Multiple-Threshold-Voltage-Compensation Driving Scheme Using the Dimming Period To Stabilize the OLED Luminance at Low Gray Levels

We propose a multiple-threshold-voltage-compensation (MTVC) driving scheme using the dimming period to improve the luminance uniformity of AMOLED displays at low gray levels. Using HSPICE, we find that the MTVC driving scheme successfully improves the OLED current error rate compared with the conventional single-threshold-voltage-compensation driving scheme. At a low gray level, for example, the current level of 183 pA, the OLED current error rates decrease about 17% and 22% when $\mathrm{V} _{\mathrm{th}}$ shifts by 0.5 V and −0.5 V, respectively.