Patent ID: 6667732
Filing Date: 2003-12-23
Classification: G09G

Abstract:
A method of driving a liquid crystal device comprising a first substrate on which a plurality of electrodes are formed, a second substrate on which a plurality of segment electrodes are formed, and a liquid crystal interposed between the first substrate and the second substrate, and applying a voltage which changes into at least an ON voltage, an OFF voltage and an intermediate voltage therebetween in accordance with a pulse amplitude modulation to a pixel formed at each intersection point of the common electrodes and the segment electrodes, the method comprising:a first driving step of driving the liquid crystal device under a condition of a first duty and a first bias ratio; and a second driving step of driving the liquid crystal device under a condition of a second duty and a second bias ratio, wherein the first and the second duties and the first and the second bias ratios are set so that a root-mean-square voltage applied to the pixel when the intermediate voltage is applied to the pixel in the first driving step equals a root-mean-square voltage applied to the pixel when the intermediate voltage is applied to the pixel in the second driving step, thereby the half-tone display both in the first and second driving step become constant.