Method of adjusting luminance of a backlight unit included in a liquid crystal display device

1. A method of adjusting luminance of a backlight unit included in a liquid crystal display device that performs inversion driving, the method comprising:

deriving a positive polarity histogram and a negative polarity histogram of an image frame based on image frame data, corresponding to the image frame, and a data polarity pattern for implementing the image frame;

deriving a luminance compensation value according to data polarity dominance of the image frame by analyzing the positive polarity histogram and the negative polarity histogram; and

applying the luminance compensation value to the luminance of the backlight unit during a portion of a time period of the image frame.

2. The method of claim 1 , wherein the portion of the time period of the image frame substantially begins at a start point of a blank period of the image frame and substantially ends at an end point of the blank period of the image frame.

3. The method of claim 1 , wherein the portion of the time period of the image frame substantially begins at a first point which is after a start point of a blank period of the image frame and substantially ends at an end point of the blank period of the image frame.

4. The method of claim 1 , wherein the portion of the time period of the image frame substantially begins at a start point of a blank period of the image frame and substantially ends at a second point which is before an end point of the blank period of the image frame.

5. The method of claim 1 , wherein the portion of the time period of the image frame substantially begins at a first point which is after a start point of a blank period of the image frame and substantially ends at a second point which is before an end point of the blank period of the image frame.

6. The method of claim 1 , wherein a weighted value is applied to the luminance compensation value differently for respective locations of a display panel included in the liquid crystal display device.

7. The method of claim 1 , wherein the luminance compensation value according to the data polarity dominance is derived by searching a preset mapping table.

8. The method of claim 7 , wherein the data polarity dominance is determined by comparing a sum of gray levels of positive polarity data with a sum of gray levels of negative polarity data.

9. A method of adjusting luminance of a backlight unit included in a liquid crystal display device that performs inversion driving, the method comprising:

deriving a positive polarity histogram and a negative polarity histogram of an image frame based on image frame data, corresponding to the image frame, and a data polarity pattern for implementing the image frame;

deriving a luminance compensation value according to data polarity dominance of the image frame by analyzing the positive polarity histogram and the negative polarity histogram;

applying the luminance compensation value to the luminance of the backlight unit from a start point of a blank period of the image frame to an end point of the blank period of the image frame;

measuring an elapsed time from the start point of the blank period of the image frame; and

applying first through (N)th additional luminance compensation values, where N is an integer greater than or equal to 1, to the luminance of the backlight unit, sequentially as the elapsed time reaches corresponding first through (N)th reference times.

10. The method of claim 9 , wherein the elapsed time is measured by counting data enable clocks or oscillator reference clocks.

11. The method of claim 9 , wherein a weighted value is applied to the luminance compensation value and the first through (N)th additional luminance compensation values differently for respective locations of a display panel included in the liquid crystal display device.

12. The method of claim 9 , wherein the luminance compensation value according to the data polarity dominance is derived by searching a preset mapping table.

13. The method of claim 12 , wherein the data polarity dominance is determined by comparing a sum of gray levels of positive polarity data with a sum of gray levels of negative polarity data.

14. A method of adjusting luminance of a backlight unit included in a liquid crystal display device that performs inversion driving, the method comprising:

deriving a positive polarity histogram and a negative polarity histogram of an image frame based on image frame data, corresponding to the image frame, and a data polarity pattern for implementing the image frame;

deriving a luminance compensation value according to data polarity dominance of the image frame by analyzing the positive polarity histogram and the negative polarity histogram; and

applying the luminance compensation value to the luminance of the backlight unit during a portion of a time period of the image frame and a portion of a time period of a next image frame following the image frame.

15. The method of claim 14 , wherein the portion of the time period of the image frame substantially begins at a start point of a blank period of the image frame and substantially ends at an end point of the blank period of the image frame.

16. The method of claim 14 , wherein the portion of the time period of the image frame substantially begins at a first point which is after a start point of a blank period of the image frame and substantially ends at an end point of the blank period of the image frame.

17. The method of claim 14 , wherein the portion of the time period of the next image frame substantially begins at a start point of an active period of the next image frame and substantially ends at a second point which is before an end point of the active period of the next image frame.

18. The method of claim 14 , wherein a weighted value is applied to the luminance compensation value differently for respective locations of a display panel included in the liquid crystal display device.

19. The method of claim 14 , wherein the luminance compensation value according to the data polarity dominance is derived by searching a preset mapping table.

20. The method of claim 19 , wherein the data polarity dominance is determined by comparing a sum of gray levels of positive polarity data with a sum of gray levels of negative polarity data.