PIXEL CIRCUIT OF VOLTAGE COMPENSATION TYPE OF ACTIVE MATRIX ORGANIC LIGHT EMITTING DIODE DISPLAY DEVICE

摘要

PURPOSE: A voltage compensation pixel circuit of an active matrix organic LED display is provided to prevent changing a gate potential of a driving thin film transistor (TFT) according to a line load deviation, thereby minimizing brightness non-uniformity. CONSTITUTION: A sensing TFT (Tsen) supplies a reference voltage to a first node in response to a reset signal. A scan TFT (Ts) supplies a data voltage to a second node in response to a scan signal. A reset TFR (Tres) supplies an initializing voltage to a third node between a driving TFT and a light emitting element in response to the reset signal. A first storage capacitor (Cst1) detects a critical voltage of the driving TFT while the driving TFT is operated by the reference voltage and stores the critical voltage of the driving TFT. A second storage capacitor (Cst2) charges the data voltage supplied to the second node. A coupling capacitor (Cc) prevents voltage variation of the first node when the sensing TFT is turned off.