Field illumination device for projection system has parabolic reflector enclosing light source and counter-reflector lying along common optical axis with its primary focus at secondary focus of parabolic reflector

摘要

The field illumination device has a light source (2) enclosed by a parabolic reflector (1) and at least one counter-reflector (3) positioned on a common optical axis (4), for reflecting the light beams (9) from the light source which do not pass through the secondary focus (F1s) of the parabolic reflector back towards the latter, for reflection in the direction of the secondary focus. The reflected light beams are coupled with an optical system (5) positioned at the secondary focus for providing the illuminated field, passing through a concentric opening (6) in the counter-reflector, the primary focus (F3p) of which coincides with the secondary focus of the parabolic reflector.