Driving circuit, liquid crystal display device and method of driving the same
AssigneeLG Display Co., Ltd.
InventorsYoung Gi Hong, Jae Yeol Kim
Life of this patent
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Abstract
An LCD capable of discharging a residual voltage of a panel and a method of driving the same are provided. In the LCD, a gate signal is supplied to the liquid crystal panel during a time interval when a supply voltage is shut off, and a residual voltage is discharged.
Claims16
A driving circuit comprising:
- a gate driver;
- and
- a power supply to generate a power supply voltage, the power supply voltage is a high level when power is on and the power supply voltage is a low level when power is off,
- wherein the power supply voltage enable and disable the gate driver to be driven,
- wherein the gate driver outputs one of a gate driving signal or a discharge signal according to level of the power supply voltage,
- wherein the gate driving signal includes a scan signal having a gate high voltage and a gate low voltage,
- wherein the discharge signal is a voltage with a level equal to level of the gate high voltage, is generated when the power supply voltage is the low level and is supplied to gate lines of a liquid crystal panel to discharge a residual voltage of the liquid crystal panel,
- wherein the gate driver comprises:
- a plurality of shift registers, each connecting an output terminal thereof to a corresponding the gate line of the liquid crystal panel,
- a plurality of logic controllers, each connecting to an input terminal of a first corresponding shift register to generate a control signal having at least two states and the output terminal of a second corresponding shift register,
- wherein each of the logic controllers receive the power supply voltage and one of a gate start pulse signal or an output signal of the previous shift register,
- wherein the logic controller generates the control signal with a high level during a predetermined time when the power supply voltage is the low level,
- wherein the gate driver outputs the discharge signal when the power supply voltage is the low level and supplies the discharge signal to the gate lines.
A method of driving an liquid crystal display (LCD) having a liquid crystal panel including gate lines and data lines arranged in a matrix, a gate driver generating a gate signal to activate the gate lines, a data driver for supplying image data to the data lines, and a power supply for generating and supplying a power supply voltage to the gate driver and the data driver, the method comprising:
- displaying the image data on the liquid crystal panel in response to the gate signal when the power supply voltage is present at a high voltage;
- and
- discharging a voltage of the liquid crystal panel by a discharge signal during a predetermined time interval after the power supply voltage is shut off,
- wherein the power supply voltage is a high level when power is on and the power supply voltage is a low level when power is off,
- wherein the gate signal includes a gate high voltage and a gate low voltage,
- wherein the discharge signal is a voltage with a level equal to level of the gate high voltage, is generated when the power supply voltage is the low level and is supplied to the gate lines of the liquid crystal panel to discharge a residual voltage of the liquid crystal panel,
- wherein the predetermined time interval is between the power supply voltage changing from a high level to a low level and the gate signal changing from the gate high voltage to the gate low voltage,
- wherein the gate signal on a first gate line is sent back to the gate driver as a gate driver control signal for a second gate line.
Dependencies are inferred from the claim text.