LIQUID CRYSTAL DEVICE

1298257 Matrix displays RCA CORPORATION 31 July 1970 [25 Aug 1969] 37159/70 Heading G5C A display device comprises a cell containing transparent nematic liquid crystals 17 between transparent plates 11, 12, transparent electrodes 15, 16 associated with each plate and a plurality of planar elements 46 disposed over and inclined to one of the plates to prevent direct light passing. Parallel tin oxide strip electrodes on each plate are arranged to form a crossed array. Spacers are disposed between and bonded to the plates 11, 12. The elements 46 comprise opaque dull black vanes embedded in a transparent plastics material 44. Applying A.C., D.C. or pulsed D.C. potential between a pair of opposed electrodes causes local turbulence in the liquid, e.g. anislidene-p-aminophenylacetate which produces a forward light scattering state and a white appearance compared to the black background of the vanes visible through unenergized areas of the liquid. The degree of scattering is directly proportional to the potential above a threshold value. The electrodes may be sequentially energized or a number simultaneously energized to produce a fixed display.