Driving System and Multi-Gamma Driving Method for LCD Panel

• US 20080100553A1
• Filed: 12/14/2006
• Published: 05/01/2008
• Est. Priority Date: 10/26/2006
• Status: Abandoned Application

• Current Assignee: VastView Technology Inc.
• Original Assignee: VastView Technology Inc.
• Inventors: Shen, Yuh-Ren, Lin, Chang-Cheng
• Application Number:
  US11/611,109
• Publication Number:
  US 20080100553A1
• Time in Patent Office: Days
• US Class Current: 345/89
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2360/02 Graphics controller able to handle multiple formats, e.g. input or output formats
• CPC Class Codes: G09G 3/2092 Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

The present invention relates to a liquid crystal display device and a method of driving the same. The steps of the method contains: (1) upgrade the frame rate up to p/q times (p, q are natural numbers and p>q) and produce a series of output frames; (2) conduct grey level conversions for the series of output frames using different mapping curves based on different gamma values; (3) process the series of converted output frames by an appropriate gamma correction curve and presents the output frames on the LCD panel by an appropriate scanning method. In step (2) of the present invention, two grey level mapping curves, each specified by a specific gamma value, are applied alternately to the series of output frames and the two grey level mapping curves can be identical or different. Thus, the enhancement in brightness and high display performance and quality can be achieved.

Claims

1. A multi-gamma driving method for a LCD panel, comprising the steps of:

producing a series of output frames from a series of input frames by upgrading the frame rate up to p/q times (p, q are natural numbers and p>

q);

conducting grey level mapping to the pixels of the series of output frames; and

conducting gamma correction based on an appropriate gamma correction curve to the series of output frames and scanning the series of output frames to said LCD panel;

wherein said grey level mapping applies a first gamma mapping curve and a second gamma mapping curve in an appropriate alternate manner to the frame-rate-upgraded output frames.

2. The method according to claim 1, wherein at least one of the first and second gamma mapping curves is adjustable.

3. The method according to claim 1, wherein the gamma correction curve is adjustable.

4. The method according to claim 1, wherein the alternate manner is that, for two adjacent frame-rate-upgraded output frames, the grey levels of one frame'"'"'s pixels are converted by the first gamma mapping curve and the grey levels of the other frame'"'"'s pixels are converted by the second gamma mapping curve.

5. The method according to claim 1, wherein the alternate manner is that, for the frame-rate-upgraded output frames, one of the first and second gamma mapping curves is applied to convert the grey levels of at least one output frame'"'"'s pixels before the other gamma mapping curve is applied to convert the grey levels at least a subsequent output frame.

6. The method according to claim 1, wherein the alternate manner is that, for two adjacent frame-rate-upgraded output frames, the grey level of a pixel in the first frame is converted by one of the first and second gamma mapping curves;

and the grey level of the pixel in the second frame is converted by the other gamma mapping curve.

7. The method according to claim 1, wherein the alternate manner is that the rows of pixels of each frame-rate-upgraded output frame is horizontally partitioned into a first region and a second region;

for two adjacent output frames, the rows of pixels in the first frame'"'"'s first region and in the second frame'"'"'s second region are converted by one of the first and second gamma mapping curves; and

the rows of pixels in the first frame'"'"'s second region and in the second frame'"'"'s first region are converted by the other gamma mapping curve.

8. The method according to claim 4, wherein a frame-rate-upgraded output frame is completely scanned to the LCD panel before the next output frame is scanned.

9. The method according to claim 5, wherein a frame-rate-upgraded output frame is completely scanned to the LCD panel before the next output frame is scanned.

10. The method according to claim 6, wherein a frame-rate-upgraded output frame is completely scanned to the LCD panel before the next output frame is scanned.

11. The method according to claim 7, wherein a frame-rate-upgraded output frame is completely scanned to the LCD panel before the next output frame is scanned.

