Patent ID: 8264426

Claim:
An organic light emitting display device comprising: a display region comprising pixels for displaying an image; a scan driver comprising scan signal circuits for applying a scan signal to select the pixels; a data driver for applying a data signal to the selected pixels; and an emission control driver for applying an emission control signal for controlling an emission operation of the pixels, wherein at least one of the scan signal circuits of the scan driver includes a three-transistor flip-flop having only three transistors, two of which are configured to be driven by a same control signal, the three-transistor flip-flop including: a first transistor, coupled between a constant positive power supply voltage terminal configured to supply a constant positive power supply voltage, and a signal line for the scan signal, and configured to turn on/off by the same control signal being applied to a gate terminal of the first transistor; a second transistor, connected between the signal line for the scan signal and either a signal line for a clock signal or a signal line for an inverted clock signal, and configured to turn on/off according to a voltage at a gate terminal of the second transistor; a third transistor comprising a first electrode coupled to the gate terminal of the second transistor, and a second electrode configured to transmit an input signal to the first electrode by the same control signal being applied to a gate terminal of the third transistor; and a control signal input portion, commonly coupled to the gate terminal of the first transistor and the gate terminal of the third transistor, and for applying the same control signal of a low or high level in response to either a clock signal or an inverted clock signal.