Display device to apply compensation data and driving method thereof

1. A display device, comprising:

a display panel including a pixel connected to a gate line and a data line, the pixel including a liquid crystal capacitor;

a data driver to apply a data voltage to the data line;

a gate driver to apply a gate-on voltage to the gate line; and

a signal controller to obtain compensation data and normal data based on a discrimination signal indicating that input data is for a still image, the signal controller to apply the compensation data and normal data to the pixel during different periods of a frame, wherein:

the signal controller is not to obtain compensation data and is to obtain normal data when the discrimination signal indicates that input data is for a moving image, the normal data to be applied once when the moving image is to be displayed, and

the compensation data has a value that reduces a difference of operation characteristics of liquid crystal molecules in the liquid crystal capacitor when a data voltage for the display panel changes between different polarities.

2. The display device as claimed in claim 1 , further comprising:

a lookup table to store the compensation data,

wherein the signal controller accesses the compensation data from the lookup table.

3. The display device as claimed in claim 1 , wherein:

the gate driver applies the gate-on voltage to the gate line twice during the frame, and

the data driver applies a compensation data voltage based on the compensation data when the gate-on voltage is applied in a first period of the frame, and applies a normal data voltage based on the normal data when the gate-on voltage is applied during a second period of the frame.

4. The display device as claimed in claim 3 , wherein the gate-on voltage, compensation data voltage, and normal data voltage are applied based on a vertical synchronization start signal.

5. The display device as claimed in claim 3 , wherein the compensation data voltage has a gray level less than or equal to a gray level of the normal data voltage.

6. The display device as claimed in claim 1 , wherein the compensation data includes

first compensation data when the polarity of the data voltage is changed from a positive polarity to a negative polarity, and

second compensation data when the polarity of the data voltage is changed from a negative polarity to a positive polarity.

7. The display device as claimed in claim 6 , wherein the normal data includes negative normal data and positive normal data.

8. The display device as claimed in claim 7 , wherein:

the negative normal data is applied when the first compensation data is applied, and

the positive normal data is applied when the second compensation data is applied.

9. A method of driving a display device, the method comprising:

receiving input data;

obtaining compensation data and normal data for the input data when a discrimination signal indicates that the input data is for a still image;

applying the compensation data to a pixel during a first period of a frame; and

applying the normal data to the pixel during a second period of the frame, wherein the compensation data is not obtained and the normal data is obtained when the discrimination signal indicates that the input data is for a moving image, the normal data to be applied once when the moving image is to be displayed, and wherein the compensation data has a value which reduces a difference of operation characteristics of liquid crystal molecules in a liquid crystal capacitor of the pixel when a data voltage for a display panel changes between different polarities.

10. The method as claimed in claim 9 , wherein the compensation data is applied based on a first vertical synchronization start signal for the frame, the method further comprising:

applying a gate-on voltage to a gate line based on a first vertical synchronization start signal; and

transmitting a compensation data voltage corresponding to the compensation data to the pixel through a data line.

11. The method as claimed in claim 10 , wherein the normal data is applied to the pixel based on a second vertical synchronization start signal, the method further comprising:

applying the gate-on voltage to the gate line based on the second vertical synchronization start signal, the normal data voltage transmitted through the data line.

12. The method as claimed in claim 9 , wherein a compensation data voltage corresponding to the compensation data has a gray level lower than or equal to a gray level of a normal data voltage corresponding to the normal data.

13. An apparatus for a display device, comprising:

a signal line to receive input data; and

a controller to apply compensation data to a pixel during a first period of a frame and to apply image data to the pixel during a second period of the frame, the compensation data and the image data to be applied based on a discrimination signal indicating that the input data is for a still image, wherein:

the controller is not to obtain compensation data and is to obtain normal data when the discrimination signal indicates that input data is for a moving image, the normal data to be applied once when the moving image is to be displayed, and

the compensation data has a value that reduces asymmetry between variation curves generated when a data voltage for a display panel including the pixel changes between different polarities.

14. The apparatus as claimed in claim 13 , wherein the asymmetry between the variation curves reduces flicker in the display panel.

15. The apparatus as claimed in claim 13 , wherein the controller applies the compensation data based on a first start signal and applies the image data based on a second start signal.

16. The apparatus as claimed in claim 13 , wherein the controller generates the compensation data based on the input data.

17. The apparatus as claimed in claim 13 , wherein the controller retrieves the compensation data from a lookup table based on one or more parameters.

18. The apparatus as claimed in claim 13 , wherein the value of the compensation data reduces a difference of operation characteristics of liquid crystal molecules in a liquid crystal capacitor included in the pixel when the data voltage changes between different polarities.