Patent ID: 6809710
Filing Date: 2004-10-26
Classification: G09G

Abstract:
A circuit for driving a light emitting diode in a display using a current supply, said circuit comprising: a first transistor having a source, a drain, and a gate; a current supply connected to the first transistor source; an anode terminal of a light emitting diode connected to the first transistor drain; and a means for applying a combination of at least two voltages to the first transistor gate so as to control the time that the current supply is connected to the light emitting diode, wherein said means for applying comprises: second and third transistors, each having a source, a drain, and a gate; a first voltage source connected to the second transistor gate; a second voltage source connected to the second transistor source and the third transistor drain; a third voltage source connected to the third transistor gate; a capacitor having first and second terminals; a fourth voltage source connected to the first capacitor terminal; and a node connected to the second transistor drain, the third transistor source, the second capacitor terminal, and the first transistor gate.