Nemoptic

France Brevets

Jean Denis Laffitte

Philippe Martinot-Lagarde

Stéphane Joly

A method for the control of a liquid crystal display that includes a matrix of pixels arranged in crossed lines and columns. A switching of state of the liquid crystal molecules, is controlled by application of an electrical control signal between two electrodes () framing each pixel, generates a flow according to a particular direction (), characterized in that, to control the switching of at least some of the pixels (P). The method includes applying to at least one neighboring pixel (), according to the direction of flow, of a pixel (P) whose switching is controlled by the electrical control signal, auxiliary electrical signals whose amplitude is less than the anchorage breaking voltage and whose rising or falling edges are temporally placed in advance or in coincidence with the active falling edge of the electrical control signal, to favor the switching of the said pixel to be controlled (P).

Liquid crystal display device and control method for a bistable nematic liquid crystal display having two stable textures comprising a uniform or slightly twisted state

The invention relates to a method for controlling a liquid crystal display, comprising a matrix of pixels arranged in crossed lines and columns and in which a switch in the state of the liquid crystal molecules, controlled by application of an electric control signal between two electrodes () enclosing each pixel, which brings about a flow in a given direction (), the pixel addressing being carried out by a line by line addressing either in a single step or in two steps, the first step comprising a collective addressing of at least a part of the screen in a given single texture, followed by a second step of line by line addressing, characterized in comprising, for controlling the switching of at least some of the pixels (P), a step for application to at least one adjacent pixel () of auxiliary electric signals wherein, depending on the direction of flow of the pixel (P) the switching of which is to be controlled, the rising or falling fronts of the auxiliary signals are temporally advanced in relation to or simultaneous with the active falling front of the electric control signal with a time offset of between 0 and several tens of microseconds at ambient temperature, such as to promote the switching of said pixel (P) for control, said auxiliary electric signals being applied in the second step when the addressing is in two steps. The invention further relates to a display.

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Leuville sur Orge, France

Jean Denis Laffitte