Patent ID: 6710759
Filing Date: 2004-03-23
Classification: G09G

Abstract:
A ferroelectric liquid crystal display element having pixels and comprising:a ferroelectric liquid crystal sandwiched between a pair of substrates; and means for providing a driving waveform for the element, the waveform including a reset period followed by a selection period, the reset period having a switching period and a non-switching period, wherein, during the switching period, a reset voltage exceeding a threshold voltage required to switch said ferroelectric liquid crystal is applied irrespective of display data to be written to a pixel of the element, and during said non-switching period, ionic impurities are moved by an electric field produced by a spontaneous polarization of ferroelectric liquid crystal molecules, which is reversed by the reset voltage applied during the switching period, thereby an ion electric field caused by the ionic impurities in said ferroelectric liquid crystal is aligned stably in such a direction that cancels the direction of the electric field produced by spontaneous polarization of the ferroelectric liquid crystal molecules, and said non-switching period comprising a period during which the voltage applied to the ferroelectric crystal is 0V and having a length &Dgr;T which is set so as to reduce a change in said threshold voltage to nearly zero.