That is, even if the voltage measured at the reference point K3 is equal to the predetermined voltage, the reset IC circuit 140 may output the discharge-completed signal or in some embodiments the discharge-uncompleted signal so as to prevent the occurrence of the unknown period.

Referring to FIG. 8, a fourth waveform 830 shows a waveform of the voltage measured at the reference point K3 if the reset IC circuit 140 is included in the discharge circuit 700.

It can be seen from the fourth waveform 830 that no unknown period is present in the process of changing the first voltage B to the second voltage A. This is because, due to the presence of the reset IC circuit 140, it is designed to output only the discharge-completed signal or in some embodiments the discharge-uncompleted signal.

In the case of using the reset IC circuit 140, the unknown period is not present, and thus the cooling time of the display panel 140 may be more accurately measured. Therefore, the afterimage compensation of the display panel 140 may be stably performed.

Next, a method of operating an OLED display apparatus, according to another embodiment of the present disclosure, will be described with reference to FIG. 9.

In particular, FIG. 9 is a flowchart of a method of preventing the afterimage compensation algorithm from being driven, even though the cooling time of the display panel 150 is not satisfied, in a case where the FET or the capacitor is burnt or cracked.