LIQUID CRYSTAL DISPLAY

• US 20110267554A1
• Filed: 07/12/2011
• Published: 11/03/2011
• Est. Priority Date: 11/26/2007
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Lee, Seung-Hoon, Yang, Young-Chol, Lu, JianGang
• Granted Patent: US 9,134,581 B2
• Time in Patent Office: Days
• US Class Current: 349/41
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence
• CPC Class Codes: G09G 2300/0443 with several sub-pixels for the same colour in a pixel, not specifically used to display gradations G09G3/364 takes precedence
• CPC Class Codes: G09G 2300/0447 for multi-domain technique to improve the viewing angle in a liquid crystal display, such as multi-vertical alignment [MVA]
• CPC Class Codes: G09G 2300/0814 used for selection purposes, e.g. logical AND for partial update
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2320/068 for control of viewing angle adjustment
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes

Abstract

A liquid crystal display includes first and second gate lines arranged in parallel to each other and sequentially transmitting a gate voltage, a data line crossing the first and second gate lines and transmitting a data voltage, a pixel electrode constituted by first and second sub-pixel electrodes and electrically disconnected from each other, a first switching element connected to the first gate line, the data line, and the first sub-pixel electrode, a second switching element connected to the first gate line, the data line, and the second sub-pixel electrode, a third switching element connected to the first sub-pixel electrode across a charge-sharing capacitor, and a fourth switching element connected to the second gate line and the second sub-pixel electrode and connected to the first sub-pixel electrode across the charge-sharing capacitor.

Claims

1. A liquid crystal display comprising:

first and second gate lines arranged in parallel to each other and sequentially transmitting a gate voltage;

a data line crossing the first and second gate lines and transmitting a data voltage;

a pixel electrode constituted by first and second sub-pixel electrodes electrically disconnected from each other;

a first switching element connected to the first gate line, the data line, and the first sub-pixel electrode;

a second switching element connected to the first gate line, the data line, and the second sub-pixel electrode;

a third switching element connected to the first sub-pixel electrode across a charge-sharing capacitor; and

a fourth switching element connected to the second gate line and the second sub-pixel electrode and connected to the first sub-pixel electrode across the charge-sharing capacitor.

2. The liquid crystal display of claim 1, further comprising a storage line parallel to the gate lines and transmitting a common voltage, wherein the third switching element has a control terminal connected to the first gate line, an output terminal connected to the charge-sharing capacitor, and an input terminal connected to the storage line.

3. The liquid crystal display of claim 2, wherein the input terminal of the third switching element is directly connected to the storage line.

4. The liquid crystal display of claim 3, wherein when a gate-on voltage is applied to the first gate line, a voltage corresponding to a difference between the data voltage and the common voltage is charged in the charge-sharing capacitor.

5. The liquid crystal display of claim 2, wherein the input terminal of the third switching element is connected to the storage line via an auxiliary capacitor.

6. The liquid crystal display of claim 1, further comprising a charge-sharing wire parallel to the data line and transmitting a charge-sharing voltage, wherein the third switching element has a control terminal connected to the first gate line, an output terminal connected to the charge-sharing capacitor, and an input terminal connected to the charge-sharing wire.

7. The liquid crystal display of claim 6, wherein the polarity of the charge-sharing voltage is opposite to the polarity of the data voltage.

8. The liquid crystal display of claim 6, wherein after charge sharing is performed between the pixel voltages of the first and second sub-pixel electrodes, the pixel voltages of the first and second sub-pixel electrodes are boosted relative to the data voltage.

9. The liquid crystal display of claim 8, further comprising:

a first liquid crystal (LC) capacitor and a first storage capacitor which are cascade-connected to the first switching element; and

a second LC capacitor and a second storage capacitor cascade-connected to the second switching element, wherein the data voltage and the charge-sharing voltage satisfy the following relationship;

10. The liquid crystal display of claim 1, further comprising lower and upper panels facing each other, and a liquid crystal layer interposed between the panels.

11. A liquid crystal display comprising:

a gate driver driving first and second gate lines arranged in parallel to each other and sequentially transmitting a gate voltage;

a data driver driving a data line crossing the first and second gate lines and transmitting a data voltage;

a signal controller controlling the gate driver and the data driver;

a pixel electrode constituted by first and second sub-pixel electrodes electrically disconnected from each other;

a first switching element connected to the first gate line, the data line, and the first sub-pixel electrode;

a second switching element connected to the first gate line, the data line, and the second sub-pixel electrode;

a third switching element connected to the first sub-pixel electrode across a charge-sharing capacitor; and

a fourth switching element connected to the second gate line and the second sub-pixel electrode and connected to the first sub-pixel electrode across the charge-sharing capacitor.

12. The liquid crystal display of claim 11, further comprising a storage line parallel to the gate lines and transmitting a common voltage, wherein the third switching element has a control terminal connected to the first gate line, an output terminal connected to the charge-sharing capacitor, and an input terminal connected to the storage line.

13. The liquid crystal display of claim 12, wherein the input terminal of the third switching element is directly connected to the storage line.

14. The liquid crystal display of claim 13, wherein when a gate-on voltage is applied to the first gate line, a voltage corresponding to a difference between the data voltage and the common voltage is charged in the charge-sharing capacitor.

15. The liquid crystal display of claim 12, wherein the input terminal of the third switching element is connected to the storage line via an auxiliary capacitor.

16. The liquid crystal display of claim 11, further comprising a charge-sharing wire parallel to the data line and transmitting a charge-sharing voltage, wherein the third switching element has a control terminal connected to the first gate line, an output terminal connected to the charge-sharing capacitor, and an input terminal connected to the charge-sharing wire.

17. The liquid crystal display of claim 16, wherein the polarity of the charge-sharing voltage is opposite to the polarity of the data voltage.

18. The liquid crystal display of claim 16, wherein after charge sharing is performed between the pixel voltages of the first and second sub-pixel electrodes, the pixel voltages of the first and second sub-pixel electrodes are boosted relative to the data voltage.

19. The liquid crystal display of claim 18, further comprising:

a first liquid crystal (LC) capacitor and a first storage capacitor which are cascade-connected to the first switching element; and

a second LC capacitor and a second storage capacitor cascade-connected to the second switching element, wherein the data voltage and the charge-sharing voltage satisfy the following relationship;

20. The liquid crystal display of claim 11, further comprising lower and upper panels facing each other and a liquid crystal layer interposed between the panels.