Light emitting display device and driving method thereof

1. A light emitting display device comprising:

a display panel including a red sub-pixel, a green sub-pixel, a blue sub-pixel and a white sub-pixel;

a driver configured to drive the display panel; and

a timing controller configured to control the driver,

wherein W peak luminance derived by the white sub-pixels is higher than a sum of RGB peak luminances derived by the red sub-pixel, the green sub-pixel and the blue sub-pixel when the display panel displays an image, and

wherein the timing controller calculates at least one of a first average picture level that does not take a chroma component into account and a second average picture level taking the chroma component into account according to an input image at the time of calculating an average picture level for an image to be displayed on the display panel.

2. The light emitting display device of claim 1 , wherein the timing controller generates a peak luminance control signal for controlling the W peak luminance to be higher than the sum of the RGB peak luminances based on the second average picture level.

3. The light emitting display device of claim 1 , wherein the second average picture level is calculated based on the following formula,

second average picture level=(total pixel sum (MAX(R,G,B)/255×((MAX(R,G,B)−(1−chroma gain))×MIN(R,G,B))/MAX(R,G,B)))/total pixel count)×100,

wherein the total pixel sum is a sum of all pixels, MAX(R,G,B) is a maximum value of RGB data signals, MIN(R,G,B) is a minimum value of the RGB data signals, the chroma gain is a gain value according to a chroma component, and the total pixel count is a count value of all pixels.

4. The light emitting display device of claim 1 , wherein the timing controller generates a peak luminance control signal for independently controlling W luminance derived by the white sub-pixels and independently controlling RGB luminances derived by the red sub-pixel, the green sub-pixel and the blue sub-pixel, respectively.

5. The light emitting display device of claim 1 , wherein the timing controller generates a peak luminance control signal for decreasing W luminance derived by the white sub-pixels without changing RGB luminances derived by the red sub-pixel, the green sub-pixel and the blue sub-pixel when there is a predetermined number of white images in an input image.

6. The light emitting display device of claim 1 , wherein the timing controller generates a peak luminance control signal for increasing W luminance derived by the white sub-pixels without changing RGB luminances derived by the red sub-pixel, the green sub-pixel and the blue sub-pixel when there is a predetermined number of white images in an input image.

7. The light emitting display device of claim 1 , wherein the timing controller generates a peak luminance control signal for decreasing W luminance derived by the white sub-pixels instead of increasing RGB luminances derived by the red sub-pixel, the green sub-pixel and the blue sub-pixel when there is a predetermined number of white images in an input image.

8. The light emitting display device of claim 1 , wherein the timing controller generates a peak luminance control signal for increasing W luminance derived by the white sub-pixels instead of decreasing RGB luminances derived by the red sub-pixel, the green sub-pixel and the blue sub-pixel when there is a predetermined amount of white images in an input image.

9. A method of driving a light emitting display device including a display panel including a red sub-pixel, a green sub-pixel, a blue sub-pixel and a white sub-pixel, a driver for driving the display panel, and a timing controller for controlling the driver, the method comprising:

calculating at least one of a first average picture level that does not take a chroma component into account and a second average picture level taking a chroma component into account according to an input image; and

generating a peak luminance control signal based on the first average picture level or the second average picture level,

wherein W peak luminance derived by the white sub-pixels is higher than a sum of RGB peak luminances derived by the red sub-pixel, the green sub-pixel and the blue sub-pixel when the display panel displays an image.

10. The method of claim 9 , wherein the second average picture level is calculated based on the following formula,

second average picture level=(total pixel sum (MAX(R,G,B)/255×((MAX(R,G,B)−(1−chroma gain))×MIN(R,G,B))/MAX(R,G,B)))/total pixel count)×100,

wherein the total pixel sum is a sum of all pixels, MAX(R,G,B) is a maximum value of RGB data signals, MIN(R,G,B) is a minimum value of the RGB data signals, the chroma gain is a gain value according to a chroma component, and the total pixel count is a count value of all pixels.

11. A light emitting display device comprising:

a display panel including a red sub-pixel, a green sub-pixel, a blue sub-pixel and a white sub-pixel;

a driver configured to drive the display panel; and

a timing controller configured to control the driver, to calculate an average picture level taking a chroma component into account according to an input image, and to generate a peak luminance control signal for controlling W peak luminance derived by the white sub-pixels to be higher than a sum of RGB peak luminances derived by the red sub-pixel, the green sub-pixel and the blue sub-pixel based on the average picture level.

12. The light emitting display device of claim 11 , wherein the display panel displays an image in which W peak luminance is higher than a sum of RGB peak luminances in response to the peak luminance control signal.

13. The light emitting display device of claim 11 , wherein the average picture level is calculated based on the following formula,

average picture level=(total pixel sum (MAX(R,G,B)/255×((MAX(R,G,B)−(1−chroma gain))×MIN(R,G,B))/MAX(R,G,B)))/total pixel count)×100,

wherein the total pixel sum is a sum of all pixels, MAX(R,G,B) is a maximum value of RGB data signals, MIN(R,G,B) is a minimum value of the RGB data signals, the chroma gain is a gain value according to a chroma component, and the total pixel count is a count value of all pixels.