Using Integrated Optical Feedback to Counter Pixel Aging and Stabilize Light Output of Organic LED Display Technology

We define a metric of useful operating lifetime of an organic light-emitting device (OLED) display and relate it to the commonly measured half-life of constituent OLED pixels. We enumerate sources of OLED operational instability and propose an optical feedback solution in a novel integrated configuration to counter pixel aging and maintain stable light output across all of the pixels of an OLED display. Such optical feedback can correct pixel imperfections in both active matrix and passive matrix OLED displays. As an example, we analyze lifetime data previously published by Kwong et al., in 2002, and demonstrate that our optical feedback technique could maintain 100 cd/m² display light output within a 2% brightness accuracy for more than 25 000 hours of continuous use for this specific OLED system. From this example we draw conclusions generally applicable to extending stable operating lifetime of other OLED structures.