Robust Bidirectional Gate Driver on Array Based on Indium Gallium Zinc Oxide Thin-Film Transistor for In-Cell Touch Displays

Abstract

In this paper, we propose a bidirectional gate driver on array (GOA) circuit design based on indium gallium zinc oxide (IGZO) thin-film transistor (TFT) to support time-division driving method (TDDM) for in-cell touch displays. The proposed circuit allows the touch panel to pause the display for touch sensing operations to achieve a touch reporting rate as twice as the frame rate of a display. A dual low-level maintaining unit design is used to suppress influence of the threshold voltage shift of TFTs through alternately turning on the devices. Owing to recovery of threshold voltage shift under negative bias, this design can maintain stable performance during long time operation. A narrow border 6.5” in-cell LCD panel of 90 Hz display with a 180 Hz touch reporting rate is finally demonstrated.