Machine vision system has great significance for the automatic inspection to enhance unclear defects. For the purpose of the improvement of the recognition accuracy in the automation inspection, in addition to development of image-processing technology, the optical technology is also required to emphasize the contrast of defects difficult to find in a camera. Here, we develop both the optical-engineering and image-processing technology with high throughput to enhance defects in transparent material, using the phase-shift illumination method with striped structured illumination. We succeeded in the enhancement of shape defects difficult to visualize in a bright-field observation with our approach to construct the composite image from a few pictures. Our theoretical model clarified the relationship of the composite image to parameters about optical configuration and edge sharpness of surface structures in a target material, and reproduced dependencies of the index in the experiment. Based on the theoretical model, we proposed the optimum design parameters of the equipment for enhancing the scratches in our transmissive phase-shift-illumination method, so that we can maximize the magnitude of enhancement due to the refraction of light rays in the defect shape.

机器视觉系统对于增强不清晰缺陷的自动检测具有重要意义。为了提高自动化检测中的识别精度，除了图像处理技术的发展外，还要求光学技术强调相机中难以发现的缺陷的对比度。在这里，我们开发了具有高吞吐量的光学工程和图像处理技术，以增强透明材料中的缺陷，使用具有条纹结构照明的相移照明方法。通过我们从几张图片构建合成图像的方法，我们成功地增强了在明场观察中难以可视化的形状缺陷。我们的理论模型阐明了合成图像与目标材料表面结构的光学配置和边缘清晰度参数的关系，并在实验中再现了指数的依赖性。基于理论模型，我们提出了透射相移照明方法中用于增强划痕的设备的最佳设计参数，以便我们可以最大限度地提高由于光线在缺陷形状中的折射而引起的增强幅度。