Pixel circuit including N-type transistors and organic electroluminescent display apparatus using the same

An organic electroluminescent display apparatus comprising:

• a plurality of pixels;
• a first scan driver for outputting an emission control signal to each of the plurality of pixels and a second scan driver for outputting a scan control signal;
• and
• a data driver for generating a data signal and outputting the generated data signal to each of the plurality of pixels,
• wherein each of the plurality of pixels comprises:
• an organic light emitting diode comprising an anode electrode and a cathode electrode;
• a first transistor comprising a first electrode and a second electrode and for outputting a drive current according to a voltage applied to a gate electrode of the first transistor;
• a first capacitor comprising a first terminal and a second terminal coupled to the gate electrode of the first transistor;
• a second transistor for transferring the data signal to the first terminal of the first capacitor in response to the scan control signal applied to a gate electrode of the second transistor;
• a third transistor for diode-connecting the first transistor in response to the scan control signal applied to a gate electrode of the third transistor;
• a fourth transistor for applying the first power voltage to the first electrode of the first transistor in response to the emission control signal;
• and
• a fifth transistor for applying a sustain voltage to the first terminal of the first capacitor in response to the emission control signal, and
• wherein the first transistor and the second to fifth transistors are N-type transistors, and
• wherein the first scan driver and the second scan driver are driven in a first period, a second period, a third period, and a fourth period,
• the second scan driver is configured to output in the first period the scan control signal at a first level, and the first scan driver is configured to output in the first period the emission control signal at the first level;
• the data driver is configured to output in the second period the data signal having an effective level to the pixel, the second scan driver is configured to output in the second period the scan control signal at the first level, and the first scan driver is configured to output in the second period the emission control signal at a second level;
• the second scan driver is configured to output in the third period the scan control signal at the second level, and the first scan driver is configured to output in the third period the emission control signal at the second level;
• and
• the second scan driver is configured to output in the fourth period the scan control signal at the second level, and the first scan driver is configured to output in the third period the emission control signal at the first level, and
• wherein the first level is a level at which the first transistor and the second, third, fourth, and fifth transistors are turned on, and the second level is a level at which the first transistor and the second, third, fourth, and fifth transistors are turned off.