Pulsewidth Modulation With Current Uniformization for AM-OLEDs

We propose a novel conception of driving methods, pulsewidth modulation with current uniformization, for active-matrix organic light-emitting diode displays (AM-OLEDs). This driving conception can simultaneously achieve precise grayscale and exceedingly improve luminance uniformity. We evaluate a concrete example, in which a pixel circuit includes seven transistors and a driving period consists of addressing-programming and light-emitting periods. The working and the tolerance against characteristic deviations of thin-film transistors and OLEDs are confirmed using circuit simulation and actual equivalent circuits.