An illumination system includes a light mixing system for mixing light from a light source and emitting the mixed light, a multi-beam producing system for wavefront dividing the light from the light mixing system and for producing plural light beams, an imaging system for forming an image of a light...http://www.google.es/patents/US6259512?utm_source=gb-gplus-sharePatente US6259512 - Illumination system and exposure apparatus having the same
Illumination system and exposure apparatus having the same
