Low Power Laser Addressed Liquid Crystal Projection Display Device
Original Publication Date: 1981-Aug-01
Included in the Prior Art Database: 2005-Feb-12
Laser-beam-addressed, thermally activated liquid crystal cells have been used for reflective projection displays of high information content. The liquid crystal is sandwiched between two pieces of glass: the front viewing window and the rear writing window. The cell configuration is shown in the drawing, with the proposed layer included. In operation, the liquid crystal cell is thermally biased a few degrees centigrade below the smectic A to nematic transition temperature (T(AN)). In the quiescent state, liquid crystal is transparent. The laser beam is used to selectively heat a portion of liquid crystal to raise its temperature beyond T(AN). After the removal of the laser beam, the liquid crystal is cooled down and transformed into a scattering state.