Patent ID: 7199779
Filing Date: 2007-04-03
Classification: G02F,G09G

Abstract:
1. A display driver which drives a plurality of data lines of an electro-optical device, the electro-optical device having a plurality of scanning lines, the data lines which are alternately arranged inwardly from opposite sides of the electro-optical device in the shape of comb teeth, a plurality of switching elements respectively connected to the scanning lines and the data lines, and a plurality of pixel electrodes respectively connected to the switching elements, the display driver comprising: a grayscale bus to which grayscale data is supplied corresponding to an arrangement order of the data lines; a first bidirectional shift register which shifts a shift start signal in a first shift direction and shifts a first opposite directional shift start signal in a second shift direction which is opposite to the first shift direction, based on a first shift clock signal, and outputs a shift output shifted in one of the first and second shift directions specified by a first shift direction control signal; a second bidirectional shift register which shifts the shift start signal in the second shift direction and shifts a second opposite directional shift start signal in the first shift direction, based on a second shift clock signal, and outputs a shift output shifted in one of the first and second shift directions specified by a second shift direction control signal; a drive mode setting register in which one of a normal drive mode and a comb-tooth drive mode is set; a first shift start signal switch circuit which outputs the shift start signal or a shift output in a final stage of the second bidirectional shift register as the first opposite directional shift start signal, corresponding to the content of the drive mode setting register, the shift output having been shifted in the second shift direction in the second bidirectional shift register; a second shift start signal switch circuit which outputs the shift start signal or a shift output in a final stage of the first bidirectional shift register as the second opposite directional shift start signal, corresponding to the content of the drive mode setting register, the shift output having been shifted in the first shift direction in the first bidirectional shift register; a first data latch which has a plurality of flip-flops each of which holds the grayscale data corresponding to one of the data lines based on a shift output in each stage of the first bidirectional shift register; a second data latch which has a plurality of flip-flops each of which holds the grayscale data corresponding to one of the data lines based on a shift output in each stage of the second bidirectional shift register; and a data line driver circuit in which a plurality of data output sections are arranged corresponding to the arrangement order of the data lines, each of the data output sections driving one of the data lines based on the grayscale data held in one of the flip-flops of the first or second data latch.