Patent ID: 6084561
Filing Date: 2000-07-04
Classification: G09G

Abstract:
A liquid crystal controller for controlling a liquid crystal display device of passive matrix type in which pixels are formed at intersecting points of scanning electrodes and data electrodes disposed orthogonally to each other and the pixels have a transmission factor which is varied in accordance with an average of squared differences of voltages applied to the scanning electrodes and the data electrodes;said liquid crystal controller including a frame memory which converts a frame frequency in order to drive said liquid crystal display device of passive matrix type with a higher frame frequency than an inputted frame frequency;said liquid crystal controller performing gray scale processing using a frame rate control or FRC processing in which several frames are set to one period and a rate of display on and off is set in said period in order to convert input gray scale data of n bits into one bit;said liquid crystal controller comprising gray scale processors including a first frequency gray scale processor disposed before said frame memory and which converts several bits of said input n-bit gray scale data to one bit in accordance with first FRC patterns and a second frequency gray scale processor disposed after said frame memory which converts remaining several bits of said input n-bit gray scale data to one bit in accordance with second FRC patterns;wherein said liquid crystal controller obtains display signals by both of said first and second gray scale processors being combined to be converted into said output display data of one bit.