Display device and method of driving the same

1 . A display device comprising:

a display panel comprising pixels;

a power management circuit configured to provide a voltage to the display panel through a power voltage line, and configured to decrease the voltage when a power current of the display panel flowing through the power voltage line is greater than a reference current; and

a controller configured to control the power management circuit, and comprising:

a panel degradation calculator configured to calculate a panel degradation amount of the display panel;

a maximum power current calculator configured to calculate a maximum power current of the display panel based on the panel degradation amount; and

a reference current calculator configured to calculate the reference current by multiplying the maximum power current by a gain.

2 . The display device of claim 1 , wherein the panel degradation calculator comprises:

a block stress accumulator configured to calculate ages of blocks comprising at least one pixel among the pixels by accumulating stresses of the blocks; and

a block degradation calculator configured to calculate block degradation amounts of the blocks based on the ages of the blocks.

3 . The display device of claim 2 , wherein the panel degradation amount is equal to a maximum block degradation amount among the block degradation amounts.

4 . The display device of claim 2 , wherein the controller further comprises a degradation compensator configured to convert input image data into output image data based on the block degradation amounts.

5 . The display device of claim 1 , further comprising a sensing circuit configured to measure sensing values for the pixels,

wherein the panel degradation calculator comprises a pixel degradation calculator configured to calculate pixel degradation amounts of the pixels based on the sensing values.

6 . The display device of claim 5 , wherein the panel degradation amount is equal to a maximum pixel degradation amount among the pixel degradation amounts.

7 . The display device of claim 5 , wherein the controller further comprises a degradation compensator which configured to convert input image data into output image data based on the pixel degradation amounts.

8 . The display device of claim 1 , wherein the gain is configured to remain constant regardless of a driving time of the display panel.

9 . The display device of claim 1 , wherein the gain is configured to decrease as a driving time of the display panel increases.

10 . The display device of claim 9 , wherein the gain is greater than 1.

11 . The display device of claim 1 , wherein the power current is a sum of driving currents flowing through light-emitting elements of the pixels.

12 . The display device of claim 1 , wherein the maximum power current corresponds to a maximum luminance of an image displayed by the display panel.

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

calculating a panel degradation amount of a display panel comprising pixels;

calculating a maximum power current of the display panel based on the panel degradation amount;

calculating a reference current by multiplying the maximum power current by a gain; and

decreasing a voltage of the display panel when a power current of the display panel is greater than the reference current.

14 . The method of claim 13 , wherein calculating the panel degradation amount comprises:

calculating ages of blocks each comprising at least one pixel among the pixels by accumulating stresses of the blocks; and

calculating block degradation amounts of the blocks based on the ages of the blocks.

15 . The method of claim 14 , wherein the panel degradation amount is equal to a maximum block degradation amount among the block degradation amounts.

16 . The method of claim 13 , wherein calculating the panel degradation amount comprises:

measuring sensing values for the pixels; and

calculating pixel degradation amounts of the pixels based on the sensing values.

17 . The method of claim 16 , wherein the panel degradation amount is equal to a maximum pixel degradation amount among the pixel degradation amounts.

18 . The method of claim 13 , further comprising maintaining the gain as constant regardless of a driving time of the display panel.

19 . The method of claim 13 , further comprising decreasing the gain as a driving time of the display panel increases.

20 . The method of claim 19 , wherein the gain is greater than 1.