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

• Published in: Journal of display technology Vol. 12; no. 11; pp. 1238 - 1241
• Main Authors: Lin, Chih-Lung, Deng, Ming-Yang, Wu, Chia-En, Chen, Po-Syun, Wang, Ming-Xun
• Format: Journal Article
• Language: English
• Published: IEEE 01.11.2016
• Subjects: Driver circuits; Gate driver; hydrogenated amorphous silicon (a-Si:H); in-cell touch; Integrated circuit modeling; Leakage currents; Logic gates; Sensors; shift register; Stress; Thin film transistors; thin film transistors (TFTs)
• ISSN: 1551-319X; 1558-9323
• DOI: 10.1109/JDT.2016.2601948

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.