Display device and driving method thereof

1. A display device comprising:

a gray converter which adds compensation grays to input grays to provide output grays;

a data driver which provides data voltages corresponding to the output grays; and

a display panel which includes pixels which receives the data voltages,

wherein the gray converter includes:

a voltage domain converter which converts the input grays into conversion grays;

a memory which outputs previous conversion grays; and

a compensation gray calculator which calculates the compensation grays based on the conversion grays,

wherein the conversion grays correspond to a current pixel row, and the previous conversion grays correspond to two previous pixel rows,

the compensation gray calculator includes a lookup table in which compensation values corresponding to some of the previous conversion grays and some of the conversion grays are recorded, and

the compensation gray calculator calculates first interpolated values for some of the pixels by interpolating the compensation values.

2. The display device of claim 1 , wherein

the pixels include first pixels and second pixels,

each of the first pixels is connected to a data line disposed in a first direction from the each of the first pixels,

each of the second pixels is connected to a data line disposed in a second direction from the each of the second pixels, and

the first direction is opposite to the second direction.

3. The display device of claim 2 , further comprising

a data distributor connected to the data driver through data output lines and connected to the pixels through the data lines,

wherein the number of the data output lines is smaller than the number of the data lines.

4. The display device of claim 2 , wherein

the compensation gray calculator calculates second interpolated values for others of the pixels by interpolating the first interpolated values.

5. The display device of claim 4 , wherein

the compensation gray calculator converts the second interpolated values into values in a gray domain to provide the values in the gray domain as the compensation grays.

6. The display device of claim 4 , wherein

the gray converter further includes a maximum luminance gain provider which provides a maximum luminance gain based on a maximum luminance,

wherein the compensation gray calculator scales the second interpolated values according to the maximum luminance gain, and converts the scaled second interpolated values into values in a gray domain to provide the values in the gray domain as the compensation grays.

7. The display device of claim 6 , wherein

the maximum luminance gain provider increases the maximum luminance gain as the maximum luminance increases.

8. The display device of claim 4 , wherein

the gray converter further includes a connection gain provider which provides connection gains for the first pixels, and

the compensation gray calculator scales the second interpolated values according to the connection gains, and converts the scaled second interpolated values into values in a gray domain to provide the values in the gray domain as the compensation grays.

9. The display device of claim 8 , wherein

the connection gain provider does not provide connection gains for the second pixels.

10. The display device of claim 4 , wherein

the gray converter further includes an area gain provider which provides area gains based on positions of the pixels, and

the compensation gray calculator scales the second interpolated values according to the area gains, and converts the scaled second interpolated values into values in a gray domain to provide the values in the gray domain as the compensation grays.

11. The display device of claim 10 , wherein

the display panel is divided into a first area, a second area, and a third area;

the first area includes pixels at a first pixel density;

the second area and the third area include pixels at a second pixel density higher than the first pixel density;

the pixels in the second area and the pixels in the first area are connected to same data lines; and

the area gain provider provides a first area gain of the area gains for the pixels in the first area, and a second area gain of the area gains for the pixels in the second area.

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

converting input grays into conversion grays in a voltage domain;

calculating compensation grays based on the conversion grays;

providing output grays by adding the compensation grays to the input grays; and

providing data voltages corresponding to the output grays to pixels,

wherein the calculating of the compensation grays includes:

referring to a lookup table which records compensation values corresponding to some of previous conversion grays and some of the conversion grays, where the conversion grays correspond to a current pixel row, and the previous conversion grays correspond to two previous pixel rows; and

calculating first interpolated values by interpolating the compensation values for some of the pixels.

13. The driving method of the display device of claim 12 , further comprising

calculating second interpolated values by interpolating the first interpolated values for others of the pixels.

14. The driving method of the display device of claim 13 , further comprising

providing the second interpolated values as the compensation grays.

15. The driving method of the display device of claim 13 , further comprising

scaling the second interpolated values according to a maximum luminance gain which increases as a maximum luminance increases; and converting the scaled second interpolated values into values in a gray domain to provide the values in the gray domain as the compensation grays.