Patent ID: 7978156
Filing Date: 2011-07-12
Classification: G09G

Abstract:
1. A pixel circuit of an organic electroluminescent (EL) display device comprising a plurality of pixels and a plurality of emission lines connected to the pixels, the pixel circuit comprising: an organic EL diode connected to a source of a reference voltage and adapted to emit light at a luminance corresponding to an applied driving current; a driving transistor connected between a source of a power supply voltage and the organic EL diode and adapted to output the driving current corresponding to a voltage applied to a gate of the driving transistor; a threshold voltage compensation transistor connected between the gate and a drain of the driving transistor and adapted to electrically connect the gate and the drain of the driving transistor in response to a scan signal applied to a gate of the threshold voltage compensation transistor; a capacitor having a first electrode connected to the gate of the driving transistor and adapted to maintain a gate voltage of the driving transistor for a period of time; a switching transistor connected between a second electrode of the capacitor and a data line and adapted to apply a data voltage from the data line to the second electrode of the capacitor in response to the scan signal applied to a gate of the switching transistor; an emission control transistor connected between the driving transistor and the organic EL diode and adapted to transmit or cut off the driving current in response to a current emission control signal applied to a gate of the emission control transistor; and a compensation voltage applying transistor connected between a source of a compensation voltage and the second electrode of the capacitor and adapted to transmit the compensation voltage to the second electrode of the capacitor in response to a previous emission control signal applied to a gate of the compensation voltage applying transistor; wherein the previous emission control signal is an emission control signal of a previous one of the pixels.