Patent ID: 8928564
Filing Date: 2015-01-06
Classification: G09G,H01L

Abstract:
1. A pixel circuit of a flat panel display device, comprising: a first transistor having a first gate electrode coupled to a scan line, a second electrode coupled to a data line, a second gate electrode coupled to a controlling signal line, and a first electrode; a second transistor having a first gate electrode coupled to the first electrode of the first transistor, a second electrode coupled to a first voltage source, a second gate electrode coupled to the controlling signal line, and a first electrode; a capacitor coupled between the first gate electrode of the second transistor and the first electrode of the second transistor; and an organic light emitting diode coupled between the first electrode of the second transistor and a second voltage source, wherein each of the first and second transistors further comprises: wherein the controlling signal line is configured to supply a control signal to constantly maintain threshold voltages of the first and second transistors, and wherein the second transistor is configured to supply a constant current to the organic light emitting diode in response to the control signal.