Gate Driver Circuit Using Pre-Charge Structure and Time-Division Multiplexing Driving Scheme for Active-Matrix LCDs Integrated with In-Cell Touch Structures

Abstract

This paper presents a new gate driver circuit for active-matrix liquid crystal displays with an in-cell touch structure designed by hydrogenated amorphous silicon thin-film transistors. To increase the reporting rate of a touch panel, the proposed circuit can be used to pause display operations to perform touch sensing operations several times per frame. The proposed circuit exploits a pre-charge structure that alleviates the leakage current and long-term stress of a driving TFT during the touch sensing operation. Simulation results confirm that the proposed gate driver circuit can generate a highly uniform output waveform after each touch sensing operation that lasts for 200 μs when the circuit is operate at 85 °C. The variations of the rising and falling time are suppressed below 3.71%, confirming the feasibility of use of the proposed gate driver circuit for an in-cell touch panel.