Nemoptic

Romain Vercelletto

Jacques Angele

Philippe Martinot-Lagarde

Thierry Elbhar

Ivan N Dozov

Daniel Stoenescu

Ivan Dozov

The present invention provides a display device comprising a bistable nematic liquid crystal matrix screen with breaking of anchoring, the device being characterized in that it includes addressing means suitable for generating and applying control signals to each pixel of the matrix screen, the control signals having sloping rising edges presenting a gradient lying in the range 0.5 V/&#x3bc;s to 0.0001 V/&#x3bc;s.

Bistable nematic liquid crystal display method and device

A method of electrically addressing a matrix screen of bistable nematic liquid crystals with breaking of anchoring is disclosed. Controlled electrical signals are applied respectively to row electrodes and to column electrodes of the screen. A plurality of rows are simultaneously addressed using similar row signals that are offset in time by a duration greater than or equal to the time column voltages that are applied. The row addressing signals have, in a first period, at least one voltage value serving to break the anchoring of all of the pixels in the row. This is followed by a second period that enables the final states of the pixels making up the address row to be determined. The final states are a function of the value of each of the electrical signals applied to the corresponding columns.

Bistable liquid crystal display device including improved addressing means

The present invention relates to a nematic bistable display device, characterized in that it comprises control means () for producing, after the anchoring is broken, hybrid textures in which two bistable textures coexist in a controlled proportion within the same pixel, these being separated by 180&#xb0; volume disclination lines or by 180&#xb0; reorientation walls on one of the surfaces, and means () for the long-term stabilization of the hybrid textures by transformation of the volume lines into surface walls and the immobilization of these walls on the surface.

Nematic liquid crystal bistable display device with grey level

This invention concerns a process for addressing a bistable liquid crystal material screen, characterized in that it comprises at least the step consisting of applying, to the screen column electrodes, an electrical signal whose characteristics are adapted to reduce the mean quadratic voltage of the parasite pixel pulses, in order to reduce the parasitic addressing optical effects.

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Poissy, France

Romain Vercelletto