LED-based high efficiency illumination systems for use in projection systems

摘要

The dilemma encountered in most projection systems of having the etendue of the LED-based light source used often being much larger than the etendue of the imager used, causes such systems to have poor throughput efficiency. The etendue folding illumination systems of this invention being comprised of at least one folded collimator/concentrator having coupled into its input aperture an LED-based light source and having an output aperture characteristics that match the target etendue, overcome this dilemma by folding the light source etendue to match the target etendue of the projection system imager while efficiently conserving the flux generated by the light source.