Method and apparatus for displaying an image
In order to display an image in a display device, in which a plurality of sub pixels within a unit pixel receives driving power from one driving power line, a driving voltage stability weak pattern is detected by analyzing image data. When the input image is determined as the driving voltage stability weak pattern, a white balance correction gain of each sub pixel is decreased while a ratio among the white balance correction gains of the sub pixels is maintained. Target luminance for displaying the input image is changed. A voltage level of the driving power is change in accordance with the changed target luminance.
1. A method of displaying an image in a display device, in which a plurality of sub pixels within a unit pixel receives driving power from one driving power line, the method comprising:
determining a white balance correction gain for each sub pixel of the plurality of sub pixels based on the driving power and an original operation point of each sub pixel;
analyzing image data and detecting whether the image data correspond to a driving voltage stability weak pattern; and
when the image data is determined as the driving voltage stability weak pattern,
decreasing the white balance correction gain of each sub pixel while maintaining a ratio among the white balance correction gains of the sub pixels;
changing a target luminance for displaying the image data; and
changing a voltage level of the driving power in accordance with changed target luminance,
wherein the white balance correction gain of each sub pixel is a gain to adjust an emission duty of each sub pixel in a frame.
2. The method as claimed in claim 1 , wherein detecting the driving voltage stability weak pattern includes:
measuring a voltage change of the driving power supplied to the sub pixels within the unit pixel while displaying the image data, and
determining the image data as the driving voltage stability weak pattern when a range of the voltage change is equal to or larger than a predetermined specific value.
3. The method as claimed in claim 1 , wherein detecting the driving voltage stability weak pattern includes:
dividing the image data into a plurality of blocks; and
calculating a sum of an image load of each of the plurality of blocks; and
when a deviation to the sum of the image load calculated for each block is equal to or larger than a predetermined value, determining the image data as the driving voltage stability weak pattern.
4. The method as claimed in claim 1 , wherein decreasing the white balance correction gain of each sub pixel includes multiplying the white balance correction gains of the sub pixels and a same factor value.
5. The method as claimed in claim 4 , wherein an emission period, for which an emission device of each sub pixel emits light within one frame period, is decreased by decreasing the white balance correction gain.
6. The method as claimed in claim 4 , wherein the same factor value is a number larger than 0 and smaller than 1.
7. The method as claimed in claim 1 , wherein changing the target luminance for displaying the image data includes decreasing the target luminance generated by the image data.
8. The method as claimed in claim 7 , wherein changing the voltage level of the driving power in accordance with the changed target luminance includes decreasing the voltage level in accordance with the decreased target luminance.
9. The method as claimed in claim 1 , wherein the sub pixels include a red sub pixel, a green sub pixel, and a blue sub pixel.
10. A display device, comprising:
a display panel including a plurality of unit pixels, in which a plurality of sub pixels within the unit pixels receives driving power from a same driving power line;
a weak pattern detector to analyze image data, and determine whether the image data is a driving voltage stability weak pattern;
a white balance corrector to store a white balance correction gain for each sub pixel of the plurality of sub pixels based on the driving power and an original operation point of each sub pixel and, when the weak pattern detector detects the driving voltage stability weak pattern, change the white balance correction gain applied to each sub pixel and to change target luminance of the image data; and
a driving power adjustor to, when the white balance corrector outputs a change target luminance, change a voltage level applied to the driving power line within the display panel based on changed target luminance,
wherein the white balance correction gain of each sub pixel is a gain to adjust an emission duty of each sub pixel in a frame.
11. The display device as claimed in claim 10 , wherein the weak pattern detector detects the voltage level of the driving line while the image data is displayed on the display panel, and determines the image data as a driving voltage stability weak pattern when a variation range of the voltage level according to a time is equal to or larger than a predetermined specific value.
12. The display device as claimed in claim 10 , wherein the weak pattern detector divides the image data into a plurality of blocks, calculates a sum of an image data load for each of the plurality of blocks, and determines the image data as the driving voltage stability weak pattern when a deviation to the sum of the image data load for each block is equal to or larger than a predetermined specific value.
13. The display device as claimed in claim 10 , wherein the white balance corrector multiplies the white balance correction gains applied to the sub pixels and the same factor value.
14. The display device as claimed in claim 10 , wherein the white balance corrector decreases target luminance of the image data together with multiplying the white balance correction gains and a same factor value.
15. The display device as claimed in claim 14 , wherein the driving power adjustor changes a voltage level applied to the driving power line within the display panel based on the decreased target luminance.
16. The display device as claimed in claim 14 , wherein an emission period, for which an emission device of each sub pixel emits light within one frame period, is decreased by decreasing the white balance correction gain.
17. The display device as claimed in claim 16 , wherein emission periods are decreased by different amounts while maintaining a ratio among the white balance correction gains of the sub pixels.
18. The display device as claimed in claim 14 , wherein the same factor value is a number larger than 0 and smaller than 1.
19. The display device as claimed in claim 10 , wherein the white balance corrector, when the weak pattern detector detects the driving voltage stability weak pattern, is to decrease white balance correction gains of the sub pixels while maintaining a ratio among the white balance correction gains of the sub pixels.
20. The method as claimed in claim 1 , wherein decreasing the white balance correction gain includes decreasing emission periods by different amounts for the sub pixels.