Patent ID: 6885357

Claim:
A method for writing pixels in a cholesteric liquid crystal display having opposing rows and columns of electrodes and cholesteric liquid crystal material disposed between the rows and columns of electrodes to define an array of pixels, the cholesteric liquid crystals having a plurality of reflective states stable in the absence of an electrical field, one state having a minimum reflection, and another state with maximum reflection, comprising the steps of: a) in a pre-selection step, applying voltages to the row and column electrodes to establish a pre-selection pixel voltage having a magnitude and duration effective to change at least one possible reflective state, but ineffective to drive the liquid crystal material to a common state; b) in a selection step, applying voltages to the row and column electrodes to establish a selection pixel voltage for selecting a final reflective state for the pixel; and c) in a post-selection step, applying voltages to the row and column electrodes to establish a post selection pixel voltage for achieving a final desired reflective state.