The afterimage compensation circuit may acquire a current amount, of which a current value is reduced with respect to an existing current value. The afterimage compensation circuit may compensate for the deterioration of the pixel by applying the reduced current amount to the OLED.

The cooling time necessary for the afterimage compensation of the display panel 150 may be 55 minutes, but this is merely an example. The cooling time may be changed according to the size of the display panel 150 and the model of the display panel 150.

The reason why the cooling time of a predetermined time is secured before the afterimage compensation is that, if the afterimage compensation is performed in a state in which the display panel 150 is not sufficiently cooled, the temperature of the display panel 150 is high and an excessive voltage is sensed, and thus the afterimage compensation is not accurately performed.

If the discharge-uncompleted signal is output through the discharge check terminal 136, or if the discharge-completed signal has not yet been output, the processor 190 may determine that the cooling time of the display panel 150 is not satisfied. In this case, if AC power is supplied, the processor 190 may output a notification indicating that the cooling time is not satisfied through the display panel 150.

Then, the processor 190 may perform an operation for securing the cooling time of the display panel 150. The operation for securing the cooling time of the display panel 150 may be an operation of turning off a screen of the display panel 150.

If the cooling time of the display panel 150 is secured, the processor 190 may perform the afterimage compensation algorithm.