Abstract: Matrix screen, its production process and matrix display means with several tones, controlled on an all or nothing basis and incorporating said screen. The screen has electroluminescent zones distributed in matrix-like manner and placed between crossing row electrodes and column electrodes, each row electrode being formed from m first parallel conductive strips of different widths and each column electrode being formed from n second parallel conductive strips of different widths, m and n being positive integers, whereof at least one is 2. The electroluminescent zones are defined by the intersection of the first and second conductive strips. Application to half-tone display using electrical addressing circuits operating on an all or nothing basis.

Abstract: An electroluminescent matrix screen comprising nm light emitting cells disposed in the form of a matrix of n lines and m columns. Each cell (c.sub.e) is constituted by a two line by two column submatrix having four light emitting elements (el.sub.1 to el.sub.4) selected from three different base colors, such that each cell (c.sub.e) includes two elements (el.sub.1 to el.sub.4) which emit light of the same color. In addition, the areas of the various elements are chosen so that each cell provides, overall, three sources of different colored light having similar luminance. The invention also provides a method of manufacturing a trichromatic electroluminescent matrix screen.

Abstract: A flat electroluminescent screen comprising a transparent substrate on which are successively deposited a first group of parallel electrodes, said electrodes being transparent, a layer constituted by an electroluminescent material inserted between two dielectric layers and a second group of parallel electrodes, the two groups of electrodes intersecting and defining in the electroluminescent layer a plurality of optical emitters arranged in matrix form, said flat screen also comprising a control circuit for the first electrodes, a control circuit for the second electrodes and a protective counter-plate sealed on said substrate by a sealing band. On its inner face, the counter-plate carries at least one counter-electrode and means are provided so that each counter-electrode is electrically connected to the two ends of an electrode of the substrate.