Patent ID: 6778151
Filing Date: 2004-08-17
Classification: G09G

Abstract:
A driving circuit for driving the light-emitting device a display and capable of preventing any accumulation of charges, wherein the light-emitting diode has an anode and a cathode, the driving circuit comprising:a first transistor having a drain terminal, a gate terminal and a source terminal, wherein the drain terminal of the first transistor is coupled to a data line, and the gate terminal of the first transistor is coupled to a scanning line; a storage capacitor having a first terminal and a second terminal, wherein the first terminal of the capacitor is coupled to the source terminal of the first transistor and the second terminal of the capacitor is coupled to the anode; a second transistor having a drain terminal, a gate terminal and a source terminal, wherein the drain terminal of the second transistor is coupled to a first voltage source, the gate terminal of the second transistor is coupled to the source terminal of the first transistor and the first terminal of the capacitor, and the source terminal of the second transistor is coupled to the anode and the second terminal of the capacitor; a third transistor having a drain terminal, a gate terminal and a source terminal, wherein the drain terminal of the third transistor is coupled to the first voltage source and the drain terminal of the second transistor, and the gate terminal of the third transistor is coupled to the source terminal of the third transistor, the anode and the second terminal of the capacitor; and a fourth transistor having a drain terminal, a gate terminal and a source terminal, wherein the drain terminal of the fourth transistor is coupled to the gate terminal of the third transistor, the source terminal of the third transistor, the source terminal of the second transistor, the anode and the second terminal of the capacitor, and the gate terminal of the fourth transistor is coupled to the source terminal of the fourth transistor, the cathode and a second voltage source; wherein the first voltage source is at a potential greater than the anode and the second voltage source is at a potential smaller than the anode during normal operation.