Liquid crystal display device and driving method thereof

• US 20070152951A1
• Filed: 10/31/2006
• Published: 07/05/2007
• Est. Priority Date: 12/29/2005
• Status: Abandoned Application

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Ahn, Ji Young
• Application Number:
  US11/589,876
• Publication Number:
  US 20070152951A1
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
• CPC Class Codes: G09G 3/3666 with the matrix divided into sections

Abstract

A liquid crystal display device includes a liquid crystal panel having first data lines crossing gate lines on a first region of the liquid crystal panel and second data lines crossing the gate lines on a second region of the liquid crystal panel; a data converter for converting a first video data having a first frame frequency into a second video data having a second frame frequency, which is higher than the first frame frequency; a backlight unit having a first lamp group with at least two lamps for respectively irradiating light onto sub-regions of the first region and a second lamp group with at least two lamps respectively irradiating light on sub-regions of the second region; and a driver for driving the gate lines, the first data lines and the second data lines in accordance with the second video data and for driving the first and second lamp groups at the second frame frequency so that the lamps of the first lamp group are sequentially turned on and off in synchronization with the lamps of the second lamp group.

Claims

1. A liquid crystal display device, comprising:

a liquid crystal panel having first data lines crossing gate lines on a first region of the liquid crystal panel and second data lines crossing the gate lines on a second region of the liquid crystal panel;

a data converter for converting a first video data having a first frame frequency into a second video data having a second frame frequency, which is higher than the first frame frequency;

a backlight unit having a first lamp group with at least two lamps for respectively irradiating light onto sub-regions of the first region and a second lamp group with at least two lamps respectively irradiating light on sub-regions of the second region; and

a driver for driving the gate lines, the first data lines and the second data lines in accordance with the second video data and for driving the first and second lamp groups at the second frame frequency so that the lamps of the first lamp group are sequentially turned on and off in synchronization with the lamps of the second lamp group.

2. The liquid crystal display device according to claim 1, wherein the driver includes:

a gate driver for simultaneously driving the gate lines on the first and second regions so that the gate lines on the second region are sequentially enabled in synchronization with the gate lines on the first region;

a first data driver for driving the first data lines on the first region;

a second data driver for driving the second data lines on the second region; and

a timing controller responsive to the second video data for controlling the gate driver, the first data driver and the second data driver and enabling the lamps of the first and second lamp groups to be sequentially turned on and off in synchronization with each other.

3. The liquid crystal display device according to claim 2, wherein the backlight unit includes at least two lamp drivers being controlled by the timing controller and generating lamp driving voltages for enabling the lamps of the first and second lamp groups to be sequentially driven in synchronization with each other.

4. The liquid crystal display device according to claim 3, wherein the lamp driving voltages have different duty cycles.

5. The liquid crystal display device according to claim 4, wherein the second frame frequency is at least twice the first frame frequency.

6. A liquid crystal display device, comprising:

a liquid crystal panel having gate lines and data lines crossing each other;

a backlight unit having a first lamp group with at least two lamps for divisionally irradiating light on a first region of the liquid crystal panel and a second lamp group with at least two lamps divisionally irradiating light on a second region of the liquid crystal panel; and

a driver for driving the gate lines and data lines in accordance with a video data having a first frame frequency and for controlling the first and second lamp groups to be simultaneously driven at a second frame frequency higher than the first frame frequency so that the lamps of the first lamp group are sequentially turned on and off in synchronization with the lamps of the second lamp group.

7. The liquid crystal display device according to claim 6, wherein the driver includes:

a gate driver for driving the gate lines;

a data driver for driving the data lines; and

a timing controller responsive to the video data having the first frame frequency for controlling the gate driver and the date driver and enabling the lamps of the first and second lamp groups to be sequentially turned on and off in synchronization with each other.

8. The liquid crystal display device according to claim 7, wherein the backlight unit includes at least two lamp drivers being controlled by the timing controller and generating lamp driving voltages for enabling the lamps of the first and second lamp groups to be sequentially driven in synchronization with each other.

9. The liquid crystal display device according to claim 8, wherein the lamp driving voltages have different duty cycles.

10. The liquid crystal display device according to claim 6, wherein the second frame frequency is at least twice the first frame frequency.

11. The liquid crystal display device according to claim 6, wherein the gate lines include:

first gate lines crossing the data lines on a third region occupying parts of the first and second regions; and

second gate lines crossing the data lines on a fourth region occupying remaining parts of the first and second regions.

