Abstract: A photoluminescent liquid-crystal display includes a liquid crystal (31) sandwiched between two transparent substrates (1, 21) for modulating input light, control electrodes (13, 23) for controlling the liquid crystal, and display output means incorporating a photoluminescent material (3) such as a phosphor for producing a visible image from the input light modulated by the liquid crystal. The phosphor is at the inner face (16) of the front substrate (1) but is sepraated from the liquid-crystal by a thin transparent auxiliary substrate (7) having a thickness of less than about 300 &mgr;m. This allows the phosphors to be close to the liquid-crystal layer (31), minimising crosstalk, without interfering with the electro-optic properties of the device.

Abstract: A liquid crystal display of the UV-phosphor type comprises a light source 1 for producing activation light at a predetermined narrow range of UV wavelengths, a collimator 3 for directing the activation light in parallel in a predetermined direction, a LC cell 5 formed from an array of pixels, a photoluminescent screen (7) on the cell arranged to emit a visible output when struck by the narrow-band excitation light passing through the cell, and a drive circuit for addressing the LC cell in a multiplexed manner. The direction of the light and the thickness of the cell are chosen to give the best contrast ratio for the liquid crystal. Such an effect is only possible when monochromatic, collimated light is used, which for a normal display is not practical.