Display device and driving method thereof
A display device includes: a display panel including a plurality of pixels; a data driver configured to supply a black voltage to the display panel; and a controller configured to: set an initial driving power voltage of the display panel; decide a bright spot voltage of the display panel while the data driver is supplying the black voltage to the display panel; and set any one of the bright spot voltage and the initial driving power voltage as a final driving power voltage.
1. A display device comprising:
a display panel including a plurality of pixels connected to data lines;
a data driver configured to supply a black voltage corresponding to a black grayscale through the data lines to the display panel; and
a controller configured to:
set a second voltage of the display panel to be an initial voltage;
change the second voltage at a preset interval within a threshold range while the data driver is supplying the black voltage to the display panel through the data lines;
measure a current of the display panel corresponding to each change of the second voltage at the preset interval;
decide a bright spot voltage of the display panel; and
set any one of the bright spot voltage and the second voltage as a final voltage provided to the display panel,
wherein the controller is configured to determine a reference current according to the second voltage, and to decide, as the bright spot voltage, the second voltage when a difference between the reference current and the measured current exceeds a preset threshold value.
2. The display device of claim 1 , wherein the threshold range includes the second voltage.
3. The display device of claim 1 , wherein, when the measured current is approximated to an arbitrary quadratic equation, the reference current is defined by a tangent line of the quadratic equation at second voltage.
4. The display device of claim 1 , wherein the controller is configured to set, as the final voltage, a large voltage between the second voltage and the bright spot voltage.
5. The display device of claim 1 , wherein the second voltage is a low-potential voltage.
6. A method for driving a display device having a display panel including a plurality of pixels connected to data lines, the method comprising:
setting a second voltage of the display panel to be an initial voltage;
changing the second voltage at a preset interval within a threshold range while a black voltage corresponding to a black grayscale is being supplied to the display panel through the data lines;
measuring a current of the display panel, corresponding to each change of the second voltage at the preset interval;
deciding a bright spot voltage; and
setting any one of a voltage of the bright spot voltage and the second voltage as a final voltage provided to the display panel,
wherein the deciding of the bright spot voltage includes:
determining a reference current according to the second voltage;
comparing the reference current and the measured current; and
deciding, as the bright spot voltage, the changed second voltage when a difference between the reference current and the measured current exceeds a preset threshold value, based on the comparison result.
7. The method of claim 6 , wherein the threshold range includes the second voltage.
8. The method of claim 6 , wherein the determining of the reference current includes:
approximating the measured current to an arbitrary quadratic equation; and
defining the reference current, based on a tangent line of the quadratic equation at the second voltage.
9. The method of claim 6 , wherein the setting of the final voltage includes:
comparing the second voltage and the bright spot voltage;
when second voltage is larger than the bright spot voltage, setting the second voltage as the final voltage; and
when the bright spot voltage is larger than the second voltage, setting the bright spot voltage as the final voltage.
10. The method of claim 6 , wherein the second voltage is a low-potential voltage.