Patent ID: 6275209
Filing Date: 2001-08-14
Classification: G09G

Abstract:
A liquid crystal display driver comprising:reference voltage producing means for producing a variable reference voltage from two predetermined voltages;driving voltage producing means for producing from a predetermined voltage and said reference voltage a plurality of driving voltages to be supplied to a liquid crystal display;data-storage means for storing data that represents a voltage to which said reference voltage is to be set;control means for controlling said reference voltage producing means to set said reference voltage to the voltage represented by said data; andwherein said reference voltage producing means comprises:a first resistor of which a first end is connected to the lower one of said two predetermined voltages;a plurality of resistors that are connected in series between the higher one of said two predetermined voltages and a second end of said first resistor;a plurality of switching devices that are connected individually in parallel with said plurality of resistors,said reference voltage appearing at the second end of said first resistor, andwherein said control means sets said reference voltage to the voltage represented by said data by controlling said plurality of switching devices individually between conducting and non-conducting states in accordance with said data.