利用激光二极管作为光源，对红外触摸屏的原始结构加以改进，用激光和导光管的组合来取代单排发光二极管，设计了一种具有微结构的导光管.导光管采用PMMA材料，其折射率n2=1.49，在全反射的条件下，导光管微结构的几何参量通过解方程的方式获取.分别建立了导光管的光学和机械模型,建模结果表明，本文所提出的触摸屏的设计方法能够改善传统红外触摸屏存在的分辨率低、触摸方式受限制和易受环境干扰而误动作等技术上的局限，同时彻底改善了原始红外触摸屏的性能,从而克服技术和物理规律限制，满足红外触摸屏的提高分辨率和实现大尺寸的要求.

Taking the laser diode as the light source, the traditional inner structure of touch screen is improved using a light pipe with microstructures. The single row of LED is replaced by a combination of the laser and the light pipe. Light pipe uses PMMA as the material, of which the refractive index n2=1.49. In the total reflection conditions, the geometric parameters of the light pipe′s micro-structure can be solved by a certain equation. The optical and mechanical models of the light pipe are established respectively, and the results show that this proposed design method achieve high resolution ratio and large size of the touch screen.