Method and system of compensating kickback voltage for a liquid crystal display device
AssigneeLG. Philips LCD Co., Ltd.
InventorJin-Cheol Hong
Life of this patent
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Abstract
A method of compensating for a kickback voltage for a common electrode of the LCD device having a gate line where the gate signal is applied from a first end to a second thereof includes applying a constant current to the common electrode at a location corresponding to the first end of the gate line, and applying a common voltage to the common electrode at a location corresponding to the second end of the gate line. The constant current applied to the common electrode helps to maintain the difference of the common voltages between the positions corresponding to first and second ends of the gate line.
Claims25
An active matrix type liquid crystal display (LCD) system, comprising:
- a first substrate including a plurality of pixel electrodes arranged in matrix form, a plurality of thin film transistors each having a gate electrode and a source electrode, a plurality of data lines transmitting data signals to the source electrodes, and a plurality of gate lines transmitting gate signals to the gate electrodes from a first end to a second end of each gate line;
- a second substrate opposing to the first substrate, the second substrate having a common electrode facing the plurality of pixel electrodes of the first substrate;
- a liquid crystal layer between the first and second substrates;
- a gate line driving circuit transmitting the gate signals to the first ends of the plurality of gate lines;
- a data line driving circuit transmitting the data signals to the plurality of data lines;
- a constant current source for supplying a constant current to a first position of the common electrode corresponding to the first end of one gate line, the first position having a first contact resistance;
- a common voltage supply for applying a common voltage to a second position of the common electrode corresponding to the second end of the one gate line, the second position having a second contact resistance;
- first and second connection points between the first and second substrates, respectively, through the first and second connection points the constant current and the common voltage being transmitted to the second substrate from the first substrate;
- and
- wherein the first contact resistance is between the first position of the common electrode and the first connection point, and wherein the second contact resistance is between the second position of the common electrode and the second connection point.
A method of adjusting a common voltage for an active matrix liquid crystal display device, the liquid crystal display device including a first substrate including a plurality of pixel electrodes arranged in matrix form, a plurality of thin film transistors having a gate electrode and a source electrode, a plurality of data lines transmitting data signals to the source electrode, and a plurality of gate lines transmitting gate signals to the gate electrode from a first end to a second end thereof;
- a second substrate opposing to the first substrate, the second substrate having a common electrode facing the plurality of pixel electrodes of the first substrate;
- a liquid crystal layer between the first and second substrates;
- a gate line driving circuit transmitting gate signals to the first ends of the plurality of gate lines;
- and a data line driving circuit transmitting data signals to the plurality of data lines, the method, comprising:
- applying a constant current to the common electrode through a second connection point having a second contact resistance at a position corresponding to the first end of the plurality of gate lines;
- and
- applying a common voltage to the common electrode through a first connection point having a first contact resistance at a position corresponding to the second end of the plurality of gate lines.
A liquid crystal display (LCD) device, comprising:
- a first substrate including a plurality of thin film transistors each having,
- a gate electrode, a source electrode, and a drain electrode, and
- a plurality of pixel each connected a corresponding one of the drain electrodes,
- a plurality of data lines transmitting data signals to the source electrodes, and
- a plurality of gate lines transmitting gate signals to the gate electrodes;
- a second substrate opposing to the first substrate, the second substrate having a common electrode facing the plurality of pixel electrodes of the first substrate;
- and
- a liquid crystal layer between the first and second substrates;
- wherein a constant current is applied to a first position of the common electrode, and
- wherein a common voltage is applied to a second position of the common electrode.
A liquid crystal display (LCD) panel, comprising:
- a first substrate including a plurality of thin film transistors each having,
- a gate electrode, a source electrode, and a drain electrode, and
- a plurality of pixel each connected a corresponding one of the drain electrodes,
- a plurality of data lines transmitting data signals to the source electrodes, and
- a plurality of gate lines transmitting gate signals to the gate electrodes;
- a second substrate opposing to the first substrate, the second substrate having a common electrode facing the plurality of pixel electrodes of the first substrate;
- a liquid crystal layer between the first and second substrates;
- a constant current source for applying a constant current to a first position of the common electrode, and
- a common voltage supply for applying a common voltage to a second position of the common electrode.
Dependencies are inferred from the claim text.