Simplified Compensation Pixel Circuit Based on LTPS TFTs for High-Quality images of High-Resolution AMOLED Displays

Abstract

This work proposes a simplified pixel circuit that involves only four low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) and two capacitors especially for high-resolution active matrix organic light-emitting diode (AMOLED) displays. The proposed circuit adopts the simultaneous emission driving method to extend the compensating time for precisely sensing the threshold voltage variation of driving TFTs. Moreover, the flicker phenomenon is ameliorated by adjusting the voltage level of ELVSS during the programming period. Simulation results show that the relative current error rates under various data voltages with VTH variation of driving TFT of ± 0.5 V are all less than 4.5%, demonstrating that the proposed pixel circuit can generate uniform driving currents flowing through OLEDs for high-quality images.