The light emitting cell may be formed to have a structure of hole transport layer/organic emission layer/electron transport layer or a structure of hole injection layer/hole transport layer/organic emission layer/electron transport layer/electron injection layer. In addition, the light-emitting cell may further include a functional layer for improving the luminescent efficiency and/or lifespan of the organic emission layer.

The pixel circuit supplies the OLED with a data current corresponding to a data voltage supplied from a data driver to a data line in response to a gate signal of a gate-on voltage level supplied from a gate driver to a gate line.

At this time, the data voltage has a voltage value in which deterioration characteristics of the OLED are compensated. To this end, the pixel circuit includes a switching transistor, a driving transistor, and at least one capacitor, which are formed on a substrate by a thin film transistor forming process. The switching transistor and the driving transistor may be a-Si TFT, poly-Si TFT, oxide TFT, organic TFT, or the like.

The switching transistor may supply a gate electrode of the driving transistor with the data voltage supplied to the data line according to the gate signal of the gate-on voltage level supplied to the gate line.

Since the driving transistor is turned on according to a gate-source voltage including the data voltage supplied from the switching transistor, it is possible to control a current amount flowing from a driving voltage line (PL1) to the OLED.

The memory 170 may store the cooling time of the display panel 150. Although described below, the cooling time may be the time during which the display panel 150 must be turned off for afterimage compensation of the display panel 150.