Jenoptik Jena G.m.b.h.

Klaus-Dieter Scharf

Ludwig Meier

Gebhard Kuhn

Gebhard Kuehn

Juergen Pudenz

An improved projector for projecting fixed stars in planetaria increases the brightness and the brilliance of the projected sky by using fiber optical light guides. The device comprises at least one light source, one condenser, one star plate or templates and one lens, which projects the star plate template on the planetarium dome. A fiber optical light guide cable, the light-entry end of which faces the condenser and which consists of fiber optical light guides or fiber optical light guide bundles, is provided between the condenser and the associated star plate or template. The other end of the fiber optical light guide cable is split up into fiber optical light guides and/or fiber optical light guide bundles, the light-emergence ends of which are assigned to the locations on the star plate or template which are to be illuminated.

Projector for projecting fixed star

This invention relates to an optical system for lantern slide projection, especially for star projectors in planetariums, with the aim of increasing the available light for the projection. The development consists in attaining an increase in brightness and brilliance of the image as well as a reduction in heat generation in the apparatus, through the application of resonator principles. The optical system comprises light sources, condensing lenses which reproduce the lamp filament, and the objective which reproduces the original. A resonator of high transparency which has highly reflective and/or totally reflective boundary surfaces is provided between condensing lens and objective. The boundary surface facing the condensing lens has a light-entrance opening comprising the lamp filament or the image of the lamp filament. The boundary surface lying opposite to that area preferably comprises the original to be projected. The resonator is formed as a glass or hollow body with circular, elliptical or multi-faceted cross-section or as a polyhedron, hollow polyhedron or ball.

Growing community of inventors

Jena-Lobeda, Germany

Klaus-Dieter Scharf