In-cell触控屏用两级预充电栅极驱动电路  

A gate driver circuit with the two-stage pre-charge structure for in-cell touch panels

作　　者：沈帅 廖聪维[1] 杨激文 张盛东[1] Shuai SHEN;Congwei LIAO;Jiwen YANG;Shengdong ZHANG(Shenzhen Graduate School,Peking University,Shenzhen 518055,China;Century Technology(Shenzhen)Corporation,Ltd.,Shenzhen 518110,China)

机构地区：[1]北京大学深圳研究生院,深圳518055 [2]深超光电(深圳)有限公司,深圳518110

出　　处：《中国科学：信息科学》2021年第6期1030-1040,共11页Scientia Sinica(Informationis)

基　　金：国家自然科学基金(批准号:61774010);深圳市科技计划(批准号:GGFW2017072816344703)资助项目。

摘　　要：由于触控侦测阶段的保持电荷损失和驱动晶体管的阈值电压漂移,传统的栅极驱动电路用于高触控侦测率的内嵌式(in-cell)电容触控屏时存在稳定性不佳的问题.本文提出了一种具有两级预充电结构的栅极驱动电路,可有效地减少触控侦测阶段的保持电荷损失量,并抑制驱动晶体管的阈值电压漂移.仿真结果表明,传统栅极驱动电路和新栅极驱动电路的邻近级输出波形延迟时间的差异分别是9.3%和1.6%.在关键晶体管的阈值电压正向漂移10 V后,传统栅极驱动电路和新栅极驱动电路输出波形延迟时间的增加比率分别为120%和2.4%.因此,本文提出的新型栅极驱动电路具有较好的稳定性,适用于高触控侦测率的in-cell电容触控屏.Due to the charge leakage during the touch sensing period and the threshold voltage shift of the driving thin-film transistors(TFTs),the conventional gate driver circuits suffer from poor stability for in-cell touch displays with an increased touch reporting rate.This paper shows a new gate driver circuit,consisting of a two-stage pre-charge structure,which can reduce the charge leakage during the touch sensing period and suppress the threshold voltage shift of the driving TFTs.Simulation results demonstrate that,the rising and falling time differences between adjacent stages are 9.3%and 1.6%for the conventional and the proposed gate driver circuit,respectively.In the case that the threshold voltage of key TFT shifts by+10 V,the rising and falling time degradation ratios are 120%and 2.4%for the conventional and the proposed gate driver circuit,respectively.Therefore,the proposed gate driver circuit is stable for in-cell touch panels with a high touch reporting rate.

关 键 词：内嵌式电容触控屏 栅极驱动电路 稳定性 氢化非晶硅 薄膜晶体管 时分驱动 

分 类 号：TN873[电子电信—信息与通信工程]