结合暗场散射与曲率成像的镜面缺陷检测方法

Research on mirror defect detection technology combining curvature and dark field imaging

在镜面表面缺陷检测技术中,常用的暗场成像检测法对于波纹类的三维镜面缺陷难以形成对比度,为此提出了一种结合暗场散射法和曲率成像法的综合型镜面表面缺陷检测方法。分别对暗场成像原理和基于条纹反射的曲率成像原理进行了理论分析;构建了结合两种成像模块的综合型镜面缺陷检测的实验装置;对注塑反射镜和抛光玻璃薄片两种样品进行了缺陷成像实验。实验结果表明,暗场散射成像可以有效检测麻点、划痕和油污等不同类型镜面缺陷,曲率分布图像可以清晰反映镜面表面的三维波纹缺陷,综合两种方法可以全面反映镜面表面的各类缺陷。该方法可为精密光学元件表面缺陷检测提供参考。

In the mirror surface defect detection technology,the commonly used dark field imaging detection method is difficult to form contrast for the corrugated three-dimensional mirror surface defects.In this paper,a mirror surface defect detection method based on dark field scattering and curvature imaging is proposed to realize the comprehensive detection of different types of mirror surface defects.The dark field imaging principle and the curvature imaging principle based on the fringe reflection method are analyzed theoretically.A mirror defect detection device combining the two imaging modules is constructed.Defect imaging experiments are carried out on two kinds of samples,the injection mirror and the polished substrate glass sheet.The experimental results show that the dark field scattering imaging can effectively detect pits,scratches and oil stains.The curvature distribution image can clearly reflect the three-dimensional wavy defects on the surface.The combination of the two modes can completely find all kinds of defects on the surface of the mirror sample.This method has an important significance for the research of precision optical element surface defect detection.