United States Patent Number: 5,928,801, June 27, 1999, pages 1-7. Also available from the United States Patent and Trademark Office. Website: http://www.uspto.gov.
An illumination system has an active layer which includes an electroluminescent material, the active layer being located between an optically transparent electrode layer and a reflective electrode layer. A reflective polarizer is present at a side of the transparent electrode layer facing away from the active layer. A sub-beam incident on the polarizer and having an unwanted polarization is reflected back to the active layer, where it is again partially depolarized to recover a component having the desired state of polarization. The invention also relates to a flat-panel picture display device which includes such an illumination system.
Electrical and Computer Engineering