P‐71: Digital PWM Driving MicroLED Pixel Circuit using a‐ITZO TFTs

Micro light‐emitting diode (micro‐LED) displays show significant potential for large‐area display applications; however, challenges such as external quantum efficiency (EQE) variations and wavelength shift remain. To address these issues, a pixel circuit utilizing the pulse width modulation (PWM) driving method is proposed, offering low power consumption and superior display performance for modular displays. Additionally, an external compensation mechanism is introduced to minimize the number of thin‐film transistors (TFTs) and input signals required, ensuring enhanced efficiency and simplified design. The proposed 5T1C pixel circuit operates in three distinct periods—initial & programming, emission, and reset—and utilizes amorphous indium‐tin‐zinc oxide (a‐ITZO) TFTs. The circuit operates PWM compensation technique that adjusts pulse width using additional extra‐bits, significantly reducing memory requirements and data driver complexity compared to conventional methods. Experimental results demonstrate successful operation of the fabricated a‐ITZO TFT pixel array and gate driver, with verified brightness variations across gray levels, confirming its suitability for micro‐LED modular displays.