LCD and driving method thereof

• US 7,215,311 B2
• Filed: 01/17/2002
• Issued: 05/08/2007
• Est. Priority Date: 02/26/2001
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Young-Ki
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): Nguyen; Jennifer T.
• Application Number:
  US10/046,772
• Publication Number:
  US 20020118154A1
• Time in Patent Office: 1,937 Days
• Field of Search: 345 87-100, 345210-214, 345204-206, 349/33, 349/34, 349/37
• US Class Current: 345/98
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2310/0248 Precharge or discharge of column electrodes before or after applying exact column voltages
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2330/023 using energy recovery or conservation
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections

Abstract

There are provided an LCD and a driving method thereof for charging each data line of the LCD with sufficient data voltage. The present invention has a switching device installed between every adjacent data line, and the switching device connects the data line before a gate-on voltage is applied to the gate line thereby pre-charging the data line by charge sharing effect between the connected adjacent data lines and significantly reducing the change of the data line voltage by parasitic capacitance.

Claims

1. A method for driving a liquid crystal display comprising a plurality of gate lines, a plurality of insulated data lines crossing the gate lines, and a plurality of thin film transistors, each having a gate electrode connected to a gate line and a source electrode connected to a data line, comprising the steps of:

sequentially supplying a gate-on voltage for turning on the thin film transistor to the gate lines;

connecting the adjacent data lines and charging the data lines with a predetermined voltage; and

applying the data voltage to the data lines, wherein the adjacent data lines are connected after the voltage applied to a previous gate line is changed to a gate-off voltage, and the adjacent data lines are disconnected in a predetermined time after the gate-on voltage is applied to the gate line.

2. The method of claim 1, wherein polarities of the data voltages applied to the adjacent data lines are opposite to each other.

3. The method of claim 1, wherein the predetermined voltage is close to a common voltage.

4. A liquid crystal display, comprising:

a liquid crystal panel including a plurality of gate lines, a plurality of first and second data lines, and a plurality of first and second thin film transistors each having a gate electrode connected to a gate line, a source electrode connected to a data line, and a drain electrode connected to a liquid crystal capacitor;

a gate driver for sequentially supplying a gate-on voltage to the gate lines for turning on the first and second thin film transistors;

a first data driver for applying first data voltages to the first data lines;

a second data driver for applying second data voltages to the second data lines;

a first data line sharing switch having a plurality of first commonly controlled switching devices, each of which is formed between each of the adjacent first data lines, respectively;

a second data line sharing switch having a plurality of second commonly controlled switching devices, each of which is formed between each of the adjacent second data lines, respectively; and

a sharing signal generator for outputting a first sharing control signal for turning on the first switching devices to connect the adjacent first data lines and a second sharing control signal for turning on the second switching devices to connect the adjacent second data lines,

wherein the first thin film transistors are disposed between the first data line sharing switch and the first data driver, and the second thin film transistors are disposed between the second data line sharing switch and the second data driver.

5. The liquid crystal display of claim 4, wherein the first and second data line sharing switches are formed on the liquid crystal panel.

6. The liquid crystal display of claim 5, wherein the first and second switching devices comprise third thin film transistors, the first switching devices having commonly connected gate terminals, and the second switching devices having commonly connected gate terminals, respectively.

7. The liquid crystal display of claim 6, wherein the third thin film transistors are incorporated in the liquid crystal panel.

8. The liquid crystal display of claim 7, wherein the first to third thin film transistors comprise amorphous transistors or polycrystal transistors.

9. The liquid crystal display of claim 4, wherein the first and second data line sharing switches are placed between the first and second data drivers.

10. A liquid crystal display as defined in claim 4 wherein the first data driver is disposed for applying first dot reverse data voltages to the first data lines, and the second data driver is disposed for applying second dot reverse data voltages to the second data lines.

11. A liquid crystal display as defined in claim 4 wherein the first commonly controlled switching devices are connected in series, and the second commonly controlled switching devices are connected in series.

12. A liquid crystal display as defined in claim 4 wherein the data lines have minimized line capacitance.

13. A liquid crystal display, comprising:

a liquid crystal panel including a plurality of gate lines, a plurality of insulated data lines crossing the gate lines, and a plurality of first thin film transistors each having a gate electrode connected to a gate line, a source electrode connected to a data line, and a drain electrode connected to a liquid crystal capacitor;

a gate driver for sequentially supplying a gate-on voltage to the gate lines for turning on the thin film transistors;

a data driver for applying a data voltage to the data lines;

a data line sharing switch having a plurality of switching devices, each of which formed between the adjacent data lines; and

a sharing signal generator for outputting a sharing control signal for turning on the switching devices to connect the adjacent data lines, wherein the first thin film transistors are disposed between the data line sharing switch and the data driver,

wherein the adjacent data lines are connected after the voltage applied to a previous gate line is changed to a gate-off voltage, and the adjacent data lines are disconnected in a predetermined time after the gate-on voltage is applied to the gate line.

14. A liquid crystal display, comprising:

a liquid crystal panel including a plurality of gate lines, a plurality of first and second data lines, and a plurality of thin film transistors consisting of first and second thin film transistors each having a gate electrode connected to a gate line, a source electrode connected to a data line, and a drain electrode connected to a liquid crystal capacitor;

a gate driver for sequentially supplying a gate-on voltage to the gate lines for turning on the first and second thin film transistors;

a first data driver for applying first data voltages to the first data lines;

a second data driver for applying second data voltages to the second data lines;

a first data line sharing switch having a plurality of first commonly controlled switching devices, each of which is formed between each of the adjacent first data lines, respectively;

a second data line sharing switch having a plurality of second commonly controlled switching devices, each of which is formed between each of the adjacent second data lines, respectively; and

a sharing signal generator for outputting a first sharing control signal across a first sharing control signal line for turning on the first switching devices to connect the adjacent first data lines and outputting a second sharing control signal across a second sharing control signal line for turning on the second switching devices to connect the adjacent second data lines,

wherein the first thin film transistors are disposed between the first data line sharing switch and the first data driver, and the second thin film transistors are disposed between the second data line sharing switch and the second data driver.

15. A liquid crystal display as defined in claim 14 wherein the first data driver is disposed for applying first dot reverse data voltages to the first data lines and the second data driver is disposed for applying second dot reverse data voltages to the second data lines.

16. A liquid crystal display as defined in claim 14 wherein the first commonly controlled switching devices are connected in series, and the second commonly controlled switching devices are connected in series.

17. A liquid crystal display as defined in claim 14 wherein the data lines have minimized line capacitance.