Display device with different driving frequencies for still and moving images and method of driving the same

1. A display device comprising:

a display panel including a plurality of pixels; and

a display panel driver configured to drive the display panel, wherein the display panel driver is configured to receive input image data, to drive the display panel at a first driving frequency when the input image data corresponds to a moving image, and to select a flicker lookup table from among a plurality of flicker lookup tables based on the first driving frequency and drive the display panel at a second driving frequency based on the selected flicker lookup table when the input image data corresponds to a still image,

wherein each of the plurality of flicker lookup tables stores candidates for the second driving frequency, which respectively correspond to grayscales of the input image data that is driven at the first driving frequency, and

wherein the display panel driver determines one of the candidates as the second driving frequency based on the selected flicker lookup table.

2. The display device of claim 1 , wherein the each of the plurality of flicker lookup tables further stores flicker values respectively corresponding to the candidates which respectively correspond to the grayscales of the input image data that is driven at the first driving frequency.

3. The display device of claim 1 , wherein the first driving frequency is higher than the second driving frequency.

4. The display device of claim 1 , wherein the display panel driver includes:

an image determiner configured to receive the input image data to determine whether the input image data corresponds to the moving image or the still image;

a storage unit configured to store the plurality of flicker lookup tables;

a selector configured to select one of the plurality of flicker lookup tables based on the first driving frequency; and

a frequency determiner configured to determine the second driving frequency based on the selected flicker lookup table.

5. The display device of claim 4 , wherein the selector selects one of the plurality of flicker lookup tables according to the first driving frequency.

6. The display device of claim 4 , wherein the selector selects one of the plurality of flicker lookup tables according to a frequency band in which the first driving frequency is included.

7. The display device of claim 4 , wherein the selector receives the first driving frequency from an external device.

8. The display device of claim 4 , wherein the selector calculates the first driving frequency based on the input image data.

9. The display device of claim 8 , wherein the selector calculates the first driving frequency by counting a reference clock signal that is input during an active period of a vertical synchronization signal.

10. The display device of claim 1 , wherein the display panel driver stores the plurality of flicker lookup tables during a manufacturing process of the display device.

11. The display device of claim 1 , wherein the display panel driver stores a reference flicker lookup table corresponding to a reference driving frequency during a manufacturing process of the display device and generates the plurality of flicker lookup tables by using a conversion coefficient for converting the reference flicker lookup table.

12. A method of driving a display device comprising:

receiving input image data;

determining whether the input image data corresponds to a moving image or a still image;

driving a display panel at a first driving frequency when the input image data corresponds to the moving image;

selecting a flicker lookup table from among a plurality of flicker lookup tables based on the first driving frequency and determining a second driving frequency based on the selected flicker lookup table when the input image data corresponds to the still image; and

driving the display panel at the second driving frequency when the input image data corresponds to the still image,

wherein each of the plurality of flicker lookup tables stores candidates for the second driving frequency, which respectively correspond to grayscales of the input image data that is driven at the first driving frequency, and

wherein one of the candidates is determined as the second driving frequency based on the selected flicker lookup table.

13. The method of claim 12 , wherein the each of the plurality of flicker lookup tables further stores flicker values respectively corresponding to candidates which respectively correspond to the grayscales of the input image data that is driven at the first driving frequency.

14. The method of claim 12 , wherein the first driving frequency is higher than the second driving frequency.

15. The method of claim 12 , wherein the selected flicker lookup table is selected according to the first driving frequency.

16. The method of claim 12 , wherein the selected flicker lookup table is selected according to a frequency band in which the first driving frequency is included.

17. The method of claim 12 , wherein the first driving frequency is provided from an external device.

18. The method of claim 12 , wherein the first driving frequency is calculated based on the input image data.

19. The method of claim 18 , wherein the first driving frequency is calculated by counting a reference clock signal that is input during an active period of a vertical synchronization signal.

20. The method of claim 12 , wherein the plurality of flicker lookup tables are generated by using a conversion coefficient for converting a reference flicker lookup table corresponding to a reference driving frequency.

21. A method of driving a display device comprising:

receiving input image data;

determining that the input image data corresponds to a still image;

looking up an intermediary second driving frequency in a reference flicker lookup table according to a first driving frequency;

looking up a conversion coefficient in a conversion coefficient lookup table according to the first driving frequency;

determining a second driving frequency by multiplying the intermediary second driving frequency by the conversion coefficient; and

driving a display panel at the second driving frequency.