Patent ID: 7573470
Filing Date: 2009-08-11
Classification: G09G

Abstract:
1. A method for driving a liquid crystal display device having a data driving integrated circuit, the method comprising: providing a liquid crystal device that includes a external pre-charge voltage source, located on a printed circuit board, separated from the driving integrated circuit, wherein the data driving integrated circuit includes an output buffer, an output terminal connected with a data line, and a pre-charging part connected between the output buffer and the output terminal, wherein the output buffer includes first and second internal resistors, connected between VDD and GND, and a third internal resistor connected between a node, between the first and second internal resistors, and the output terminal, during a first period, turning off a first switch connected between the third internal resistor of the output buffer and the output terminal, while turning on a second switch for pre-charging the output terminal with a positive pre-charge voltage and turning off a third switch, wherein the second switch is connected between a first supply line, supplying the positive pre-charge voltage from the external pre-charge voltage source, and the output terminal, and the third switch is connected between a second supply line, supplying a negative pre-charge from the external pre-charge voltage source, and the output terminal; during a second period after the first period, turning on the first switch for charging the output terminal with a positive data voltage from the output buffer, using a charging current through the first and third internal resistors or a discharging current through the second and third internal resistors, while turning off the second and third switches; during a third period after the second period, turning off the first switch while turning on the third switch to pre-charge for pre-charging the output terminal with the negative pre-charge voltage and turning off the second switch, and during a fourth period after the third period, turning on the first switch for charging the output terminal with a negative data voltage from the output buffer, using the charging current through the first and third internal resistors or the discharging current through the second and third internal resistors, while turning off the second and third switches, wherein the positive pre-charge voltage is ¾ VDD and the negative pre-charge voltage is be ¼ VDD.