ELECTROLUMINESCENT DISPLAY DEVICES AN ACTIVE MATRIX

摘要

An active matrix EL display has first and second capacitors connected in series between the gate and source or drain of a pixel drive transistor. A data input to the pixel is provided to the junction between the first and second capacitors thereby to charge the second capacitor to a voltage derived from the pixel data voltage, and a voltage derived from the drive transistor threshold voltage being stored on the first capacitor. A discharge transistor is connected between the junction between the first and second capacitors and a common line for all pixels of the display. This device uses a common line as a discharge sink/source for the threshold voltage measurement operation. By avoiding the use of a data line for this purpose, the pixel can be in a non-addressed state when the threshold measurement takes place.