A new AC biased pixel circuit for active matrix organic light-emitting diode displays

This work presents a new pixel circuit and driving scheme for active-matrix organic light-emitting diode (AMOLED) displays, where the OLED is under AC bias. The proposed pixel circuit consists of five thin film transistors (TFTs) and one capacitor. Due to the AC bias, the OLED is reverse biased during the non-emission period, which not only prevents the OLED from light emitting during the programming period to ensure a high contrast ratio displays; but also suppresses the OLED degradation and thus extends the lifetime of the AMOLED displays. It is verified that the proposed circuit can compensate for the threshold voltage variations of the driving TFT and the OLED.