Liquid Crystal Display

• US 20070164957A1
• Filed: 12/28/2006
• Published: 07/19/2007
• Est. Priority Date: 01/13/2006
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: Chi Mei Optoelectronics (InnoLux Corporation)
• Inventors: Hsu, Che-Ming, Hsieh, Chih-Yung, Chen, Chien-Hong, Hsieh, Ming-Feng, HO, I-Lin
• Granted Patent: US 8,362,995 B2
• Time in Patent Office: Days
• US Class Current: 345/90
• 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 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 2320/0219 Reducing feedthrough effects in active matrix panels, i.e. voltage changes on the scan electrode influencing the pixel voltage due to capacitive coupling
• CPC Class Codes: G09G 2320/028 by changing the viewing angle properties, e.g. widening the viewing angle, adapting the viewing angle to the view direction
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3655 Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors
• CPC Class Codes: G09G 3/3677 suitable for active matrices only

Abstract

A multi-domain LCD panel includes data lines, scan lines and pixels. Each pixel includes first and second sub-pixels respectively having first and second storage capacitors. A first data switch is selectively coupled to a first terminal of the first capacitor and one of the data lines. A second data switch is selectively coupled to a first terminal of the second capacitor and one of the data lines. First and second bias lines are respectively coupled to second terminals of the first and second capacitors. When a corresponding scan line is enabled, the first and second data switches turn on such that a signal on the data line is transmitted to the first and second sub-pixels. After the scan line is disabled, levels of the first and second bias lines are changed such that pixel voltages of the first and second sub-pixels differ from each other.

Claims

1. An LCD (Liquid Crystal Display) panel, comprising:

a data line extending in a first direction;

a scan line extending in a second direction substantially perpendicular to the first direction;

a pixel formed at an intersection between the data line and the scan line, the pixel comprising;

a first sub-pixel, which comprises a first switch, a first liquid crystal capacitor and a first storage capacitor, wherein the first switch has a first terminal coupled to the scan line, a second terminal coupled to the data line, and a third terminal coupled to a first terminal of the first liquid crystal capacitor and a first terminal of the first storage capacitor; and

a second sub-pixel, which comprises a second switch, a second liquid crystal capacitor and a second storage capacitor, wherein the second switch has a first terminal coupled to the scan line, a second terminal coupled to the data line, and a third terminal coupled to a first terminal of the second liquid crystal capacitor and a first terminal of the second storage capacitor;

a first bias line electrically connected to a second terminal of the first storage capacitor; and

a second bias line electrically connected to a second terminal of the second storage capacitor, wherein;

when the scan line is enabled, a first data switch and a second data switch turn on to enable a signal on the data line to be transmitted to the first sub-pixel and the second sub-pixel; and

after the scan line is disabled, levels of the first bias line and the second bias line respectively change to make pixel voltages of the first sub-pixel and the second sub-pixel different from each other.

2. The panel according to claim 1, wherein the first bias line has a first level before the scan line is enabled, the first level when the scan line is enabled, and a second level after the scan line is disabled.

3. The panel according to claim 1, wherein the second bias line has a third level before the scan line is enabled, the third level when the scan line is enabled, and a fourth level after the scan line is disabled.

4. The panel according to claim 1, wherein the first bias line has a first level before the scan line is enabled, a second level when the scan line is enabled, and the first level after the scan line is disabled.

5. The panel according to claim 1, wherein the second bias line has a third level before the scan line is enabled, a fourth level when the scan line is enabled, and the third level after the scan line is disabled.

6. The panel according to claim 1, wherein the LCD panel comprises a gate driver, which comprises a plurality of output pins for respectively driving the scan line, the first bias line and the second bias line.

7. The panel according to claim 1, wherein the LCD panel comprises a first gate driver for driving the scan line, and a second gate driver for driving the first bias line and the second bias line.

8. The panel according to claim 7, wherein the first gate driver and the second gate driver are disposed on one side of the LCD panel.

9. The panel according to claim 7, wherein the first gate driver and the second gate driver are disposed on opposite sides of the LCD panel.