12. The liquid crystal display device according to claim 11, wherein the driver includes:

a first gate driver for driving the first gate lines;

a second gate driver for driving the second gate lines in synchronization with the first gate lines;

a data driver for driving the data lines; and

a timing controller responsive the video data having the first frame frequency for controlling the first and second gate drivers and the date driver and enabling the lamps of the first and second lamp groups to be sequentially turned on and off in synchronization with each other.

13. The liquid crystal display device according to claim 12, wherein the backlight unit includes at least two lamp drivers being controlled by the timing controller and generating lamp driving voltages for enabling the lamps of the first and second lamp groups to be sequentially driven in synchronization with each other.

14. The liquid crystal display device according to claim 13, wherein the lamp driving voltages have different duty cycles.

15. The liquid crystal display device according to claim 11, wherein the second frame frequency is at least twice the first frame frequency.

16. A liquid crystal display device, comprising:

a liquid crystal panel having first data lines crossing gate lines on a first region of the liquid crystal panel and second data lines crossing the gate lines on a second region of the liquid crystal panel;

a backlight unit having a first lamp group with at least two lamp for respectively irradiating light onto sub-regions of the first region and a second lamp group with at least two lamps respectively irradiating light on sub-regions of the second region; and

a driver for driving the gate lines and the data lines to simultaneously write data voltages of a video data to liquid crystal cells of the first region and liquid crystal cells of the second region in each frame in line by line fashion, and for driving the first and second lamp groups so that the at least two lamps of the first lamp group are sequentially turned on and off once in synchronization with the at least two lamps of the second lamp group.

17. The liquid crystal display device according to claim 16, wherein the gate lines on the first region and the gate lines on the second region are sequentially enabled in each two period of a horizontal sync signal in synchronization with each other.

18. The liquid crystal display device according to claim 17, wherein the driver includes:

a gate driver for simultaneously driving the gate lines on the first and second regions so that the gate lines on the second region are sequentially enabled in synchronization with the gate lines on the first region;

a first data driver for driving the first data lines on the first region;

a second data driver for driving the second data lines on the second region; and

a timing controller responsive to the video data for controlling the gate driver, the first data driver and the second data driver and enabling the lamps of the first and second lamp groups to be sequentially turned on and off in synchronization with each other.

19. The liquid crystal display device according to claim 18, wherein the backlight unit includes at least two lamp drivers being controlled by the timing controller and generating lamp driving voltages for enabling the lamps of the first and second lamp groups to be sequentially driven in synchronization with each other.

20. The liquid crystal display device according to claim 18, wherein the lamp driving voltages have different duty cycles.

21. A liquid crystal display device, comprising:

a liquid crystal panel having first data lines crossing gate lines on a first region of the liquid crystal panel and second data lines crossing the gate lines on a second region of the liquid crystal panel;

a backlight unit having a first lamp group with at least two lamps for respectively irradiating light onto sub-regions of the first region and a second lamp group with at least two lamps respectively irradiating light on sub-regions of the second region; and

a driver for operating the gate lines and the data lines to simultaneously write data voltages of a video data to liquid crystal cells of the first region and liquid crystal cells of the second region in each frame in a line by line manner, and for driving the first and second lamp groups so that the lamps of the first and second lamp groups are turned on and off at time when an alignment saturation period elapses after the data voltages are written to liquid crystal cells of the corresponding sub-regions.

22. The liquid crystal display device according to claim 21, wherein the gate lines on the first region and the gate lines on the second region are sequentially enabled in each period of one horizontal sync signal in synchronization with each other.

23. The liquid crystal display device according to claim 22, wherein the gate lines on the first region and the gate lines on the second region are sequentially enabled once in synchronization with each other during a half frame period in each frame.

24. The liquid crystal display device according to claim 23, wherein the driver includes:

a gate driver for simultaneously driving the gate lines on the first and second regions so that the gate lines on the second region are sequentially enabled in synchronization with the gate lines on the first region;

a first data driver for driving the first data lines on the first region;

a second data driver for driving the second data lines on the second region; and

a timing controller responsive to the video data for controlling the gate driver, the first data driver and the second data driver and enabling the lamps of the first and second lamp groups to be sequentially turned on and off in synchronization with each other.

25. The liquid crystal display device according to claim 24, wherein the backlight unit includes at least two lamp drivers being controlled by the timing controller and generating lamp driving voltages for enabling the lamps of the first and second lamp groups to be sequentially driven in synchronization with each other.

