P‐9: Student Poster:Two‐Mode PWM Driven Micro‐LED Displays with Dual‐Gate Metal‐Oxide TFTs

A two‐mode pulse width modulation (PWM) pixel circuit is proposed for Micro‐LED display. The proposed driving method divides the consecutive 8 sub‐frames (256 gray levels) into low‐bit and high‐bit subframes, which are respectively driven by simultaneous emission (SE) and progressive emission (PE) modes. Compared with the traditional PWM driving scheme, the proposed one shows an increased effective luminous time ratio by 40% for a frame rate of 120Hz, which benefits higher power conversion efficiency. There are only 5 dual‐gate metal‐oxide transistors for the pixel circuit, while a source‐follower structure is adopted to extract the threshold‐voltage shift(ΔVth). Simulation results demonstrate that the current error rates can be reduced to 2% with ΔVth of ± 1 V for various grayscales.