Abstract
Active matrix organic light- emitting displays have many advantages, such as high contrast ratio, high brightness, low operation voltage, and flexibility; however, nonuniform brightness problem, or MURA, has to be solved. We propose two solutions to this problem. Firstly, we use photo-sensitive resistor to change the brightness of LED. Secondly, the function of non-volatile memory is added to one of the two transistors in the driving circuit. We use light to change the threshold voltage of the transistor and adjust the brightness. In the first scheme, we not only improve the uniformity of brightness but also increase the on/off ratio of LED. In the second scheme, the threshold voltage increases upon illumination. The shift in threshold voltage of non-volatile memory increases with the intensity of light. We discover that illumination in the source region of the transistor results in more threshold voltage shift than in the drain region. The scheme works in both short-channel and long-channel non-volatile memory transistor.