Life time extension method for simultaneous emission driving AMOLED displays

Abstract

A life time extension method for simultaneous emission driving active matrix organic light emitting diode (AMOLED) displays is proposed. The proposed driving method extends emission time by driving even and odd row lines separately. The extended emission time reduces organic light emitting diode (OLED) degradation because the current density of the OLED decreases as emission time increases. The proposed driving method increases the emission time by 50% compared with the conventional simultaneous emission driving method. Measurement results show the proposed driving method increases the OLED life time by 70.07% when the target luminance of the OLED is 300 cd/m2 and the life time is assumed that the time until the OLED luminance becomes 75% of the initial luminance. The proposed pixel structure using the even-odd separation driving scheme compensates the electrical characteristic variation of the polycrystalline-silicon thin film transistors and the maximum luminance error of pixel to pixel is 0.26% in a 3.8-inch AMOLED panel.