Abstract: A multiplex control active matrix display screen including a first transparent substrate supporting an array of electrodes controlled by an array of transistors. Each transistor has two control gates. The second gates are interconnected along an addressing row or column. The rows and columns are interconnected in groups of N. The transistors of a column or row are then controlled by multiplexed three control signals.

Abstract: A transflective optical filter comprises a single transparent or transluscent substrate; a colored slice made up of a plurality of layers, each corresponding to one color out of at least two colors; a light diffusing layer; and an opaque mask on which the marks to be displayed in color are represented by transparent zones, the colored slice and the mask consisting of photographic emulsions. A method for making that filter involves multiple exposures of a same film having a multi-colored "slice" and a monochrome photosensitive layer.

Abstract: A color matrix display unit which has a screen having at least three sets pixels, all pixels in a same one of the three sets being of the same color among red, blue and green and all said pixels of a same one of said sets being distributed in a matrix arrangement comprising rows and columns. A plurality of column conductors each simultaneously addresses all pixels in a same column. A plurality of row conductors each simultaneously addresses all pixels in a same line. Each column conductor allocated to red or blue pixels addresses an overall pixel area that is about double the overall pixel area addressed by one of the column conductors allocated to a green pixel. A drive circuit connected to the column conductors addresses the green pixels with a time or space repetition period which is half the period for red and green pixels.

Abstract: The device comprises a thin layer (10) of liquid crystals disposed between a plane backing electrode and control electrodes each co-operating with the backing electrode to define a capacitor and a picture element such that each pixel corresponds to a row and to a column, each control electrode being connected to a control element such as a thin-film transistor enabling it either to be raised to the potential of a conductor which is common to all of the pixels in the column to which it belongs, or else to isolate it therefrom and cause it to take up a floating potential. The backing electrode is made up of two fractions (20.sub.1, 20.sub.2) provided with means enabling, them to be taken to different potentials that are inverted on each frame or multiple of the frame frequency, and in which successive columns (or successive groups of a few columns each) of control-electrodes co-operate with different ones of the fractions.