ELECTRON BEAM ADDRESSED LIQUID CRYSTAL LIGHT VALVE AND METHOD FOR CONSTRUCTION THEREOF

ELECTRON BEAM ADDRESSED LIQUID CRYSTAL LIGHT VALVE AND METHOD FOR CONSTRUCTION THEREOF An electron beam addressed liquid crystal light valve and method for construction. A twisted nematic liquid crystal cell comprises nematic liquid crystal material sandwiched between a transparent faceplate having a transparent electrode, and a transparent, dielectric target plate. A writing gun directs electrons at the target plate for writing thereon, a flood gun directs a cloud of electrons at the target for restoring the potential thereof, and a collector adjacent the target collects secondary emission and free flood gun electrons, the writing gun, flood gun, and collector being disposed outside a field of view through the cell. Collector potential is slightly less than that required to produce a target secondary emission ratio of 1 from flood gun electrons. A projection system utilizes polarizing material disposed in front of and behind the cell, and an optical system for directing light through the cell and polarizing materials. The cell is constructed by coating one side of a glass faceplate with a transparent electrode and forming alignment surfaces on the electrode and target plate. An inlet and an outlet through the faceplate are provided, the outlet being connected to a collection chamber. The target plate is placed over the transparent electrode, separated from the electrode by a spacer. The space within and surrounding the assembly is evacuated, after which thoroughly degassed liquid crystal material is forced by pressure through the inlet until the cell is entirely filled, at which point the inlet is sealed off. Thereafter, pressure on the outside of the target plate is increased until the target plate is substantially parallel to the faceplate, at which time the outlet tube is pinched off.