Liquid crystal display device having extended service life

Claim 1

A field-effect liquid crystal display device, comprising a pair of opposed glass plates, at least one transparent electrode on the inner surface of each of said glass plates, said transparent electrodes being connectable to an external source of voltage, nematic liquid crystals of positive dielectric anisotropy between said glass plates, said nematic liquid crystals being thoroughly dry and free of volatiles, an insulating spacer of a material deformable at elevated temperature between said glass places and conforming exactly to said inner surfaces of said glass plates, a sealant which is free of volatiles and is essentially impermeable to water vapor between said glass plates and exterior to said spacer, a film of a synthetic resin covering that portion of the inner surface of each glass plate interior to said spacer, said films being unidirectionally grooved and thereby oriented, said films being thick enough to be grooved and thin enough to interfere only negligibly with transmission of visible light therethrough, said glass plates being mounted opposite each other so that the directions of the grooves on said opposed plates are at right angles to each other and a pair of polarizer plates sandwiching said glass plates, the deformation temperature of said spacer material being lower than the melting and decomposition temperatures of said synthetic resin, and said spacer and the inner surfaces of said glass plates being essentially free of such organic compounds, water and water-of-composition of said glass plates as are volatile at temperatures at least as high as the deformation temperature of said spacer and below that at which said synthetic resin flows or is thermally degraded.