Patent ID: 6271819
Filing Date: 2001-08-07
Classification: G09G,H04N

Abstract:
A method for driving a matrix type electro-optical device comprising an electro-optical modulation material which has different optical response states depending on the direction of an applied electric field and which is interposed between a plurality of scan electrodes and a plurality of control electrodes to form optical elements at intersecting points of the electrodes, the method comprising the steps of:selectively supplying an initializing signal and a succeeding selection signal to one of the scan electrodes and supplying a non-selection signal to the one scan electrode when the initializing signal and selection signal are not supplied thereto;supplying data signals to the control electrodes synchronously with the supply of the selection signal to the one scan electrode for specifying the optical response state of each of the optical elements at the one scan electrode;applying an initializing pulse group comprised of a plurality of pulses to the optical elements to optically initialize the same by means of a potential difference between the initializing signal and the data signals;applying a first pulse group to the optical elements by means of a potential difference between the selection signal and the data signals to set the optical elements to desired optical response states, wherein a symmetrical negative polarity pulse necessarily exists opposite to each positive polarity pulse; andmaintaining the optical response states of the optical elements by applying a second pulse group to the optical elements by means of a potential difference between the non-selection signal and the data signals;the initializing pulse group setting the optical elements to a light-transmitting state or a light-shading state, and wherein a symmetrical negative polarity pulse necessarily exists opposite to each positive polarity pulse;the first pulse group containing a first writing pulse for setting the optical elements to a first optical response state and a second writing pulse for setting the optical elements to a second optical response state, the first writing pulse and the second writing pulse having the same pulse waveform but opposite polarities, wherein the second writing pulse is applied before applying the first writing pulse when the first optical response state is to be written and the first writing pulse is applied before applying the second writing pulse when the second optical response state is to be written; andthe second pulse group comprising pulses for maintaining optical response states of the optical elements, and wherein a symmetrical negative polarity pulse necessarily exists opposite to each positive polarity pulse.