TRANSISTOR CONTROL CIRCUITS AND CONTROL METHODS, AND ACTIVE MATRIX DISPLAY DEVICES USING THE SAME

摘要

A transistor control circuit (74) comprises a source-gated thin film transistor (70), an input for receiving a drive voltage representing a desired control of the source-gated transistor and a current source (82) for causing a known current to pass through the source-gated transistor (70). A first capacitor (78) stores a resulting gate-source voltage of the source-gated transistor when the known current is passed through the source-gated transistor. The drive voltage is modified using the resulting gate-source voltage, and the modified voltage is used in the control of the source-gated transistor. This control can provide a translational shift in the operating characteristics of the transistor, and it has been found that this can compensate for ageing of the transistor, for non-uniformity between different devices, and for temperature variations.