (10), a bearing (11) and a shaft (12). <IMAGE>