26. The liquid crystal display device according to claim 25, wherein the lamp driving voltages have different duty cycles.

27. A liquid crystal display device, comprising:

a liquid crystal panel having gate lines and data lines crossing each other;

a backlight unit having a first lamp group with at least two lamps for divisionally irradiating light on a first region of the liquid crystal panel and a second lamp group with at least two lamps for divisionally irradiating light on a second region of the liquid crystal panel; and

a driver for driving the gate lines and data lines to sequentially write data voltages of a video data to liquid crystal cells of the liquid crystal panel in each frame in line by line manner, and for controlling the first and second lamp groups to be sequentially turned on and off once in synchronization with each other.

28. The liquid crystal display device according to claim 27, wherein the driver includes:

a gate driver for sequentially driving the gate lines once in each frame;

a data driver for driving the data lines; and

a timing controller responsive to the video data for controlling the gate driver and the date driver and enabling the lamps of the first and second lamp groups to be sequentially turned on and off once in synchronization with each other.

29. The liquid crystal display device according to claim 28, wherein the backlight unit includes at least two lamp drivers being controlled by the timing controller and generating lamp driving voltages for enabling the lamps of the first and second lamp groups to be sequentially driven in synchronization with each other.

30. The liquid crystal display device according to claim 29, wherein the lamp driving voltages have different duty cycles.

31. A method of driving a liquid crystal display device with a liquid crystal panel having first data lines crossing gate lines on a first region of the liquid crystal panel, and second data lines crossing the gate lines on a second region of the liquid crystal panel, comprising:

converting a first video data having a first frame frequency into a second video data having a second frame frequency higher than the first frame frequency;

driving the gate lines, the first and second data lines in accordance with the second video data; and

controlling the first and second lamp groups to turn-on and turn-off simultaneously at the second frame frequency, the first lamp groups having at least two lamps for a first region and the second lamp group having at least two lamps for the second region.

32. The method according to claim 31, wherein the second frame frequency is at least twice the first frame frequency.

33. A method of driving a liquid crystal display device with a liquid crystal panel having gate lines and data lines crossing each other, comprising:

driving the gate lines and data lines in accordance with a video data having a first frame frequency; and

controlling the first and second lamp groups to turn-on and turn-off simultaneously at a second frame frequency higher than the first frame frequency, the first lamp group having at least two lamps for a first region of the liquid crystal panel and the second lamp group having at least two lamps for a second region of the liquid crystal panel.

34. The method according to claim 33, wherein the second frame frequency is at least twice the first frame frequency.

35. The method according to claim 35, wherein the gate lines include:

first gate lines crossing the data lines on a third region occupying parts of the first and second regions; and

second gate lines crossing the data lines on a fourth region occupying remaining parts of the first and second regions.

36. A method for controlling a liquid crystal display device having a liquid crystal panel with first data lines crossing gate lines on a first region and second data lines crossing the gate lines on a second region, at least two first lamps partially corresponding to the first region of the liquid crystal panel, and at least two second lamps partially corresponding to the second region of the liquid crystal panel, the method comprising:

driving the gate lines and data lines to simultaneously write data voltages of a video data to liquid crystal cells of the first region and liquid crystal cells of the second region in line by line fashion; and

turning on and off once the first lamps together with the second lamps by one pair at a time.

37. The method according to claim 36, wherein the gate lines on the first region and the gate lines on the second region are sequentially enabled in synchronization with each other in each two period of a horizontal sync signal.

38. A method for controlling a liquid crystal display device having a liquid crystal panel with first data lines crossing gate lines on a first region and second data lines crossing the gate lines on a second region, at least two first lamps partially corresponding to the first region of the liquid crystal panel, and at least two second lamps partially corresponding to the second region of the liquid crystal panel, the method comprising:

driving the gate lines and data lines to simultaneously write data voltages of a video data to liquid crystal cells of the first region and liquid crystal cells of the second region in a line by line manner; and

driving the first and second lamps so that the lamps of the first and second lamps are turned on and off at time when an alignment saturation period elapses after the data voltages are written to liquid crystal cells on the liquid crystal panel.

39. The method according to claim 38, wherein the driving of the gate lines and the data lines includes enabling sequentially the gate lines on the first region and the gate lines on the second region in synchronization with each other in each period of a horizontal sync signal, and the driving of the lamps includes turning on and off the first and second lamps once in each frame.

40. The method according to claim 39, wherein the gate lines on the first region and the gate lines on the second region are sequentially enabled once in synchronization with each other during half frame period in each frame.