Electronic addressing of ferroelectric and flexoelectric liquid crystal devices

An addressing method for driving an array of electro-optic elements with a linear electric response, comprising a helix-free polymer or non-polymer liquid crystal with a ferro-electric or flexoelectric response and with at least two states, termed UP and DOWN polarization, interposed between a pair of substrates covered, on their opposing sides by, respectively, one set of N.gtoreq.1 lines, comprising horizontal stripe electrode rows and one set of M.gtoreq.1 lines, comprising vertical stripe electrode columns, and with each row-column crossing defining an electro-optic picture element or pixel, said method comprising a first step where, during a line addressing Time .tau..sub.e, one type of voltage pulse train with a shape distributed over n time slots .tau., .tau..sub.e =n.tau., is fed to a selected row whereas simultaneously one of two kinds of different pulse trains of the same duration is fed to each column, said pulse trains being so shaped that in the corresponding superimposed pulse train resulting from their superposition on each of the pixels in the selected row, there will appear a polar switching pulse of positive or negative sign, according to whether the pixel should be written in the UP or DOWN state, respectively, said polar pulse being characterized by an area in pulse amplitude and duration A.sub.s =(V.tau.).sub.s larger than a critical threshold value A.sub.c, whereas the pulse trains applied to pixels of the non-selected rows only contain voltage pulses having a subcritical area, A.sub.ns <A.sub.c, said method further comprising repeating said step whereby rows are addressed in succession, thus writing the complete information embodied in all UP and DOWN states in one and the same scan of duration N .tau..sub.e.