New Compensating Pixel Circuit to Mitigate Impact of Leakage Currents on OLED Currents for AMOLED Displays

This work presents a pixel circuit which consists a matching TFT to compensate for the threshold voltage $(\mathrm{V}_{\text{TH}})$ of the driving TFT for use in low-frame-rate displays. A leakage compensation scheme is proposed to alleviate the distortion of the OLED driving current caused by the large leakage currents of low-temperature polycrystalline silicon thin-film transistors (L TPS TFTs) in the prolonged emission time. Simulation results show that the relative current error rates over the entire data voltage range are all below 3.9% as the $\mathrm{V}_{\text{TH}}$ of the driving TFT varies by $\pm 0.5$ V. Moreover, the variations in the OLED driving current are significantly decreased, verifying the feasibility of applying the proposed circuit to low- frame-rate wearable displays.