PIXEL CIRCUIT AND OLED DISPLAY DEVICE USING THE SAME

摘要

PURPOSE: A pixel circuit and an OLED(Organic Light Emitting Diode) display device using the same are provided to form uniformly the luminance of an OLED device by generating the driving current including a non-uniform threshold voltage of a polysilicon TFT. CONSTITUTION: A pixel circuit includes the first transistor(TFT1), the second transistor(TFT2), the first capacitor(C1), the third transistor(TFT3), the fourth transistor(TFT4), and the second capacitor(C2). The first transistor(TFT1) is used for receiving the voltage from data lines and outputting the driving current to an OLED. The second transistor(TFT2) is turned on or off according to a selective pulse through the first scan line in order to output the voltage to a gate terminal of the first transistor(TFT1). The first capacitor(C1) is used for storing a voltage difference between the gate terminal and a source terminal of the first transistor(TFT1). The third transistor(TFT3) is turned on or off according to the selective pulse through the first scan line in order to connect the first capacitor(C1) to the source terminal of the first transistor(TFT1). The fourth transistor(TFT4) is turned on or off according to the selective pulse through the second scan line in order to output the voltage of the data line to the outside. The second capacitor(C2) is used for storing the output voltage of the fourth transistor.