Abstract: A device for addressing a matrix screen such as a screen of the LCD or plasma type having a memory stage receiving, via a demultiplexing stage a plurality of sequences of digital data representing the previously digitized luminance video signals, and delivering the luminance video signals to a multiplexing stage designed to select a sequence of digital data corresponding to a given combination of subpixels from amongst the plurality of sequences of digital data previously stored in the memory stage.

Abstract: Disclosed is a method for the addressing of each column of a matrix type LCD panel consisting in the production of a pulse to control a driver transistor of said column, said pulse having a duration determined by the value of the video signal sample at input, said pulse acting on the conduction state of said transistor to connect said column to a supply terminal where a voltage gradient develops. According to the method two pulse durations, the sum of which is predetermined, are alternated and, in order that a given value of a video signal sample may produce the same optical effect from one period to the next one, differentiated excitation voltages are applied to at least one of the electrodes sandwiching the liquid crystal layer, namely said column and its counter-electrode. Application notably to active matrix LCD panels.

Abstract: The present invention is a video drive apparatus of the two ramp type which includes facility to selectively adjust the brightness and/or the contrast of an image reproduced on a display device. In this apparatus, at least one of the ramp signals is generated digitally by for example a counter. Provision is made to change the counting rate of such counter which effects a change in display contrast. Provision is also made to selectively change the phase of the ramp signal applied to the second stage relative to the start of respective pulses of the PWM signal thereby effecting brightness changes in the reproduced image.

Abstract: An actuation circuit for a liquid crystal display includes a plurality of pixel elements constructed in the form of a matrix of columns and rows and a plurality of column capacitors connected to respective columns of the liquid crystal display that can be charged to store a signal to be displayed. The activation circuit comprises a number of blocks which each comprise a separate group of the columns forming the matrix of pixel elements, a corresponding number of column capacitors, and a plurality of data lines. The individual data lines receive respective signals and are connected to the column capacitors. A switch device is connected to each respective block for successively switching between the number of blocks.