Poly-Si active matrix organic light-emitting diode pixel circuit with compensation for threshold voltage and mobility variations

A new pixel circuit and driving method for large-area, high-luminance active matrix organic light-emitting diode (AMOLED) displays were studied to improve the image quality. The AMOLED display was designed with low-temperature poly-silicon thin film transistors (TFTs), which have good stability but poor uniformity. To overcome the uniformity problem, the proposed pixel circuit compensates for variations in the threshold voltage and the mobility of the driving TFT. The proposed pixel circuit can operate in two compensation modes for high-luminance operation; and the black data insertion was introduced to improve the characteristics of moving images. The pixel circuit was designed for an 11.6"WXGA top-emission AMOLED panel, and its non-uniformity was estimated to be <; 4% with a mobility compensation time of 1 μs.