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.