| 摘要 |
An active matrix display device comprises an array of display pixels, each pixel comprising a current-driven light emitting display element (2), a drive transistor (22) for driving a current through the display element (2) and a storage capacitor (30) for storing a voltage to be used for addressing the drive transistor (22). A discharge transistor (36) is used for discharging the storage capacitor (30) thereby to switch off the drive transistor in dependence on the light output of the display element (2). The storage capacitor (30) is adapted to store a voltage which is a function of the threshold voltage of the drive transistor (22). In this way, two-level compensation is provided for threshold voltage variations of the drive transistor, one using a current sampling approach and one using optical feedback. This can extend the lifetime of the display. |
