Patent ID: 7289094
Filing Date: 2007-10-30
Classification: G09G

Abstract:
1. A drive circuit for a flat display apparatus wherein driving signals are produced by a digital to analog conversion process of image data and are used to drive signal lines of a display section wherein pixels are arranged in a matrix, comprising: an original reference voltage production circuit for producing a plurality of original reference voltages; a reference voltage production circuit formed from a plurality of voltage dividing circuits connected in series and each including a plurality of resistors connected in series and receiving the original reference voltages at the opposite ends of and at nodes between said voltage dividing circuits to output divided voltages by said voltage dividing circuits as a plurality reference voltages; a plurality of selection circuits for receiving the reference voltages as inputs thereto and selectively outputting the inputted reference voltages in accordance with the image data for the corresponding ones of said signal lines as the driving signals; and an input circuit for inputting original reference voltage setting data indicating setting of the original reference voltages; said original reference voltage production circuit including a plurality of digital to analog conversion circuits for producing a plurality of candidate voltages for the original reference voltages by means of a voltage dividing circuit for original reference voltage production and selectively outputting the candidate voltages in response to the original reference voltage setting data to produce the original reference voltages corresponding to the original reference voltage setting data; those of said digital analog conversion circuits which are for the original reference voltages other than the potentials at the opposite ends of said voltage dividing circuits being formed such that the voltage dividing circuits for original reference voltage production thereof are connected in series and the original reference voltages of the potentials at the opposite ends of said voltage dividing circuits are inputted to the opposite ends of the voltage dividing circuits for original reference voltage production; each of those of said digital to analog conversion circuit which are for the original reference voltages of the potentials at the opposite ends of said voltage dividing circuits including a power supply circuit for varying the voltage across said voltage dividing circuits for original reference voltage production in response to data for rough adjustment.