Hybrid Voltage and Current Programming Pixel Circuit for High Brightness Simultaneous Emission AMOLED Display

This paper describes a new simultaneous emission AMOLED pixel circuit to achieve high brightness. Unlike the previous simultaneous emission scheme, the proposed one allows the programming operation to take place at the same time with the emission of OLEDs, which leads to high brightness. The proposed hybrid pixel circuit consists of programming and driving parts. The programming part compensates for the threshold voltage variation by means of a voltage programming scheme and the driving part is updated from the programming part through the internal current programming scheme. The SPICE simulation ensures that the proposed scheme dramatically reduces the average current error to 1.5% and 4.0% as to the threshold voltage variations of ±0.2 V and ±0.5 V, respectively. In addition, because approximately the whole frame time can be secured for the emission period, the output luminance loss is alleviated substantially compared with the previous method.