12. A multi-gamma driving method for a LCD panel, comprising the steps of:

producing a series of output frames from a series of input frames by upgrading the frame rate up to p/q times (p, q are natural numbers and p>

q);

determining whether dynamic images are contained in a frame-rated-upgraded output frame;

conducting grey level mapping in accordance to the decision of the previous step to the pixels of the series of output frames; and

conducting gamma correction based on an appropriate gamma correction curve to the series of output frames and scanning the series of output frames to said LCD panel;

wherein said grey level mapping applies a first gamma mapping curve and a second gamma mapping curve in an appropriate alternate manner to the frame-rate-upgraded output frames; and

, if a frame-rate-upgraded output frame contains static image, the first and second gamma mapping curves are substantially identical.

13. The method according to claim 12, wherein at least one of the first and second gamma mapping curves is adjustable.

14. The method according to claim 12, wherein the gamma correction curve is adjustable.

15. The method according to claim 12, wherein the alternate manner is that, for two adjacent frame-rate-upgraded output frames, the grey levels of one frame'"'"'s pixels are converted by the first gamma mapping curve and the grey levels of the other frame'"'"'s pixels are converted by the second gamma mapping curve.

16. The method according to claim 12, wherein the alternate manner is that, for the frame-rate-upgraded output frames, one of the first and second gamma mapping curves is applied to convert the grey levels of at least one output frame'"'"'s pixels before the other gamma mapping curve is applied to convert the grey levels at least a subsequent output frame.

17. The method according to claim 12, wherein the alternate manner is that, for two adjacent frame-rate-upgraded output frames, the grey level of a pixel in the first frame is converted by one of the first and second gamma mapping curves;

and the grey level of the pixel in the second frame is converted by the other gamma mapping curve.

18. The method according to claim 12, wherein the alternate manner is that the rows of pixels of each frame-rate-upgraded output frame is horizontally partitioned into a first region and a second region;

for two adjacent output frames, the rows of pixels in the first frame'"'"'s first region and in the second frame'"'"'s second region are converted by one of the first and second gamma mapping curves; and

the rows of pixels in the first frame'"'"'s second region and in the second frame'"'"'s first region are converted by the other gamma mapping curve.

19. The method according to claim 15, wherein a frame-rate-upgraded output frame is completely scanned to the LCD panel before the next output frame is scanned.

20. The method according to claim 16, wherein a frame-rate-upgraded output frame is completely scanned to the LCD panel before the next output frame is scanned.

21. The method according to claim 17, wherein a frame-rate-upgraded output frame is completely scanned to the LCD panel before the next output frame is scanned.

22. The method according to claim 18, wherein a frame-rate-upgraded output frame is completely scanned to the LCD panel before the next output frame is scanned.

23. A driving system to a LCD panel having a source driving circuit module and gate driving circuit module, comprising

a frame rate conversion circuit producing a series of output frames from a series of input frames by upgrading the frame rate up to p/q times (p, q are natural numbers and p>

q);

a multi-gamma driving circuit conducting grey level mapping by applying a first gamma mapping curve and a second gamma mapping curve in an appropriate alternate manner to the pixels of the series of output frames from the frame rate conversion circuit;

a timing controller scanning the series of output frames from the multi-gamma driving circuit to the LCD panel via the source driving circuit module and the gate driving circuit module; and

a gamma correction circuit conducting gamma correction based on an appropriate gamma correction curve to the frame data of the series of output frames before the frame data is applied to the source driving circuit module.

24. The driving system according to claim 23, wherein the first and second gamma mapping curves are stored in a gamma ROM.

25. The driving system according to claim 23, further comprising:

a dynamic/static image decision circuit between the frame rate conversion circuit and the multi-gamma driving circuit for determining whether dynamic images are contained in a frame-rated-upgraded output frame;

wherein, if a frame-rate-upgraded output frame contains static image, the first and second gamma mapping curves applied by the multi-gamma driving circuit are substantially identical.