An illumination system includes a light source, an ellipsoidal mirror for converging light emitted from the light source, a fly's eye lens unit disposed at a converging point of the ellipsoidal mirror, a collimation lens for collimating light rays exited from the fly eye lens unit, and an object disposed...http://www.google.es/patents/US4884869?utm_source=gb-gplus-sharePatente US4884869 - Fly's eye lens unit for illumination system
