Display device including four color subpixels and method of driving the same

1. A display device, comprising:

a timing controlling part for generating a three color image data for a first pixel, a data control signal and a gate control signal using an image signal and a plurality of timing signals, generating a first four color data having a white gray level data greater than 0 using the three color image data for the first pixel and a second four color data having the white gray level data of 0 using the three color image data for the first pixel, and generating a four color image data using a combination of the first and second four color data;

a data driving part for generating a data signal using the four color image data and the data control signal;

a gate driving part for generating a gate signal using the gate control signal; and

a display panel including a second pixel having red, green, blue and white subpixels and displaying an image using the data signal and the gate signal,

wherein each of the first and second four color data includes red, green, blue and white gray level data,

wherein for each of the first and second four color data: at least one of the red, green and blue gray level data is 0, and at least one of the red, green and blue gray level data is greater than 0.

2. The display device of claim 1 , wherein the display panel steadily displays a white in a residual image area using the data signal and the gate signal corresponding to the four color image data.

3. The display device of claim 2 , wherein the residual image area corresponds to a top 10% of a histogram of a cumulative luminance average of the pixel.

4. The display device of claim 1 , wherein the timing controlling part is configured to generate the four color image data by adding first and second contributing components, and

wherein the first contributing component is a product of the first four color data and a value obtained by subtracting a luminance ratio from 1, and the second contributing component is a product of the second four color data and the luminance ratio.

5. The display device of claim 4 , wherein the luminance ratio is updated according to a change of cumulative luminance averages of the red, green and blue gray level data of the four color image data of the residual image area and the red, green and blue gray level data of the four color image data of an adjacent area other than the residual image area.

6. The display device of claim 1 , wherein the timing controlling part is configured to generate the first four color data as the four color image data for a first time period, and generate the second four color data as the four color image data for a second time period alternating with the first time period.

7. The display device of claim 6 , wherein the a time ratio of the first and second time periods is updated according to a change of cumulative luminance averages of the red, green and blue gray level data of the four color image data of the residual image area and the red, green and blue data of the four color image data of an adjacent area other than the residual image area.

8. A method of driving a display device, comprising:

generating a three color image data for a first pixel, a data control signal and a gate control signal using an image signal and a plurality of timing signals,

generating a first four color data having a white gray level data greater than 0 using the three color image data for the first pixel and a second four color data having the white gray level data of 0 using the three color image data for the first pixel, and generating a four color image data using a combination of the first and second four color data;

generating a data signal using the four color image data and the data control signal;

generating a gate signal using the gate control signal; and

displaying an image using the data signal and the gate signal in a display panel including a second pixel having red, green, blue and white subpixels,

wherein each of the first and second four color data includes red, green, blue and white gray level data,

wherein for each of the first and second four color data: at least one of the red, green and blue gray level data is 0, and at least one of the red, green and blue gray level data is greater than 0.

9. The method claim 8 , wherein generating the four color image data comprises:

calculating a first contributing component by multiplying the first four color data and a value obtained by subtracting a luminance ratio from 1 and calculating a second contributing component by multiplying the second four color data and the luminance ratio; and

generating a sum of the first and second contributing components as the four color image data.

10. The method of claim 8 , wherein generating the four color image data comprises:

generating the first four color data as the four color image data for a first time period, and

generating the second four color data as the four color image data for a second time period alternating with the first time period.

11. The method of claim 8 , wherein the display panel steadily displays a white in a residual image area using the data signal and the gate signal corresponding to the four color image data.

12. The method of claim 11 , wherein the residual image area corresponds to a top 10% of a histogram of a cumulative luminance average of the pixel.

13. The method of claim 9 , wherein the luminance ratio is updated according to a change of cumulative luminance averages of the red, green and blue gray level data of the four color image data of a residual image area and the red, green and blue gray level data of the four color image data of an adjacent area other than the residual image area.

14. The method of claim 10 , wherein the a time ratio of the first and second time periods is updated according to a change of cumulative luminance averages of the red, green and blue gray level data of the four color image data of a residual image area and the red, green and blue data of the four color image data of an adjacent area other than the residual image area.