US Patent 7327357 Pixel circuit and light emitting display comprising the same

A pixel circuit including a light emitting device; a driving transistor to receive first power and supply current corresponding to voltage applied to a gate electrode thereof to the light emitting device; a first switching device to supply a data signal in response to a first scan signal; a second switching device to supply second power to the gate electrode of the driving transistor in response to the first scan signal; a capacitor to store voltage corresponding to the data signal and the second power according to operations of the first and second switching devices; a third switching device to apply voltage corresponding to the voltage stored in the capacitor to the gate electrode of the driving transistor in response to a second scan signal; and a fourth switching device to transmit the first power to the driving transistor in response to a third scan signal.