Patent ID: 7245282
Filing Date: 2007-07-17
Classification: G09G

Abstract:
1. A method for addressing a bistable nematic liquid crystal device having a layer of nematic liquid crystal material disposed between two cell walls and row and column electrodes disposed on the cell walls to form an addressable matrix of pixels, the liquid crystal material being latchable between two stable molecular configurations upon application of appropriate voltage pulses and having at least one row driver for applying voltages to said row electrodes and at least one column driver for applying voltages to said columns, the method comprising the steps of; each said row driver supplying an active row voltage waveform to each row electrode sequentially for a line address time whilst simultaneously supplying a non-active row voltage waveform to every other row electrode for the line address time each said column driver supplying one of two data voltage waveforms to each column electrode simultaneously during the line address time, wherein said row and data voltage waveforms are such that the resultant voltage waveform at each pixel on the active row has a blanking portion that causes the liquid material to be latched to one stable state and a discriminating portion that causes the liquid crystal material to be selectively latched or not to the other stable state depending on the data voltage waveform applied to that column and wherein said blanking portion immediately precedes said discriminating portion, and such that the liquid crystal material at each pixel on a non-active row is not latched from its current stable state, and wherein the resultant voltage waveform at each pixel is dc balanced over the line address time.