Patent ID: 7724221

Claim:
A display device comprising a bistable nematic liquid crystal matrix screen ( 58 ) with breaking of anchoring, including addressing means ( 56 ) suitable for generating and applying control signals to each pixel of the matrix screen, the device being characterized in that the control signals have sloping rising edges (Fm) presenting a gradient lying in the range 0.1 V/μs to 0.005 V/μs and that the rising edge (Fm) presents a duration τ R greater than 300 μs, wherein the addressing means ( 56 ) are adapted to generate signals comprising two stages: a first stage for breaking anchoring, and a second stage for selection purposes, and in order to obtain a uniform texture, the addressing means ( 56 ) are adapted to generate signals for which the drop between two successive levels in the descending edge of the selection stage does not exceed a critical threshold value ΔV, while for obtaining a twisted texture, the descending edge includes at least one sudden drop greater than the critical threshold value ΔV.