Patent ID: 8134523

Claim:
An active matrix display device comprising an array of display pixels, each pixel comprising: a current-driven light emitting display element; a drive transistor for driving a current through the display element; a storage capacitor (C s ) for storing a voltage to be used for addressing the drive transistor; and a light-dependent device for effecting discharge of the storage capacitor in dependence on the light output of the light emitting display element, wherein power is provided to each pixel from a first power line, and wherein one of the light dependent device and the storage capacitor is coupled to a second power supply line, and wherein the device further comprises means for varying the voltage on the second power supply line during a pixel illumination period, and wherein the voltage on the second power supply line is ramped during a pixel illumination period to cancel a leakage current I L at a gate node of the drive transistor by creating a current of opposite magnitude of the leakage current I L .