LTPS Pixel Circuit Using Additional Capacitor Structure to Prevent Leakage Current for Low-Frame-Rate Displays

This paper proposes a pixel circuit combining with a leakage current prevention mechanism for use in wearable AMOLED displays. The pixel circuit consists of nine TFTs and two capacitors to eliminate the variations of the driving current caused by the threshold voltage (V
_TH
) variations of the driving TFT. The variation of the voltage at the gate node of the driving TFT is compensated for by using a capacitor to store a specific voltage to minimize the leakage current of LTPS TFTs. Moreover, the proposed circuit prevents the current from flowing through the OLED during the programming period. The simulation results indicate that the proposed pixel circuit successfully compensates for the variations of V
_TH
of the driving TFT and solves the leakage current problem. Therefore, the proposed pixel circuit is appropriate for low- frame-rate displays.