In a pixel PX-1, while the data voltage according to the data signal D[j] is applied to the gate (i.e., the first node N1) of the first transistor T1, the second node N2 and the anode may be electrically separated by the third transistor T3, which is in the turned-off state. Accordingly, when a current leakage flowing to the anode from the first power ELVDD occurs through the first transistor T1, the data voltage applied to the second node N2 and the gate of the first transistor T1 by the third transistor T3 in the turned-off state is not affected so that display quality can be improved.

In the light emission period PA4, the first power ELVDD has the third voltage level ELVDD_H, the initialization power VINT has the fifth voltage level VINT_H, and the second power ELVSS has the sixth voltage level ELVSS_L. The scan signal S[i] may have the gate-off voltage level VGH. That is, in the light emission period PA4, the initialization power VINT increased to the fifth voltage level VINT_H from the fourth voltage level VINT_L, and the voltage V_N1 (i.e., a voltage of the gate of the driving transistor) of the first node N1 may be increased corresponding to the variation amount (i.e., VINT_H-VINT_L) of the initialization power VINT. Accordingly, a driving current based on a voltage difference between the gate and the first end of the first transistor T1 is generated and flows to the organic light emitting diode OLED through the first transistor T1, and thus pixels can simultaneously emit light.