Patent ID: 8217861

Claim:
A pixel circuit comprising: an organic light emitting diode having an anode that receives a driving current, and a cathode that is adapted for coupling to a first voltage source; and a driving circuit including: a switch unit that is operable in one of an on state and an off state according to a scan signal, and that is adapted for permitting transfer of a data signal when operating in the on state; a capacitor having a first end that is coupled electrically to said switch unit, and a second end; a first transistor having a first terminal that is adapted for coupling to a second voltage source, a second terminal that is coupled electrically to said second end of said capacitor and to said anode of said organic light emitting diode, and a control terminal that is coupled electrically to said first end of said capacitor; and a second transistor having a first terminal that is coupled directly and electrically to said second end of said capacitor and to said anode of said organic light emitting diode, a second terminal that is adapted for receiving a bias voltage having a value such that said second transistor operates in the saturation region, and a control terminal that is coupled directly and electrically to said first terminal of said second transistor.