METHOD AND APPARATUS FOR MANAGING AND UNIFORMLY MAINTAINING PIXEL CIRCUITRY IN A FLAT PANEL DISPLAY

摘要

The present invention describes a method and apparatus for measuring the voltage and current characteristics of the OLED pixel as it ages and correlating the measured data to the decrease in quantum efficiency and changes in OLED impedance over the life of the OLED, so that corrections can be made to the image drive system to prevent image sticking and color point drift. The method and apparatus of the present invention do not require any additional circuitry or changes in the display design. The circuitry of the present invention is implemented in the display driver integrated circuit (IC) chips. The basis of the invention is the luminance-current-voltage (LIV) curves which characterize the OLED materials over their life time. A series of these curves are stored in memory representing a OLED material at various ages. The apparatus of the present invention is used to measure driver voltages and currents for a pixel having an OLED, which measurements are then used to extract the voltage current curve for the OLED at any point in time. The extracted curve is compared to the aging curves stored in memory to determine the aging curve that best describes the measured present voltage current characteristic of the pixel. That aging curve is used to drive the pixel.