Abstract: Ferroelectric liquid crystal screen with opacified electrodes in the non-switchable area of the screen and processes for obtaining spacers and treating said screen.On each part of each row or column electrode of the screen, facing a gap separating two column or row electrodes is arranged an element (40,50) preventing the passage through the screen of light reaching the latter in the direction of the element. The elements located on the row electrodes (32) or those located on the column electrodes (34) also permit the spacing, without electrical connection, of the screen plates and the localization of the zigzag defects which the liquid crystal may have, in or in the vicinity of the non-switchable area of the screen. The screen is appropriately heated and an alternating voltage is applied between the electrodes in order to localize the zigzag defects of the liquid crystal in the vicinity of the spacing elements.

Abstract: The invention relates to a polychrome screen comprising alternating regions (40A, 40B) of a first (A) and a second (B) dichroic display materials placed between first and second insulating walls (31, 33) and alternating regions (42B, 42C) of a second (B) and a third (C) dichroic display materials placed between the second and third insulating walls (33, 35); each region of the first material of the first layer being superimposed both on a region of the second material of the second layer and part of a region of the third material of the second layer and each region of the second material of the first layer is superimposed on the other part of the region of the third material of the second layer. The present invention more particularly applies to polychrome display cells with liquid crystals, such as those of the nematic or ferroelectric type, using both a multiplexed and non-multiplexed display mode.

Abstract: Bistable ferroelectric smectic liquid crystal display device.This device comprises a tight cell inserted between two polarizers formed from two glass walls, each provided with a display-appropriate electrode connected to an electric power supply for applying an electric field for controlling the liquid crystal to a chiral ferroelectric smectic liquid crystal film inserted between the electrodes. To obtain bistability and storage of the liquid crystal, one of the walls is covered with a material constituted by a stack of a silica layer, a polyimide layer, an optionally rubbed organosilane film in contact with the liquid crystal and the other wall is provided with a silica film covered with a Nylon film.