Organic light emitting display having compensation for transistor threshold variation

An organic light emitting display, comprising:

• a demux coupled to data lines, the demux configured to receive a data voltage at an input and to apply the data voltage through an output to the data lines;
• and
• a plurality of pixel circuits coupled to the data lines, wherein the data voltage is supplied to each pixel circuit according to a scan signal,
• wherein the scan signal and a turn-on emission control signal are simultaneously supplied to each of the pixel circuits, and
• wherein the pixel circuits are each coupled to a scan line and a data line, the pixel circuits each comprising:
• a first switching transistor comprising a control electrode coupled to the scan line, a first electrode coupled to the data line;
• a driving transistor coupled between a first power supply line and a second power supply line, the driving transistor comprising a control electrode coupled to the first switching transistor;
• a first storage capacitor coupled to the first power supply line and directly connected to the first switching transistor and the driving transistor;
• a second switching transistor coupled to the first power supply line and the driving transistor, and comprising a control electrode coupled to an emission control line;
• a second storage capacitor coupled to the second switching transistor and directly connected to the first switching transistor, the first storage capacitor, and the driving transistor;
• and
• an organic light emitting diode coupled to the driving transistor and the second power supply line.