Improvement of brightness uniformity by AC driving scheme for AMOLED display

Abstract

We propose an ac voltage driving scheme which can improve the brightness uniformity of active-matrix organic light-emitting diode (AMOLED) displays. Through the use of a charge feed-through mechanism and an ac driving voltage, the voltage drop caused by the parasitic resistance can be compensated. A 2.2 in AMOLED panel with a resolution of 176 x RGB x 220 has been fabricated by low temperature polycrystalline silicon technology to evaluate the performance of the ac driving scheme. Experimental results show that a brightness uniformity of higher than 91.6%, achieved by the ac driving scheme, in contrast to that of 74% achieved by a dc driving scheme.