玻璃表面缺陷单面成像

A single side detection technology for glass surface defects

为解决薄玻璃等透明介质表面缺陷检测中上下表面检测区分困难的问题,提出一种基于菲涅尔公式的玻璃表面单面成像方法。方法利用线偏振光经过反射和折射后偏振特性的变化规律,优化入射光的入射角和偏振方向使上下表面成像光的偏振方向接近正交,再利用偏振片的滤光特性选择所需光线成像。通过理论计算和仿真分析得出入射光的最佳入射角和振动方位角,在分光计上进行实验验证,并设置评价函数对不同入射角所成像进行评估。实验证明,方法能够有效消除透明介质上下表面中其中任意一面的反射光线,实现单面选择成像。经过评价函数评价分析认为入射角较小的情况下成像效果较好。该方法简单可靠,不会损害检测样品,容易投入实际生产。

In order to solve the problem that it is difficult to distinguish the upper and lower surfaces in the surface defect detection of transparent media,a single-sided imaging method of glass surface based on Fresnel formula is proposed.In this method,the change law of light polarization characteristics after reflection and refraction of linearly polarized light is used to optimize the incident angle and polarization direction of incident light,so that the polarization direction of imaging light on the upper and lower surfaces is close to orthogonal,and then the filtering characteristics of polarizer are used to select the required light for imaging.The optimal incident angle and polarization direction are obtained through theoretical calculation and simulation analysis,which are verified by experiments on the spectrometer,and the evaluation function is set to evaluate the imaging at different incident angles.Experiments show that this method can effectively eliminate the reflected light on any side of the upper and lower surfaces of transparent media,so as to realize single-sided selective imaging.After the evaluation and analysis of the evaluation function,it is found that the imaging effect is better when the incident angle is small.The scheme is simple and reliable,will not damage the test samples,and is easy to put into actual production.