高分辨率多点触控红外触摸屏设计  

Design of high resolution infrared multi-touch screen

作　　者：吕燚[1] 邓春健[1,2] 李文生[1,2] 

机构地区：[1]电子科技大学中山学院,广东中山528400 [2]电子科技大学计算机科学与工程学院,四川成都610054

出　　处：《液晶与显示》2015年第1期77-82,共6页Chinese Journal of Liquid Crystals and Displays

基　　金：国家自然科学基金项目(No.61302115);广东省自然科学基金(No.S2013010015764);广东省高等学校优秀青年教师培养计划(Yq2013204);中山市产学研项目(No.2013C2FC0019)(No.2013C2FC0014)

摘　　要：红外触摸屏是大尺寸触摸屏的首选方案,但是实际应用中红外触摸屏普遍存在分辨率不高、响应速度较慢的不足,而且生产环节存在加工组装复杂的弊端。针对以上不足,提出了一种红外屏设计方案。硬件部分设计了二维选通红外扫描电路、接收电路和滤波电路,实现了发射与接收电路的模块化,为加工组装提供了便利。软件部分首先提出了脉冲式红外扫描方式,并给出了基于STM32F205片内Timer和ADC的脉冲扫描实现方法,提高了红外屏的扫描速度;然后介绍了细分扫描的设计思路,并通过二次细分扫描在不增加硬件成本的基础上提高了红外屏触点的定位精度。最后介绍了支持多点触摸的HID报告描述符的实现方法,实现了红外屏免驱安装。实际证明,该设计方案降低了加工制造复杂度,实现了红外屏即插即用,有效地提高了红外触摸屏的分辨率和响应速度。Infrared Touch Screen is the first option for big size touch screen,however,in actual application,there are some general deficiencies like insufficient resolution,low response speed and complicated fabrication and assembling process in mass production.To improve these defects,a design scheme of infrared screen is proposed.In hardware section,the two-dimension strobe infrared scanning circuit,receiving circuit and filtering circuit are incorporated to modularize the transmitting and receiving circuits and facilitate the fabrication and assembling process.In software section,apulse infrared scanning method is proposed first and the approaches to the pulse scanning based on Timer and ADC built in STM32F205 is also defined,by which the scanning speed of infrared screen is improved.Then the design idea of rescanning is introduced to improve the positioning accuracy of touching pointon infrared screen by rescanning without cost increase in hardware.At last,the approaches to HID report descriptor which supports multiple points touching is described to realize the driver-free installation of infrared screen.The actual application proves that the design lessens the fabrication complexity and fulfill the plug-and-play function and effectively improved the definition and response speed of infrared touch screen.

关 键 词：红外触摸屏 二维选通电路 脉冲扫描 多点触控 

分 类 号：TP334[自动化与计算机技术—计算机系统结构]