10. The panel according to claim 1, wherein the LCD panel comprises a first gate driver and a second gate driver, which are disposed on opposite sides of the LCD panel and commonly drive the scan line, and a third gate driver and a fourth gate driver, which are disposed on the opposite sides of the LCD panel and commonly drive the first bias line and the second bias line.

11. The panel according to claim 1, comprising a plurality of the scan lines defined as first scan lines and second scan lines, and a plurality of the pixels defined as first pixels and second pixels, wherein the first pixels and the second pixels are respectively arranged in directions perpendicular to each other, and the second bias line is shared by the second sub-pixel of the first pixel and the first sub-pixel of the second pixel.

12. The panel according to claim 11, further comprising a bias generating circuit, which is formed on a substrate of the LCD panel, for driving the first bias line and the second bias line according to the first scan line and the second scan line.

13. The panel according to claim 12, wherein the bias generating circuit comprises at least one bias unit, which is electrically connected to the first scan line and the second scan line and is electrically connected to the first bias line and the second bias line.

14. The panel according to claim 1, wherein a phase difference between the levels of the first bias line and the second bias line ranges from 180 to 360 degrees.

15. An LCD (Liquid Crystal Display) panel, comprising:

a data line extending in a first direction;

a scan line extending in a second direction substantially perpendicular to the first direction;

a pixel formed at an intersection between the data line and the scan line, the pixel comprising;

a first sub-pixel, which comprises a first switch, a first liquid crystal capacitor and a first storage capacitor, wherein the first switch has a first terminal coupled to the scan line, a second terminal coupled to the data line, and a third terminal coupled to a first terminal of the first liquid crystal capacitor and a first terminal of the first storage capacitor; and

a second sub-pixel, which comprises a second switch, a second liquid crystal capacitor and a second storage capacitor, wherein the second switch has a first terminal coupled to the scan line, a second terminal coupled to the data line, and a third terminal coupled to a first terminal of the second liquid crystal capacitor and a first terminal of the second storage capacitor;

a first bias line electrically connected to a second terminal of the first storage capacitor; and

a second bias line electrically connected to a second terminal of the second storage capacitor, wherein;

when the scan line is enabled, a first data switch and a second data switch turn on to enable a signal on the data line to be transmitted to the first sub-pixel and the second sub-pixel;

after the scan line is disabled, levels of the first bias line and the second bias line respectively change to make pixel voltages of the first sub-pixel and the second sub-pixel be slightly different from each other; and

the first bias line and the second bias line further respectively change the levels thereof at least one time in a frame time period.

16. An LCD (Liquid Crystal Display), comprising:

a source driver;

a gate driver for outputting a scan signal;

a bias generating circuit for outputting a first bias signal and a second bias signal according to the scan signal; and

a LCD panel, which comprises;

a data line, which extends in a first direction and is electrically connected to the source driver;

a scan line, which extends in a second direction substantially perpendicular to the first direction, for receiving the scan signal;

a pixel formed at an intersection of the data line and the scan line, the pixel comprising;

a first sub-pixel, which comprises a first switch, a first liquid crystal capacitor and a first storage capacitor, wherein the first switch has a first terminal coupled to the scan line, a second terminal coupled to the data line, and a third terminal coupled to a first terminal of the first liquid crystal capacitor and a first terminal of the first storage capacitor; and

a second sub-pixel, which comprises a second switch, a second liquid crystal capacitor and a second storage capacitor, wherein the second switch has a first terminal coupled to the scan line, a second terminal coupled to the data line, and a third terminal coupled to a first terminal of the second liquid crystal capacitor and a first terminal of the second storage capacitor;

a first bias line, which receives the first bias signal and is electrically connected to a second terminal of the first storage capacitor; and

a second bias line, which receives the second bias signal and is electrically connected to a second terminal of the second storage capacitor, wherein;

when the scan line is enabled, a first data switch and a second data switch turn on to enable a signal on the data line to be transmitted to the first sub-pixel and the second sub-pixel; and

after the scan line is disabled, levels of the first bias signal and the second bias signal respectively change to make pixel voltages of the first sub-pixel and the second sub-pixel be slightly different from each other.