An illumination engine for a projection display using light emitting diodes (LEDs) that includes a reflector having a first and second focal points, a source of electro-luminescence located proximate to the first focal point to emit rays of radiation in a first range of wavelengths that reflect from...http://www.google.de/patents/US6926435?utm_source=gb-gplus-sharePatent US6926435 - Led illumination engine using a reflector
