A reflective cholesteric display that may be viewed under a wide range of ambient lighting conditions, ranging from complete darkness to bright sunlight. The display includes a chiral nematic liquid crystal material located between first and second substrates, an ambidextrous or bi-directional circular...http://www.google.com.tw/patents/US7009666?utm_source=gb-gplus-share專利 US7009666 - Back lit cholesteric liquid crystal display
