Pixel and organic light emitting display device using the same

摘要

A pixel circuit and an organic light emitting display using the pixel circuit are disclosed. The pixel circuit compensates for variation of the threshold voltage of a driving transistor and for variation in the power supply to the pixel.

主权项

1. An organic light emitting display device, comprising:
a pixel unit comprising a plurality of pixels circuits; a data driving unit configured to supply a data signal to the pixel unit; a power supply unit configured to supply a first pixel power, a second pixel power, a first compensation power, and a second compensation power to the pixel unit; and a scanning driving unit configured to selectively supply the data signal, the first pixel power, the second pixel power, the first compensation power, and the second compensation power to the pixel unit such that pixel electric current corresponding to the data signal flows to the pixel, wherein each of the pixel circuits includes:
an organic light emitting diode configured to emit light according to a pixel electric current flowing from a first pixel power supply to a second pixel power supply;a first transistor comprising a first electrode connected to the first pixel power supply, a second electrode connected to a first node, and a gate connected to a second node, wherein the pixel electric current flows from the first electrode to the second electrode, according to a voltage of the gate;a second transistor configured to selectively supply a data signal to a third node;a third transistor configured to selectively connect the second electrode of the first transistor with the gate of the first transistor;a fourth transistor configured to selectively supply a voltage of an initialization power supply directly to the second node;a fifth transistor configured to selectively supply a voltage of a first compensation power supply directly to the third node, wherein the first compensation power supply is different from each of the first pixel power supply, the second pixel power supply and the initialization power supply;a sixth transistor configured to selectively supply a voltage directly to a fourth node;a seventh transistor configured to selectively supply the pixel electric current to the organic light emitting diode;a first capacitor directly connected to the second node and the fourth node; anda second capacitor directly connected to the third node and the fourth node.