Display device and method of driving the same
A display device includes a data driver which outputs a data voltage of a positive polarity or a negative polarity to a data line based on the polarity control signal by a horizontal period, and a number of a positive horizontal period, in which the data voltage of the positive polarity is outputted to the data line, in a frame period is different from a number of a negative horizontal period, in which the data voltage of the negative polarity is outputted to the data line, in the frame period when the frame image data satisfy a condition of an afterimage pattern.
1. A display device comprising:
a display panel including a pixel connected to a data line and a gate line;
an image data analyzer which analyzes whether frame image data satisfy a condition of an afterimage pattern;
a polarity signal controller which generates a polarity control signal to control a polarity of a data voltage applied to the data line to be a positive polarity or a negative polarity with respect to a reference voltage; and
a data driver which outputs the data voltage of the positive polarity or the negative polarity to the data line based on the polarity control signal by a horizontal period,
wherein a number greater than zero of a positive horizontal period, in which the data voltage of the positive polarity is outputted to the data line, in a frame period is different from a number greater than zero of a negative horizontal period, in which the data voltage of the negative polarity is outputted to the data line, in the same frame period when the frame image data satisfy the condition of the afterimage pattern.
2. The display device of claim 1 , wherein the number of the negative horizontal period in the frame period is less than the number of the positive horizontal period in the frame period when the frame image data satisfy the condition of the afterimage pattern.
3. The display device of claim 1 , wherein a difference between the number of the negative horizontal period in the frame period and the number of the positive horizontal period in the frame period increases when a charge rate difference between the data voltages of the positive polarity and the negative polarity increases.
4. The display device of claim 1 , wherein the number of the negative horizontal period in the frame period and the number of the positive horizontal period in the frame period is determined based on an offset of the reference voltage by a kickback.
5. The display device of claim 2 , wherein the number of the negative horizontal period in the frame period is equal to the positive horizontal period in the frame period when the frame image data do not satisfy the condition of the afterimage pattern.
6. The display device of claim 1 , wherein the polarity signal controller generates a first polarity control signal to control the polarity of the data voltage based on a first polarity pattern, in which a polarity of the data voltage is predetermined for every horizontal period, and a second polarity control signal to control the polarity of the data voltage based on a second polarity pattern which is inverted with the first polarity pattern.
7. The display device of claim 6 , wherein the polarity signal controller changes the first polarity control signal and the second polarity control signal from one to the other by a predetermined horizontal period, when the frame image data satisfy the condition of the afterimage pattern.
8. The display device of claim 6 , wherein the polarity signal controller changes the first polarity control signal and the second polarity control signal from one to the other by a predetermined frame period, when the frame image data do not satisfy the condition of the afterimage pattern.
9. The display device of claim 1 , wherein the afterimage pattern includes a black image and a white image which are arranged as a grid shape.
10. The display device of claim 1 , wherein the data driver comprises:
a gamma voltage generator which generates gamma-data into a gamma voltage of the positive polarity or a gamma voltage of the negative polarity based on the polarity control signal; and
a digital-to-analog converter which converts image data to the data voltage of the positive polarity or the data voltage of the negative polarity using the gamma voltage of the positive polarity or the gamma voltage of the negative polarity.
11. A method of driving a display device which comprises a pixel connected to a data line and a gate line, the method comprising:
analyzing whether frame image data satisfy a condition of an afterimage pattern;
generating a polarity control signal to control a polarity of a data voltage applied to the data line to be a positive polarity or a negative polarity with respect to a reference voltage; and
outputting the data voltage of the positive polarity or the negative polarity to the data line based on the polarity control signal by a horizontal period,
wherein a number greater than zero of a positive horizontal period, in which the data voltage of the positive polarity is outputted to the data line, in a frame period is different from a number greater than zero of a negative horizontal period, in which the data voltage of the negative polarity is outputted to the data line, in the same frame period when the frame image data satisfy the condition of the afterimage pattern.
12. The method of claim 11 , wherein the number of the negative horizontal period in the frame period is less than the number of the positive horizontal period in the frame period when the frame image data satisfy the condition of the afterimage pattern.
13. The method of claim 11 , wherein a difference between the number of the negative horizontal period in the frame period and the number of the positive horizontal period in the frame period increases when a charge rate difference between the data voltages of the positive polarity and the negative polarity increases.
14. The method of claim 11 , wherein the number of the negative horizontal period in the frame period and the number of the positive horizontal period in the frame period is determined based on an offset of the reference voltage by a kickback.
15. The method of claim 12 , wherein the number of the negative horizontal period in the frame period is equal to the positive horizontal period in the frame period when the frame image data do not satisfy the condition of the afterimage pattern.
16. The method of claim 11 , the generating the polarity control signal comprises:
generating a first polarity control signal to control the polarity of the data voltage based on a first polarity pattern, in which a polarity of the data voltage is predetermined for every horizontal period, and a second polarity control signal to control the polarity of the data voltage based on a second polarity pattern which is inverted with the first polarity pattern.
17. The method of claim 16 , the generating the polarity control signal further comprises:
changing the first polarity control signal and the second polarity control signal from one to the other by a predetermined horizontal period, when the frame image data satisfy the condition of the afterimage pattern.
18. The method of claim 16 , the generating the polarity control signal further comprises:
changing the first polarity control signal and the second polarity control signal from one to the other by a predetermined frame period, when the frame image data do not satisfy the condition of the afterimage pattern.
19. The method of claim 11 , wherein the afterimage pattern includes a black image and a white image which are arranged as a grid shape.
20. The method of claim 11 , further comprising:
generating gamma-data into a gamma voltage of the positive polarity or a gamma voltage of the negative polarity based on the polarity control signal; and
converting image data to the data voltage of the positive polarity or the data voltage of the negative polarity using the gamma voltage of the positive polarity or the gamma voltage of the negative polarity.