A display device comprising at least one substrate, a first and a second electrode, a display medium and an optically active layer, wherein said optically active layer comprises a polarizer and is arranged between said substrate and said display medium, and wherein said substrate is made of a birefringent...http://www.google.com.au/patents/US20080043329?utm_source=gb-gplus-sharePatent US20080043329 - Display Device With Birefringent Substrate
